Persius/hicric huggingface dataset:
CYP4F22
CYP4F22 (cytochrome P450, family 4, subfamily F, polypeptide 22) is a protein that in humans is encoded by the CYP4F22 gene.
This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This gene is part of a cluster of cytochrome P450 genes on chromosome 19 and encodes an enzyme thought to play a role in the 12(R)-lipoxygenase pathway. Mutations in this gene are the cause of ichthyosis lamellar type 3.

# Activity
CYP4F22, like other CYP4F proteins, is a Cytochrome P450 omega hydroxylase, i.e. an enzyme that metabolizes fatty acids to their omega hydroxyl derivatives (see Omega oxidation).  This hydroxylation may: a) produce a biologically important signaling molecule such as occurs in the metabolism of 20-carbon straight chain polyunsaturated fatty acid, arachidonic acid, to 20-Hydroxyeicosatetraenoic acid, b) inactivate a biologically important product such as the metabolism of the arachidonic acid metabolite, 5-oxo-eicosatetraenoic acid, to its ~100-fold less potent product, 5-oxo-20-hydroxy-eicosatetraenoic acid, or c) be the first step in the further metabolism of xenobiotics or natural compounds CYP4F22 serves the latter function.  It is a type 1 Integral membrane protein located in the endoplasmic reticulum of cells in the stratum granulosum of mammalian, including human, skin where it functions to attach an omega hydroxyl residue to fatty acids that are exceptionally long, 28 or more carbons, i.e. the very long chain fatty acids (VLCFA).  These VLCFA targets need not be free fatty acids but also can be acylated in an amide bond to sphingosine to form an acylceramide.

# Function
CYP4F22 omega hydroxylates the VLCFA in esterified omega-oxyacyl-sphingosine complex to form an esterified omega-hydroxyacyl-sphingosine complex. This step is critical for delivering the wax-like, extremely hydrophobic VLCFA to the stratum corneum near the skin surface. It is these skin surface VLCFA which create and maintain the skin's ability to function as a water barrier.
CYP4F22, like many of the CYP4F series of CYPs, may prove to serve other functions but its role in hydroxylating VLCFA in the skin's water barrier function, as defined in genetic studies (see below), has dominated research on it.

# Genetic studies
A small number of newborns with Congenital ichthyosiform erythroderma have been found to have autosomal recessive lose of function mutations in CYP4F22. Of the varies subtypes of congenital ichthyosiform erythroderma, these mutations have been associated almost exclusively with the Lamellar ichthyosis subtype.
Capsule
The word capsule, or encapsulation, may refer to:
- Capsule (anatomy), a cover or envelope partly or wholly surrounding a structure.
- Capsule (microbiology), a layer that lies outside the cell wall of bacteria.
- Capsule (pharmacy), a small gelatinous case enclosing a dose of medication.
- Another name for the  sporangium of mosses and hornworts.
- Capsular contracture, the scar tissue naturally forming around breast implants.
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Symptom

# Overview
A symptom is a medical sign indicating the nature of the disease. It is usually subjective, observed by the patient, and not measured.

# Loose definition
A symptom may loosely be said to be a physical condition which indicates a particular illness or disorder.
An example of a symptom in this sense of the word would be a rash. However this is also known as a sign as explained in below.

# Possible causes of a symptom
Some symptoms, such as nausea, occur in a wide range of disease processes, whereas other symptoms are fairly specific for a narrow range of illnesses. For example, a sudden loss of sight in one eye has a significantly smaller number of possible causes.

# Misleading symptoms
Some symptoms can be misleading to the patient or the medical practitioner caring for them. For example, inflammation of the gallbladder often gives rise to pain in the right shoulder, which may understandably lead the patient to attribute the pain to a non-abdominal cause such as muscle strain, rather than the real cause.

# Symptoms and diagnosis
The terms chief complaint, presenting symptom, or presenting complaint is used to describe the initial concern which brings a patient to a doctor. The symptom that leads to a diagnosis is called a cardinal symptom.

# Symptom vs sign
A symptom can more simply be defined as any feature which is noticed by the patient. A sign is noticed by the doctor or others. It is not necessarily the nature of the sign or symptom which defines it, but who observes it.
The same feature may be noticed by both doctor and patient, and so is at once both a sign and a symptom. A sign or a symptom may be one, the other, or both, depending on the observer(s).
Some features, such as pain, can only be symptoms. A doctor cannot feel a patient's pain. Others can only be signs, such as a blood cell count measured by a doctor or a laboratory.

# Engineering definition
In engineering, symptom may be used to refer to an undesired effect occurring in a system. To eliminate the effect, a root cause analysis is performed which traces the symptom to its cause and again through the cause's cause and so on until the subsystem is identified that can be changed to eliminate the symptom.
Cat flu
Cat flu is feline upper respiratory tract disease. It is generally a misnomer since it usually does not refer to an infection by an influenza virus. Instead it is a syndrome: a term meaning any flu-like respiratory disease in a cat. The signs of this disease may be caused by one or more of several different infectious agents (pathogens):
- Official name of causitive agent - (a related more common term)
- Feline viral rhinotracheitis - (cat common cold)
- Feline calicivirus - (cat respiratory disease)
- Bordetella bronchiseptica - (cat kennel cough)
- H5N1 (cat avian flu) (see Global spread of H5N1#Felidae (cats))

# Sources and notes
- Control Cat Flu (future-of-vaccination.co.uk)
- Feline upper respiratory tract disease - Cat Flu (fabcats.org)

# Further reading
- Cat Health (sniksnak.com)
- Cat Care Vaccination (cats.org.uk)
- Cat Flu (yorkcats.org.uk)
- Cat Flu (ae18.com)
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Catador
A Catador (Plural: Catadores) is a Cigar taster/tester in Cuba.
As part of their quality control, cigar factories employ a team to test a random selection of each Torcedor's (Cigar roller) production, so every week the work of each torcedor will have been blind tested.
A Catador will only smoke a small portion of each cigar, and will score each cigar on a scale From Poor to Excellent on the following:
- Appearance and construction
- Aroma
- Burn
- Draw
- Consistency
- Strength
- Flavour
- Quality
In any single session, they will test between 3 and 5 cigars and only drink unsweetened black tea between each cigar tested. The majority of the tests take place in mornings only.
Catechu
Catechu (also known as cutch, cashoo, or Japan earth) is an extract of any of several species of Acaciabut especially Acacia catechuproduced by boiling the wood in water and evaporating the resulting brew.
Catechu (called katha in Hindi) is an astringent and has been used since ancient times in Ayurvedic medicine as well as in breath-freshening spice mixtures.  Black Catechu has recently also been utilized by Blavod Drinks Ltd. to dye their vodka black. 
Also called cutch, it is a brown dye used for tanning and dyeing and for preserving fishing nets and sails.
White cutch, also known as gambier, gambeer, or gambir, has the same uses.
Cathine

# Overview
Cathine (-hydroxyamphetamine) is a monoamine alkaloid found in the shrub Catha edulis (khat).

# Pharmacology
Closely related to ephedrine, cathinone and other amphetamines, it may contribute to the stimulant effect of Catha edulis, although another constituent, cathinone appears to show stronger activity. Cathine is one of the optical isomers of phenylpropanolamine, an appetite suppressant and decongestant which is possibly associated with an increased risk of hemorrhagic stroke.

# Regulation
The World Anti-Doping Agency's list of prohibited substances (used for the Olympic Games among other athletic events) bars cathine in concentrations of over 5 micrograms per milliliter in urine. Cathine is a Schedule III drug under the Convention on Psychotropic Substances. In the United States, it is classified as a Schedule IV controlled substance.
In Hong Kong, Cathine is regulated under Schedule 1 of Hong Kong's Chapter 134 Dangerous Drugs Ordinance. It can only be used legally by health professionals and for university research purporses. The substance can be given by pharmacists under a prescription. Anyone who supplies the substance without prescription can be fined $10000(HKD). The penalty for trafficking or manufacturing the substance is a $5,000,000 (HKD) fine and life imprisonment. Possession of the substance for consumption without license from the Department of Health is illegal with a $1,000,000 (HKD) fine and/or 7 years of jail time.
Catuaba
The name catuaba is used for the infusions of the bark of a number of trees native to Brazil. The most widely used barks are derived from the trees Trichilia catigua and Erythroxylum vacciniifolium. Other catuaba preparations use the bark of trees from the following genera or families : Anemopaegma, Ilex, Micropholis, Phyllanthus, Secondatia, Tetragastris and species from the Myrtaceae.
It is often claimed that catuaba is derived from the tree Erythroxylum catuaba, but this tree has been only described once, (in 1904), and it is not known today to what tree this name referred. The name E. catuaba is therefore not a recognised species (Kletter et al; 2004).
Local synonyms are Chuchuhuasha, Tatuaba, Pau de Reposta, Piratancara and Caramuru. A commercial liquid preparation, Catuama, contains multiple ingredients, one of these being catuaba from Trichilia catigua.
An infusion of the bark is used in traditional Brazilian medicine as an aphrodisiac and central nervous system stimulant. These claims have not been confirmed in scientific studies, but a journalist for the Discovery Channel claims that "reports in scientific journals and at conferences have supported  use for sexual enhancement. In catuaba, a group of three alkaloids dubbed catuabine A, B and C are believed to enhance sexual function by stimulating the nervous system"
A study by Manabe et al. (1992) showed that catuaba extracts from Trichilia catigua were useful in preventing potentially lethal bacterial infections and HIV infection in mice.
Catuaba bark and preparations are sold as aphrodisiacs and remedies for erectile dysfunction in health food stores and through online retailers.
Incisor

# Overview
Incisors (from Latin incidere, "to cut") are the first kind of tooth in heterodont mammals. They are located in the premaxilla.

# Function
In many herbivorous or omnivorous mammals, such as the human and the horse, they are adapted for shearing sharply. In cats, the incisors are small and do not do much; biting off meat is done with the canines and the carnassials. In elephants, the upper incisors are modified into curved tusks, just as is the case with Narwhals, where normally one of them develops into a straight and twisted tusk. The incisors of rodents grow throughout life and are worn by gnawing.

# Number and types of incisors

## In humans
Humans normally have eight (8) incisors, two of each type.  The types of incisors are:
- maxillary central incisor
- maxillary lateral incisor
- mandibular central incisor
- mandibular lateral incisor

## In animals
Among other animals, some other primates, cats and horses have twelve. The rodents have four. Rabbits and hares (lagomorphs) were once considered rodents, but are distinguished by having eight--1 small pair, called "peg teeth" is directly behind the most anterior pair.

### The Rodent incisor
The rodent incisor is one of the evolutionary adaptations that make rodents such a successful group. There are two incisors in the upper jaw and two in the lower jaw. The incisors are separated from the molars by a diastema region, an area without any teeth. The tissue of the incisor is regenerated from the apical end and constantly wears down at the distal tip. The ever-growing incisor can be subdivided into two areas, the crown analogue and the root analogue.
The crown analogue is the labial half of the incisor. It is characterized by an enlarged cervical loop at the apical end. The cervical loop is the epithelial stem cell niche. The epithelial progeny of the crown analogue's cervical loop differentiates into ameloblasts that produce enamel.
The root analogue is the lingual half of the incisor. It's cervical loop is much smaller and the epithelium does not differentiate into ameloblasts, but instead forms a root sheath and fragments into epithelial cell rests of Malassez typical of root epithelium. The root analogue is covered in dentin and cementum like a normal root.

# Additional images
- Mouth (oral cavity)
- Left maxilla. Outer surface.
- Base of skull. Inferior surface.
Chancre
A chancre is a painless ulceration formed during the primary stage of syphilis. This infectious lesion forms approximately 21 days after the initial exposure to Treponema pallidum, the gram-negative spirochaete bacterium yielding syphilis. Chancres transmit the sexually transmissible disease of syphilis through direct physical contact. These ulcers usually form on or around the anus, mouth, penis, and vagina. Chancres may diminish between three to six weeks without the application of medication.  
In addition, chancres are associated with the sleeping sickness, African trypanosomiasis, subsequent to the bite of a tsetse fly.

# Pathological Findings
- Chancres (shang-ker) on the penis due to a primary syphilitic infection.
- Chancre, Syphilis, painless
Reagent
A reactant or reagent is a substance consumed during a chemical reaction. Solvents and catalysts, although they are involved in the reaction, are usually not referred to as reactants.
Although the terms reactant and reagent are often used interchangeably, reagent is often used in a more specialized sense as "a test substance that is added to a system in order to bring about a reaction or to see whether a reaction occurs". Examples of such analytical reagents include Fehling's reagent and Tollens' reagent. In organic chemistry, reagents are compounds or mixtures, usually composed of inorganic or small organic molecules, that are used to effect a transformation on an organic substrate. Examples of organic reagents include the Collins reagent, Fenton's reagent, and Grignard reagent.
In another use of the term, when purchasing or preparing chemicals, "reagent-grade" describes chemical substances of sufficient purity for use in chemical analysis, chemical reactions or physical testing.  Purity standards for reagents are set by organizations such as ASTM International. For instance, reagent-quality water must have very low levels of impurities like sodium and chloride ions, silica, and bacteria, as well as a very high electrical resistivity.
Chervil
Chervil (Anthriscus cerefolium)  is a delicate annual herb related to parsley. Sometimes called garden chervil, it is used to season mild-flavoured dishes and is a constituent of the French herb mixture fines herbes.

# Biology
A member of the Apiaceae, chervil is native to the Caucasus but was spread by the Romans through most of Europe, where it is now naturalised.
The plants grow to 40-70cm, with tripinnate leaves that may be curly. The small white flowers form small umbels, 2.5-5cm across. The fruit is about 1cm long, oblong-ovoid with a slender, ridged beak.

## Root Chervil
Another type of chervil is grown as a root vegetable, sometimes called turnip rooted chervil or tuberous-rooted chervil. This type of chervil produces much thicker roots than types cultivated for their leaves. It was once a popular vegetable in the 19th century. It is now virtually forgotten and is little known in Britain and the United States, root chervil is very common in French cuisine, where it is used in most soups or stews.
Though it looks similar to parsnip it tastes quite different. Parsnips are among the closest relatives of parsley in the umbellifer family of herbs, although the similarity of the names is a coincidence, parsnip meaning "forked turnip". It is not related to real turnips.

# Uses

## Culinary
Sometimes referred to as "gourmet's parsley", chervil is used to season poultry, seafood, and young vegetables. It is particularly popular in France, where it is added to omelettes, salads and soups. More delicate than parsley, it has a faint taste of liquorice.

## Horticulture
Chervil is sometimes used as a trap crop by gardeners to protect vegetable plants from slugs.

## Medical
Chervil had various traditional uses. Pregnant women bathed in an infusion of it; a lotion of it was used as a skin cleanser; and it was used medicinally as a blood purifier.

# Cultivation
Chervil grows to a height of 12 to 26 inches.  Chervil prefers a cool and moist location, otherwise it rapidly goes to seed.
Chigger

# Overview
Chigger or chigoe can refer to either of two parasitic arthropods with similar behaviors: the chigoe flea (Tunga penetrans), found in tropical climates and the larva of a harvest mite that, when carrying a tiny parasite called Orientia tsutsugamushi, causes scrub typhus.  The larvae are also called scrub mite, red mite and several other names, and they are found throughout temperate and tropical zones; the name chigger originated as a corruption of chigoe, but the harvest mite is what is most commonly called a chigger in North America.

# Pathophysiology
- Chiggers do burrow into the skin but do not suck blood. It attaches to its host, injects digestive enzymes into the bite wound, and then sucks up the digested tissue.
- Warm, rainy days make these parasitic and predatory mites reproduce into large populations. Once the ground temperature is regularly above 60F, the harvest mite lays eggs, and chigger season is underway.  This season typically begins in April and ends in the early autumn/first frost.
- Chiggers do not like sunlight or humidity.  During the wet season, chiggers are usually found in tall grass and other vegetation.
- During dry seasons, chiggers are most found underneath brush and shady areas.

# Treatment

## Medical Treatment
To reduce the itching, apply an anti-itch cream that contains hydrocortisone, calamine, or benzyl benzoate. If you are sensitive to these medications or have questions, be sure to ask your health-care professional or pharmacist

## Prevention
- Keep grass short.
- Remove brush and wood debris where potential mite hosts may live.
- Keep major host away from the area, such as - rodents and other small mammals.  Secure trash cans to discourage wildlife from coming near your home.
- Sunlight that penetrates the grass will make the lawn drier and make it less favorable for chigger survival.
- Apply insect repellant to your feet, legs, and mid-section.

# Related Chapters
- Insect bite relief stick
- Schmidt Sting Pain Index
Chordee
Steven C. Campbell, M.D., Ph.D.

# Overview
Chordee is a condition in which the penis curves downward (that is, in a ventral direction). The curvature is usually most obvious during erection, but resistance to straightening is often apparent in the flaccid state as well. In many cases but not all, chordee is associated with hypospadias.

# Presentation
It is usually considered a congenital malformation of unknown cause. Since at an early stage of fetal development the penis is curved downward, it has been proposed that chordee results from an arrest of penile development at that stage.
The curvature of a chordee can involve
- tethering of the skin with urethra and corpora of normal size;
- curvature induced by fibrosis and contracture of the fascial tissue (Buck's fascia or dartos) surrounding the urethra;
- disproportionately large corpora in relation to the urethral length without other demonstrable abnormality of either; or
- a short, fibrotic urethra that tethers the penis downward (the least common type).
Severe degrees of chordee are usually associated with hypospadias, but mild degrees of curvature may occur in many otherwise normal males. When the curved penis is small and accompanied by hypospadias, deficiency of prenatal androgen effect can be inferred.

# Treatment
The principal treatment of chordee is surgery in infancy, usually by a pediatric urologist.
The preferred time for surgery is between the ages of 6 and 18 months, before the child develops castration and body image anxiety.
Correction is usually successful.
Chordin
Chordin is a bone morphogenetic protein antagonist composed of four small cysteine-rich domains, whose function is not known. In humans, the chordin peptide is encoded by the CHRD gene.

# History
Chordin was originally identified in the African clawed frog (Xenopus laevis) in the laboratory of Edward M. De Robertis as a key developmental protein that dorsalizes early vertebrate embryonic tissues.

# Structure
The Chordin polypeptide is 941 amino acids long and 120 kDa large. There are five named isoforms of this protein that are produced by alternative splicing.

# Function
It dorsalizes the developing embryo by binding ventralizing TGF proteins such as bone morphogenetic proteins. It may also play a role in organogenesis.
In mice, Chordin is expressed in the node but not in the anterior visceral endoderm. It has been found to be required for forebrain development. In developing mice that are deficient in both chordin and noggin, the head is nearly absent. This is significant because when only noggin is deficient there are mild defects but the head still forms.
Chordin is also involved in avian gastrulation.  It is expressed in the anterior cells of Koller's sickle, which form the anterior cells of the primitive streak, a key structure through which gastrulation occurs.
Chorion
The chorion surrounds the embryo and other membranes. It consists of two layers: an outer formed by the primitive ectoderm or trophoblast, and an inner by the somatic mesoderm; with this latter the amnion is in contact.
The trophoblast is made up of an internal layer of cubical or prismatic cells, the cytotrophoblast or layer of Langhans, and an external layer of richly nucleated protoplasm devoid of cell boundaries, the syncytiotrophoblast.
It undergoes rapid proliferation and forms numerous processes, the chorionic villi, which invade and destroy the uterine decidua and at the same time absorb from it nutritive materials for the growth of the embryo.
The chorionic villi are at first small and non-vascular, and consist of trophoblast only, but they increase in size and ramify, while the mesoderm, carrying branches of the umbilical vessels, grows into them, and in this way they are vascularized.
Blood is carried to the villi by the branches of the umbilical arteries, and after circulating through the capillaries of the villi, is returned to the embryo by the umbilical veins. Until about the end of the second month of pregnancy the villi cover the entire chorion, and are almost uniform in size, but after this they develop unequally.
The greater part of the chorion is in contact with the decidua capsularis, and over this portion the villi, with their contained vessels, undergo atrophy, so that by the fourth month scarcely a trace of them is left, and hence this part of the chorion becomes smooth, and is named the chorion lve; as it takes no share in the formation of the placenta, it is also named the non-placental part of the chorion.
On the other hand, the villi on that part of the chorion which is in contact with the decidua placentalis increase greatly in size and complexity, and hence this part is named the chorion frondosum.

# Additional images
- Section through the embryo.
- Diagram illustrating early formation of allantois and differentiation of body-stalk.
- Diagram showing later stage of allantoic development with commencing constriction of the yolk-sac.
- Scheme of placental circulation.