Persius/hicric huggingface dataset:
Ceramide synthase 1
Ceramide synthase 1 also known as LAG1 longevity assurance homolog 1 is an enzyme that in humans is encoded by the CERS1 gene.

# Function
This gene encodes a member of the bone morphogenetic protein (BMP) family and the TGF-beta superfamily. This group of proteins is characterized by a polybasic proteolytic processing site that is cleaved to produce a mature protein containing seven conserved cysteine residues. Members of this family are regulators of cell growth and differentiation in both embryonic and adult tissues. Studies in yeast suggest that the encoded protein is involved in aging. This protein is transcribed from a monocistronic mRNA as well as a bicistronic mRNA, which also encodes growth differentiation factor 1.
Ceramide synthase 1 (CerS1) is a ceramide synthase that catalyzes the synthesis of C18 ceramide in a fumonisin B1-independent manner, and is primarily expressed in the brain. It can also be found in low levels in skeletal muscle and the testis.
Within the cell, CerS1 is located in the endoplasmic reticulum (ER) and golgi apparatus membrane. CerS1 has two isoforms and isoform 1 may recycle from the golgi to the ER.
CerS1/GDF1 mRNA is strongly expressed in muscle and brain, and was also found in heart and lung. Within the brain, CerS1 is the primary CerS expressed in most neurons. In white matter, it can only be found in low levels.
In a recent experiment performed in mice in 2012, ablation of neuronal CerS1 decreased levels of sphingolipids, hexosylceramides, and sphingomyelin. Although the brains in these mice appeared to develop normally, researchers observed atrophy of the cerebellum, and Purkinje neurons appeared to degenerate. Granule cells also showed a 6 times increased rate of apoptosis. Behaviorally, the mice expressed motor and neurophysiological impairment.

# Structure
Unlike other mammalian ceramides, CerS1 does not appear to have a Hox-like domain. It is functionally and structurally distinct from other CerS and is found in an entirely different branch of the phylogenetic tree.

# Clinical significance
On application of various stresses, CerS1 turns over rapidly by ubiquitination and proteasomal degradation, suggesting that it has a short half life.
It has been suggested that CerS1 is involved with the regulation of the growth of head and neck squamous cell carcinoma (HNSCC), based on the information that C18 ceramide levels are lower in HNSCC tissues than in normal tissue. CerS1, in particular amongst other CerS, has also been shown to sensitize cells to chemotherapeutic drugs, such as cisplatin, carboplatin, doxorubicin, and vincristine.
Ceramide synthase 2
Ceramide synthase 2, also known as LAG1 longevity assurance homolog 2 or Tumor metastasis-suppressor gene 1 protein is an enzyme that in humans is encoded by the CERS2 gene.
Ceramide synthase 2 is a ceramide synthase that catalyses the synthesis of very long acyl chain ceramides, including C20 and C26 ceramides. It is the most ubiquitously expressed of all CerS and has the broadest distribution in the human body.
CerS2 was first identified in 2001. It contains the conserved TLC domain and Hox-like domain common to almost all CerS.

# Distribution
CerS2 mRNA (TRH3) has been found in most tissues and it is strongly expressed in liver, intestine and brain. CerS2 is much more widely distributed than Ceramide synthase 1 (CerS1) and is found in at least 12 tissues in the human body, with high expression in the kidney and liver, and moderate expression in the brain and other organs. In the mouse brain, CerS2 is mainly expressed white matter tracts, specifically in oligodendrocytes and Schwann cells.

# Function
Expression of CerS2 is transiently increased during periods of active myelination, suggesting that it is important for the synthesis of myelin sphingolipids. The lack of CerS2, as shown in knockout mice, induces the autophagy and activation of the unfolded protein response (UPR). These mice showed no decrease in overall ceramide level, but levels of sphinganine were elevated. They also developed severe liver disease, but there was no observable change in the kidneys.
The CerS2 gene is compact in size and is located in a chromosomal region that is replicated early in the cell cycle. CerS2 activity is regulated by sphingosine-1-phosphate (S1P) via two sphingosine-1-phosphate receptor-like residues on CerS2 that operate independently.

# Pathological significance
CerS2 levels are significantly elevated in breast cancer tissue compared to normal tissue, along with increased levels of ceramide synthase 6 (CerS6).
CerS2 was also implicated in the control of body weight. The administration of leptin to rats induced a decrease in CerS2 was observed in white adipose tissue.
Ceramide synthase 3
Ceramide synthase 3 (CersS3), also known as longevity assurance homologue 3, is an enzyme that is encoded in humans by the CERS3 gene.

# Function
CerS3 synthesizes C24-ceramides and ceramides with longer acyl chains, and is found mainly in skin and testis. Specifically, CerS3 synthesizes ceramides containing -hydroxy (2-hydroxy) fatty acids, which are abundant in skin tissue, where they help maintain the water permeability barrier qualities of the skin. It is found in large quantities in keratinocytes, and this increases during keratinocyte differentiation.
In the testes, CerS3 is involved in sperm formation and androgen production. Cers3 gene expression is located within germ cells, where it is massively upregulated during juvenile testicular maturation. This upregulation is correlated with increase in levels of glycosphingolipids containing very long chain (C26-C32) polyunsaturated fatty acid (LC-PUFA), which are required for spermatogenesis.

# Tissue and cellular distribution
CerS3 (T3l) mRNA is strongly expressed in skin, and was also found in brain, lung and kidney. CerS3 is mainly found in the skin and testes. CerS3 is not detectable in the brain or the sciatic nerve. Like other ceramide synthases, CerS3 is found in the endoplasmic reticulum within the cell.

# Structure
CerS3 has a molecular mass of 46.2 kDa, 383 amino acids, and six transmembrane domains. Like other ceramide synthases, CerS3 contains a Hox-like domain. CerS3 is the only ceramide synthase for which splice variants have not been reported.
Ceramide synthase 4
Ceramide synthase 4 (CerS4) is an enzyme that in humans is encoded by the CERS4 gene and is one of the least studied of the ceramide synthases.

# Function and distribution
CerS4 synthesizes ceramides containing C18-22 fatty acids in a fumonisin B1-independent manner. It is expressed at highest levels in skin, leukocytes, heart and liver, although at much lower levels than other ceramide synthases.

# Tissue and cellular distribution
CerS4 (TRH1) mRNA was found in all tissues and is strongly expressed in skin and muscle

# Clinical significance
In a 2009 study of breast cancer, total ceramide synthase levels were increased in malignant tissue, and CerS4 was one of three ceramide synthases to show an increase in mRNA levels. A significant correlation was found between CerS4 and CerS2/CerS6 expression. Unlike CerS1 and CerS5, CerS4 does not sensitize cells to chemotherapeutic drugs.
CerS4 may also be involved in the control of body weight and food intake. Upon administration of leptin, a decrease in ceramide levels was observed in rat white adipose tissue, as were expression levels of a number of genes in the sphingolipid metabolic pathway, including CerS2 and CerS4.
CerS4 expression was also found to be elevated in the brain of an Alzheimer's disease mouse model.
Ceramide synthase 5
Ceramide synthase 5 (CerS5) is the enzyme encoded in humans by the CERS5 gene.

# Function
CerS5 robustly synthesizes C16-ceramide, which is often considered to be an important pro-apoptotic ceramide. De novo ceramide synthesis is an essential trigger for Bax activation in hypoxia/reoxygenation. Following hypoxia/reoxygenation, CerS5 expression is elevated. Upon knocking down acid sphingomyelinase and CerS5 in NTERA-2 cells, Bax localization to mitochondria was reduced, indicating the importance of CerS5 activity in the apoptosis pathway.

# Tissue distribution
CerS5 (TRH4) mRNA is found in all tissues and is strongly expressed in muscle and brain. CerS5 is the major ceramide synthase detected in lung epithelia. Knock-down research in respiratory epithelium using CerS5 siRNA or fumonisin B1 reduced total CerS activity by 45% or 78%, respectively, indicating that CerS5 indeed contributes significantly to ceramide synthesis in lung. In the brain, CerS5 mRNA is detected in most cells within the gray and white matter tissues.

# Clinical significance
CerS5 sensitizes cells to the chemotherapeutic drugs doxorubicin and vincristine, but not to cisplatin or carboplatin.
A splice variant of CerS5 is expressed in lymphoma and other tumor cells and contribute to tumor recognition by the immune system. In response to upregulation of tumor suppressor protein p53, C16-ceramide levels were increased in leukemia and colon cancer cells, as were levels of CerS5 mRNA in the leukemia cells, but not in the colon cancer cells. For this reason, CerS5 looks like a promising target for the regulation of cancer and of cell death pathways.
Cerebral blood flow
Cerebral blood flow, or CBF, is the blood supply to the brain in a given time. In an adult, CBF is 750 mls/min or 15% of the cardiac output. On a weight basis, this is 50 to 54 milllitres/100grams/minute.
CBF is equal to the cerebral perfusion pressure (CPP) divided by the cerebrovascular resistance (CVR):
Control of CBF is considered in terms of the factors affecting CPP and the factors affecting CVR.
Control of the CVR is by four major mechanisms:
- Metabolic control (or 'metabolic autoregulation')
- Pressure autoregulation
- Chemical control (by arterial pCO2 and pO2)
- Neural control
CBF is tightly regulated to meet the brain's metabolic demands, and on the average must be maintained at a flow of 50 milliliters of blood per 100 grams of brain tissue per minute in adult humans.  It is important to maintain CBF within narrow limits because too much blood can raise intracranial pressure (ICP), which can compress and damage delicate brain tissue, and too little blood causes ischemia, or inadequate blood supply. Ischemia results if blood flow to the brain is below 18 to 20 ml per 100 g per minute, and tissue death occurs if flow dips below 8 to 10 ml per 100 g per minute. In brain tissue, a biochemical cascade known as the ischemic cascade is triggered when the tissue becomes ischemic, potentially resulting in damage to and death of brain cells. Medical professionals must take steps to maintain proper CBF in patients with conditions like shock, stroke, and traumatic brain injury. Cerebral blood flow in excess of 55 to 60 ml per 100 g per minute, called hyperemia, is more than the brain needs and can contribute to an increase in intracranial pressure.
Cerebral blood flow is determined by a number of factors, such as viscosity of blood, how dilated blood vessels are, and the net pressure of the flow of blood into the brain, known as cerebral perfusion pressure, which is determined by the body's blood pressure and intracranial pressure. Cerebral blood vessels are able to change the flow of blood through them by altering their diameters in a process called autoregulation; they constrict when systemic blood pressure is raised and dilate when it is lowered Arterioles also constrict and dilate in response to different chemical concentrations. For example, they dilate in response to higher levels of carbon dioxide in the blood.
Functional magnetic resonance imaging and positron emission tomography are neuroimaging techniques that can both be used to measure CBF. These techniques are also used to measure regional CBF (rCBF) within a specific brain region.
Choroid plexus cyst
The brain contains pockets or spaces called ventricles with a spongy layer of cells and blood vessels called the choroid plexus.  This is in the middle of the fetal brain.  The choroid plexus has the important function of producing a fluid called cerebrospinal fluid. The fluid produced by the cells of the choroid plexus fills the ventricles and then flows around the brain and the spinal cord to provide a cushion of fluid around these structures.
Choroid plexus cysts (CPCs) occur within this structure and come from fluid trapped within this spongy layer of cells, much like a soap bubble or a blister.  CPCs are often called "soft signs" or fetal ultrasound "markers" because some studies have found a weak association between CPCs and fetal chromosome abnormalities.
It is believed that many adults have one or more tiny CPCs. CPCs have no impact on an individual's health or development or learning.  The fetal brain may create these cysts as a normal part of development. They are temporary and usually are gone by the 32nd week of pregnancy.

# Chromosome problems
Genetic counseling is often recommended to provide more information about fetal CPCs,  to answer questions and concerns, and to outline available options such as amniocentesis. There is a possible association between ultrasound-detected fetal CPCs and chromosome problems in the baby. Types of chromosome problems that are occasionally seen include Trisomy 18 or Trisomy 21 (Down syndrome).
Generally the risks are low if there are no other risk factors. Some studies have estimated up to a 1% (1/100) chance of delivering a baby with a chromosome problem when there is a CPC present.
Other factors which may have a bearing on the baby's chances of developing chromosome problems include:
- mother's age at the expected date of delivery
- the results of serum screening; XAFP triple testing or quad screening
- evidence of other "fetal findings" seen at the time of the ultrasound that may suggest a chromosome problem
Many babies with chromosome problems do not show any signs on ultrasound.
Cetirizine overdose

# Overdosage topics
Adult Manifestations
Adolescent Manifestations
Treatment

## Adult Manifestations
In adult patients who took 150 mg of cetirizine,manifestations of somnolent but not any other clinical signs or abnormal blood chemistry or hematology results were observed
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## Adolescent Manifestations
In 18-month-old pediatric patients who took an overdose of cetirizine(approximately 180 mg), restlessness and irritability were observed initially, fallowed by drowsiness.
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## Treatment
Should overdose occur, treatment should be symptomatic or supportive, taking into account
any concomitantly ingested medications. There is no known specific antidote to cetirizine. Cetirizine is not effectively removed by dialysis, and dialysis will be ineffective unless a dialyzable agent has been concomitantly ingested.
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Adapted from the FDA Package Insert.
Cetrimonium bromide
Cetrimonium bromide ((C16H33)N(CH3)3Br) is one of the components of the topical antiseptic cetrimide.  The cetrimonium (or hexadecyltrimethylammmonium) cation is an effective antiseptic agent against bacteria and fungi.
It is a cationic surfactant. Its uses include providing a buffer solution for the extraction of DNA. It is also widely used in hair conditioning products.
As any surfactant, it forms micelles in aqueous solutions. At 303 K (30 C) it forms micelles with aggregation number 75-120 (depending on method of determination, usually avg. ~95) and degree of ionization  (fractional charge) 0.2 - 0.1 (from low to high concentration).
Standard constant of Br- counterion binding to the micelle at 303 K (30 C), calculated from Br- and CTA+ ion selective electrode measurements and conductometry data by using literature data for micelle size (r = ~3 nm), extrapolated to the critical micelle concentration is K  400 (it varies with total surfactant concentration so it is extrapolated to the point at which the concentration of micelles is zero).
The closely related compounds cetrimonium chloride and cetrimonium stearate are also used as topic antiseptics, and may be found in many household products such as shampoos and cosmetics.
Chemical Revolution
The Chemical Revolution, also called the first chemical revolution, denotes the reformulation of chemistry based on the Law of Conservation of Matter and the oxygen theory of combustion. It was  centered on the work of French chemist Antoine Lavoisier (the "father of modern chemistry").  On February 20, 1773, Lavoisier wrote: "the importance of the end in view prompted me to undertake all this work, which seemed to me destined to bring about a revolution in . . . chemistry. An immense series of experiments remains to be made." When he wrote these words in his laboratory notebook, he stood poised to change forever the practice and concepts of chemistry.
Several factors led to this revolution, such as proof that air was not an element but was composed of seven different gases. Chemists such as Henry Cavendish and Joseph Priestley performed important experiments to prove these facts. Lavoisier also translated chemistry's archaic and technical jargon into language more accessible by the largely uneducated masses.  This led to increased public interest in learning and practicing chemistry. When describing the task of reinventing chemical nomenclature, Lavoisier states:
The revolution started with the 1789 publication of Lavoisier's Traite Elementaire de Chimie (Elements of Chemistry).  Beginning with this publication and others to follow, Lavoisier discovered the composition of air and water and coined the term "oxygen". He also explained the theory of combustion, and did away with the phlogiston theory with his views on caloric.  The Traite incorporates notions of a "new chemistry" and describes the experiments and reasoning that led to Lavoisier's conclusions.  In sum, Lavoisier's Traite did for chemistry what Newton's Principia did for physics.
Additionally, Lavoisiers contemporary Jons Jakob Berzelius came up with a simplified shorthand to describe chemical compounds based on John Dalton's theory of atomic weights .
In the chemical revolution, modern chemists disproved facts that had been theorized by the Ancient Greeks and accepted ever since. For example, chemists began to denote that all structures were composed of more than four elements.
Physical dependence

# Overview
Physical dependence (or drug dependence) refers to a state resulting from habitual use of a drug, where negative physical withdrawal symptoms result from abrupt discontinuation. From the point of view of the dependent person, "dependence is duress," argues addiction researcher Griffith Edwards.

# Symptoms
Increased heart rate and/or blood pressure, sweating, and tremors are common signs of withdrawal.  More serious symptoms such as confusion, seizures, and visual hallucinations indicate a serious emergency and the need for immediate medical care. Alcohol, benzodiazepines, and barbiturates are the only commonly abused substances that can be fatal in withdrawal. Abrupt withdrawal from other drugs, such as opioids or psychostimulants, can exaggerate mild to moderate neurotoxic side effects due to hyperthermia and generation of free radicals, but life-threatening complications are very rare.

# Treatment
Treatment for physical dependence depends upon the drug being withdrawn and often includes administration of another drug, especially for substances that can be dangerous when abruptly discontinued. Treatment usually requires the initiation and then tapering of a medication that has a similar action in the brain but a longer half-life.

# Difference from Addiction
Physical dependence is different from drug addiction. The latter is often characterized by a psychological need for a drug, while the former can often be the result of legal, long-term use of medicine.

# Drugs that cause physical dependence
- barbiturates
- benzodiazepines
- ethyl alcohol (alcoholic beverage)
- GHB
- methaqualone (Quaalude)
- nicotine
- opioids
- amphetamines
Chemical ionization
Chemical ionization (CI) is an ionization technique  used in mass spectrometry.
With chemical ionization, the ions produced have little excess energy which results in less fragmentation than electron ionization.  With CI, the spectra generated show relatively little fragmentation, and an easily identifiable molecular ion.

# How it works
In a CI experiment, ions are produced through the collision of the analyte with ions of a reagent gas that are present in the ion source.  Some common reagent gases include:  methane, ammonia, and isobutane.  Inside the ion source, the reagent gas is present in large excess compared to the analyte.  Electrons entering the source will preferentially ionize the reagent gas.  The resultant collisions with other reagent gas molecules will create an ionization plasma.  Positive and negative ions of the analyte are formed by reactions with this plasma.

## Primary Ion Formation:

## Secondary Reagent Ions:

## Product Ion Formation:

# Variations

## Gas Phase Chemical Ionization
Chemical ionization for gas phase analysis is either positive or negative.

### Negative Chemical Ionization
Because not all analytes are capable of producing negative ions, a certain degree of selectivity can be gained when analyzing  compounds with acidic groups or electronegative elements.  This is especially useful for the analysis of mixtures.

### Positive Chemical Ionization
Almost all neutral analytes can form positive ions through the reactions described above.

## Liquid Phase Chemical Ionization
- Chemical ionization in an atmospheric pressure electric discharge is called atmospheric pressure chemical ionization.
Chest physiotherapy
Chest physiotherapy (CPT) is a broad, non-specific term used to describe treatments generally performed by respiratory therapists whereby breathing is improved by the indirect removal of mucus from the breathing passages of a patient.  Other terms used in Australia include respiratory or cardiothoracic physiotherapy.
Techniques include clapping or percussion: the therapist lightly claps the patient's chest, back, and area under the arms.  Percussion, while effective in the treatment of infants and children, is no longer extensively used in Australia in adults due to the introduction of more effective and self-management focussed treatments.  These include, but are not limited to, the use of "flutter" or oscillating positive pressure devices, PEP masks or devices (positive expiratory pressure) as well as specific exercise regimes.  The exercises prescribed can include specific respiratory exercises eg autogenic drainage, as well as general cardiovascular exercises which assists the body to remove sputum as well as to improve the efficiency of oxygen up-take in muscles.
In Australia, the use of the word 'physiotherapy' may be used to describe a treatment administered only by a registered physiotherapist.