Persius/hicric huggingface dataset:
Ether lipid
Ether lipids are lipids in which one or more of the carbon atoms on glycerol is bonded to an alkyl chain via an ether linkage, as opposed to the usual ester linkage.

# Types
Ether lipids are called plasmalogens (1-O-1'-alkenyl-2-acylglycerophospholipids) if these are glycerol-containing phospholipids with an unsaturated O-(1-alkenyl) (vinyl ether) group at the first position on the glycerol chain.
Platelet-activating factor is an ether lipid which has an acetyl group instead of an acyl chain at the second position (SN-2).

# Biosynthesis
The formation of the ether bond in mammals requires two enzymes, dihydoxyacetonephosphate acyltransferase (DHAPAT) and alkyldihydroxyacetonephosphate synthase (ADAPS), that reside in the peroxisome.   Accordingly, peroxisomal defects often lead to impairment of ether-lipid production.

# Functions

## Structural
Plasmalogens as well as some 1-O-alkyl lipids are ubiquitous and sometimes major parts of the cell membranes in mammals and anaerobic bacteria. In archaea, ether lipids are the major polar lipids in the cell envelope and their abundance is one of the major characteristics that separate this group of prokaryotes from the bacteria. In these cells, diphytanylglycerolipids or bipolar macrocyclic tetraethers can form covalently linked 'bilayers'.

## Second messenger
Differences between the catabolism of ether glycerophospholipids by specific phospholipases enzymes might be involved in the generation of lipid second messenger systems such as prostaglandins and arachidonic acid that are important in signal transduction. Ether lipids can also act directly in cell signaling, as the platelet-activating factor is an ether lipid signaling molecule that is involved in leukocyte function in the mammalian immune system.

## Antioxidant
Another possible function of the plasmalogen ether lipids is as antioxidants, as protective effects against oxidative stress have been demonstrated in cell culture and these lipids might therefore play a role in serum lipoprotein metabolism. This antioxidant activity comes from the enol ether double bond being targeted by a variety of reactive oxygen species.

# Synthetic ether lipid analogs
Synthetic ether lipid analogs have cytostatic and cytotoxic properties, probably by disrupting membrane structure and acting as inhibitors of enzymes within signal transmission pathways, such as protein kinase C and phospholipase C.
A toxic ether lipid analogue miltefosine has recently been introduced as an oral treatment for the tropical disease leishmaniasis, which is caused by leishmania, a protozoal parasite with a particularly high ether lipid content in its membranes.
Ethisterone

# Overview
Ethisterone (pregneninolone, 17-ethynyltestosterone or 19norandrostane) is a progestin. It is the 17-ethynyl analog of testosterone, and was synthesized in 1938 by Hans Herloff Inhoffen, Willy Logemann, Walter Hohlweg, and Arthur Serini at Schering AG in Berlin and marketed in Germany in 1939 as Proluton C and by Schering in the U.S. in 1945 as Pranone. It was the first orally-active progestin.
Ethisterone was also marketed in the U.S. from the 1950s into the 1960s under a variety of trade names by other pharmaceutical companies that had been members of the pre-World War II European hormone cartel (Ciba, Organon, Roussel).

# Synthesis
Ethisterone is made by the ethynylation of androstenolone with acetylene and successive oxidation of the hydroxyl group at C3 of the steroid system.
Ethyl group
In chemistry, an ethyl group is an alkyl functional group derived from ethane (C2H6).  It has the formula -C2H5 and is very often abbreviated -Et.
"Ethyl" was also the common designation in North America for high-performance commercial gasoline containing lead in the mid 20th century.  The term comes from the name of the company, Ethyl Corporation, which manufactured the antiknock organometallic agent tetraethyl lead added to the gasoline.
Ethylation is the formation of a compound by introduction of the ethyl functional group, C2H5.
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Ethyl Green
The dye Ethyl Green (Brilliant Green, C.I. 42590; C27H35N3ClBr), due to its powerful bacteriostatic properties, is commonly used along with iodine tincture as a topical antiseptic in Eastern Europe and Russia (common name, Russian tr.:Zelyonka), though not in the west due to its irritant properties and toxicity if ingested. It is soluble in water.
Ethyl green is made of crystal violet by adding an ethyl group; crystal violet is therefore a possible contaminant.
Methyl green is a closely related dye used as a stain in histology. Methyl green and ethyl green are very similar and probably interchangeable.
Etonitazene
Etonitazene is a highly potent narcotic analgesic (10001500x morphine). It's the one of several benzimidazole opioids, and is structurally related to clonitazene (where the p-ethoxybenzyl group is replaced by a p-chlorobenzyl group. However, clonitazene itself has only 3x the potency of morphine.).
It has a strong dependency potential similar to that of morphine and therefore is not used in humans. It is, however, useful in addiction studies on animals.
It is the most potent benzimidazole opioid currently known. Other analogues of considerable potency are as follows:
- Methyl (10x morphine)
- Ethyl (30x morphine)
- Propyl (50x morphine)
- Methoxy (100x morphine)
- Isopropoxy (500x morphine)
- Butoxy (200x morphine)
- Methylthio (50x morphine)
- Ethylthio (30x morphine)
These groups replace the p-ethoxy group - there are other possible modifications but these are the most significant.
The drug has proved very important in mapping out the opiate receptor and some experimental compounds in which phenolic groupings have been replaced with nitro groupings have proved more active than the parent compound.
Illicit production and sale of etonitazene has been limited. This compound was identified on the illegal drug market in Moscow in 1998, appeared to have been illicitly manufactured, and was primarily smoked. In another case a chemist at Morton Thiokol called Thomas K Highsmith Hovey    produced the compound and placed it in a nasal inhaler. Such was the level of his addiction, insufficient amounts of methadone were given and he committed suicide before the case went to court
Euchromatin
Euchromatin is a lightly packed form of chromatin that is rich in gene concentration, and is often (but not always) under active transcription. Unlike heterochromatin, it is found in both eukaryotes and prokaryotes.

# Structure
The structure of euchromatin is reminiscient of an unfolded set of beads along a string, where those beads represent nucleosomes. Nucleosomes consist of eight proteins known as histones, with approximately 146 base pairs of DNA wound around them; in euchromatin this wrapping is loose so that the raw DNA may be accessed. Each core histone possesses a `tail' structure which can vary in several ways; it is thought that these variations act as "master control switches" which determine the overall arrangement of the chromatin. In particular, it is believed that the presence of methylated lysine 4 on the histone tails acts as a general marker for euchromatin.

# Appearance
Euchromatin generally appears as light-colored bands when stained in GTG banding and observed under an optical microscope; in contrast to heterochromatin, which stains darkly. This lighter staining is due to the less compact structure of euchromatin. It should be noted that in prokaryotes, euchromatin is the only form of chromatin present; this indicates that the heterochromatin structure evolved later along with the nucleus, possibly as a mechanism to handle increasing genome size and therefore a decrease in safety/manageability.

# Function
Euchromatin participates in the active transcription of DNA to mRNA products. The unfolded structure allows gene regulatory proteins and RNA polymerase complexes to bind to the DNA sequence, which can then initiate the transcription process. Not all euchromatin is necessarily transcribed, but in general that which is not is transformed into heterochromatin to protect the genes while they are not in use. There is therefore a direct link to how actively productive a cell is and the amount of euchromatin that can be found in its nucleus. It is thought that the cell uses transformation from euchromatin into heterochromatin as a method of controlling gene expression and replication, since such processes behave differently on densely compacted chromatin- this is known as the `accessibility hypothesis'.
Excoriation
An excoriation is an erosion or destruction of the skin by mechanical means, which appears in the form of a scratch or abrasion of the skin. It is commonly seen in other skin disorders causing itching/pruritus: dry skin, dermatitis, atopic dermatitis, scabies, etc. The condition is characteristic of a symptom of other illnesses like liver failure where pruritus is caused by increases of bilirubin.
The term can be associated with neurotic excoriations. Neurotic excoriations are considered psychiatric in etiology. A patient with neurotic excoriations should try to avoid picking and scratching their skin. Because of this, another diagnosis should be made if the lesions are found on areas where the hands do not make contact. It doesn't exclude the possibility, but makes it less likely. The disorder is typically found among females more than males. Damage is common on the face, neck, back, and extremities, and damage to the skin is generally caused by rubbing, scratching, and picking. Severe itching from other causes may mimic this disorder.
Diagnosis is often made by exclusion and is identified and isolated by bandaging areas affected unless any improvement to the affected area or significant change in behavior is witnessed.
Treatment may include periodic bandaging, psychiatric guidance with life adjustments, lotions with or without menthol and phenol (hopefully to take the place of scratching).  Antidepressants may work in patients with neurotic excoriations. Other medications like bedtime antihistamines, antipruritic, sometimes pimozide, or topical corticosteroids are used if there is another reason for the scratching. These are reserved for other conditions and further work up should be pursued.
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Exfoliation
Exfoliation has several meanings:
- Exfoliation (botany) describes the loss of leaves (or, in some cases, pieces of bark) from a plant.
- Exfoliation (cosmetology), is a cosmetic technique aimed at removing dead skin cells from the face and body.
- Exfoliation (geology) is a weathering process.
- Exfoliation (material science) is the process responsible for breaking up particle aggregates.
FG syndrome
Synonyms and keywords: Opitz-Kaveggia syndrome; Keller syndrome; FGS; FGS1; mental retardation, large head, imperforate anus; congenital hypotonia, and partial agenesis of the corpus callosum; OKS

# Overview
FG syndrome is a rare genetic syndrome linked to the X chromosome and causing physical anomalies and developmental delays.

# Historical Perspective
First reported by Opitz and Kaveggia in 1974,  the name of the syndrome comes from the initials of the surnames of two sisters, who had five sons with the syndrome.  The first study of the syndrome, published in 1974, established that it was linked to inheritance of the X chromosome.
A 2008 study concluded that Kim Peek, who was the basis for the Dustin Hoffman character in the movie Rain Man, probably had FG syndrome.

# Pathophysiology

## Genetics
- Researchers have identified five regions of the X chromosome that are linked to FG syndrome in affected families.  In one of these regions, a mutation in a particular gene called MED12 has been found to cause the disorder. Researchers are investigating genes in other regions of the X chromosome that may also be associated with FG syndrome.
- The MED12 gene provides instructions for making a protein that helps regulate gene activity.  Specifically, the MED12 protein forms part of a large complex (a group of proteins that work together) that turns genes on and off. The MED12 protein is thought to play an essential role in development both before and after birth.
- Researchers have identified one mutation in the MED12 gene in several people with FG syndrome.  Although the mutation alters the structure of the MED12 protein, it is unclear how this change leads to intellectual disability, behavioral changes, and the physical features associated with this condition.

# Epidemiology and Demographics
The prevalence of FG syndrome is unknown, although several hundred cases have been reported worldwide. Researchers suspect that FG syndrome may be over diagnosed because many of its signs and symptoms are also seen with other disorders.

# Natural History, Complications and Prognosis
About a third of reported cases of individuals with FG syndrome die in infancy, usually due to respiratory infection; premature death is rare after infancy.

# Diagnosis

## Symptoms
- Mental retardation  usually severe;
- Hyperactive behavior, often with an outgoing personality;
- Severe constipation
- Seizures

## Physical Examination

### Appearance of the Patient
- Short stature

### Head
- Macrocephaly
- Prominent forehead

### Eyes
- Hypertelorism
- Down-slanting palpebral fissures

### Throat
- Droopy, "open-mouthed" expression, a thin upper lip, a full or pouting lower lip due to hypotonia

### Abdomen
- Inguinal hernia

### Extremities
- Broad thumbs and great toes

### Neurologic
- Severe hypotonia

### Others
- Imperforate anus may be present
- Undescended testes (cryptorchidism)

## Laboratory Findings

### MRI
Partial or complete loss of corpus callosum
FLNC (gene)
Filamin-C (FLN-C) also known as actin-binding-like protein (ABPL) or filamin-2 (FLN2) is a protein that in humans is encoded by the FLNC gene. Filamin-C is mainly expressed in cardiac and skeletal muscles, and functions at Z-discs and in subsarcolemmal regions.

# Structure
Filamin-C is a 290.8 kDa protein composed of 2725 amino acids. Filamin-C, like the ubiquitously-expressed isoform Filamin-A, have an N-terminal filamentous actin-binding domain, followed by a lengthy C-terminal self-association domain containing a series of immunoglobulin-like domains, and a membrane glycoprotein-binding domain. Filamin-C interacts with -sarcoglycan and -sarcoglycan at the sarcolemma; myotilin and FATZ/calsarcin/myozenin at Z-lines, as well as LL5. Filamin-C has also been shown to interact with INPPL1, KCND2, and MAP2K4.

# Function
The family of Filamin proteins crosslink actin filaments into orthogonal networks in cortical cytoplasm and participate in the anchoring of membrane proteins for the actin cytoskeleton. However, the precise function of the Filamin-C isoform is still under investigation. As Filamin-C is localized mainly to striated muscle, its functions are likely specific to the specialized sarcomeric cytoskeleton present in muscle. As Filamin-C is found at both subsarcolemmal regions and at Z-lines, one plausible function of Filamin-C would be to act as a mode of communication between the membrane and the sarcomere. In skeletal muscle, Filamin-C is found at sites of core formation in skeletal myopathies, and alterations in subcellular localization of Filamin-C have been exhibited in limb-girdle muscular dystrophy and Duchenne muscular dystrophy.

# Clinical significance
Mutations in Filamin C have been associated with human hypertrophic cardiomyopathy, restrictive cardiomyopathy and a higher incidence of sudden cardiac death. Expression of mutant protein in rat cardiac cells demonstrated that mutant Filamin C forms aggregates, which may provide a mechanistic link to the observed cardiac dysfunction. Deficiency of this protein has been associated with muscle weakness.
False alarm
A false alarm, also called a nuisance alarm, is the phony report of an emergency, causing unnecessary panic and/or bringing resources (such as fire engines) to a place where they are not needed.  Over time, repeated false alarms in a certain area may cause occupants to start to ignore all alarms, knowing that each time it will likely be a fake.  The concept of this can be traced at least as far back as Aesop's story of The Boy Who Cried Wolf, where many episodes of a boy falsely yelling "wolf" caused the townspeople to ignore his cries when a real wolf came.  In addition, false alarms have the potential of diverting emergency responders away from legitimate emergencies, which could ultimately lead to loss of life.
In industrial alarm management, a false alarm could refer either to an alarm with little information content that can usually safely be eliminated, or one that could be valid but is triggered by a faulty instrument.  Both types are problematic because of the "cry wolf" effect described above.
The term "false alarm" is actually a misnomer, and is regularly replaced by the term "nuisance alarm."  When a sensor operates, it is hardly false, and it is usually a true indication of the present state of the sensor.  A more appropriate term is nuisance, indicating that the alarm activation is inconvenient, annoying, or vexatious.  A prime example of this difference is burglar alarms being set off by spiders. (A spider crawling on a web in front of the motion detector appears very large to the motion detector.) 
One tragic example of the consequences of continued false alarms was at Boland Hall at Seton Hall University on January 19, 2000.  Months of false alarms caused many students to start ignoring the fire alarms.  However, when an actual fire broke out, three students who ignored the alarms died, and many others suffered injuries.
Likewise, after too many audible car alarms are found false, most people no longer pay attention to see whether someone is stealing a vehicle, so even certain experienced thieves may confess that these alarms would not deter them from stealing vehicles.

# Other uses
In (signal) detection theory, a false alarm occurs where a non-target event exceeds the detection criterion and is identified as a target (see Constant false alarm rate).
False alarms could also refer to situations where one becomes startled about something that is later determined to be untrue.
Retinopathy

# Overview
Retinopathy is a general term that refers to some form of non-inflammatory damage to the retina of the eye. Most commonly, it is a problem with the blood supply that is the cause for this condition.
Frequently, retinopathy is an ocular manifestation of systemic disease.

# Causes
The main causes of retinopathy are:
- Diabetes  - diabetic retinopathy
- Arterial hypertension - hypertensive retinopathy
- Prematurity of the newborn - retinopathy of prematurity (ROP)
- Sickle cell anemia
- Direct sunlight exposure - solar retinopathy
- Medicinal products - drug-related retinopathy- Hydroxychloroquine,  Interferon alfa-2b , Tamoxifen, Trifluoperazine
- Retinal vein or artery occlusion

# Prognosis
Many types of retinopathy are progressive and may result in blindness, severe vision loss, or impairment, particularly if the macula becomes affected.

# Treatment
Retinopathy is diagnosed by an optometrist or an ophthalmologist during ophthalmoscopy. Treatment depends on the cause of the disease.

# Related Chapters
- List of eye diseases and disorders
- List of systemic diseases with ocular manifestations
Felypressin
Felypressin is added to some local anaesthetics such as prilocaine in a concentration of 0.003 i.u./ml. Felypressin is a non-catecholamine vasoconstrictor that is chemically related to vasopressin, the posterior pituitary hormone. Felypressin is a V1 Agonist, and will thus have affects at all V1 receptors. It will, however, have its main physiological effects on vascular SMC's due to the form in which it is administered.
V1 receptors are found in various sites around the body.  The major points include the CNS, Liver, Anterior Pituitary, Muscle (both vascular and non-vascular smooth muscle), and Platelets (CLAMP).
Another example of a V1 Agonist is Terlipressin - which is used in Oesophageal Varices.
Fenetylline

# Overview
Fenethylline (BAN, USAN), also spelled phenethylline and fenetylline (INN), and also known as amphetaminoethyltheophylline and amfetyline, is a chemical linkage of amphetamine and theophylline which behaves as a prodrug to both of the aforementioned drugs. It is marketed for use as a psychostimulant under the brand names Captagon, Biocapton, and Fitton.

# History
Fenethylline was invented by Degussa AG in 1961 and used for around 25 years as a milder alternative to amphetamines. Despite no accepted FDA indication for fenethylline, it was used in applications such as treating "hyperkinetic children" (what would now be referred to as Attention Deficit Hyperactivity Disorder), and also less commonly for treating narcolepsy or as an antidepressant. One of the main advantages of fenethylline was that it does not tend to increase blood pressure to the same extent as amphetamines and so could be used in patients with cardiovascular conditions.
Fenethylline was considered to have fewer side effects and less potential for abuse than amphetamine. Nevertheless, fenethylline was listed in 1981 as a schedule I controlled substance in the US, and it became illegal in most countries in 1986 after being listed by the World Health Organization for international scheduling under the Convention on Psychotropic Substances, even though the actual incidence of fenethylline abuse was quite low.

# Pharmacology
Fenethylline is metabolized by the body to form two drugs amphetamine (24.5% of oral dose) and theophylline (13.7% of oral dose), both of which are active stimulants themselves. The physiological effects of fenethylline therefore result from a combination of all three drugs.

# Abuse
Abuse of fenethylline of the brand name Captagon is most common in Arab countries and counterfeit versions of the drug continue to be available despite its illegality.  
Many of these counterfeit "Captagon" tablets actually contain other amphetamine derivatives that are easier to produce, but are pressed and stamped to look like Captagon pills. Some counterfeit Captagon pills analyzed do contain fenethylline however, indicating that illicit production of this drug continues to take place.
Fenethylline is a popular drug, allegedly used by militant groups in Syria and Lebanon. It is manufactured locally in a cheap and simple process. According to some leaks, militant groups would also export the drug in exchange for weapons and cash.