Persius/hicric huggingface dataset:
Triphenylmethane

# Overview
Triphenylmethane, or triphenyl methane, is a hydrocarbon. It is a colorless to light brown powder. It is the basic skeleton of many synthetic dyes (Triarylmethane dyes); many of them are pH indicators, and some display fluorescence. It is insoluble in water and soluble in chloroform.
The pKa of the hydrogen on the central carbon is around 31.  Triphenylmethane is significantly more acidic than most other hydrocarbons because the planar trityl anion is stabilized by extensive delocalization over three phenyl rings.  The trityl anion absorbs strongly in the visible region, making it red.   This colour can be used as an indicator when maintaining anhydrous conditions with calcium hydride; the hydride reagent reacts with water to form solid calcium hydroxide, while it is also a strong enough base to generate the trityl anion.  If the hydride is used up then the solution will turn colourless.
Triphenylmethane can be synthesized by Friedel-Crafts reaction from benzene and chloroform with aluminium chloride catalyst. Synthesis from benzylidene chloride, prepared from benzaldehyde and phosphorus pentachloride, is used as well.
Tuberculum impar
During the third week there appears, immediately behind the ventral ends of the two halves of the mandibular arch, a rounded swelling named the tuberculum impar, which was described by His as undergoing enlargement to form the buccal part of the tongue.
More recent researches, however, show that this part of the tongue is mainly, if not entirely, developed from a pair of lateral swellings which rise from the inner surface of the mandibular arch and meet in the middle line.
The tuberculum impar is said to form the central part of the tongue immediately in front of the foramen cecum, but Hammar insists that it is purely a transitory structure and forms no part of the adult tongue.
Tumor metabolome

# Overview
The term tumor metabolome describes the characteristic metabolic phenotype of tumor cells.
Comparison of the metabolic characteristics of different tumor cell lines and tumors revealed that during tumorigenesis, the same alterations always occur in distinct metabolic parameters regardless of the basic metabolism of the tissues from which the tumor developed, such as brain or liver and regardless of the molecular mechanism by which tumorigenesis was induced.
The characteristic attributes of the tumor metabolome are:
- high glycolytic enzyme activities
- the expression of the pyruvate kinase isoenzyme type M2, which is mainly in its dimeric form (= Tumor M2-PK)
- increased channeling of glucose carbons into synthetic processes, such as nucleic acid, amino acid and phospholipid synthesis
- a high rate of pyrimidine and purine de novo synthesis
- a low (ATP+GTP) : (CTP+UTP) ratio
- low AMP levels
- high glutaminolytic capacities
- release of immunosuppressive substances
- dependency on methionine
Type II collagen
Type II collagen is the basis for articular cartilage and hyaline cartilage, formed by homotrimers of collagen, type II, alpha 1 chains.
It makes up 50% of all protein in cartilage and 8590% of collagen of articular cartilage.
Type II collagen does form fibrils. This fibrillar network of collagen allows cartilage to entrap the proteoglycan aggregate as well as provide tensile strength to the tissue. Oral administration of native type II collagen induces oral tolerance to pathological immune responses and may be useful in arthritis.
Tyzzer's disease
Tyzzer's disease  is a contagious bacterial disease in rats and gerbils. It is caused by Clostridium piliforme, formerly known as Bacillus piliformis, a spore-forming bacterium.
It is transmitted horizontally through the fecal-oral route. Animals that carry the bacterium are usually asymptomatic, but a clinical syndrome may be seen in recently weaned rats.
Nonspecific signs such as anorexia, lethargy, emaciation, ruffled fur, or sudden death without clinical signs may be observed.  Mucoid, bloody diarrhea may also be seen. On necropsy, animals may have megaileus. Many other organs, including liver, cecum, colon, and heart, can have characteristic pathologic lesions. Histopathologic observation of bacilli in target organs is diagnostic, and best obtained using a Warthin-Starry silver or Giemsa stain. There is no recommended treatment other than supportive care. Antibiotics effective against Clostridia spp. may be used.
U wave alternans
Synonyms and keywords:
Related chapter: electrical alternans

# Overview
U wave alternans is defined as beat to beat variation in the amplitude or axis of the U wave.

# Classification
U wave alternans is one of several types of repolarization alternans which also includes ST segment alternans and T wave alternans.

# Pathophysiology
The underlying molecular mechanism is thought to involve abnormalities in calcium handling.

# Causes
- Alcoholism
- Hypocalcemia
- Hypokalemia
- Hypomagnesemia
- Pericardial effusion

# Epidemiology and Demographics
U wave alternans is very rare.

# Natural History, Complications, Prognosis
U wave alternans has been associated with an increased susceptibility to ventricular arrhythmias.

# Treatment
Repletion of magnesium and calcium reversed the electrocardiographic abnormality and reduced ventricular irritability.
Ullmann reaction
The Ullmann reaction or Ullmann coupling  is a coupling reaction between aryl halides with copper. The reaction is named after Fritz Ullmann.
A typical example is the coupling of o-chloronitrobenzene to 2,2'-dinitrobiphenyl with a copper - bronze alloy.
The traditional version of the Ullmann reaction requires harsh reaction conditions, and the reaction has a reputation for erratic yields. Since its discovery some improvements and alternative procedures have been introduced.
The reaction mechanism of the Ullmann reaction is extensively studied. Electron spin resonance rules out a radical intermediate. The oxidative addition / reductive elimination sequence observed with palladium catalysts is unlikely for copper because copper(III) is rarely observed. The reaction probably involves the formation of an organocopper compound (RCuX) which reacts with the other aryl reactant in a nucleophilic aromatic substitution. Alternative mechanisms do exist such as -bond metathesis .
The Ullmann reaction is limited to electron deficient aryl halides and requires harsh reaction conditions. In organic synthesis this reaction is often replaced by palladium coupling reactions such as the Heck reaction, the Hiyama coupling and the Sonogashira coupling
In a variation of the Ullmann reaction, 2-bromovinylstyrene is reacted with imidazole in an ionic liquid to an n-vinylimidazole. The reaction requires (L)-proline catalysis.
Unterberger test

# Overview
The Unterberger test, also Unterberger's test and Unterberger's stepping test, is a test used in otolaryngology to help assess whether a patient has a vestibular pathology.  It is not useful for detecting central (brain) disorders of balance.

# Technique
The patient is asked to walk on the spot with their eyes closed.

## Interpretation
If the patient rotates to one side they have a labyrinthine lesion on that side.
Ureidopenicillin
The ureidopenicillins are a group of penicillins which are active against Pseudomonas aeruginosa.  There are three ureidopenicillins in clinical use:
- Azlocillin
- Piperacillin
- Mezlocillin
They are mostly ampicillin derivatives in which the D-side amino chain has been converted to a variety of ureas. It is speculated that the added side chain mimics a longer segment of the peptidoglycan chain, more than ampicillin, and thus would bind more easily to the penicillin-binding proteins. Ureidopenicillins are not resistant to beta-lactamases.
They are used parenterally, and are particularly indicated in infections caused by Gram-negative bacteria.
Urginea maritima
The plant Urginea maritima (syn. Scilla maritima, Urginea scilla, or Drimia maritima) has the common names red squill, sea squill,  sea onion, ein sit, and ada sogani. The name red squill may be reserved for a variety of the plant which has red-tinted flowers instead of the more common white. It may be placed in family Hyacinthaceae with squills of genus Scilla or included in family Liliaceae, depending on which classification system is used.
Sea squill is a bulb which sends up large dull green leaves followed by inflorescences of small white flowers. The bulb can get quite large, reaching over five pounds in weight. It grows in coastal regions in sandy soil.
This squill is native to the Mediterranean but it is widely cultivated. It has been used for medicinal purposes. The bulb contains cardiac glycosides which stimulate the heart and act as diuretics in moderate doses, and are emetic and poisonous in larger doses. The juice of the bulb causes blisters when put in contact with skin. The plant has been used as a rodenticide and may show promise as an insecticide. The most active compounds in the plant are scillirosides, especially proscillaridine A.
In Israel the sea squill has gained an almost iconic status, and is popularly known as the "harbinger of autumn", due to the fact that the flowers pop out all over the country at the end of the dry summer, some time before the first rain.
Urogenital folds

# Overview
The urogenital folds (or urogenital ridges, or urethral folds) are an embryological structure which give rise to a portion of the external genitalia.

# Differentiation
It differentiates into two structures: 
- gonadal ridge -- medial -- primarily reproductive system
- nephrogenic cord -- lateral -- primarily urinary system

# Derivatives
- In the female, the urogenital folds become the labia minora. In contrast, the labia majora are formed by the labioscrotal folds 
- In the male, they form the spongy urethra and a portion of the shaft of the penis, not including the glans.

# Pathology
In the male, failure of the urogenital folds to fuse during development leads to a condition known as hypospadias.

# Obsolete meanings
Less commonly, urogenital fold refers to the fold in the mesonephros which is the precursor of e.g. the suspensory ligament of the ovary. This is the case in older versions of Gray's anatomy. See development of the urinary and reproductive organs, particularily the "The Mesonephros, Mullerian Duct, and Genital Gland" section for this meaning.
Urology robotics

# Overview
Urology Robotics, or URobotics, is a new interdisciplinary field for the application of robots in urology and for the development of such systems and novel technologies in this clinical discipline , . Urology is among the medial fields with the highest rate of technology advances, which for several years has included the use medical robots.

# Applications
The first surgical robot approved by the FDA is the daVinci system. Even though this was designed to assist in general  Laparoscopy, most of its application are in the urology field for radical prostatectomy.
Other, purposely built URobotic systems are under development. These include image-guided robots that in addition to the direct visual feedback use medical images for guiding the intervention. Since MRI provides enhanced visualization of soft-tissues compared to x-ray based imaging, MRI compatible robots are being developed to assist the physician in performing the intervention in the MRI scanner. If prostate cancer lesions can be delineated in the image than robots can accurately target those lesions for biopsy or focal ablations.
Vaginitis causes

# Overview

# Causes
Vulvovaginitis can affect women of all ages and is very common. Specific forms of vaginitis are:

## Causes by Organ System

## Infection
Infectious vaginitis accounts for 90% of all cases in reproductive age women and is represented by the triad:
- Candidiasis: vaginitis caused by Candida albicans (a yeast),
- Trichomoniasis: vaginitis caused by Trichomonas vaginalis (a protozoan),
- Bacterial vaginosis: vaginitis caused by Gardnerella (a bacterium).
Other less common infections are caused by gonorrhea, chlamydia, mycoplasma, herpes, campylobacter and some parasites.
Women who have diabetes frequently develop vaginitis, often Candida albicans more often than women who do not.

## Hormonal
Hormonal vaginitis includes atrophic vaginitis usually found in postmenopausal or postpartum women. Sometimes it can occur in young girls before puberty. In these situations the estrogen support of the vagina is poor.

## Irritation/allergy
Irritant vaginitis can be caused by allergies to condoms, spermicides, soaps, perfumes, douches, lubricants and semen. It can also be caused by hot tubs, abrasion, tissue, tampons or topical medications.

## Foreign body
Foreign body vaginitis: Foreign bodies (most commonly retained tampons or condoms) cause extremely malodorous vaginal discharges. Treatment consists of removal, for which ring forceps may be useful. Further treatment is generally not necessary.

## Role of STI's
Sexually transmitted infections (STIs) can be a cause of vaginal discharge. Chlamydia and gonorrhea testing should be done whenever a sexually active adolescent complains of vaginal discharge even when the cervix appears normal.

## Drug Side Effect
Conjugated estrogens,
Ethynodiol diacetate and ethinyl estradiol,
Metronidazole,
Ofloxacin,
Amoxicillin,

## Causes in Alphabetical Order
Vagovagal reflex

# Overview
Vagovagal reflex refers to gastrointestinal tract reflex circuits where afferent and efferent fibers of the vagus nerve coordinate responses to gut stimuli via the dorsal vagal complex in the brain. The vagovagal reflex controls contraction of the gastrointestinal muscle layers in response to distension of the tract by food.  This reflex also allows for the accommodation of large amounts of food in the gastrointestinal tracts.
The parasympathetic vagus nerve composed of both afferents and efferents carries signals from stretch receptors, osmoreceptors, and chemoreceptors to dorsal vagal complex where the signal may be further transmitted to autonomic centers in the medulla. Efferent fibers of the vagus then carry signals to the gastrointestinal tract up to 2/3 of the Tranverse Colon (coinciding with the second GI watershed point).

# Function
The vagovagal reflex is active during the receptive relaxation of the stomach in response to swallowing of food (prior to it reaching the stomach). When food enters the stomach a "vagovagal" reflex goes from the stomach to the brain, and then back again to the stomach causing active relaxation of the smooth muscle in the stomach wall. If vagal innervation is interrupted then intra-gastric pressure increases.
The vagal afferents are activated during the gastric phase of digestion when the corpus and fundus of the stomach are distended secondary to the entry of a food bolus. The stimulation of the mechanical receptors located in the gastric mucosa stimulates the vagus afferents. The completion of the reflex circuit by vagus efferents leads to the stimulation of postganglionic muscarinic nerves. These nerves release acetylcholine to stimulate two end effects. One, the parietal cells in the body of the stomach are stimulated to release H+. Two, the ECL cells of the lamina propria of the body of the stomach are stimulated to release histamine. Vagal stimulation of the peptidergic neurons, occurring simultaneously, leads to the release of gastrin-releasing-peptide. Finally, the Delta cells are inhibited to reduce the inhibition of gastrin release.
Valgus deformity

# Overview
In orthopedics, a valgus deformity is a term for the outward angulation of the distal segment of a bone or joint.  The opposite of valgus is called varus.
The terms varus and valgus always refer to the direction that the distal segment of the joint points.
For a discussion of the etymology of these words, see the entry under varus.

# Examples
- Hip: coxa valga (from Latin coxa = hip)  the shaft of the femur is bent outward in respect to the neck of the femur, causing bowleggedness.
- Knee: genu valgum (from Latin genu = knee)  the tibia is turned outward in relation to the femur, resulting in a knock-kneed appearance.
- Ankle: talipes valgus (from Latin talus = ankle and Greek pes = foot)  outward turning of the heel, resulting in clubfoot with the person walking on the inner part of the foot.
- Toe: hallux valgus (Latin hallux = big toe)  outward deviation of the big toe toward the second toe.
- Elbows: cubitus valgus (Latin cubitus = elbow)  turned-out elbows
Vasoconstriction
Vasoconstriction is a narrowing of the lumen of blood vessels.

# Factors
Factors that trigger vasoconstriction are both of exogenous origin, i.e. medication, and as a response from the body itself.

## Body mechanisms
Vasoconstriction is a procedure of the body that avoids orthostatic hypotension. It is a part of a body negative feed back loop in which the body tries to restore homeostasis.
For example, vasoconstriction is a hypothermic preventative in which the blood vessels constrict and blood must move at a higher pressure to actively avoid a hypoxic reaction. ATP is used as a form of energy to increase this pressure to heat the body. Once homeostasis is restored the blood pressure and ATP production regulates.

## Medication

# Effects
Vasoconstriction can be a contributing factor to erectile dysfunction.
An increase of blood flow in the penis that builds up causes an erection, however if the body is not functioning properly the blood vessels in the penis activate and allow less blood to pool, meaning the erection goes down prematurely or simply fails to completely go up. This does not necessarily mean that the person in question is not aroused, it is a lapse in judgement between the Central Nervous System  and the Peripheral Nervous System  . When blood pools in the penis the body reacts to the excessive heat to cool it, resulting in vasoconstriction.
Vascular disease

# Overview
Vascular disease is a class of diseases of the blood vessels  the arteries and veins of the circulatory system of the body. It is a subgroup of cardiovascular disease. Disorders in this vast network of blood vessels, can cause a range of health problems which can be severe or prove fatal.

# Associated medical conditions

## Types
There are several types of vascular disease, (which is a subgroup of cardiovascular disease) among them are:
- Peripheral artery disease  happens when atheromatous plaques build up in the arteries that supply blood to the arms and legs, plaque causes the arteries to narrow or become blocked.
- Renal artery stenosis - is the narrowing of renal arteries that carry blood to the kidneys from the aorta.
- Buerger's disease  is due to small blood vessels that inflame and swell, vessels then narrow or are blocked by blood clots.
- Raynaud's disease  a rare disorder of constriction of the peripheral blood vessels, in the fingers and toes when the person is cold.
- Disseminated intravascular coagulation  a widespread activation of clotting in the smaller blood vessels.
- Cerebrovascular diseasea group of vascular diseases that affect brain function.

# Mechanism
Vascular disease is a pathological state of large and medium muscular arteries and is triggered by endothelial cell dysfunction. Because of factors like pathogens, oxidized LDL particles and other inflammatory stimuli endothelial cells become active. The process causes thickening of the vessel wall, forming a plaque that consists of proliferating smooth muscle cells, macrophages and lymphocytes. The plaque results in a restricted blood flow which will decrease the amount of oxygen and nutrients that reach certain organs, the plaque might rupture causing the formation of clots.

# Diagnosis
It can be difficult to make a Vascular disease diagnosis since there are a variety of symptoms that a person can have, also  family history and a physical examination are important. The physical exam may be different depending on the type of vascular disease. In the case of a peripheral vascular disease the physical exam consists in checking the blood flow in the legs.

# Treatment
Treatment varies with the each type of Vascular disease, in the case of Renal artery disease information from a meta-analysis indicated that  balloon angioplasty results in improvement of diastolic blood pressure and a reduction in antihypertensive drug requirements. In the case of Peripheral artery disease preventing complications is important, without treatment sores or gangrene (tissue death) may occur. Among the treatments are: 
- Quit smoking
- Lower cholesterol
- Lower blood pressure
- Lower blood glucose
- Physical activity
Wagner's disease
Synonyms and keywords: Wagners hyaloid retinal degeneration; Wagners vitreoretinal herdodegeneration; Wagner's syndrome.

# Overview
Wagner's Disease is a familial eye disease of the connective tissue in the eye that causes blindness. Wagner's disease was originally described in 1938. This disorder is frequently confused with Stickler's syndrome, but lacks the systemic features and high incidence of retinal detachments. Inheritance is autosomal dominant.
It is a disorder involving the association of hypertension, arteriosclerosis, thickened heart muscle and severe neuroretinitis.

# Historical Perspective
In 1938 Hans Wagner described 13 members of a Canton of Zurich family with a peculiar lesion of the vitreous and retina. Ten additional affected members were observed by Boehringer et al. in 1960 and 5 more by Ricci in 1961. In Holland Jansen in 1962 described 2 families with a total of 39 affected persons. Alexander and Shea in 1965 reported a family. In the last report, characteristic facies (epicanthus, broad sunken nasal bridge, receding chin) was noted. Genu valgum was present in all. In addition to typical changes in the vitreous, retinal detachment occurs in some and cataract is another complication.
Wagner's syndrome has been used as a synonym for Stickler's syndrome. Since there may be more than one type of Wagner syndrome, differentiation from Stickler's syndrome is difficult, and doctors disagree as to whether these are the same entity. It may be that Wagner has skeletal effects, but not the joint and hearing problems of Stickler's syndrome. Blair et al. in 1979 concluded that the Stickler and Wagner syndromes are the same disorder. However, retinal detachment, which is a feature of Stickler' syndrome, was not noted in any of the 28 members of the original Swiss family studied by Wagner in 1938 and later by Boehringer in 1960 and Ricci in 1961.

# Pathophysiology
An exhaustive genetics study of blood from 54 patients found everyone with Wagner's disease has the same eight "markers," a genetic fingerprint that sets them apart from those with healthy eyes.
The gene involved helps regulate how the body makes collagen, a sort of chemical glue that holds tissues together in many parts of the body. This particular collagen gene only becomes active in the jelly-like material that fills the eyeball; in Wagner's disease this "vitreous" jelly grabs too tightly to the already weak retina and pulls it away.

# Treatment
Most people with the disease need laser repairs to the retina, and about 60 per cent need further surgery.
Watershed stroke

# Overview
A watershed stroke is a medical term describing a stroke or cerebrovascular accident (CVA) affecting areas of the brain furthest from direct perfusion with blood supply by the major cerebral arteries.

# Pathophysiology
Watershed strokes result from hypoperfusion (a lack of blood flow), which can be caused by congestive heart failure, severe atherosclerosis of the carotid arteries, or systemic hypotension (shock). Because the brain's circulation is formed by small end-arteries branching from larger central blood vessels, poor perfusion of the brain most strongly affects tissues supplied by the most distal branches of these arteries, producing ischemia and infarction at the border of these watershed areas.
A watershed stroke in the region of overlapped distribution between the anterior cerebral artery and the middle cerebral artery classically presents with weakness of proximal arm and leg muscles and preservation of distal strength: colloquially, the man in a barrel presentation.  This is because this particular region of the brain is responsible for such muscles.