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112
https://medicalsciences.stackexchange.com/questions/9521/is-crunching-sound-in-the-neck-normal
[ { "answer_id": 9522, "body": "<p>You're asking about so called <strong>articular release</strong>. It is considered a normal condition.</p>\n\n<p>From \"<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/12033758\" rel=\"noreferrer\">Joint cracking and popping: understanding noises that accompany articular release.</a>\" (2002):</p>\n\n<blockquote>\n <p>The sound, or the noise,\n is what people notice in articular release; the subjective relief\n it provides is secondary. (...)\n The sound generated by joint manipulation has been classified\n variously throughout osteopathic medical literature, being\n referred to as an “articular crack,” “articular pop,” “clunk,”\n “crepitus,” “joint click,” “snap,” “synovial grind,” and “thud,”\n and it has been described as a “grating” sound in the general\n medical literature (Figure 3). The articular release may be accompanied\n by a loud audible release or a soft joint sound—but it can\n also be inaudible. (...) <strong>The articular crack occurs for patients in both healthy and diseased states. It can be heard during normal functioning.</strong></p>\n</blockquote>\n\n<p>About long-term, habitual cracking:</p>\n\n<blockquote>\n <p>Is articular release necessary to maintain joint health? (...) A person who\n undergoes habitual cracking does so for the feeling of relief and\n greater motion in the involved joint. If one were to consider the\n anatomic and physiologic models solely, one could assume\n that maintaining motion throughout the joint could lower the\n likelihood of developing osteoarthritis. On the other hand, the\n excessive use of a joint could lead to laxity of the ligaments supporting\n the joint, causing hypermobility or introducing an\n unnecessary stress that could eventually cause dysfunction. </p>\n</blockquote>\n\n<p>There is nothing about the neck, but there is about knuckles, as researchers are generally more interested in investigating knuckle and hand cracking:</p>\n\n<blockquote>\n <p>Swezey and Swezey studied the prevalence of knuckle\n cracking in geriatric men in comparison to 11-year-old children\n and found that their data failed to show that cracking leads to\n degenerative joint disease in the MCP joint in old age. <strong>The\n chief morbid consequence of habitual joint cracking appeared\n to be the annoyance inflicted on the casual observer.</strong></p>\n</blockquote>\n\n<p>If you're more interested in what exactly causes this strange sounds, I recommend reading <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4398549/\" rel=\"noreferrer\">\"Real-Time Visualization of Joint Cavitation</a>\" (2015). There is a very interesting history section. But the final conclusion is:</p>\n\n<blockquote>\n <p>Our data support the view that tribonucleation is the process which governs joint cracking. This process is characterized by rapid separation of surfaces with subsequent cavity formation, not bubble collapse as has been the prevailing viewpoint for more than a half century. </p>\n</blockquote>\n", "score": 7 }, { "answer_id": 19761, "body": "<p>Its called <strong>Articular release</strong>!</p>\n\n<p>Articular release is a physiologic event that may or may not be audible. It is seen in patients with healthy joints as well as those with somatic dysfunction. After an articular release, there is a difference in joint spacing-with the release increasing the distance between articular surfaces. Not all noise that emanates from a joint signifies an articular release.</p>\n\n<p><a href=\"https://www.researchgate.net/publication/11338336_Joint_cracking_and_popping_Understanding_noises_that_accompany_articular_release\" rel=\"nofollow noreferrer\">source</a></p>\n", "score": 1 } ]
9,521
CC BY-SA 3.0
Is crunching sound in the neck normal?
[ "neck", "popping-cracking-joints" ]
<p>Some people have a crunching (grating, cracking, popping) sound when they turn a head. Considering we're talking about long-term condition without any pain, is it considered a normal condition?</p>
7
https://medicalsciences.stackexchange.com/questions/9691/wearing-a-corset
[ { "answer_id": 9701, "body": "<h1>1. Does wearing a corset have any disadvantages?</h1>\n<p>Yes.</p>\n<p>The wearing of a corset for extended periods of time to maintain or reduce waist size is called tightlacing. It is commented (though nowhere I can cite) that to effectively tightlace you need to use a Victorian-style steel/bone corset as modern elastic/rubber/plastic corsets don't exert enough force.</p>\n<p>A typical tightlacing training routine begins with the use of a well-fitted corset and introduces very gradual decreases in the waist circumference. <strong>Lacing too tight too fast can cause extreme discomfort and short-term problems such as shortness of breath and faintness, indigestion, and chafing of the skin if a liner is not worn.</strong></p>\n<p>The diminished waist and tight corset reduce the volume of the torso. This is sometimes reduced even further by styles of corset that force the torso to taper towards the waist, <strong>which pushes the lower ribs inwards</strong>. <strong>Internal organs are moved closer together and out of their original positions in a way similar to the way that a pregnant woman's expanding uterus causes the organs to be displaced.</strong></p>\n<p><strong>The volume of the lungs diminishes and the tightlacer tends to breathe intercostally – that is, with the upper portion of the lungs only. Due to the lower portion of the lungs being used less there is often a stereotype of mucosal build-up there; a slight and persistent cough is the sign of the body trying to clear this.</strong></p>\n<p>For more information on the effects on individual organs please see this <a href=\"https://en.wikipedia.org/wiki/Effects_of_tightlacing_on_the_body#Muscles\" rel=\"nofollow noreferrer\">Wikipedia Commons article</a>.</p>\n<p>Feel free to google any of the above, its simple biology. You cant magically break the rules of thermodynamics or human biology by squeezing your waist.</p>\n<h1>2. What if I wear it for 8 hours a day?</h1>\n<p>The same as above still applies.</p>\n<h1>3. Does a corset affect the skin ( or as I read the fat under the skin )?</h1>\n<p>In a way, it moves it around which does 'affect' it.</p>\n<p>It does not build muscle and may lead to atrophy of your abdominals due to them not being used to stabilise you (as you rely on the corset).</p>\n<p>For more information: <a href=\"https://en.wikipedia.org/wiki/Tightlacing\" rel=\"nofollow noreferrer\">https://en.wikipedia.org/wiki/Tightlacing</a></p>\n<p>There are some benefits to tempory waist restriction, <a href=\"http://www.strongerbyscience.com/the-belt-bible/\" rel=\"nofollow noreferrer\">when power/weightlifting a tight belt can be used to brace ones core against so that the persons posture is kept more rigid at higher weights. It can even help develop abdominal strength by giving you resistance to push against</a></p>\n", "score": 3 } ]
9,691
CC BY-SA 3.0
Wearing a corset
[ "dermatology", "body-fat", "clothes", "body-shape", "diaphragm" ]
<p>First of all, I am not an english native speaker, however I will try to explain my issue as clear as possible. I am not asking for any diagnosis, but to clarify my question I will share my personal story . </p> <p>My work needs about eight hours daily sitting in front of a computer. For that, trying to keep by body healthy, I start a new program, in which I change my food habits into healthier ones, and try to do exercises three times a week plus taking a walk daily for 20 min.</p> <p>However dueto stress I am still facing a problem : I am thin, even though all fats are accumilating in the abs and waist!</p> <p>I was thinking that, maybe wearing a coreset can prevent this accumilation of fat. So I did some research on different corsets products. However, what I found is that: as many warning of wearing such corset as many encouragings for wearing it. Maybe this is due to commercial facts.</p> <p>My question is : From medical poin of view, Does wearing a corset has any disadvantages? What if I wear it for 8 hours a day ? does a corset affect the skin ( or as I read the fat under the skin ) ? </p>
7
https://medicalsciences.stackexchange.com/questions/9720/should-eating-before-bedtime-be-avoided-if-someone-wants-to-lose-weight
[ { "answer_id": 15620, "body": "<p>There is some experimental evidence that suggests that those who front load ( have their main meals earlier in the day ) are more likely to lose weight than those who eat later.</p>\n\n<p><strong>BACKGROUND</strong>:\nThere is emerging literature demonstrating a relationship between the timing of feeding and weight regulation in animals. However, whether the timing of food intake influences the success of a weight-loss diet in humans is unknown.</p>\n\n<p><strong>OBJECTIVE</strong>:\nTo evaluate the role of food timing in weight-loss effectiveness in a sample of 420 individuals who followed a 20-week weight-loss treatment.</p>\n\n<p><strong>METHODS</strong>:\nParticipants (49.5% female subjects; age (mean ± s.d.): 42 ± 11 years; BMI: 31.4 ± 5.4 kg m(-2)) were grouped in early eaters and late eaters, according to the timing of the main meal (lunch in this Mediterranean population). 51% of the subjects were early eaters and 49% were late eaters (lunch time before and after 1500 hours, respectively), energy intake and expenditure, appetite hormones, CLOCK genotype, sleep duration and chronotype were studied.</p>\n\n<p><strong>RESULTS</strong>:\nLate lunch eaters lost less weight and displayed a slower weight-loss rate during the 20 weeks of treatment than early eaters (P=0.002). Surprisingly, energy intake, dietary composition, estimated energy expenditure, appetite hormones and sleep duration was similar between both groups. Nevertheless, late eaters were more evening types, had less energetic breakfasts and skipped breakfast more frequently that early eaters (all; P&lt;0.05). CLOCK rs4580704 single nucleotide polymorphism (SNP) associated with the timing of the main meal (P=0.015) with a higher frequency of minor allele (C) carriers among the late eaters (P=0.041). Neither sleep duration, nor CLOCK SNPs or morning/evening chronotype was independently associated with weight loss (all; P>0.05).</p>\n\n<p><strong>CONCLUSIONS:</strong>\nEating late may influence the success of weight-loss therapy. Novel therapeutic strategies should incorporate not only the caloric intake and macronutrient distribution - as is classically done - but also the timing of food.</p>\n\n<p><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23357955\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pubmed/23357955</a></p>\n\n<p>Another paper suggests that there are metabolic sequelae if you have your main calories late in the day</p>\n\n<p><strong>Abstract</strong>\n<strong>Objective</strong>\nFew studies examined the association between time-of-day of nutrient intake and the metabolic syndrome. Our goal was to compare a weight loss diet with high caloric intake during breakfast to an isocaloric diet with high caloric intake at dinner.</p>\n\n<p><strong>Design and Methods</strong>\nOverweight and obese women (BMI 32.4 ± 1.8 kg/m2) with metabolic syndrome were randomized into two isocaloric (∼1400 kcal) weight loss groups, a breakfast (BF) (700 kcal breakfast, 500 kcal lunch, 200 kcal dinner) or a dinner (D) group (200 kcal breakfast, 500 kcal lunch, 700 kcal dinner) for 12 weeks.</p>\n\n<p><strong>Results</strong>\nThe BF group showed greater weight loss and waist circumference reduction. Although fasting glucose, insulin, and ghrelin were reduced in both groups, fasting glucose, insulin, and HOMA-IR decreased significantly to a greater extent in the BF group. Mean triglyceride levels decreased by 33.6% in the BF group, but increased by 14.6% in the D group. Oral glucose tolerance test led to a greater decrease of glucose and insulin in the BF group. In response to meal challenges, the overall daily glucose, insulin, ghrelin, and mean hunger scores were significantly lower, whereas mean satiety scores were significantly higher in the BF group.</p>\n\n<p><strong>Conclusions</strong>\nHigh-calorie breakfast with reduced intake at dinner is beneficial and might be a useful alternative for the management of obesity and metabolic syndrome.</p>\n\n<p><a href=\"http://onlinelibrary.wiley.com/doi/10.1002/oby.20460/abstract\" rel=\"nofollow noreferrer\">http://onlinelibrary.wiley.com/doi/10.1002/oby.20460/abstract</a></p>\n", "score": 3 } ]
9,720
CC BY-SA 3.0
Should eating before bedtime be avoided if someone wants to lose weight?
[ "diet", "sleep", "weight-loss", "time-of-day", "body-weight" ]
<p>I have read many contradictory articles regarding eating before bedtime for someone trying to lose weight. Here some examples:</p> <p><a href="http://www.nytimes.com/2011/05/17/health/17really.html?_r=4&amp;adxnnl=1&amp;adxnnlx=1335121216-Q4q6iChMxGm7qr5Lq3+Jsg" rel="nofollow">http://www.nytimes.com/2011/05/17/health/17really.html?_r=4&amp;adxnnl=1&amp;adxnnlx=1335121216-Q4q6iChMxGm7qr5Lq3+Jsg</a></p> <p><a href="http://time.com/3020266/you-asked-will-eating-before-bed-make-me-fat/" rel="nofollow">http://time.com/3020266/you-asked-will-eating-before-bed-make-me-fat/</a></p> <p><strong>Are there any proven evidence in the literature that eating before bedtime favors or prevents weight loss?</strong></p>
7
https://medicalsciences.stackexchange.com/questions/9876/how-to-shave-pubic-hair-and-prevent-razor-burn-and-ingrown-hair
[ { "answer_id": 9885, "body": "<p>You should trim the pubic hair preferably with scissors before shaving.</p>\n\n<p>You may even consider only trimming alone. But if you must shave, then trim first. Also endeavour to stretch your skin before shaving. And apply Aloe Vera after shaving. Some would recommend Hydrocortisone, but I'm not a fan of medications....I'm a fan of trimming :)</p>\n\n<p><a href=\"http://www.livestrong.com/article/176437-how-to-keep-pubic-area-from-itching-after-shaving/\" rel=\"noreferrer\">http://www.livestrong.com/article/176437-how-to-keep-pubic-area-from-itching-after-shaving/</a></p>\n\n<p><a href=\"http://m.wikihow.com/Shave-Your-Pubic-Hair\" rel=\"noreferrer\">http://m.wikihow.com/Shave-Your-Pubic-Hair</a></p>\n", "score": 5 }, { "answer_id": 9902, "body": "<p>Unfortunately ingrowns are tough to avoid unless you trim only or have had laser hair removal. But here are a few tips:</p>\n\n<ul>\n<li>trim first; hair shouldn't be more than 1/4\"</li>\n<li>use a sharp and clean razor</li>\n<li>use moisturizing shaving cream </li>\n<li>shave in the direction of hair growth</li>\n</ul>\n\n<p>After you're done and are completely dry, apply antibiotic ointment (like Neosporin) to the areas that you have shaved. Do this daily.</p>\n\n<p>Also be sure to exfoliate all shaved areas between each shave, such as with a clean cotton washcloth, etc. </p>\n", "score": 3 } ]
9,876
CC BY-SA 3.0
How to shave pubic hair and prevent razor burn and ingrown hair?
[ "inflammation", "shaving-razor-burn" ]
<p><strong>How to shave pubic hair and prevent razor burn and ingrown hair?</strong> </p> <p>It seems that every time I try to shave my pubic hair (like a bikini line), I always make it look a lot worse than before shaving... I'd much rather have a few swaths of hair than bright red inflamed razor burn and itchy red ingrown hairs.</p> <p>I always make sure my razor is sharp and clean, and that my skin isn't lather/shaving cream is non-scented (so as not to irritate my skin), and that the skin is warm from the water and well covered in lather, and then I shave. And it looks and feels good for about 24 hours, but after that.... all sorts of tiny welts bubble up and I begin itching up a storm. </p> <p><strong>Is there a certain direction to shave? Is there a different instrument I should be using instead of my razor? How do I shave my pubic hair without it backfiring on me?</strong> </p>
7
https://medicalsciences.stackexchange.com/questions/10754/does-exercise-increase-memory
[ { "answer_id": 10762, "body": "<p>Yes, with a caveat.</p>\n\n<p>There are many studies showing beneficial effects of aerobic exercise on cognition, including memory and response tasks. This also includes preventing decline in older adults by preserving hippocampus and temporal lobe size. These can be seen by the following studies involving both humans and rats:</p>\n\n<p><a href=\"http://www.pnas.org/content/108/7/3017.abstract\" rel=\"noreferrer\">Older adult study</a></p>\n\n<p><a href=\"http://psycnet.apa.org/journals/bne/121/2/324/\" rel=\"noreferrer\">Rats in mazes performance</a></p>\n\n<p><a href=\"http://www.sciencedirect.com/science/article/pii/S1755296609000052\" rel=\"noreferrer\">Memory in preadolescents</a></p>\n\n<p>However, one thing that was new to me is the effect of resistance exercise, rather than aerobic exercise on cognition. While there isn't much out there examining this mode of exercise, <a href=\"http://education.msu.edu/kin/HBCL/_articles/Pontifex_2009_TheEffectOfAcute.pdf\" rel=\"noreferrer\">this study on resistance exercise and memory</a>, as well as a couple of cited studies in the same paper, suggest that resistance exercise either does not confer the same cognitive benefits, or that it benefits in other unknown ways.</p>\n\n<p>So in short, yes, aerobic exercise does improve memory and cognition, while resistance exercise may not have the same effect.</p>\n", "score": 5 } ]
10,754
CC BY-SA 3.0
Does exercise increase memory?
[ "memory" ]
<p>So many people I have heard argue that exercise increases memory.</p> <p>I know exercise is healthy for your heart but does it really help long term or working memory?</p>
7
https://medicalsciences.stackexchange.com/questions/10760/are-color-blind-and-blind-individuals-able-to-dream-in-color
[ { "answer_id": 10780, "body": "<p>Humans (and many mammals, for that matter) are not born knowing how to use our eyes. During the first month we can only discern vague shapes and shadows beyond much more than a foot or so, though some color development takes place during that time. (References <a href=\"http://www.allaboutvision.com/parents/infants.htm\" rel=\"noreferrer\">here</a> and <a href=\"http://www.babycenter.com/0_baby-sensory-development-sight_6508.bc\" rel=\"noreferrer\"> here</a>.)<br><br>I won't go into anymore detail; the point being that the brain of a person who is born blind would never learn how to process images. And without having that experience, they would not have context in which to place those images into a dream. I think it would be reasonable to conclude that a person blind since birth could only dream in the context of their own experiences (i.e. a non-sighted world).<br><br>Similarly, a color blind (or more accurately color deficient) person could not dream in any colors they have no experience with. For example, if someone couldn't see green, then they could not see that or yellow (yellow being a combination of red and green). Since they have no experience with those colors (i.e. they have no idea what they look like), they could not have dreams with those colors in them.</p>\n", "score": 8 } ]
10,760
CC BY-SA 3.0
Are color-blind and blind individuals able to dream in color?
[ "blind", "dreams", "optic-nerve", "color-blindness", "hippocampus" ]
<p>I know that individuals who have color-blindness or complete blindness, are not able to see as vast an array of colors as most. I do understand that they can distinguish shading (dark vs. light), but I'm curious if in their dreams if they are able to experience the vibrancy of colors (since it's not delivered via the optic nerve, but rather the hippocampus)?? Would they be able to recognize color if they did (if they had blindness or colorblindness their entire lives?)</p> <p>I am by no means an expert in vision or dreams so I maybe misunderstanding this completely. Please feel free to correct me, and explain how color is perceived both through physical vision and then internally as in dreams. </p>
7
https://medicalsciences.stackexchange.com/questions/11856/is-it-safe-to-cease-masturbation-for-good
[ { "answer_id": 12028, "body": "<p>Lifelong abstainance from masterbation is completely safe. As @Noah said in his comment, there are plenty of celibate people out there with no adverse health from their life choice.</p>\n\n<p>Even though sperm is constantly being produced, dead sperm will be shed after time anyway. See my answer to a similar question at <a href=\"https://health.stackexchange.com/a/11676\">Effects of masturbation on Health</a>.</p>\n\n<p>I have also seen this good answer from @Narusan at <a href=\"https://health.stackexchange.com/a/11687\">How many times a week is masturbating good for health?</a> which mentions that there is no defined amount which is healthy or unhealthy. It is down to individual choice and health.</p>\n\n<h2>-- Edit to answer queries in the comments --</h2>\n\n<p><a href=\"https://health.stackexchange.com/users/8840/user8840\">@user8840</a> questioned this answer in the comments. He/she said,</p>\n\n<blockquote>\n <p>How about \"<a href=\"https://en.wikipedia.org/wiki/Blue_balls\" rel=\"nofollow noreferrer\">blue balls</a>\", \"the condition of temporary fluid congestion in the testicles accompanied by testicular pain\"</p>\n</blockquote>\n\n<p>I agree with what <a href=\"https://health.stackexchange.com/users/45/shadow-wizard\">@ShadowWizard</a> said, which was that</p>\n\n<blockquote>\n <p>this only applies when you're sexually aroused for long period of time. I am pretty sure this answer assumes no sexual arousal is involved.</p>\n</blockquote>\n\n<p>I would like to stress on some of the points surrounding this \"condition\", and some of these points are mentioned in the Wikipedia article linked above.</p>\n\n<ol>\n<li><p><a href=\"https://en.wikipedia.org/wiki/Vasocongestion\" rel=\"nofollow noreferrer\"><strong>Vasocongestion</strong></a>, (temporary fluid congestion) as mentioned in the link provided in the Wikipedia article, is required for erection in men and clitoral arousal in women. It is the increase in blood and pressure in the relevant body parts.</p></li>\n<li><p><strong>Blue balls</strong> is a slang term and has no official term which I have been able to find. The Wikipedia article says that some urologists call it <strong>epididymal hypertension</strong>, however, researching a bit more, <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/11015532\" rel=\"nofollow noreferrer\">one article in the journal <em>Pediatrics</em>, published in 2000</a>, discussed \"epididymal hypertension\" as a potential diagnosis in young adult males. The problem is that \"epididymal hypertension\" is a diagnosis which is a general, <em>all encompasing</em> diagnosis for all sorts of causes of testicular pain.</p></li>\n</ol>\n\n<blockquote>\n <p>The condition described, what the urologists often term “epididymal hypertension,” and some have labeled “deadly sperm buildup” or “DSB,” has many other manifestations of which physicians and their caretakers ought to be aware. (<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/11694711\" rel=\"nofollow noreferrer\">Rockney &amp; Alario, 2001</a>)</p>\n</blockquote>\n\n<p><a href=\"https://www.verywell.com/understanding-blue-balls-1298225\" rel=\"nofollow noreferrer\">another article</a> states the fact that</p>\n\n<blockquote>\n <p>The medical community hasn't spent a ton of time on this particular phenomenon. For one thing, it is absolutely non life-threatening, despite the belief otherwise by many a first time sufferer. Plus, any topic even suggesting sexuality among the sub voting aged crowd is politically charged and uncomfortable for many healthcare providers to broach with either their patients or their patients' parents (especially the moms).</p>\n \n <p>Worse yet, the immediate relief of the pain is most efficiently handled by the immediate release of the arousal. The easiest way to do this, of course, is through orgasm.</p>\n</blockquote>\n\n<ol start=\"3\">\n<li>Boys and men will often wake up with an erection in the morning, with or without stimulation or erotic dreams. These erections are sometimes referred to as \"morning wood\" or \"morning glory\".</li>\n</ol>\n\n<p>Whether the erection was nocturnal or not, <a href=\"http://www.familyplanningplus.org/8001/if-a-man-keeps-getting-hard-but-doesnt-ejaculate-does-he-develop-stomach-pains/\" rel=\"nofollow noreferrer\">the easiest (and quickest) treatment for this is ejaculation</a>. However, even without release, the condition will subside on its own within an hour or two, although it can be within minutes. Although rare, epididymal hypertension could last as long as 24 hours.</p>\n", "score": 8 } ]
11,856
CC BY-SA 3.0
Is it safe to cease masturbation for good?
[ "risks", "sociosexual-behavior", "masturbation", "breaking-habits" ]
<p>Can males safely cease masturbation if they so desire, assuming the person isn't sexually active?</p>
7
https://medicalsciences.stackexchange.com/questions/11887/resources-for-human-anatomy
[ { "answer_id": 13136, "body": "<ul>\n<li><strong><a href=\"http://teachmeanatomy.info/\" rel=\"nofollow noreferrer\">TeachMeAnatomy</a></strong></li>\n</ul>\n<blockquote>\n<p>Containing over 700 vibrant, full-colour images, TeachMeAnatomy is a comprehensive anatomy encyclopedia presented in a visually-appealing, easy-to-read format.</p>\n<p>Created by a team of doctors and medical students, each topic combines anatomical knowledge with high-yield clinical pearls, seamlessly bridging the gap between scholarly learning and improved patient care.</p>\n</blockquote>\n<p>This is a good site which mainly deals with anatomy of the human body, It also freely accessible and which can also be considered credible. Also see the <strong><a href=\"https://teachmeseries.com/\" rel=\"nofollow noreferrer\">TeachMeSeries</a></strong> which contains information about other fields of medicine.</p>\n<ul>\n<li><strong><a href=\"http://reference.medscape.com/guide/anatomy\" rel=\"nofollow noreferrer\">Medscape</a></strong></li>\n</ul>\n<blockquote>\n<p>Medscape is the leading online global destination for physicians and healthcare professionals worldwide, offering the latest medical news and expert perspectives; essential point-of-care drug and disease information; and relevant professional education and CME.</p>\n</blockquote>\n<ul>\n<li><strong><a href=\"https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology\" rel=\"nofollow noreferrer\">Khan Academy</a></strong></li>\n</ul>\n<blockquote>\n<p>Get introduced to the major organ systems of the human body! You’ll learn some general anatomy (a roadmap of your body), learn how the arm bone actually connects to the shoulder bone, and how the different organs work together to keep you alive. Watch some videos, read some articles, try some flashcards, and then quiz yourself!</p>\n</blockquote>\n<ul>\n<li><strong><a href=\"https://thesebonesofmine.wordpress.com/skeletal-basics/\" rel=\"nofollow noreferrer\">These bones of mine</a></strong></li>\n</ul>\n<blockquote>\n<p>This blog will explicitly introduce the human skeleton and its anatomical traits to a general and interested audience.</p>\n<p>This blog then is an introduction and a repository for me, detailing my interests in the field and whilst also documenting my own ongoing archaeological experience. Furthermore, I want to take you on a journey of discovery of self learning by detailing what exactly human osteologists and bioarchaeologists do. Alongside this approach I will also include details of my own extensive experience of bone disease.</p>\n<p>Up to date academic references are noted on each post explicitly and an effort is made to find an Open Access articles and resources, where available, as appropriate. Within each of these references you will find much more detail on the specific subject highlighted and also on the practice of human osteology and archaeology in general. Please enjoy and share.</p>\n</blockquote>\n<ul>\n<li><p><strong>PDFs</strong></p>\n<p>• <a href=\"https://www.gutenberg.org/ebooks/43350\" rel=\"nofollow noreferrer\">The Anatomy</a></p>\n<blockquote>\n<p>This discusses about the anatomy of human peritonium and abdominal cavity.[<a href=\"https://www.gutenberg.org/wiki/Category:Bookshelf\" rel=\"nofollow noreferrer\">From: Project Gutenberg</a>] which contains many other free access books related to other field also.</p>\n</blockquote>\n<p>• <a href=\"https://www.gutenberg.org/ebooks/24440\" rel=\"nofollow noreferrer\">Surgical Anatomy</a> [From: Project Gutenberg]</p>\n<p>• <a href=\"https://open.umn.edu/opentextbooks/BookDetail.aspx?bookId=169\" rel=\"nofollow noreferrer\">Anatomy and Physiology</a> [From: Open Textbook Library]</p>\n<p>• <a href=\"https://www.ncbi.nlm.nih.gov/books/NBK11530/?term=%22anatomy%20and%20histology%22%5BAll%20Fields%5D%20OR%20(%22anatomy%22%5BAll%20Fields%5D%20AND%20%22histology%22%5BAll%20Fields%5D)%20OR%20%22anatomy%20and%20histology%22%5BAll%20Fields%5D%20OR%20%22anatomy%22%5BAll%20Fields%5D%20OR%20%22anatomy%22%5BAll%20Fields%5D\" rel=\"nofollow noreferrer\">The organisation of the Retina and Visual System</a> [From: <a href=\"https://www.ncbi.nlm.nih.gov/books\" rel=\"nofollow noreferrer\">NCBI Bookshelf</a>]</p>\n<p>• [<a href=\"https://archive.org/stream/AnatomyByGerardJ.TortoraBryanH.Derrickson/anatomy%20by%20Gerard%20J.%20Tortora%2C%20Bryan%20H.%20Derrickson#page/n4/mode/1up\" rel=\"nofollow noreferrer\">Anatomy By Gerard J. Tortora, Bryan H. Derrickson</a>] (Thanks to @<a href=\"https://health.stackexchange.com/users/13819/gordon\">Gordon</a>)</p>\n</li>\n</ul>\n", "score": 7 }, { "answer_id": 16549, "body": "<p><a href=\"http://www.bartleby.com/107/\" rel=\"nofollow noreferrer\">Gray's Anatomy</a> - an old but complete online book with detailed text and pictures.</p>\n\n<p><a href=\"https://www.getbodysmart.com/\" rel=\"nofollow noreferrer\">Get Body Smart</a> - by organic systems, at a glance</p>\n\n<p><a href=\"http://www.innerbody.com/image/musfov.html\" rel=\"nofollow noreferrer\">Inner Body</a> - on hover interactive images, with text</p>\n\n<p><a href=\"https://www.youtube.com/results?search_query=kenhub%20anatomy\" rel=\"nofollow noreferrer\">KenHub</a> - 50 videos</p>\n\n<p><a href=\"http://anatomyzone.com/tutorials-page/\" rel=\"nofollow noreferrer\">AnatomyZone</a> - ~200 videos, including basic terminology</p>\n", "score": 4 } ]
11,887
CC BY-SA 3.0
Resources for human anatomy
[ "research", "health-education", "anatomy" ]
<p>What are <em>preferably free and preferably PDF filetype</em> online resources that one can use to study the basic anatomy of the human body?</p> <h2>Disclaimer</h2> <p>I feel like these would be great for Health.SE as we could provide a link to those resources that everyone can access instead of books that are usually very costly. I'm starting with human anatomy because this seems the most important to me. </p>
7
https://medicalsciences.stackexchange.com/questions/12164/when-is-guilt-in-depression-considered-psychotic
[ { "answer_id": 16788, "body": "<p>According to DSM-5 (American Psychiatric Association, 2013, p. 819) a <em>delusion</em> is a \"false belief based on incorrect inference about external reality that is firmly held despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary. ... When a false belief involves a value judgement it is regarded as a delusion only when the judgment is so extreme as to defy credibility.\"</p>\n\n<p>Similarly, Østergaard, et al. (2012), citing Maj, et al. (2007), state: \"To avoid false-positive diagnoses of PD [psychotic depression], only beliefs that have ‘delusional proportions’, i.e. <em>defy credibility</em>, and are held with ‘delusional intensity’, i.e. <em>not changed by rational counterarguments</em>, are classified as delusions.\" <em>(emphasis added)</em></p>\n\n<p>An intriguing possibility exists that a specific, measurable cognitive bias, the Jumping to Conclusions (JTC) bias, might serve as a marker for delusions (McLean, Mattiske, &amp; Balzan, 2017). The JTC bias is characterized by making interpretations or judgments early (quickly) and basing such interpretations or judgments on inadequate evidence. Regarding measurement:</p>\n\n<blockquote>\n <p>JTC is most frequently measured by the beads task. Applying this task\n with people with schizophrenia, Huq et al showed participants 2 jars\n of colored beads. Each jar contained pink and green beads in an 85:15\n ratio, with one jar containing mostly pink beads and the other mostly\n green beads. The jars were hidden from view and beads were drawn from\n one of the jars in a purportedly random but in fact pre-determined\n sequence. With each draw, participants were invited to indicate\n whether they had decided which jar (mostly pink or mostly green) beads\n were being drawn from. Huq et al9 found that participants with current\n delusions required fewer draws-to-decision (DTD) than those without\n current delusions, demonstrating a JTC bias. (McLean, Mattiske, &amp; Balzan, 2017, p. 345)</p>\n</blockquote>\n\n<p>Further research is needed before we will know if measuring JTC improves diagnostic accuracy.</p>\n\n<p>Stephens &amp; Graham (20014) describe four criteria that define beliefs generally: </p>\n\n<p>(1) beliefs have a representational content; </p>\n\n<p>(2) the person holding the believe has a high degree of confidence that the content of his or her belief, e.g., \"I am a horrible person\", is an accurately represents reality; </p>\n\n<p>(3) beliefs form the basis for both reasoning and action, such that individuals draw conclusions based on the belief (\"because I am a horrible person I am doomed to Hell\") and might take actions based on the belief (a Catholic person visits a priest asking, \"How do I prepare for an eternity in Hell?\"); and finally </p>\n\n<p>(4) beliefs are associated with an emotional response, e.g., a belief that one is a horrible person may engender or exacerbate feelings of sadness, shame, guilt, despair, or hopelessness.</p>\n\n<p>This four-component model of beliefs can serve as a heuristic to probe the \"delusional proportionality\" and \"delusional intensity\" of a patient's beliefs, e.g., by asking questions designed to assess the patients degree of confidence in the belief; the extent to which the patient has drawn conclusions and taken actions based on the belief; and emotions experienced when discussing the belief.</p>\n\n<p>Like many symptoms of mental disorders, if a clinician can observe and interact with a patient over time, and if the doctor can interview family members or friends who know the patient well, then determining if a belief qualifies as a delusional becomes somewhat easier. </p>\n\n<p><strong>References</strong></p>\n\n<p>American Psychiatric Association, 2013. <em>Diagnostic and statistical manual of mental disorders</em> (DSM-5®). American Psychiatric Pub. (ISBN 9780890425558).</p>\n\n<p>Maj, M., Pirozzi, R., Magliano, L., Fiorillo, A. and Bartoli, L., 2007. Phenomenology and prognostic significance of delusions in major depressive disorder: a 10-year prospective follow-up study. <em>The Journal of clinical psychiatry, 68</em>(9), pp.1411-1417.</p>\n\n<p>McLean, B.F., Mattiske, J.K. and Balzan, R.P., 2017. Association of the jumping to conclusions and evidence integration biases with delusions in psychosis: a detailed meta-analysis. <em>Schizophrenia bulletin, 43</em>(2), pp.344-354.</p>\n\n<p>Østergaard, S.D., Rothschild, A.J., Uggerby, P., Munk-Jørgensen, P., Bech, P. and Mors, O., 2012. Considerations on the ICD-11 classification of psychotic depression. <em>Psychotherapy and psychosomatics, 81</em>(3), pp.135-144.</p>\n\n<p>Stephens, G.L. and Graham, G., 2004. Reconceiving delusion. <em>International Review of Psychiatry, 16</em>(3), pp.236-241.</p>\n", "score": 2 } ]
12,164
CC BY-SA 3.0
When is guilt in depression considered psychotic?
[ "depression", "psychiatrist-psychiatry" ]
<p>Guilt is a feature of Major clinical Depression. My doubt is, can guilt be considered delusional for making a diagnosis of mood-congruent psychotic depression? Can there be a delusional guilt? Because, wouldn't a person with depression if guilty, be always firm in his belief (which is characteristic of a delusion)?</p>
7
https://medicalsciences.stackexchange.com/questions/12674/what-would-happen-if-you-administered-endothelin-during-a-myocardial-infarction
[ { "answer_id": 24442, "body": "<ol>\n<li>It seems to be still under <a href=\"https://www.nature.com/articles/hr2010215\" rel=\"nofollow noreferrer\">debate</a>. Contradictory evidence has been found.</li>\n</ol>\n<blockquote>\n<p>The relative importance of Endothelin Type A and Endothelin Type B receptors during myocardial ischaemia are still debated.</p>\n</blockquote>\n<ol start=\"2\">\n<li>The word you are seeking is <a href=\"https://en.wikipedia.org/wiki/Regeneration_in_humans#Induced_regeneration_in_humans\" rel=\"nofollow noreferrer\"><strong>regenerative</strong></a>. Mammalian hearts are made from non-regenerative tissue.</li>\n</ol>\n<blockquote>\n<p><em>&quot;While several animals can regenerate heart damage (e.g. the axolotl), mammalian cardiomyocytes (heart muscle cells) cannot proliferate (multiply) and heart damage causes scarring and fibrosis.&quot;</em></p>\n</blockquote>\n", "score": 1 } ]
12,674
CC BY-SA 3.0
What would happen if you administered endothelin during a myocardial infarction?
[ "cardiology", "practice-of-medicine", "scar-tissue-scars", "myocardial-infarction", "hyperplasia" ]
<p>I have been going through the Rhodes medical physiology and have learned about <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3141212/" rel="nofollow noreferrer">Endothelin</a> (specifically its role in hyperplasia) and collateral vessels in slowly developed [cardiovascular disease] (CVD). This makes me wonder the following things:</p> <ol> <li>Why can we not avoid the scar tissue formation that plagues <a href="http://medical-dictionary.thefreedictionary.com/myocardial+infarction" rel="nofollow noreferrer">myocardial infarction</a> (MI) survivors by administering Endothelin in a selective manner so as to make it only hit the type A receptors ?</li> <li>How plastic are heart cells?</li> </ol> <p><strong>FYI: I have no idea how the heart controls its plasticity and cell growth, but given that cancers in the heart are so rare surely the administration of endothelin would be well regulated</strong></p>
7
https://medicalsciences.stackexchange.com/questions/13252/does-frequent-masturbation-decrease-testosterone-levels-in-men
[ { "answer_id": 13257, "body": "<h2>No, <a href=\"http://www.testofuel.com/tf/does-masturbating-lower-testosterone/\" rel=\"noreferrer\">masturbation does not decrease testosterone levels in the blood</a>.</h2>\n\n<hr>\n\n<p>Relevant studies cited in the linked article:</p>\n\n<p>Fox CA, Ismail AAA, Love DN, Kirkham KE, Loraine JA. Studies on the relationship between plasma testosterone levels and human sexual activity. J Endocrinol. 1972;52:51–58.</p>\n\n<p>Batty J. Acute changes in plasma testosterone levels and their relation to measures of sexual behaviour in the male house mouse (Mus musculus) Anim. Behav. 1978;26:349–357.</p>\n\n<p>Phoenix CH, Dixson AF, Resko JA. Effects of ejaculation on levels of testosterone, cortisol, and luteinizing hormone in peripheral plasma of rhesus monkeys. J Comp Physiol Psychol. 1977;91:120–127.</p>\n", "score": 7 } ]
13,252
Does frequent masturbation decrease testosterone levels in men?
[ "masturbation", "testosterone" ]
<p>I'm just curious. Done no research into this. Can anyone explain if there is a correlation?</p>
7
https://medicalsciences.stackexchange.com/questions/13258/is-there-a-direct-correlation-between-high-testosterone-level-and-weak-immune-sy
[ { "answer_id": 23354, "body": "<p>According to this <a href=\"https://www.nature.com/articles/nri.2016.90\" rel=\"nofollow noreferrer\">2016 Nature Review article</a> (which cites the article from your link):</p>\n\n<p>Androgens have been show to reduce immune response in a variety of studies. For example:</p>\n\n<ul>\n<li>In vivo exposure to testosterone reduces NK cell activity in mice [1]</li>\n<li>In vivo and in vitro exposure to testosterone decreases TLR4 expression on macrophages in mice [2]</li>\n<li>Testosterone reduces synthesis of TNF, iNOS and NO by macrophages and increases anti-inflammatory response through TGF-b and Il-10 [3]</li>\n</ul>\n\n<p>The mechanism of action of androgenic immunosuppression seems to be due to androgen receptor's inhibitory effect on pro-inflammatory transcription factors [4].</p>\n\n<p>Sources:</p>\n\n<ol>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/3366506\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pubmed/3366506</a></li>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/18003947\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pubmed/18003947</a></li>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/10415638\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pubmed/10415638</a></li>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/10453354\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pubmed/10453354</a></li>\n</ol>\n", "score": 2 } ]
13,258
CC BY-SA 3.0
Is there a direct correlation between high testosterone level and weak immune system?
[ "immune-system", "testosterone", "correlation" ]
<p>I tried googling it, the only credible link I found is this: <a href="https://med.stanford.edu/news/all-news/2013/12/in-men-high-testosterone-can-mean-weakened-immune-response-study-finds.html" rel="noreferrer">https://med.stanford.edu/news/all-news/2013/12/in-men-high-testosterone-can-mean-weakened-immune-response-study-finds.html</a></p> <hr> <p>Can someone please tell me whether this is true. If yes, why?</p>
7
https://medicalsciences.stackexchange.com/questions/13266/how-to-get-rid-of-insomnia-naturally
[ { "answer_id": 13267, "body": "<p><a href=\"https://sleep.org/articles/sleep-hygiene/\" rel=\"noreferrer\">Sleep Hygiene.</a> Learn it, try it, and see if it resolves your issue.</p>\n\n<p>I've answered <a href=\"https://health.stackexchange.com/questions/10855/how-to-get-to-sleep-half-an-hour-an-hour-earlier-than-the-day-before/10939#10939\">this similar question before</a>.</p>\n\n<p>Insomnia has different causes. The most common, outside of poor sleep hygiene, is anxiety or depression. That's something else to consider.</p>\n\n<p>I recommend seeing your doctor in general to discuss it, they can help guide you whether there are any alarm features that might require tests or treatment, like signs of sleep apnea.</p>\n", "score": 6 }, { "answer_id": 13296, "body": "<p>Insomnia is extremely rare in indigenous populations, as <a href=\"https://www.scientificamerican.com/article/modern-hunter-gatherers-probably-get-less-sleep-than-you-do/\" rel=\"nofollow noreferrer\">mentioned in this article</a> where the sleeping habits of 94 members of the Hadza of Tanzania, the San of Namibia and the Tsimané of Bolivia were studied:</p>\n\n<blockquote>\n <p>Only 1.5 to 2.5 percent of the hunter-gatherers the researchers studied experienced insomnia more than once a year. In comparison, 10 to 30 percent of people in industrial societies report chronic insomnia, the scientists noted. Insomnia was so rare among the San and the Tsimané, they do not have a word for the disorder.</p>\n</blockquote>\n\n<p>As suggested in the article, one can then try to adopt some of the relevant lifestyle factors that are plausibly involved in sleep. A new finding was the importance of temperature:</p>\n\n<blockquote>\n <p>The scientists found that the amount of sleep these hunter-gatherers got had less to do with the length of daylight hours than with temperature. These groups sleep an hour more in the winter than they do in the summer.\n \"In natural conditions, humans sleep [more] during a period of declining temperature,\" Siegel said. \"In contrast, in most modern settings, while we may turn the temperature down at night, it is not declining.\"\n In other words, modern life has \"almost completely eliminated a major sleep regulator,\" he said.</p>\n</blockquote>\n\n<p>Another thing that is mentioned in the article is that these indigenous people sleep less than we tend to do:</p>\n\n<blockquote>\n <p>Investigations showed that these traditional peoples slept slightly less than 6.5 hours a night on average. In comparison, people in industrial societies usually average seven to eight hours per night.</p>\n</blockquote>\n\n<p>This combined with the fact that these people get a lot more exercise than most of us get radically changes the balance between sleep and daytime exertion. And the diet has a totally different balance between fats and carbohydrates. As <a href=\"https://www.theguardian.com/society/2017/mar/17/tsimane-of-the-bolivian-amazon-have-worlds-healthiest-hearts-says-study\" rel=\"nofollow noreferrer\">mentioned here</a>:</p>\n\n<blockquote>\n <p>A high carbohydrate diet of rice, plantain, manioc and corn, with a small amount of wild game and fish – plus around six hours’ exercise every day – has given the Tsimané people of the Bolivian Amazon the healthiest hearts in the world.</p>\n</blockquote>\n\n<p>.............</p>\n\n<blockquote>\n <p>Their diet is high in unrefined carbohydrates (72%) with about 14% protein and it is very low in sugar and in fat – also 14%, which amounts to about 38g of fat a day including 11g of saturated fat. </p>\n</blockquote>\n\n<p>So, the bigger picture that we don't get if we only study sleep in Western societies, is that the Western lifestyle is not so robust at preventing insomnia compared to indigenous populations. The people who sleep well in Western societies are still just one or two steps away of getting insomnia, while the way indigenous populations live, put them many more steps away from getting insomnia, which makes insomnia far less likely to occur there, so much so that their languages <a href=\"http://news.nationalgeographic.com/2015/10/20151015-paleo-sleep-time-hadza-san-tsimane-science/\" rel=\"nofollow noreferrer\">don't have a word for it</a>:</p>\n\n<blockquote>\n <p>The San and Tsimané languages have no word for insomnia, and when researchers tried to explain it to them, “they still don’t seem to quite understand,” Siegel says.</p>\n</blockquote>\n\n<p>which really emphasizes the point that insomnia just doesn't happen there, otherwise the people there would be able to understand it from their own personal experience. From my personal experience, I think that sleep time and exercise may be the most important factor. I run every day for about one hour (and quite fast with my heart rate at about 150 bpm), and I sleep on average slightly less than 7 hours a day. When I was younger I slept for 8 hours and I didn't exercise anywhere near my current level. I did have sleeping problems far more frequently than I have today. So, to me at least, this seems to be a a problem that's caused by the body getting way too much rest and way too little exertion. </p>\n", "score": 2 } ]
13,266
CC BY-SA 3.0
How to get rid of insomnia naturally?
[ "sleep", "insomnia", "breaking-habits" ]
<p>I know that sleep is important, and on weeks, that I consistently get enough sleep I feel my best. The problem is sometimes I wake in the middle of the night and can not go back to sleep for hours. I know that insomnia in general is a somewhat common problem. I do not want to take medication, but want my sleep to improve. Any suggestions would be helpful.</p>
7
https://medicalsciences.stackexchange.com/questions/13308/is-2nd-hand-smoking-worse-than-1st-hand-smoking
[ { "answer_id": 13314, "body": "<h2>TL;DR</h2>\n\n<p>Yes, if one was to inhale the same amount of smoke passively as smokers inhale actively, it would be more dangerous. This is hardly the case though, as smokers also inhale parts of second hand smoke, and because as always, <em>dosis facit venenum</em>.</p>\n\n<hr>\n\n<h2>Risk of Second Hand Smoke</h2>\n\n<p><strong>Risk of developing cancer</strong></p>\n\n<blockquote>\n <p>Exposure to secondhand smoke raises the risk -- <strong>by as much as 30 percent [1.3 times]</strong> -- that others will get lung cancer and many other types of cancer, it can lead to emphysema, and it is bad for your heart. </p>\n \n <p><em>Source: <a href=\"http://www.webmd.com/smoking-cessation/effects-of-secondhand-smoke\" rel=\"nofollow noreferrer\">WebMD</a>, Emphasis Mine, Annotation Mine</em></p>\n</blockquote>\n\n<p>The lower risk of developing cancer is because passive smokers don't inhale the same amount of smoke - you usually walk past a smoker and not stand right next to them until they have finished their cigarette.</p>\n\n<p><strong>Inhalation of toxic fumes</strong></p>\n\n<blockquote>\n <p>There are 2 types of tobacco smoke:</p>\n \n <ol>\n <li>Mainstream smoke, which is directly inhaled through the mouth end of the cigarette </li>\n <li>Sidestream smoke, which comes from the burning tip of the cigarette </li>\n </ol>\n \n <p>Second-hand smoke is made up of sidestream smoke and\n exhaled mainstream smoke, mixed with the surrounding air.</p>\n \n <p>Sidestream smoke is about <strong>4 times more toxic than mainstream smoke,\n although people inhale it in a more diluted form</strong>. This is because\n sidestream smoke contains much higher levels of many of the poisons\n and cancer-causing chemicals in cigarettes, including:</p>\n \n <ul>\n <li>At least 3 times as much carbon monoxide</li>\n <li>10-30 times more nitrosamines</li>\n <li>Between 15–300 times more ammonia </li>\n </ul>\n \n <p><em>Source: <a href=\"http://www.cancerresearchuk.org/about-cancer/causes-of-cancer/smoking-and-cancer/passive-smoking\" rel=\"nofollow noreferrer\">cancerresearchuk.org</a></em></p>\n</blockquote>\n\n<p>However, the total amount of toxic fumes passive smokers inhale is less than what smokers inhale, because the former are not exposed to smoke as often as the latter.</p>\n\n<p><strong>Risk of Developing Heart Diseases or Strokes</strong></p>\n\n<blockquote>\n <p>Breathing secondhand smoke can cause coronary heart disease, including\n heart attack and stroke. Know the facts:</p>\n \n <ul>\n <li><p>Secondhand smoke causes nearly 34,000 early deaths from coronary heart disease each year in the United States among \n nonsmokers.</p></li>\n <li><p>Nonsmokers who <strong>breathe secondhand smoke at home or at work increase<br>\n their risk of developing heart disease by 25–30%.</strong></p></li>\n <li><p>Breathing secondhand smoke interferes with the normal functioning of the heart, blood, and vascular systems in ways that increase\n your risk of having a heart attack.</p></li>\n <li>Even briefly breathing secondhand smoke can damage the lining of blood vessels and cause your blood to become stickier. These changes<br>\n can cause a deadly heart attack.</li>\n </ul>\n \n <p><em>Source: <a href=\"https://www.cdc.gov/tobacco/campaign/tips/diseases/heart-disease-stroke.html\" rel=\"nofollow noreferrer\">cdc.gov</a></em></p>\n</blockquote>\n\n<p>Again, the risk is lower than the risk of smokers because it is <em>only</em> an exposure during work or at home and are not expected to inhale the same amount of smoke as bystanders as smokers do.</p>\n\n<h2>Risks of First Hand Smoke</h2>\n\n<p><strong>Risk of developing cancer</strong></p>\n\n<blockquote>\n <p>People who smoke cigarettes are <strong>15 to 30 times more likely</strong> to get lung cancer or die from lung cancer than people who do not smoke. Even smoking a few cigarettes a day or smoking occasionally increases the risk of lung cancer. The more years a person smokes and the more cigarettes smoked each day, the more risk goes up.</p>\n \n <p><em>Source: <a href=\"https://www.cdc.gov/cancer/lung/basic_info/risk_factors.htm\" rel=\"nofollow noreferrer\">cdc.gov</a>, Emphasis Mine</em></p>\n</blockquote>\n\n<p><strong>Toxic fumes</strong></p>\n\n<blockquote>\n <p>Cigarette smoke is a mixture of over 4000 chemicals, many of which are\n harmful to the human body. All currently available tobacco products\n that are smoked deliver substantial amounts of toxic chemicals to\n their users and those who breathe their smoke.</p>\n \n <p>Of the more than 4000 chemicals present in cigarette smoke, more than\n 60 have been identified as cancer causing chemicals, 11 of which are\n known to cause cancer in humans and 8 that probably cause cancer in\n humans.</p>\n \n <p>With approximately <strong>one non-smoker dying due to secondhand smoke\n exposure for every eight smokers dying</strong> of smoking-related disease it\n is no surprise that secondhand smoke has been designated a known human\n carcinogen (cancer-causing agent). Further, <strong>about half of regular\n smokers will die of a smoking-related disease</strong> and have a <strong>reduced life\n expectancy of about 13 to 16 years</strong> as compared with non- smokers.</p>\n \n <p><em>Source: <a href=\"http://www.health.gov.au/internet/quitnow/publishing.nsf/Content/1F9BA81210676CF8CA257A0D001F122C/$File/toxic.pdf\" rel=\"nofollow noreferrer\">Australian Department for Health</a>, Emphasis Mine</em></p>\n</blockquote>\n\n<p><strong>Risk of Heart Diseases and Strokes</strong></p>\n\n<blockquote>\n <p>If you smoke, your chance of dying from a heart attack is <strong>2 to 3 times\n greater</strong> than that of a person who does not smoke. About <strong>1 out of 4\n heart attacks is believed to be directly related to smoking</strong>. Smoking\n is a much more important risk factor for a heart attack than high\n cholesterol, obesity, high blood pressure, or stress.\n A person who smokes is twice as likely to die from a stroke as a person who does not smoke. </p>\n \n <p><em>Source: <a href=\"http://www.webmd.com/smoking-cessation/tc/smoking-heart-attack-and-stroke-risks-topic-overview\" rel=\"nofollow noreferrer\">WebMD</a>, Emphasis Mine</em></p>\n</blockquote>\n\n<hr>\n\n<h2>If you have children</h2>\n\n<p>Second hand smoking is especially damaging to children:</p>\n\n<blockquote>\n <p>Every day millions of children in the UK are exposed to secondhand\n smoke, which puts them at <strong>increased risk of lung disease, meningitis\n and cot death</strong>. Treatment, hospital and GP visits for secondhand smoke\n related illnesses cost the NHS more than £23.6 million each year.</p>\n \n <p><em>Source: <a href=\"https://www.gov.uk/government/news/childrens-health-up-in-smoke\" rel=\"nofollow noreferrer\">gov.uk</a>, Emphasis Mine</em></p>\n</blockquote>\n\n<p>Early exposure to chemicals is a lot more damaging than during adulthood.</p>\n\n<blockquote>\n <p>Passive smoking causes lasting damage to children's arteries,\n prematurely ageing their blood vessels by more than three years, say\n researchers.</p>\n \n <p><em>Source: <a href=\"http://www.bbc.com/news/health-26432111\" rel=\"nofollow noreferrer\">BBC.com</a></em></p>\n</blockquote>\n\n<p>This can lead to early heard attacks and other coronary diseases.</p>\n\n<blockquote>\n <p>Exposure of unborn children to tobacco smoke may also increase the\n risk of miscarriage, low birth weight and sudden infant death syndrome\n (SIDS), or ‘cot death’. There is strong evidence that the babies of\n mothers who smoke after birth have more lung diseases in their first\n year of life and have double the normal risk of serious airway\n infections.</p>\n \n <p><em>Source: <a href=\"https://www.health.gov.au/internet/main/publishing.nsf/Content/2C2DEB2D69E29B0DCA257BF0001E7410/$File/tobpass.pdf\" rel=\"nofollow noreferrer\">Gov.au</a></em></p>\n</blockquote>\n\n<p>If you have kids, you definitely should follow the advice below.</p>\n\n<h2>What you can do</h2>\n\n<blockquote>\n <p>You can protect yourself and your family from secondhand smoke by:</p>\n \n <ul>\n <li>Quitting smoking if you are not already a nonsmoker</li>\n <li>Not allowing anyone to smoke anywhere in or near your home</li>\n <li>Not allowing anyone to smoke in your car, even with the windows down</li>\n <li>Making sure your children’s day care center and schools are tobacco-free</li>\n <li>Seeking out restaurants and other places that do not allow smoking (if your state still allows smoking in public areas)</li>\n <li>Teaching your children to stay away from secondhand smoke. </li>\n <li>Being a good role model by not smoking or using any other type of tobacco.</li>\n </ul>\n \n <p><em>Source: <a href=\"https://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/general_facts/index.htm\" rel=\"nofollow noreferrer\">cdc.gov</a></em></p>\n</blockquote>\n", "score": 5 } ]
13,308
CC BY-SA 3.0
Is 2nd hand smoking worse than 1st hand smoking
[ "smoking", "second-hand-smoke" ]
<p>I have heard many things about smoking and a main issue as of one being that 2nd hand smoking is worse than 1st hand smoking itself? <strong>(I do not smoke I am just around someone who does smoke)</strong></p> <p>Is this rumor true? If <em>so</em> why is this, and what should I do if I can smell it or if I am around them when they light the cigarette?</p>
7
https://medicalsciences.stackexchange.com/questions/13440/can-sleeping-near-a-wifi-router-harm-your-health
[ { "answer_id": 14404, "body": "<p>There has been an ongoing debate regarding health risks from the electromagnetic fields being emitted from WiFi routers. The constant radiation exposure is arguably dangerous at close distances and may contribute to serious health issues, especially with long-term “chronic” exposure.</p>\n\n<p>In 2011, the World Health Organization classified radiofrequency electromagnetic fields as “<a href=\"http://monographs.iarc.fr/ENG/Classification/index.php\" rel=\"nofollow noreferrer\">possibly carcinogenic to humans</a>” based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use. </p>\n\n<p>The potential for adverse health effects resulting from exposure to radiofrequency electromagnetic fields, such as those emitted by wireless communication devices, are detailed in a 2011 World Health Organization press release titled, '<a href=\"https://www.scribd.com/document/56730830/pr208-E\" rel=\"nofollow noreferrer\">IARC Classifies Radiofrequency Electromagnetic Fields as Possibly Carcinogenic to Humans</a>'.</p>\n\n<blockquote>\n <p>From May 24-31 2011, a Working Group of 31 scientists from 14 countries has been meeting at IARC in Lyon, France to assess the potential carcinogenic hazards from exposure to radiofrequency electromagnetic fields. These assessments will be published as Volume 102 of the IARC Monographs, which will be the fifth volume in this series to focus on physical agents, after Volume 55 (Solar Radiation), Volume 75 and Volume 78 on ionizing radiation (X-rays, gamma-rays, neutrons, radio-nuclides), and <a href=\"http://monographs.iarc.fr/ENG/Monographs/vol80/mono80.pdf\" rel=\"nofollow noreferrer\">Volume 80</a> on non-ionizing radiation (extremely low-frequency electromagnetic fields). </p>\n</blockquote>\n\n<p>The IARC Monograph Working Group discussed the possibility that these exposures\ncould induce long-term effects, in particular an increased risk for cancer. The\nexposure categories involving radiofrequency electromagnetic fields that were discussed and evaluated included:</p>\n\n<blockquote>\n <p>…occupational exposures to radar and microwaves; environmental exposures associated with transmission of signals for radio, television and wireless telecommunication; and personal exposures associated with the use of wireless telephones.</p>\n</blockquote>\n\n<p>International experts shared the complex task of tackling the <a href=\"http://monographs.iarc.fr/ENG/Preamble/currentb1exp0706.php\" rel=\"nofollow noreferrer\">exposure data</a>, <a href=\"http://monographs.iarc.fr/ENG/Preamble/currentb2studieshumans0706.php\" rel=\"nofollow noreferrer\">the studies of cancer in humans</a>, <a href=\"http://monographs.iarc.fr/ENG/Preamble/currentb3studiesanimals0706.php\" rel=\"nofollow noreferrer\">the studies of cancer in experimental animals</a>, and the <a href=\"http://monographs.iarc.fr/ENG/Preamble/currentb4studiesother0706.php\" rel=\"nofollow noreferrer\">mechanistic and other relevant data</a>.</p>\n\n<blockquote>\n <p><strong>Results</strong></p>\n \n <p>The evidence was reviewed critically, and overall evaluated as being limited* among users of wireless telephones for glioma and acoustic neuroma, and inadequate** to draw conclusions for other types of cancers. The evidence from the occupational and environmental exposures mentioned above was similarly judged inadequate. The Working Group did not quantitate the risk; however, <strong>one study of past cell phone use (up to the year 2004), showed a 40% increased risk for gliomas in the highest category of heavy users (reported average: 30 minutes per day over a 10‐year period)</strong></p>\n \n <blockquote>\n <p>*'Limited evidence of carcinogenicity': A positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered by the Working Group to be credible, but chance, bias or confounding could not be ruled out with reasonable confidence.</p>\n \n <p>**'Inadequate evidence of carcinogenicity': The available studies are of insufficient quality, consistency or statistical power to permit a conclusion regarding the presence or absence of a causal association between exposure and cancer, or no data on cancer in humans are available. </p>\n </blockquote>\n</blockquote>\n\n<p>Dr. Jonathan Same (University of Southern California, USA) and overall Chairman of the Working Group, suggested that</p>\n\n<blockquote>\n <p>“…the evidence, while still accumulating, is strong enough to support a conclusion... The conclusion means that <strong>there could be some risk</strong>, and therefore we need to keep a close watch for a link between cell phones and cancer risk.”</p>\n</blockquote>\n\n<p>The IARC Director, Christopher Wild added,</p>\n\n<blockquote>\n <p>”Given the potential consequences for public health of this classification and findings, it is important that additional research be conducted into the long term, heavy use of mobile phones. Pending the availability of such information, <strong>it is important to take pragmatic measures to reduce exposure such as hands-free devices or texting</strong>”</p>\n</blockquote>\n\n<p>Several scientific articles resulting from the <a href=\"http://www.iarc.fr/en/media-centre/pr/2010/pdfs/pr200_E.pdf\" rel=\"nofollow noreferrer\">Interphone study</a> were made available to the working group and were included in the evaluation. </p>\n\n<p>One of the scientific articles, ’<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/21862434\" rel=\"nofollow noreferrer\">Acoustic neuroma risk in relation to mobile telephone use: results of the INTERPHONE international case-control study.</a>’ determined that</p>\n\n<blockquote>\n <p><strong>There was no increase in risk of acoustic neuroma with ever regular use of a mobile phone or for users who began regular use 10 years or more before the reference date.</strong> Elevated odds ratios observed at the highest level of cumulative call time could be due to chance, reporting bias or a causal effect. As acoustic neuroma is usually a slowly growing tumour, the interval between introduction of mobile phones and occurrence of the tumour might have been too short to observe an effect, if there is one.</p>\n</blockquote>\n\n<p>A second scientific article also included in the evaluation, ‘<a href=\"http://oem.bmj.com/content/68/9/686\" rel=\"nofollow noreferrer\">Estimation of RF energy absorbed in the brain from mobile phones in the Interphone Study</a>,’ explained</p>\n\n<blockquote>\n <p>While amount and duration of use are important determinants of RF dose in the brain, their <strong>impact can be substantially modified by communication system, frequency band and location in the brain</strong>. It is important to take these into account in analyses of risk of brain tumors from RF exposure from mobile phones.</p>\n</blockquote>\n\n<p>The Federal Communications Commission (FCC) issued a guide on <a href=\"https://www.fcc.gov/consumers/guides/wireless-devices-and-health-concerns\" rel=\"nofollow noreferrer\">Wireless Devices and Health Concerns</a> addresses the topic of RF exposure. </p>\n\n<blockquote>\n <p>...the Federal Communications Commission, federal health and safety agencies such as the Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA) have been actively involved in monitoring and investigating issues related to RF exposure. For example, the FDA has issued guidelines for safe RF emission levels from microwave ovens, and it continues to monitor exposure issues related to the use of certain RF devices such as cellular telephones. NIOSH conducts investigations and health hazard assessments related to occupational RF exposure.</p>\n \n <p>Federal, state and local government agencies and other organizations have generally relied on RF exposure standards developed by expert non-government organizations such as the Institute of Electrical and Electronics Engineers (IEEE) and the National Council on Radiation Protection and Measurements (NCRP). </p>\n \n <p>Since 1996, the FCC has required that <strong>all wireless communications devices sold in the United States meet its minimum guidelines for safe human exposure to radiofrequency (RF) energy</strong>. </p>\n</blockquote>\n\n<p>The FCC’s guidelines and rules regarding RF exposure </p>\n\n<blockquote>\n <p>...are based upon standards developed by IEEE and NCRP and input from other federal agencies... </p>\n</blockquote>\n\n<p>These guidelines specify exposure limits for hand-held wireless devices determined by the <strong>Specific Absorption Rate (SAR)</strong>. </p>\n\n<blockquote>\n <p>The SAR is a measure of the rate that RF energy is absorbed by the body. <strong>For exposure to RF energy from wireless devices, the allowable FCC SAR limit is 1.6 watts per kilogram (W/kg), as averaged over one gram of tissue</strong>.</p>\n</blockquote>\n\n<p>As of 1996, the FCC has required that</p>\n\n<blockquote>\n <p>...<strong>all wireless devices sold in the US go through a formal FCC approval process to ensure that they do not exceed the maximum allowable SAR level when operating at the device’s highest possible power level.</strong></p>\n</blockquote>\n\n<p>Several US government agencies and international organizations work cooperatively to monitor research on the health effects of RF exposure.</p>\n\n<blockquote>\n <p>According to the FDA and the World Health Organization (WHO), among other organizations, to date, <strong>the weight of scientific evidence has not effectively linked exposure to radio frequency energy from mobile devices with any known health problems</strong>.</p>\n</blockquote>\n\n<p>Some health and safety interest groups have interpreted certain reports to suggest that wireless device use may be linked to cancer and other illnesses, posing potentially greater risks for children than adults. </p>\n\n<blockquote>\n <p>While these assertions have gained increased public attention, currently <strong>no scientific evidence establishes a causal link between wireless device use and cancer or other illnesses</strong>. </p>\n</blockquote>\n\n<p>Although no scientific evidence currently establishes a direct link between wireless device use and cancer (or other illnesses), some consumers are skeptical of the science and analysis that underlies the FCC’s RF exposure guidelines. Thus, some parties recommend taking precautionary measures to further reduce exposure to RF energy. </p>\n\n<p>The FCC does not endorse the need for these practices, but provides information on steps you can take to reduce your exposure to RF energy from cell phones. For example,</p>\n\n<blockquote>\n <p>...<strong>wireless devices only emit RF energy when you are using them and, the closer the device is to you, the more energy you will absorb</strong>.</p>\n</blockquote>\n\n<p>Some of the FCC's suggested measures to reduce RF exposure include the following:</p>\n\n<blockquote>\n <ul><li>Use a speakerphone, earpiece or headset to reduce proximity to the head (and thus exposure). While wired earpieces may conduct some energy to the head and wireless earpieces also emit a small amount of RF energy, both wired and wireless earpieces remove the greatest source of RF energy (the cell phone) from proximity to the head and thus can greatly reduce total exposure to the head.</li><li><b>Increase the distance between wireless devices and your body.</b></li><li>Consider texting rather than talking - but don’t text while you are driving.</li></ul>\n</blockquote>\n\n<p>Although potentially misleading, some parties recommend considering reported SAR values of wireless devices.</p>\n\n<blockquote>\n <p>First, the actual <strong>SAR varies considerably depending upon the conditions of use</strong>. The SAR value used for FCC approval does not account for the multitude of measurements taken during the testing. Moreover, <strong>cell phones constantly vary their power to operate at the minimum power necessary for communications</strong>; <strong>operation at maximum power occurs infrequently</strong>. </p>\n \n <p>Second, <strong>the reported highest SAR values of wireless devices do not necessarily indicate that a user is exposed to more or less RF energy from one cell phone than from another during normal use</strong> </p>\n \n <blockquote>\n <p>For additional information, see <a href=\"https://www.fcc.gov/consumers/guides/specific-absorption-rate-sar-cell-phones-what-it-means-you\" rel=\"nofollow noreferrer\">SAR and cell phones</a>. </p>\n </blockquote>\n \n <p>Third, <strong>the variation in SAR from one mobile device to the next is relatively small compared to the reduction that can be achieved by the measures described above</strong>. Consumers should remember that <strong>all wireless devices are certified to meet the FCC maximum SAR standards, which incorporate a considerable safety margin.</strong> </p>\n \n <blockquote>\n <p>For additional information, see <a href=\"https://www.fcc.gov/general/specific-absorption-rate-sar-cellular-telephones\" rel=\"nofollow noreferrer\">maximum SAR value for each phone</a>.</p>\n </blockquote>\n</blockquote>\n\n<p>Some studies have also reported that wireless devices might interfere with implanted cardiac pacemakers </p>\n\n<blockquote>\n <p>...if used within <strong>eight inches</strong> of the pacemaker. </p>\n</blockquote>\n\n<p>Although several studies claim health risks associated with wireless and EMF radiation, there is still much work to be done before definitive statements about EMF safety can be made. Because these health risks are of concern to you, it may be advisable to take precautionary measures by placing your router at an appropriate distance from your body, especially while sleeping. However, it is best to discuss any health-related questions or concerns with your primary care physician or specialist. </p>\n\n<p>As a side note - you may also want to review the specs on the <a href=\"https://www.asus.com/us/Networking/RT-AC5300/specifications/\" rel=\"nofollow noreferrer\">Asus RT-AC5300 router</a> listed on the Asus website and request additional product documentation from the company to review with your primary care physician or specialist.</p>\n\n<hr />\n\n<p>Supplemental information and resources: </p>\n\n<p><a href=\"http://transition.fcc.gov/cgb/consumerfacts/mobilephone.pdf\" rel=\"nofollow noreferrer\">Wireless Devices and Health Concerns Guide</a></p>\n\n<p><a href=\"https://www.fcc.gov/general/radio-frequency-safety-0\" rel=\"nofollow noreferrer\">Radio Frequency Safety</a></p>\n\n<p><a href=\"https://www.youtube.com/watch?v=PqCDrHXgtd0\" rel=\"nofollow noreferrer\">CNN's Dr. Sanjay Gupta Explains: Cell phones and radiation</a></p>\n\n<p><a href=\"https://www.youtube.com/watch?v=v7wCeuSqm34\" rel=\"nofollow noreferrer\">Cell Phone Radiation Safety Tips With Dr Sanjay Gupta on Anderson Cooper 360</a></p>\n", "score": 5 } ]
13,440
CC BY-SA 3.0
can sleeping near a wifi router harm your health?
[ "risks" ]
<p>i would like to ask if is it possible to get brain tumors or any health risk if i sleep beside a "powerful" WiFi router(eg. Asus RT-AC5300)?</p> <p>Googled around and found that some people say it's totally fine and some are saying to not sleep beside it...</p>
7
https://medicalsciences.stackexchange.com/questions/13492/does-the-use-of-sunscreen-inhibit-vitamin-d-production
[ { "answer_id": 13493, "body": "<p>This has been a <a href=\"https://mobile.nytimes.com/2009/02/17/health/17real.html?referer=\" rel=\"noreferrer\">controversial question for many years</a>. The current evidence suggests that sunscreen <strong>does block a part of Vitamin D production, but with negligible amounts</strong>.</p>\n\n<blockquote>\n <p>Studies have found that by blocking ultraviolet rays, sunscreen limits\n the vitamin D we produce. But the question is to what extent.</p>\n \n <p>A few studies have concluded that the effect is significant — a\n reduction as great as tenfold. But more recent, <strong>randomized studies\n that followed people for months and in some cases years suggest that\n the effect is negligible.</strong> While sunscreen does hamper vitamin D\n production, these studies say, it is not enough to cause a deficiency.<br>\n <em>[...]</em><br>\n Dr. Lim added that <strong>rather than cutting back on sunscreen</strong>, people\n concerned about vitamin D should <strong>consume more foods rich in vitamin D</strong>,\n like salmon, milk and orange juice. </p>\n \n <p><em>Source: <a href=\"https://mobile.nytimes.com/2009/02/17/health/17real.html?referer=\" rel=\"noreferrer\">New York Times Article</a>, Emphasis Mine</em></p>\n</blockquote>\n\n<hr>\n\n<h2>Studies cited in the article</h2>\n\n<ul>\n<li><p>Matusoka LY et al. <em>Chronic sunscreen use decreases circulating concentrations of 25-hydroxyvitamin D. A preliminary study.</em> <a href=\"https://www.ncbi.nlm.nih.gov/m/pubmed/3190255/\" rel=\"noreferrer\">PubMed link</a></p></li>\n<li><p>Marks R et al. <em>The effect of regular sunscreen use on vitamin D levels in an Australian population. Results of a randomized controlled trial.</em> <a href=\"https://www.ncbi.nlm.nih.gov/m/pubmed/7726582/\" rel=\"noreferrer\">PubMed link</a></p></li>\n<li><p>Farrerons J et al. <em>Clinically prescribed sunscreen (sun protection factor 15) does not decrease serum vitamin D concentration sufficiently either to induce changes in parathyroid function or in metabolic markers.</em> <a href=\"https://www.ncbi.nlm.nih.gov/m/pubmed/9767286/\" rel=\"noreferrer\">PubMed link</a></p></li>\n</ul>\n", "score": 5 }, { "answer_id": 13523, "body": "<p>Vitamin D is produced in the skin. There are two subtypes of UV radiation: UVA and UVB. UVA is primarily responsible for photoaging, and UVB for the superficial burning that results from sun exposure (2).</p>\n\n<p>UVB electromagnetic radiation converts 7-dehydrocholestrol to pre-vitamin D3, which is then converted into Vitamin D3 (1). Sunscreens with an SPF rating absorb or reflect (depending on the filters used) UVB light (2). Without UVB light, 7-dehydrocholestrol cannot be converted into pre-vitamin D. It may also be of interest to note that glass blocks UVB (but not UVA radiation) and thus has a similar effect on Vitamin D production (1). </p>\n\n<p>In reality, however, people rarely apply sunscreen well enough so that Vitamin D production completely ceases (3).</p>\n\n<p>In short, yes sunscreen does inhibit the production of Vitamin D, although in most cases not to such an extent that Vitamin D deficiency becomes a concern. </p>\n\n<p><strong>References</strong></p>\n\n<ol>\n<li><a href=\"https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/\" rel=\"nofollow noreferrer\">https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/</a></li>\n<li><a href=\"http://www.skincancer.org/prevention/uva-and-uvb\" rel=\"nofollow noreferrer\">http://www.skincancer.org/prevention/uva-and-uvb</a></li>\n<li><a href=\"https://www.health.harvard.edu/staying-healthy/6-things-you-should-know-about-vitamin-d\" rel=\"nofollow noreferrer\">https://www.health.harvard.edu/staying-healthy/6-things-you-should-know-about-vitamin-d</a></li>\n</ol>\n", "score": 4 }, { "answer_id": 24144, "body": "<p>In addition to the other answers:</p>\n<blockquote>\n<p>[C]linical studies have never found that everyday sunscreen use leads to\nvitamin D insufficiency. In fact, the prevailing studies show that\npeople who use sunscreen daily can maintain their vitamin D levels.</p>\n<p>One of the explanations for this may be that no matter how much\nsunscreen you use or how high the SPF, some of the sun’s UV rays reach\nyour skin. An SPF 15 sunscreen filters out 93 percent of UVB rays, SPF\n30 keeps out 97 percent, and SPF 50 filters out 98 percent. This\nleaves anywhere from 2 to 7 percent of solar UVB reaching your skin,\neven with high-SPF sunscreens. And that’s if you use them perfectly.</p>\n</blockquote>\n<p><a href=\"https://www.skincancer.org/blog/sun-protection-and-vitamin-d/\" rel=\"nofollow noreferrer\">Sun Protection and Vitamin D By Skin Cancer Foundation</a></p>\n<blockquote>\n<p>There are claims that one needs to get a certain amount of sun\nexposure every day in order to produce enough vitamin D to be healthy.\nIt’s just not true</p>\n<p><em>David J. Leffell, MD, Yale Medicine dermatologist and chief of\nDermatologic Surgery</em></p>\n</blockquote>\n<p><a href=\"https://www.yalemedicine.org/stories/vitamin-d-myths-debunked/\" rel=\"nofollow noreferrer\">Vitamin D Myths 'D'-bunked - Yale Medicine</a></p>\n", "score": 2 } ]
13,492
CC BY-SA 4.0
Does the use of sunscreen inhibit Vitamin D production?
[ "vitamin-d", "uv-rays", "sun-exposure", "sunlight", "sunscreen-sunblock" ]
<p>Vitamin D is produced in the skin when exposed to sunlight. Therefore, when using sunscreen on the skin, is Vitamin D production inhibited?</p>
7
https://medicalsciences.stackexchange.com/questions/13682/fat-vs-obesity
[ { "answer_id": 15584, "body": "<p>Fat is a lay non medical term. Obesity is defined as a BMI > 30 in adults</p>\n\n<p><strong>What are overweight and obesity?</strong></p>\n\n<p>Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health.</p>\n\n<p>Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity in adults. It is defined as a person's weight in kilograms divided by the square of his height in meters (kg/m2).</p>\n\n<p><strong>Adults</strong></p>\n\n<p>For adults, WHO defines overweight and obesity as follows:</p>\n\n<p>overweight is a BMI greater than or equal to 25; and\nobesity is a BMI greater than or equal to 30.</p>\n\n<p><a href=\"http://www.who.int/mediacentre/factsheets/fs311/en/\" rel=\"nofollow noreferrer\">http://www.who.int/mediacentre/factsheets/fs311/en/</a></p>\n\n<p><strong>Health Risks</strong></p>\n\n<p>Are related to the degree of being obese.</p>\n\n<p>It makes you more likely to have conditions including:</p>\n\n<ol>\n<li>Heart disease and stroke. </li>\n<li>High blood pressure. </li>\n<li>Diabetes. </li>\n<li>Some cancers. Increased rate of relapse from eg. breast cancer</li>\n<li>Gallbladder disease and gallstones. </li>\n<li>Osteoarthritis. </li>\n<li>Gout. </li>\n<li>Breathing problems, such as sleep apnea (when a person stops breathing for short episodes during sleep) and asthma.</li>\n<li>Psoriasis</li>\n<li>Poor response to drugs for arthritis</li>\n</ol>\n\n<p><a href=\"https://www.webmd.com/diet/obesity/obesity-health-risks\" rel=\"nofollow noreferrer\">https://www.webmd.com/diet/obesity/obesity-health-risks</a></p>\n", "score": 4 } ]
13,682
CC BY-SA 3.0
Fat vs. Obesity
[ "obesity" ]
<p>What is the difference between being fat and obese?</p> <p>Is being fat healthy? Some parents are very happy to have kids who are fat. They say fat is healthy, but being overweight isn't. Why would this be the case? What adverse health effects are there when one is obese (or fat, respectively).</p>
7
https://medicalsciences.stackexchange.com/questions/13712/how-do-i-evaluate-health-benefits-and-health-advertisements-of-products
[ { "answer_id": 13719, "body": "<p>Educate yourself! That means reading up. From reliable sources. Most of the information on the internet is mere statements on sites that present health relevant info as easy and simple. But in reality most often answers to your question are not so easy and not so simple. </p>\n\n<p>While certain companies and sometimes even mother nature might not subscribe to the following principle, at least you should treat yourself like a good doctor promised to do: first, do no harm! That means when looking for information you should always keep a very keen eye on on the cost/benefit relation that the information you find will hopefully enable you to estimate. Look for the possible side effects.</p>\n\n<h2>Using information about the product in general</h2>\n\n<ol>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/\" rel=\"nofollow noreferrer\">PubMed</a> is a free archive of medical articles regarding almost anything. Enter the product name (or the active agent) and see what comes up. \n\n<ul>\n<li>If you have questions regarding a specific article, <strong>feel free to ask here.</strong></li>\n<li>If you are looking for the whole article source, and not just the abstract, copy the article name and paste it into a Google search field, using parenthesis (\"Abstract Title Goes Here\"). This way, Google will only show you search results for exactly this combination of words. Check through a few links at the top to see whether one of the archives has the full text without a text wall. If you still do not find the full text, consult your university library (if any) or talk to your librarian in your public library. Otherwise, <strong>ask on our main chatroom, <a href=\"https://chat.stackexchange.com/rooms/22477/the-waiting-room\">The Waiting Room</a></strong>, and someone might be able to help you out.</li>\n</ul></li>\n<li>Visit the website of the <a href=\"https://www.fda.gov\" rel=\"nofollow noreferrer\">FDA</a> and search for the name of your product.\n\n<ul>\n<li>If negative or positive health effects are listed and you do not understand why the product in question does have this effect, <strong>feel free to ask here</strong>. </li>\n</ul></li>\n<li>Visit <a href=\"http://www.mayoclinic.org\" rel=\"nofollow noreferrer\">MayoClinic</a> and see if anything pops up. \n\n<ul>\n<li>If you have questions regarding the Mayo Clinic Article, <strong>feel free to ask here.</strong></li>\n<li>Do go to the bottom of the article and have a read through the sources MayoClinic provides. </li>\n</ul></li>\n<li><p>Try googling the product name directly (using parenthesis). </p>\n\n<ul>\n<li>If you are uncertain, whether such the search results come from reliable resources, <strong>ask on our main chatroom, The Waiting Room</strong>.</li>\n<li>If you do not understand why the product has the effect you were able to find, <strong>feel free to ask here</strong>.</li>\n</ul></li>\n<li><p>For cosmetics and their ingredients you might consult databases like <a href=\"http://codecheck.info\" rel=\"nofollow noreferrer\">CodeCheck</a> or <a href=\"https://www.ewg.org/skindeep/\" rel=\"nofollow noreferrer\">SkinDeep</a>.</p></li>\n</ol>\n\n<h2>Using information about the ingredients</h2>\n\n<ol>\n<li>Research all molecules and ingredients of the product at <a href=\"https://pubchem.ncbi.nlm.nih.gov\" rel=\"nofollow noreferrer\">PubChem</a>. \n\n<ul>\n<li>If you do not understand what a chemical compound is, or how it interacts with other chemicals, <strong>feel free to visit <a href=\"https://chemistry.stackexchange.com/\">Chemistry.SE</a> and ask there</strong>.</li>\n<li>If you have a question about the interaction of said chemical with your body, visit the sections \"Drug and Medication Information\", \"Pharmacology and Biochemistry\" and \"Biomolecular Interactions and Pathways\". If you do not understand information there, <strong>decide whether you should ask at Chemistry.SE or here</strong></li>\n</ul></li>\n</ol>\n", "score": 6 } ]
13,712
CC BY-SA 3.0
How do I evaluate health benefits and health advertisements of products?
[ "health-education", "public-health" ]
<p>In general, what steps could a layperson take to ensure the product they consume is healthy for them, or to get to know the adverse health effects of said product.</p> <p>A good answer would talk about where to find medical studies regarding consumption of products, how to evaluate the reliability of those studies, and what other easily accessible resources one should consult.</p>
7
https://medicalsciences.stackexchange.com/questions/13730/pregnancy-and-flying
[ { "answer_id": 13733, "body": "<p>Specific to the health of the baby, no, you should not have any concerns over a single flight, or even over an occasional flight. From the American Congress of Obstetricians and Gynecologists is this <a href=\"https://www.acog.org/Resources-And-Publications/Committee-Opinions/Committee-on-Obstetric-Practice/Air-Travel-During-Pregnancy\" rel=\"noreferrer\">helpful guide to air travel during pregnancy</a>, where they specifically discuss a few risks which I will summarize below. All of this assumes a healthy pregnancy, and before term.</p>\n<p>The abstract summarizes it well:</p>\n<blockquote>\n<p>In the absence of obstetric or medical complications, pregnant women can observe the same precautions for air travel as the general population and can fly safely. Pregnant women should be instructed to continuously use their seat belts while seated, as should all air travelers. Pregnant air travelers may take precautions to ease in-flight discomfort and, although no hard evidence exists, preventive measures can be used to minimize risks of venous thrombosis. For most air travelers, the risks to the fetus from exposure to cosmic radiation are negligible. For pregnant aircrew members and other frequent flyers, this exposure may be higher. Information is available from the FAA to estimate this exposure.</p>\n</blockquote>\n<p>My summary of the specific risks from the longer paper:</p>\n<ol>\n<li><p>Environmental conditions</p>\n<p>The pressurized environment of the aircraft can lead to some changes in the mother's blood pressure and heart rate; there is currently no evidence this is likely to cause an issue with a developing fetus, but you can take preventative measures such as wearing support stockings, walking around periodically, and drinking sufficient water.</p>\n</li>\n<li><p>Turbulence</p>\n<p>Turbulence can cause the expectant mother to fall and be injured (which could in theory do harm to the fetus), so when possible sit down with your seatbelt fastened.</p>\n</li>\n<li><p>Cosmic radiation, etc.</p>\n<p>An occasional flight will not cause you to receive more ionizing radiation than the generally accepted safe level; however, many flights could put you at risk of surpassing that level. The specifics, and a link to determine her specific exposure:</p>\n</li>\n</ol>\n<blockquote>\n<p>Available information suggests that noise, vibration, and cosmic radiation present a negligible risk for the occasional pregnant air traveler (6, 7). Both the National Council on Radiation Protection and Measurements and the International Commission on Radiological Protection recommend a maximum annual radiation exposure limit of 1 millisievert (mSv) (100 rem) for members of the general public and 1 mSv over the course of a 40-week pregnancy (7). Even the longest available intercontinental flights will expose passengers to no more than 15% of this limit (7); therefore, it is unlikely that the occasional traveler will exceed current exposure limits during pregnancy. However, aircrew or frequent flyers may exceed these limits. The Federal Aviation Administration and the International Commission on Radiological Protection consider aircrew to be occupationally exposed to ionizing radiation and recommend that they be informed about radiation exposure and health risks (8, 9). A tool to estimate an individual exposure to cosmic radiation from a specific flight is available from the Federal Aviation Administration on its web site (<a href=\"http://jag.cami.jccbi.gov/cariprofile.asp\" rel=\"noreferrer\">http://jag.cami.jccbi.gov/cariprofile.asp</a>).</p>\n</blockquote>\n<p>So - no, your partner did not put the fetus at particular risk by flying while pregnant; however, if she is likely to fly many times during the pregnancy (such as, if she works in sales and flies on a weekly basis), she should talk to her obstetrician and ask them whether the particular flight frequency and duration is safe throughout the pregnancy.</p>\n", "score": 11 }, { "answer_id": 13732, "body": "<p>Don't worry! You should be totally fine. It sounds like flying early in pregnancy does not have any negative side affects.</p>\n\n<p>From the <a href=\"http://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/expert-answers/air-travel-during-pregnancy/faq-20058087\" rel=\"noreferrer\">Mayo Clinic</a>:</p>\n\n<blockquote>\n <p>Generally, commercial air travel before week 36 of pregnancy is\n considered safe for women who have healthy pregnancies</p>\n</blockquote>\n\n<p>If you wanted more links:</p>\n\n<p><a href=\"http://www.nhs.uk/chq/Pages/927.aspx?CategoryID=54\" rel=\"noreferrer\">http://www.nhs.uk/chq/Pages/927.aspx?CategoryID=54</a></p>\n\n<p><a href=\"http://www.webmd.com/baby/taking-to-the-skies-pregnant-and-safe#1\" rel=\"noreferrer\">http://www.webmd.com/baby/taking-to-the-skies-pregnant-and-safe#1</a></p>\n\n<p>Also Congratulations! </p>\n", "score": 7 } ]
13,730
Pregnancy and flying
[ "obstetrics" ]
<p>I've heard that flying can harm a developing baby when the mother is pregnant.</p> <p>What happened to my partner is that she missed her period and took a flight after being one and a half months pregnant. Only after the flight did we meet and take a pregnancy test which resulted positive. </p> <p>My partner did not know flying could harm the baby. What is the truth about possible impacts that flying can have on your baby and what kind of damage can result? Am I getting too worried or do I have reasons to be worried?</p>
7
https://medicalsciences.stackexchange.com/questions/13775/differences-between-md-vs-do-regarding-computational-research
[ { "answer_id": 13788, "body": "<p>MDs and DOs are both physicians. Both learn at least a core medical curriculum, then take exams demonstrating that level of knowledge (USMLE vs COMLEX). Both can apply for residencies for any specialty, and they take the exact same specialty boards in order to practice medicine. Both can go into research or any other branch of medical science, with or without going through a residency.</p>\n\n<p>The core medical curriculum is offered in all. So I honestly feel that what you learn and your exposure to research is highly institution-dependent, and the differences between MD schools can even be greater than between MD and DO schools. (Except that <a href=\"http://medschool.ucla.edu/body.cfm?id=1158&amp;action=detail&amp;ref=1019\" rel=\"noreferrer\">OMT</a> is not offered in most MD schools to my knowledge.) There are some generalizations, like that DO schools tend to be more holistic in philosophy, but even that is institution-dependent.</p>\n\n<p>Unfortunately, historically, and even still in some circumstances/regions/fields, DOs have had a more uphill battle to reach the positions and recognition that they deserve in this MD-dominated medical field. But within the medical field, I feel that the vast majority of MDs and DOs today finally see each other as equal colleagues, as they should. </p>\n\n<p><em>Certainly</em> a doctor's skill as a clinician or researcher is more dependent on their individual learning, mentorship and experiences that they seek out than anything else!</p>\n\n<p>Which is probably the most important factor for someone going into research: what the affiliated UNIVERSITY is doing. What research can you be involved in during medical school? What can it offer you in strength of opportunities and mentorship? </p>\n\n<p>I would approach it by exploring the difference between SCHOOLS rather than degrees. Figure out who is doing what you want to do, and who offers the most opportunity to explore what you're interested in. Then apply accordingly. Also, I recommend contacting both an MD and a DO in a similar field of research and ask them for their perspective on their experience, and advice as someone coming into the field.</p>\n", "score": 4 } ]
13,775
CC BY-SA 3.0
Differences between MD vs DO regarding computational research?
[ "practice-of-medicine" ]
<p>I'm nearing graduation from university, at which point I'll have a degree in computer science (bioinformatics) with a minor in mathematics. My intention is to specialize in computational medical research, perhaps applying various A.I. techniques to studying/modeling medical data.</p> <p>My question is, <strong>is there an inherent difference between MD vs. DO regarding the ability to perform research?</strong> Are there more resources available for one more than the other? Does the industry, in general, promote/value research of DO more than MD? Other way around?</p> <p>Any insight is greatly appreciated, as I need to start thinking about MCAT and applying to programs. </p>
7
https://medicalsciences.stackexchange.com/questions/13800/hydrating-before-a-fast-day
[ { "answer_id": 13810, "body": "<p>OK, so this seems to be a 24 hour fast.</p>\n\n<p>Salt (sodium) and glycerol, after drinking water, prolong the time in which the water is excreted from the body, but they both work only for few hours. </p>\n\n<p>The idea of hyperhydration to delay dehydration sounds interesting for marathon runners (in order to avoid the need to drink during the race), but according to <a href=\"http://journals.lww.com/acsm-msse/Fulltext/2007/02000/Exercise_and_Fluid_Replacement.22.aspx\" rel=\"nofollow noreferrer\">American College of Sports Medicine</a>, only few hours after hyperhydration, you will likely lose the excessive water.</p>\n\n<blockquote>\n <p>Attempting to hyperhydrate with fluids that expand of the extra- and\n intracellular spaces (e.g., water and glycerol solutions) will greatly\n increase the risk of having to void during competition...</p>\n</blockquote>\n\n<p>Glycerol can also have side effects, such as diarrhea.</p>\n\n<p>I am not aware of any nutrient, supplement or food that would keep the water in your body in any meaningful manner in a 24-hour fasting scenario.</p>\n\n<p>The effect of fasting is that you <em>feel</em> the lack of benefit of food. The resulting hunger can then remind you of things, other than food, that are important for you. Resisting from food alone (while drinking water) can already have this effect. Hyperhydration before fasting would cancel the effect of resisting from water, so what's the point of this, anyway.</p>\n\n<p>Saying that, I am not promoting or suggesting anyone to resist from drinking water for any amount of time, because it could be potentially health- or even life-threatening.</p>\n\n<p>If one has to survive for 24 hours without water and food, the means to avoid dehydration can be:</p>\n\n<ul>\n<li>Keep yourself well hydrated before fasting.</li>\n<li>Avoid <a href=\"https://www.nap.edu/read/10925/chapter/6#133\" rel=\"nofollow noreferrer\">alcohol and caffeine</a> before fasting because they can promote the excretion of water through the urine.</li>\n<li>Avoid/limit anything what promotes sweating, such as exercise, exposure to sun and excessive clothing.</li>\n</ul>\n", "score": 6 } ]
13,800
CC BY-SA 3.0
Hydrating before a fast day
[ "nutrition", "fasting", "hydration" ]
<p>There are a few days a year in which certain religions fast. </p> <p>I was wondering if there's an evidence based approach for absorbing a lot of water before to help keep oneself hydrated. I was reading <a href="https://health.stackexchange.com/q/5429/11535">this question about the speed at which we should drink</a> whose answer was positioned towards rehydrating. <a href="http://www.aish.com/h/hh/yom-kippur/guide/Seven_Steps_to_an_Easy_Fast.html" rel="noreferrer">Other articles</a> recomends avoiding chocolate, tea, coffee and salt. I would have thought though that adding salt to your water while loading up for a fast day would help you absorb more of it because it will counteract some of the water (meaning it will say in you and not be excreted). </p> <p>How should one consume salt and water in the days leading up to a fast?</p>
7
https://medicalsciences.stackexchange.com/questions/13824/ct-scans-and-cancer-risk
[ { "answer_id": 13825, "body": "<p>Every procedure has to be weighed for potential costs and benefits. Cancer is a risk already present and might shorten a life, CT scans on the other hand are done to prolong a life.<br>\nThe <em>exact</em> risks (costs) for CT scans is unknown, especially the exact risks <em>for you</em>, since we only have statistical data to estimate that.</p>\n\n<p>Prior data forms the basis for this statistical risk assessment.\nFor example: <a href=\"http://www.sciencedirect.com/science/article/pii/S0140673612608150\" rel=\"noreferrer\">Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study:</a></p>\n\n<blockquote>\n <p>Although CT scans are very useful clinically, potential cancer risks exist from associated ionising radiation, in particular for children who are more radiosensitive than adults. We aimed to assess the excess risk of leukaemia and brain tumours after CT scans in a cohort of children and young adults. […]\n Use of CT scans in children to deliver cumulative doses of about 50 mGy might almost triple the risk of leukaemia and doses of about 60 mGy might triple the risk of brain cancer. Because these cancers are relatively rare, <strong><em>the cumulative absolute risks are small</em></strong>: in the 10 years after the first scan for patients younger than 10 years, one excess case of leukaemia and one excess case of brain tumour per 10 000 head CT scans is estimated to occur. Nevertheless, although clinical benefits should outweigh the small absolute risks, radiation doses from CT scans ought to be kept as low as possible and alternative procedures, which do not involve ionising radiation, should be considered if appropriate. (emphasis added)</p>\n</blockquote>\n\n<p>The technology and methods are constantly improved upon. Unnecessary scans should be avoided though. <a href=\"http://pubs.rsna.org/doi/abs/10.1148/radiol.2511081300\" rel=\"noreferrer\">Whole-Body PET/CT Scanning: Estimation of Radiation Dose and Cancer Risk:</a> </p>\n\n<blockquote>\n <p>Whole-body PET/CT scanning is accompanied by substantial radiation dose and cancer risk. Thus, examinations should be clinically justified, and measures should be taken to reduce the dose.</p>\n</blockquote>\n\n<p>But that does not mean you should deny any further scans. But make sure your doctors know about prior scans. Especially when changing doctors. Sometimes old scans are unknown to exist but just as useful.</p>\n\n<p>To visualise that you can not avoid all radiation and to put the doses you receive from scans in perspective, this looks very useful:</p>\n\n<p><a href=\"https://i.stack.imgur.com/75x40.png\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/75x40.png\" alt=\"https://xkcd.com/radiation/\"></a></p>\n\n<p>Do not take this chart as a reliable guide or definitive advice. But do a mathematical comparison of two figures: \"Chest CT scan\" and \"Maximum yearly dose permitted for US radiation workers.\" (The equivalent of 7 of these scans <em>in one year</em> would still be considered \"OK\" under these workplace regulations.)</p>\n\n<p>In more practical terms this might translate into something like \"How Much Do CT Scans Increase the Risk of Cancer?\":</p>\n\n<blockquote>\n <p><a href=\"https://www.scientificamerican.com/article/how-much-ct-scans-increase-risk-cancer/\" rel=\"noreferrer\">A 2009 study of medical centers in the San Francisco Bay Area also calculated an elevated risk: one extra case of cancer for every 400 to 2,000 routine chest CT exams.</a></p>\n</blockquote>\n\n<p>For a more detailed breakdown consult information like \"Computed Tomography (CT) Scans and Cancer\" from the National Cancer Institute:</p>\n\n<blockquote>\n <p><a href=\"https://www.cancer.gov/about-cancer/diagnosis-staging/ct-scans-fact-sheet\" rel=\"noreferrer\">It is commonly thought that the extra risk of any one person developing a fatal cancer from a typical CT procedure is about 1 in 2,000. In contrast, the lifetime risk of dying from cancer in the U.S. population is about 1 in 5.</a></p>\n</blockquote>\n", "score": 12 } ]
13,824
CC BY-SA 4.0
CT scans and cancer risk
[ "cancer", "risks", "ct-scans", "bioelectromagnetics" ]
<p>I've had maybe 5 or 6 CT scans over the course of my life, and I'm only 27. </p> <p>What risk do those CTs present to someone like me?</p>
7
https://medicalsciences.stackexchange.com/questions/13903/can-too-much-potassium-from-sports-drinks-be-dangerous-lethal
[ { "answer_id": 13906, "body": "<p>Sports drinks contain trivial amounts of potassium. For example, one US gallon of <a href=\"http://www.pepsicobeveragefacts.com/Home/Product?formula=33877&amp;form=RTD&amp;size=32\" rel=\"nofollow noreferrer\">Gatorade contains 480 mg of potassium</a>, which is roughly comparable to a single banana and much less than a sweet potato. The US RDA for potassium is <a href=\"https://www.webmd.com/a-to-z-guides/tc/potassium-content-of-fruits-vegetables-and-other-foods-topic-overview#1\" rel=\"nofollow noreferrer\">4700 mg per day</a>, so you could safely drink 10 gallons per day if you consumed nothing else. </p>\n\n<p>The dangers of potassium are vastly overstated, even by most medical professionals. If you have normal kidney function and you're not taking a small number of medications that cause potassium retention, it's actually extremely difficult to make yourself hyperkalemic by oral consumption. </p>\n", "score": 10 } ]
13,903
CC BY-SA 3.0
Can too much potassium from sports drinks be dangerous/lethal?
[ "heart", "potassium", "electrolytes" ]
<p>I have always been aware that sports drinks help you replace potassium lost from exercise. But I also know that too much potassium in your bloodstream is not a good thing and bad for your heart. So can drinking too many sports drinks be dangerous for you? What would happen if a person drank a gallon of a sports drink a day for a month? </p>
7
https://medicalsciences.stackexchange.com/questions/13960/does-cannabidiol-cbd-help-prevent-or-heal-a-tendinopathy
[ { "answer_id": 16632, "body": "<p>A quick look through the medical literature leads me to the conclusion that there is no evidence that CBD promotes healing of tendinopathy.</p>\n<p>The anti-arthritic effect in your referenced paper is based on an immune-mediated inflammatory response which is different to the mechanism of inflammation in traumatic tendinopathy.</p>\n<p><a href=\"https://doi.org/10.1371/journal.pone.0113161\" rel=\"nofollow noreferrer\">This paper</a> deals with a mechanical trauma and suggests that injury-related MRI signal and histological changes are reduced with injection of CBD in a mouse model. This was the most relevant paper I could find on your particular question.</p>\n<blockquote>\n<p>In summary our study revealed anti-degenerative effects of intradiscal microinjection of CBD 120 nmol. CBD represents one of the most promising candidates present in the Cannabis sativa plant for clinical use due to its remarkable lack of cognitive or psychotomimetic actions. It has been already approved in several countries for the treatment of neuropathic pain. Although further research is necessary to clarify the mechanisms involved in CBD effects, the present results suggest the possibility of its use for disc degeneration treatment.</p>\n<p><sup>Source: Silveira, J. W., Issy, A. C., Castania, V. A. et al. (2014). <strong><a href=\"https://doi.org/10.1371/journal.pone.0113161\" rel=\"nofollow noreferrer\">Protective Effects of Cannabidiol on Lesion-Induced Intervertebral Disc Degeneration.</a></strong> PLoS ONE, 9(12).</sup></p>\n</blockquote>\n<p>In short: there is no good evidence for wound healing and CBD in humans currently. <em>In vivo</em> and mouse models show an anti-inflammatory effect, but this is not the same as &quot;promoting healing&quot;.</p>\n", "score": 5 } ]
13,960
CC BY-SA 3.0
Does cannabidiol (CBD) help prevent or heal a tendinopathy?
[ "tendinopathy" ]
<p>I read on <a href="http://mmajunkie.com/2016/08/with-vape-pen-in-hand-ufc-202s-nate-diaz-explains-the-benefits-of-cannabidiol-oil" rel="noreferrer">http://mmajunkie.com/2016/08/with-vape-pen-in-hand-ufc-202s-nate-diaz-explains-the-benefits-of-cannabidiol-oil</a></p> <blockquote> <p>“It’s CBD [cannabidiol],” Diaz said. “It helps with the healing process and inflammation and things like that, so you want to get these for before or after the fights, in training. It’ll make your life a better place.”</p> </blockquote> <p>I found a research paper (1) regarding the use of <a href="https://en.wikipedia.org/wiki/Cannabidiol" rel="noreferrer">cannabidiol</a> (a nonpsychoactive cannabis constituent with <a href="https://en.wikipedia.org/wiki/Cannabidiol" rel="noreferrer">no documented side effect</a>) for collagen-induced arthritis (CIA): </p> <blockquote> <p>Taken together, these data show that CBD [cannabidiol], through its combined immunosuppressive and anti-inflammatory actions, has a potent anti-arthritic effect in CIA [collagen-induced arthritis].</p> </blockquote> <p>but it is quite old (2000), and doesn't address tendinopathies.</p> <p>Does cannabidiol (CBD) help prevent or heal a tendinopathy? If so, what's the best modality (e.g., injections, patches, smoking)?</p> <hr> <ul> <li>(1) Malfait, Anne-Marie, R. Gallily, P. F. Sumariwalla, A. S. Malik, E. Andreakos, R. Mechoulam, and M. Feldmann. "The nonpsychoactive cannabis constituent cannabidiol is an oral anti-arthritic therapeutic in murine collagen-induced arthritis." Proceedings of the National Academy of Sciences 97, no. 17 (2000): 9561-9566. <a href="https://scholar.google.com/scholar?cluster=505227943814940929&amp;hl=en&amp;as_sdt=0,22" rel="noreferrer">https://scholar.google.com/scholar?cluster=505227943814940929&amp;hl=en&amp;as_sdt=0,22</a> ; <a href="http://www.pnas.org/content/97/17/9561.full" rel="noreferrer">http://www.pnas.org/content/97/17/9561.full</a> ; <a href="http://sci-hub.cc/10.1073/pnas.160105897" rel="noreferrer">http://sci-hub.cc/10.1073/pnas.160105897</a></li> </ul>
7
https://medicalsciences.stackexchange.com/questions/14106/ulcerative-colitis-disease-activity
[ { "answer_id": 16631, "body": "<p><strong>N.b. My institution does not have access to this journal and the upload you made has since been deleted</strong></p>\n\n<p>There are a number of ways of scoring the severity of ulcerative colitis on endoscopy; there are at least 8 in clinical use. They all take into account visible features such as vascular patterning, presence of ulcerations, the friability of the mucosal tissue and the presence of mucopurelent exudate.</p>\n\n<p>A nice review of available activity scores in UC is available here:<br>\n<a href=\"https://academic.oup.com/gastro/article/2/3/161/2910194\" rel=\"nofollow noreferrer\">Elizabeth R. Paine\"Colonoscopic evaluation in ulcerative colitis\", Gastroenterology Report, Volume 2, Issue 3, 1 August 2014</a>, Pages 161–168, <a href=\"https://doi.org/10.1093/gastro/gou028\" rel=\"nofollow noreferrer\">https://doi.org/10.1093/gastro/gou028</a></p>\n\n<p>Unfortunately, without access to the methods section of this paper it isn't possible for me to say which score and at what threshold they defined \"active\" and \"inactive\".</p>\n\n<p>The aim of UC treatment is to induce a remission state, usually through the use of high-dose steroids, then maintain this state with other drugs such as mesalazine. However, the hallmark of UC is \"flaring\" of the disease where symptoms worsen markedly.</p>\n\n<p>I couldn't find much on the frequency of flares but his paper suggests that ~50% patients self-report a flare once a month or more frequently:<br>\n<a href=\"https://www.clinicaltherapeutics.com/action/showCitFormats?pii=S0149-2918%2810%2900061-5&amp;doi=10.1016%2Fj.clinthera.2010.02.010\" rel=\"nofollow noreferrer\">Susan C. Bolge et al.: \"Self-reported frequency and severity of disease flares, disease perception, and flare treatments in patients with ulcerative colitis: Results of a national internet-based survey\", Clinical Therapeutics, Volume 32, Issue 2, 238-245</a> <a href=\"https://doi.org/10.1016/j.clinthera.2010.02.010\" rel=\"nofollow noreferrer\">https://doi.org/10.1016/j.clinthera.2010.02.010</a></p>\n\n<p>As others have pointed out, the relationship between disease activity on an endoscopic level and symptom burden for the patient do not necessarily correlate well.</p>\n", "score": 4 } ]
14,106
CC BY-SA 4.0
Ulcerative Colitis Disease Activity
[ "immune-system", "disease", "inflammation", "crohns", "ulcerative-colitis" ]
<p>Ulcerative colitis can be endoscopically assessed and characterized as 'active' or 'inactive'. I was wondering how those disease states are related. Do patients with UC regularly alternate between active and inactive states? Or are there periods of activity flaring up, etc? </p> <p>Context: Researcher looking at a dataset: GSE59071 from Vanhove et al. 2015. They have both of those states, but they don't mention the process behind the original diagnosis/significance of disease activity.</p> <p><sub>(Paper: <a href="https://academic.oup.com/ibdjournal/article-abstract/21/11/2673/4579337?redirectedFrom=fulltext" rel="nofollow noreferrer">Wiebe Vanhove et al.: "Strong Upregulation of AIM2 and IFI16 Inflammasomes in the Mucosa of Patients with Active Inflammatory Bowel Disease" Inflammatory Bowel Diseases, Volume 21, Issue 11, 1 November 2015</a>, Pages 2673–2682, <a href="https://doi.org/10.1097/MIB.0000000000000535" rel="nofollow noreferrer">https://doi.org/10.1097/MIB.0000000000000535</a><br> <a href="https://www.ncbi.nlm.nih.gov/pubmed/26313692/" rel="nofollow noreferrer">Pubmed ID 26313692</a> or <a href="https://sci-hub.tw/https://www.ncbi.nlm.nih.gov/pubmed/26313692/" rel="nofollow noreferrer">here</a>)</sub></p>
7
https://medicalsciences.stackexchange.com/questions/14135/what-causes-diabetes-mellitus-type-2
[ { "answer_id": 15664, "body": "<p>The modern theory on the causation of Type 2 Diabetes Mellitus is known as the twin cycle hypothesis</p>\n\n<p><a href=\"https://i.stack.imgur.com/nG9k6.jpg\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/nG9k6.jpg\" alt=\"Twin cycle hypothesis\"></a>.</p>\n\n<blockquote>\n <p>The twin cycle hypothesis of the etiology of type 2 diabetes. During long-term intake of more calories than are expended each day, any excess carbohydrate must undergo de novo lipogenesis, which particularly promotes fat accumulation in the liver. Because insulin stimulates de novo lipogenesis, individuals with a degree of insulin resistance (determined by family or lifestyle factors) will accumulate liver fat more readily than others because of higher plasma insulin levels. In turn, the increased liver fat will cause relative resistance to insulin suppression of hepatic glucose production. Over many years, a modest increase in fasting plasma glucose level will stimulate increased basal insulin secretion rates to maintain euglycemia. The consequent hyperinsulinemia will further increase the conversion of excess calories to liver fat. A cycle of hyperinsulinemia and blunted suppression of hepatic glucose production becomes established. Fatty liver leads to increased export of VLDL triacylglycerol,85 which will increase fat delivery to all tissues, including the islets. This process is further stimulated by elevated plasma glucose levels.85 Excess fatty acid availability in the pancreatic islet would be expected to impair the acute insulin secretion in response to ingested food, and at a certain level of fatty acid exposure, postprandial hyperglycemia will supervene. The hyperglycemia will further increase insulin secretion rates, with consequent enhancement of hepatic lipogenesis, spinning the liver cycle faster and driving the pancreas cycle. Eventually, the fatty acid and glucose inhibitory effects on the islets reach a trigger level that leads to a relatively sudden onset of clinical diabetes. </p>\n</blockquote>\n\n<p>The observation that bariatric surgery often reversed T2DM was the genesis of this theory, and extreme low calorie diets have confirmed the reversal of T2DM simulating the period of starvation that occurs following bariatric surgery. Interestingly, even though insulin sensitivity is restored in the liver by calorie loss, it is still present in the peripheral muscles.</p>\n\n<p>Another recent observation is that <a href=\"https://academic.oup.com/ajcn/article/105/3/723/4569701\" rel=\"nofollow noreferrer\">diets high in saturated fat</a> predispose to peripheral insulin resistance.</p>\n\n<blockquote>\n <p>Conclusions: In a Mediterranean trial focused on dietary fat interventions, baseline intake of saturated and animal fat was not associated with T2D incidence, but the yearly updated intake of saturated and animal fat was associated with a higher risk of T2D. Cheese and butter intake was associated with a higher risk of T2D, whereas whole-fat yogurt intake was associated with a lower risk of T2D. [2]</p>\n</blockquote>\n\n<p>So excess calories, particularly of saturated fat, would appear to be the cause of T2DM.</p>\n\n<ol>\n<li><a href=\"https://www.medscape.com/viewarticle/781719_7\" rel=\"nofollow noreferrer\">https://www.medscape.com/viewarticle/781719_7</a></li>\n<li><em>The American Journal of Clinical Nutrition, Volume 105, Issue 3, 1 March 2017, Pages 723–735, <a href=\"https://doi.org/10.3945/ajcn.116.142034\" rel=\"nofollow noreferrer\">https://doi.org/10.3945/ajcn.116.142034</a></em></li>\n</ol>\n", "score": 3 }, { "answer_id": 14773, "body": "<blockquote>\n <p>Type 2 diabetes is characterized by a combination of peripheral\n insulin resistance and inadequate insulin secretion by pancreatic\n beta cells. Insulin resistance, which has been attributed to\n <strong>elevated levels of free fatty</strong> acids and <strong>proinflammatory cytokines</strong> in\n plasma, leads to decreased glucose transport into muscle cells,\n elevated hepatic glucose production, and increased breakdown of fat.</p>\n</blockquote>\n\n<p><br/></p>\n\n<blockquote>\n <p>For type 2 diabetes mellitus to occur, both <strong>insulin resistance</strong> and\n <strong>inadequate insulin secretion</strong> must exist. For example, all overweight\n individuals have insulin resistance, but diabetes develops only in\n those who cannot increase insulin secretion sufficiently to compensate\n for their insulin resistance. Their insulin concentrations may be\n high, yet inappropriately low for the level of glycemia.</p>\n</blockquote>\n\n<p>A simplified scheme for the pathophysiology of abnormal glucose metabolism in type 2 diabetes mellitus is depicted in the image below:</p>\n\n<p><a href=\"https://i.stack.imgur.com/XQ7E5.jpg\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/XQ7E5.jpg\" alt=\"enter image description here\"></a></p>\n\n<p>Reference</p>\n\n<ol>\n<li><a href=\"https://emedicine.medscape.com/article/117853-overview#a3\" rel=\"nofollow noreferrer\">Type 2 Diabetes Mellitus: Pathophysiology</a></li>\n</ol>\n", "score": 2 }, { "answer_id": 14776, "body": "<p>When a person (pancreas) is unable to produce requisite amount of insulin to maintain blood glucose levels or when their body is not able to utilize the manufactured insulin, that person is said to have affected by Type 2 diabetes.</p>\n\n<p>Probable causes include but are not limited to: person's age, weight, genetics, lack of exercise, ethnicity and lifestyle.</p>\n\n<blockquote>\n <p>Risk factors for the development of type 2 diabetes: There is evidence\n that certain ethnic groups have a predisposition to type 2 diabetes in\n the presence of the same risk factors. For example, among adult South\n Asians there are higher rates of obesity, central fat distribution,\n and resulting insulin resistance than in white populations.\n Nutritional factors (reduced intake of vitamin B12 and folate, because\n of prolonged cooking of vegetables) and lower levels of habitual\n physical activity also play their part in increasing the risk of\n diabetes in these population groups.</p>\n</blockquote>\n\n<p>Here's a reference <a href=\"http://pmj.bmj.com/content/81/958/486\" rel=\"nofollow noreferrer\">link</a>.</p>\n", "score": 0 } ]
14,135
CC BY-SA 3.0
What causes Diabetes mellitus type 2?
[ "cause-and-effect", "type-2-diabetes" ]
<p>We have questions on how to <a href="https://health.stackexchange.com/questions/10718/preventing-diabetes-mellitus">prevent</a> or on how to <a href="https://health.stackexchange.com/questions/13956/is-type-2-diabetes-reversible">reverse</a> diabetes type 2. There are also some minor details about <a href="https://health.stackexchange.com/questions/51/is-there-evidence-that-eating-too-much-sugar-can-increase-the-risk-of-diabetes">isolated</a> potential causes.</p> <p>No question to the overall causal explanation.</p> <p>Our friendly neighbours at the wikipedia write about <a href="https://en.wikipedia.org/wiki/Diabetes_mellitus_type_2" rel="noreferrer">Diabetes mellitus type 2</a>:</p> <blockquote> <p>Diabetes mellitus type 2 (also known as type 2 diabetes) is a long-term metabolic disorder that is characterized by high blood sugar, insulin resistance, and relative lack of insulin.</p> </blockquote> <p>But looking at the section for causes there are just listings of contributing factors: lifestyle, genetics, and medical conditions.</p> <blockquote> <p><a href="https://www.webmd.com/diabetes/guide/diabetes-basics#2-3" rel="noreferrer">Type 2 diabetes is the most common form of diabetes, affecting almost 18 million Americans. While most of these cases can be prevented, it remains for adults the leading cause of diabetes-related complications such as blindness, non-traumatic amputations, and chronic kidney failure requiring dialysis. Type 2 diabetes usually occurs in people over age 40 who are overweight, but can occur in people who are not overweight.</a> </p> </blockquote> <p>That leaves one wondering:</p> <p>Is this wikipedia definition exhaustive? What is the main cause of diabetes type 2? Is this even the right way to phrase this question? Are their multiple main causes? If yes, how are they related to one another? </p> <p>What causes Diabetes mellitus type 2?</p>
7
https://medicalsciences.stackexchange.com/questions/14163/which-type-of-doctor-to-see-when
[ { "answer_id": 14190, "body": "<h2>Primary Care</h2>\n<ul>\n<li><p><strong>Primary Care Physician</strong> (<strong>General Practitioner</strong>)<br />\n<em>In the USA: primary care specialties include Family Medicine (all ages), Internal Medicine (adults), Pediatrics (children). Nurse Practitioners and Physician Assistants are also primary care providers who work alongside physicians.</em></p>\n<p>This is often the best place to start, as they are well-versed in managing most conditions and injuries. If it is complicated enough to require a subspecialist who spent years studying just that area (see below), the PCP will be able to refer you to the right subspecialist. PCPs are experts in evaluating and managing &quot;the big picture&quot; of your overall health. Make sure you bring ALL results with you to your PCP/GP so that they can coordinate your care! Many of them do minor procedures such as biopsies, cyst removal, joint injections, IUDs. They also specialize in general wellness and disease prevention from immunizations to mammos and PAP.</p>\n</li>\n</ul>\n<hr />\n<h2>Subspecialists</h2>\n<ul>\n<li><strong>Allergy and Immunology</strong><br />\nDiagnose, treat and manage allergies (hypersensitivity of the immune system to everyday environmental influences like pollen, which usually cause very little problems in most other people) that manifest in conditions like hay fever, food allergies, allergic asthma, or anaphylaxis. Also immune disorders, such as immunodeficiencies; there is some overlap with Rheumatology with autoimmune disorders.</li>\n</ul>\n<hr />\n<ul>\n<li><strong>Anaesthesiology</strong><br />\nFocuses on maintaining stable vital body functions before, during and after surgery. They also manage pain both in the acute setting (like surgery) and chronic <em>pain management</em>.</li>\n</ul>\n<hr />\n<ul>\n<li><strong>Gastroenterology</strong>.<br />\nGastroenterologists are physicians with training in the management of diseases of the gastrointestinal tract and liver. Their field, gastroenterology, is the study of the normal function and diseases of the esophagus, stomach, small intestine, colon and rectum, pancreas, gallbladder, bile ducts and liver. In essence, all normal activity and disease of the digestive organs are part of the study of Gastroenterology.</li>\n</ul>\n<hr />\n<ul>\n<li><strong>Hepatology</strong><br />\nDiseases of the liver, such as cirrhosis due to hepatitis or alcohol.</li>\n</ul>\n<hr />\n<ul>\n<li><strong>Orthopedic Surgery</strong><br />\nExperts in evaluation and treatment of complicated musculoskeletal injuries and conditions. This is primarily a surgical specialty, but also perform non-surgical treatments such as bracing or joint injections, and refer out for physical therapy.</li>\n</ul>\n<hr />\n<ul>\n<li><strong>Pathology</strong><br />\nYou usually won't see this specialist personally; they work behind the scenes.\nThey specialize in diagnosing diseases based on examination of tissue, body fluids, organs, or autopsies (anatomical and clinical pathology). There is also forensic pathology, which you hopefully won’t encounter all too soon.</li>\n</ul>\n<hr />\n<ul>\n<li><strong>Physical Therapy</strong><br />\nThis is not a medical doctor, but is a trained expert (usually at doctorate-level) in treating musculoskeletal injuries and conditions using strengthening and flexibility exercises, stretching, massage, ice/heat, and modalities such as ultrasound, electric stimulation, and other therapies. This includes things like rehab after hip or knee surgery, arthritis, sprains, back injuries, and even tension headaches.</li>\n</ul>\n<h2>This list is work in progress, under on-going maintenance, and definitely not exhaustive</h2>\n", "score": 4 } ]
14,163
CC BY-SA 3.0
Which type of doctor to see when?
[ "practice-of-medicine" ]
<p>What type of doctors are specialised in what fields?</p> <p>Ideally, below is a Community List of which doctors are responsible for what. This list is not exhaustive and should not be taken at face value depending on medical circumstances, but it should give one the broadest overview we can give. </p>
7
https://medicalsciences.stackexchange.com/questions/14678/how-much-is-green-tea-really-good-against-tooth-decay
[ { "answer_id": 14687, "body": "<p>Green tea, or any real tea made from the Camellia sinensis plant, has many advantages as a go-to beverage.</p>\n\n<p>It itself does <em>not</em> contain significant amounts of sugar, it has an enamel preserving pH level (that is: it is non-acidic). Some compounds (like the <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/19397954\" rel=\"nofollow noreferrer\">poyphenols</a>) have shown some activity against harmful bacteria causing gingivitis or caries.</p>\n\n<p>The most significant part plays the sometimes enormous amount of fluoride tea contains. Fluoride hardens the enamel against acids from bacteria metabolising around. In fact tea has often <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5497633/\" rel=\"nofollow noreferrer\">so much fluoride that this is much more likely to be a health concern</a> than the caffeine content some hysterics worry about. (<a href=\"https://www.nhs.uk/news/food-and-diet/do-fluoride-levels-in-cheap-tea-pose-a-health-risk/\" rel=\"nofollow noreferrer\">Or not?</a> Since everyone should only buy tea that was tested for pesticides, radioactivity, and other contaminations, why not demand a chemical analysis sheet as well?)</p>\n\n<ol>\n<li><p>Green tea is tooth friendly. It does not cause or aggravate tooth decay. On the contrary, it usually makes your teeth stronger (and stains them, alas) – Green tea will not stop or reverse caries.</p></li>\n<li><p>Every sugar drink replaced by tea helps. How much tea is needed for the effects of fluoride to be significant depends on other dietary factors, water fluoridation and tooth paste used. The amount of tea is therefore impossible to gauge exactly but an upper limit is dependent on how much tea a user can take (if the fluoride content is kept well below a dosage causing problems like fluorosis) since caffeine and tannins are not equally well tolerated by everyone.</p></li>\n<li><p>Sources:</p></li>\n</ol>\n\n<blockquote>\n <p><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/27107380\" rel=\"nofollow noreferrer\"><strong>Inhibition of Streptococcus mutans biofilm formation using extracts from Assam tea compared to green tea:</strong></a><br>\n <strong>Results:</strong>\n Assam tea has stronger biofilm inhibition activity against S. mutans than green tea. A substance of &lt;10kDa in mass in Assam tea had a high concentration of galloylated catechins and a stronger biofilm inhibiting activity than green tea. In contrast, substances >10kDa in mass from green tea included higher concentrations of polysaccharides composed of galacturonic acid, such as pectin, that enhance biofilm formation.<br>\n <strong>Conclusions:</strong>\n The higher concentrations of galloylated catechins in Assam tea may assist in prevention of dental caries, whereas in green tea, this mode of inhibition was likely offset by the presence of pectin. Purification of catechins in partially fermented Assam tea with lower-molecular-weight polysaccharide than pectin may be useful for developing oral care products such as toothpaste and oral care gel pastes.</p>\n \n <p><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/27313414\" rel=\"nofollow noreferrer\"><strong>Inhibition of salivary amylase by black tea in high-caries and low-caries index children: A comparative in vivo study:</strong></a> <br>\n <strong>Results:</strong> The average ratio of maltose to sucrose ratio percentage reduction in high-caries group was 43.63% and 41.17% in no caries group which was highly significant (P &lt; 0.005) while the intergroup comparison was found statistically insignificant.<br>\n <strong>Conclusions:</strong>\n Tea decoction has inhibitory effect on salivary amylase activity thus dental caries. The effect was statistically insignificant in children with high- and no-caries index.<br><br>\n <a href=\"http://An%20In%20vitro%20Study%20to%20Compare%20the%20Effect%20of%20Different%20Types%20of%20Tea%20with%20Chlorhexidine%20on%20Streptococcusmutans.\" rel=\"nofollow noreferrer\"><strong>An In vitro Study to Compare the Effect of Different Types of Tea with Chlorhexidine on Streptococcusmutans:</strong></a><br>\n <strong>Results:</strong>\n The mean zone of inhibition of the aqueous extracts of green tea, black tea, oolong tea and chlorhexidine was found to be 16.33 mm, 10.33 mm, 19.66 mm and 22 mm respectively. The mean zone of inhibition of the ethanol extracts of green tea, black tea, oolong tea and chlorhexidine was found to be 14 mm, 9 mm, 20.66 mm and 22 mm respectively. The study result state that the inhibitory effect of chlorhexidine is almost similar to that of oolong tea followed by green tea and black tea.<br>\n <strong>Conclusion:</strong> From the present study, it can be concluded that the aqueous and ethanol extracts of oolong tea showed highest antimicrobial activity compared to green tea and black tea.<br><br>\n <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/27386001\" rel=\"nofollow noreferrer\"><strong>Green Tea (Camellia Sinensis): Chemistry and Oral Health:</strong></a><br>\n Green tea is a widely consumed beverage worldwide. Numerous studies have suggested about the beneficial effects of green tea on oral conditions such as dental caries, periodontal diseases and halitosis. However, to date there have not been many review articles published that focus on beneficial effects of green tea on oral disease. The aim of this publication is to summarize the research conducted on the effects of green tea on oral cavity. Green tea might help reduce the bacterial activity in the oral cavity that in turn, can reduce the aforementioned oral afflictions. Furthermore, the antioxidant effect of the tea may reduce the chances of oral cancer. However, more clinical data is required to ascertain the possible benefits of green tea consumption on oral health.</p>\n</blockquote>\n\n<p>A more comprehensive overview with a lot of references are in each: <br>\n<a href=\"https://www.crcpress.com/Green-Tea-Health-Benefits-and-Applications/Hara/p/book/9780824704704\" rel=\"nofollow noreferrer\">Yukihiko Hara: \"Green Tea: Health Benefits and Applications\", (Food science and technology ; 106), Marcel Dekker: New York, Basel, 2001.</a></p>\n\n<p><a href=\"https://www.novapublishers.com/catalog/product_info.php?products_id=9415\" rel=\"nofollow noreferrer\">Helen Mckinley &amp; Mark Jamieson: \"Handbook of Green Tea and Health Research\", Food and Beverage Consumption and Health Series, Nova Science Publishers, New York, 2009.</a></p>\n\n<p><a href=\"https://www.crcpress.com/Tea-and-Tea-Products-Chemistry-and-Health-Promoting-Properties/Ho-Lin-Shahidi/p/book/9780849380822\" rel=\"nofollow noreferrer\">Chi-Tang Ho &amp; Jen-Kun Lin &amp; Fereidoon Shahidi: \"Tea and Tea Products. Chemistry and Health-Promoting Properties\", CRC Press: Boca Raton, 2009.</a></p>\n", "score": 7 } ]
14,678
CC BY-SA 4.0
How much is green tea really good against tooth decay?
[ "dentistry", "research", "tea", "cavity" ]
<p>I heard that many times:</p> <blockquote> <p>Green tea is good for cavity protection.</p> </blockquote> <p>For example, <a href="http://www.besthealthmag.ca/best-you/oral-health/5-ways-green-tea-is-good-for-your-oral-health/" rel="nofollow noreferrer">it is written on this site</a> (the first one googled):</p> <blockquote> <ol> <li>Cavity prevention</li> </ol> <p>Because green tea controls bacteria and lowers the acidity of saliva and dental plaque, it may be a useful tool in preventing cavities. A recent Egypt-based study tested people before and after they gave their mouths a five-minute rinse with green tea. The test subjects had less bacteria and acid in their mouths, as well as reduced gum bleeding. Other research has found that drinking green tea shows promise when it comes to preventing tooth decay.</p> </blockquote> <p>But I never heard such a thing from some reliable source (my dentist doesn't know anything about that). The question has three parts really, they are:</p> <ol> <li>Is green tea really good against cavity?</li> <li>How much? Is it even worth mentioning?</li> <li>Do you have some reliable source? (big medical research, world respected dentist, or something like these)</li> </ol>
7
https://medicalsciences.stackexchange.com/questions/14795/is-water-flossing-more-efficient-than-string-flossing-to-remove-plaques-from-too
[ { "answer_id": 14978, "body": "<p>The latest systematic review in this issue found:\nthere is only weak, very low quality and unreliable evidence avalaible\nfor floss the magnitude of the effect was small, for woodsticks and oral irrigators was weak and for interdental brushes was large</p>\n<p>Main conclusions are:</p>\n<blockquote>\n<p>There is weak evidence that flossing plus toothbrushing compared to\ntoothbrushing alone has a small but significant effect on gingivitis.\nHowever, there is a lack of evidence for a concomitant reduction in\nplaque scores.</p>\n<p>The evidence for woodsticks and toothbrushing as\ncompared to toothbrushing alone was weak and showed that there is a\nbenefit of unclear magnitude with respect to bleeding scores but\nlacking evidence for a concomitant reduction of plaque.</p>\n<p>Moderate evidence was available for the efficacy of interdental brushes in addition to toothbrushing as compared with toothbrushing alone. This\ncorresponded to a 34% reduction in gingivitis and a 32% reduction in\nplaque scores, when standardizing the results retrieved from the use\nof different indices.</p>\n<p>There is weak evidence that the oral irrigator\nplus toothbrushing compared to regular oral hygiene has an effect on\ngingivitis. The magnitude remained unclear and it also lacked evidence\non a concomitant reduction of plaque scores.</p>\n<p>In all there is consistent evidence that suggests that inter-dental brushes are the most effective devices to remove inter-dental plaque. In addition, they are appreciated best by the patients.</p>\n</blockquote>\n<p>Anyway, you have to keep in mind that there there was insufficient evidence to determine whether interdental brushing reduced or increased levels of plaque when compared to flossing (<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/24353078\" rel=\"nofollow noreferrer\">source</a>).</p>\n<p>UPDATE Feb 2018: <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/29481764\" rel=\"nofollow noreferrer\">Higher frequency of interdental cleaning was correlated with increased periodontal health</a>.</p>\n<p>Source: <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/25581718\" rel=\"nofollow noreferrer\">J Clin Periodontol. 2015 Apr;42 Suppl 16:S92-105. doi: 10.1111/jcpe.12363.</a></p>\n", "score": 7 } ]
14,795
CC BY-SA 3.0
Is water flossing more efficient than string flossing to remove plaques from tooth surfaces?
[ "dentistry", "floss-flossing", "plaque" ]
<p>Is water flossing more efficient than string flossing to remove plaques from tooth surfaces?</p> <hr> <p>I present below what I have found so far. In the following:</p> <ul> <li><a href="https://en.wikipedia.org/wiki/Water_Pik,_Inc." rel="noreferrer">Waterpik</a> is a manufacturer of water flossing devices. By extension, Waterpik = a type of water flossing device.</li> <li>oral irrigator = water flossing device</li> </ul> <p>{1} (published in 2013) says:</p> <blockquote> <p>RESULTS: The WF group had a 74.4% reduction in whole mouth plaque and 81.6% for approximal plaque compared to 57.7% and 63.4% for the SF group, respectively (p &lt; 0.001). <strong>The differences between the groups showed the water flosser was 29% more effective than string floss for overall plaque removal</strong> and approximal surfaces specifically (p &lt; 0.001). The WF group was more effective in removing plaque from the marginal, lingual, and facial regions; 33%, 39%, and 24%, respectively (p &lt; 0.001).</p> <p>CONCLUSION: The Waterpik Water Flosser and manual toothbrush is significantly more effective than a manual brush and string floss in removing plaque from tooth surfaces.</p> </blockquote> <p>and {3} (published in 2009) says:</p> <blockquote> <p>RESULTS: The standard jet tip removed 99.99% of the salivary (ex vivo) biofilm, and the orthodontic jet tip removed 99.84% of the salivary biofilm. Observation of the remaining four teeth by the naked eye indicated that the orthodontic jet tip removed significant amounts of calcified (in vivo) plaque biofilm. This was confirmed by SEM evaluations.</p> <p>CONCLUSION: <strong>The Waterpik dental water jet (Water Pik, Inc, Fort Collins, CO) can remove both ex vivo and in vivo plaque biofilm significantly.</strong></p> </blockquote> <p>whereas <a href="https://www.livestrong.com/article/287399-waterpik-vs-floss/" rel="noreferrer">https://www.livestrong.com/article/287399-waterpik-vs-floss/</a> (<a href="https://web.archive.org/web/20171228203636/https://www.livestrong.com/article/287399-waterpik-vs-floss/" rel="noreferrer">mirror</a>) says, without citing any scientific study:</p> <blockquote> <p>The downside: <strong>A Waterpik doesn’t remove plaque from teeth as well as floss</strong>. “Flossing scrapes off the sticky film of bacteria, while a Waterpic just rinses it,” Hayes explains. MayoClinic.com <a href="https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/dental-floss/faq-20058112" rel="noreferrer">says</a> (<a href="https://web.archive.org/web/20171228203710/https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/dental-floss/faq-20058112" rel="noreferrer">mirror</a>) using a Waterpik isn't a substitute for flossing.</p> </blockquote> <p>and {2} (published in 2008) says:</p> <blockquote> <p><strong>As an adjunct to brushing, the oral irrigator does not have a beneficial effect in reducing visible plaque.</strong> However, there is a positive trend in favour of oral irrigation improving gingival health over regular oral hygiene or toothbrushing only.</p> </blockquote> <p>I wonder if there now exists a scientific consensus on the efficiency of water flossing compared to string flossing for removing plaques from tooth surfaces.</p> <hr> <p>References:</p> <ul> <li>{1} Lyle, Deborah M., Jimmy G. Qaqish, and Reinhard Schuller. "Evaluation of the plaque removal efficacy of a water flosser compared to string floss in adults after a single use." J Clin Dent 24 (2013): 37-42. <a href="https://scholar.google.com/scholar?cluster=13416577876110061555&amp;hl=en&amp;as_sdt=0,5" rel="noreferrer">https://scholar.google.com/scholar?cluster=13416577876110061555&amp;hl=en&amp;as_sdt=0,5</a> ; <a href="https://www.ncbi.nlm.nih.gov/pubmed/24282867" rel="noreferrer">https://www.ncbi.nlm.nih.gov/pubmed/24282867</a></li> <li>{2} Husseini, A., D. E. Slot, and G. A. Van der Weijden. "The efficacy of oral irrigation in addition to a toothbrush on plaque and the clinical parameters of periodontal inflammation: a systematic review." International journal of dental hygiene 6, no. 4 (2008): 304-314. <a href="https://scholar.google.com/scholar?cluster=17144292305835117689&amp;hl=en&amp;as_sdt=0,5" rel="noreferrer">https://scholar.google.com/scholar?cluster=17144292305835117689&amp;hl=en&amp;as_sdt=0,5</a>; <a href="https://www.ncbi.nlm.nih.gov/pubmed/19138181" rel="noreferrer">https://www.ncbi.nlm.nih.gov/pubmed/19138181</a></li> <li>{3} Gorur, A; Lyle, DM; Schaudinn, C; Costerton, JW (2009). "Biofilm removal with a dental water jet". Compendium of continuing education in dentistry. 30 Spec No 1: 1–6. PMID 19385349. <a href="https://scholar.google.com/scholar?cluster=3786584786784088020&amp;hl=en&amp;as_sdt=0,5" rel="noreferrer">https://scholar.google.com/scholar?cluster=3786584786784088020&amp;hl=en&amp;as_sdt=0,5</a> ; <a href="https://www.ncbi.nlm.nih.gov/pubmed/19385349" rel="noreferrer">https://www.ncbi.nlm.nih.gov/pubmed/19385349</a></li> </ul>
7
https://medicalsciences.stackexchange.com/questions/15123/does-stopping-fever-hinder-the-process-of-killing-bacteria-via-fever
[ { "answer_id": 15124, "body": "<p>This is a great question, an area of active debate, and a personal interest of mine. I actually just did a presentation on this, so this answer will probably have more information in it than you need, but I'll add it for completeness.</p>\n\n<p><strong>Fever as an Adaptive Response</strong></p>\n\n<p>The first important thing to know about fever is that it is something your body initiates when you get certain types of infections. It is not a direct consequence of the bacteria or viruses themselves. <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4944485/\" rel=\"nofollow noreferrer\">Instead, white blood cells release a chemical messenger called prostaglandin E2. This travels to the brain, where it causes the body to start ramping up its set point for temperature</a>-- essentially turning up the thermostat.</p>\n\n<p>This is important because it seems to indicate an evolved response-- perhaps there is an evolutionary advantage to a fever in the setting of infection. <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4944485/\" rel=\"nofollow noreferrer\">Many bacteria are very temperature sensitive</a>, so this idea makes sense.</p>\n\n<p><strong>The Data</strong></p>\n\n<p>Many papers have been published on the effect of fever on infection-- here are just a few:</p>\n\n<ul>\n<li><a href=\"https://www.sciencedirect.com/science/article/pii/S0140673697022551\" rel=\"nofollow noreferrer\">Patients who don't take acetaminophen/ paracetamol clear the malaria parasite faster than those who control their fever</a></li>\n<li><a href=\"http://www.physiology.org/doi/abs/10.1152/jappl.1992.73.4.1517\" rel=\"nofollow noreferrer\">Heat-stressed rats are more resistant to a common bacterial toxin than rats with a normal body temperature</a></li>\n</ul>\n\n<p>In critically ill patients (my area of interest), there have been several interesting studies. In <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/16433601\" rel=\"nofollow noreferrer\">this randomized controlled trial</a> (RCT) from 2005, they compared mortality in ICU patients where fevers were controlled with acetaminophen/ paracetamol and where fevers were not controlled. They actually had to stop the trial early because death rates in the group getting acetaminophen/ paracetamol were much higher.</p>\n\n<p><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/22373120\" rel=\"nofollow noreferrer\">This prospective study</a> (not randomized) from 2012 looked at over 1400 critically ill patients, and found that treating fever doubled the mortality rate.</p>\n\n<p><a href=\"https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0031168/\" rel=\"nofollow noreferrer\">This meta-analysis</a>, which included 11 studies, found a \"trend towards higher mortality for aggressive treatment\" of fever, though their p-value (how likely it is their findings are due to chance) was 0.09, which is higher than the 0.05 that is traditionally used as the cutoff for statistical significance.</p>\n\n<p><strong><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/28221185\" rel=\"nofollow noreferrer\">The most high-powered meta-analysis done to date</a></strong>, which included 16 studies and a total of about 20,000 critically ill patients, found less dramatic results-- essentially concluding that it makes no difference if you treat a fever or not.</p>\n\n<p><strong>Important considerations:</strong></p>\n\n<p>Most of the studies done here are in critically ill patients, with mortality as the final endpoint. You can make a case that in those patients, you may be better off not treating fever, since you want to keep them alive.</p>\n\n<p><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4944485/\" rel=\"nofollow noreferrer\">The vast majority of fevers are due to respiratory viral illnesses</a>. These have low mortality rates, and so rather than trying to lower mortality, <strong>you're trying to minimize the symptoms</strong>. And it sucks to have a fever. So for most people who do not need to get admitted to the hospital, treating a fever is a tradeoff between potentially getting better faster (an UNPROVEN benefit, as far as I could find), and not having a fever.</p>\n\n<p>If a person is willing to sweat it out with the hope that the disease will run its course faster, that's perfectly reasonable. And if they are ok with the disease taking a little longer to clear from the body as long as they aren't sweating, shaking, and burning up, that makes a lot of sense too.</p>\n\n<p>I should also note that there are times when a fever IS extremely dangerous-- if it's over about 106 it can lead to brain damage. All of the studies in humans treated fever if it went above about 104 degrees.</p>\n\n<p><strong>TL;DR:</strong> You are onto something! There is a lot of data out there that supports the hypothesis that treating fever is bad for you (or at least not any different from doing nothing).</p>\n", "score": 7 } ]
15,123
CC BY-SA 3.0
Does stopping fever hinder the process of killing bacteria via fever?
[ "immune-system", "bacteria", "virus", "fever" ]
<p>Since the body produces fever in order to kill bacteria, wouldn't decreasing the fever by taking anti fever medication decrease the body's ability to fight the bacteria?</p> <p>Assuming you have non life threatening fever wouldn't it be better to let it run its course instead of immediately decreasing it with medication?</p>
7
https://medicalsciences.stackexchange.com/questions/15184/how-can-i-learn-to-swallow-pills-without-gagging
[ { "answer_id": 15185, "body": "<p>If you are able to swallow pills but find it difficult, the following tips will help:</p>\n\n<ul>\n<li>take a sip of water before putting the pill in your mouth, and drink more water after putting the pill in as well</li>\n<li>do not lift your chin up as you try to swallow - this actually makes it harder. If anything, push your chin down into your chest a little while swallowing (called the \"lean forward method\" in <a href=\"https://www.health.harvard.edu/blog/two-tricks-make-easier-swallow-pills-201411137515\" rel=\"noreferrer\">this article</a>, which has other tips as well.)</li>\n<li>if you are cutting the pill to swallow two small halves, try not doing that - the rough edges of a cut pill add to the difficulty substantially. You may not believe the larger whole pill will be easier to swallow, but it often is</li>\n<li>ask your pharmacist if you can dissolve the pill in water or mix it in with applesauce or pudding</li>\n</ul>\n\n<p>If you cannot swallow pills at all, you can learn to do so. (<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/25896843\" rel=\"noreferrer\">This literature review</a> found 5 studies that all showed children can be taught to swallow pills.) Here is what worked for me. Start by buying some candy that mimics pill shape. Skittles, M&amp;Ms, or the like are good choices - they have a slightly hard and slippery coating that makes it easier. M &amp; M's have a \"mini\" that is very small and a good one to start with. Choose a candy you like to eat. If you're trying to swallow it and failing, you can always just chew it. (For a small child, I had great success with putting out 5 candies and saying \"once you swallow one whole, the rest are yours to chew.\")</p>\n\n<p>Every day, try to swallow one of these candies using the tips above. When you can consistently swallow one mini at will, try moving up to the regular size M &amp; M or Skittles. If you can do this then you can take the majority of pills, though ones without a smooth coating will be more difficult. Painkillers like Advil and Tylenol all come in a coated version that is easier to swallow. Many prescription pills are smaller than an M&amp;M or a Skittle, so you will have won most of the battle at this point.</p>\n\n<p>If you have a large pill that you need to take, you can work your way up to it by practicing with vitamins, which come in a variety of sizes and are safe to take every day. Once you have learned to take a large pill, the skill will stay with you and be useful for decades to come.</p>\n", "score": 7 } ]
15,184
CC BY-SA 3.0
How can I learn to swallow pills without gagging?
[ "medications", "pill" ]
<p>Many people have difficulty swallowing pills or even find themselves unable to do so. While some medications are available in other forms, many are not.</p> <p>Is it possible to learn how to swallow pills? Are there tricks with using water, head position, etc that make it easier?</p>
7
https://medicalsciences.stackexchange.com/questions/15519/is-a-drug-holiday-off-bisphosphonate-therapy-a-valid-strategy-in-the-management
[ { "answer_id": 25097, "body": "<p>Bisphosphonate drug holidays should be considered if the person has taken the drug for an extended period of time and have a reservoir built up in their bone. Secondary therapy should be considered during the holiday to maintain bone density.</p>\n<p>Source :\nDiab, D. L., &amp; Watts, N. B. (2013). Bisphosphonate drug holiday: who, when and how long. Therapeutic advances in musculoskeletal disease, 5(3), 107–111. <a href=\"https://doi.org/10.1177/1759720X13477714\" rel=\"nofollow noreferrer\">https://doi.org/10.1177/1759720X13477714</a></p>\n", "score": 1 } ]
15,519
CC BY-SA 3.0
Is a drug holiday off bisphosphonate therapy a valid strategy in the management of osteoporosis?
[ "osteoporosis" ]
<p>The most commonly prescribed treatment for osteoporosis is bisphosphonate therapy eg. Alendronate and Zolendronic Acid (by infusion). It's a common practice to stop therapy after 5 years, and then monitor bone markers to see if the osteoporosis is continuing. This seems to have arisen as a result of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4480549/" rel="noreferrer">atypical femoral fractures</a> that occurred on bisphosphonate therapy possibly on the basis of accumulated microcracks.</p> <p>But some patients need to continue steroids which leads to continuing bone loss off therapy.</p> <p>What's the risk of an atypical fracture with continued treatment vs a fracture from ceasing anti-osteoporosis treatment?</p>
7
https://medicalsciences.stackexchange.com/questions/16175/why-do-surgeons-wear-blue-aprons-during-surgeries
[ { "answer_id": 16176, "body": "<p>Initially surgeons did wear white in the operating theater, but there were two large problems with this. Firstly, under the bright lights, the white reflects too much light making an inordinate amount of glare making it difficult to see. Secondly, the white cloth highlighted the red blood which many people found objectionable. As a result, most operating theaters have switched to either a blue or green colored cloth. This reduces the glare and when the red blood gets on it, the cloth appears black.</p>\n\n<p>Some hospitals do identify specialties/departments by different colored scrubs, but this is outside of the operating theater. Inside the theater, most specialties/departments within the same hospital wear the same color. </p>\n", "score": 9 } ]
16,175
CC BY-SA 4.0
Why do surgeons wear blue aprons during surgeries?
[ "blood", "surgery", "practice-of-medicine", "hospital" ]
<p>In most cases, the surgeon wears a white apron, but during a surgery he is wearing a blue apron, why blue? </p>
7
https://medicalsciences.stackexchange.com/questions/16236/is-a-vaginal-birth-still-medically-preferable-over-a-c-section
[ { "answer_id": 16238, "body": "<p>If we are assuming that there is no valid reason<sup>1</sup> for a c-section, a c-section is obsolete per definition. Any operation has risks and strains the body: The anesthesia, the cutting of the body to name the two obvious points. If an operation is not indicated, it shouldn’t be performed. So, if c-section are not medically indicated, they shouldn’t be performed.</p>\n<p>If there was a valid reason for the c-section, the answer is obvious: Do get a c-section.</p>\n<hr />\n<p>Some references:</p>\n<blockquote>\n<p>Based on the available data, and using internationally accepted methods to assess the evidence with the most appropriate analytical techniques, WHO concludes: Caesarean sections are effective in saving maternal and infant lives, but <em>only when they are required for medically indicated reasons</em>.</p>\n<p><sup>Emphasis Mine, Taken from <a href=\"http://apps.who.int/iris/bitstream/handle/10665/161442/WHO_RHR_15.02_eng.pdf;jsessionid=56C82847E77844D5EA214D5D5369B9D4?sequence=1\" rel=\"nofollow noreferrer\">WHO Statement on Caesarean Section Rates</a></p>\n</blockquote>\n<p>A more elaborate source:</p>\n<blockquote>\n<p><strong>Experts who believe c-sections should only be performed for medical reasons point to the risks.</strong> These include infection, dangerous bleeding, blood transfusions, and blood clots. Babies born by c-section have more breathing problems right after birth. Women who have c-sections stay at the hospital for longer than women who have vaginal births. Plus, recovery from this surgery takes longer and is often more painful than that after a vaginal birth. C-sections also increase the risk of problems in future pregnancies. Women who have had c-sections have a higher risk of uterine rupture. If the uterus ruptures, the life of the baby and mother is in danger. [...]</p>\n<p>The National Institutes of Health (NIH) and American College of Obstetricians (ACOG) <strong>agree that a doctor's decision to perform a c-section at the request of a patient should be made on a case-by-case basis and be consistent with ethical principles.</strong> ACOG states that &quot;<em>if the physician believes that (cesarean) delivery promotes the overall health and welfare of the woman and her fetus more than vaginal birth, he or she is ethically justified in performing</em>&quot; a c-section. Both organizations also say that c-section should never be scheduled before a pregnancy is 39 weeks, or the lungs are mature, unless there is medical need.</p>\n</blockquote>\n<p>If you are even more interested, <a href=\"https://www.acog.org/Clinical-Guidance-and-Publications/Obstetric_Care_Consensus_Series/Safe_Prevention_of_the-Primary-Cesarean-Delivery\" rel=\"nofollow noreferrer\">this is a great source as well</a>.</p>\n<hr />\n<p>1: These include psychological factors. If a to-be mother is as an example afraid of natural delivery, this can be considered a valid reason after evaluation. </sup></p>\n", "score": 3 } ]
16,236
CC BY-SA 4.0
Is a vaginal birth still medically preferable over a c-section?
[ "gynecology", "birth" ]
<p>I was always taught by my mom (who studied nursing and midwifery 30 years ago) that a vaginal birth is vastly preferable over a c-section in low-risk pregnancies. </p> <p>I'm not a medical professional, but my understanding from what she's said is that the baby benefits by moving through the birth canal and the recovery time for the mother is much lower than a c-section. I have done some googling on the subject and have found this to be the case. For example: <a href="https://www.livescience.com/45681-vaginal-birth-vs-c-section.html" rel="nofollow noreferrer">Vaginal Birth vs. C-Section: Pros &amp; Cons</a> </p> <p>As a result, I have been very surprised at the prevalence of elective c-sections amongst my friends and in my community. I know <em>no one</em> my age in my acquaintance who has had a vaginal birth. Everyone I have spoken to about this has chosen to voluntarily have a c-section for reasons of convenience ("my husband had work") or fear ("I'm squeamish and scared of labour"). </p> <p>I asked my obgyn about this and he seemed relatively nonchalant, that the recovery time wasn't that bad compared to an episiotomy and that no matter what there are risks. </p> <p>It is very clear that the mindset now has shifted significantly compared to what it was 30 years ago when my mom did her studies. Due to the conflicting information available, I'm really not sure which is preferable anymore.</p> <p><strong>I understand c-sections are more convenient, but are they considered medically preferable, or even on-par with a vaginal birth?</strong> Perhaps my understanding of the medical side of things (or what my mom taught me) is out of date or old fashioned.</p> <hr> <p>I'm only referring to low-risk pregnancies where the mother chooses an elective c-section beforehand even though she could give birth vaginally. Of course, emergency c-sections or scheduled c-sections (due to medical issues during pregnancy/birth) are a completely different case here.</p>
7
https://medicalsciences.stackexchange.com/questions/16310/coffee-for-solving-sleep-problems
[ { "answer_id": 16316, "body": "<p><strong>It is very difficult to prove a negative.</strong> This is true both because there always exists the possibility of a small effect that a given study is underpowered to find, and because of the chronic issue with reporting negative results in biomedical literature and science in general (that is, experiments with a negative result are less likely to be published).</p>\n\n<p>However, there is <strong>no recommendation for or substantial scientific evidence for sleep benefits of morning caffeine consumption</strong> and acute avoidance of caffeine, regardless of time of day, has been observed to have a modest improvement on sleep.</p>\n\n<p>Given the ubiquity of caffeine in society, the multitude of studies concerning caffeine, and the existence of studies that show that caffeine avoidance is better for sleep, I think there is a pretty solid body evidence that suggests any sleep-beneficial role of caffeine is either non-existent extremely minimal.</p>\n\n<p>Several authors have noted that peoples' <em>perceptions</em> of the impact of caffeine on sleep and wake are substantially exaggerated. Caffeine in regular users has little impact on sleep, and the immediate cognitive benefits of caffeine are mostly explainable by a reduction in baseline abilities under caffeine withdrawal. Similarly, sleep can improve in long-term users of caffeine when caffeine is withdrawn, but the effect is both small and short-lived.</p>\n\n<p>I think it is important to recognize that <em>adenosine is not</em> <strong><em>the only</em></strong> signal contributing to sleep pressure, and so it is problematic to treat the system like it is. Habitual caffeine users adapt to the caffeine intake by increasing adenosine receptor expression, but they may also adapt to the increased adenosine receptor expression with modification of other contributors to sleep.</p>\n\n<p>In the individuals of most concern: those with chronic insomnia or other sleep problems, their issues seem to persist despite the inherent increases in sleep pressure that people who lack sleep will accumulate, so there is unlikely to be a \"quick fix.\" The standard practice is an overall emphasis on \"sleep hygiene\" including setting a regular sleep-wake cycle, avoiding sleep-influencing substances including caffeine and alcohol, keep a standard and comfortable sleep environment, and exercise regularly: however, each of these strategies individually have only a modest impact.</p>\n\n<p>There is also the issue of individual differences: if someone sleeps better in the evening when they wake up with caffeine, then there is little reason to change. There just isn't any scientific evidence that suggests prescribing morning caffeine as a sleep aid.</p>\n\n<p>References</p>\n\n<hr>\n\n<p>James, J. E. (1998). Acute and chronic effects of caffeine on performance, mood, headache, and sleep. Neuropsychobiology, 38(1), 32-41.</p>\n\n<p>Nehlig, A. (2010). Is caffeine a cognitive enhancer?. Journal of Alzheimer's Disease, 20(s1), S85-S94.</p>\n\n<p>Sin, C. W., Ho, J. S., &amp; Chung, J. W. (2009). Systematic review on the effectiveness of caffeine abstinence on the quality of sleep. Journal of Clinical Nursing, 18(1), 13-21.</p>\n\n<p>Stepanski, E. J., &amp; Wyatt, J. K. (2003). Use of sleep hygiene in the treatment of insomnia. Sleep medicine reviews, 7(3), 215-225.</p>\n", "score": 2 } ]
16,310
CC BY-SA 4.0
Coffee for solving sleep problems?
[ "sleep", "coffee" ]
<p><a href="https://health.stackexchange.com/q/16279/6492">In this post</a> I asked whether Coffee use could cause an increase in adenosine levels as a result of the body’s adjustment to lower adenosine receptor activation. An answer stated that coffee use increases adenosine receptors in the long term. </p> <p>This got me thinking: If someone has sleep probems, whether due to <em>insomnia</em> or due to <em>stress</em>, could this problem be solved by drinking coffee <em>in the morning</em>?</p> <p>This would cause adenosine receptor activation to go down in the day, causing reduced drowsiness during the day, and cause a long term increase in receptors, so that when the coffee wears off in the evening, there should be an increase in drowsiness at night. </p> <p>This combination of increased night-time drowsiness and decreased day-time drowsiness seems to be precisely what people with sleep problems need, and yet sleep professionals always seem to advice against using coffee for people with sleep problems. </p> <p><strong>Is my hypothesis correct? How does this square with sleep professionals advice against coffee?</strong> </p> <p>(Obviously this would certainly not work if you drink coffee in the evening).</p>
7
https://medicalsciences.stackexchange.com/questions/16330/what-procedures-do-dentists-use-for-cleaning-teeth-is-there-variation-and-what
[ { "answer_id": 16335, "body": "<p><strong>Your question seems to be about the \"cleaning\" or periodontal maintenance portion of your appointment.</strong> (Periodontistry is a field in dentistry which is concerned with the gums or soft tissues around teeth)</p>\n\n<p><strong>As part of an initial exam or routine checkup, many dentists and their hygienists will perform all or some of the following steps</strong>:</p>\n\n<ul>\n<li>Assess if there were changes in your health (medical history).</li>\n<li>Perform a dental exam, including taking the necessary radiographs. <strong>It is here that the dentist uses a periodontal probe, an instrument that looks like a ruler to mesure the depth of the crevice around teeth</strong> (the space between the gums and the tooth) to assess changes in your periodontal \"gum\" health.</li>\n</ul>\n\n<p><a href=\"https://i.stack.imgur.com/Df0pm.png\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/Df0pm.png\" alt=\"Periodontal Probe that is also my profile picture, most likely the UNC-15\"></a></p>\n\n<p><strong>During the second half of the appointment or at another date, the dentist and hygienist will proceed as follows:</strong></p>\n\n<ul>\n<li>Performe anesthesia (\"Freezing\"), if going far bellow the gums, which allows the scalling and root planing (S&amp;RP - Deep cleaning) of the roots with minimum discomfort to the patient.</li>\n<li>Some clinics have a mouth rinsing protocol to reduce the amount of bacterias preoperatively, to avoid having the bacterias in the aerosols produced by the cleaning. <strong>I don't have literature that supports the assumed purpose of this intervention. The fastest way would be to simply ask your dentist.</strong></li>\n<li>Use a water-cooled ultrasonic scaler (for instance Cavitron®) to break up most of the calculus. This shortens the appointment times considerably, but produces aerosols which may contain bacteria.\n<a href=\"https://i.stack.imgur.com/uxch7.png\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/uxch7.png\" alt=\"Cavitron® universal tip\"></a></li>\n<li><strong>Use manual hand-instruments such as curettes to remove any remaining calculus on and in-between the teeth</strong>.\n<a href=\"https://i.stack.imgur.com/fuYh9.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/fuYh9.jpg\" alt=\"Gracey® Curettes, of various calibres and angulations\"></a></li>\n<li>Use an abrasive past to perform prophylactic (preventive) smoothing and polishing of the teeth surfaces. This step is necessary to discourage plaque from latching onto the freshly scaled surfaces, which can be rough at the microscopic level. This makes your home care more efficient too and can help decrease the frequency of appointments. If the previous 2 steps were done, this should take a minimal amount of time.</li>\n</ul>\n\n<p>If severe gum disease is already present or for whatever reason the attempts at nonsurgical therapy are unsuccessful, a Surgical therapy can be planned and initiated, but this goes beyond the scope of your original question.</p>\n\n<p>For a more in-depth look at basic and non-surgical periodontal care, one can look at the following article: <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/11155183\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/pubmed/11155183</a></p>\n\n<p><em>N.B.: This is a general explanation of what is done in dentistry, and should not be taken as a treatment plan specifically for you or anybody else, as per Health.SE rules.</em></p>\n", "score": 7 } ]
16,330
CC BY-SA 4.0
What procedures do dentists use for cleaning teeth, is there variation, and what is the rationale?
[ "dentistry" ]
<p>I am curious if there is a standard regimen that a dentist uses for cleaning teeth, how standardized it is, and what is the rationale for that process over say some other. </p> <p>The process my dentist seems to use is to ask me to swig with peroxyl swish it around for 30 seconds and then spit it out. What's going on with that? </p> <p>Then he/she tends to scrape up and down <em>between</em> the teeth as an inspection of how much tartar has been built up. Then with a water rinse he scrapes specific areas and uses a cavitron machine/water pick like thing, but I think there two he/she is mostly working in between the surfaces. This tool also has access to the back of the teeth.</p> <p>Then finally does he apply toothpaste, and again he applies to the the back of the teeth as well as front. The time spent on this phase seems pretty small in contrast to the time with scraping the teeth either with a dental tool or the cavitron.</p> <p>Is this standard? Any thoughts on why this process or another one?</p> <p><strong>Notes regarding the accepted answer:</strong> </p> <p>Although the accepted answer is informative and detailed, it focuses on the "periodontal" aspects, which doesn't cover the part at the beginning where the dentists asks me to rinse my mouth, sometimes with water or with some bluish stuff that when I asked was called peroxyl. Nor the part where he/she applies toothpaste. I believe most dentists as part of their routine do something with the swish at the beginning, and toothpaste. Also, dentists periodically take xrays to look for cavities.</p> <p>The answer is also a little light on the benefit of each of the steps, or why things are done in that order if it matters. One can kind of read between the lines to infer why each step might be useful and why a particular step might be done before another. Part of understanding and improving such process requires a little understanding and introspection of what needs to be done, how each step achieves that, and what are the alternative ways to achieve the various goals.</p> <p>There can be a bit of fuzziness (if not a lack of critical thought) when it comes to dental processes and explanations. </p>
7
https://medicalsciences.stackexchange.com/questions/16358/what-is-the-difference-between-free-sugars-and-non-free-sugars-both-chemically
[ { "answer_id": 16359, "body": "<h2>TL;DR</h2>\n\n<p>Free sugars are all instances were sugar can be avoided and is not essential. It is encouraged to cut down the free sugars intake because sugar has many negative health effects:</p>\n\n<p>Sugar</p>\n\n<ul>\n<li>increases the risk of obesity</li>\n<li>is linked to diabetes</li>\n<li>is linked to fatal cardiovascular disease</li>\n<li>encourages caries</li>\n<li>is linked to the Alzheimer’s disease</li>\n<li>is linked to ADHD</li>\n</ul>\n\n<hr>\n\n<blockquote>\n <p>There is a wealth of evidence from many different types of investigation, including human studies, animal experiments and experimental studies in vivo and in vitro to show the role of dietary sugars in the etiology of dental caries (21). Collectively, data from these studies provide an overall picture of the cariogenic potential of carbohydrates. Sugars are undoubtedly the most important dietary factor in the development of dental caries. Here, the term ‘‘sugars’’ refers to all monosaccharides and disaccharides, while the term ‘‘sugar’’ refers only to sucrose. <strong>The term ‘‘free sugars’’ refers to all monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, plus sugars naturally present in honey, fruit juices and syrups.</strong> The term ‘‘fermentable carbohydrate’’ refers to free sugars, glucose polymers, oligosaccharides and highly refined starches; it excludes non-starch polysaccharides and raw starches.</p>\n \n <p><sup>Source: <em>Joint WHO/FAO Expert Consultation, 2003</em>, \"<strong><a href=\"http://apps.who.int/iris/bitstream/handle/10665/42665/WHO_TRS_916.pdf;jsessionid=F07A1857FEE48931A02F354C88EB2AF3?sequence=1\" rel=\"nofollow noreferrer\">WHO Technical Report Series 916 Diet, Nutrition, and the Prevention of Chronic Diseases</a></strong>\", Geneva. 2003, p.109, Emphasis Mine</sup></p>\n</blockquote>\n\n<p>Semantically, the main difference is that <em>free sugars</em> are refined, and non-free sugars are unrefined. This is not really a chemical difference in the molecule (refined glucose is still glucose), but rather in the process of manufacturing products and foods. </p>\n\n<p><a href=\"https://www.webmd.com/food-recipes/features/health-effects-of-sugar\" rel=\"nofollow noreferrer\">The medical effects of free sugar are the same as of non-free sugar</a> - glucose is glucose no matter what fancy name you give it and where you put it.</p>\n\n<p>But free sugar is mostly a food additive and not essential: Carbohydrates and starches are unavoidable, but adding household sugar or honey to foods as additives is unnecessary:</p>\n\n<blockquote>\n <p>Free sugars* contribute to the overall energy density of diets and higher intakes of free sugars threaten the nutrient quality of the diet by providing significant energy without specific nutrients, leading to unhealthy weight gain and increased risk of obesity and various NCDs, particularly dental caries which is the most prevalent NCD globally.</p>\n \n <p><sup>Source: WHO.gov. <strong><a href=\"http://www.who.int/elena/titles/free-sugars-adults-ncds/en/\" rel=\"nofollow noreferrer\">Reducing free sugars intake in adults to reduce the risk of noncommunicable diseases</a></strong></sup></p>\n</blockquote>\n\n<p>Other negative health effects of free sugar are summarised here:</p>\n\n<blockquote>\n <p>Free sugars contribute to the overall energy density of diets, and may\n promote a positive energy balance (5-7). Sustaining energy balance is\n critical to maintaining healthy body weight and ensuring optimal\n nutrient intake (8). <strong>There is increasing concern that intake of free\n sugars – particularly in the form of sugar-sweetened beverages –\n increases overall energy intake and may reduce the intake of foods\n containing more nutritionally adequate calories, leading to an\n unhealthy diet, weight gain and increased risk of NCDs</strong> (9-13). Another\n concern is the <strong>association between intake of free sugars and dental\n caries</strong> (3, 4, 14-16). Dental diseases are the most prevalent NCDs\n globally (17, 18) and, although great improvements in prevention and\n treatment of dental diseases have occurred in the past decades,\n problems still persist, causing pain, anxiety, functional limitation\n (including poor school attendance and performance in children) and\n social handicap through tooth loss. The treatment of dental diseases\n is expensive, consuming 5–10% of health-care budgets in industrialized\n countries, and would exceed the entire financial resources available\n for the health care of children in most lower income countries (17,\n 19).</p>\n \n <p><sup>Source: WHO. <strong><a href=\"http://apps.who.int/iris/bitstream/handle/10665/149782/9789241549028_eng.pdf?sequence=1\" rel=\"nofollow noreferrer\">Sugars intake for adults and children</a></strong>. p.1, Emphasis Mine</sup></p>\n</blockquote>\n\n<p>Furthermore, <a href=\"https://www.health.harvard.edu/blog/eating-too-much-added-sugar-increases-the-risk-of-dying-with-heart-disease-201402067021\" rel=\"nofollow noreferrer\">eating too much added sugar increases the risk of dying with heart disease (Harvard Health Blog)</a> and is correlated to ADHD development.</p>\n\n<blockquote>\n <p>In the past decade, we have become increasingly aware of strong associations between overweight/obesity and symptoms of attention-deficit/hyperactivity disorder (ADHD) in children, adolescents, and adults. </p>\n \n <blockquote>\n <p><sup>Source: Davis, Caroline: <strong><a href=\"https://link.springer.com/article/10.1007%2Fs11920-010-0133-7\" rel=\"nofollow noreferrer\">Attention-deficit/Hyperactivity Disorder: Associations with Overeating and Obesity</a></strong>. 2010\n </blockquote>\n</blockquote>\n\n<p>Last but not least, <a href=\"https://nutritionj.biomedcentral.com/articles/10.1186/1475-2891-12-114\" rel=\"nofollow noreferrer\">links between sugar intake and the Alzheimer’s Disease have been found.</a></p>\n\n<p>The only good news is that the current consensus regarding sugar addiction is that sugar is not addictive for humans:</p>\n\n<blockquote>\n <p>We find little evidence to support sugar addiction in humans, and findings from the animal literature suggest that addiction-like behaviours, such as bingeing, occur only in the context of intermittent access to sugar. These behaviours likely arise from intermittent access to sweet tasting or highly palatable foods, not the neurochemical effects of sugar.</p>\n \n <p>Source: <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5174153/\" rel=\"nofollow noreferrer\">Sugar addiction: the state of the science</a></sup></p>\n</blockquote>\n", "score": 9 }, { "answer_id": 16399, "body": "<p>Imagine that your arteries are hallways and that your muscle cells are apartments with doors withing those hallways.</p>\n\n<p>When glucose enters your bloodstream, the body says, \"Hey pancreas! There is energy in the hallways, I need insulin!\" Imagine insulin like agents who come and unlock the doors. The energy then gets into your muscle cells and you are full of energy.</p>\n\n<p>That's what happens when everything works well.</p>\n\n<p><a href=\"https://i.stack.imgur.com/ofUuI.jpg\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/ofUuI.jpg\" alt=\"Arteries the Hallways and Doors the Muscle Cell Doors\"></a></p>\n\n<p>What happens when too much glucose enters your bloodstream too quickly? The body says, \"Hey Pancreas! I need insulin immediately!\". Pancreas says, \"How much boss?\" The body demands, \"Millions within minutes!\" Pancreas replies, \"What?! I can't do that!\" So it tries to create as many insulin agents as possible, but it's not enough.</p>\n\n<p>here aren't enough insulin agents to unlock the doors so too much energy ends up in the bloodstream. And we can't have any of that. So the body goes to plan B. It releases some of it through urine and converts some of it to fat. That's Diabetes type 1.</p>\n\n<p>There is another scenario. Energy enters the bloodstream. Pancreas is working great. There are enough insulin agents, but they can't get to the doors. The doors are blocked by garbage so that the agents can't even reach the handle. What is this garbage? It's fat. It piles up on the apartment doors and prevents insulin agents can't get to it. That's Diabetes type 2. (<a href=\"https://nutritionfacts.org/video/what-causes-insulin-resistance/\" rel=\"nofollow noreferrer\">1</a>) </p>\n\n<p>How does too much glucose enter the bloodstream too quickly? When we consume foods that contain carbohydrates which are deprived of all or almost all fiber. You see, fiber are like traffic controllers who control how fast energy is absorbed into the bloodstream.</p>\n\n<p>If the sugar is bound to fiber, then the traffic controllers do its work. If not, then it's like opening the borders and letting everyone run through without any order. This causes chaos in the bloodstream.</p>\n\n<p>Free sugars are sugars which are not bound to fiber the traffic controllers. Non free sugars are sugars bound to fiber and this is sugar which is consumed when you eat whole fruits and vegetables. No juicing!</p>\n", "score": 1 } ]
16,358
CC BY-SA 4.0
What is the difference between free sugars and non-free sugars, both chemically and medically?
[ "nutrition", "carbohydrates" ]
<p><strong>Background</strong></p> <p>On this <a href="http://www.who.int/en/news-room/fact-sheets/detail/healthy-diet" rel="nofollow noreferrer">WHO entry </a> I read that free sugars must be limited in our diet. The limit is around 5% of the carbohydrates intake.</p> <p>Firstly, I'm quite confused with the difference between <em>free</em> and <em>non free</em> sugars. I would guess it is related to mono and polysaccharides. More I supposed glucose would be a great nutrient as we need lot of carbohydrates, and it is ready for glucolysis. </p> <p><a href="https://youtu.be/xyQY8a-ng6g" rel="nofollow noreferrer">Also the brain needs about 20% of carbohydrates intake</a> - again I can't see why not glucose. In short: I cant understand what's the problem with free sugars.</p> <p><strong>Question</strong></p> <p>On this context I wonder:</p> <p>What is the difference of <em>free</em> and <em>non free</em> sugars? And <strong>why not to eat directly glucose</strong>?</p>
7
https://medicalsciences.stackexchange.com/questions/16460/what-medical-tests-a-man-should-take-regularly-to-check-for-common-health-issues
[ { "answer_id": 16727, "body": "<p>Tests that one may want to do <strong>annually:</strong> </p>\n\n<ul>\n<li><a href=\"http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/KnowYourNumbers/Understanding-Blood-Pressure-Readings_UCM_301764_Article.jsp#.WzYb9NUzZpg\" rel=\"nofollow noreferrer\">Blood pressure</a>; increased BP is a risk factor for heart disease</li>\n<li><a href=\"https://www.cancer.org/cancer/skin-cancer/prevention-and-early-detection/skin-exams.html\" rel=\"nofollow noreferrer\">Checking your skin for moles</a>, which can develop into cancer</li>\n<li><a href=\"https://oregon.providence.org/our-services/l/lipid-profile-cholesterol-and-triglycerides/\" rel=\"nofollow noreferrer\">Blood cholesterol and triglycerides (lipid profile)</a>; increased levels are risk factors for coronary heart disease</li>\n<li><a href=\"https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/blood-sugar/art-20046628\" rel=\"nofollow noreferrer\">Blood glucose</a> to check for diabetes mellitus</li>\n<li>Dental check for caries</li>\n<li>Eye examination</li>\n<li><a href=\"https://www.cancer.gov/types/prostate/psa-fact-sheet\" rel=\"nofollow noreferrer\">PSA test</a> for prostate cancer</li>\n<li>Fecal blood test, colonoscopy and other <a href=\"https://www.cancer.org/cancer/colon-rectal-cancer/detection-diagnosis-staging/screening-tests-used.html\" rel=\"nofollow noreferrer\">tests for colorectal cancer</a> ( for those with a family history of colorectal cancer)</li>\n<li>Computed tomography or other <a href=\"https://www.cdc.gov/cancer/lung/basic_info/screening.htm\" rel=\"nofollow noreferrer\">tests for lung cancer</a> (for smokers)</li>\n</ul>\n\n<p>I'm not aware of any recommendation for <strong>monthly</strong> tests for healthy men.</p>\n", "score": 2 } ]
16,460
CC BY-SA 4.0
What medical tests a man should take regularly to check for common health issues?
[ "test", "male", "andrology" ]
<p>What medical tests should a man living in a relatively developed area take regularly to check for most common diseases? I'm interested in <strong>monthly</strong> and <strong>yearly</strong> basis.</p>
7
https://medicalsciences.stackexchange.com/questions/16505/does-elevated-potassium-lead-to-elevated-cortisol
[ { "answer_id": 16513, "body": "<p>National Institutes of Health - Health Professionals Fact Sheet on Potassium</p>\n<blockquote>\n<p><strong>Dietary potassium</strong></p>\n<p>In healthy people with normal kidney function, high dietary potassium intakes do not pose a health risk because the kidneys eliminate excess amounts in the urine. In addition, there is no evidence that high intakes of dietary potassium have adverse effects. Therefore, the Food and Nutrition Board did not set a UL for potassium.</p>\n<p><sup>Source: National Institutes of Health - <a href=\"https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/#h8\" rel=\"nofollow noreferrer\">Health Professionals Fact Sheet on Potassium, Health Risks from Excessive Potassium</a></sup></p>\n</blockquote>\n<p>Note, the article speaks of dietary potassium, what we would consume in the diet.</p>\n<p>A lot of sites on the internet make the (dubious?) assumption that all persons are under the care of a doctor, and hence they would know if they had inadequate kidney function. But of course, for various reasons, not everyone is under the care of a doctor.</p>\n<p>Nevertheless, I hope the above information is helpful. I would suggest that people may want to read the entire article on potassium that I linked.</p>\n", "score": 3 }, { "answer_id": 31014, "body": "<p>&quot;Does potassium really raise cortisol? Are there any published research articles confirming this?&quot;</p>\n<p>My google search &quot;effects of potassium intake on cortisol&quot; brought up:</p>\n<p><a href=\"https://pubmed.ncbi.nlm.nih.gov/33870711/\" rel=\"nofollow noreferrer\">Dreier et al.,</a> Effect of Increased Potassium Intake on Adrenal Cortical and Cardiovascular Responses to Angiotensin II: A Randomized Crossover Study, J Am Heart Assoc. 2021:</p>\n<p>&quot;... Increased potassium intake lowers blood pressure in patients with hypertension, but increased potassium intake also elevates plasma concentrations of the blood pressure-raising hormone <em>aldosterone</em>.</p>\n<p>This argues for aldosterone, not cortisol, being the hormone that does react to potassium intake. That should be accepted knowledge.</p>\n<p>My search found only one other study:</p>\n<p><a href=\"https://www.sciencedirect.com/science/article/abs/pii/S0041008X07000531?via%3Dihub\" rel=\"nofollow noreferrer\">Li/Lin</a>, Interacting influence of potassium and polychlorinated biphenyl on cortisol and aldosterone biosynthesis, Toxicology and Applied Pharmacology\nVolume 220, Issue 3, 1 May 2007, Pages 252-261:\n&quot;Giving human adrenocortical H295R cells 14 mM <em><strong>KCl</strong></em> for 24 h significantly induced <em><strong>not only aldosterone</strong></em> biosynthesis <em><strong>but also cortisol biosynthesis</strong></em>. Pre-treating the cells with polychlorinated biphenyl 126 (PCB126) further increased potassium-induced aldosterone and cortisol productions in a dose-dependent manner, ...&quot;</p>\n<p>From both quotes you might infer that as a principle it is acknowledged that high potassium intake is able to increase aldosterone, and that it comes to a surprise to find out the same for cortisol.</p>\n<p>Interestingly, both hormones seem to be relevant with Addison's disease (which is primarily known for not enough cortisol only), whereas with Cushing's disease (i.e. too much cortisol) it's only the cortisol. Cp. Wikipedia on <a href=\"https://en.wikipedia.org/wiki/Addison%27s_disease\" rel=\"nofollow noreferrer\">Addison's disease</a>: &quot;... endocrine disorder characterized by inadequate production of the steroid hormones cortisol and aldosterone...&quot;, and on <a href=\"https://en.wikipedia.org/wiki/Cushing%27s_syndrome\" rel=\"nofollow noreferrer\">Cushing's</a>: Aldosterone/potassium not mentioned. However, there seem to be cases to be classified as Cushing's that involve both hormones, see <a href=\"https://bmcendocrdisord.biomedcentral.com/articles/10.1186/s12902-019-0395-y\" rel=\"nofollow noreferrer\">Ren et al.</a>, Hypercortisolism and primary aldosteronism caused by ... adenomas ..., 2019,&quot;...Herein, we report a patient with co-existing cortisol-producing and aldosterone-producing adrenocortical adenomas, one in each adrenal gland. ...&quot;. On the other hand, <a href=\"https://en.wikipedia.org/wiki/Primary_aldosteronism\" rel=\"nofollow noreferrer\">Conn's syndrome</a> is defined by too much aldosterone, and cortisol not involved.</p>\n<p>Here's my personal hint to it: All this might mnemonically be reconciled by tentatively hypothesizing for the sake of learning that, as cortisol is the first and only hormone to regulate blood pressure after waking up (levels are high in the morning) to raise blood pressure, thus indirectly raising renal filtration and at the same time renal reabsorption. There seems no more than only basic accepted knowledge about the issue of potassium excretion and reabsorption: potassium is freely filtrated, and it is reabsorbed via cells by so called Na+/K+-ATPase (proximal tubuli; to distinguish from the aldosterone exchange of potassium excreted against sodium). Try some search on &quot;cortisol potassium renal reabsorption&quot;: the role of cortisol mediated blood pressure on reabsorption of potassium (and sodium) is rather unclear, and it seems no more than a theoretical possibility that cortisol has some direct effect on Na+/K+-ATPase. If yes, that should argue in favour of my own personal approach to Li/Lins's paper: Could surprisingly found increase of cortisol be caused by increase of aldosterone and excessive excretion of potassium (coupled with excessive reabsorption of sodium)? Reabsorption of NaCl, known to be used for plasma expansion, might lead to a rise of cortisol and cortisol induced filtration. Conn's disease (too much aldosterone, no cortisol involved, i.e. contrary to the above no rise in cortisol from reabsorption of potassium) can be differentiated against the findings of the cited study: With Conn's there is no elevated potassium <em>intake</em> (wording of your question). Mnemonically, one might even look upon polychlorinated biphenyl as a functional equivalent of NaCl in that sense (blood volume and pressure).</p>\n<p>The above thus tries to reconcile the findings of that single study with traditional knowledge that &quot;elevated potassium&quot; (your question) does not &quot;lead to elevated cortisol&quot; (according to the above: potassium does not raise blood pressure).</p>\n<p>The source your question refers to (&quot;Selfhacked&quot;) might have - erroneously maybe - not only have exchanged cause and effect but also high and low (to make it right...) as (something Wikipedia on Cushing's does not mention) low potassium levels are known effects of high cortisol levels.</p>\n<p>See some bing search about this (not some standard knowledge, I guess)</p>\n<p><a href=\"https://www.bing.com/search?q=potassium%20cushing&amp;PC=U316&amp;FORM=CHROMN\" rel=\"nofollow noreferrer\">https://www.bing.com/search?q=potassium+cushing&amp;PC=U316&amp;FORM=CHROMN</a></p>\n<p>Cortisol seems to be cause not effect in respect of the regulation of blood pressure and blood sugar, both of which might relate to potassium level (effect not cause):</p>\n<p>About the issue of potassium and blood sugar see, e.g., this video on <a href=\"https://www.bing.com/videos/search?q=insuline%20potassium%20blood&amp;docid=608004195014698940&amp;mid=60F2C95D6B9B08A87E2260F2C95D6B9B08A87E22&amp;view=detail&amp;FORM=VIRE\" rel=\"nofollow noreferrer\">Insuline and potassium relationship</a>. Again, potassium level is considered not cause but effect.</p>\n<p>About cause and effect in the context not of blood sugar but blood pressure see, e.g., <a href=\"https://my.clevelandclinic.org/health/articles/22187-cortisol\" rel=\"nofollow noreferrer\">How does cortisol regulate blood pressure?</a></p>\n<p>&quot;...The exact way in which cortisol regulates blood pressure in humans is unclear. However, elevated levels of cortisol can cause high blood pressure, and lower-than-normal levels of cortisol can cause low blood pressure.&quot;</p>\n<p>Maybe the statement you quote is based on the known fact that high potassium levels (potassium consumption) are consistent with low blood pressure, implicitely hypothesizing that low blood pressure then leads to cortisol secretion. Conversely, for blood sugar quoted video's issue shows that raised potassium in blood is consistent with high levels of blood sugar which apparently do not call for a raise in cortisol.</p>\n", "score": 1 } ]
16,505
CC BY-SA 4.0
Does elevated potassium lead to elevated cortisol?
[ "endocrinology", "potassium", "cortisol" ]
<p>I came across <a href="https://www.selfhacked.com/blog/need-know-cortisol-health-effects/" rel="nofollow noreferrer">this statement on Selfhacked</a>: </p> <blockquote> <p>If you have high cortisol, you will do worse with a high salt diet and you will be potassium deficient in the long term (few people as it is get the RDA). But taking potassium supplements is not simple, because the deficiency is in your cells, not your blood. Also, <strong>potassium raises cortisol</strong>, which isn’t good if you already have high levels. Cortisol is anti-inflammatory, but it can also cause arthritis by inhibiting collagen formation and also by lowering cell potassium. Cell potassium is always low in rheumatoid arthritis (R). The answer is to reduce stress.</p> </blockquote> <p>I tried searching for any proof of this, but haven't been able to find. Is this true? Does potassium really raise cortisol? Are there any published research articles confirming this? </p> <p>Does it follow from this (if true) that a constant overdose of potassium-rich foods may cause a Cushing-like state? This sounds doubtful to me.</p>
7
https://medicalsciences.stackexchange.com/questions/16534/why-do-we-continue-compressions-after-the-first-aed-shock
[ { "answer_id": 16653, "body": "<p>The only thing that keeps a patient in cardiac arrest alive is constant, high-quality chest compression.</p>\n\n<p>Cardioversion (\"shocking\") of a patient aims to return the heart to normal (sinus) rhythm in the case that a cardiac arrest is due to a dysrhythmia. If it works, great - return of spontaneous circulation (ROSC) will be achieved and there will be signs of this; coughing, spluttering, pulse etc.</p>\n\n<p>We assume that it will not be successful and immediately resume compressions because even a couple of seconds delay in chest compressions dramatically reduces organ perfusion and worsens outcome.</p>\n\n<p>A couple of chest compressions in a patient who has been successfully cardioverted will not do any particular harm and the downsides of waiting to see if it has worked are huge.</p>\n", "score": 6 }, { "answer_id": 23703, "body": "<p>There are several studies that emphasize the importance of providing rapid and deep compressions and that CPR should resume immediately after the shock given by the AED, without the delay entailed in checking for pulse or rhythm conversion. </p>\n\n<p>Here is an excerpt from one of the studies:</p>\n\n<p>\"After a successful shock, the rescuer was expected to assess the patient for a return of pulse after conversion of the ventricular rhythm. However, the delivery of repeat shocks (if necessary) and checking of the patient's pulse were found to delay the resumption of CPR for 60 seconds or more. Also, even after conversion, the ventricle was often stunned, so that its effective mechanical function did not return with the resumption of sinus rhythm. These issues, along with the finding that the ventricular rhythm was converted to sinus rhythm with the first shock in 85% of cases (13) led the AHA to modify the algorithm so as to specify only a single shock before immediate resumption of CPR, with a check of the patient's cardiac rhythm and pulse only after 3 minutes of continued compressions (14). This change in the resuscitation guideline, like the elimination of rescue breathing, maximizes the time during resuscitation for chest compressions and thus optimizes efforts to provide tissue perfusion.\"</p>\n\n<p>Sources: </p>\n\n<p><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116356/\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116356/</a></p>\n\n<p><a href=\"https://www.aedusa.com/training\" rel=\"nofollow noreferrer\">https://www.aedusa.com/training</a></p>\n\n<p><a href=\"https://www.ahajournals.org/doi/full/10.1161/circulationaha.105.165674\" rel=\"nofollow noreferrer\">https://www.ahajournals.org/doi/full/10.1161/circulationaha.105.165674</a></p>\n", "score": 4 } ]
16,534
CC BY-SA 4.0
Why do we continue compressions after the first AED shock?
[ "cardiology", "first-aid", "cpr" ]
<p>I just took a CPR course and was instructed to perform 5 cycles of compressions after an AED shock (after which you wait for the AED to do another analysis). My question is: if the shock was successful and the heart started beating again, wouldn't compressions mess with the heart starting up its rhythm?</p>
7
https://medicalsciences.stackexchange.com/questions/16708/should-i-meet-nutritional-recommendations-for-e-g-rdas-daily
[ { "answer_id": 16718, "body": "<p>In short: For most nutrients, you do not need to meet the Recommended Dietary Allowances (RDAs) each day. You could get, for example, 7 RDAs amounts of certain nutrients randomly distributed through 7 days without having any deficiency symptoms.</p>\n\n<p><a href=\"https://ods.od.nih.gov/Health_Information/Dietary_Reference_Intakes.aspx\" rel=\"nofollow noreferrer\">Office of Dietary Supplements, NIH.gov</a>:</p>\n\n<blockquote>\n <p>Recommended Dietary Allowance (RDA): <strong><em>average</em></strong> daily level of intake\n sufficient to meet the nutrient requirements of nearly all (97%-98%)\n healthy people.</p>\n</blockquote>\n\n<hr>\n\n<p><strong>1) Compensatory mechanisms</strong> that can provide the sufficient amount of nutrients on the days you don't get them by food:</p>\n\n<ul>\n<li>The release of nutrients from your <strong>body stores</strong> (glucose from glycogen in the liver, fat from body fat, proteins from <strong><a href=\"http://chemistry.elmhurst.edu/vchembook/630proteinmet.html\" rel=\"nofollow noreferrer\">liver and blood proteins</a>,</strong> vitamins from the liver, calcium and phosphorus from bone, etc.) </li>\n<li>The <strong><a href=\"http://healthyeating.sfgate.com/intimate-relationship-between-protein-fat-5844.html\" rel=\"nofollow noreferrer\">conversion of carbohydrates, proteins and fats into each other</a></strong> in your body</li>\n<li><strong>Retaining minerals,</strong> such as <strong><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4455213/\" rel=\"nofollow noreferrer\">potassium</a>,</strong> by the kidneys</li>\n</ul>\n\n<p><strong>2) For how long can you skip the intake of a certain nutrient without having any deficiency symptoms?</strong></p>\n\n<ul>\n<li><strong>Carbohydrate</strong> stores (in the form of glycogen) last for 1-2 days after you stop consuming them. After that, carbohydrates can be produced in your body from fats and proteins. Theoretically, <strong><a href=\"https://www.nap.edu/read/10490/chapter/8#275\" rel=\"nofollow noreferrer\">you do not need to get any carbohydrates</a></strong> from food for any period of time because they can be all produced in your body.</li>\n<li><strong>Proteins</strong> in the liver and blood represent an <strong><a href=\"http://chemistry.elmhurst.edu/vchembook/630proteinmet.html\" rel=\"nofollow noreferrer\">amino acid pool</a>,</strong> which can be used to create new proteins, as needed, for at least few days after stopping consuming proteins. </li>\n<li>For how long you can go without <strong>fats,</strong> mainly depends on your body fat stores as mentioned in this <strong><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495396/pdf/postmedj00315-0056.pdf\" rel=\"nofollow noreferrer\">382 days fasting study</a>.</strong></li>\n<li>The stores of <strong>water-soluble vitamins (B complex, <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2567249/\" rel=\"nofollow noreferrer\">C</a>)</strong> should be enough for 1-2 months, in most cases, but <strong><a href=\"http://www.who.int/nutrition/publications/en/thiamine_in_emergencies_eng.pdf\" rel=\"nofollow noreferrer\">vitamin B1</a></strong> stores could last for only 2-3 weeks.</li>\n<li>The stores of <strong>vitamins <a href=\"http://extension.colostate.edu/topic-areas/nutrition-food-safety-health/fat-soluble-vitamins-a-d-e-and-k-9-315/\" rel=\"nofollow noreferrer\">A</a>, <a href=\"https://medlineplus.gov/ency/article/002403.htm\" rel=\"nofollow noreferrer\">B12</a> and <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4768118/\" rel=\"nofollow noreferrer\">E</a></strong> could be enough for 2 years or more.</li>\n<li>You could probably go without most <strong>minerals</strong> for at least 1 month according to the abovementioned fasting study.</li>\n</ul>\n", "score": 3 } ]
16,708
CC BY-SA 4.0
Should I meet nutritional recommendations (for e.g., RDAs) daily?
[ "nutrition" ]
<p>For example, the recommended daily protein intake is 0.8g per kilogram of body weight. So, let's say that I take more than required on a given day and less than required on an another day -- is that okay? I'm not asking about eating all the protein you need one day and nothing at all for the rest of week, but what about tiny fluctuations? What if you meet 50% of your daily recommendation one day but compensate for it the next couple of days?</p> <p>How does that work for other nutrients such as vitamins and minerals? Does our body somehow 'store' these nutrients when you take in more than what is necessary?</p>
7
https://medicalsciences.stackexchange.com/questions/16919/how-does-breastfeeding-protect-the-mothers-bones
[ { "answer_id": 18594, "body": "<p>I can understand your confusion, since the literature has confounding data. However, I would suggest that you expand your reasoning beyond only thinking about calcium demand and consider hormonal changes as well. Regardless, a newer paper that recently came out from <a href=\"https://doi.org/10.1007/s00198-015-3292-x\" rel=\"noreferrer\">Hwang et al. (2016)</a> has some great information. They cite the papers that have shown protective effects as well as the papers that show deleterious effects. It is a complex issue, since the length of time of the breastfeeding matters as well as past and present medical history; it would be important to correct for differences in exercise, smoking, and diet; and age of breastfeeding as well as age of menarche are important as well.</p>\n<h2>References</h2>\n<p>Hwang, I. R., Choi, Y. K., Lee, W. K., Kim, J. G., Lee, I. K., Kim, S. W., &amp; Park, K. G. (2016). Association between prolonged breastfeeding and bone mineral density and osteoporosis in postmenopausal women: KNHANES 2010-2011. Osteoporosis International, 27(1), 257–265. <a href=\"https://doi.org/10.1007/s00198-015-3292-x\" rel=\"noreferrer\">https://doi.org/10.1007/s00198-015-3292-x</a></p>\n", "score": 6 } ]
16,919
CC BY-SA 4.0
How does breastfeeding protect the mother&#39;s bones?
[ "nutrition", "bones", "breastfeeding", "calcium" ]
<p>Every time that I look up breastfeeding benefits for the mom I get these main 3 along with others:</p> <ul> <li>Decreased chance of breast cancer</li> <li>Decreased chance of ovarian cancer</li> <li><strong>Decreased chance of osteoporosis(put another way, increased bone density)</strong></li> </ul> <p>This seems counter intuitive though, not the cancer protection but the osteoporosis protection. Your body takes calcium from your bones when calcium is in increased demand. Typically a mom won't eat enough calcium to prevent this bone breakdown. In pregnant women this is significant because you have an unborn baby inside you whose bones are being ossified. </p> <p>But it would seem to me that breastfeeding would also increase the bodily demand for calcium because an ounce of breastmilk contains 10 mg of calcium and a breastfeeding woman can produce up to a liter of breastmilk a day. That is 33.814 ounces or 338 mg of calcium for enough breastmilk to feed the mom's baby/babies. That is a lot of calcium just for breastfeeding. Not to mention that the needed intake for anyone between 18-50 is 1000 mg of calcium. This means with the calcium needed for breastmilk production, you get a net intake of around 750 mg of calcium. That is a net deficiency so you get bone breakdown.</p> <p>So it would make sense then that the ideal calcium intake for a breastfeeding woman would be 1350 mg of calcium due to the amount of calcium in breastmilk and the fact that a woman can produce up to a liter of breastmilk in 1 day. That way you don't end up with bone breakdown.</p> <p>So if up to 338 mg of calcium goes into making breastmilk, why do breastfeeding women with an intake of 1000 mg of calcium which is what is needed for the average 18-50 year old human, not get osteoporosis but instead increased bone density? Do oxytocin and prolactin somehow divert more calcium towards bone(like do they increase active vitamin D levels) to offset the fact that about a third of the calcium that is needed is diverted to the breasts for milk production?</p> <p>Because I don't see how you could possibly end up with an increase in bone density when 1/3 of your required calcium is diverted into breastmilk for the baby.</p>
7
https://medicalsciences.stackexchange.com/questions/17210/how-to-deal-with-conflicting-health-advice
[ { "answer_id": 17214, "body": "<p>The best method to verify the autenticity of a scientific news, is to search authorized papers about the subject.</p>\n\n<p>You can find all the published papers on this website: <a href=\"https://www.ncbi.nlm.nih.gov/\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/</a></p>\n\n<p>Here, and especially on \"PubMed\" and \"PubMed Central (PMC)\" (both within ncbi.gov) you can search for a topic and a lot of papers will be shown. Then look for the most recent one, since sometimes newer reviews discover something important. </p>\n\n<p>In your case, this can be a good starting point.</p>\n", "score": 4 } ]
17,210
CC BY-SA 4.0
How to deal with conflicting health advice?
[ "nutrition", "diet", "research" ]
<p>With all the information on health how can I know who is accurate?</p> <p>Healthline ( <a href="https://www.healthline.com/nutrition/saturated-fat-good-or-bad#section5" rel="noreferrer">7</a> ) claims that saturated fat is not bad for you while Harvard ( <a href="https://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good" rel="noreferrer">6</a> ) claims it is a bad fat.</p>
7
https://medicalsciences.stackexchange.com/questions/17246/when-is-too-much-running-bad-for-your-health
[ { "answer_id": 17255, "body": "<p>The consensus view is <a href=\"https://www.merckmanuals.com/professional/cardiovascular-disorders/sports-and-the-heart/athlete%E2%80%99s-heart\" rel=\"nofollow noreferrer\">given here</a>. So, the views of James O'Keefe are not widely accepted in the medical community. Suppose, however, that the adverse effects of strenuous long endurance exercise he argues for, will be rigorously established. Even then, there is still an issue with the diet as a confounding variable.</p>\n\n<p>According to O'Keefe, the U-shaped curve is supposed to go up again somewhere around 40 minutes of running at 12 km/h, But at that level of exercise, you need to eat significantly more than people who just run for a few miles at a slower pace, as he is suggesting is much healthier. A rule of thumb is that an hour of running at a pace of 12 km/h burns 1000 Kcal, but this will also depend on the weight of the person, whether you run of flat terrain etc.</p>\n\n<p>Burning 1000 Kcal means that you must be eating 1000 Kcal more, which raises two issues. The first is whether you are going to eat that extra 1000 Kcal in the form of unhealthy high energy density foods. We can address this first issue by investigating the diets. Based on the results we can then correct for e.g. an average drift toward unhealthier diets by people who burn more calories.</p>\n\n<p>But there exists another problem with the diet that is then not corrected for. Suppose that the diet of most people, regardless of exercise intensity, is actually a cause of cardiovascular disease. This is a real possibility, given e.g. the results of <a href=\"https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(17)30752-3/fulltext\" rel=\"nofollow noreferrer\">this recent study</a>. One can find a similar conclusion also in <a href=\"https://academic.oup.com/ije/article/41/5/1221/712631\" rel=\"nofollow noreferrer\">this much older study</a> (note that the linked article is to a recent reprint, the original author <a href=\"https://academic.oup.com/ije/article/41/5/1225/712708\" rel=\"nofollow noreferrer\">comments here about this old research</a>). Then it's entirely natural to find a U-shaped curve if exercise by itself is beneficial well above the limits O'Keefe is arguing for, because you'll obviously get some level of diminished returns from exercise more and more, while the adverse effects of the diet will increase with the increased calorie intake, without flattening off. </p>\n", "score": 3 } ]
17,246
CC BY-SA 4.0
When is too much running bad for your health?
[ "exercise", "health-education", "heart" ]
<p>In <a href="https://www.youtube.com/watch?v=Y6U728AZnV0" rel="nofollow noreferrer">this ted talk</a>, cardiologist <a href="https://en.wikipedia.org/wiki/James_O%27Keefe_(cardiologist)" rel="nofollow noreferrer">James O'Keefe</a> argues that intensive running is bad for your heart. This conclusion is pretty alarming to me, and counter to what I have always thought. Is there a consensus among the medical community that too much running can be detrimental to your health? If so, under what circumstances? I can understand that extreme distance runners could be doing too much, but what about short distance runners? Do I need to be concerned about high intensity, short distance (say 2-8 miles) runs?</p>
7
https://medicalsciences.stackexchange.com/questions/17300/is-it-possible-for-obesity-to-occur-as-a-result-of-medical-conditions-and-not-ju
[ { "answer_id": 17305, "body": "<p>As far as medical conditions, it could be a thyroid problem, or the need to encourage serotonin, and I am sure many other things a doctor would know about so ask a doctor. </p>\n\n<p>Another article: magnesium &amp; obesity <a href=\"https://pubag.nal.usda.gov/pubag/downloadPDF.xhtml?id=46295&amp;content=PDF\" rel=\"nofollow noreferrer\">https://pubag.nal.usda.gov/pubag/downloadPDF.xhtml?id=46295&amp;content=PDF</a> People should be aware it is calcium, Vitamin D ratio with magnesium! Vitamin D can overwork magnesium to metabolize vitamin D and we have people taking some high doses of vitamin D. Most Americans get too much calcium in ratio to magnesium. Etc. Bottom line, most people need more magnesium through diet preferably, and probably supplements too. <a href=\"https://www.sciencedaily.com/releases/2018/02/180226122548.htm\" rel=\"nofollow noreferrer\">https://www.sciencedaily.com/releases/2018/02/180226122548.htm</a>. People with kidney disease should ask a doctor before taking a magnesium supplement. Always tell your doctor about the supplements you are taking at each visit, if any; very important. </p>\n", "score": 2 } ]
17,300
CC BY-SA 4.0
Is it possible for obesity to occur as a result of medical conditions and not just over-eating?
[ "diet", "genetics", "obesity" ]
<p>I am not obese myself as I've always been interested in sports since childhood, and put effort into living a healthy and active lifestyle. However, obesity is clearly a growing issue worldwide (no pun intended) and in a lot of countries it seems to be fast becoming the norm socially to be overweight.</p> <p>Sometimes I see articles or listen to people on TV or radio trying to explain away obesity through unspecified medical conditions, genetics, food additives etc. As a sceptical person, I find these reasons hard to believe when, to my knowledge, the only way for a human body to gain weight is by consuming more calories than is burned off on a regular basis (a calorie surplus).</p> <p>Can anyone explain if it's possible for someone to be overweight or obese and it have a genuine medical explanation, and not simply a consequence of poor diet and/or lifestyle choices. I understand that conditions such as diabetes make it harder for someone to manage their diet, but I wouldn't class this as a reason for being obese in itself (clearly not every diabetic is obese).</p>
7
https://medicalsciences.stackexchange.com/questions/17497/did-science-backtrack-regarding-coffee-causing-dehydration
[ { "answer_id": 17499, "body": "<p><strong>Why it has been long assumed that caffeine or coffee is dehydrating?</strong></p>\n\n<p><strong>Because caffeine is a mild diuretic</strong> - it stimulates water excretion through the kidneys. But the amount of water you consume with caffeinated drinks is usually greater than the amount of water you lose in urine due to caffeine diuretic effect, so there is no net water loss and hence no dehydration.</p>\n\n<p>Also, regular (daily) coffee drinkers will usually quickly (within few days) develop tolerance to caffeine effects including the diuretic effect.</p>\n\n<p>Source 1 (<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/19774754\" rel=\"noreferrer\">PubMed, 2003</a>):</p>\n\n<blockquote>\n <p>Caffeine and related methylxanthine compounds are recognized as having\n a diuretic action...</p>\n \n <p>The available literature suggests that acute ingestion of caffeine in\n large doses (at least 250-300 mg, equivalent to the amount found in\n 2-3 cups of coffee or 5-8 cups of tea) results in a short-term\n stimulation of urine output in individuals who have been deprived of\n caffeine for a period of days or weeks. A profound tolerance to the\n diuretic and other effects of caffeine develops, however, and the\n actions are much diminished in individuals who regularly consume tea\n or coffee. Doses of caffeine equivalent to the amount normally found\n in standard servings of tea, coffee and carbonated soft drinks appear\n to have no diuretic action.</p>\n</blockquote>\n\n<p>Source 2 (<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3886980/\" rel=\"noreferrer\">PubMed, 2014</a>):</p>\n\n<blockquote>\n <p>It is often suggested that coffee causes dehydration and its\n consumption should be avoided or significantly reduced to maintain\n fluid balance...Our data show that there were no significant\n differences across a wide range of haematological and urinary markers\n of hydration status between trials. These data suggest that coffee,\n when consumed in moderation by caffeine habituated males provides\n similar hydrating qualities to water. </p>\n</blockquote>\n\n<p><strong>In conclusion,</strong> the old suggestion that caffeine is dehydrating was due to misinterpretation that increased diuresis automatically results in dehydration. They also overestimated the actual diuretic effect of caffeine.</p>\n", "score": 11 } ]
17,497
CC BY-SA 4.0
Did science backtrack regarding coffee causing dehydration?
[ "caffeine", "medical-myths", "coffee", "dehydration" ]
<p>The question below highlights recent studies that conclude coffee does not necessarily dehydrate. </p> <p><a href="https://medicalsciences.stackexchange.com/questions/4879/is-decaffeinated-coffee-a-diuretic">Is decaffeinated coffee a diuretic?</a></p> <p>Why has it always been assumed otherwise? Perhaps the evidence was based on tests of pure caffeine?</p>
7
https://medicalsciences.stackexchange.com/questions/17644/how-do-the-symptoms-of-viral-tonsillitis-differ-from-bacterial-tonsillitis
[ { "answer_id": 17647, "body": "<p>There is a great deal of both overlap and variability in the symptoms associated with pharyngitis. Many causes can include visible swelling of the tonsils and tonsillar exudate, and so can be classified as tonsillitis.</p>\n\n<p>The usual clinical question here is \"should I treat this sore throat with antibiotics,\" which depends on symptoms, signs, history, and epidemiology. In an otherwise healthy individual, the treatment decision is more about preventing later complications associated with infection than treating the (self-limited) infection itself. In most practices the key question, then, is not just \"is this bacterial or viral\", it is, \"is this Group A Streptococcus (GAS) or not\". There is a good discussion of this issue and the evidence in the <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/22965026\" rel=\"noreferrer\">clinical practice guidelines</a> from the infectious diseases society of America. Of note, there is some argument (see Cecil medicine Ch. 437, in addition to the discussion in the IDSA guidelines) for making the question \"is this Fusobacterium necrophorum, GAS, or something else\". </p>\n\n<p>Now, with that preamble, we can get to the question in your title:</p>\n\n<blockquote>\n <p>How do the symptoms of viral tonsillitis differ from bacterial tonsillitis</p>\n</blockquote>\n\n<p>For an otherwise healthy pediatric or young adult patient in the US who is up to date on vaccinations, there are some useful symptom-based rules of thumb (see both the earlier linked guidelines, and the chapter in Cecil).</p>\n\n<p>From the guidelines, signs and symptoms that strongly suggest viral etiology:</p>\n\n<blockquote>\n <ul>\n <li>Conjunctivitis</li>\n <li>Coryza</li>\n <li>Cough</li>\n <li>Diarrhea</li>\n <li>Hoarseness</li>\n <li>Discrete ulcerative stomatitis</li>\n <li>Viral exanthema</li>\n </ul>\n</blockquote>\n\n<p>Cecil's describes a useful evidence based risk score for deciding whether or not to treat with antibiotics (which is essentially a question re: what is the likelihood that this is group A strep). Each of the following gives 1 point: temperature > 38 C, <em>absence</em> of cough, swollen, tender anterior cervical nodes, tonsillar swelling or exudate, and age 3-14 yrs. Age 15-44 years gives 0 points, age >44 subtracts a point. If the score is 4 or more, you treat with antibiotics. If the score is 2 or 3, you culture the throat and treat if positive. if the score is 0 or 1, you observe. You can examine the evidence for this score <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/15069046\" rel=\"noreferrer\">here</a>.</p>\n\n<p>As the risk score algorithm indicates, one of the possible diagnostic next steps is a throat culture for GAS. There are also tests that detect the presence of antigen. It's important to note (as is discussed in the linked sources), that many patients are pharyngeal carriers of GAS, so detecting GAS may not provide any information about the cause of a particular bout of pharyngitis in general or tonsillitis in particular. There is <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/29554121\" rel=\"noreferrer\">a very good meta-analysis</a> that relates to this point. </p>\n", "score": 9 } ]
17,644
CC BY-SA 4.0
How do the symptoms of viral tonsillitis differ from bacterial tonsillitis
[ "diagnosis", "throat", "tonsillitis" ]
<p>How would a doctor distinguish between viral and bacterial tonsillitis? </p> <p>From what I can tell they have the same symptoms</p> <ul> <li>tender throat</li> <li>swollen tonsils</li> <li>painful swallowing</li> <li>fever </li> </ul> <p>So how exactly do they differ, and what would be the diagnostic process a doctor would employ to confirm which form of tonsillitis a patient has?</p>
7
https://medicalsciences.stackexchange.com/questions/17749/is-lipaemia-the-same-as-hyperlipidemia
[ { "answer_id": 17752, "body": "<p>These are not really synonymous. Despite <a href=\"https://www.wikidoc.org/index.php/Lipaemia\" rel=\"noreferrer\">some sites claiming them to be</a>. Compare <a href=\"https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/hyperlipidemia\" rel=\"noreferrer\">the usage on this site</a>.</p>\n\n<p>Lipaemia is describing lab artifacts, that is roughly too much fat in the blood sample <a href=\"https://www.bmj.com/content/340/bmj.b5530\" rel=\"noreferrer\">that interferes</a> with other tests and measurements.</p>\n\n<p>Hyperlipidemia is what is wanted to get measured in a blood sample, that is lipo-proteins or roughly: cholesterol.</p>\n\n<blockquote>\n <p>Clin Chim Acta. 2013 Mar 15;418:30-2. doi: 10.1016/j.cca.2012.12.029. Epub 2013 Jan 8.\n <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23313055\" rel=\"noreferrer\">Lipaemia: causes, consequences and solutions.</a>\n Walker PL, Crook MA.</p>\n \n <p>The detection of lipaemia in a patient blood sample can be a clinical conundrum as well as an analytical nuisance. With a reported prevalence of 0.7% in all blood samples received for lipid studies its finding has been suggested to be an underappreciated problem <a href=\"https://vascular.org/patient-resources/vascular-conditions/hyperlipidemia\" rel=\"noreferrer\">5</a>. Its presence can have a significant impact on the validity of a number of routine blood tests. The intention of this report is to outline the causes of lipaemia, the clinical and analytical consequences of its presence and some of the tools the laboratory employ to reduce its effects. Both laboratory professionals and clinicians should have an appreciation of the analytical and clinical impact lipaemia may confer on routine biochemistry.</p>\n \n <hr>\n \n <p><a href=\"https://vascular.org/patient-resources/vascular-conditions/hyperlipidemia\" rel=\"noreferrer\">Hyperlipidemia</a><br>\n ALSO CALLED Hypercholesterolemia, familial hypercholesterolemia, elevated cholesterol, elevated cholesterol levels</p>\n \n <p>By Gregory L. Moneta<br>\n Hyperlipidemia is an umbrella term that refers to any of several acquired or genetic disorders that result in a high level of lipids (fats, cholesterol and triglycerides) circulating in the blood. These lipids can enter the walls of arteries and increase your risk of developing atherosclerosis (hardening of the arteries), which can lead to stroke, heart attack and the need to amputate. The risk of atherosclerosis is higher if you smoke, or if you have or develop diabetes, high blood pressure and kidney failure.</p>\n</blockquote>\n", "score": 10 }, { "answer_id": 17751, "body": "<p>Because the context refers to a serum sample, and it sounds like a low quality one, you should use lipemia (or, the british variant lipaemia), not hyperlipidemia. </p>\n\n<p>See <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4071188/\" rel=\"noreferrer\">here</a> for an example of the context where this is used.</p>\n\n<blockquote>\n <p>Hemolysis, icterus, and lipemia (HIL) in patient specimens may interfere with the accurate measurement of various analytes</p>\n</blockquote>\n", "score": 9 } ]
17,749
CC BY-SA 4.0
Is lipaemia the same as hyperlipidemia?
[ "blood", "terminology" ]
<p>I'm translating a Russian text and one of the sentences goes like this:</p> <blockquote> <p>Среди сывороток были образцы с гемолизом и <strong>липемией</strong>.<br> The serum samples contained samples with hemolysis and <strong>lipaemia</strong>. </p> </blockquote> <p>I think that it might be good to translate the word as <strong>hyperlipidemia</strong>, because sometimes Russian authors use dated terminology in their texts, and "hyperlipidemia" is more widely used in English. </p> <p>However, there might be some difference between the two terms of which I could be unaware. Is there any difference, and what might it be? </p>
7
https://medicalsciences.stackexchange.com/questions/17985/how-to-communicate-and-apologise-for-a-medical-error
[ { "answer_id": 17986, "body": "<p>You are right to feel empathy about the situation, and it is good to express empathy to our patients. I applaud you for not letting that get beaten out of you by the difficult training our system puts us through. Keeping the human element in medicine is important not only to our patients but to ourselves and the culture of medicine.</p>\n\n<p>And you are right to seek guidance. GME offices usually prep residents in orientation for how to approach this; it is unfortunate that yours did not. It is important to remember that what you say really does matter, both psychologically and legally.</p>\n\n<p><strong>Talk with your faculty about how they recommend you approach it, and I would specifically seek out the attending with whom you precepted the patient</strong>. Remember, it was their patient too. If you do not feel comfortable talking with that attending because of their personality or attitude, turn to your residency director or faculty advisor - that's what they are there for. There is also going to be a legal consultant for the hospital, and you can ask them advice as well. </p>\n\n<p>But one important distinction is whether <em>you</em> truly made an <em>error</em>, or whether you are experiencing empathy about an unfortunate case of an atypical presentation falling through the cracks of standards of practice. Both are <em>types</em> of errors, but they are distinct, and have very different implications. I'm assuming you feel like you missed diagnosing the SAH when they were under your care, but I also assume that you practiced medicine using usual standards of practice while they were in the ED - e.g. following standard algorithms for when to order head CT after a fall, etc. The sensitivity of those tools are not 100%, but they are often the best tool we have when weighing the risks associated with blasting someone's brain with CT radiation against the likelihood that this particular headache is actually a brain bleed. At a population level, think of the brain cancers from unnecessary CTs these algorithms are preventing by not scanning every headache or bumped head. The decision for an individual case is not easy, which is why these algorithms exist. Consider what really happened, not just with the knowledge of the ultimate result. Hindsight is always 20/20. </p>\n\n<p>And again, don't do this on your own. Plus you can recommend to your residency director to hold a didactics session on communicating medical errors; he/she could invite the legal team to discuss it with the residents. It is an important professionalism topic that should be part of your training.</p>\n\n<p>Some websites with good reading on how to approach discussing errors:</p>\n\n<ul>\n<li><a href=\"https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/760546\" rel=\"nofollow noreferrer\">https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/760546</a></li>\n<li><a href=\"https://acpinternist.org/archives/2014/06/errors.htm\" rel=\"nofollow noreferrer\">https://acpinternist.org/archives/2014/06/errors.htm</a></li>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3662285/\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3662285/</a></li>\n</ul>\n", "score": 10 } ]
17,985
CC BY-SA 4.0
How to communicate and apologise for a medical error
[ "communication" ]
<p>I am currently a resident in an emergency department in a small community hospital. I have just been informed that a patient of mine, whom I discharged from the ED three days ago has just been diagnosed with a subarachnoidal hemorrhage and has been admitted to the ICU.</p> <p>I am deeply affected by this news and I want to present my deepest apologies to the family members.</p> <p>What would be the best way of communicating the medical error? How does one apologise? I was planning on explaining how and why the medical error occurred. Is there anything else I should pay special attention to?</p> <p>(We learn a lot about medical errors during medical school but not a lot about how to communicate with family members when those medical errors have occurred. I hope this question is suitable for this site. Thanks in advance.)</p>
7
https://medicalsciences.stackexchange.com/questions/18038/do-nsaids-relieve-pain-or-is-it-a-byproduct
[ { "answer_id": 18039, "body": "<p>Injury or infection triggers the release of prostaglandins, which can cause pain, fever and inflammation (all of which are direct effects of prostaglandins).</p>\n\n<p><a href=\"https://www.nature.com/articles/nsb0403-233\" rel=\"nofollow noreferrer\">Painkillers and Prostaglandins (Nature)</a>:</p>\n\n<blockquote>\n <p>Prostaglandins are powerful signaling agents in the human body. The\n two-dozen or so members of this family of small lipid messengers\n underpin many profound physiological events — including vasodilation,\n vasoconstriction, bronchoconstriction, platelet activation,\n inflammation, uterine contractions, pain perception and fever.</p>\n</blockquote>\n\n<p><a href=\"https://academic.oup.com/bja/article/87/1/3/304226\" rel=\"nofollow noreferrer\">Mechanisms of inflammatory pain (Academic.oup.com)</a>:</p>\n\n<blockquote>\n <p>prostaglandins contribute to pain by directly activating nociceptors</p>\n</blockquote>\n\n<p>This means that NSAIDs can relieve pain even if there is no inflammation, for example, in tension headache (<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3444224/\" rel=\"nofollow noreferrer\">PubMed</a>).</p>\n", "score": 5 }, { "answer_id": 18042, "body": "<p>The way in that this question is framed looks like a false dichotomy.\nThe very first sentence of a recent book starts with:</p>\n<blockquote>\n<p>NSAIDs are one of the most widely prescribed drugs around the world to treat pain and inflammation.</p>\n</blockquote>\n<p>In treatment we often do want the inflammation to go down if it's overshooting.<br />\nIn treatment we often do want the pain to go down if it's overshooting.</p>\n<blockquote>\n<p>Advances on this area have proved that COX-1 and COX-2 products are involved not only in pain and inflammation but in cancer development as well. In fact, most outstanding advances in the field where discovered when these drugs were tested to prevent gastrointestinal cancer. These advances and knowledge cannot be separated today from the effects of aspirin on the cardiovascular system and on cancer prevention and treatment. In addition aspirin is still being used for the short-term treatment of cold, fever, and pain.</p>\n<p>Angel Lanas: &quot;NSAIDs and Aspirin. Recent Advances and Implications for Clinical Management&quot;, Springer: Switzerland, 2016.</p>\n</blockquote>\n<p>There is no pain-receptor to be treated with anti-pain in this class of drugs. These substances were not designed to be anything, they were discovered, and discovered to have an array of effects. They interact with a wide range of receptors, signalling pathways, and have a range of metabolic consequences.</p>\n<p>From the &quot;Chemistry&quot; chapter:</p>\n<blockquote>\n<p>This arachidonic acid cascade is of great importance in inflammation, pain, and fever. Prostanoid synthesis is significantly elevated in inflamed tissues, where PGE2 and prostacyclin (PGI2) contribute to this response by increasing local blood flow, vascular permeability, and leukocyte infiltration. These prostanoids also cause peripheral sensitization by reducing the threshold of peripheral nociceptors, while PGE2 and other prostaglandins induce central nociceptive sensitization at the spinal dorsal horn neurons. Finally, PGE2 acts at the hypothalamus to increase body temperature by increasing heat production and reducing heat loss. Likewise, inhibition of prostanoid synthesis by NSAIDs is responsible for undesired side effects such as gastrointestinal and renal toxicities, since prostanoids are physiological regulators of gastrointestinal mucosal defense and renal homeostasis.</p>\n</blockquote>\n<p>Conceptually, reducing inflammation only reduces pain if the inflammation caused the pain. If there is pain that is reduced by anti-inflammatory drugs without inflammation present, then the anti-inflammatory effect observed to be <em>a</em> feature of these drugs will have little explanatory value.</p>\n<p>In this case, these drugs can do both, separately or at the same time. There is no &quot;by-product&quot;, but a range of effects to expect. If we need just one effect, good, if we need both effects at once, even better.</p>\n", "score": 2 }, { "answer_id": 18109, "body": "<p>Simply, Nonsteroidal anti-inflammatory drugs (NSAIDs) produce their therapeutic activities (Pain and Inflammation relief) through inhibition of cyclooxygenase (COX), the enzyme that makes prostaglandins (PGs).</p>\n", "score": 1 } ]
18,038
CC BY-SA 4.0
Do NSAIDs &quot;Relieve Pain&quot; or is it a Byproduct?
[ "nsaids-pain-meds" ]
<blockquote> <p>NSAIDs work by inhibiting the activity of cyclooxygenase enzymes (COX-1 and/or COX-2). In cells, these enzymes are involved in the synthesis of key biological mediators, namely prostaglandins which are involved in inflammation, and thromboxanes which are involved in blood clotting.</p> </blockquote> <p><a href="https://en.wikipedia.org/wiki/Nonsteroidal_anti-inflammatory_drug" rel="noreferrer">https://en.wikipedia.org/wiki/Nonsteroidal_anti-inflammatory_drug</a></p> <p>I am trying to understand what ibuprofen / aspirin / etc actually do. I know nothing about biology, so I don't really know what "pain" really is. With that said, do NSAIDs just reduce inflammation, thereby reducing pain as a "side-effect". Or do they reduce inflammation and have another, primary, effect of reducing pain somehow?</p> <p>In short, let's say I burn my arm. Will ibuprofen reduce pain, or does it only reduce pain when an injury is aggrevated by inflammation, e.g. inflammed cartilage rubbing together?</p>
7
https://medicalsciences.stackexchange.com/questions/18121/what-is-asperger-s-syndrome-in-relation-to-autism
[ { "answer_id": 18126, "body": "<p>Mental health conditions are diagnosed through criteria set out in the Diagnostic and Statistical Manual of Mental Disorders (DSM) produced by the American Psychiatric Association (APA). The current version is <a href=\"https://www.psychiatry.org/psychiatrists/practice/dsm\" rel=\"noreferrer\">DSM-5</a> and the previous version was the DSM-IV.</p>\n\n<p>As you pointed out in the comments, Asperger's Disorder is a variant of Autism with a separate set of diagnostic criteria. Because of this, Autism and Asperger's Disorder was a separate diagnosis under DSM-IV even though Asperger's Disorder is on the lower end of the autistic spectrum.</p>\n\n<p>DSM-5 redefined the autism spectrum disorders expanding the <strong>umbrella term</strong> to encompass the previous diagnoses of autism, Asperger syndrome, pervasive developmental disorder not otherwise specified (PDD-NOS), and childhood disintegrative disorder (<a href=\"https://web.archive.org/web/20131006210933/http://www.dsm5.org/Documents/Autism%20Spectrum%20Disorder%20Fact%20Sheet.pdf\" rel=\"noreferrer\">APA, 2013</a>)</p>\n\n<blockquote>\n <p>Using DSM-IV, patients could be diagnosed with four separate disorders: autistic disorder, Asperger’s disorder, childhood disintegrative disorder, or the catch-all diagnosis of pervasive developmental disorder not otherwise specified. Researchers found that these separate diagnoses were not consistently applied across different clinics and treatment centers. Anyone diagnosed with one of the four pervasive developmental disorders (PDD) from DSM-IV should still meet the criteria for ASD in DSM-5 or another, more accurate DSM-5 diagnosis. While DSM does not outline recommended treatment and services for mental disorders, determining an accurate diagnosis is a first step for a clinician in defining a treatment plan for a patient.</p>\n \n <p>The Neurodevelopmental Work Group, led by Susan Swedo, MD (<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/22449639\" rel=\"noreferrer\">Swedo, et al. 2012</a>), senior investigator at the National Institute of Mental Health, recommended the DSM-5 criteria for ASD to be a better reflection of the state of knowledge about autism. The Work Group believes a single umbrella disorder will improve the diagnosis of ASD without limiting the sensitivity of the criteria, or substantially changing the number of children being diagnosed. </p>\n</blockquote>\n\n<h2>References</h2>\n\n<p>APA (2013) <em>Autism Spectrum Disorder Fact Sheet</em>. [PDF Online]<br>Retrieved from: <a href=\"https://web.archive.org/web/20131006210933/http://www.dsm5.org/Documents/Autism%20Spectrum%20Disorder%20Fact%20Sheet.pdf\" rel=\"noreferrer\">https://web.archive.org/web/20131006210933/http://www.dsm5.org/Documents/Autism%20Spectrum%20Disorder%20Fact%20Sheet.pdf</a></p>\n\n<p>Swedo, S. E., Baird, G., Cook, E. H., Happé, F. G., Harris, J. C., Kaufmann, W. E., ... &amp; Spence, S. J. (2012). Commentary from the DSM-5 workgroup on neurodevelopmental disorders. <em>Journal of the American Academy of Child &amp; Adolescent Psychiatry, 51</em>(4), 347-349. doi: <a href=\"https://doi.org/10.1016/j.jaac.2012.02.013\" rel=\"noreferrer\">10.1016/j.jaac.2012.02.013</a> PubMed: <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/22449639\" rel=\"noreferrer\">22449639</a></p>\n", "score": 9 }, { "answer_id": 18245, "body": "<p><strong>Asperger’s syndrome</strong> is a condition that doctors refer to as high-functioning ASD autism spectrum disorder which impacts on the individual’s ability to read and communicate socially.</p>\n\n<p>The symptoms of this condition are less severe and no such signs for language delays are observed.</p>\n\n<p>I work as a sped teacher at ACCEL, and one of the major differences between children with Asperger’s syndrome and autism is that the symptoms are mildly affected and have good language.</p>\n\n<p>Another distinction between Asperger’s syndrome and autism concerns cognitive ability.\nEarly diagnosis and treatment are important for individuals with Asperger’s syndrome to eventually live independently.</p>\n\n<p>Individuals are quite reluctant towards social communication with others and show interest in specific topics.</p>\n\n<p>Communication training and behavioral therapy can help people with the syndrome learn to socialize more successfully.</p>\n\n<p><em>References:</em></p>\n\n<p><em><a href=\"https://www.autismspeaks.org/what-asperger-syndrome\" rel=\"nofollow noreferrer\">https://www.autismspeaks.org/what-asperger-syndrome</a></em></p>\n\n<p><em><a href=\"http://www.autism-society.org/what-is/aspergers-syndrome/\" rel=\"nofollow noreferrer\">http://www.autism-society.org/what-is/aspergers-syndrome/</a></em></p>\n\n<p><em><a href=\"https://www.everydayhealth.com/aspergers/how-aspergers-different-than-autism/\" rel=\"nofollow noreferrer\">https://www.everydayhealth.com/aspergers/how-aspergers-different-than-autism/</a></em></p>\n", "score": 2 }, { "answer_id": 25461, "body": "<p>Hans Asperger, who first reported this kind of condition, used the term &quot;autistic psychopathy&quot; (<a href=\"https://doi.org/10.1017/CBO9780511526770.002\" rel=\"nofollow noreferrer\">DOI</a>). From very beginning of discovery of this condition, people were aware that Aspergers is sort of autism.</p>\n<p>Reference:</p>\n<ol>\n<li><p>Asperger, H. (n.d.). “Autistic psychopathy” in childhood. Autism and Asperger Syndrome, 37–92. doi:10.1017/cbo9780511526770.002 Translated by Uta Frith</p>\n</li>\n<li><p>Wolff, S. (1996). The first account of the syndrome Asperger described? European Child &amp; Adolescent Psychiatry, 5(3), 119–132. doi:10.1007/bf00571671 Translation of a paper entitled &quot;Die schizoiden Psychopathien im Kindesalter&quot; by Dr. G.E. Ssucharewa; scientific assistant, which appeared in 1926 in the Monatsschrift fur Psychiatrie und Neurologie 60:235-261</p>\n</li>\n</ol>\n", "score": 1 } ]
18,121
CC BY-SA 4.0
What is Asperger‘s syndrome in relation to autism?
[ "autism", "aspergers-syndrome" ]
<p>How closely is Asperger‘s syndrome related to autism? I’m curious as I’ve got both.</p>
7
https://medicalsciences.stackexchange.com/questions/18470/the-ethics-of-extra-treatment
[ { "answer_id": 18471, "body": "<p>You're describing an unexpected intra-operative finding. The possibility of unexpected findings (and their treatment) is usually discussed during the consent for the original procedure. Of course, in this situation, there was no initial discussion. The way this sort of issue is usually framed in medical ethics uses a framework of four principles (see Beauchamp and Childress, Principles of Biomedical Ethics): autonomy, beneficence, non-maleficence, and justice. Here, beneficence (the best interest of the patient), outweighs autonomy (the right of the patient to make his or her own choice) for the life saving surgery, and the same would need to occur for addressing the unexpected finding. One would have to (intraoperatively) consider the risks and benefits of removing the tumor, as well as the risks of a second operation were the surgeon to defer. In, e.g., a laparotomy, a readily visualized tumor would almost certainly be removed and sent to pathology. Other cases (e.g., neurosurgery, with a tumor involving eloquent cortex), are more complicated. This sort of thing is less common now, given the likelihood of seeing any tumor that would be obvious during surgery ahead of time with high resolution cross sectional imaging, but it does happen. </p>\n\n<p>You can read a little about the decision making around unexpected intra-operative findings <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23177065\" rel=\"noreferrer\">here</a>, in the context of abdominal surgery.</p>\n", "score": 7 } ]
18,470
CC BY-SA 4.0
The Ethics of extra treatment
[ "cancer", "surgery", "medical-ethics" ]
<p>This is something that I have been considering for quite a while based on a fictional story I had read.</p> <p>An unconscious individual must undergo emergency surgery in order to stabilise them and prevent the patent's death. This medical intervention is happening without the patent's explicit consent however since a reasonable person can be expected to consent to life saving surgery (absent a living will or some other indication) I don't think anyone would have any ethical concerns about it.</p> <p>However while the surgery is occurring something that would not cause immediate harm but is highly likely to cause extreme disability in the long term is discovered (for example a tumour). Is it ethical to fix this newly discovered condition at the same time?</p>
7
https://medicalsciences.stackexchange.com/questions/18473/what-is-the-difference-between-eisenmenger-syndrome-and-ventricular-septal-defec
[ { "answer_id": 18479, "body": "<h1>Ventricular septal defect</h1>\n\n<p>A <a href=\"https://emedicine.medscape.com/article/892980-overview\" rel=\"noreferrer\">ventricular septal defect</a> (VSD) is a <a href=\"https://www.merriam-webster.com/dictionary/congenital\" rel=\"noreferrer\">congenital</a> defect of the central wall (septum) of the heart. This septum divides the right ventricle of the heart from the left ventricle.</p>\n\n<p>The right side of the heart receives blood from the head and body (via the vena cava) and pumps it to the lungs to be oxygenated.</p>\n\n<p>The left side of the heart receives oxygenated blood from the lungs and returns it to the body (via the aorta). The left side is at a higher pressure than the right.</p>\n\n<p><strong>Heart anatomy and ventricular septal defect</strong></p>\n\n<p><a href=\"https://i.stack.imgur.com/qUIW7.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/qUIW7.jpg\" alt=\"Heart and VSD\"></a></p>\n\n<p>Note that the right side of the heart is on the left side of the image and vice versa.</p>\n\n<p>A VSD results in oxygenated blood being pushed (or <em>shunted</em>) from the higher pressure left ventricle through the defect to the right ventricle, where it will travel to the lungs again (unnecessarily).</p>\n\n<hr>\n\n<h1>Eisenmenger’s syndrome</h1>\n\n<p><a href=\"https://emedicine.medscape.com/article/154555-overview\" rel=\"noreferrer\">Eisenmenger’s syndrome</a> is a complication that can arise from many untreated heart defects (including VSD).</p>\n\n<p><strong>Pathophysiology of Eisenmenger’s syndrome</strong></p>\n\n<p><a href=\"https://i.stack.imgur.com/oRjxD.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/oRjxD.jpg\" alt=\"Pathophysiology of Eisenmenger’s syndrome\"></a></p>\n\n<p>The left-to-right shunt causes increased blood flow to the lungs, which damages the endothelium (inner lining) of the blood vessels. This results in gradually increasing vascular resistance in the lungs. </p>\n\n<p>Eventually the resistance gets to a point where the pressure in the right ventricle rises above that of the left ventricle across the VSD. As a result, the shunting reverses, so that blood is now moving from right to left.</p>\n\n<p><a href=\"https://i.stack.imgur.com/JioXT.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/JioXT.jpg\" alt=\"Eisenmenger’s syndrome\"></a></p>\n\n<p>This is a problem because blood is now bypassing the lungs, resulting in reduced oxygen availability to the body (<a href=\"https://en.m.wikipedia.org/wiki/Hypoxia_(medical)\" rel=\"noreferrer\">hypoxia</a>).</p>\n\n<p>This can result in cyanosis (blue discolouration due to hypoxia), heart failure, breathlessness, chest pain, fatigue, haemoptysis (coughing blood), collapse and cardiac arrest.</p>\n\n<hr>\n\n<h1>Summary</h1>\n\n<p>In summary, a VSD is a congenital defect of the heart, and Eisenmenger’s syndrome is a potential long-term complication that can arise if it is left untreated.</p>\n\n<hr>\n\n<p>You can read more about the two conditions by following the links.</p>\n\n<p>Images courtesy of the American Medical Association and Mayo Clinic.</p>\n", "score": 8 }, { "answer_id": 18480, "body": "<p>Eisenmenger syndrome is a clinical syndrome. A ventricular septal defect (VSD) is an anatomic lesion. They are related in that Eisenmenger syndrome can be caused by a VSD (among other things).</p>\n<h3>VSD</h3>\n<p>A <a href=\"https://en.wikipedia.org/wiki/Ventricular_septal_defect\" rel=\"noreferrer\">ventricular septal defect</a> is a (typically) congenital opening between the right and left ventricle, caused by a failure of the ventricular septum, or wall between the two ventricles, to fully develop</p>\n<h3>Eisenmenger syndrome</h3>\n<p>Eisenmenger syndrome is a clinical syndrome and disease process in which a (congenital) <a href=\"https://en.wikipedia.org/wiki/Cardiac_shunt\" rel=\"noreferrer\">left to right shunt</a> (from the systemic circulation to the pulmonary circulation) causes the development of pulmonary vascular disease, <a href=\"https://en.wikipedia.org/wiki/Pulmonary_hypertension\" rel=\"noreferrer\">pulmonary hypertension</a>, and eventually a <a href=\"https://en.wikipedia.org/wiki/Cardiac_shunt\" rel=\"noreferrer\">right to left shunt</a>, leading to <a href=\"https://en.wikipedia.org/wiki/Cyanosis\" rel=\"noreferrer\">cyanosis</a> (a bluish discoloration of the skin caused by inadequate oxygenation of blood). The eventual right to left shunt means that blood returning from the systemic veins goes directly through to the systemic arteries without passing through the pulmonary circulation and the lungs. This prevents gas exchange. Ventricular septal defects are the most common cause of Eisenmenger syndrome, but other initial left to right shunts can cause the same syndrome. <a href=\"https://en.wikipedia.org/wiki/Atrial_septal_defect\" rel=\"noreferrer\">Atrial septal defects</a> and a <a href=\"https://en.wikipedia.org/wiki/Patent_ductus_arteriosus\" rel=\"noreferrer\">patent ductus arteriosus</a> are also relatively common causes of Eisenmenger syndrome.</p>\n<p>I've added links to competent Wikipedia articles about some of the terms here, and you can read about Eisenmenger Syndrome, VSDs, and other congenital cardiac shunts in Lilly's Pathophysiology of Heart Disease, Chapter 16, on Congenital Heart Disease.</p>\n", "score": 7 }, { "answer_id": 18496, "body": "<p>Apart from information on differences given in two excellent answers here, there is a major difference in treatment of these two conditions. </p>\n\n<p>Ventricular Septal Defect (VSD) before development of Eisenmenger syndrome can be treated by surgery. Usually the defect is closed using a patch. Closure can sometimes be done without surgery using devices inserted through peripheral arteries or veins. </p>\n\n<p>If the VSD is very small, it may not need any treatment at all apart from preventive measures to be taken at time of other medical and dental procedures. These are required since there may be a risk of infection at the site of VSD from bacteria that may enter the bloodstream during these procedures.</p>\n\n<p>However, once Eisenmenger syndrome (irreversible pulmonary hypertension with reversal of shunt) develops, surgery (or device closure) is no more an option and condition is generally managed by medicines only. </p>\n\n<p>Pregnancy also carries an increased risk in patients with Eisenmenger syndrome while risk is generally not increased in patients who have had VSD successfully closed earlier.</p>\n\n<p>See this American Heart Association (AHA) page: <a href=\"https://www.heart.org/en/health-topics/congenital-heart-defects/about-congenital-heart-defects/ventricular-septal-defect-vsd\" rel=\"nofollow noreferrer\">https://www.heart.org/en/health-topics/congenital-heart-defects/about-congenital-heart-defects/ventricular-septal-defect-vsd</a> for more information (search for 'pulmonary hypertension', since the term 'Eisenmenger syndrome' is not used there).</p>\n\n<p>Treatment/management options are best discussed with treating doctors since many factors have to be taken into account before deciding best course of action.</p>\n", "score": 4 } ]
18,473
CC BY-SA 4.0
What is the difference between Eisenmenger syndrome and ventricular septal defect?
[ "cardiology", "heart-disease" ]
<p>What is the difference between Eisenmenger syndrome and ventricular septal defect? </p> <p>They are both related to a hole between the two ventricles, right?</p>
7
https://medicalsciences.stackexchange.com/questions/18490/how-are-surgical-patients-kept-still-while-awake
[ { "answer_id": 18821, "body": "<p>I am an anesthetic nurse and have been present at different neurosurgical operations while patients were awake. Mainly brain tumors, but also some stimulation electrodes to fight tremor in Parkinson disease.</p>\n\n<p>There are different techniques used to make sure the patient is well prepared and can deal with the situation - which is in my opinion already the most important part.</p>\n\n<p>a)Patient will be extensively talking with the exact anesthetist that is present during the surgery and the surgeon that is working on them and go through the parts they are awake to be prepared</p>\n\n<p>b) it will be discussed with the patient if they want to be awake throughout the surgery or want to wake up for the part they are needed - opening the skull with a surgical saw is not really pleasing, so that needs to be clarified. Also there will be options to put you to sleep any time, since panic is not a good option while your head is tightly screwed to a table - the patient knows about what and how to communicate at any time during surgery. Also for seizures medication would be started beforehand to lower the threshold for a seizure. A tremor generally isn't a problem as they normally are not strong enough to do harm to a body that is fixated.</p>\n\n<p>c) during surgery a constant contact will be established between surgeon, anesthetist and patient, it has been proven useful to use autosuggestion techniques and tasks patients like to keep them occupied or cope with the situation. Due to this also seizures will be identified early and can immediately be treated, this might include a short general anesthesia.</p>\n\n<p>d) During surgery you can make some stops if patient is feeling uncomfortable, for example sitting up. We had surgeons who stepped away and went to eat and drink for 15 minutes while the patient had some time to recover. Anxiety to a certain degree can be medically softened, but since an awake patient is needed you are careful with it. Short acting agents like Propofol (Sedation) or Remifentanyl (Painkiller and sedation) are often connected via syringe pump, a baseline can be established with a benzodiazepine like midazolam (Which also can be antagonized if necessary). Also the concentrated talking with a good anesthetist and using meditative/autosuggestion techniques calms down most patients remarkably good.\nObviously you would also check that local anesthesia is still working and the position is comfortable for the patient.</p>\n\n<p>e) If these things do not help for brain tumors you could try to go for navigation (which is common these days, it is a 3d model of the patient matched with the CT of the brains so you can identify the tumor[1]), stimulation or hope the surgeon has enough experience to exactly stop before entering healthy tissue. Also you would ask pathology to confirm you are not yet in healthy tissue by sending them a sample (This takes about half an hour in which you will just wait) - also the surgeon might decide to stop and to leave the rest inside, which is a complicated decision based on which outcome the incision in healthy tissue might have, if there are real chances to cure the patient even if surgery is perfectly done and so forth.\nFor stimulation electrodes a panicking patient is a no go, so if you do not manage to get them relaxed you will stop the surgery and not place the electrode. I have not seen it because this is really rare due to the preparation and experienced people all around you.</p>\n\n<p>I am sorry for not providing more sources, but to find something as specific as that summed up in a good way is rather complicated. I have to the best of my knowledge described my experience from three different hospitals in Germany where I have witnessed the practice and information from a specialist who gave a talk on autosuggestion in awake surgery.</p>\n\n<p>[1] <a href=\"https://www.youtube.com/watch?v=jYCiKOERYD8\" rel=\"nofollow noreferrer\">https://www.youtube.com/watch?v=jYCiKOERYD8</a></p>\n", "score": 3 } ]
18,490
CC BY-SA 4.0
How are surgical patients kept still while awake?
[ "treatment", "surgery", "muscle", "muscle-tremor-twitch" ]
<p><a href="https://www.mayoclinic.org/tests-procedures/awake-brain-surgery/about/pac-20384913" rel="nofollow noreferrer">Certain surgeries</a> require the patient to be awake and lucid to be performed safely. If the patient has clonus, epileptic seizures, tremors, or any of a number of other symptoms, staying still during the part of the surgery in which the patient is awake can be difficult. Clearly, this is dangerous.</p> <p>When a surgical patient who for reasons medical or otherwise cannot keep still is required to be awake during part of a surgery, how is this risk of unintentional harm dealt with?</p>
7
https://medicalsciences.stackexchange.com/questions/18561/what-are-the-official-eye-colors
[ { "answer_id": 19389, "body": "<p>There is no strong scientific consensus on eye colors.\nBut for example, per 2019 review article at <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/30639910\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pubmed/30639910</a> the colors listed in that review are blue, brown and intermediate</p>\n\n<p>So one approach is to bundle the non brown and non blue into a single category called 'intermediate'.</p>\n\n<p>The top of a long table is pasted here to demonstrate that.</p>\n\n<p><a href=\"https://i.stack.imgur.com/IVC2A.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/IVC2A.png\" alt=\"enter image description here\"></a></p>\n", "score": 1 } ]
18,561
CC BY-SA 4.0
What are the official eye colors?
[ "eye" ]
<p>In reading <a href="https://en.wikipedia.org/wiki/Eye_color" rel="nofollow noreferrer">the wikipedia article on eye color</a>, I noticed that the colors listed there seemed a bit arbitrary. Tangentially, I know that even the words we use today to recognize colors are neither old nor preserved through cultures, languages, or time. As an example, Spanish speaking peoples often use the word black to describe eye color, but English speaking peoples would say dark brown. </p> <p>This left me wondering if the worldwide medical community (represented by the world health organisation or something else) has a distinct nomenclature for human eye colors. If they do, what are the various "official" eye colors? </p>
7
https://medicalsciences.stackexchange.com/questions/18577/lactulose-and-dental-decay
[ { "answer_id": 18761, "body": "<p>This saccharide is of very minute risk, absolutely, and even more so if compared with glucose, fructose or saccharose.</p>\n\n<p>Two reasons: </p>\n\n<ol>\n<li>Caries is the result of microbiota producing acids which dissolve the enamel, and</li>\n<li>this effect is enhanced when this takes place under plaque when and where saliva cannot dilute the acids</li>\n</ol>\n\n<p>For reason 1:</p>\n\n<blockquote>\n <p>Most bacteria tested were able to metabolize lactulose with the exception of strains of Streptococcus salivarius, Lactobacillus acidophilus and Lact. fermentum. Streptococcus mutans produced most acid overnight but the initial rate of acid production from lactulose by uninduced cultures was very low. Plaque pH was monitored in 12 volunteers following rinsing the mouth with lactulose, sucrose or sorbitol or Lactulose BP.\n These studies in vivo showed both lactulose and Lactulose BP to exhibit low acidogenic potential. Thus, although plaque bacteria are capable of fermenting lactulose, the results suggest that lactulose is likely to pose a small acidogenic challenge to teeth under normal conditions of use.<br>\n <sub><a href=\"https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1472-765X.1998.00403.x\" rel=\"nofollow noreferrer\">P.J. Moynihan, S. Ferrier, S. Blomley, W.G. Wright and R.R.B. Russell: \"Acid production from lactulose by dental plaque bacteria\", Letters in Applied Microbiology 1998, 27, 173–177.</a> <a href=\"https://doi.org/10.1046/j.1472-765X.1998.00403.x\" rel=\"nofollow noreferrer\">DOI</a></sub></p>\n</blockquote>\n\n<p>This has to be read in perspective, as S. mutans is <em>capable</em> of using lactulose, but not very efficient in doing so and while overnight the acid production is <em>comparatively</em> higher, it is quite low overall, compared to saccharose.</p>\n\n<p>For reason 2:</p>\n\n<p>Different sugars present the bacteria with different challenges in metabolising them. Dental plaque is mainly hold together by dextranes (extracellullar polysaccharides), which are not easily synthesised and excreted by the microbes, if they are fed lactulose.</p>\n\n<blockquote>\n<pre><code>Carbohydrate pH extracellullar polysaccharides\n--- (mcg/ml n = 2) \nGlucose 4.55 110\nFructose 4.8 --\nInvertzucker 4.2 --\nSaccharose 4.7 1950\nRaffinose 4.7 500\nStachyose 4.7 350\nLeucrose 4.6 2600\nPalatinose 5.1 2070\nLactulose 4.7 --\n</code></pre>\n \n <p><sub>Formation of extracellular polysaccharides in the presence of selected saccharides by Streptococcus mutans Ingbritt (incubation time 48h / 37°C)</sub></p>\n \n <p>Summary: In the light of recent literature, the authors outline the state of our knowledge of the bio-chemico-microbiological actiology of dental caries. From experimental studies it is evident that the ,,cariogenic\" streptococcal strain S. mutans Ingbritt synthetizes in vitro extracellular dextrans suited for plaque formation not only preferentially from saccharose but also from a series of glucose-containing fructosides. No such synthesis was observed with the non-cariogenic S. faecalis. Systematic experiments are indicative of the trend that in the cariogenic S. mutans Ingbritt the activity of the synthetizing dextran sucrase is greater by about one power of ten than in S. faecalis. It seems that the dextran sucrase activity is a contributory determinant of the character of cariogenic streptococci.</p>\n \n <p><sub><a href=\"https://onlinelibrary.wiley.com/doi/abs/10.1002/food.19700140503\" rel=\"nofollow noreferrer\">A Täufel &amp; K Täufel: \"Zum mikrobiellen Verhalten von Gluco-Fructosiden gegenüber den Streptokokken der Mundflora\n im Hinblick auf die Zahnkaries\", Die Nahrung, 14, 5 1970, p331-337.</a> <a href=\"https://doi.org/10.1002/food.19700140503\" rel=\"nofollow noreferrer\">DOI</a></sub></p>\n</blockquote>\n\n<p>Meaning that metabolic activity of cariogenic bacteria is relatively low and their ability to form a biofilm plaque is much reduced if we look at isolated load from lactulose. Since bacteria can adapt and the flora of a mouth change, it's probably still not a good idea to really bath the teeth in lactulose solutions, but given the application as gastrointestinal treatment that's just swallowed quite quickly, the concern seems really low.</p>\n", "score": 4 } ]
18,577
CC BY-SA 4.0
Lactulose and dental decay
[ "dentistry", "gastroenterology", "tooth-decay", "constipation", "laxative" ]
<p><a href="https://en.m.wikipedia.org/wiki/Lactulose" rel="nofollow noreferrer">Lactulose</a> is an <a href="https://www.nhs.uk/conditions/laxatives/" rel="nofollow noreferrer">osmotic laxative</a> made from the milk sugar <a href="https://en.m.wikipedia.org/wiki/Lactose" rel="nofollow noreferrer">lactose</a>. It is non-absorbable in the gut, and so draws water into the gut by osmosis, with the aim of alleviating constipation.</p> <p>I have heard a dentist advise that it should be used with caution in children as it can contribute to dental decay. The Wikipedia article (linked above) just states (without a reference) that it is less likely to cause tooth decay than sucrose.</p> <p>Do we know whether dental decay is actually likely with regular use of lactulose, or what the risk is compared to sucrose?</p>
7
https://medicalsciences.stackexchange.com/questions/18663/does-an-organ-of-a-male-donor-work-on-a-female-patient
[ { "answer_id": 18664, "body": "<p>The Chromosomes are not the main Factor in this. The immune system (and antibodies) is, this is a bit different. For example females have a higher HLA antigens and therefore rely on more immunsuppressive therapy.</p>\n<p>This Therapy is the thing that makes a transplantation possible, nearly all Organs are incompatible to the body, that means that you always have to give medication to stop the body from attacking the new organ. How much is needed is done via HLA matching (see <a href=\"https://health.ucdavis.edu/transplant/learnabout/learn_hla_type_match.html\" rel=\"noreferrer\">UC Davis (n.d.)</a>), which is quite extensive as a topic, you can read the lkink if you want to dig deeper.\nIn short, depending on the HLA classification you might have a risk to not accept your new organ and therefore your medication will be tailored to the compatibility.</p>\n<p>Also difference between Male/Female in general is comparably small,there are some studies and you can read <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4964018/\" rel=\"noreferrer\">Puoti et al (2016)</a> for some differences in survival rates etc.</p>\n<h2>References</h2>\n<p>Puoti, F., Ricci, A., Nanni-Costa, A., Ricciardi, W., Malorni, W., &amp; Ortona, E. (2016). Organ transplantation and gender differences: a paradigmatic example of intertwining between biological and sociocultural determinants. <em>Biology of sex differences, 7</em>(1), 35. doi: <a href=\"https://doi.org/10.1186/s13293-016-0088-4\" rel=\"noreferrer\">10.1186/s13293-016-0088-4</a> pmcid: <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4964018/\" rel=\"noreferrer\">4964018</a></p>\n<p>UC Davis (n.d.) <em>HLA Typing/Matching</em> [Online]<br>\nRetrieved from: <a href=\"https://health.ucdavis.edu/transplant/learnabout/learn_hla_type_match.html\" rel=\"noreferrer\">https://health.ucdavis.edu/transplant/learnabout/learn_hla_type_match.html</a></p>\n", "score": 13 }, { "answer_id": 18689, "body": "<p>@NilsPawlik has addressed the issue of a donor/recipient gender mismatch (it's not the most important factor, but it is something to consider). I thought I'd clarify the point about donor/recipient compatibility. </p>\n\n<h2>What makes an organ compatible?</h2>\n\n<p>There are a number different things that make a donor organ work more or less well for a recipient, but each kind of organ has its own challenges. For example, where size matching is not an issue for liver transplants, it is important for heart transplants, and may be a little important for kidney transplants (Schwartz Principles of Surgery, Ch. 11)*. For all solid organ transplants, though, the <em>major</em> driver of organ and tissue compatibility is found in 6 genes on the short arm of chromosome 6.</p>\n\n<h2>Antigens distinguish self from non-self</h2>\n\n<p>All jawed vertebrates have an adaptive immune system and are able to tell the difference between invaders (non-self) and things that are a part of their own body (self). This system works by examining patterns in biological molecules (proteins, sugars, lipids). Those patterns are called antigens. When you transplant an organ from a donor to a recipient, the recipient's immune system will look at the antigens, or patterns, on the cells of the donor organ, and make a decision about whether those cells are part of their body or part of an invader.</p>\n\n<h2>Identifying and responding to antigens involves the entire immune system</h2>\n\n<p>The way the immune system examines and responds to those antigens involves a whole series of important and complicated interactions between many different soluble proteins, receptors, and cells, including antibodies, T-cell receptors, cytokines, macrophages, and more, but the key to predicting which organs will work well is looking at the antigens themselves. </p>\n\n<h2>HLAs determine whether a recipient will recognize a donor organ as self or non-self</h2>\n\n<p>The most important antigens for figuring out whether a human donor organ will be compatible with a human recipient are called Human Leukocyte Antigens (HLA), because they are molecular patterns (antigens) initially discovered on human white blood cells (leukocytes). These antigens are very important functional proteins that play a particular role in the way the immune system works, but for our purposes you can just think of them as being little markers on each cell saying either <em>\"I'm one of you!\"</em>, or <em>\"I'm not one of you!\"</em>. </p>\n\n<p>These markers (human leukocyte antigens) are encoded in the genome. Their genes are found on the short arm of chromosome 6. These genes are part of a group of genes called the Major Histocompatibility Complex (or MHC), because they are a <strong>major</strong> part of determining whether a donor <strong>tissue (histo)</strong> will be <strong>compatible</strong> with a recipient's immune system. </p>\n\n<h2>What kind of a match do you need?</h2>\n\n<p>There are many many many different types of MHC alleles. Because HLAs strongly influence our ability to respond to infection, this variability is a good thing overall, but it makes transplant immunology complicated. Because there are so many different MHC alleles, finding a match can be difficult. Organs are in short supply, though, so rather than waiting for an exact match, the goal is often to <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5141243/\" rel=\"noreferrer\">find a match that is good enough</a>.</p>\n\n<h2>Further Reading</h2>\n\n<p>In addition to the linked articles and the surgical considerations discussed in Schwartz, much of the relevant immunology here is discussed in good detail in the Transplant Immunology subsection of Chapter 11. I also recommend Lauren Sompayrac's little book, How the Immune System Works for either an introduction or review.</p>\n\n<h2>Note</h2>\n\n<p>*Even the mechanisms of immune rejection vary from organ type to organ type. Liver transplants, for example, are not as susceptible to the kind of rejection that is caused by pre-formed antibodies. They are more susceptible to the kind caused by T-cells (again, Schwartz Ch. 11, unless <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4607901/\" rel=\"noreferrer\">you want to see how this is even more complicated</a>)</p>\n", "score": 6 } ]
18,663
CC BY-SA 4.0
Does an organ of a male donor work on a female patient?
[ "kidney", "organ-donation" ]
<p>Each cell of a human body contains 46 chromosomes. If so then each cell of a kidney should have a pair of sex chromosomes. <strong>How is it possible that a kidney of a female donor will work on male kidney patient?</strong></p>
7
https://medicalsciences.stackexchange.com/questions/18916/is-it-safe-to-use-olive-oil-to-clean-the-ear-wax
[ { "answer_id": 18919, "body": "<p>Based on this systematic review, <a href=\"https://www.journalslibrary.nihr.ac.uk/hta/hta14280/#/abstract\" rel=\"noreferrer\">The safety and effectiveness of different methods of ear wax removal: a systematic review and economic evaluation</a>:</p>\n\n<blockquote>\n <p>On measures of wax clearance Cerumol, sodium bicarbonate, <strong>olive oil</strong> and water are all more effective than no treatment; <strong>triethanolamine polypeptide (TP) is better than olive oil</strong>; wet irrigation is better than dry irrigation; sodium bicarbonate drops followed by irrigation by nurse is more effective than sodium bicarbonate drops followed by self-irrigation ....</p>\n</blockquote>\n\n<p>However, it should be noticed that:</p>\n\n<blockquote>\n <p>limited good-quality evidence of the safety, benefits and costs of the different strategies, making it difficult to differentiate between the various methods for removing earwax and rendering the economic evaluation as speculative <a href=\"https://www.journalslibrary.nihr.ac.uk/hta/hta14280/#/abstract\" rel=\"noreferrer\">reference</a>.</p>\n</blockquote>\n", "score": 11 } ]
18,916
CC BY-SA 4.0
Is it safe to use olive oil to clean the ear wax?
[ "ear", "oil", "earwax" ]
<p>It is safe to use olive oil to clean the ear wax as <a href="https://medicalsciences.stackexchange.com/a/10184/13">advised here</a>?</p> <p><a href="https://www.livestrong.com/article/117542-ear-wax-removal-home-remedy/" rel="noreferrer">This site said it's good</a>:</p> <blockquote> <p>Although there are questions about the effectiveness of any specific ear drops, olive oil -- as long as it's the same or cooler than body temperature -- is not a harmful treatment. Start by placing room temperature olive oil into an ear dropper. Next, put a few drops of olive oil in the affected ear twice daily for 3 to 4 days, and lay on your side for several minutes to allow the oil to penetrate the wax more deeply. After your last planned treatment, and if necessary to get the wax out, use a bulb syringe to gently spray warm water into the ear to encourage the lubricated wax to fall from the ear.</p> </blockquote> <p>But <a href="https://www.netdoctor.co.uk/healthy-living/a28043/olive-oil-in-ears-hearing-ear-wax/" rel="noreferrer">this said it's bad</a>:</p> <blockquote> <p>It's a remedy as old as time, but using olive oil for resolving hearing problems is not a good idea.</p> <p>Here's why: olive oil softens ear wax, of that there is no doubt, but the wax sludge that results still does not go anywhere in the average sized ear canal.</p> </blockquote>
7
https://medicalsciences.stackexchange.com/questions/19107/are-there-websites-with-clinical-trial-reports-freely-available-for-download
[ { "answer_id": 25663, "body": "<p>You could try <a href=\"https://clinicaltrials.gov/\" rel=\"nofollow noreferrer\">ClinicalTrials.gov</a>, where you can search a massive database of clinical trials in every stage of completion.</p>\n", "score": 1 } ]
19,107
CC BY-SA 4.0
Are there websites with clinical trial reports freely available for download?
[ "clinical-study", "reference-request", "regulatory-agencies" ]
<p>I'm a translator, and I'm currently translating clinical trial reports, Russian to English. I wonder if there are depositories of freely available clinical trial reports, with all appendixes and all data. I want to read some reports to make sure that I'm using the correct terminology.</p> <p>I have <a href="https://www.ema.europa.eu/en/ich-e3-structure-content-clinical-study-reports" rel="nofollow noreferrer">ICH guideline documents</a>, of course, but seeing real-life reports, especially the adverse events tables and other table-form data can be helpful.</p>
7
https://medicalsciences.stackexchange.com/questions/19165/emergent-gastric-ischemia
[ { "answer_id": 19186, "body": "<p>Cocaine use is known to cause <em>gastric</em> ischemia or even perforation (in a 19 year old female student with epigastric pain <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3033545/\" rel=\"noreferrer\">PubMed, 2010</a>) and in another 5 relatively young people (<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/2007737/\" rel=\"noreferrer\">PubMed, 1991</a>), or <em>intestinal</em> ischemia (<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1305435/pdf/westjmed00316-0049.pdf\" rel=\"noreferrer\">PubMed, 1999</a>). When there are no symptoms that would differ from those in food poisoning or infectious gastroenteritis, cocaine use alone should raise suspicion for gastric or intestinal ischemia.</p>\n\n<p>Symptoms and signs associated with gastric ischemia can include nausea, vomiting, diarrhea, hypotension (as a cause of ischemia), abdominal pain (angina) and tenderness, chest pain (angina), vomiting blood and blood in stool (<a href=\"https://www.jwatch.org/na33593/2014/02/20/it-gastric-ischemia\" rel=\"noreferrer\">Journal Watch, 2014</a>, <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1360478/\" rel=\"noreferrer\">PubMed, 2006</a>).</p>\n\n<p>It can also help to know the history of underlying conditions in gastric ischemia that can occur in young people: hypotension (e.g. due to arrhythmia or anaphylaxis), vasculitis, pyloric stenosis (which can lead to stomach distension) and paraesophageal hernia (<a href=\"https://link.springer.com/article/10.1007/s10620-017-4807-4\" rel=\"noreferrer\">Springer, 2017</a>).</p>\n\n<p>Diagnosis is by upper endoscopy (<a href=\"https://medcraveonline.com/IJRRT/IJRRT-05-00125\" rel=\"noreferrer\">MedCrave, 2018</a>).</p>\n\n<p>In conclusion, symptoms and signs of gastric ischemia can be very unspecific, but you can <em>suspect</em> it in a person with sustained epigastric pain and known cocaine use.</p>\n", "score": 6 } ]
19,165
CC BY-SA 4.0
Emergent gastric ischemia
[ "emergency", "ischaemia" ]
<p>I saw a <a href="https://www.courant.com/news/connecticut/hc-news-trinity-students-death-cause-20190423-6lemink76baghlbarvbjtfpwya-story.html" rel="noreferrer">news item</a> today that said this:</p> <blockquote> <p>The state medical examiner’s office ruled Tuesday that the death of a Trinity student in November was accidental and caused by a rare stomach disorder that was exacerbated by cocaine use.</p> <p>Chief Medical Examiner James Gill said that Chase Hyde died of gastric ischemia that was complicated by recent cocaine use.</p> </blockquote> <p>Okay, so the cocaine caused vascular constriction that exacerbated his undiagnosed preexisting condition and led to the ischemia. I get that, but that's not my question. </p> <p>He was an apparently healthy young man experiencing protracted nausea and vomiting and he assumed it was due to food poisoning, which isn't an unreasonable assumption. Any physician would likely have assumed the same (or a viral infection) and treated it symptomatically, which would not have saved him.</p> <p>My question is how might he have been successfully diagnosed and treated if he had sought treatment immediately? Is there any scenario in which an astute physician would have identified the actual cause and treated it given the emergent nature and short time frame available? If so, how?</p>
7
https://medicalsciences.stackexchange.com/questions/19609/how-does-psoriasis-change-the-biochemistry-of-blood
[ { "answer_id": 19620, "body": "<blockquote>\n <p>There is no blood test that can definitively diagnose psoriasis\n (<a href=\"https://www.uptodate.com/contents/psoriasis-beyond-the-basics\" rel=\"nofollow noreferrer\">UpToDate</a>).</p>\n</blockquote>\n\n<p>The article linked from the question (<a href=\"https://www.arthritis.org/about-arthritis/types/psoriatic-arthritis/articles/psoriatic-arthritis-increases-gout-risk.php\" rel=\"nofollow noreferrer\">Arthritis.org</a>) mentions several studies; in one of them uric acid was elevated in only <em>20 percent</em> of patients with psoriasis. In another study, it was <em>psoriatic arthritis</em> that was most strongly associated with elevated uric acid. So, it may not be the severity of psoriasis, but rather the type of psoriasis and the presence of arthritis that affects the uric acid levels.</p>\n\n<p>According to this 2015 article <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4610974/\" rel=\"nofollow noreferrer\">Biomarkers of An Autoimmune Skin Disease—Psoriasis</a>, the following <strong>biomarkers</strong> (which are not usually checked in a diagnostic process) can be elevated in psoriasis:</p>\n\n<ul>\n<li>Nonspecific inflammation markers: C-reactive protein (CRP), platelet P-selectin, haptoglobin, complement component 3 (C3), and C4</li>\n<li>Pro-inflammatory cytokines: TNF-α, IFN-γ, IL-6, IL-8, IL-12, and IL-18</li>\n<li>Markers of abnormalities in blood fibrinolysis and coagulation: increased levels of fibrinopeptide A, fibrinogen, D-dimer, and C4, in addition to decreased levels of protein C, alpha 2-antiplasmin, and plasminogen</li>\n</ul>\n", "score": 2 } ]
19,609
CC BY-SA 4.0
How does Psoriasis change the biochemistry of blood?
[ "blood", "psoriasis" ]
<p>I read somewhere that Psoriasis can increase the amount of uric acid in the bloodstream by about 10%, increasing the chance of gout:<a href="https://www.arthritis.org/about-arthritis/types/psoriatic-arthritis/articles/psoriatic-arthritis-increases-gout-risk.php" rel="noreferrer">psoriasis</a> </p> <p>Is this the only biochemical change in the bloodstream of people with psoriasis? Does how severe or mild the psoriasis is have any bearing on the above biochemical changes? </p>
7
https://medicalsciences.stackexchange.com/questions/20060/why-isnt-paracetamol-routinely-combined-with-n-acetylcysteine
[ { "answer_id": 20192, "body": "<p>Several combinations between analgesics and other compounds could be interesting for medical treatment and used in pain treatments, however, the logic isn't only effectiveness. For a medication to be approved by regulatory authorities, such as FDA, as over the counter or under prescription, pharmaceutical companies look first on the ROI (<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537512/\" rel=\"nofollow noreferrer\">return of investment</a>), as any other intervention planned in health care.\nIf the study cost to prove its efficacy is too high, or the market for the new compound not profitable, or the new product could not be patented, then the combination would not go to market. \nParacetamol + N-AcetylCysteine seems to be an interesting combination, but the study to prove it is less harmful would have to include thousands of patients, because the number needed to harm is high, so the <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6267841/\" rel=\"nofollow noreferrer\">sample size calculation</a> would go to very high numbers. Maybe someone from the industry after seeing your post do the calculations and start a project...</p>\n", "score": 3 } ]
20,060
CC BY-SA 4.0
Why isn&#39;t paracetamol routinely combined with n-acetylcysteine?
[ "medications", "side-effects", "prevention", "drug-interactions", "acetaminophen" ]
<p>Whether it's acute large dose paracetamol or long term regular dosage of <a href="https://en.wikipedia.org/wiki/Paracetamol" rel="nofollow noreferrer">paracetamol</a> usage, it is a <a href="https://en.wikipedia.org/wiki/Paracetamol_poisoning" rel="nofollow noreferrer">problem</a> for the liver, <a href="https://doi.org/10.1093/aje/kww154" rel="nofollow noreferrer">ototoxic</a> and even potentially life-threatening.</p> <p>While one might question the use of paracetamol at all, for acute symptoms and occasional use it seems to have a place in being overall well tolerated in short term usage scenarios.</p> <p>But the problematic aspects of the drug leaves me wondering: </p> <p>one mechanism for paracetamol induced damage is reactive oxygene overproduction and <a href="https://en.wikipedia.org/wiki/Glutathione" rel="nofollow noreferrer">glutathione</a> depletion. This is one of the reasons why <a href="https://en.wikipedia.org/wiki/Acetylcysteine" rel="nofollow noreferrer">N-acetylcysteine</a> (NAC) is an <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5987070/" rel="nofollow noreferrer">effective</a> treatment in <a href="https://handbook.ggcmedicines.org.uk/guidelines/drug-overdose-and-toxicity/treatment-of-paracetamol-overdose/" rel="nofollow noreferrer">paracetamol overdose</a> scenarios.</p> <p>So it seems as if combining paracetamol with NAC would be a good idea to prevent the problems from paracetamol use.</p> <p>The fact that it isn't done, neither in formulas nor in prescription routines, is puzzling.</p> <p>NAC seems to be very well <a href="https://www.rxlist.com/consumer_acetylcysteine_mucomyst/drugs-condition.htm" rel="nofollow noreferrer">tolerated</a> if taken orally and even sold as a nutritional <a href="https://www.healthline.com/nutrition/nac-benefits" rel="nofollow noreferrer">supplement</a>. It seems to be quite problematic if injected or taken <a href="https://doi.org/10.1016%2Fj.hepres.2005.12.005" rel="nofollow noreferrer">after alcohol</a> consumption. But alcohol and paracetamol would be a bad idea in itself. </p> <p>Seeing that paracetamol <em>still is</em> combined with for example hydrocodone, a combination that is now clearly shown to be highly problematic for example <a href="https://doi.org/10.1517/17425255.2011.614231" rel="nofollow noreferrer">for hearing</a> is just confusing.</p> <p>In fact, it is an old idea that <em>has been studied</em> to be an effective combination:</p> <p><a href="https://doi.org/10.1136/bmj.322.7296.1203" rel="nofollow noreferrer">Effects of legislation restricting pack sizes of paracetamol and salicylate on self poisoning in the United Kingdom: before and after study</a> (<a href="https://www.bmj.com/rapid-response/2011/10/28/package-paracetamol-its-antidote" rel="nofollow noreferrer">Package paracetamol with its antidote</a>, 2001, 2011)</p> <p><a href="https://www.ncbi.nlm.nih.gov/pubmed/26250417" rel="nofollow noreferrer">Co-administration of N-Acetylcysteine and Acetaminophen Efficiently Blocks Acetaminophen Toxicity</a>. (2015)</p> <p>For the unpopularity of 'paracetamol plus NAC' it seems I must have overlooked something.</p> <p>What are or would be the downsides of combining paracetamol routinely with NAC?</p>
7
https://medicalsciences.stackexchange.com/questions/20065/why-is-down-syndrome-so-common-relative-to-other-chromosomal-conditions
[ { "answer_id": 20696, "body": "<p>I found the answers in a fascinating, and easy to read paper in <em>Nature</em>, called <a href=\"https://www.nature.com/scitable/topicpage/chromosomal-abnormalities-aneuploidies-290/\" rel=\"nofollow noreferrer\">\"Chromosomal Abnormalities: Aneuploidies\"</a> </p>\n\n<p>Here are some key insigths from there:</p>\n\n<blockquote>\n <p>With few exceptions, trisomies do not appear to be compatible with life. In fact, trisomies represent about 35% of spontaneous abortions (Figure 1; Hassold &amp; Hunt, 2001).</p>\n</blockquote>\n\n<p>As far as why trisomy 21 is more survivable than other trisomies of non-sex chromosomes (autosomes), the answer may be in the length of the chromosome -- except for the Y chromosome, #21 has the lowest number of genes, so an excess may be more survivable:</p>\n\n<blockquote>\n <p>In humans, the overexpression of X-linked genes is prevented by X inactivation, but no similar mechanism has been identified for autosomes. It is therefore interesting that trisomy 21 is the only viable autosomal trisomy, because the number of protein-coding sequences predicted for chromosome 21 is the smallest of any human chromosome, with the exception of the Y chromosome. Thus, an additional copy of chromosome 21 would be predicted to perturb the normal equilibrium in cells less than an extra copy of any other autosome.</p>\n</blockquote>\n", "score": 5 } ]
20,065
CC BY-SA 4.0
Why is Down Syndrome so common relative to other chromosomal conditions?
[ "genetics", "chromosomes", "downs-syndrome" ]
<p>According to the <a href="https://www.ndss.org/about-down-syndrome/down-syndrome-facts/" rel="noreferrer">National Down Syndrome Society</a>, Down Syndrome is the most common chromosomal condition, with roughly one in 700 children born in the United States affected. The genetic disease results specifically from a partial or complete extra copy of chromosome 21.</p> <p>What I'd like to know is why this is, when there are 22 other chromosomes that in theory are just as susceptible to nondisjunction (the most common process resulting in the extra copy of chromosome 21, accounting for 95% of cases). Why is chromosome 21 uniquely affected?</p> <p><strong>My personal thoughts, not necessary for understanding the question:</strong></p> <p>It seems to me that there are two likely options here.</p> <p><strong>Option 1</strong> is that there is some property of chromosome 21 that causes it to be treated slightly differently from other chromosomes making such nondisjunction more likely. Perhaps it is the largest, or smallest, or the most guanine-cytosine base pair rich, or poor, and so on, in which case I'd love to hear what it is that differentiates chromosome 21.</p> <p><strong>Option 2</strong> is survivorship bias, namely that chromosome 21 is the only chromosome where trisomy tends not to result in the death of the fetus. If true, this would indicate that trisomy occurs at roughly equal rates in the other chromosomes, but that typically this results in miscarriage.</p>
7
https://medicalsciences.stackexchange.com/questions/20306/is-a-study-of-one-research-in-the-field-of-medicine
[ { "answer_id": 20310, "body": "<p>To build off of what JohnP said, scientific evidence has a hierarchy of reliability. Some types of papers, by their very nature, are more academically rigorous and likely to lead you to the truth.</p>\n\n<p>Randomized controlled double-blind trials and meta-analyses are at the top of the hierarchy. These studies often have thousands of participants and are set up to produce statistically significant results. These studies form the backbone of evidence-based medicine.</p>\n\n<p>A case study, which looks at a finding or condition seen in one patient, is at the bottom of the hierarchy. It's impossible to draw true evidence-based conclusions off of this type of paper, since it essentially says \"here's what we saw, here's what we did, here's what happened\".</p>\n\n<p>However, case studies should not be written off as useless. There are two primary ways that these types of studies can be helpful. </p>\n\n<ul>\n<li>If you are treating a patient with an extremely rare condition or constellation of symptoms, a case study is the best guide you're going to get. If someone else did something which worked in a similar patient, that treatment may work in your patient. Many of those rare diseases will simply never have enough patients to fuel a randomized controlled trial.</li>\n<li>If there is an emerging phenomenon that has not yet been described in the literature. 2 notable examples are HIV/AIDS and the much more recent vaping pneumonitis. Both of these conditions were first identified by case reports (or case series, which is the same thing but with a handful of patients). This brought the issue to wider attention, and once this happened many other similar reports started pouring in. This can direct more academically rigorous research in that direction.</li>\n</ul>\n\n<p>References:</p>\n\n<p><a href=\"https://www.cdc.gov/mmwr/preview/mmwrhtml/june_5.htm\" rel=\"noreferrer\">First case series of patients with complications of AIDS</a></p>\n\n<p><a href=\"https://www.nejm.org/doi/10.1056/NEJMoa1911614\" rel=\"noreferrer\">First case series of vaping pneumonitis</a></p>\n", "score": 8 }, { "answer_id": 20317, "body": "<p>\"Studies of one\" are also known as case studies, N-of-1 studies or case reports. I will refer to them below as <strong>case reports</strong>, for simplicity. They vary in quality just like any other type of studies. Case reports have a place in biomedical research and can often be very valuable, widely cited and/or otherwise influential. Double-blind randomized controlled clinical trials (RCTs), or, better, meta-analysis of multiple such trials, are the current gold standard. But they are obviously not always feasible for a variety of reasons.</p>\n\n<p>There are specific guidelines for writing case reports, for example:</p>\n\n<p>Riley D.S., et al (2017) J Clin Epidemiol. 89:218-235. doi: 10.1016/j.jclinepi.2017.04.026. CARE guidelines for case reports: explanation and elaboration document. <a href=\"https://www.sciencedirect.com/science/article/pii/S0895435617300379\" rel=\"nofollow noreferrer\">https://www.sciencedirect.com/science/article/pii/S0895435617300379</a></p>\n\n<p>This above article also lists a number of peer-reviewed journals that explicitly accept case reports (Table 1), important historical examples of case reports (section 1.1), and different types of case reports with specific examples (section 2).</p>\n\n<p><strong>Types of case reports:</strong></p>\n\n<ul>\n<li><p><strong>Research where the number of patients is limited for any reason.</strong> For example, research conducted the beginning of a potential disease outbreak, research on uniquely informative patients, reports of rare drug side effects, drug-drug and food-drug interactions. Others in this thread have also listed rare condition treatment and emerging phenomena.</p></li>\n<li><p><strong>Research that carries high cost</strong>. For example, whole genome or whole exome sequencing when those studies were still very expensive.</p></li>\n<li><p><strong>Research that cannot be applied in RCT for any reason, such as limitations of input, treatment scarcity, ethical considerations, etc.</strong></p></li>\n</ul>\n\n<p><strong>Specific examples and references:</strong></p>\n\n<ol>\n<li>Chen H., et al (2014) Lancet. 383(9918):714-21. doi: 10.1016/S0140-6736(14)60111-2. Clinical and epidemiological characteristics of a fatal case of avian influenza A H10N8 virus infection: a descriptive study. <a href=\"https://www.sciencedirect.com/science/article/pii/S0140673614601112\" rel=\"nofollow noreferrer\">https://www.sciencedirect.com/science/article/pii/S0140673614601112</a></li>\n</ol>\n\n<blockquote>\n <p>We report the first human infection with a novel reassortant avian\n influenza A H10N8 virus.</p>\n</blockquote>\n\n<ol start=\"2\">\n<li>Byun M., et al. (2010) J Exp Med. 207(11):2307-12. doi: 10.1084/jem.20101597. Whole-exome sequencing-based discovery of STIM1 deficiency in a child with fatal classic Kaposi sarcoma. <a href=\"http://jem.rupress.org/content/207/11/2307.long\" rel=\"nofollow noreferrer\">http://jem.rupress.org/content/207/11/2307.long</a></li>\n</ol>\n\n<blockquote>\n <p>Whole-exome sequencing-based discovery of STIM1 deficiency in a child\n with fatal classic Kaposi sarcoma.</p>\n</blockquote>\n\n<ol start=\"3\">\n<li>Garrett-Bakelman F.E., et al. (2019) Science. 364(6436). pii: eaau8650. doi: 10.1126/science.aau8650. The NASA Twins Study: A multidimensional analysis of a year-long human spaceflight. <a href=\"https://science.sciencemag.org/content/364/6436/eaau8650.long\" rel=\"nofollow noreferrer\">https://science.sciencemag.org/content/364/6436/eaau8650.long</a></li>\n</ol>\n\n<blockquote>\n <p>[...] significant changes in multiple data types were observed in\n association with the spaceflight period; the majority of these\n eventually returned to a preflight state within the time period of the\n study. These included changes in telomere length, gene regulation\n measured in both epigenetic and transcriptional data, gut microbiome\n composition, body weight, carotid artery dimensions, subfoveal\n choroidal thickness and peripapillary total retinal thickness, and\n serum metabolites.</p>\n</blockquote>\n\n<p><strong>Addressing your specific questions about \"studies of one\", N=1 studies, case studies, or case reports:</strong></p>\n\n<blockquote>\n <p>What does the academic medical field think of this type of paper?</p>\n</blockquote>\n\n<p>It depends on the field, and the quality of the specific study, and can vary a lot between respected, influential, etc, and irrelevant, not even acceptable for publication in high quality journal.</p>\n\n<blockquote>\n <p>Can such a paper be a good paper?</p>\n</blockquote>\n\n<p>Yes, again, depending on the field, and the quality of the specific study.</p>\n\n<blockquote>\n <p>Is it usually considered a \"bad paper\", when compared to a paper that\n has e.g. many patients that received the same treatments, where\n variations and complications are discussed?</p>\n</blockquote>\n\n<p><em>All other things being equal</em>, obviously a case study with N=1 would be inferior to a study with multiple independent patients. In cases like this, N=1 papers would have a hard time getting through peer review in high quality journals, because the reviewers are likely to be aware of the current standards in that specific field, such as RCTs, epidemiological or association studies. I doubt N=1 study on the effects of a well-known statin on cholesterol would be published, if multiple double-blind RCTs are already available on orders of magnitude more patients.</p>\n\n<blockquote>\n <p>Is this sort of paper simply part of the cutting edge of medical\n science, that all results are useful?</p>\n</blockquote>\n\n<p>In the context of this question, one can assume that a high quality case study is indeed \"cutting edge\", and there is a reason why N=1 was the best one could get at the time.</p>\n", "score": 7 }, { "answer_id": 20307, "body": "<p>The difference is that you are looking at a case study, versus a scientific research study.</p>\n\n<p>The basic difference is that a case study is an in depth look at a single instance of something which may not be repeatable by others, and a scientific study is a broader examination of a group with results and experiments that can be repeated by others.</p>\n\n<p>As an example: Your second study is a specific surgical intervention in a case of a man that had a recurrent tumor in a specific spot with malignant pleural mesothelioma. This is not something that is likely to be repeatable over and over by others, but it still worth examining in case it happens again. So it's written up as a case study, and presented as such.</p>\n", "score": 3 } ]
20,306
CC BY-SA 4.0
Is a study of one research in the field of medicine?
[ "research", "practice-of-medicine", "scientific-method" ]
<p>Medicine is not my field, nor do I have mesothelioma. I'm also not seeking any clinical trials or experimental treatment. However, sometimes I find myself trying my read medical papers, either out of sheer interest or if I have a serious complication. I want to stress that I don't think self-diagnosis is a good idea, I just can't help myself sometimes.</p> <p>I find that quite a few papers I get from PubMed appear to be a "study of one". Consider this paper <a href="https://academic.oup.com/ejcts/article/41/6/1393/420831" rel="nofollow noreferrer">https://academic.oup.com/ejcts/article/41/6/1393/420831</a></p> <p>Or this: <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5728971/" rel="nofollow noreferrer">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5728971/</a></p> <p>I'm not saying this is a bad paper, I have no idea. However, I am curious as to how common and accepted this type of paper is within the field of medicine.</p> <p>On one hand, I can see that for pushing the limits of surgery, or any technique, it is interesting to see what people have had success with, even if it is just one patient. On the other hand, it is just one patient. How can anything be generalized from this?</p> <p>Is there a difference between treatment with medications and surgical technique? I can imagine that surgical techniques can be replicated with far more accuracy than results from medication, which are plagued by placebo and unclear method of operation (I'm making this stuff up, so please correct me).</p> <p>Again, I have no grounds of criticizing the work of either of the papers, they are just used as examples, and as mentioned, there are quite a few such papers. Indeed, if I do a search for "we present a case of", I get a ton of results for actual papers that lead with this. I'm sure there are many other, similar phrases that are also used for these single study cases.</p> <p>My question is simply, what does the academic medical field think of this type of paper? Can such a paper be a good paper? Is it usually considered a "bad paper", when compared to a paper that has, for example, many patients that received the same treatments, where variations and complications are discussed? Is this sort of paper simply part of the cutting edge of medical science, that all results are useful?</p>
7
https://medicalsciences.stackexchange.com/questions/20822/does-brushing-your-teeth-immediately-after-sleeping-have-some-medical-significan
[ { "answer_id": 20823, "body": "<p>The <a href=\"https://www.nhs.uk/live-well/healthy-body/how-to-keep-your-teeth-clean/\" rel=\"noreferrer\">NHS says</a> (emphasis mine)</p>\n\n<blockquote>\n <p>Brush your teeth for about 2 minutes last thing at night before you go to bed <strong>and on 1 other occasion every day</strong>. </p>\n</blockquote>\n\n<p>They don't specifically stipulate as soon as you get up or after breakfast, but <a href=\"https://www.dhamadison.com/news/do-i-really-need-to-brush-my-teeth-twice-a-day\" rel=\"noreferrer\">brushing in the morning is important</a> because</p>\n\n<blockquote>\n <p>during the night, the formation of plaque is mostly undisturbed. Brushing after each meal is also endorsed by many dentists.</p>\n</blockquote>\n\n<p>However, be careful when you brush. It is best to brush after meals, but the <a href=\"https://www.dentalhealth.org/dental-erosion\" rel=\"noreferrer\">British Oral Health Foundation</a> says:</p>\n\n<blockquote>\n <p>Every time you eat or drink anything acidic, the enamel on your teeth becomes softer for a short while, and loses some of its mineral content. Your saliva will slowly cancel out this acidity in your mouth and get it back to its natural balance.<br>\n <strong>[...]</strong><br>\n Wait for at least one hour after eating or drinking anything acidic before brushing your teeth. This gives your teeth time to build up their mineral content again.</p>\n</blockquote>\n\n<p>Brushing immediately afterward wears\nthe enamel away, and can cause dental erosion, which may lead to pain and extreme sensitivity in the teeth.</p>\n\n<p>Whenever you brush your teeth, <a href=\"https://medicalsciences.stackexchange.com/a/18234/7951\">don't rinse your mouth with water after</a> because you will rinse away the fluoride provided by the toothpaste used, flushing away the preventative nature of toothpaste.</p>\n", "score": 7 } ]
20,822
CC BY-SA 4.0
Does brushing your teeth immediately after sleeping have some medical significance?
[ "dentistry", "brushing-teeth" ]
<p>Context:</p> <p>I have generally only brushed my teeth once-a-day, before going to bed.</p> <p>My dentist has advised to start brushing twice a day, adding "immediately in the morning" to my dental routine.</p> <p>I don't eat breakfast in the morning, and told the dentist that, and they confirmed that first thing in the morning was still the recommendation.</p> <p>I didn't press them more, but now wish that I had done so.</p> <hr> <p>I would have assumed that (generally speaking) brushing at 12-hourly intervals would be the more beneficial than brushing twice, 8 hours apart, and then not brushing for 16 hours.</p> <p>Since I go to bed at ~11:30pm, therefore if I'm going to brush again, and I don't eat breakfast, then I'm better off brushing around 11:00am, or just before lunch.</p> <p>I can see 2 possibilities for why that might not be the case:</p> <ul> <li><p><strong>Physiological</strong>: Sleep does something to the mouth, that means it's beneficial to clean it immediately after waking.</p></li> <li><p><strong>Psychological</strong>: In practice, people are more successful at adding steps to a morning routine, so if they're told to do it 1st-thing, then they're more likely to <em>actually</em> do it. Hence, if I think I can reliably do it in the late morning, then I should do <em>that</em>, instead.</p></li> </ul> <p>The latter seems <em>very</em> likely to be true.</p> <p>But is the former option <strong>also</strong> true?</p> <p><strong>Is there any medical significance to brushing your teeth after waking up, if you're not going to eat until lunch?</strong></p>
7
https://medicalsciences.stackexchange.com/questions/21156/why-are-people-so-worried-about-2019-ncov
[ { "answer_id": 21205, "body": "<p>The danger posed to society from this disease doesn't come from the mortality rate, rather from the potential to make large fraction of the population ill. Unlike the flu virus, this virus is a new virus to which we have no immunity.</p>\n\n<p>About 10% of the infected people requires hospital treatment, which is a lot higher than in case of flu. The death rate of the order of 1% is achieved thanks to excellent hospital treatment. With a far larger fraction of the population infected with this virus compared to the flu and a far larger fraction of the infected people requiring hospital treatment compared to flu, the available hospital capacity to give everyone the treatment they need can be easily exhausted. The death rate due to the virus will then increase.</p>\n\n<p>Also, people who need treatment for other reasons can then also fail to get prompt medical attention. People suffering a heart attack who would have survived under normal circumstances thanks to getting prompt medical attention, may now end up dying too. </p>\n", "score": 5 }, { "answer_id": 21208, "body": "<p>If we compare Covid19 to SARS or MERS - COVID19 seems to have a R0 slightly higher than SARS but lower than MERS. From various sources it appears that COVID-19 could be between 2 and 7, so compariable to diseases such as mumps and diphtheria in spread. Infection fatality rates vary wildly right now as the sample size is very small, but from 0.2% up to 18% (18% for early stage Hubei province infections). </p>\n\n<p>Comparisons to other diseases:-<a href=\"https://en.wikipedia.org/wiki/Herd_immunity\" rel=\"nofollow noreferrer\">Wiki-herd immunity</a> - I wanted to paste the table in here, but SE doesn't seem to support the MD table format</p>\n\n<p>refs:-</p>\n\n<ul>\n<li><a href=\"http://currents.plos.org/outbreaks/index.html%3Fp=40801.html\" rel=\"nofollow noreferrer\">http://currents.plos.org/outbreaks/index.html%3Fp=40801.html</a></li>\n<li><a href=\"https://wwwnc.cdc.gov/eid/article/26/2/19-0697_article\" rel=\"nofollow noreferrer\">https://wwwnc.cdc.gov/eid/article/26/2/19-0697_article</a></li>\n<li><a href=\"https://wwwnc.cdc.gov/eid/article/10/7/03-0647_article\" rel=\"nofollow noreferrer\">https://wwwnc.cdc.gov/eid/article/10/7/03-0647_article</a></li>\n<li><a href=\"https://www.who.int/news-room/detail/23-01-2020-statement-on-the-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-outbreak-of-novel-coronavirus-(2019-ncov)\" rel=\"nofollow noreferrer\">https://www.who.int/news-room/detail/23-01-2020-statement-on-the-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-outbreak-of-novel-coronavirus-(2019-ncov)</a></li>\n</ul>\n\n<p>But IMO the primary difference is that SARS and MERS occured before large-scale social-media monetization.. So there was little to gain by media/social media doing a major panic.. </p>\n", "score": 1 } ]
21,156
Why are people so worried about 2019-nCoV?
[ "virus", "public-health" ]
<p><strong>EDIT</strong>: After reading the comments and learning more about the current outbreak, I see that the premise of my question is incorrect. I mistakenly believed that the virus' mortality rate was around the same as that of the flu, when in fact it's much higher.</p> <hr> <p>My understanding is that the virus' mortality rate is around 2%, which is similar to the flu. It's less deadly than SARS.</p> <p>So why are people so worried, and why are governments going to such extreme measures to prevent it from spreading? My guesses are:</p> <ul> <li>We don't know enough about the long-term effects of the virus, so better safe than sorry</li> <li>The economic and social disruption caused by robust measures (e.g., quarantining) costs less than letting a new disease become pandemic, even if it isn't particularly deadly</li> <li>Mass hysteria fueled by the media and misinformation</li> <li>Governments feeling like they have to appear responsive to popular concern lest they seem lazy</li> <li>This virus affects more developed parts of the world, so it's more visible</li> <li>The Chinese government's over-the-top, authoritarian, "only in China"-style measures have left everyone in such awe that they think, "this must be really serious!" (When in fact the government's real intention is perhaps to cover up how badly they botched their initial handling of the outbreak.)</li> </ul> <p>As for one's chances of coming into contact with the virus, the total number of confirmed cases in the world as of writing is around 80k. Let's say that the true number is double that, or 160,000. That's still only ~1.5% of the population of Wuhan, the city where the initial outbreak occurred. Why should anyone be in the slightest bit concerned about going for a stroll down the main street?</p> <p>I'm not an expert in public health or medicine. It would be great to hear an expert's take on this question!</p>
7
https://medicalsciences.stackexchange.com/questions/21198/what-protects-chinese-provinces-other-than-hubei-from-covid-19-outbreak
[ { "answer_id": 21211, "body": "<p>I live in Guangdong, and this is what I've been seeing &amp; reading about.</p>\n\n<p>Wuhan (city in Hubei) is where the outbreak supposedly began. And it went unnoticed for a while, which mean it was spreading locally more-so than it was spreading nationally/internationally. Near at the start of the Chinese New Year holiday, the government decided to quarantine all of Hubei province. So while other provinces already had infected people, they spread hadn't grown as significantly as it had in Hubei yet.</p>\n\n<p>The Chinese government then decided to take specific measures to control the epidemic. For starters, they required mask-wearing and encouraged staying indoors. They also began to set up body temperature checks all over the place (apartments, neighborhoods, roads leading into cities, and places of work once the holiday ended. Fever seems to be the first symptom, so this is why).</p>\n\n<p>If anyone in an apartment building was confirmed to have the virus, then the entire building and all residents were/are quarantined for 14 days (happened to a 30+ story apartment building next to mine). Elevators, doors, and other public spaces are often disinfected, particularly if a suspected case had been in the area. Again, I saw this at a temperature checkpoint, someone must've had a fever and a little bit later some folks came and sprayed down the area.</p>\n\n<p>Schools are also closed in all provinces across the country, and students are doing online schooling. Some companies are also allowing employees to work from home, or 'staggering' their work days (half come in into the office on Mon, Wed, Fri, the other half come in Tuesday and Thursday). This decreases the number of people a possible infected person can pass the virus to.</p>\n\n<p>On top of this, companies needed to 'apply' to be able to resume work. Here in Shenzhen, nobody could return to work within 14 days of returning from the city, assuming they left during the holiday. We also need to record down our body temp when coming to and leaving from work. According to an SMS I received from the local government, if 2 employees have a body temperature >= 37.3C, then it needs to be reported immediately, as it indicates a possible spread in that workplace.</p>\n\n<p>In short, the virus was able to take a foothold in Hubei, and it was noticed before it took a significant foothold in other provinces. Therefore other provinces had time to implement proactive and preventative measures, before the situation grew to Hubei-level of significance.</p>\n\n<p>The best way to prevent it from spreading is simple steps, such as not going outside unless its necessary, avoid close contact with others (defined as within 6 feet for an extended period of time), washing your hands, and disinfecting often-touched surfaces like door knobs, keyboards, cell phones, etc. It remains to be seen whether other countries will take the same rather drastic measures that are being taken in China, I suppose it all depends on how bad things get in other countries.</p>\n", "score": 10 }, { "answer_id": 21589, "body": "<blockquote>\n<p>“The biggest conclusion is that China has demonstrated that the course of the outbreak can be altered. Normally, an outbreak of this nature would have exponential growth, would reach a high peak, and would then decline naturally once all susceptible people have been infected, or developed the disease. This has not happened in China in a number of ways,” he said.</p>\n<p>“One: the shape of the course of the events - the graph, the epidemic curve, as we call it, of the numbers of cases over time - appears very unnatural. It is an epidemic that has been nipped as it was growing and stopped in its tracks. This is very clear from the data that we have, as well as the observations that we can see in society in general.</p>\n<p>&quot;So, that's a big lesson that the natural course of the outbreak does not need to be a very high peak that overrwhelms health services. This lesson in containment, therefore, is a lesson that other countries can learn from and adapt for their own circumstances&quot;.</p>\n</blockquote>\n<p>China acheived this feat in Hubei through the ruthless application of science and knowledge of infection control. In the absence of a known treatment, the standard measure from centuries of history is containment and isolation in the containment regions.</p>\n<p>They totally shut the borders to Wuhan, a city of 8 million people as well as other cities in the province of Hubei. This type of action has never been done in the history of mankind before. The border controls were put in place even before there was any stress on the health systems in Hubei Province. The onset of the pandemic was at the start of the Lunar Holidays which is the world's largest single yearly migration and this was shut down to stop the spread of virus.</p>\n<p>All the cities in China were basically shut down so that even in Urumqi in the far western border, people were not allowed on the streets without good cause. Any threat to the confined Muslim population was also eliminated in this way.</p>\n<p>This allowed medical staff all over China sufficient time to contact trace all infections, as well as gave them time to do case discovery as well as unprecedented actions ( random temperature checks, daily reporting of your temperature, tracing the movement of every citizen, separating every restaurant user from each other by barriers etc ) to stop the spread of the virus. There was mass movement of medical staff from Beijing and other centres to Wuhan to help control/treat the sick, and 1000 bed hospitals were built over the course of a week or so.</p>\n<p>This is how China protected the other provinces from the infection. The Chinese govt has called the citizens of Wuhan heroes for enduring such harsh measures which have protected the other billion citizens.</p>\n<p>Of course there is another story to all of this .. people left to die at home unable to access hospital care, a child with cerebral palsy who died at home as both parents had died and there was no one to care for him and other stories of immense human tragedy. And we must not forget our companions, the 10s of 1000s of pets left to starve as people were moved from apartments to isolation camps, and the efforts made to save them.</p>\n<p><a href=\"https://news.un.org/en/story/2020/03/1059502\" rel=\"nofollow noreferrer\">https://news.un.org/en/story/2020/03/1059502</a></p>\n<p><a href=\"https://www.nationalreview.com/news/coronavirus-wuhan-official-called-for-gratitude-education-to-teach-citizens-to-thank-xi-jinping-for-response/\" rel=\"nofollow noreferrer\">https://www.nationalreview.com/news/coronavirus-wuhan-official-called-for-gratitude-education-to-teach-citizens-to-thank-xi-jinping-for-response/</a></p>\n<p><a href=\"https://www.hongkongfp.com/2020/03/17/hero-coronavirus-crisis-china-according-state-propaganda/\" rel=\"nofollow noreferrer\">https://www.hongkongfp.com/2020/03/17/hero-coronavirus-crisis-china-according-state-propaganda/</a></p>\n", "score": 6 } ]
21,198
CC BY-SA 4.0
What protects Chinese provinces other than Hubei from COVID-19 outbreak?
[ "covid-19" ]
<p>In China, the largest number of reported COVID-19 infections was in Hubei province.</p> <p>Other countries are experiencing exponential increase in reported infections, while the remainder of China is reporting relatively small numbers of cases<sup><a href="https://github.com/CSSEGISandData/COVID-19/blob/master/csse_covid_19_data/csse_covid_19_time_series/time_series_19-covid-Confirmed.csv" rel="noreferrer">source_1</a></sup></p> <p>What protects Chinese provinces other than Hubei from COVID-19 outbreak?</p> <ul> <li>What is different about the remainder of China compared to the rest of the world?</li> <li>Is there anything we can learn from the provinces in China that so far were less affected by the virus than Hubei?</li> </ul>
7
https://medicalsciences.stackexchange.com/questions/21355/what-is-the-expected-false-positives-negatives-for-covid-19-tests
[ { "answer_id": 21380, "body": "<p>See long answer for <a href=\"https://medicalsciences.stackexchange.com/q/21337/7951\">How accurate are coronavirus tests?</a></p>\n\n<p>With the \"worst-case numbers\" from there which I take from the minimum performance requirements the FDA currently uses with an emergency validation to allow labs to quickly implement Covid-19 tests without undergoing the full validation procedure they normally take, we have LR+ ≈ 11 and LR- ≈ 1/20.</p>\n\n<p>The tests may be (and probably are) actually much better.</p>\n\n<p>If we take 71 positive : 478 negative tests as a surrogate for the prevalence of Covid-19 infected among the tested population (14.5 %), the post-test probabilities of having Covid-19 are</p>\n\n<ul>\n<li><p>71 : 478 * 11 = 781 : 478 ≈ 5 : 3 for those who tested positive, i.e. ≈ 62 % PPV or post-test probability of having Covid-19.<br>\nThus, as many as 38 % of the 71 or 27 <em>could</em> be false positives.</p></li>\n<li><p>71 : 478 * 1/20 = 71 : 9560 ≈ 1 : 135 or 0.7 % post-test probability of nevertheless really having Covid-19.<br>\nI.e. up to maybe 1 false negative case.</p></li>\n</ul>\n\n<hr>\n\n<p>Update: I've updated the linked answer since I've meanwhile found more detailed data on the actual validation performed for several tests. \nMost of them used more than the minimum required sample size, but it's not that 1000s of validation samples were run. (The infamous CDC test got emergency approval after only 13 positive validation cases, though, so even less. But that was beginning of Feb, and they may not have had more test samples available at that time)</p>\n\n<p>If we want to calculate with expected instead of worst-possible performance for e.g. the Thermo Fisher test, LR+ and LR- would be 61 and 1/61, respectively. </p>\n\n<p>PPV would then have been 90 % (7 false positives) and NPV 0.25 % (0 false negatives). </p>\n", "score": 1 }, { "answer_id": 23722, "body": "<p>The published numbers probably based on the <a href=\"https://en.wikipedia.org/wiki/Reverse_transcription_polymerase_chain_reaction\" rel=\"nofollow noreferrer\">PCR</a> test. About the PCR I has found some information few time ago.</p>\n\n<p>At first it is to consider that there is only a certain period in which a sample from a certain area shows results in the PCR. For throat swab samples <a href=\"https://pubs.rsna.org/doi/10.1148/radiol.2020200642\" rel=\"nofollow noreferrer\">was found</a> that it can take <strong>4 to 8 days</strong> for an existing infection to be displayed with PCR. The time period in which the test remains positive is limited to <strong>4 to 15 days</strong>, although the disease continued to develop. <a href=\"https://www.medrxiv.org/content/10.1101/2020.02.11.20021493v2.full.pdf\" rel=\"nofollow noreferrer\">Now</a> nasal samples are recommended before taking a throat swab, but there will also be a suitable period for sampling.</p>\n\n<p>In expansion, how accurate are the PCR tests in the period in which the tests should reliable be positive. There is a <a href=\"https://link.springer.com/content/pdf/10.1007/s11427-020-1661-4.pdf\" rel=\"nofollow noreferrer\">study</a> in which PCR tests were carried out daily. There is shown that inside of period with positive results, some tests produced a negative result.\nThe days only from first day with a positive result to the last day with a positive result gives a total period of 84 days over all patients. During this time, also 11 tests with negative results were produced. This gives a value of <strong>13.7%</strong> negative test results, even though the patient was infected with COVID-19.</p>\n\n<p>It must be noted that PCR testing is not a simple yes/no test. The result first depends whether a sufficient number of viruses is obtained.</p>\n\n<ul>\n<li>As written above, it is important to choose the correct region of body.</li>\n<li>It must be the relevant time at which the viruses are in the selected region.</li>\n<li>The sample must be obtained in the correct manner.</li>\n<li>The viral load in the patient himself has to be suffice (<a href=\"https://www.medrxiv.org/content/10.1101/2020.03.24.20042689v1\" rel=\"nofollow noreferrer\">medrxiv.org</a>)</li>\n</ul>\n\n<p><a href=\"https://academic.oup.com/clinchem/advance-article/doi/10.1093/clinchem/hvaa099/5819547\" rel=\"nofollow noreferrer\">Here</a> is described that for a number of 484 copies of SARS-CoV-2 RNA per milliliter some PCR test products detect SARS-CoV-2 with <strong>100%</strong> but one other of the approved products detects <strong>0%</strong> of virus.</p>\n\n<p>So there is not the one accuracy. It is to be asked which type of test kit was used by which manufacturer, who took how the sample, etc. Every single item can significantly impact the accuracy of a test.</p>\n", "score": 0 } ]
21,355
CC BY-SA 4.0
What is the expected false positives/negatives for COVID-19 tests?
[ "covid-19", "diagnosis", "test-results", "united-states" ]
<p>As of March 13, <a href="https://www.nbcmiami.com/news/local/15-new-cases-of-coronavirus-announced-in-florida/2204960/" rel="nofollow noreferrer">45/301 people have tested positive/negative for COVID-19 in Florida</a>. What is the expected false positives/negatives here?</p> <p>UPDATE (March 14): 71/478 from what I consider <a href="http://www.floridahealth.gov/diseases-and-conditions/COVID-19" rel="nofollow noreferrer">the best source</a>.</p>
7
https://medicalsciences.stackexchange.com/questions/21357/why-does-covid-19-appear-more-infectious-than-sars
[ { "answer_id": 21422, "body": "<p>The viruses are acting differently. SARS-CoV-2 virus is much more infectious with a much higher viral replication rate, and with people exhaling the virus in the pre-symptomatic phase whereas SARS this was not happening. Once the infected individual becomes symptomatic their bodies are producing antibodies which helps shut down viral particle shedding though virus is still being transmitted by cough which aerolizes the virus at a further distance then just by exhalation.</p>\n<blockquote>\n<p>The nine patients, who were admitted to the same Munich hospital, were studied because they had had close contact with an index case. Cell cultures and real-time polymerase chain reaction (RT-PCR) were done on throat swabs and samples of sputum, stool, blood, and urine. Throat swabs showed very high viral shedding during the first week of symptoms.</p>\n<p>The findings contrasted starkly with those from the 2003 outbreak of SARS in terms of viral load. &quot;In SARS, it took 7 to 10 days after onset until peak RNA concentrations (of up to 5x105 copies per swab) were reached,&quot; the researchers wrote. &quot;In the present study, peak concentrations were reached before day 5, and were more than 1,000 times higher.&quot;</p>\n</blockquote>\n<p>but the mean incubation period is 5 days.</p>\n<p><a href=\"http://www.cidrap.umn.edu/news-perspective/2020/03/study-highlights-ease-spread-covid-19-viruses\" rel=\"noreferrer\">http://www.cidrap.umn.edu/news-perspective/2020/03/study-highlights-ease-spread-covid-19-viruses</a></p>\n", "score": 6 }, { "answer_id": 21359, "body": "<p>It is possible that with SARS fewer people were transmitting the virus, but those who were were \"super-spreaders\". R_0 is an average of those transmitting.</p>\n\n<p>Source:</p>\n\n<p><a href=\"http://www.cidrap.umn.edu/news-perspective/2020/01/data-suggest-ncov-more-infectious-1918-flu-what-does-mean\" rel=\"nofollow noreferrer\">http://www.cidrap.umn.edu/news-perspective/2020/01/data-suggest-ncov-more-infectious-1918-flu-what-does-mean</a></p>\n\n<p>Another possibility is that the high mortality rate in SARS actually prevented it from spreading widely.</p>\n\n<p>Source:</p>\n\n<p><a href=\"http://nautil.us/issue/83/intelligence/the-man-who-saw-the-pandemic-coming\" rel=\"nofollow noreferrer\">http://nautil.us/issue/83/intelligence/the-man-who-saw-the-pandemic-coming</a></p>\n", "score": 2 } ]
21,357
CC BY-SA 4.0
Why does COVID-19 appear more infectious than SARS?
[ "covid-19" ]
<p>The COVID-19 R0 factor is 2-3, while SARS had an R0 factor of 2-5. However, COVID-19 has infected around 130,000 people and growing, while SARS totalled just under 9000 people infected.</p> <p>Why is COVID-19 spreading faster and wider than SARS? What other factors have let COVID-19 reach pandemic levels, while SARS was contained and eradicated? Could the R0 factor be higher than believed? Was it initially slower to be contained?</p> <p>Full disclosure, I'm not in medicine or a medical scientist. I'm a software developer and data scientist, and this has piqued my interested in the spread of infectious disease.</p>
7
https://medicalsciences.stackexchange.com/questions/21536/are-there-any-central-trackers-for-covid-19-trials
[ { "answer_id": 21553, "body": "<p>I think you're asking about trials</p>\n\n<p>See the <a href=\"https://clinicaltrials.gov/ct2/results?cond=covid-19&amp;term=&amp;cntry=&amp;state=&amp;city=&amp;dist=\" rel=\"nofollow noreferrer\">clinical trials database</a></p>\n", "score": 3 }, { "answer_id": 23028, "body": "<p>Such a tracker is available on the <a href=\"https://milkeninstitute.org/covid-19-tracker\" rel=\"nofollow noreferrer\">Milken Institute website</a>. It currently lists 52 vaccine candidates and 79 treatment candidates.</p>\n<p>Update: one month later (May 4th) it lists 123 vaccine candidates and 199 potential treatments. Incredible!</p>\n<p>Update #2: there are now 202 vaccine candidates and 316 potential treatments, as of August 8th</p>\n", "score": 3 }, { "answer_id": 24385, "body": "<p>As far as treatments are concerned, there is <a href=\"https://www.covid-trials.org/\" rel=\"nofollow noreferrer\">https://www.covid-trials.org/</a>. It allows you to filter results by trial status (completed, recruiting, etc.), treatment and location. It also has links to trial results (where available) and registry information.</p>\n<p>It does not have information on vaccine candidates, though.</p>\n<p><strong>Reference:</strong></p>\n<p>Thorlund A, Dron L, Park J, et al. A real-time dashboard of clinical trials for COVID-19. The Lancet Digital Health [Internet]. 2020 Apr 24 [cited 2020 Aug 9];2(6):E286–E287. Available from: <a href=\"https://www.thelancet.com/journals/landig/article/PIIS2589-7500(20)30086-8/fulltext\" rel=\"nofollow noreferrer\">https://www.thelancet.com/journals/landig/article/PIIS2589-7500(20)30086-8/fulltext</a></p>\n", "score": 3 }, { "answer_id": 25924, "body": "<p>One more tracker for COVID-19 trials: <a href=\"https://covid19.trackvaccines.org/trials-vaccines-by-country/\" rel=\"nofollow noreferrer\">https://covid19.trackvaccines.org/trials-vaccines-by-country/</a> (<a href=\"https://web.archive.org/web/20210226194811/https://covid19.trackvaccines.org/trials-vaccines-by-country/\" rel=\"nofollow noreferrer\">mirror</a>).</p>\n<p><a href=\"https://i.stack.imgur.com/5Jg5r.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/5Jg5r.png\" alt=\"enter image description here\" /></a></p>\n", "score": 0 } ]
21,536
CC BY-SA 4.0
Are there any central trackers for COVID-19 trials?
[ "medications", "covid-19", "vaccination" ]
<p>There are several aggregate central trackers for the spread of COVID-19. <a href="https://www.worldometers.info/coronavirus/" rel="noreferrer">Like this one, for example.</a></p> <p>Is there anything similar for trials? Or trials in the pipeline? Either vaccines or treatments?</p>
7
https://medicalsciences.stackexchange.com/questions/21568/can-cpap-devices-connected-with-oxygen-sources-be-used-as-ventilators
[ { "answer_id": 21573, "body": "<p>The software is very different. And the capabilities of the machine. The monitoring parameters within Ventilators are much more sensitive to pressure and volume than CPAP or BIPAP machines. Below are two pages from the manufacturer with setting capabilities for a BIPAP and a ventilator.</p>\n\n<p><a href=\"https://www.usa.philips.com/c-p/HH1460_00/dreamstation-cpap-with-humidifier\" rel=\"nofollow noreferrer\">https://www.usa.philips.com/c-p/HH1460_00/dreamstation-cpap-with-humidifier</a></p>\n\n<p><a href=\"https://www.usa.philips.com/healthcare/product/HCNOCTN96/respironics-v60-non-invasive-ventilator/specifications\" rel=\"nofollow noreferrer\">https://www.usa.philips.com/healthcare/product/HCNOCTN96/respironics-v60-non-invasive-ventilator/specifications</a></p>\n", "score": 4 }, { "answer_id": 21569, "body": "<p>The essence of protection is a physical barrier against air borne virus droplets splashing against your mucus membranes (eyes, nose, mouth), and against virus from being breathed in. A CPAP machine offers none of these. Even if connected to an oxygen supply some CPAP machines are just nasal and don't stop the person using their mouths. The oxygen supply needs to be mixed with air, and that air needs to be filtered for any kind of protection.</p>\n\n<p>That is my educated guess.</p>\n", "score": 2 }, { "answer_id": 21582, "body": "<p>The American Academy of Sleep Medicine (AASM) is correct in what they are saying when <a href=\"https://aasm.org/coronavirus-covid-19-faqs-cpap-sleep-apnea-patients/\" rel=\"nofollow noreferrer\">they said that</a></p>\n<blockquote>\n<p>It is possible that using CPAP could increase the risk of spreading the virus to others around you.</p>\n</blockquote>\n<p>If you are suffering from COVID-19 and use a CPAP machine, the air around you is sucked into the machine and blown out of the mask. Excess air pressure is blown out of outlet holes in the elbow joint between the tubing and mask. This can carry the COVID-19 pathogen out with it at force, spreading it further around the room.</p>\n<p>Take <a href=\"https://shop.resmed.com/medias/sys_master/images/images/hfa/hef/8835700817950/p-EU-63494-ResMed-QuietAir-Quiet-CPAP-Mask-Elbow-01-Medium.jpg\" rel=\"nofollow noreferrer\">this elbow joint as example</a>, used on my CPAP mask.\n<a href=\"https://i.stack.imgur.com/X5lyC.jpg\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/X5lyC.jpg\" alt=\"CPAP mask elbow joint\" /></a></p>\n<p>When you take where the idea of using oxygen and air supplies comes from</p>\n<blockquote>\n<p>... if demand continues to grow, hospitals could use sleep apnea machines, <strong>suggests George Washington University Law professor John Banzhaf</strong></p>\n</blockquote>\n<p>This quote from the 2nd website (<a href=\"https://www.coronavirustoday.com/cpap-machines-treat-sleep-apnea\" rel=\"nofollow noreferrer\">an article supposedly checked by an MD</a> in Coronavirus Today) highlights that this is a hypothesis from a non medical professor. He may have experience working within the field of medicine but he is a medical negligence lawyer, not a medical practitioner, as highlighted by <a href=\"https://www.law.gwu.edu/john-f-banzhaf-iii\" rel=\"nofollow noreferrer\">his George Washington University Law page</a></p>\n<p>The idea of using an oxygen and air supply is &quot;thinking outside the box&quot; but not viable from my knowledge of CPAP/APAP machines. CPAP and APAP machines take air from the surrounding air through a filter on the side of the machine.</p>\n<p>Take for example, my CPAP machine air intake photographed in this image</p>\n<p><a href=\"https://i.stack.imgur.com/ub2Ku.jpg\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/ub2Ku.jpg\" alt=\"CPAP air intake\" /></a></p>\n<p>There is no way of connecting a bottled oxygen and air supply to this air inlet.</p>\n<h2>Using oxygen and air supply between the machine and mask</h2>\n<p>You said in the comments:</p>\n<blockquote>\n<p>I checked that as well and there is an easy way to connect oxygen. If the CPAP is not oxygen compatible, you can add an oxygen bleed adaptor between the machine tubing and the mask tubing.</p>\n</blockquote>\n<p>If you are looking to add oxygen within the air supplied to the patient, you are correct that <a href=\"https://www.cpap.com/blog/complete-guide-using-cpap-oxygen/\" rel=\"nofollow noreferrer\">you can connect an adaptor</a> between the machine and the tubing to the mask.</p>\n<p>If you are wanting to maintain a specific oxygen concentration, the way CPAP/APAP machines work is different to hospital ICU (Intensive Care Unit) ventilators.</p>\n<blockquote>\n<p>Ventilators employed in NIV [Non-Invasive Ventilation] range from ICU ventilators with full monitoring and alarm systems normally employed in the intubated patient, to light weight, free standing devices with limited alarm systems specifically designed for non-invasive respiratory support. Life support ICU ventilators separate the inspiratory and expiratory gas mixtures. This prevents rebreathing and allows monitoring of inspiratory pressure and exhaled minute ventilation on which monitoring and alarm limits are based (British Thoracic Society Standards of Care Committee, 2002).</p>\n</blockquote>\n<h2>References</h2>\n<p>British Thoracic Society Standards of Care Committee. (2002). Non-invasive ventilation in acute respiratory failure. <em>Thorax, 57</em>(3), 192. DOI: <a href=\"https://doi.org/10.1136/thorax.57.3.192\" rel=\"nofollow noreferrer\">10.1136/thorax.57.3.192</a> PMCID: <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1746282/\" rel=\"nofollow noreferrer\">PMC1746282</a></p>\n", "score": 2 } ]
21,568
CC BY-SA 4.0
Can CPAP devices connected with oxygen sources be used as ventilators?
[ "covid-19", "oxygen", "cpap" ]
<p>I want to inquire if CPAP devices can act as low performance ventilators, if they are connected to an oxygen source as well.</p> <p>I am asking this question in regards to the covid-19 pandemic. There are only two websites which cover this in the entire web. One of them only suggests that CPAP devices <a href="https://aasm.org/coronavirus-covid-19-faqs-cpap-sleep-apnea-patients/" rel="noreferrer">may increase the risk of spreading</a>. <a href="https://www.coronavirustoday.com/cpap-machines-treat-sleep-apnea" rel="noreferrer">The other one</a> notes similarities between these devices. Due to the lack of discussion reachable via google, even if the answer is "no", it might help many people.</p> <p>I am looking for</p> <ol> <li>Scientific publications</li> <li>Conventions used in field hospitals/healthcare</li> <li>Your professional educated guess</li> </ol> <p>in this order. Please include which category your answer falls into.</p>
7
https://medicalsciences.stackexchange.com/questions/21744/does-bleach-have-to-be-diluted-to-be-more-effective-to-kill-virus
[ { "answer_id": 21756, "body": "<p>The text does <strong>not</strong> say that <strong>more diluted</strong> bleach is <strong>more effective</strong> at killing viruses (or bacteria, or yeast, for that matter). </p>\n\n<p>I'm quoting:</p>\n\n<p>...A tenfold dilution of bleach, which subsequently mixed with an equal volume of RSV-containing medium (so in fact a <strong>twentyfold dilution</strong>) <strong>eradicated all of the virus</strong>. A <strong>100-fold dilution</strong> of bleach <strong>killed 100% of the virus half of the time</strong>, and <strong>decreased the number of live viral particles by greater than three logs in the other half of the tests</strong>. This was all after five minutes of treatment...</p>\n\n<p>So a 20-fold dilution kills all virus always; a 100-fold dilution kills 100% of the virus 50% of the time and kills most of them in the other cases. </p>\n\n<p>I think form this we can conclude that more highly concentrated bleach is more deadly to viruses than more diluted bleach. </p>\n", "score": 4 }, { "answer_id": 21746, "body": "<p>Household bleach is usually at 5% concentration of sodium hypochlorite. Data from disinfection of other coronaviruses indicates that dilutions of 1:100 are still effective. Higher concentrations of bleach are difficult to manage as they release chlorine gas and are irritant to the mucous membranes, lungs and eyes.</p>\n\n<p>The bleach works as a potent oxidizer of the viral capsule and its contents. <strong>The oxidation relies on the amount of free chlorine molecules available</strong> which is why bleach solutions need to be made up and used in 24 hours as potency drops with time. Normal contact time is 30 seconds to 10 minutes for most microorganisms.</p>\n\n<p>So, this clearly means the higher the concentration the greater the efficacy, but also the greater the risk to the user on account of off gassing of chlorine gas.</p>\n\n<p>Alcohol is different. It requires water to enter the virus so that is why more than 95% concentrations are not recommended. But chlorine just needs to oxidize the outside of the virus to disrupt the viral capsule, and then that opens up the virus RNA which can then be oxidized.</p>\n\n<p><a href=\"https://www.ncbi.nlm.nih.gov/books/NBK214356/\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/books/NBK214356/</a></p>\n\n<p><a href=\"https://ehs.unc.edu/files/2015/09/coronavirus.pdf\" rel=\"nofollow noreferrer\">Use of 10% Ultra Chlorox regular bleach mixed with liquids containing virus to give 5% final concentration</a> to treat coronavirus waste.</p>\n\n<p><a href=\"https://cen.acs.org/biological-chemistry/infectious-disease/How-we-know-disinfectants-should-kill-the-COVID-19-coronavirus/98/web/2020/03\" rel=\"nofollow noreferrer\">https://cen.acs.org/biological-chemistry/infectious-disease/How-we-know-disinfectants-should-kill-the-COVID-19-coronavirus/98/web/2020/03</a></p>\n", "score": 3 } ]
21,744
CC BY-SA 4.0
Does bleach have to be diluted to be more effective to kill virus?
[ "virus", "infectious-diseases", "coronavirus", "disinfection" ]
<p>This page <a href="https://www.scripps.edu/newsandviews/e_20060213/bleach.html" rel="noreferrer">Bleach</a> claims </p> <blockquote> <p>Bleach is more effective at killing germs when diluted than when used straight out of the bottle.</p> </blockquote> <p>this other page (Spanish) <a href="http://www.prensa.mendoza.gov.ar/coronavirus-alcohol-y-lavandina-son-mas-efectivos-si-se-diluyen-en-agua/" rel="noreferrer">Alcohol and Bleach are more effective against Coronavirus diluted</a> claims the same</p> <blockquote> <p>Disinfectants like bleach and alcohol alter the virus structure and prevent it from infecting us. Their effects will depend in the right concentration</p> </blockquote> <p>But this other page, <a href="http://madsci.org/posts/archives/2013-01/1359009191.Cb.r.html" rel="noreferrer">Does liquid bleach has to be diluted to be effective as a virus killer?</a></p> <p>claims </p> <blockquote> <p>So, all things being equal, undiluted bleach is more effective at killing stubborn bacteria.</p> </blockquote> <p>I know, he says bacteria and not virus but, </p> <blockquote> <p>The data of viruses is a little more straight forward � viruses are simply not cut out to defend against the bleach onslaught! A group of scientists in New York studied the effects of very dilute concentrations of bleach on the respiratory syncytial virus (RSV). A tenfold dilution of bleach, which subsequently mixed with an equal volume of RSV-containing medium (so in fact a twentyfold dilution) eradicated all of the virus. A 100-fold dilution of bleach killed 100% of the virus half of the time, and decreased the number of live viral particles by greater than three logs in the other half of the tests. This was all after five minutes of treatment.</p> <p>So at least for viruses, you can probably dilute the bleach tenfold without worrying too much about decreased antimicrobial activity.</p> </blockquote> <p>Personally, I don't find any logic why bleach would be more effective diluted, the opposite makes more sense to me. Is there any explanation for this to be so? Or it's just a wrong idea?</p>
7
https://medicalsciences.stackexchange.com/questions/23868/are-betadine-mouthwashes-really-effective-against-covid-19
[ { "answer_id": 23870, "body": "<blockquote>\n <p>Are betadine mouthwashes really effective against COVID-19?</p>\n</blockquote>\n\n<p><em>In vitro</em> (test tubes/culture plates) studies do show that providone iodine does kill viruses <em>similar to</em> SARS-CoV-2 after sufficient exposure (just as bleach and ethyl/isopropyl alcohol do.)</p>\n\n<p>The answer <strong>in vivo</strong> (in humans or animals) is <strong>unknown</strong>. (<strong>N.B.:</strong> That's, <em>unknown</em>, as in, you should probably wait for more studies before (potentially serioulsy) harming yourself. Remember bleach, ethyl alcohol at or above 70% -140 proof - and certain industrial disinfectants do the same, which does not mean they should be used on human tissue. Most available PVP-I solutions available are toxic, even if diluted.)</p>\n\n<p>The first study listed found that <em>in vitro</em>,</p>\n\n<blockquote>\n <p>PVP-I gargle/mouthwash diluted 1:30 (equivalent to a concentration of 0.23% PVP-I) showed effective bactericidal activity against Klebsiella pneumoniae and Streptococcus pneumoniae and rapidly inactivated SARS-CoV, MERS-CoV, influenza virus A (H1N1) and rotavirus after 15 s of exposure.</p>\n</blockquote>\n\n<p>It is only assumed that because it is effective against SARS-CoV, it is also effective against SARS-CoV-2.</p>\n\n<p>It should be noted that <strong>not all providone-iodine solutions are created equally</strong>; the gargle preparation used in Japan cannot be obtained in the US and many other parts of the world, and the solutions used in the US are toxic at the same concentrations.</p>\n\n<p>The second paper listed also notes</p>\n\n<blockquote>\n <p>The utility and excellent safety profile of both topical nasal and oral solutions of PVP-I has long been recognized, especially at dilute concentrations (e.g. 0.001%). A detailed review of its virucidal activity against a wide range of common viruses, <strong>including SARS-CoV and MERS-CoV coronaviruses, is beyond the scope of this article</strong>.</p>\n</blockquote>\n\n<p>The next line is</p>\n\n<blockquote>\n <p>As a word of caution, in vitro studies using 10% and 5% PVP-I have demonstrated cilotoxicity on human respiratory cells. </p>\n</blockquote>\n\n<p>They go on to propose use of PVP-I <strong>on patients</strong> known to or suspected of having Covid-19 on whom high-risk procedures are being performed (head/neck surgery) and on healthcare providers pre- and post- exposure to these patients (Apply nasal and oral PVP-I prior to and after patient contact (with repeated contact, apply every 2–3 h, up to 4×/day) in healthcare providers that who <strong>lack adequate PPE (e.g. N95, PAPR).</strong></p>\n\n<p>They go on to conclude, in part,</p>\n\n<blockquote>\n <p>It is important to acknowledge that there is a potential risk in that prophylactic treatment of healthcare providers could increase susceptibility to SARS-CoV-2 infection by affecting mucociliary function or local immunity. </p>\n</blockquote>\n\n<p>One study seems stalled (cause unknown, recruitment issues?)</p>\n\n<p>while another tested (<em>in vitro</em>) a very specific kind of PVP-I (gel-forming) in very limited circumstances.</p>\n\n<p>The last paper is detailed and thorough (though please note the word <em>potential</em> in the title), and you can skip directly to the PVP-I section, where they state</p>\n\n<blockquote>\n <p>[the Japanese] mouthwash is not available in the United Kingdom, although may still be purchased in Germany and other countries. As a 1% solution, PVP-I is available in Hong Kong, Korea, Singapore, Malaysia, Philippines, and Taiwan. </p>\n</blockquote>\n\n<p><sub><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5986684/\" rel=\"nofollow noreferrer\">In Vitro Bactericidal and Virucidal Efficacy of Povidone-Iodine Gargle/Mouthwash Against Respiratory and Oral Tract Pathogens</a></sub><br>\n<sub><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7161480/\" rel=\"nofollow noreferrer\">Consideration of povidone-iodine as a public health intervention for COVID-19: Utilization as “Personal Protective Equipment” for frontline providers exposed in high-risk head and neck and skull base oncology care</a></sub><br>\n<sub><a href=\"https://clinicaltrials.gov/ct2/show/NCT04364802\" rel=\"nofollow noreferrer\">COVID-19: Povidone-Iodine Intranasal Prophylaxis in Front-line Healthcare Personnel and Inpatients (PIIPPI)</a></sub><br>\n<sub><a href=\"https://www.biorxiv.org/content/10.1101/2020.05.18.103184v1.abstract\" rel=\"nofollow noreferrer\">In-Vivo Toxicity Studies and In-Vitro Inactivation of SARS-CoV-2 by Povidone-iodine In-situ Gel Forming Formulations</a></sub><br>\n<sub><a href=\"https://academic.oup.com/function/article/1/1/zqaa002/5836301\" rel=\"nofollow noreferrer\">Potential Role of Oral Rinses Targeting the Viral Lipid Envelope in SARS-CoV-2 Infection</a></sub></p>\n\n<p><strong>Edited to add</strong>: <strong>In case there is confusion, I stated that the answer is <em>unknown</em>, and that most PVP-I solutions available are toxic in most countries. I am not an advocate of its use any more than 70% ethyl alcohol or bleach!</strong> </p>\n\n<p>I answered this question because it's important to engage with people reaching out for some answers in this pandemic, and because harmful advice is rife now (Even national leaders are making them, and they are surrounded by experts.) And to show that their concerns weren't unshared by some physicians. And that, like Barry Marshall's discovery, sometimes it's the most \"ridiculous\", \"preposterous\", and \"idiotic\" things that turn out to be true in medicine. But Barry Marshall paid a high price to prove his theory, both physically and emotionally, though winning the Nobel Prize was a very nice apology and recognition of the millions upon millions of people he saved from the barbaric approach to chronic ulcer treatment and stomach cancers before his discovery.</p>\n", "score": 7 } ]
23,868
CC BY-SA 4.0
Are betadine mouthwashes really effective against COVID-19?
[ "covid-19", "prevention", "virus", "mouthwash", "antiseptics" ]
<p>Recently news have come up that betadine/povidone-iodine mouthwashes should be used for prevention of COVID-19.</p> <p>Betadine is an antiseptic. We use it in our clinic to clean a wound or after minor surgeries eg. extraction.</p> <p>So are betadine mouthwashes effective against COVID-19? If yes, then how?</p> <p><a href="https://m.timesofindia.com/city/vijayawada/can-the-humble-betadine-help-fight-covid-19/amp_articleshow/75562922.cms" rel="nofollow noreferrer">Reference</a></p>
7
https://medicalsciences.stackexchange.com/questions/24757/is-water-an-essential-ingredient-of-alcohol-based-hand-sanitizers
[ { "answer_id": 24758, "body": "<p>Higher concentrations of alcohol are <a href=\"https://biology.stackexchange.com/questions/21511/how-does-isopropyl-alcohol-disinfect-less-in-higher-concentration\">actually less effective</a> (that Q&amp;A is specific for isopropyl, but the same is true for ethanol, their mechanism of sterilization is the same), see also <a href=\"https://biology.stackexchange.com/a/39934/27148\">here</a>.</p>\n<p>Summarizing from those answers: higher concentrations of alcohol don't penetrate into cells as well.</p>\n<p><a href=\"https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html\" rel=\"noreferrer\">This page from the CDC</a> also discusses optimal alcohol concentrations for disinfection and gives some references.</p>\n", "score": 12 } ]
24,757
CC BY-SA 4.0
Is water an essential ingredient of alcohol based hand sanitizers?
[ "alcohol", "hand-sanitizers" ]
<p>The two <a href="https://www.who.int/gpsc/5may/Guide_to_Local_Production.pdf" rel="noreferrer">WHO formulations</a> (ethanol and IPA) make up the volume with distilled or boiled water. But is this water essential for the best efficacy of the cleanser or is it only to bulk it out?</p> <p>In other words is dilute alcohol (75 - 80%) a better hand sanitizer than 99% (with minor additions of H2O2 and glycerine)?</p>
7
https://medicalsciences.stackexchange.com/questions/25339/how-do-pharmaceutical-companies-deal-with-people-who-received-a-placebo
[ { "answer_id": 25343, "body": "<p>This actually has been the <a href=\"https://www.nature.com/articles/d41586-020-03219-y\" rel=\"noreferrer\">subject</a> of a recent debate/article in <em>Nature</em>. The answer is that the approach varies, depending on the perceived risk for the subjects... One method previously used is to create a 3rd arm for participants on the placebo that receive[d] the actual vaccine later.</p>\n<blockquote>\n<p>Once a vaccine is granted emergency approval, there is pressure on developers to offer the immunization to trial participants who received a placebo. But if too many people cross over to the vaccine group, the companies might not have enough data to establish long-term outcomes, such as safety, how long vaccine protection lasts and whether the jab prevents infection or just the disease.</p>\n<p>[...]</p>\n<p>On 10 November, Pfizer sent a letter to participants, seen by Nature, which states that the company is exploring ways to allow interested participants in the placebo group who meet eligibility criteria for emergency access to cross over into the trial’s vaccine arm. A spokesperson told Nature that the company would have “an ethical responsibility to inform all study participants about the availability of an Emergency Authorized Vaccine.”</p>\n<p>The Pfizer spokesperson says that the company will discuss with the FDA how it will gather data to comprehensively measure safety and efficacy if participants cross over. The company’s clinical-trial plan says it intends to monitor participants for two years after their final vaccine dose.</p>\n<p>[...]</p>\n<p>There are ways of managing such disruptions without jeopardizing the trial outcome, says Kathleen Neuzil, director of the Center for Vaccine Development and Global Health at the University of Maryland in Baltimore. She is also co-chair of the US National Institutes of Health’s COVID-19 Prevention Trials Network, which arranges clinical trials for companies including Pfizer and Moderna. Participants who initially received a placebo but crossed over to get the vaccine could be monitored as a separate group, and a comparison of the vaccine’s long-term efficacy and safety could be made between those groups, she says. Neuzil used a similar set-up to determine the length of protection offered by the first shingles vaccine.</p>\n<p>Before unblinding the trials, companies could also ask volunteers to remain in the study and receive the vaccination as soon as the trial is over, says Corey.</p>\n</blockquote>\n", "score": 5 } ]
25,339
How do pharmaceutical companies deal with people who received a placebo?
[ "covid-19", "vaccination", "placebo" ]
<p>I would like to know what happens to the people in the vaccine studies who received a placebo.</p> <p>Essentially they have not been vaccinated. However, in order for the study to stay blind so that long term effects can be observed, they cannot be told they received a placebo.</p> <p>How do the pharmaceutical companies deal with this issue?</p> <p>When do they inform the placebo people so that they can be vaccinated? Or do they let them think they have had the vaccine already so that they can study what happens?</p>
7
https://medicalsciences.stackexchange.com/questions/25380/how-do-mrna-vaccines-work-and-what-are-their-advantages-over-traditional-vaccine
[ { "answer_id": 25381, "body": "<p>Regarding the steps, I'll get to #1 a bit later. It's actually a bit subtle how mRNA vaccines work in re #2, i.e. actually making sure translation happens. It also makes sense to discuss this first; otherwise, there's not much point in delivering something that doesn't work. A popsci <a href=\"https://www.statnews.com/2020/11/10/the-story-of-mrna-how-a-once-dismissed-idea-became-a-leading-technology-in-the-covid-vaccine-race/\" rel=\"noreferrer\">explanation</a> &quot;from the helicopter&quot; is that one needs to use &quot;modified nucleosides&quot; to begin with:</p>\n<blockquote>\n<p>The stumbling block, as Karikó’s many grant rejections pointed out, was that injecting synthetic mRNA typically led to that vexing immune response; the body sensed a chemical intruder, and went to war. The solution, Karikó and Weissman discovered, was the biological equivalent of swapping out a tire.</p>\n<p>Every strand of mRNA is made up of four molecular building blocks called nucleosides. But in its altered, synthetic form, one of those building blocks, like a misaligned wheel on a car, was throwing everything off by signaling the immune system. So Karikó and Weissman simply subbed it out for a slightly tweaked version, creating a hybrid mRNA that could sneak its way into cells without alerting the body’s defenses.</p>\n<p>“That was a key discovery,” said Norbert Pardi, an assistant professor of medicine at Penn and frequent collaborator. “Karikó and Weissman figured out that if you incorporate modified nucleosides into mRNA, you can kill two birds with one stone.”</p>\n</blockquote>\n<p>And the more in-depth version of that, from <a href=\"https://www.nature.com/articles/nrd.2017.243.pdf\" rel=\"noreferrer\">a review</a></p>\n<blockquote>\n<p>Enzymatically synthesized mRNA preparations contain double-stranded RNA (dsRNA) contaminants as\naberrant products of the IVT reaction. As a mimic of\nviral genomes and replication intermediates, dsRNA is\na potent pathogen-associated molecular pattern (PAMP)\nthat is sensed by pattern recognition receptors in multiple cellular compartments [...]. Recognition of IVT\nmRNA contaminated with dsRNA results in robust\ntype I interferon production, which upregulates the\nexpression and activation of protein kinase R (PKR; also\nknown as EIF2AK2) and 2'-5'-oligoadenylate synthetase\n(OAS), leading to the inhibition of translation and the\ndegradation of cellular mRNA and ribosomal RNA respectively. Karikó and colleagues have demonstrated\nthat contaminating dsRNA can be efficiently removed\nfrom IVT mRNA by chromatographic methods such as\nreverse-phase fast protein liquid chromatography (FPLC)\nor high-performance liquid chromatography (HPLC).\nStrikingly, purification by FPLC has been shown to\nincrease protein production from IVT mRNA by up\nto 1,000-fold in primary human DCs. Thus, appropriate purification of IVT mRNA seems to be critical for\nmaximizing protein (immunogen) production in DCs\nand for avoiding unwanted innate immune activation.</p>\n<p><strong>Besides dsRNA contaminants, single-stranded mRNA\nmolecules are themselves a PAMP when delivered to\ncells exogenously.</strong> Single-stranded oligoribonucleotides\nand their degradative products are detected by the endosomal sensors Toll-like receptor 7 (TLR7) and TLR8, resulting in type I interferon production.\nCrucially, it was discovered that the incorporation of\nnaturally occurring chemically modified nucleosides,\nincluding but not limited to pseudouridine and\n1-methylpseudouridine, prevents activation of TLR7,\nTLR8 and other innate immune sensors, thus reducing type I interferon signalling. Nucleoside modification\nalso partially suppresses the recognition of dsRNA species. As a result, Karikó and others have shown that\nnucleoside-modified mRNA is translated more efficiently\nthan unmodified mRNA in vitro, particularly in primary\nDCs, and in vivo in mice. Notably, the highest level of\nprotein production in DCs was observed when mRNA\nwas both FPLC-purified and nucleoside-modified.</p>\n</blockquote>\n<p>In other words, the mRNA gets &quot;blown to bits&quot; by the immune system before much translation, unless you're &quot;really clever&quot; how you introduce it, i.e. sans dsRNA contaminants (that are alas actually quite easy to produce) and with nucleoside-modification pseudouridine / 1-methylpseudouridine. If you look at the wiki article for <a href=\"https://en.wikipedia.org/wiki/Pseudouridine\" rel=\"noreferrer\">pseudouridine</a>, you'll see that it's naturally occurring in RNA, but it is rare. (It's actually a good question whether it is this relative rarity in nature that (evolutionary) has made the immune system not PAMP-react strongly to the pseudouridine-modified mRNA so that it can &quot;sneak in&quot; and get translated, instead of being mostly destroyed before translation. Alternatively or additionally, there's also the fact that pseudouridine seems to act as a more potent version of uridine.)</p>\n<p>As far step #1 is <a href=\"https://www.frontiersin.org/articles/10.3389/fimmu.2018.01963/full\" rel=\"noreferrer\">concerned</a>, &quot;naked&quot; mRNA doesn't survive for long in the extracellular space because of the &quot;omnipresence of extracellular ribonucleases&quot;. On top of that, mRNA from extracellular space is not take up effectively by the cells due to its &quot;hydrophilicity and strong net negative charge&quot;. So some kind of wrapper/vehicle that basically emulates a virus' envelope is needed. Various techniques/envelopes have been tried, but to keep this simple (and relevant to Covid vaccines currently approved), it's the LNP (lipid nano-particle) method that <a href=\"https://www.nature.com/articles/nrd.2017.243.pdf\" rel=\"noreferrer\">has</a> been used most successfully:</p>\n<blockquote>\n<p>Lipid nanoparticles (LNPs) have\nbecome one of the most appealing and commonly used\nmRNA delivery tools. LNPs often consist of four components:\nan ionizable cationic lipid, which promotes\nself-assembly into virus-sized (~100 nm) particles and\nallows endosomal release of mRNA to the cytoplasm;\nlipid-linked polyethylene glycol (PEG), which increases\nthe half-life of formulations; cholesterol, a stabilizing\nagent; and naturally occurring phospholipids, which\nsupport lipid bilayer structure. Numerous studies\nhave demonstrated efficient in vivo siRNA delivery\nby LNPs [...], but it has only recently\nbeen shown that LNPs are potent tools for in vivo delivery\nof self-amplifying RNA and conventional, non-replicating\nmRNA. Systemically delivered mRNA–LNP\ncomplexes mainly target the liver owing to binding of\napolipoprotein E and subsequent receptor-mediated\nuptake by hepatocytes, and intradermal, intramuscular\nand subcutaneous administration have been shown\nto produce prolonged protein expression at the site\nof the injection. The mechanisms of mRNA escape\ninto the cytoplasm are incompletely understood, not\nonly for artificial liposomes but also for naturally\noccurring exosomes. Further research into this area\nwill likely be of great benefit to the field of therapeutic\nRNA delivery.</p>\n</blockquote>\n<p>Wikipedia has <a href=\"https://en.wikipedia.org/wiki/Solid_lipid_nanoparticle\" rel=\"noreferrer\">an article</a> on some variety of these LNPs.</p>\n<p>Whether a RNA vaccine produces a more gradual immune response (than the traditional ones) is a good question (I don't know the answer off-hand), but if in &quot;inflammation&quot; we include allergic reactions, alas the sudden infusion of LNPs does <a href=\"https://www.sciencemag.org/news/2020/12/suspicions-grow-nanoparticles-pfizer-s-covid-19-vaccine-trigger-rare-allergic-reactions\" rel=\"noreferrer\">seem to cause some such allergic reactions</a>, although the link doesn't seem conclusive at the moment.</p>\n<blockquote>\n<p>Anaphylactic reactions can occur with any vaccine, but are usually extremely rare—about one per 1 million doses. As of 19 December, the United States had seen six cases of anaphylaxis among 272,001 people who received the COVID-19 vaccine, according to a recent presentation by Thomas Clark of the U.S. Centers for Disease Control and Prevention.</p>\n</blockquote>\n<p>Perhaps worth mentioning here that a naive (not using modified nucleosides) approach to RNA vaccines is basically &quot;pain for no (or little) gain&quot; as the response that comes with the immune-response destruction of mRNA is <a href=\"https://www.the-scientist.com/news-opinion/the-promise-of-mrna-vaccines-68202\" rel=\"noreferrer\">apparently</a> inflammatory in its symptoms:</p>\n<blockquote>\n<p>Ordinary mRNA produces only low levels of proteins, and the molecule degrades too quickly inside the body to make it suitable as a therapeutic. On top of that, RNA can trigger an immune response that’s independent of the response to the protein it encodes. “If you just inject foreign RNA into people or animals, you can induce a very serious inflammatory response,” Pardi [an mRNA vaccine specialist at the University of Pennsylvania] says. He adds that this is our bodies’ defense mechanism against viruses, which can use either DNA or RNA to store their genetic information.</p>\n</blockquote>\n<p>It's unclear whether the mRNA vaccines (of the clever, i.e. modified nucleosides kind) produce less inflammatory reactions than vaccines based on entirely different technologies for the same disease, but some experts have speculated that the high efficacy observed from the Covid-19 mRNA vaccines may actually be boosted by the &quot;usual&quot; inflammatory response to mRNA, as these are not completely absent even in modified nucleoside vaccines:</p>\n<blockquote>\n<p>[Margaret] Liu [the chairman of the board of the International Society for Vaccines] also hypothesizes that one explanation for the high levels of efficacy is that the vaccines might be triggering a nonspecific inflammatory response to the mRNA that could be heightening its specific immune response, given that the modified nucleoside technique reduced inflammation but hasn’t eliminated it completely. On the flip side, she adds, this may also explain the intense reactions such as aches and fevers reported in some recipients of the mRNA SARS-CoV-2 vaccines. (Others have suggested that the lipid nanoparticle is responsible for these severe, but transient, side effects reported in some trial participants.)</p>\n</blockquote>\n<p>According to a November <a href=\"https://www.sciencemag.org/news/2020/11/fever-aches-pfizer-moderna-jabs-aren-t-dangerous-may-be-intense-some\" rel=\"noreferrer\">story in Science</a> the Covid-19 mRNA vaccines produced more reactogencity (which includes inflammation) than typically expected in vaccines in general:</p>\n<blockquote>\n<p>Fewer than 2% of recipients of the Pfizer and Moderna vaccines developed severe fevers of 39°C to 40°C. But if the companies win regulatory approvals, they’re aiming to supply vaccine to 35 million people globally by the end of December. If 2% experienced severe fever, that would be 700,000 people.</p>\n<p>Other transient side effects would likely affect even more people. The independent board that conducted the interim analysis of Moderna’s huge trial found that severe side effects included fatigue in 9.7% of participants, muscle pain in 8.9%, joint pain in 5.2%, and headache in 4.5%. For the Pfizer/BioNTech vaccine, the numbers were lower: Severe side effects included fatigue (3.8%) and headache (2%).</p>\n<p>That’s a higher rate of severe reactions than people may be accustomed to. <strong>“This is higher reactogenicity than is ordinarily seen with most flu vaccines, even the high-dose ones,”</strong> says Arnold Monto, an epidemiologist at the University of Michigan School of Public Health.</p>\n</blockquote>\n<p>More up-to-date numbers on reactogenicity were actually the subject of <a href=\"https://medicalsciences.stackexchange.com/questions/25368/details-on-health-impact-events-on-v-safe-active-surveillance-for-covid-19-vac\">another question</a> here. (Apparently there were around 1% in a larger sample, i.e. around 3,000 cases in the 272,000 sample that was the topic of a recent CDC report.)</p>\n<p>And contra to Liu, Weissman says it's the LNPs that cause the local reactions, not the mRNA in its modified form:</p>\n<blockquote>\n<p>“We suspect the lipid nanoparticle causes the reactogenicity, because lipid nanoparticles without mRNA in them do the same thing in animals,” [...] “We see production, in the muscle, of inflammatory mediators that cause pain, [redness], swelling, fever, flulike symptoms, etc.”</p>\n</blockquote>\n<hr />\n<p>Briefly, as far as advantages of mRNA vaccines (despite the tech challenges, only resolved fairly recently), these come from the disadvantages of other vaccine techs. <a href=\"https://www.frontiersin.org/articles/10.3389/fimmu.2020.579250/full\" rel=\"noreferrer\">For example</a>, attenuated vaccines have more safety risks, adenovirus-platform vaccines present some risk of non-response due to anti-bodies to the vector etc. Basically mRNA vaccines produce response to a &quot;minimal target&quot; (also because the wrapper is synthetic &quot;nanotech&quot;.) Although many publications (from mRNA field) only speak of this as an advantage, clearly getting the target wrong in terms of the relevant proteins can be a problem, but presumably one that is fast and easy to identify.</p>\n<p>There is one (theoretical at least) immunological advantage to gene-based vaccines, the <strong><a href=\"https://jamanetwork.com/journals/jama/fullarticle/2770485\" rel=\"noreferrer\">recruitment</a> of the MHC-I pathway</strong>:</p>\n<blockquote>\n<p>genetic approaches have a potential immunological advantage. In addition to eliciting antibodies and CD4+ helper T cells, they recruit CD8+ cytotoxic T cells, also known as killer T cells, through the major histocompatibility class I pathway.</p>\n<p>According to Otto Yang, MD, an infectious disease researcher and clinician at the University of California, Los Angeles, David Geffen School of Medicine, the body’s cells only display viral proteins on their surface through this pathway if those cells themselves have produced the proteins. “If you just inject a protein or inject a dead virus, it doesn’t get into that pathway and doesn't get displayed that way, and so the T cells don’t get stimulated,” he said.</p>\n</blockquote>\n<p>And to sorta put it all in a one picture, the ACS <a href=\"https://www.cas.org/blog/covid-mrna-vaccine\" rel=\"noreferrer\">has</a> this probably most informative &quot;all in one&quot; pictures of how mRNA vaccines work, both before and after protein release, although the diagram eschews subtleties relating to step #2 (i.e. why modified nucleosides are needed):</p>\n<p><a href=\"https://i.stack.imgur.com/ShgvM.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/ShgvM.jpg\" alt=\"enter image description here\" /></a></p>\n<p>As far as the final quote in your question, that has more to do with how mRNA are produced (at scale), a discussion which is often eschewed in medical sources or dealt with in one sentence like &quot;fully synthetic manufacturing process that allows production of different vaccines using the same established production process and facility&quot;. Perhaps Chemistry SE would be a better place to ask for details on the latter, i.e. how mRNA vaccines are <em>produced</em> and why that is an industrial advantage. (I'm not saying it's off-topic here, just that questions on the manufacturing process of medications are practically non-existent here on Med SE, especially on the industrial angle.)</p>\n<p>On the <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5518734/\" rel=\"noreferrer\">level of generalities</a>, and mostly with respect to (difficulties of) vaccine manufacture by non-synthetic techniques:</p>\n<blockquote>\n<p>Vaccine manufacture is one of the most challenging industries. Even the most basic manufacturing steps necessary to produce vaccines in a manner that is safe, effective, and consistent over the life cycle of a vaccine are difficult to execute. Outcomes can vary widely due to the nearly infinite combinations of biological variability in basic starting materials, the microorganism itself, the environmental condition of the microbial culture, the knowledge and experience of the manufacturing technician, and the steps involved in the purification processes. To add to the complexity, the methods used to analyze the biological processes and antigens resulting from vaccine production often have high inherent variability. Failure to manage these risks can result in costly product recalls, and suspensions and penalties may be assessed if a manufacturer fails to fulfil supply agreements. In addition, lack of supply can disrupt routine immunization programs and negatively impact national public health outcomes.</p>\n<p>Regulatory authorities license not only a specific biological entity, but also the processes by which that entity is produced, tested, and released for use. Subtle changes in the production process may alter the final product and change its purity, safety, or efficacy. Further, the in vitro analytics required to release the product may not detect a change in process and a clinical trial may be needed to validate a new process and to maintain licensure of a product. <strong>This compounded risk of biological and physical variability makes vaccine manufacturing more challenging than typical small molecule pharmaceuticals and is a primary root cause of the high proportion of vaccine manufacturing failures</strong> and supply shortages. This is also the main reason why the number of vaccine manufacturers that succeed and thrive remains low despite unmet demand for many vaccines globally. Moreover, individual vaccine prices do not always decline, even after the patents expire, in contrast to pharmaceutical products. In fact, many vaccine patents protect the manufacturing process rather than the antigen that is produced by the process, which is not always the analogous case for small molecule pharmaceutical products. These process patents may present a more significant barrier to entry than the patent on the vaccine composition itself.</p>\n<p>Significant changes in the manufacturing process, such as new facilities, manufacturing equipment or changes in raw materials, will typically trigger new regulatory requirements, including clinical trials. These requirements will confirm that the vaccine is still effective and comparable to the product produced by the original vaccine process and studied in the original clinical studies. [...] <strong>Manufacturers are challenged to balance the competing goals of speed to market and process optimization; getting to market earlier increases revenue in the short term, but locking in a further optimized process may generate cost savings over the entire vaccine life-cycle.</strong></p>\n<p>There are many production platforms in use today and they vary widely [...] At one end [of production complexity] is live attenuated oral polio vaccine with significantly lower Cost of Goods Sold (COGS) while at the other end is the highly complex pneumococcal conjugate vaccine. While there may be common equipment across platforms such as bio reactors, filtration and chromatography equipment, filling and lyophilization equipment, the sequence of operations and the specific cycles for each product vary. In most cases, each product (or group of products within a product family) has its own dedicated facility and production team. This dedicated labor and equipment allows for flexibility to address unpredictable demand, but tends to increase costs. [...]</p>\n<p>Facilities can cost 50–500 M USD per antigen based on the high complexity of design, automation, segregation, utilities, and contamination controls, and as much as 700 M USD for multiple vaccines. [...] The US Department of Defense estimated the 25-year life-cycle cost of a 3-product facility to be 1.56 billion USD and that 7 years are needed to design, build, validate, and commence commercial manufacturing.</p>\n</blockquote>\n", "score": 5 } ]
25,380
CC BY-SA 4.0
How do mRNA vaccines work and what are their advantages over traditional vaccines?
[ "covid-19", "medications", "virus", "vaccination" ]
<p><strong>How do mRNA vaccines work?</strong></p> <p>To my intuitive understanding, for an mRNA vaccine to work, the mRNAs injected into the patient need to first enter a cell and get translated into proteins. Those proteins must then somehow exit the cell so that they can be seen by T cells. An mRNA vaccine hence appears considerably more complex than a traditional/protein vaccine.</p> <p>I envision these three steps as critical</p> <ol> <li>mRNAs get in cells</li> <li>mRNAs get translated</li> <li>proteins exit cells</li> </ol> <p>Am I right to think that such vaccine must go through these steps (or is there some other way around)? I failed to find anywhere explanations about these three steps? Could you give some explanations what exactly we inject to ensure these three steps will happen?</p> <p><strong>What are the advantages of mRNA vaccines over traditional vaccines?</strong></p> <p>I was thinking of potential advantage of such a complex vaccine and thought that maybe it has the advantage of inputting proteins into the bloodstream at a rate (rate that decreases over time with the half-life of the mRNA) while a traditional/protein vaccine makes a single large input of protein into the bloodstream. I am thinking, that might reduce risks of strong inflammation caused by the vaccine. Would it be true?</p> <p>I read from <a href="https://en.wikipedia.org/wiki/RNA_vaccine#Advantages" rel="noreferrer">Wikipedia &gt; RNAVaccine#advantages</a></p> <blockquote> <p>RNA vaccines can be produced faster, more cheaply, and in a more standardized fashion (with fewer error rates in production), which can improve responsiveness to serious outbreaks.</p> </blockquote> <p>Can you please explain why this is true?</p>
7
https://medicalsciences.stackexchange.com/questions/25442/bnt162b2-mrna-covid-19-vaccine-efficacy-after-1st-dose-explain-the-statistics
[ { "answer_id": 25443, "body": "<p>The paper itself describes how this is calculated (see the Methods section), but also see this Q&amp;A at Biology.SE talking more broadly about how efficacy has been defined in these vaccine trials:</p>\n<p><a href=\"https://biology.stackexchange.com/q/96941/27148\">https://biology.stackexchange.com/q/96941/27148</a></p>\n<p>They define efficacy as the fraction of infected in the vaccine compared to placebo categories, normalized for observation time (the integral of time by number observed). Quoting from the paper you linked:</p>\n<blockquote>\n<p>Vaccine efficacy was estimated by 100×(1−IRR), where IRR is the calculated ratio of confirmed cases of Covid-19 illness per 1000 person-years of follow-up in the active vaccine group to the corresponding illness rate in the placebo group</p>\n</blockquote>\n<p>giving the equations</p>\n<p>IRR = (VaccineInfections/VaccinePersonYears/1000)/(PlaceboInfections/PlaceboPersonYears/1000)</p>\n<p>VE = 100 * (1 - IRR)</p>\n<p>If VaccinePersonYears and PlaceboPersonYears are equal, then IRR reduces to:</p>\n<p>IRR = VaccineInfections/PlaceboInfections= 39/82 = 0.48</p>\n<p>100 * (1-0.48) = 52% effective</p>\n<p>So yes, this is algebraically equivalent to the equation you give, but it's originally calculated based on the actual data, not the simplified formula. It's just likely that VaccinePersonYears and PlaceboPersonYears are sufficiently similar (remember, they're giving the vaccine and placebo 50:50 to people in the same time frame), and it's a large study with thousands of participants so drop outs and such are likely to even out statistically and reduce to the simplified form you give.</p>\n", "score": 10 }, { "answer_id": 25444, "body": "<p>The formula used for vaccine efficacy is as follows:</p>\n<pre><code>VE = (ARU - ARV) / ARU\n\n(VE: vaccine efficacy, ARU: attack rate in unvaccinated participants, ARV: attack rate in vaccinated participants)\n</code></pre>\n<p>This is equivalent to:</p>\n<pre><code>VE = 1 - RR\n\n(RR: Relative risk)\n</code></pre>\n<p>The attack rate is simply the number of new cases divided by the total group size.</p>\n<pre><code>ARV = 39 / 21,314 = 0.00182978\n\nARU = 82 / 21,258 = 0.00385737\n\nVE = 0.5256 which is approximately 52%\n</code></pre>\n<p>These numbers are from figure three in the linked paper, showing the number of cases in each group between the first dose and the second dose (i.e. ignoring the effect of a second dose). The vaccine efficacy rose to approximately 95% by seven days after the second dose.</p>\n<p>Your calculation produced a similar result due to the very similar group sizes (21,314 and 21,258).</p>\n<p>Importantly, the authors note:</p>\n<blockquote>\n<p>The study was not designed to assess the efficacy of a single-dose regimen.</p>\n</blockquote>\n<p>This places caveats on the conclusions that can be drawn from this study with regard to a single-dose regimen of this vaccine.</p>\n<hr />\n<p>The Wikipedia page on <a href=\"https://en.wikipedia.org/wiki/Vaccine_efficacy\" rel=\"noreferrer\">vaccine efficacy</a> provides a good summary of the measure and the associated caveats.</p>\n", "score": 6 } ]
25,442
CC BY-SA 4.0
BNT162b2 mRNA Covid-19 Vaccine efficacy after 1st dose - explain the statistics
[ "covid-19", "vaccination", "statistics", "clinical-study" ]
<p>Pfizer's paper (<a href="https://www.nejm.org/doi/full/10.1056/NEJMoa2034577" rel="noreferrer">Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine</a>) published recently states the following in the Efficacy subsection of the Results section:</p> <blockquote> <p>Between the first dose and the second dose, 39 cases in the BNT162b2 group and 82 cases in the placebo group were observed, resulting in a vaccine efficacy of 52% (95% CI, 29.5 to 68.4) during this interval and indicating early protection by the vaccine, starting as soon as 12 days after the first dose.</p> </blockquote> <p>Can anyone explain in simple terms the calculation of 52%? I am guessing that this number was obtained from: <a href="https://i.stack.imgur.com/zbFa2.png" rel="noreferrer"><img src="https://i.stack.imgur.com/zbFa2.png" alt="formula" /></a></p> <p>But why is that the calculation? Does it depend on the fact that the vaccine and placebo groups were in equal numbers, such that by observing 82 COVID-19 cases in the placebo group, we match 82 subjects in the vaccine group, and since only 39 confirmed cases were observed in the vaccine group, the authors conclude that the &quot;complementary (to 82)&quot; 43 subjects did not become sick, and thus the vaccine is efficient in 52% of the subjects?</p>
7
https://medicalsciences.stackexchange.com/questions/25759/covid-19-vaccination-second-doses-why-two-doses-and-why-the-specified-interval
[ { "answer_id": 26022, "body": "<p>From <a href=\"https://jamanetwork.com/journals/jama/fullarticle/2776229\" rel=\"nofollow noreferrer\">an article in JAMA</a></p>\n<blockquote>\n<p>When the [Pfizer and Moderna] vaccines were first tested, a relatively weak immune reaction was found within a few weeks after people received the first dose of vaccine, followed by a strong reaction when a second dose was given.</p>\n</blockquote>\n<p>Multiple doses are not uncommon in vaccinations. <a href=\"https://www.cdc.gov/vaccines/vpd/shingles/public/shingrix/index.html\" rel=\"nofollow noreferrer\">Shingrix</a>, a shingles vaccination is also two dose, as are <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4147727/#R12\" rel=\"nofollow noreferrer\">HPV vaccines</a>.</p>\n<p><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4147727/\" rel=\"nofollow noreferrer\">Additional Information</a>:</p>\n<blockquote>\n<p>Successful immunization depends upon immune memory and vaccine immunization schedules (i.e. the number of doses and the time elapsed between doses) that are designed to generate optimal immune memory. [...] Memory is evoked as a consequence of initial or primary immunization, which elicits a primary immune response. This “priming” enables the immunized individual to mount a more potent and rapid response to subsequent challenges with the same antigen. The response to each subsequent immunization (secondary, tertiary, etc.) thus increases in intensity [of immune response].</p>\n</blockquote>\n", "score": 2 } ]
25,759
CC BY-SA 4.0
COVID-19 vaccination second doses: why two doses and why the specified interval?
[ "covid-19", "vaccination" ]
<p>Certain COVID-19 vaccines such as the Pfizer BioNTech and Moderna are specified to be administered in two doses separated by a 21 and 28 day interval, respectively. My questions are:</p> <ol> <li>Why administered in two doses versus (perhaps) one larger dose? Some vaccines are &quot;single dose&quot; but some are not. What is going on biologically/biochemically that requires or favors a two-dose regimen and why does this not apply in the case of single-dose vaccines? Does it relate to the &quot;platform&quot; (mRNA vs adenovirus, etc.)?</li> <li>Why the specified interval? How was it determined that 21 or 28 days would be the optimum interval between doses? What is going on in the body at or about 21 or 28 days that makes it optimal to administer a second dose at that time but not sooner or later?</li> <li>Why is there a difference in interval between the Pfizer at 21 days and Moderna at 28 days?</li> </ol>
7
https://medicalsciences.stackexchange.com/questions/25907/if-covid-19-isnt-spread-through-even-food-why-is-it-recommended-to-disinfect-c
[ { "answer_id": 30973, "body": "<p>It is recommended to do so, because if you sneeze, cough or get any other germs on your hands, it would touch any object - book, pencil, fabric, metal - really, anything. Even if you don't have the symptoms, there is a possibility of you being sick with any cold, flue or, even, covid.</p>\n<p>Keep in mind, that other people would be touching those objects as well, at some point at the least. These germs and bacteria could spread to other people (they will touch their face or anywhere near it).</p>\n<p>Sanitizer or any other one of those chemicals 'cleanses' the objects of that bacteria through a specific amount of time (it won't disinfect it the very second you apply it). This helps keep people from getting sick.</p>\n<p>Hope this helped!</p>\n", "score": 1 } ]
25,907
CC BY-SA 4.0
If COVID-19 isn&#39;t spread through even food, why is it recommended to disinfect common objects?
[ "covid-19", "disease-transmission", "disinfection" ]
<p>Currently, researchers say that there is <strong>no evidence of COVID-19 spreading through food</strong>:</p> <blockquote> <ul> <li>&quot;The risk of getting COVID-19 from food you cook yourself or from handling and consuming food from restaurants and takeout or drive-thru meals is thought to be very low. Currently, there is no evidence that food is associated with spreading the virus that causes COVID-19.</li> <li>&quot;The risk of infection by the virus from food products, food packaging, or bags is thought to be very low. Currently, no cases of COVID-19 have been identified where infection was thought to have occurred by touching food, food packaging, or shopping bags.&quot; (<a href="https://www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/food-and-COVID-19.html" rel="nofollow noreferrer">source: CDC, updated Dec 31, 2020</a>)</li> </ul> </blockquote> <p>Since I would say eating is one of the more &quot;high transmission&quot; ways of interacting with an infected object, to me this implies that COVID-19 transmission <em>is very low or nonexistent through objects in general.</em> This seems to also be supported by the CDC listing inedible food-related items in the above source, such as packaging or shopping bags.</p> <p>In spite of this, there are <strong>recommendations for extensive cleaning of shared objects</strong>:</p> <blockquote> <p>&quot;[If caring for someone sick at home,] Clean and disinfect “high-touch” surfaces and items every day: This includes tables, doorknobs, light switches, handles, desks, toilets, faucets, sinks, and electronics.&quot; (<a href="https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/care-for-someone.html#handwashing" rel="nofollow noreferrer">source: CDC, updated Feb 11, 2021</a>)</p> </blockquote> <blockquote> <p>&quot;Surfaces and objects in public places, such as shopping carts, point of sale keypads, pens, counters, vending machines, and ATMs should be cleaned and disinfected before each use or as much as possible. Other high touch surfaces include: Tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, sinks.&quot; (<a href="https://www.cdc.gov/coronavirus/2019-ncov/community/disinfecting-building-facility.html" rel="nofollow noreferrer">source: CDC, updated Jan 5, 2021</a>)</p> </blockquote> <p>There are some excerpts that discuss why disinfection is theoretically useful, but since there is no evidence of spread through food, <strong>I'm inclined to think this is just precautious assumptions</strong> <em>(note that the language is often &quot;it is possible...&quot;, not &quot;there is evidence of...&quot;)</em>:</p> <blockquote> <p>&quot;COVID-19 spreads less commonly through contact with contaminated surfaces[.] Respiratory droplets can also land on surfaces and objects. It is possible that a person could get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or eyes. Spread from touching surfaces is not thought to be a common way that COVID-19 spreads&quot; (<a href="https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-covid-spreads.html" rel="nofollow noreferrer">source: CDC, updated Oct 28, 2020</a>)</p> </blockquote> <p><strong>Given the above, is disinfecting shared objects actually important for limiting the spread of COVID-19, or are those recommendations based in unsubstantiated claims about COVID-19 transmission?</strong></p>
7
https://medicalsciences.stackexchange.com/questions/28985/can-autoantibodies-found-in-the-father-affect-the-embryo-and-how
[ { "answer_id": 28987, "body": "<p>I think you're right to be stumped.</p>\n<p>The text you're referring to discusses Fig. 3C in the review; they note it's preliminary data but also seem to use strange/wrong descriptions, e.g. in the Fig 3 caption: &quot;The presence of maternal FRα antibodies or presence of antibodies in both parents will negatively affect the treatment outcome.&quot;</p>\n<p>I <em>think</em> someone just looked at Fig 3C (which lists patient, mother, father FRAb levels as +/-) and tried to come up with a result description without considering the underlying implications.</p>\n<p>Just quickly looking at that section of the review, the Fig 3 graphs don't seem very convincing to me, as the error bars indicate a lot of overlap between the groups and it's unclear how much blind equivalent treatment there was (at least some of these are 2 year long interventions!). Fig 3C in particular seems to subdivide 82 patients into 6 FRAb categories, leaving very few per category and thus unclear statistical power.</p>\n", "score": 4 } ]
28,985
CC BY-SA 4.0
Can autoantibodies found in the father affect the embryo, and how?
[ "autoimmune-disease", "antibodies", "autism", "folate", "cerebral-folate-deficiency" ]
<p>From &quot;<a href="https://www.mdpi.com/2075-4426/11/8/710/htm" rel="noreferrer">Folate Receptor Alpha Autoantibodies in Autism Spectrum Disorders: Diagnosis, Treatment and Prevention</a>&quot; (2021):</p> <blockquote> <p>Comparison of the Childhood Autism Rating Scale (CARS) after 2 years of treatment (folinic acid supplementation and correction of abnormal nutrient values) with the CARS at baseline showed better outcomes for children having negative or low FRα antibody titers of the blocking type, up to 0.44 pmol FRα blocked/mL serum, versus the group whose FRα antibody titers were above 0.44. The baseline CARS score increased as a function of the age at which treatment was initiated. The outcome became poorer for the older subgroup of treated autistic children (Figure 3B). This outcome may be further compounded by the presence of maternal and paternal autoantibodies and <strong>embryonic exposure to these</strong>. Preliminary data suggested that in the event of maternal or parental FRα autoantibodies, the child´s outcome after treatment was also less favorable (Figure 3C).</p> </blockquote> <p>This stumped me. How can paternal autoantibodies affect the embryo? Isn't this a typo? Maybe there is some indirect way of paternal antibodies affecting the unborn child? I googled but found nothing.</p>
7
https://medicalsciences.stackexchange.com/questions/30651/did-covid-vaccine-studies-use-an-active-placebo-with-side-effects
[ { "answer_id": 30681, "body": "<p>The AstraZeneca COVID-19 vaccine approved by <a href=\"https://www.ema.europa.eu/en/medicines/human/EPAR/vaxzevria-previously-covid-19-vaccine-astrazeneca\" rel=\"noreferrer\">EU</a> and <a href=\"https://www.gov.uk/government/publications/regulatory-approval-of-covid-19-vaccine-astrazeneca\" rel=\"noreferrer\">UK</a> regulatory authorities used a meningitis vaccine as the control in phase 2/3 trials.</p>\n<p>From the methods section of <a href=\"https://doi.org/10.1016/S0140-6736(20)32466-1\" rel=\"noreferrer\">their paper</a>:</p>\n<blockquote>\n<p>Participants were randomly assigned to receive either the ChAdOx1 nCoV-19 vaccine or the quadrivalent MenACWY protein-polysaccharide conjugate vaccine. MenACWY was used as a comparator vaccine rather than a saline placebo to maintain masking of participants who had local or systemic reactions.</p>\n</blockquote>\n<p>Confidence intervals for side effects overlapped between the treatment and control groups (see the appendix in the above linked paper), though the study wasn't powered to detect moderate differences. It seems these investigators may have met their goal of avoiding unmasking due to side effects.</p>\n<p>This doesn't guarantee that unmasking didn't occur for some other reason. I'd note that no masking assessment was reported, though it rarely is. It is possible to assess masking by, e.g., asking participants whether they think they received the treatment or control. Unmasking can occur for a variety of reasons, side effects are just one of them. For example, trials of interventions that are a bit more complex than a pill (e.g., injection, IV) often don't blind staff who administer the intervention and control, but keep the participants, investigators, and the people who collect the data blind. This comes with a risk of unmasking, but is balanced against the challenge (and likely failure) of making the intervention and treatment look exactly alike, push exactly alike, etc.</p>\n", "score": 6 }, { "answer_id": 30669, "body": "<h4>Of the three vaccine products that have been approved or had emergency use authorization in the United States, all used saline placebo in the clinical trial.</h4>\n<p>From the Pfizer <a href=\"https://doi.org/10.1056/NEJMoa2034577\" rel=\"nofollow noreferrer\">Polack et al paper</a>:</p>\n<blockquote>\n<p>With the use of an interactive Web-based system, participants in the trial were randomly assigned in a 1:1 ratio to receive 30 μg of BNT162b2 (0.3 ml volume per dose) or <strong>saline placebo</strong>.</p>\n</blockquote>\n<p>From the Moderna <a href=\"https://doi.org/10.1056/nejmoa2035389\" rel=\"nofollow noreferrer\">Baden et al paper</a>:</p>\n<blockquote>\n<p>Injections were given 28 days apart, in the same arm, in a volume of 0.5 ml containing 100 μg of mRNA-1273 or <strong>saline placebo</strong>.</p>\n</blockquote>\n<p>From the Johnson &amp; Johnson <a href=\"https://doi.org/10.1056/NEJMoa2101544\" rel=\"nofollow noreferrer\">Sadoff et al paper</a>:</p>\n<blockquote>\n<p>Participants were randomly assigned in a 1:1 ratio, with the use of randomly permuted blocks, to receive either Ad26.COV2.S or <strong>saline placebo</strong>.</p>\n</blockquote>\n<p>Thus, we should expect that a mild salt water solution would not elicit much of an immune response. This is a potential weakness of the trial design. Nonetheless, the results were sufficient to result in full approval of the Pfizer product.</p>\n", "score": 4 } ]
30,651
CC BY-SA 4.0
Did covid vaccine studies use an active placebo (with side effects)?
[ "covid-19", "vaccination", "clinical-study", "placebo" ]
<p>I know that the studies done by Pfizer, et al, used standard methods with a placebo control group. If you read about <a href="https://en.wikipedia.org/wiki/Blinded_experiment" rel="noreferrer">blinded experiments here</a>, it mentions:</p> <blockquote> <p>A common cause for unblinding is the presence of side effects (or effects) in the treatment group. In pharmacological trials, premature unblinding can be reduced with the use of an active placebo, which conceals treatment allocation by ensuring the presence of side effects in both groups.</p> </blockquote> <p>As we know, the covid vaccines have some side effects. Anecdotally, I know many people who reported feeling a bit sick for a day after getting one. So my question is, did this &quot;unblind&quot; the participants in the covid vaccine trials? Or did they use a placebo that caused some level of irritation, in order to better hide this?</p>
7
https://medicalsciences.stackexchange.com/questions/30949/why-should-males-use-contraception-for-longer-after-taking-molnupiravir-for-covi
[ { "answer_id": 30952, "body": "<p>The mechanism of action of molnupiravir is &quot;lethal mutagenesis&quot; (see <a href=\"https://www.nature.com/articles/s41594-021-00657-8\" rel=\"noreferrer\">Malone and Campbell, 2021</a>) - it interferes with the viral RNA polymerase by introducing copying errors severe enough that the resulting RNA cannot code anything functional.</p>\n<p>The mechanism is selective to viral RNA polymerase, but <a href=\"https://pubmed.ncbi.nlm.nih.gov/33961695/\" rel=\"noreferrer\">Zhou et al, 2021</a> have found DNA mutagenesis induced in cell culture:</p>\n<blockquote>\n<p><em>(active metabolite of molnupiravir)</em> also displays host mutational activity in an animal cell culture assay, consistent with RNA and DNA precursors sharing a common intermediate of a ribonucleoside diphosphate</p>\n</blockquote>\n<p>Three months is a rough approximation to the timeline of <a href=\"https://en.wikipedia.org/wiki/Spermatogenesis\" rel=\"noreferrer\">spermatogenesis</a>. DNA replication during <a href=\"https://en.wikipedia.org/wiki/Oogenesis\" rel=\"noreferrer\">oogenesis</a> occurs much earlier.</p>\n<p>Biologically, these guidelines are consistent with preventing presence of the drug during DNA replication in gametes, zygote, and embryo. Because DNA replication is occurring in sperm but not eggs within the immediate months before conception, there is a longer pre-conception window for males versus females.</p>\n<p>The FDA's discussion about these research findings is revealed in the <a href=\"https://www.fda.gov/media/155241/download\" rel=\"noreferrer\">Emergency Use Authorization for Molnupiravir</a>:</p>\n<blockquote>\n<p>Uncertainty about genotoxicity was cited as a cause for concern by\nCommittee members... A particular concern raised was the potential effect on male germ cells that could result in birth defects. As the <em>in vivo</em> mutagenicity assays performed to date use somatic cells ... and not germ cells (eggs and sperm), the ability for [molnupiravir] (MOV) to induce mutations in germ cells has not been directly assessed. Somatic cell assays may represent a worst-case, as male germ cells, while reproductively active in adults, appear to be relatively protected from mutagenic DNA damage, including having more efficient DNA repair mechanisms than do somatic cells (Olsen et al. 2001). However, the capacity for DNA repair appears to wane as spermatogonia\nmature to sperm (Marchetti and Wyrobek 2008) in a process that takes 74 days in humans.</p>\n<p>Repair mechanisms such as mismatch repair and homologous recombination that are active in the earliest phases of spermatogenesis give way to the more error-prone nonhomologous end joining process in spermatids (Garcia-Rodriguez et al. 2018). ... <strong>Male germ cell (sperm) maturation starts in early puberty and the sperm maturation process takes 74 days; a period covered by the use\nof contraception for 90 days in males of reproductive potential who are exposed to MOV</strong>. The carcinogenicity study and the testicular germ cell mutation assay will provide data regarding the risk to male patients, and their offspring, beyond 90 days.</p>\n</blockquote>\n<hr />\n<p>Malone, B., &amp; Campbell, E. A. (2021). Molnupiravir: Coding for catastrophe. Nature Structural &amp; Molecular Biology, 28(9), 706-708.</p>\n<p>Zhou, S., Hill, C. S., Sarkar, S., Tse, L. V., Woodburn, B. M., Schinazi, R. F., ... &amp; Swanstrom, R. (2021). β-d-N 4-hydroxycytidine inhibits SARS-CoV-2 through lethal mutagenesis but is also mutagenic to mammalian cells. The Journal of infectious diseases, 224(3), 415-419.</p>\n", "score": 11 } ]
30,949
CC BY-SA 4.0
Why should males use contraception for longer after taking molnupiravir for COVID?
[ "covid-19", "antivirals", "teratogenicity" ]
<p><strong>Molnupiravir</strong> (brand name Lagevrio) is a small-molecule antiviral prodrug active against SARS-Cov-2 and in one trial was found to reduce risk of hospitalization or death from COVID by 52% (Jayk Bernal <em>et al</em> 2022. PMID <a href="https://pubmed.ncbi.nlm.nih.gov/34914868/" rel="nofollow noreferrer">34914868</a>).</p> <p>According to the <a href="https://www.nytimes.com/explain/2022/03/21/well/covid-antiviral-pills" rel="nofollow noreferrer"><em>New York Times</em></a>:</p> <blockquote> <p>Molnupiravir cannot be used during pregnancy because of the potential harm to the fetus. For this reason, doctors may also recommend that sexually active men and women of childbearing age use contraception during treatment and for a period afterward (<strong>three months for men</strong> and four days for women).</p> </blockquote> <p>The <a href="https://www.fda.gov/media/155054/download" rel="nofollow noreferrer">package insert</a> confirms these recommendations and there is a <a href="https://en.wikipedia.org/wiki/Boxed_warning" rel="nofollow noreferrer">black box warning</a>:</p> <blockquote> <p>Based on findings from animal reproduction studies, LAGEVRIO may cause fetal harm when administered to pregnant individuals.</p> </blockquote> <p>It also mentions:</p> <blockquote> <p>While the risk is regarded as low, nonclinical studies to fully assess the potential for LAGEVRIO to affect offspring of treated males have not been completed. Advise sexually active individuals with partners of childbearing potential to use a reliable method of contraception correctly and consistently during treatment and for at least 3 months after the last dose of LAGEVRIO.The risk beyond three months after the last dose of LAGEVRIO is unknown. Studies to understand the risk beyond three months are ongoing.</p> </blockquote> <p>As <a href="https://www.forbes.com/sites/williamhaseltine/2021/11/02/harming-those-who-receive-it-the-dangers-of-molnupiravir-part-2/" rel="nofollow noreferrer">an article from Forbes</a> notes:</p> <blockquote> <p>Reporters have asked the manufacturers about potential mutagenic effects, which Merck has answered by saying that, “the drug will be safe if used as intended and at the concentrations where we have looked and in the concentrations which we are achieving in patients.”</p> </blockquote> <h4>What is the hypothesized mechanism underlying the recommendation that males use contraception for three <em>months</em> after taking molnupiravir while females should only use contraception for four <em>days</em>?</h4>
7
https://medicalsciences.stackexchange.com/questions/31204/what-kind-of-inflammation-is-caused-by-diabetes
[ { "answer_id": 31250, "body": "<p>As @anongoodnurse pointed out, a pre-inflammatory state is present before T2D develops. Most of the patients of Type 2 Diabetes mellitus are obese. They may have dyslipidemia wherein sub-acute chronic inflammation is common.</p>\n<p>The most common and well studied pathway is Inflammasome/IL-1β signalling. Cells have cytosolic NOD-like receptors that recognize diverse molecules that are liberated or altered. They signal via a multiprotein complex called the <em>Inflammasome</em>. Excess free fatty acids within macrophages and β-cells can lead to Inflammasome activation which activates an enzyme (caspase-1) which cleaves precursor form of IL-1β to it's active form. IL-1β mediates the secretion of other pro-inflammatory cytokines from macrophages, islet cells and other cells.</p>\n<p>This is just one mechanism through which inflammation can occur. Others include accumulation of DAG, phospholipids, ceramides, etc. which are toxic lipid metabolites that can attenuate signalling through the insulin receptor and activate inflammatory pathway in the islets. Liver steatosis can also lead to inflammation and hepatocyte injury which can impair glucose homeostasis.</p>\n<p><strong>References</strong>:</p>\n<ol>\n<li><p>Robbins and Cotran Pathologic Basis of\nDisease, 10e</p>\n</li>\n<li><p>Tsalamandris, S., Antonopoulos, A. S.,\nOikonomou, E., Papamikroulis, G. A.,\nVogiatzi, G., Papaioannou, S.,\nDeftereos, S., &amp; Tousoulis, D. (2019).\nThe Role of Inflammation in Diabetes:\nCurrent Concepts and Future\nPerspectives. European cardiology,\n14(1), 50–59.\n<a href=\"https://doi.org/10.15420/ecr.2018.33.1\" rel=\"nofollow noreferrer\">https://doi.org/10.15420/ecr.2018.33.1</a></p>\n</li>\n<li><p>Remmerie, A., &amp; Scott, C. L. (2018).\nMacrophages and lipid metabolism.\nCellular immunology, 330, 27–42.\n<a href=\"https://doi.org/10.1016/j.cellimm.2018.01.020\" rel=\"nofollow noreferrer\">https://doi.org/10.1016/j.cellimm.2018.01.020</a></p>\n</li>\n</ol>\n", "score": 5 } ]
31,204
What kind of inflammation is caused by diabetes?
[ "diabetes", "inflammation", "pathophysiology", "covid" ]
<p>Quote from <a href="https://www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=https://coronavirus.baltimorecity.gov/sites/default/files/Diabetes%2520COVID%2520final.pdf&amp;ved=2ahUKEwjV4eLQwqr0AhVKkMMKHX5UBYcQFnoECA8QAQ&amp;usg=AOvVaw3VSr4cTtnim_s7-9zoEGZk" rel="nofollow noreferrer">the notice for diabetics about COVID</a>:</p> <blockquote> <p>Diabetes causes inflammation in the body and you have a harder time fighting off an infection like the virus that causes COVID-19</p> </blockquote> <p>What does it mean &quot;diabetes causes inflammation&quot;? I know there are a lot of short-term problems like hyperglycemia, hypoglycemia and long-term complications diabetes may cause, like neuropathy, retinopathy, and a lot more over time, but it's first time I hear about inflammation caused by diabetes. Like what it is exactly, does it mean that all diabetics have some kind of constant inflammation in their body and that is aggravated when they get sick? Or they refer to one of those complications/problems as inflammation (which I think is not correct).</p>
7
https://medicalsciences.stackexchange.com/questions/31856/can-n95-face-masks-filter-out-benzopyrene-polycyclic-aromatic-hydrocarbons-or-f
[ { "answer_id": 31859, "body": "<p>No.</p>\n<p>No, no, no.</p>\n<p>Covid face masks help prevent contagious disease. They are not meant for anything else. Period. End of public health announcement.</p>\n<p>To be clear, N95 facemasks are particulate respirators. They do not protect against organic vapors, carcinogenic or otherwise.</p>\n<p>The posed question becomes complex with the inclusion of extensive background material, references, and opinions. Of note, the research excludes mask specifications. The discussion conflates the foundational concepts of smoke and vapor. The conclusion quotes the CDC, summarizes the authoritative and comprehensive guidance of the New York State Department of Health, and then goes on to remark &quot;but that was not very helpful.&quot;</p>\n<p>It is hoped that this reply will dispel many of the myths making the public think that these new face masks will now keep them safe from anything and everything dangerous in the air. It's just not true, and it's dangerous when folks believe or imply otherwise.</p>\n<p>Although N95 masks are required by OSHA for people who work in specific smoke environments and have helped a lot of regular folks who live in wildfire zones, they CAN NOT filter commonly co-present carcinogenic compounds in the kitchen or anywhere else.</p>\n<p>As requested in the question, the above remarks are provided to clarify by promoting trust in the American institutions empowered to provide reliable, factual answers to public health questions such as yours.</p>\n", "score": 18 }, { "answer_id": 31861, "body": "<p><strong>TL;DR</strong> - The specific answer is &quot;NO, N95 masks cannot reliably protect one from the questioned chemicals/compounds&quot;. But there's so much more to consider...</p>\n<p>This supplemental answer is more broad than the specific, misguided focus on N95 masks. That's not meant to insult, it's meant as recognition of the complexity of the world of safety controls, of which N95 masks are a small part. Even seasoned safety officers, like myself, find that protecting others from myriad dangers is an arduous task requiring years of study, intense application analyses, and quite a lot of human psychology application. Without a good understanding of safety principles, an internet search and a few articles will likely confuse and lead one astray.</p>\n<p><strong>N95 Masks</strong></p>\n<p>At the very base of the question, any protective mask must be appropriate to the application. &quot;N95 mask&quot; is actually a broad category; there are numerous types of N95 masks created for their specific use. Assuming the question is referencing the type of N95 masks made popular by the COVID-19 pandemic and CDC response, these are masks specific to medical/biological protection applications; they should not be assumed effective in any other application, be it chemical vapors, smoke, radiologics, even other novel biologics for which they have not been specifically tested and approved. In short, if the mask is not made, tested, and approved for the application, then one really has no idea whether it will work.</p>\n<p>Even if one has determined a correct mask/respirator type, one still needs to assure that the manufacturer and seller are legitimate. The COVID-19 pandemic and resulting supply glut brought numerous counterfeit masks to the supply chain. <a href=\"https://www.cdc.gov/niosh/npptl/usernotices/counterfeitResp.html\" rel=\"noreferrer\">https://www.cdc.gov/niosh/npptl/usernotices/counterfeitResp.html</a>.</p>\n<p><strong>Research</strong></p>\n<p>Another issue with gaining knowledge from internet sources is a misunderstanding of the research process. Research articles may be published, later refuted, found to be flawed with additional research, found to be biased leading to inaccurate conclusions, or may be built upon by additional research and generally accepted as accurate. This is what professional organizations such as CDC, NIOSH, and many others do - they understand the research and apply it appropriately for the world. This process takes years, and is not perfect (because humans are not perfect).</p>\n<p>The given research articles generally <em>suggest</em> that frying foods is likely a threat to health. But this needs to be supported by additional research to say how much threat exists, for whom, in what amounts, for what exposure time, and more. Not to mention the relative harm of actually eating the foods discussed. Research additionally needs to support our understanding of appropriate mitigation methods with which the following might help in a general way.</p>\n<p><strong>Hazard Controls</strong></p>\n<p>While the question focuses on masks, a component of Personal Protective Equipment (PPE), one must understand that PPE is the least effective of safety controls. We use it in hospital settings simply because other, more effective controls are impossible or impractical. See the Safety Controls Hierarchy below from National Institute for Occupational Safety and Health (NIOSH) at <a href=\"https://www.cdc.gov/niosh/topics/hierarchy/default.html\" rel=\"noreferrer\">https://www.cdc.gov/niosh/topics/hierarchy/default.html</a> :</p>\n<p><a href=\"https://i.stack.imgur.com/qEmsb.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/qEmsb.jpg\" alt=\"NIOSH Hierarchy of Hazard Controls\" /></a></p>\n<p>Simply as a comparative use of the Hierarchy - in hospitals, we cannot eliminate our infectious patients or substitute them for something benign. But we can use the latter three of the hierarchy:</p>\n<p><strong>Engineering</strong> - we physically isolate particularly infectious patients in rooms with negative airflow.</p>\n<p><strong>Administrative</strong> - hospitals have policies and procedures, based on supportive research and professional organization known best practices, to direct employees in working safely with infectious patients.</p>\n<p><strong>PPE</strong> - we wear use-specific masks, gowns, gloves, shoe covers, head covers, hoods, supplied-air respirators, and other PPE as called for by known best practice for the specific infectious agent. This is the last line of defense against transmission of infection from patient to worker.</p>\n<p>Applying the Hierarchy of Controls to the specific cooking situation is absolutely appropriate and would be more effective than using a single component (N95 masks) of a single point of the hierarchy (PPE). Suggestions:</p>\n<p><strong>Elimination</strong> - Remove oils, stoves, and frying pans from your house. Not really practical, as this only leads to substitution because &quot;a man's gotta eat&quot; (Trailer Park Boys - Randy).</p>\n<p><strong>Substitution</strong> - Cook and eat something different than fried foods. Use a different cooking method that does not involve frying. Eat food known/believed to be more healthy than fried foods. Safety isn't always as fun as doing whatever the heck one wants, but one needs to prioritize. This is also where the human psychology component of safety comes in - I know most people won't eliminate fried foods from their diets, so let's look at some realistic alternatives.</p>\n<p><strong>Engineering</strong> - Each of us probably already has a hood fan over our stove, but does it vent to the outside? Many don't (in U.S. at least). Is it really effective? Could we open a few windows to help clearing of the smoke/chemicals? Have we changed your hood filters according to manufacturer's recommendations? Could we do most or all of the frying outside? A hood fan will not be completely effective, but can be an important component in our safety controls, especially in commercial applications. This also brings up the question of harm to others if we vent to the outside on a commercial scale, i.e., are we just protecting the workers at the expense of innocent others?</p>\n<p><strong>Administrative</strong> - As the administrator of our households, we may set rules for all who cook so that appropriate safety controls will be followed. As the administrator of a restaurant or other commercial food production, one may require, through policy, engineering controls and worker safety procedures.</p>\n<p><strong>PPE</strong> - I think that masks are not necessarily a bad idea for use in cooking, but the mask needs to be the correct type for the given safety hazard else it is a waste of time and money. A few chemicals/compounds were mentioned in the question and each must be accounted for when choosing the correct protection. As a reference, this 3M site details their products appropriate for use in specific applications with specific chemicals: <a href=\"https://www.3m.com/3M/en_US/respiratory-protection-us/applications/\" rel=\"noreferrer\">https://www.3m.com/3M/en_US/respiratory-protection-us/applications/</a> Please note that, although I have received some training from 3M, I am not employed by nor a representative of, and I do not receive compensation from 3M. I am also not specifically recommending their products as there are several other PPE manufacturers with comparable products.</p>\n<p>As one finds the respirator/filter types appropriate for exposure to such things as benzopyrenes and formaldehyde as mentioned in the question, one will also likely decide they are not practical (cost and comfort) for personal use, but might be appropriate for daily exposure at a commercial level. Note that assessment of the amount and exposure time of the hazard is necessary to determine how often filters need to be replaced.</p>\n<p><strong>Final Notes</strong></p>\n<p>We cannot answer the general question of whether N95 masks protect one from cooking chemicals; the question is much too broad. However, I am inclined to opine &quot;<em>heck no</em>&quot;.</p>\n<p>If one is questioning appropriate mask use in a commercial setting, this raises all sorts of legal issues that I am not about to address. Leave those issues to those who regulate the industry in question. Although, I will note that workers generally have a right in the U.S. to voluntarily wear PPE at their own expense - see OSHA standards for details.</p>\n<p>@David West had a great answer. I'm just giving supplemental information for those who may come across this question in the future.</p>\n", "score": 6 } ]
31,856
CC BY-SA 4.0
Can N95 face masks filter out benzopyrene, polycyclic aromatic hydrocarbons or formaldehyde?
[ "cancer", "research", "face-mask-respirator" ]
<p><strong>The Question</strong>: Can N95 face masks filter out benzopyrene, polycyclic aromatic hydrocarbons or formaldehyde?</p> <p><strong>Background</strong>: Pan-frying, stir-frying, and deep-frying typically involve heating oil to a high temperature, resulting in a great amount of smoke [1]. According to previous reports [2–5], various kinds of mutagens and human carcinogens-such as benzopyrene, polycyclic aromatic hydrocarbons, and formaldehyde-could be released from oil into cooking oil fumes, which are then inhaled by the cook.</p> <p>Some now start wearing N95 face masks during pan/stir/deep frying, in hope to reduce the inhalation of those harmful particles. Now, according to <em>Centers for Disease Control and Prevention</em> (CDC), N95 masks filter out contaminants like dusts, mists and fumes. The minimum size of .3 microns of particulates and large droplets won’t pass through the barrier. The question is: would it also filter out the benzopyrenes, the polycyclic aromatic hydrocarbons, and the formaldehydes? The <em>New York State Department of Health</em> claims that N95 masks do not protect you against chemical vapors, gases, carbon monoxide, gasoline, asbestos, lead or low oxygen environments, but that was not very helpful. Any clarification would be greatly appreciated.</p> <p><strong>References</strong>:</p> <ol> <li>Chunyan Wang, Lifang Liu, Xiaoli Liu, Wenjun Chen, Guoping He, Mechanisms of Lung Cancer Caused By Cooking Fumes Exposure: A Minor Review, Chinese Medical Sciences Journal, Volume 32, Issue 3, 2017, Pages 193-197, ISSN 1001-9294, <a href="https://doi.org/10.24920/J1001-9294.2017.026" rel="noreferrer">https://doi.org/10.24920/J1001-9294.2017.026</a>.</li> <li>Chiang, T. A. et al. Mutagenicity and polycyclic aromatic hydrocarbon content of fumes from heated cooking oils produced in Taiwan. Mutation Research-Fundamental and Molecular Mechanisms of Mutagenesis 381, 157–161, <a href="https://doi.org/10.1016/S0027-5107(97)00163-2" rel="noreferrer">https://doi.org/10.1016/S0027-5107(97)00163-2</a> (1997).</li> <li>Chen, J. W., Wang, S. L., Hsieh, D. P. H., Yang, H. H. &amp; Lee, H. L. Carcinogenic potencies of polycyclic aromatic hydrocarbons for back-door neighbors of restaurants with cooking emissions. Science of the Total Environment 417, 68–75, <a href="https://doi.org/10.1016/j.scitotenv.2011.12.012" rel="noreferrer">https://doi.org/10.1016/j.scitotenv.2011.12.012</a> (2012).</li> <li>Qu, Y. H. et al. Genotoxicity of heated cooking oil vapors. Mutat Res 298, 105–111, <a href="https://doi.org/10.1016/0165-1218(92)90035-X" rel="noreferrer">https://doi.org/10.1016/0165-1218(92)90035-X</a> (1992).</li> <li>Thiebaud, H. P., Knize, M. G., Kuzmicky, P. A., Hsieh, D. P. &amp; Felton, J. S. Airborne mutagens produced by frying beef, pork and a soy-based food. Food and Chemical Toxicology 33, 821–828, <a href="https://doi.org/10.1016/0278-6915(95)00057-9" rel="noreferrer">https://doi.org/10.1016/0278-6915(95)00057-9</a> (1995).</li> </ol>
7
https://medicalsciences.stackexchange.com/questions/32188/what-does-current-research-show-regarding-the-use-of-sunscreen-in-deeper-skin-to
[ { "answer_id": 32199, "body": "<blockquote>\n<p>Has any research been done that specifically reviews the effects of sun exposure in people with deeper skin tones...and how effective deeper skin tones are in protecting against UVB/UVA</p>\n</blockquote>\n<p>A brief search comes up with this recent <a href=\"https://academic.oup.com/bjd/article/188/2/168/6815660\" rel=\"nofollow noreferrer\">review</a> that may provide you with a starting point for further research. I believe it addresses all the points you are interested in and provides references that may contain the data you are looking for.</p>\n<blockquote>\n<p>Has any research been done that specifically reviews...the efficacy of sunscreen in the prevention of skin cancer in people with deeper skin tones</p>\n</blockquote>\n<p>The answer appears to be not really. According to the review I linked there is limited data on the affects of sunscreen in patients with varying skin tones.</p>\n<p>I am not a dermatologist or expert in this topic specifically so I cannot say with certainty that I haven't missed something obvious or that this data does not exist out there somewhere. But hopefully this is helpful.</p>\n", "score": 1 } ]
32,188
CC BY-SA 4.0
What does current research show regarding the use of sunscreen in deeper skin tones?
[ "dermatology", "cancer", "research", "basal-cell-carcinoma", "melanoma" ]
<p>I've struggled to find anything at all in the literature that specifically investigates the use of sunscreen as a preventative measure against sun damage in people with deeper skin tones.</p> <p>Furthermore, I've found almost nothing in the literature that seriously investigates the incident rate of various skin cancers in deeper skin tones. What does exist is mostly made in passing, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6369227/" rel="nofollow noreferrer">reviewing general attitudes</a>, or in obscure papers with poor quality control. (Often times the end-points are related to the mortality rate of skin cancers when presented in deeper skin tones, rather than the rate at which they get them or the efficacy of increased melanin content compared to sunscreen to defend against sun damage.)</p> <p><a href="https://www.aad.org/public/diseases/skin-cancer/types/common/melanoma/skin-color#:%7E:text=People%20of%20all%20colors%2C%20including,cancer%20that%20can%20spread%20quickly" rel="nofollow noreferrer">Current guidelines from the AAD</a> (American Dermatology Association) is that &quot;[p]eople of all colors, including those with brown and black skin, get skin cancer. Even if you never sunburn, you can get skin cancer&quot; and as such &quot;[w]ear sunscreen. Yes, people of color should wear sunscreen.&quot;</p> <p>I found virtually no data from African countries that reviewed skin cancer incident rates, outside of <a href="https://www.wcd2019milan-dl.org/abstract-book/documents/abstracts/42-tropical-dermatology/skin-cancer-in-tigray-region-4202.pdf" rel="nofollow noreferrer">one paper in Ethiopia</a> which looked at Tigray Ethiopians.</p> <p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2757062/" rel="nofollow noreferrer">One paper I found states that</a> &quot;Public educational campaigns should expand their efforts to educate people of all skin types <strong>with emphasis on skin cancers occurring in <em>areas not exposed to the sun</em></strong> (Byrd-Miles et al, 2007), <strong>since sunlight is not as important an etiologic factor in the pathogenesis of skin cancer in people of color</strong>.&quot;</p> <p>Yet goes on to say &quot;Sunscreen (sun protection factor 30 or greater) <strong>should be applied to skin, regardless of complexion</strong>, during periods of prolonged exposure, especially during peak hours of sunlight (10 am–2 pm).&quot;</p> <p>I've seen other such recommendations from other serious papers and organizations, yet I've seen no specific data that looks at how sunscreen plays a role in the prevention of skin cancer in people with deeper skin tones.</p> <p>Has any research been done that specifically reviews the effects of sun exposure in people with deeper skin tones, the efficacy of sunscreen in the prevention of skin cancer in people with deeper skin tones, and how effective deeper skin tones are in protecting against UVB/UVA?</p> <p>All emphasis is mine.</p>
7
https://medicalsciences.stackexchange.com/questions/72/for-long-term-use-non-alcoholic-mouthwash-vs-saltwater
[ { "answer_id": 174, "body": "<p>Comparing \"saltwater\" to non-alcoholic mouthwash may be too general.</p>\n\n<p>If I remember correctly, pH is dependent on OH- (hydroxide) and H+ (Hydrogen) levels. Depending on the type of salt, let's say NaCl (table salt), water will recombine with the salt, but OH and H levels aren't affected. Na binds to OH and H binds to CL in equal quantity.</p>\n\n<p>Regarding the following that I found below, I believe \"alkalinize\" can't be taken to mean below neutral. I think it means that it lowers the pH level, whether to basic or less acidic. How I think of it is that you start with a highly acidic environment due to the bacteria. Then you use something with less acidity to average out the pH. </p>\n\n<blockquote>\n <p>\"Salt water rinses are good because they alkalinize the mouth (opposite of acidify, which is what the bacteria create.) Use one-half teaspoon each of baking soda and salt in a cup of warm water. The alkalinity helps decrease the bacteria count because they like an acid environment. As far as hot or cold, I'm not sure it matters. The rise in pH (alkalinity) is temporary. That is why the docs are promoting the Peridex, because they last longer.\"<sup><a href=\"http://www.ped-onc.org/treatment/mouthcare.html\" rel=\"nofollow\">1</a></sup></p>\n</blockquote>\n\n<p>However, I believe that <strong>the acidity is relative</strong>. So for short term, it kills the bacteria, but for long term I believe Dr. Kerr is correct: it erodes teeth, which are made from Ca+ and probably fall to influence of the Cl- present in the solution.</p>\n\n<p>Cetylpyridinium chloride is a modern anti-sceptic. Despite the hazards of LARGE quantity exposure, \"CPC was one of only three antimicrobial systems to be classified as safe and efficacious for the treatment of plaque-induced gingivitis, along with stannous fluoride and essential oils.\"<sup><a href=\"http://www.dentistryiq.com/articles/2011/09/cpc.html\" rel=\"nofollow\">2</a></sup> So it's safe in the amounts we use. Plus, hopefully you're not swallowing your mouthwash.</p>\n\n<hr>\n\n<p><sup><a href=\"http://www.ped-onc.org/treatment/mouthcare.html\" rel=\"nofollow\">1: Ped-Onc Resource Center - Mouth and Teeth: Care and Problems</a></sup></p>\n\n<p><sup><a href=\"http://www.dentistryiq.com/articles/2011/09/cpc.html\" rel=\"nofollow\">2: Cetylpyridinium chloride reduces plaque, calculus</a></sup></p>\n\n<p><sup><a href=\"http://www.wisegeek.com/what-is-cetylpyridinium-chloride.htm\" rel=\"nofollow\">What is Cetylpyridinium Chloride?</a></sup></p>\n", "score": 5 } ]
72
For long-term use: Non-Alcoholic Mouthwash vs Saltwater
[ "dentistry" ]
<p><strong>Foreword:</strong> Please beware that I ask this question only for mouthwash with NO alcohol whatsoever; so please omit alcoholic mouthwashes (which can cause cancer).</p> <p>Since my grandmother continues to develop cavities, she twice daily brushes, flosses, then flosses again with interdental brushes, and concludes with a Crest mouthwash with 0 alcohol (see the footnote). She also abstains from any added sugar or sweeteners.</p> <p><strong>Question 1:</strong> How does saltwater compare with non-alcoholic mouthwash for daily lifelong use? Her dentist does not know of any relevant research, and only recommends saltwater for short-term use. So her dentist agrees with some of the claims <a href="http://www.todaysdentistry.com.au/mouthwash-or-salt-water-rinse/" rel="noreferrer">here</a> by Dentist <a href="http://www.todaysdentistry.com.au/about-us/meet-the-team/our-dentists/" rel="noreferrer">David Kerr</a> (B.DSc (Hons) BSc (Hons), University of Queensland).<br /> <strong>Question 2:</strong> But is Dentist Kerr perfectly right in his criticism (of saltwater) below?</p> <blockquote> <p><a href="http://www.todaysdentistry.com.au/mouthwash-or-salt-water-rinse/" rel="noreferrer">How about using salt water long term?</a></p> <p>Longer term, the salt water is acidic, so there would be a problem if you were to use it every day, it could erode the teeth, but is not necessarily abrasive to the teeth. It is the acidity of the salt water that could eat away and soften the enamel on the teeth making them more susceptible to wearing, chipping and cavities.</p> </blockquote> <p><strong>Footnote:</strong> My grandmother uses this brand because it contains cetylpyridinium chloride, which (<a href="http://www.besthealthmag.ca/best-you/oral-health/6-reasons-to-rinse-well-with-mouthwash?slide=2#l1KdrksIr7zYQBbc.97" rel="noreferrer">this website</a> claims) has 'been proven to reduce plaque or <a href="http://www.besthealthmag.ca/get-healthy/oral-health/6-things-everyone-should-know-about-cavities" rel="noreferrer">fight cavities</a>'.</p>
6
https://medicalsciences.stackexchange.com/questions/105/how-cold-can-an-asthmatics-drinking-water-be
[ { "answer_id": 272, "body": "<p>Drinking cold water having asthma can cause <a href=\"http://en.wikipedia.org/wiki/Bronchospasm\" rel=\"nofollow noreferrer\">bronchial spasm</a>, a sudden constriction of the muscles in the walls of the <a href=\"http://en.wikipedia.org/wiki/Bronchiole\" rel=\"nofollow noreferrer\">bronchioles</a> (tightness in the chest), causing difficulty in breathing. This can be also triggered by <a href=\"http://en.wikipedia.org/wiki/Exercise-induced_bronchoconstriction\" rel=\"nofollow noreferrer\">Exercise-induced asthma (EIA)</a>.</p>\n\n<p><a href=\"http://en.wikipedia.org/wiki/Bronchospasm\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/N04Q6.png\" alt=\"Bronchospasm - Source Wikipedia\"></a></p>\n\n<blockquote>\n <p>The neurotransmitter <a href=\"http://en.wikipedia.org/wiki/Acetylcholine\" rel=\"nofollow noreferrer\">acetylcholine</a> is known to decrease sympathetic response by slowing the heart rate and constricting the <a href=\"http://en.wikipedia.org/wiki/Smooth_muscle_tissue\" rel=\"nofollow noreferrer\">smooth muscle tissue</a>. Ongoing research and successful clinical trials have shown that agents such as <a href=\"http://en.wikipedia.org/wiki/Diphenhydramine\" rel=\"nofollow noreferrer\">diphenhydramine</a>, <a href=\"http://en.wikipedia.org/wiki/Atropine\" rel=\"nofollow noreferrer\">atropine</a> and <a href=\"http://en.wikipedia.org/wiki/Ipratropium_bromide\" rel=\"nofollow noreferrer\">Ipratropium bromide</a> (act as <a href=\"http://en.wikipedia.org/wiki/Receptor_antagonist\" rel=\"nofollow noreferrer\">receptor antagonists</a> of <a href=\"http://en.wikipedia.org/wiki/Muscarinic_acetylcholine_receptor\" rel=\"nofollow noreferrer\">muscarinic acetylcholine receptors</a>) are effective for treating asthma and COPD-related symptoms.<sup><a href=\"http://en.wikipedia.org/wiki/Bronchospasm\" rel=\"nofollow noreferrer\">wiki</a></sup></p>\n</blockquote>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11021003\" rel=\"nofollow noreferrer\">Studies from 2000</a> has been shown that both exercise and drinking ice water can induce <a href=\"http://en.wikipedia.org/wiki/Airway_obstruction\" rel=\"nofollow noreferrer\">airways obstruction</a>, however there is a limited interpretation of results, because of the difficulty of separating the temperature and humidity of the airways during experiments (where airway microcirculation could be <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/1440473\" rel=\"nofollow noreferrer\">an important factor</a>).</p>\n\n<p>So how cold the water should be? I don't think it's possible to answer and it really depends on the individual organism and many other factors. If more studies would follow, it would give you only the averages, nothing more.</p>\n\n<p>The following study used ice water (0-4°C) and warm water 37°C:</p>\n\n<ul>\n<li><p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11021003\" rel=\"nofollow noreferrer\">Effect of ice water ingestion on asthmatic children after exercise challenge.</a> (2000)</p>\n\n<blockquote>\n <p>Thirty Chinese asthmatic children underwent exercise challenge by ergocyclometer for 6 minutes and then were further challenged by immediate ingestion of ice water (200 ml, 0-4 degrees C), warm water (200 ml, 37 degrees C) or no ingestion on three different days in one week. Each patient completed the three different water ingestion tests after exercise challenge.</p>\n \n <p>Exercise-induced asthma (EIA) developed in about two thirds of the 30 patients, regardless of whether ice water, warm water or nothing at all was ingested after exercise challenge. There was no statistically significant difference in spirometric data among the 3 different water tests at various time points.</p>\n \n <p>A statistically significant difference was found between ice water and warm water tests for FEV1 and PEF (p = 0.0293 and p = 0.0308 respectively).</p>\n \n <p><strong>Those who ingested warm water after exercise had a better bronchodilator response than those who ingested ice water.</strong></p>\n</blockquote></li>\n</ul>\n\n<p>If they had ice in it - I don't know. However based on the above you should drink warm water just to be safer.</p>\n", "score": 3 } ]
105
CC BY-SA 3.0
How cold can an asthmatic&#39;s drinking water be?
[ "asthma", "triggers", "water-temperature", "asthma-attack", "exacerbate-exacerbation" ]
<p>For an asthmatic, drinking cold water can apparently trigger (or worsen) an asthma attack. (See <a href="http://integrativepulmonarysleepmedicine.com/asthma" rel="nofollow">here</a> for example.)</p> <p><strong>How cold is cold water for this purpose?</strong></p> <p>I'm trying to find some threshold, between room temperature and ice cold.</p>
6
https://medicalsciences.stackexchange.com/questions/106/how-to-handle-cold-in-summers-with-nose-bleeding-issues
[ { "answer_id": 660, "body": "<p>I can't address how you can avoid your body temperature rising with certain foods like almonds or raisins, as I'm unfamiliar with that issue. Soups can be eaten cold or at room temperature, and you can lower your body temperature slightly with iced drinks, quick sponge baths, etc.</p>\n\n<p>But controlling the most frequent causes of nosebleeds might help you reduce their occurrance.</p>\n\n<p>The vast majority of bloody noses in healthy individuals (by that, I mean people without specific diseases of the blood or mucous membranes, etc.) arise from one specific area in the nose (on either side):</p>\n\n<p><img src=\"https://i.stack.imgur.com/tDxYJ.gif\" alt=\"enter image description here\"></p>\n\n<p>In the mucosa of the nasal septum (the cartilagenous structure separating the nose into two sides), there is an area where several arteries \"meet\", giving it an exceptionally rich vascular supply, called Kiesselbach's plexus. It is on the anterior surface, and exposed to dry air and trauma (even such as might be sustained by a bad cold). People often get nosebleeds from nasal mucosal irritation due to upper respiratory infections. Bleeding typically occurs when the mucosa erodes for any reason, and the capillaries and venules (and sometimes arterioles) become exposed and subsequently break. The result is the familiar bloody dripping of a nosebleed.</p>\n\n<p>The most common treatment is <em>direct pressure</em> (squeezing the sides of the nose together) for 5-10 minutes. This works because putting direct pressure on any bleed stops the blood flow long enough for a clot to form and the arteriole to close down. If needed, more aggressive control can be achieved by a professional.</p>\n\n<p>Besides the immediate treatment of bloody noses, anything that helps with the integrity of the nasal mucosa is going to help reduce nosebleeds. One can </p>\n\n<ul>\n<li>run a humidifier in dry weather</li>\n<li>avoid irritating by touching the nose or blowing nose too often</li>\n<li>apply a very light layer of petrolatum or Bacitracin ointment to the inside of the nose covering Kiesselbach's plexus at night so the nose-breathing doesn't dry out your nose</li>\n<li>use nasal saline spray to moisten and soothe the nasal membranes (don't rub the tip of the spray bottle against the nasal membranes, though) </li>\n</ul>\n\n<p>*more serious or recurrent bleeding needs medical attention to rule out other conditions that are associated with frequent nose bleeds.</p>\n\n<p>Edited to reflect additional information.</p>\n\n<p><sub><a href=\"http://emedicine.medscape.com/article/863220-overview\" rel=\"nofollow noreferrer\">Epistaxis</a></sub></p>\n", "score": 4 } ]
106
How to handle cold in summers with nose bleeding issues?
[ "common-cold" ]
<p>I have a nose bleeding issue from childhood when my body heat gets too high. This can happen from weather, or food like almonds, raisin, dates etc. But I've gotten a bit of a cold during recent weather changes and it has stuck with me. Doctor said to take soup and other hot things, but the weather is already getting warmer and I've already got one nose bleed instance.</p> <p>How can I follow the doctors recommendation to take soup and other warm foods, but still avoid the nosebleeds? (The nosebleed is unrelated to the cold that I have.)</p>
6
https://medicalsciences.stackexchange.com/questions/121/how-can-i-treat-calluses-on-my-palms
[ { "answer_id": 142, "body": "<p>A callus is a thickening of the skin that occurs in response to repeated friction, in order to protect the area that is affected. If you remove the calluses, then you will need to either wear gloves or other protective gear to prevent them from reforming.</p>\n\n<p>Once you have calluses, there are a few ways you can reduce them. It's not recommended to simply cut them off or similar, as the skin underneath will (generally) not be sufficient to protect the area when the stress reoccurs. This can lead to blisters and/or breaks in the skin, which opens up the possibility of infections.</p>\n\n<p>Lotions and soaks such as epsom salts can help soften the area, and then something like a pumice stone can be gently used to abrade away the surface of the callus. Again, do not try to remove the entire area at one time. There are also many home remedies such as soaking in chamomile tea and similar, but I have no experience with their efficacy.</p>\n\n<p>If you wish to prevent them in the future, take note of where on your hands they form, and then look for gloves that have padding in those specific areas. Be aware, that even with good gloves, you may still get callus formation.</p>\n", "score": 3 } ]
121
CC BY-SA 3.0
How can I treat calluses on my palms?
[ "dermatology", "hand", "removal", "calluses" ]
<p>I've been going to the gym for about a year, and because I didn't wear gloves at first, I developed some calluses on my palms.</p> <p>They don't hurt much, but aesthetically, they aren't the most beautiful thing.</p> <p>Is there any way I can treat my hands, so as to remove them completely, or reduce their visibility?</p>
6
https://medicalsciences.stackexchange.com/questions/167/crohns-disease-and-naproxen
[ { "answer_id": 179, "body": "<p>From the <em>World Journal of Gastroenterology</em>, a 2006 submission on Excerabation of IBD by NSAIDS and cox-2 inhibitors: Fact or Fiction, found a weak link between NSAIDs and a IBD flare but some patients will experience a flare up on the medication. The article ends with the recommendation that NSAIDs should be avoided if possible.</p>\n\n<p>However, research done by the NIH, from 1990 to 2008, on 76,000 predominantly white women, found an absolutely increase in incidence of Crohn's disease and ulcerative colitis when the patients were given NSAIDs. They didn't claim it was statistically significant just an absolute increase; this generally occurred with women using the drugs at least 15 days per month.</p>\n\n<ol>\n<li><a href=\"http://www.wjgnet.com/1007-9327/12/1509.pdf\" rel=\"nofollow\">Exacerbation of inflammatory bowel disease by nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 inhibitors: Fact or fiction?</a></li>\n<li><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/22393130\" rel=\"nofollow\">Aspirin, nonsteroidal anti-inflammatory drug use, and risk for Crohn disease and ulcerative colitis</a></li>\n</ol>\n\n<p>You will need PubMed access for article two. Neither article had a definitive answer but extended use seems to be associated with flare ups. </p>\n", "score": 6 } ]
167
CC BY-SA 3.0
Crohn&#39;s disease and naproxen
[ "medications", "side-effects", "crohns" ]
<p>Naproxen has some side effects, <a href="http://www.drugs.com/naproxen.html" rel="nofollow">for example</a>: </p> <blockquote> <p>upset stomach, mild heartburn or stomach pain, diarrhea, constipation;</p> </blockquote> <p>But can it be responsible for ulcerative colitis or a Crohn's desease flare?</p>
6
https://medicalsciences.stackexchange.com/questions/171/what-is-the-process-for-removing-moles-cancerous-or-non-cancerous-from-skin
[ { "answer_id": 203, "body": "<p>There are actually a few ways that moles are removed.</p>\n<h3>Cutting it off</h3>\n<p>Sometimes moles can be &quot;shaved&quot; off if the cells don't go very deep. Other times, the mole cells will be deeper in your skin, so the doctor will have to make a deeper cut to prevent it from coming back (like taking a weed out by its roots). The deeper cuts will usually require stitches. This process is called 'excision'.</p>\n<p>In cases where the mole is suspected to be cancerous, this is always the method used - usually a full excision is performed to make sure no potentially-cancerous cells are left behind.</p>\n<h3>Freezing it off with liquid nitrogen</h3>\n<p>A small amount of liquid nitrogen (which is extremely cold) will be placed on the mole. A small blister might form, but it will heal by itself.</p>\n<h3>Burning it off</h3>\n<p>An electric current is passed through a wire which will burn off the upper layers of the skin (where the mole is) off. Can require multiple treatments.</p>\n<hr />\n<p><a href=\"http://www.webmd.com/skin-problems-and-treatments/tc/removing-moles-and-skin-tags-topic-overview\" rel=\"nofollow noreferrer\"><sup>WebMD - Removing Moles and Skin Tags</sup></a></p>\n<p><a href=\"http://www.wisegeekhealth.com/how-do-doctors-remove-moles.htm\" rel=\"nofollow noreferrer\"><sup>How Do Doctors Remove Moles?</sup></a></p>\n", "score": 6 }, { "answer_id": 219, "body": "<p>Treatment of moles is very dependable to whom you refer for treatment. Dermatologist have more sophisticated methods for mole treatment compared to a general practitioner or a general surgeon.</p>\n\n<p>Major factor influencing to treatment of moles is the possibility of <em>melanoma</em>.</p>\n\n<p>Melanoma should be suspected as follows <a href=\"http://en.wikipedia.org/wiki/Melanoma\" rel=\"nofollow\">1</a>:</p>\n\n<ul>\n<li>Asymmetry </li>\n<li>Borders (irregular)</li>\n<li>Color (variegated)</li>\n<li>Diameter (greater\nthan 6 mm (0.24 in)</li>\n<li>Evolving over\ntime</li>\n</ul>\n\n<p>Melanoma or a suspected melanoma should ALWAYS be treated by surgical incision and removal. Futhermore, the removed skin sample should be sent to pathologist. Of course if mole are treated with laser or other non-invasive methods, adequate histological diagnosis can not be done.</p>\n\n<p>Current medical literature does not describe many proven method for prevention of scars. Whether large scar or even celoid will develop is very patient spesific. Some patients will develop large, very ugly scars and some will have total healing within months. </p>\n\n<p>Silicon containing bands and bandages can be used to treat scar celoid, but the effectiveness of prevention remains unknown. </p>\n", "score": 2 } ]
171
CC BY-SA 3.0
What is the process for removing moles (cancerous or non-cancerous) from skin?
[ "dermatology", "treatment" ]
<p>Moles are underneath or in the deeper parts of the skin I believe. Do they use lasers or something? How do they prevent or try to prevent scarring?</p>
6
https://medicalsciences.stackexchange.com/questions/263/effects-and-side-effects-of-artifical-oxytocin
[ { "answer_id": 3963, "body": "<p>Oxytocin is mainly produced by the body in the following situations:</p>\n\n<ul>\n<li>contractions </li>\n<li>sex </li>\n<li>breastfeeding </li>\n<li>social interaction </li>\n</ul>\n\n<p>It is primarily produced in the hypothalamus of the brain. In pregnant women, it is also produced in the placenta. Synthetic oxytocin is bioidentical, but for obvious reasons not administered in the brain. </p>\n\n<p><strong>Treatment</strong></p>\n\n<p>Synthesized oxytocin is mainly used to induce contractions in women. However, promising studies have been done on patients with schizophrenia:</p>\n\n<blockquote>\n <p>The results revealed that intranasal oxytocin (40 international units twice a day), administered as an adjunct to subjects’ antipsychotic drugs for 3 weeks improved positive and negative symptoms significantly more than placebo </p>\n</blockquote>\n\n<p>In other studies, the same treatment showed no effect:</p>\n\n<blockquote>\n <p>Two small studies failed to detect any functional improvement from the use of intranasal oxytocin (multiple brands) in patients with schizophrenia, even when coupled with social skills training, research presented here indicates.</p>\n</blockquote>\n\n<p>Other studies have been done in patients with autism:</p>\n\n<blockquote>\n <p>Compared with placebo, oxytocin led to significant improvements on the primary outcome of caregiver-rated social responsiveness. </p>\n</blockquote>\n\n<p>As of yet, oxytocin is only used for these conditions in studies. All of the studies so far have been done with small sample sizes. </p>\n\n<p><strong>Side effects</strong></p>\n\n<p>So far, side effects of the nasal spray used in the schizophrenia and autism studies appear to be mild:</p>\n\n<blockquote>\n <p>Overall, nasal spray was well tolerated, and the most common reported adverse events were thirst, urination and constipation</p>\n</blockquote>\n\n<p>From another source:</p>\n\n<blockquote>\n <p>The evidence shows that intranasal oxytocin: (1) produces no detectable subjective changes in recipients, (2) produces no reliable side-effects, and (3) is not associated with adverse outcomes when delivered in doses of 18–40 IU for short term use in controlled research settings. Future research directions should include a focus on the dosage and duration of use, and application with younger age groups, vulnerable populations, and with females.</p>\n</blockquote>\n\n<p>As for the side effects of intravenously administered synthetic oxytocin during labor, there is a lot of information about it on the internet, and very few of it is sourced. Studies are hard to interpret because by design, the groups \"no labor induction\" and \"labor induced\" differ in more than the administration of oxytocin. </p>\n\n<p>The Cochrane review on the topic concludes:</p>\n\n<blockquote>\n <p>For women making slow progress in spontaneous labour, treatment with oxytocin as compared with no treatment or delayed oxytocin treatment did not result in any discernable difference in the number of caesarean sections performed. In addition there were no detectable adverse effects for mother or baby. The use of oxytocin was associated with a reduction in the time to delivery of approximately two hours which might be important to some women. </p>\n</blockquote>\n\n<p><strong>Summary</strong></p>\n\n<p>Synthesized oxytocin probably has no major side effects - however, it is not yet used regularly for any other medical reason than inducing labor. </p>\n\n<p><strong>Sources</strong></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3947469/\" rel=\"noreferrer\">Beyond Labor: The role of natural and synthetic oxytocin in the transition to motherhood</a></p>\n\n<p><a href=\"http://www.nature.com/npp/journal/v37/n1/full/npp2011184a.html\" rel=\"noreferrer\">Oxytocin as a Potential Therapeutic Target for Schizophrenia and Other Neuropsychiatric Conditions</a></p>\n\n<p><a href=\"http://www.medscape.com/viewarticle/850411\" rel=\"noreferrer\">Oxytocin Shows No Effect in Schizophrenia</a></p>\n\n<p><a href=\"http://www.nature.com/mp/journal/vaop/ncurrent/full/mp2015162a.html\" rel=\"noreferrer\">The effect of oxytocin nasal spray on social interaction deficits observed in young children with autism: a randomized clinical crossover trial</a></p>\n\n<p><a href=\"http://www.sciencedirect.com/science/article/pii/S0306453011000862\" rel=\"noreferrer\">A review of safety, side-effects and subjective reactions to intranasal oxytocin in human research</a></p>\n\n<p><a href=\"http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD007123.pub3/full\" rel=\"noreferrer\">Oxytocin versus no treatment or delayed treatment for slow progress in the first stage of spontaneous labour</a></p>\n", "score": 5 } ]
263
CC BY-SA 3.0
Effects and side effects of artifical oxytocin
[ "side-effects", "endocrinology" ]
<p>I have heard that oxytocin </p> <ul> <li>improves mood drastically, </li> <li>is secreted in the body during certain activities, </li> <li>can be synthesized artificially, </li> <li><p>and the artificially synthesized oxytocin can be consumed</p> <ol> <li>Does consumption of artificially synthesized oxytocin cause any side effects?</li> <li>Does the artificially synthesized oxytocin cause the same effects on the body as the hormone which is naturally secreted?</li> </ol></li> </ul>
6
https://medicalsciences.stackexchange.com/questions/282/what-are-the-most-common-sources-of-added-sugars
[ { "answer_id": 317, "body": "<p>The best way to avoid added sugars is to look at the ingredients list for the following items. This list is not complete, but I've organized it into categories to make it easier to remember and draw conclusions about unnamed ingredients.</p>\n\n<p>Obviously, anything labeled \"sugar\", such as:</p>\n\n<ul>\n<li>brown sugar [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>confectioner's powdered sugar [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>]</li>\n<li>invert sugar [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>raw sugar [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>sugar [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>]</li>\n<li>white granulated sugar [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>]</li>\n<li>cane sugar [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>date sugar [<a href=\"http://en.wikipedia.org/wiki/Date_sugar\">4</a>]</li>\n<li>sugar beet/beet sugar [<a href=\"http://en.wikipedia.org/wiki/Sugar_beet\">5</a>]</li>\n</ul>\n\n<p>Many things labeled as \"syrup\"</p>\n\n<ul>\n<li>corn syrup/corn syrup solids [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>high-fructose corn syrup (HFCS) [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>malt syrup [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>maple syrup [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>pancake syrup [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>]</li>\n<li>honey syrup [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n</ul>\n\n<p>Many things labeled as \"juice\"</p>\n\n<ul>\n<li>Evaporated cane juice [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>] (may be listed as 'cane juice', 'cane juice solids', 'cane juice crystals' or dehydrated cane juice)</li>\n<li>Fruit juice concentrates [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>] (or listed as a specific fruit)</li>\n<li>Fruit juice (or listed as a specific fruit)</li>\n</ul>\n\n<p>In chemistry, sugar names end in -ose</p>\n\n<ul>\n<li>dextrose [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>] (also anhydrous dextrose [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>])</li>\n<li>fructose [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>] (also crystalline fructose [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>])</li>\n<li>lactose [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>]</li>\n<li>maltose [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>sucrose [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>glucose [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n</ul>\n\n<p>And some ingredients that you might find in your own kitchen </p>\n\n<ul>\n<li>honey [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>]</li>\n<li>molasses [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>] [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>nectars (e.g., peach nectar, pear nectar) [<a href=\"http://www.choosemyplate.gov/weight-management-calories/calories/added-sugars.html\">1</a>]</li>\n<li>Agave nectar [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n</ul>\n\n<p>Miscellaneous other ingredients that can signal sugars:</p>\n\n<ul>\n<li>cane crystals [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>corn sweetener [<a href=\"http://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/\">2</a>]</li>\n<li>Maltodextrin [<a href=\"http://en.wikipedia.org/wiki/Maltodextrin\">3</a>] </li>\n</ul>\n", "score": 10 }, { "answer_id": 291, "body": "<p>There are a lot of different sources in food products that are added sugar.</p>\n\n<ul>\n<li>High Fructose Corn Syrup - you already mentioned, but this is probably the most common added sugar</li>\n<li>Glucose - also very common</li>\n<li>Honey</li>\n<li>Sucrose</li>\n<li>Lactose</li>\n</ul>\n\n<h3>How to avoid added sugars</h3>\n\n<ul>\n<li><p>Limit yourself when eating sweets</p>\n\n<ul>\n<li>Chocolate is the biggest offender; try dark chocolate instead of plain chocolate or even better, a banana</li>\n</ul></li>\n<li><p>Drink less soda and juice</p>\n\n<ul>\n<li>Many sodas (especially Coca-Cola) and fruit juices are very high in added sugar; you can usually buy less sugary juice</li>\n</ul></li>\n<li><p>Less dairy products - dairy products have a lot of lactose and they have <a href=\"https://health.stackexchange.com/questions/154/are-dairy-products-effective-sources-of-calcium/200#200\">some risks too</a>; milk is usually fine, but ice cream and yogurt are usually high in other types of sugar too</p></li>\n</ul>\n\n<hr>\n\n<p><sup><a href=\"http://www.nhs.uk/livewell/goodfood/pages/top-sources-of-added-sugar-in-our-diet.aspx\" rel=\"nofollow noreferrer\">Top sources of added sugar in our diet</a></sup></p>\n", "score": 2 } ]
282
CC BY-SA 3.0
What are the most common sources of added sugars?
[ "nutrition", "sugar", "labeling" ]
<p>I am also interested in removing as much added sugar from my diet as possible, however I am unfamiliar with what constitutes an added sugar when I look at an ingredient label.</p> <p>Other than the ubiquitous HFSC (High fructose corn syrup), what are the most common added sugars that I should look for in labeling?</p>
6
https://medicalsciences.stackexchange.com/questions/532/is-stomach-acid-an-emulsion
[ { "answer_id": 533, "body": "<p>Well, you eat a number of things - protein, carbohydrates, fats, water, alcohol (at times), etc. Digestion begins in the mouth.The stomach muscles contract periodically, churning food to enhance digestion, breaking it into tiny particles called \"chyme\", which can indeed be an emulsion. The stomach doesn't act as a beaker; it has input and shakes things up.</p>\n\n<p>The chyme is passed into the duodenum, where digestion takes place, and continues through the small intestines. Once the food reaches the large intestion, it is pretty much digested, and water reabsorption takes place.</p>\n\n<p><sub><a href=\"http://www.webmd.com/women/features/stomach-problems\">Surprising Facts About Your Stomach</a></sub></p>\n", "score": 7 } ]
532
CC BY-SA 3.0
Is stomach acid an emulsion?
[ "stomach", "oil", "digestion" ]
<p>It occurred to me that oils float on water, and the stomach is always full of aqueous solution. The stomach empties at the bottom, meaning that oils would only ever pass out of the stomach when it is clear of water, which it never is. Assuming stomach acid is not an emulsion, oils would slowly build up above the water, which would negatively affect health if they never drain. Assuming it is an emulsion, the oils can drain with the aqueous components, and that is that.</p> <p>So does the stomach have some special way of draining oils, or is stomach acid actually an emulsion. In either case, how?</p>
6
https://medicalsciences.stackexchange.com/questions/564/how-much-pesticide-remains-on-a-harvested-organic-fruit
[ { "answer_id": 594, "body": "<p>Washing and peeling conventional fruits and vegetables only helps to reduce the levels of pesticides that may be on the surface as reflected by USDA test data<sup><a href=\"http://envirocancer.cornell.edu/FactSheet/Pesticide/fs24.consumer.cfm\" rel=\"nofollow noreferrer\">1999</a></sup>. As we know the pesticides needs to be toxic to kill pests, therefore potential long-term health effects of exposure to pesticides can include: cancer, neurotoxic effects and many more<sup><a href=\"https://en.wikipedia.org/wiki/Health_effects_of_pesticides#Long-term_effects\" rel=\"nofollow noreferrer\">wiki</a></sup>.</p>\n\n<p>Under the FQPA, EPA has the authority to ensure that all pesticides meet the safety standards. They estimates the exposure to a pesticide from different sources such as food, determine the health risks and set the limits of tolerance which is maximum amount of pesticides that is permitted in/on the food. This is systemically tested as part of the <a href=\"http://toxnet.nlm.nih.gov/cpdb/index.html\" rel=\"nofollow noreferrer\">Carcinogenic Potency Project</a>.</p>\n\n<p>The recent meta-analysis of 343 studies from 2014 shown that organic food has 4 times less <a href=\"https://en.wikipedia.org/wiki/Pesticide_residue\" rel=\"nofollow noreferrer\">pesticide residues</a>, toxic/heavy metals (e.g. Cd and Pb) and other chemicals than in conventional crops which can bioaccumulate in the body over time <sup><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4141693/\" rel=\"nofollow noreferrer\">2014</a></sup>.</p>\n\n<p>According to EWG, buying certain organic food can significantly lower residue exposure<sup><a href=\"https://en.wikipedia.org/wiki/Pesticide_residue#Residues_on_food\" rel=\"nofollow noreferrer\">wiki</a></sup>, because organic crop production standards prohibit the use of synthetic chemical products and certain mineral fertilisers.</p>\n\n<blockquote>\n <p>How much pesticide residue remains on organic food?</p>\n</blockquote>\n\n<p>The toxicology of natural and synthetic chemicals is similar, so it's probable that almost every fruit and vegetable contains natural pesticides<sup><a href=\"http://www.sciencemag.org/content/258/5080/261\" rel=\"nofollow noreferrer\">1992</a></sup>.</p>\n\n<p>One scientific literature notes:</p>\n\n<blockquote>\n <p>What does not follow from this, however, is that chronic exposure to the trace amounts of pesticides found in food results in demonstrable toxicity. This possibility is practically impossible to study and quantify<sup><a href=\"https://en.wikipedia.org/wiki/Organic_food#Consumer_safety\" rel=\"nofollow noreferrer\">wiki</a></sup>.</p>\n</blockquote>\n\n<p>Therefore it's not possible to determine health benefits of eating organic food by measuring how much pesticides remain on food as it really depends on agronomic practices/protocols and soil pollution which can affect crop composition.</p>\n\n<p>Therefore eating organic fruits in general is safe and you shouldn't worry about pesticides too much.</p>\n\n<p><sup>See also: <a href=\"https://health.stackexchange.com/q/343/114\">Are organic foods more healthy than conventional foods?</a></sup></p>\n", "score": 7 }, { "answer_id": 32326, "body": "<p>Organic farming practices generally aim to reduce the use of synthetic pesticides, relying instead on natural pest control methods and approved organic pesticides when necessary. The specific amount of pesticide residue on a harvested organic fruit can vary depending on several factors, including the type of pesticide used, its application method, timing, and adherence to organic regulations.Use <a href=\"https://plantora.app/\" rel=\"nofollow noreferrer\">plant care app</a> for organic farming because it has various remindes like watering, fertilizing, lux meter etc.</p>\n", "score": 0 } ]
564
CC BY-SA 3.0
How much pesticide remains on a harvested organic fruit?
[ "nutrition", "organic" ]
<p>Organic fruits can still be treated with pesticides. I would like to limit my intake (or eliminate entirely) of these pesticides. Has there been any investigation into how much pesticides remain on a harvested organic fruit so that I can make a determination on whether or not to eat the rinds?</p>
6
https://medicalsciences.stackexchange.com/questions/644/is-mint-oil-an-effective-remedy-for-headaches
[ { "answer_id": 671, "body": "<h2>tl;dr</h2>\n\n<p>Peppermint oil combined with ethanol may be useful when applied topically for tension headaches.</p>\n\n<h2>Details</h2>\n\n<p>A review (Kligler) found two studies that looked at peppermint oil when combined with ethanol for the treatment of <strong>tension headache.</strong> They rated the evidence a \"B\" for <strong>\"inconsistent or limited-quality patient-oriented evidence\"</strong></p>\n\n<p>In my own search I only found the same two studies listed in the review. The studies were placebo controlled, double blinded, and random crossover in design, so can be considered good quality experimental design, but they were limited in the number of subjects (one studied 32 patients and the other 41 patients). They did find that <strong>the topical application of peppermint oil and ethanol reduced headache severity.</strong></p>\n\n<p>These studies only considered tension type headaches, so the results may not be applicable to other types of headaches.</p>\n\n<h2>References</h2>\n\n<p>Gobel H, Schmidt G, Soyka D. <a href=\"http://onlinelibrary.wiley.com/doi/10.1046/j.1468-2982.1994.014003228.x/abstract\">Effect of peppermint \nand eucalyptus oil preparations on neurophysiological \nand experimental algesimetric headache parameters.</a> \nCephalalgia 1994;14:228-34.</p>\n\n<p>Gobel H, Fresenius J, Heinze A, Dworschak M, Soyka \nD. <a href=\"http://europepmc.org/abstract/med/8805113\">Effectiveness of oleum menthae piperitae and \nparacetamol in therapy of headache of the tension type</a> \n[German]. Nervenarzt 1996;67:672-81.</p>\n\n<p>Kligler, Benjamin and Sapna Chaudhary. <a href=\"http://www.isdbweb.org/app/webroot/documents/file/910_6.pdf\">Peppermint Oil.</a> American Family Physician. Volume 75, Number 7; April 1, 2007</p>\n", "score": 7 } ]
644
CC BY-SA 3.0
Is mint oil an effective remedy for headaches?
[ "headache", "essential-oil", "migraine", "natural-remedy" ]
<p>Mint oil is often refered to as a remedy for headaches, especially for migraine. </p> <p>For example these articles from health magazines (Article <a href="http://migraine.com/migraine-treatment/natural-remedies/peppermint-oil/" rel="noreferrer">1</a>, <a href="http://thepaleomama.com/2014/01/20-miracle-uses-peppermint-oil/" rel="noreferrer">2</a>, <a href="http://www.healthextremist.com/how-to-use-peppermint-essential-oil-for-headaches/" rel="noreferrer">3</a>), claim that you can reduce headache pains by:</p> <ul> <li>applying a few drops of mint oil to the forehead</li> <li>massaging the temples with mint oil</li> <li>or using a roll-on made from peppermint and lavender essential oil along with some fractionated coconut oil. </li> </ul> <p><strong>Are there studies and/or scientifical proof to back up the claim that mint oil is an effective remedy for headaches?</strong></p>
6
https://medicalsciences.stackexchange.com/questions/657/what-to-substitute-for-milk-in-search-of-sufficient-calcium-and-nutrition
[ { "answer_id": 658, "body": "<p>If you are eliminating milk only, then many of the other dairy sources still hold true as valuable sources of calcium. For example, an 8 ounce serving of fruit yogurt has ~ 300mg of calcium. This would also allow for cheese, which is also in the neighborhood of 300 mg for a 1.5 ounce serving. This makes it fairly easy to avoid milk.</p>\n\n<p>If you eliminate dairy, then your three best sources out of native food are going to be canned salmon, sardines and tofu. The salmon and sardines have calcium because they have the bones included. Tofu is ground up soybeans, and it has about 800mg of calcium per 1 cup. The canned fish is 200-300 depending on the size of the can/serving, etc.</p>\n\n<p>However, what makes it easier is to add fortified foods to your list. A single cup of calcium fortified orange juice has 500mg of calcium. That gets you half way there, and if you make a turkey sandwich with enriched bread and throw on some kale you can easily get to your daily requirement.</p>\n\n<p>If, however, you avoid enriched foods and all dairy, then you probably will need to either eat a lot of tofu or be prepared to eat a lot of varied foods. You can also consider supplements such as vitamins or similar.</p>\n\n<p>For reference from a US based source, the University of California has a <a href=\"http://www.ucsfhealth.org/education/calcium_content_of_selected_foods/\" rel=\"nofollow\">reference page on calcium in food</a>, as does the <a href=\"http://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/\" rel=\"nofollow\">National Institute of Health</a>. Also, google will bring up nutritional information on foods when searched.</p>\n", "score": 6 } ]
657
CC BY-SA 4.0
What to substitute for milk, in search of sufficient calcium and nutrition?
[ "nutrition" ]
<p>In the above title, 'nutrition' is intended to mean the nutrients predominant in milk. (I'm not a biochemist; so I wrote this vaguely.) <a href="http://www.dietitians.ca/Your-Health/Nutrition-A-Z/Calcium/Food-Sources-of-Calcium.aspx" rel="noreferrer">The Dietitians of Canada</a> assert that everybody of ages 19-50 need 1000 mg of Calcium daily. Please omit all those foods (eg <a href="http://greatist.com/health/18-surprising-dairy-free-sources-calcium" rel="noreferrer">these</a>)<br /> from which the quantity needed to satisfy the Recommended Daily Allowance,<br /> cannot be productively consumed.<br /> It's unrealistic to eat daily 5 cups of collards, kale, yogurt; or 10 cups of turnip, etc...</p> <hr /> <p><a href="http://www.hsph.harvard.edu/walter-willett/" rel="noreferrer">Walter Willett</a> MD (Michigan) MPH DPH (Harvard) and <a href="http://www.stmichaelshospital.com/research/profile.php?id=jenkins" rel="noreferrer">David Jenkins</a> DPhil DM (Oxford).</p> <blockquote> <p><a href="http://news.nationalpost.com/2014/01/23/drinking-milk-not-essential-for-humans-despite-belief-it-prevents-osteoporosis-nutritionist-says/" rel="noreferrer">[Source:]</a> But there has been this general belief that we need to consume a lot of milk because that will prevent osteoporosis and fractures. Yet studies that have looked at milk and dairy consumption do not show that people who drink more cow’s milk have lower fracture risk.”</p> <p>“Humans have no nutritional requirement for animal milk, an evolutionarily recent addition to the diet,” Willett and his co-author, David Ludwig, of Boston Children’s Hospital, wrote in an article published last September in the journal, <em>JAMA Pediatrics</em>.</p> </blockquote> <p><a href="http://www.cbc.ca/radio/thecurrent/the-current-for-april-21-2015-1.3041807/got-milked-author-alissa-hamilton-wants-dairy-food-group-gone-1.3041822" rel="noreferrer">This CBC program</a> also doubts milk, and features <a href="http://www.joshgitalis.com/interview-with-dr-alissa-hamilton/" rel="noreferrer">Alissa Hamilton</a> JD (Toronto) PhD (Yale School of Forestry and Environmental Studies) and <a href="https://www.uoguelph.ca/foodscience/sites/uoguelph.ca.foodscience/files/public/Professor%20H%20Douglas%20Goff%27s%20Professional%20Profile.pdf" rel="noreferrer">Prof Douglas Goff</a> MS PhD (Cornell)</p> <p>Footnote: My fears of charlatanism and pseudoscience oblige me to include the postnomials, but sorry if they're excessive.</p>
6
https://medicalsciences.stackexchange.com/questions/749/can-epileptic-seizures-become-life-threatening
[ { "answer_id": 750, "body": "<p>Yes. Most seizures are brief, resolving spontaneously within 1-2 minutes.<sup>1</sup> These are rarely fatal. On the other hand, <em>status epilepticus</em> is not infrequently associated with death. <em>Status epilepticus</em> (sometime referred to in shorthand as just <em>status</em>) just means a prolonged seizure lasting at least 30 minutes. It can also refer to a situation that is technically multiple seizures back-to-back, but without complete return to baseline in between. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25908090\">A recent review of <em>status epilepticus</em> quoted the statistic</a>: </p>\n\n<blockquote>\n <p>The overall mortality associated with status epilepticus approaches 20%, with generalised convulsive status epilepticus representing about 45–74% of all cases.</p>\n</blockquote>\n\n<p>However, it has long been recognized that it is very difficult to know whether the seizure itself or the factor that provoked the seizure is actually responsible for death.<sup>2</sup> The strongest predictor of death from <em>status</em> is the underlying cause. For instance, in <em>status</em> attributable to hypoxia, death occurs over 50% of the time.<sup>1</sup> That is because a seizure is likely to be provoked only by a pretty dire state of hypoxia &mdash; either not responsive to maximal interventions or occurring in a setting where such interventions are not available or not desired.</p>\n\n<p>To the extent that death is directly attributable to the seizure, it is generally because of what doctors often refer has “inability to protect the airway.” Normal, conscious people have reflexes that “protect” the airway at the level of the oropharynx to prevent aspiration. People having a generalized seizure lack such reflexes and can aspirate on their own oral secretions causing hypoxemic respiratory failure. </p>\n\n<hr>\n\n<p><sup>\nReferences\n</sup> </p>\n\n<p><sup>\n1. Betjemann JP, Lowenstein DH. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25908090\"><em>Status epilepticus in adults.</em></a>. Lancet Neurol. 2015 Apr 20. [Epub ahead of print]\n</sup><br>\n<sup>\n2. Jane G. Boggs, M.D. <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC324580/\"><em>Mortality Associated with Status Epilepticus.</em></a> Epilepsy Curr. 2004 Jan; 4(1): 25–27.\n</sup> </p>\n", "score": 7 } ]
749
CC BY-SA 3.0
Can epileptic seizures become life threatening?
[ "neurology", "seizure" ]
<p>Is there any chance of epileptic seizure becoming life threatening or fatal if proper care is not taken?</p>
6
https://medicalsciences.stackexchange.com/questions/773/what-are-the-main-causes-of-myopia
[ { "answer_id": 817, "body": "<p>Nature ran an article <a href=\"http://www.nature.com/news/the-myopia-boom-1.17120\" rel=\"nofollow\">The myopia boom</a> last month, focusing in the explosive increases in cases of myopia in many countries (with some Asian countries going from ~20% in 1940 to ~80% in 2010).</p>\n\n<p>The precise cause is not determined with certainty, but there is a very good correlation between developing myopia and spending time indoors:</p>\n\n<blockquote>\n <p>Researchers have consistently documented a strong association between measures of education and the prevalence of myopia.</p>\n \n <p>[...] </p>\n \n <p>one in five of the children had developed myopia, and the only environmental factor that was strongly associated with risk was time spent outdoors</p>\n \n <p>children who spent more time outside were not necessarily spending less time with books, screens and close work. “We had these children who were doing both activities at very high levels and they didn't become myopic,”</p>\n</blockquote>\n\n<p>The proposed mechanism for this is the lack of light:</p>\n\n<blockquote>\n <p>Retinal dopamine is normally produced on a diurnal cycle — ramping up during the day — and it tells the eye to switch from rod-based, nighttime vision to cone-based, daytime vision. Researchers now suspect that under dim (typically indoor) lighting, the cycle is disrupted, with consequences for eye growth. “If our system does not get a strong enough diurnal rhythm, things go out of control,” says Ashby, who is now at the University of Canberra. “The system starts to get a bit noisy and noisy means that it just grows in its own irregular fashion.”</p>\n</blockquote>\n\n<p>But this is the subject of on-going research, and not everyone agrees. Other factors <em>may</em> also play a part:</p>\n\n<blockquote>\n <p>Some researchers think that the data to support the link need to be more robust. </p>\n \n <p>[..]</p>\n \n <p>He says that the greater viewing distances outside could affect myopia progression, too. “Light is not the only factor, and making it the explanation is a gross over-simplification of a complex process</p>\n</blockquote>\n", "score": 4 } ]
773
CC BY-SA 4.0
What are the main causes of myopia?
[ "eye" ]
<p>Most internet sources when talking about the causes of myopia only tell some variation of the following taken from <a href="http://www.webmd.com/eye-health/nearsightedness-myopia" rel="noreferrer">webmd</a>:</p> <blockquote> <p>People who are nearsighted have what is called a refractive error. In nearsighted people, the eyeball is too long or the cornea has too much curvature, so the light entering the eye is not focused correctly. Images focus in front of the retina, the light-sensitive part of the eye, rather than directly on the retina, causing blurred vision.</p> <p>Nearsightedness runs in families and usually appears in childhood. Usually, the condition plateaus, but it can worsen with age.</p> </blockquote> <p>This tells us that the cause of the refractive error is the too long eyeball or the excessive curvature of the cornea, but nothing about why this may happen other than an observed genetic component.</p> <p>Do we know anything more than this about what causes the eyeball elongation and/or the excessive curvature of the cornea?</p>
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https://medicalsciences.stackexchange.com/questions/819/why-does-my-girlfriend-have-such-smaller-stools-when-we-eat-the-same-food
[ { "answer_id": 1012, "body": "<p>Modern evidence-based medicine won't be able to fully answer your question, but there are indications that <a href=\"https://doi.org/10.1099/00222615-13-1-45\" rel=\"nofollow noreferrer\">bacteria, or more exactly, the individual gut flora heavily influence your fecal weight or stool mass</a>. E.g., in obstipated patients, <a href=\"http://physiolgenomics.physiology.org/content/46/18/679\" rel=\"nofollow noreferrer\">other types of gut bacteria were found than in the control group</a>, which still can't tell what is cause and what is effect. <a href=\"http://www.sciencedirect.com/science/article/pii/S1521691813000577\" rel=\"nofollow noreferrer\">Stool transplantation</a> is also an emerging therapy for various diseases (see also <a href=\"http://www.nature.com/nrgastro/journal/v9/n2/full/nrgastro.2011.244.html\" rel=\"nofollow noreferrer\">here</a> and <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4073534/\" rel=\"nofollow noreferrer\">here</a>), so while there is no better explanation for your question, I think the difference in composition of gut flora may be a good candidate to explain individual variation.</p>\n", "score": 5 } ]
819
CC BY-SA 3.0
Why does my girlfriend have such smaller stools when we eat the same food?
[ "digestion", "fibre", "stools", "defecation" ]
<p>My girlfriend and I have a fairly well-rounded diet. We eat a lot of vegetables, beans, and grains, some dairy and a moderate amount of meat (maybe one serving per day). I would assume our diet to be at least as high in fiber as the average or recommended diet. We both eat at least 3 meals per day and often she eats a slightly larger meal than I do. I have a thin frame and hers is average.</p> <p>But here's where we differ. I defecate generally once or sometimes twice per day, and my output is usually at least a foot long and floats. I think it looks pretty healthy. But she only defecates around once <em>every other day</em> and it is only a relatively small amount of hard deer pebbles.</p> <p>Where does all her waste go? Does she have incredibly efficient enzymes that are making use of the roughage rather than tossing it out? Either way it doesn't seem very healthy for her stool to be so compact, but no amount of fruit or fiber bar eating seems to change the situation.</p>
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