Persius/hicric huggingface dataset:
Rectal foreign body

# Overview
Rectal foreign bodies are in general, large foreign items found in the rectum that can be assumed to have been inserted through the anus, rather than reaching the rectum via the mouth.  Smaller, ingested foreign bodies, such as bones eaten with food, can sometimes be found stuck in the rectum upon x-ray.
Rectal foreign bodies, and amateur attempts to remove them, can result in perforation of the bowel, which is a life-threatening medical emergency.  Medical literature covers examples of items retrieved from patients' rectums. Rectal foreign objects are also the subject of a number of urban legends.

# X Ray Examples
- Rectal foreign body (Image courtesy of Dr Frank Gaillard)
- Rectal foreign body (Image courtesy of Dr Frank Gaillard)
- Rectal foreign body. Body packer. (Image courtesy of Dr Frank Gaillard)
- Rectal foreign body (Image courtesy of Dr Frank Gaillard)
- Rectal foreign body (Image courtesy of Dr Frank Gaillard)
- Rectal foreign body (Image courtesy of Dr Frank Gaillard)

# Case Example
A middle-aged male presented to the emergency department with abdominal discomfort. An abdominal radiograph was performed as shown. There is no evidence of perforation or obstruction. The patient was taken to operating room within 12 hours of presentation, with consent for colostomy. Under general anesthesia in the lithotomy position, dilatation of anal sphincter was performed and per rectum retrieval successful. These patients typically have a delayed presentation to the emergency department because of embarrassment and after multiple attempts at self removal. Respect for their privacy is a key factor in the patients care plan. ED physicians need to decide if removal of foreign body can be performed in the emergency department or surgical team to be notified. Operating room procedures include anal dilatation under GA, transrectal manipulation, bimanual palpation if necessary and withdrawal of foreign body. Laparotomy or laparoscopy are occasionally necessary. (Image courtesy of Andrew Roshan)
Reducing equivalent
In biochemistry, the term reducing equivalent refers to any of a number of chemical species which transfer the equivalent of one electron in redox reactions.  Examples of reducing equivalents are:
- A lone electron (for example in reactions involving metal ions)
- A hydrogen atom (consisting of a proton and an electron)
- A hydride ion (:H) which carries two electrons (for example in reactions involving NAD)
Reed-Sternberg cell
Reed-Sternberg cells (Lacunar Histiocytes for certain types) are distinctive giant cells found on light microscopy in biopsies from individuals with Hodgkin's lymphoma (aka Hodgkin's disease; a type of lymphoma), and certain other disorders. They are derived from B lymphocytes.
They are named after Dorothy Reed Mendenhall (1874-1964) and Carl Sternberg (1872-1935), who provided the first definitive microscopic descriptions of Hodgkin's disease (Reed, 1902; Sternberg, 1898).
Reed-Sternberg cells are large and are either multinucleated or have a bilobed nucleus (thus resembling an "owl's eye" appearance) with prominent eosinophilic inclusion-like nucleoli. Reed-Sternberg cells are CD30 and CD15 positive, usually negative for CD20 and CD45. The presence of these cells is not pathognomonic for the diagnosis of classical Hodgkin's lymphoma.  They can also be found in reactive lymphadenopathy (such as infectious mononucleosis, carbamazepine associated lymphadenopathy) and rarely non-Hodgkin lymphomas.
Reflectory reaction
A reflex action is involuntary and almost instant movement in response to stimulus.  In most contexts, especially involving humans, a reflex action is mediated via the reflex arc (although this is not always true in other animals, or in more casual usage of the term 'reflex'.)
Reflexes are tested as part of a neurological examination to assess damage to or functioning of the central and peripheral nervous system.
Reflexes may be trained, such as during repetition of motor actions during sport practice, or the linking of stimuli with autonomic reactions during classical conditioning.

# Reaction time
For a reflex, reaction time or latency is the time from the onset of a stimulus until the organism responds.
In animals, reaction time to visual stimuli is typically 150 to 300 milliseconds.

# Human reflexes
Reflex actions include:

## Tendon reflexes
The deep tendon reflexes provide information on the integrity of the central and peripheral nervous system. Generally, decreased reflexes indicate a peripheral problem, and lively or exaggerated reflexes a central one.
- Biceps reflex (C5, C6)
- Brachioradialis reflex (C5, C6, C7)
- Extensor digitorum reflex (C6, C7)
- Triceps reflex (C6, C7, C8)
- Patellar reflex or knee-jerk reflex (L2, L3, L4)
- Ankle jerk reflex (Achilles reflex) (S1, S2)
- Plantar reflex or Babinski reflex (L5, S1, S2)
While the reflexes above are stimulated mechanically, the term H-reflex refers to the analogous reflex stimulated electrically, and Tonic vibration reflex for those stimulated by vibration.

## Reflexes involving cranial nerves

## Reflexes in infants only
Newborn babies have a number of other reflexes which are not seen in adults, referred to as primitive reflexes. These include:
- Asymmetrical tonic neck reflex (ATNR)
- Grasp reflex
- Hand-to-mouth reflex
- Moro reflex, also known as the startle reflex
- Sucking
- Symmetrical tonic neck reflex (STNR)
- Tonic labyrinthine reflex (TLR)

## Other reflexes
Other reflexes found in the human nervous system include:
- Anocutaneous reflex
- Bulbocavernosus reflex
- Escape reflex
- Mammalian diving reflex
- Oculocardiac reflex
- Optokinetic reflex
- Photic sneeze reflex
- Scratch reflex
- Withdrawal reflex
Crossed extensor reflex
- Crossed extensor reflex
- Muscular defense
Processes such as breathing, digestion, and the maintenance of the heartbeat can also be regarded as reflex actions, according to some definitions of the term.
Regional anesthesia

# Overview
Regional anesthesia, is anesthesia or (anaesthesia) affecting only a large part of the body, such as a limb. Regional anaesthetic techniques can be devided in central and peripheral techniques. The central techniques include so called neuroaxial blocks epidural anaesthesia, spinal anaesthesia, the peripheral techniques can be further devided in plexus blocks like e.g. the brachial plexus blocks, and single nerve blocks. Regional anesthesia may be performed as a single shot or with a continuous catheter through which medication is given over a prolonged period of time, e.g continuous peripheral nerve block. Last but not least, regional anesthesia can be provided by injecting local anesthetics directly into the veins of an arm (provided the venous flow is impeded by a tourniquette.) This is called intravenous regional techniques (Bier block).
Regional anaesthesia generally involves the introduction of local anaesthetics to block the nerve supply to a specific part of the body, such as a limb, so patients cannot feel pain.

# Indications and applications
Regional anaesthesia may provide anaesthesia (absence of pain) to allow a surgical operation, or provide post-operative pain relief. Various brachial plexus blocks exist for shoulder and arm procedures. Methods similar to routine regional anaesthetic techniques are also often used for treating chronic pain.
In labour and childbirth, epidural or combined spinal epidurals provide effective pain relief. Regional anaesthesia is now more common than general anaesthesia for caesarian section procedures.

# Relationship to other anaesthetic techniques
Unlike general anaesthesia, patients may remain awake during the procedure, resulting in reduced side-effects and enabling the surgeon to converse with the patient during the procedure if required. However, many patients prefer to receive sedation either during 
the block, the procedure, or both.
There is a spectrum of complexity between simple local anaesthetic infiltration and major regional blocks, such as the 'central neuraxial blocks' (spinal and epidural), with nerve blocks lying in the middle. Nerve blocks affecting major peripheral nerves such as the femoral nerve and sciatic nerve are also sometimes viewed as regional anaesthetic techniques.

# Complications
Unlike a minor local anaesthetic infiltration to allow a wound to be sutured, or a skin lesion to be excised, regional anaesthesia may involve large doses of local anaesthetic, or administration of the local anaesthetic very close to, or directly into the central nervous system. Therefore there is a risk of complications from local anaesthetic toxicity (such as seizures and cardiac arrest) and for a syndrome similar to spinal shock.
Most regional anaesthetic techniques, even in expert hands, have a failure rate of 1-10%. Therefore general anaesthesia may become necessary even when a procedure was initial planned to be conducted under a regional technique.
For these reasons, regional anaesthesia is only ever conducted in an environment that is fully equipped and staffed to provide safe general anaesthesia should this be needed.
Rehmannia glutinosa
Rehmannia glutinosa is one of the 50 fundamental herbs used in traditional Chinese medicine, where it has the name dihuang () or gan dihuang ().
One of the traditional uses in traditional Chinese medicine for Rehmannia glutinosa has been in the area of tinnitus and hearing loss.  It turns out that the plant, in fact, seems to have efficacy in the scavenging of free radicals which cause noise related hearing loss.
"A number of constituents such as iridoids, phenethyl alcohol glycosides, glycosides, cyclopentanoid monoterpenes, and norcarotenoids, have been reported from the fresh or processed roots of R. glutinosa."
Relational disorder
According to the American Psychiatric Association, the locus of a relational disorder, in contrast to other DSM-IV disorders, "is on the relationship rather than on any one individual in the relationship (e.g., a parent is withdrawn with one child but not with other siblings).
Despite this major conceptual difference, relational disorders share many elements in common with other disorders: there are distinctive features for classification; they can cause clinically significant impairment; there are recognizable clinical courses and patterns of comorbidity; they respond to specific treatments; and they can be prevented with early interventions. Specific tasks in a proposed research agenda: develop assessment modules; determine the clinical utility of relational disorders; determine the role of relational disorders in the etiology and maintenance of individual disorders; and consider aspects of relational disorders that might be modulated by individual disorders." The proposed new diagnosis defines a relational disorder as "persistent and painful patterns of feelings, behaviors, and perceptions" among two or more people in an important personal relationship, such a husband and wife, or a parent and children.
According to psychiatrist Darrel Regier, MD, some psychiatrists and other therapists involved in couples and marital counseling have recommended that the new diagnosis be considered for possible incorporation into the Diagnostic and Statistical Manual of Mental Disorders (DSM IV). 

# Related Articles
Blatner, Adam M.D.Thinking about the diagnosis of Relational Disorders

# Notes
-  First, Michael B. M.D.A Research Agenda for DSM-V: Summary of the DSM-V Preplanning White Papers Published in May 2002
-  Jump up to: 2.0 2.1 Smith, Michael, Is Your Relationship a Disorder? Review of "Spouse Joust", by Richard Trubo
Renal urea handling

# Overview
Renal urea handling is the part of renal physiology that deals with the reabsorption and secretion of urea.
Urea allows the body to create hyperosmotic urine (urine that has more ions in it--is "more concentrated"--than that same person's blood plasma). Preventing the loss of water in this manner is important if the person's body needs to save water in order to maintain a suitable blood pressure or (more likely,) in order to maintain a suitable concentration of sodium ions in the blood plasma.
About half of the urea filtered (40%) is normally found in the final urine, since there is more reabsorption than secretion along the nephron.
It is regulated by antidiuretic hormone, which controls the amount reabsorbed in the collecting duct system and secreted into the loop of Henle.

# Overview table
Reticulum (anatomy)

# Overview
The reticulum is the second chamber in the alimentary canal of a ruminant animal.  Anatomically it is considered the smaller half of the reticulorumen along with the rumen.
The reticulum is colloqially referred to as the honeycomb. It is also known as the bonnet and as the kings-hood.

# Reference
-  Jump up to: 1.0 1.1 The Chambers Dictionary, Ninth Edition, Chambers Harrap Publishers, 2003
fi:Verkkomaha
Retractor (medical)
A retractor is a surgical instrument that separates the edges of a surgical incision or wound, and holds back underlying organs and tissues, so that body parts under the incision may be accessed. They are available in many shapes, sizes, and styles.
The retractor was invented by Abu al-Qasim, an Islamic physician, over 1000 years ago.

# History
Surgical retractors probably originate with very basic tool use in the Stone Age. Branches or antlers of various shapes were used to dig and extract food from the ground. As the use of tools evolved, a variety of instruments came about to substitute for the use of hooked or grasping fingers in the butchering of meat or dissection of bodies. The use of metals in tool making was of great importance. A variety of Roman metal instruments of the hook and retractor family have been found by archeologists. These instruments would generally be called hooks if the end was as narrow as the handle of the instrument. If the end was broad, it would be called a retractor. Also arising from this group of tools were other related tools for displacing (elevators and spatulas) and scooping (spoons and curettes).
In a description of the procedure of tonsillectomy from the 7th century CE, Paul of Aegina documents the use of a tongue spatula to keep the tongue out of the way while a form of tonsil hook is used to bring the tonsil forward for excision.
In 1000 CE Abu al-Qasim al-Zahrawi, also known as Albucasis or Abulcasis, described a variety of surgical instruments including retractors in his famous text Al-Tasrif.
Vesalius described a variety of hooks and retractors in the 1500's.
Dr. von Mikulicz invention of a hinged rib spreading retractor in 1904 headed a flurry of development in the early 20th century.

# Current
The following is a list of surgical retractors in current use:
- Lahey Retractor
- Senn Retractor
- Blair (Rollet) Retractor
- Rigid Rake
- Flexible Rake
- Ragnell Retractor
- Linde-Ragnell Retractor
- Davis Retractor
- Volkman Retractor
- Mathieu Retractor
- Jackson Tracheal Hook
- Crile Retractor
- Meyerding Finger Retractor
- Little Retractor
- Love Nerve Retractor
- Green Retractor
- Goelet Retractor
- Cushing Vein Retractor
- Langenbeck Retractor
- Richardson Retractor
- Richardson-Eastmann Retractor
- Kelly Retractor
- Deaver Retractor
- Parker Retractor
- Parker-Mott Retractor
- Roux Retractor
- Mayo-Collins Retractor
- U.S. Army Retractor
- Ribbon Retractor
- Alm Retractor
- Self Retaining Retractors
- Gelpi Retractor
- Weitlaner Retractor
- Beckman-Weitlaner Retractor
- Beckman-Eaton Retractor
- Beckman Retractor
- Adson Retractor
- Balfour Retractor
Reversible reaction
A reversible reaction is a chemical reaction that results in an equilibrium mixture of reactants and products. For a reaction involving two reactants and two products this can be expressed symbolically as
A and B can react to form C and D or, in the reverse reaction, C and D can react to form A and B. This is distinct from reversible process in thermodynamics.
The concentrations of reactants and products in an equilibrium mixture are determined by the analytical concentrations of the reagents (A and B or C and D) and the equilibrium constant, K. In turn the magnitude of the equilibrium constant depends on the Gibbs free energy change for the reaction. So, when the free energy change is large (more than about 30 kJ mol-1), the equilibrium constant is large (log K > 3) and the concentrations of the reactants at equilibrium are very small. Such a reaction is called an irreversible reaction. See also irreversibility.

# History
The concept of a reversible reaction was introduced by Berthollet in 1803, after he had observed the formation of sodium carbonate crystals at the edge of a salt lake.
He recognized this as the reverse of the familiar reaction
Until then, chemical reactions were thought to always proceed in one direction. Berthollet reasoned that the excess of salt in the lake helped push the "reverse" reaction towards the formation of sodium carbonate.  Le Chatelier later extended this idea to a more general statement of the effects on equilibrium of various factors.
Rhamnus californica
The California Buckthorn (Rhamnus californica, syn. Frangula californica (Eschsch.) A.Gray) is also called Coffeeberry because its berries contain seeds which look like coffee beans. It is a fairly common plant native to California and southwestern Oregon.
It is an evergreen shrub growing to 2-5 m tall, with dark red branches. The leaves are 2-8 cm long, dark, dull green, and curl under at the edges. The flowers are small and greenish-white with five petals; they are produced in clusters of 5-60 together. The fruit is a berry 10-15 mm diameter, which turns red, then purple and finally black over the summer.
Coffeeberry plants that grow in windy or exposed areas usually do not exceed a meter or two in height or width, but individuals growing in inland areas or sheltered canyons can spread to 8 m wide. The plant is found in shrubby coastal chaparral areas, foothill slopes, and oak woodlands in most regions in California west of the Sierra Nevada, and grows at altitudes of up to 2300 m.
There are two subspecies:
- Rhamnus californica subsp. californica - widespread in western California. Fruit with two seeds; twigs red; leaves with conspicuous veins.
- Rhamnus californica subsp. occidentalis - northern California and southwest Oregon, on serpentine soils. Fruit with three seeds; twigs brown; leaves with inconspicuous veins.
Coffeeberry is susceptible to the mold which causes sudden oak death.

# Uses
Some local native tribes used coffeeberry as an herbal laxative, but only in small quantities since the laxative effects of the plant, as with several other Rhamnus species are quite powerful and even dangerous.
Rifampin overdosage

# Overdosage

## Signs and Symptoms
Nausea, vomiting, abdominal pain, pruritus, headache, and increasing lethargy will probably occur within a short time after ingestion; unconsciousness may occur when there is severe hepatic disease. Transient increases in liver enzymes and/or bilirubin may occur. Brownish-red or orange discoloration of the skin, urine, sweat, saliva, tears, and feces will occur, and its intensity is proportional to the amount ingested.
Liver enlargement, possibly with tenderness, can develop within a few hours after severe overdosage; bilirubin levels may increase and jaundice may develop rapidly. Hepatic involvement may be more marked in patients with prior impairment of hepatic function. Other physical findings remain essentially normal. A direct effect upon the hematopoietic system, electrolyte levels, or acid-base balance is unlikely.
Facial or periorbital edema has also been reported in pediatric patients. Hypotension, sinus tachycardia, ventricular arrhythmias, seizures and cardiac arrest were reported in some fatal cases.

## Acute Toxicity
The minimum acute lethal or toxic dose is not well established. However, nonfatal acute overdoses in adults have been reported with doses ranging from 9 to 12 gm rifampin. Fatal acute overdoses in adults have been reported with doses ranging from 14 to 60 gm. Alcohol or a history of alcohol abuse was involved in some of the fatal and nonfatal reports. Nonfatal overdoses in pediatric patients ages 1 to 4 years old of 100 mg/kg for one to two doses has been reported.

## Treatment
Intensive support measures should be instituted and individual symptoms treated as they arise. The airway should be secured and adequate respiratory exchange established. Since nausea and vomiting are likely to be present, gastric lavage within the first 2 to 3 hours after ingestion is probably preferable to induction of emesis. Following evacuation of the gastric contents, the instillation of activated charcoal slurry into the stomach may help absorb any remaining drug from the gastrointestinal tract. Antiemetic medication may be required to control severe nausea and vomiting.
Active diuresis (with measured intake and output) will help promote excretion of the drug.
For severe cases, extracorporeal hemodialysis may be required. If this is not available, peritoneal dialysis can be used along with forced diuresis.
Right-to-left shunt

# Overview
A right-to-left shunt is a cardiac shunt which allows, or is designed to cause, blood to flow from the right heart to the left heart.  This terminology is used both for the abnormal state in humans and for normal physiological shunts in reptiles. A right-to-left shunt occurs when there is an opening or passage between the atria, ventricles, and/or great vessels. For it to be considered a right to left shunt, the right heart pressure has to be higher than the left heart pressure and/or the shunt has a one-way valvular opening.

# Causes

## Common Causes
The most common cause of right-to-left shunt is the Tetralogy of Fallot, a congenital cardiac anomaly characterized by four co-existing heart defects.
The four defects include:
- Pulmonary stenosis (narrowing of the pulmonary valve and outflow tract, obstructing blood flow from the right ventricle to the pulmonary artery)
- Ventricular septal defect  (defect in the ventricular septum, which divides the left and right ventricles of the heart)
- Overriding aorta (aortic valve is enlarged and appears to arise from both the left and right ventricles instead of the left ventricle, as occurs in normal hearts)
- Right ventricular hypertrophy (thickening of the muscular walls of the right ventricle)
- Ebstein's anomaly

# Natural History, Complications and Prognosis
A frequent complication resulting from a right to left shunt is hypoxemia.
Right main bronchus
The right main bronchus (or right primary bronchus, or right principal bronchus), wider, shorter, and more vertical in direction than the left, is about 2.5 cm. long, and enters the right lung nearly opposite the fifth thoracic vertebra.
The azygos vein arches over it from behind; and the right pulmonary artery lies at first below and then in front of it.
About 2 cm. from its commencement it gives off a branch to the upper lobe of the right lung.
This is termed the eparterial branch of the bronchus, because it arises above the right pulmonary artery.
The bronchus now passes below the artery, and is known as the hyparterial branch; it divides into two branches for the middle and lower lobes.

# Additional images
- Anatomy of lungs.
- The tracheobronchial lymph glands.