Persius/hicric huggingface dataset:
Tropomyosin

# Overview
Tropomyosin, along with troponin, regulates the shortening of the muscle protein filaments actin and myosin. In resting muscle fibres, tropomyosin is displaced from its normal binding groove by troponin. This displaced conformation of tropomyosin prevents the binding of myosin heads, thereby inhibiting muscle contraction. Under normal stimulation to muscle fibers, Ca2+ ions are released from the sarcoplasmic reticulum of the myocytes which causes troponin to release its hold on actin, allowing tropomyosin to return to a normal conformation which allows myosin heads to walk along actin filaments and thereby facilitating muscle contraction.

# Functional Characteristics

## Sliding filament theory
Tropomyosin is an alpha helical coiled coil protein dimer that binds end to end along F actin filaments in striated muscle. Tropomyosin blocks myosin binding and hence crossbridge cycling in the absence of Ca2+ and the muscle Ca2+ regulatory element troponin. Ca2+ influx from the sarcoplasmic reticulum of striated muscle myocytes binds to troponin and subsequently moves tropomyosin on the F-actin filament exposing the myosin binding sites.
Recent structural visualization and kinetic modeling has suggested that myosin binding further moves tropomyosin on actin to a fully open state allowing for uninhibited crossbridge cycling as the muscle contracts. This three state model of thin filament regulation involving tropomyosin and troponin is still debated by experts who believe that two state regulation of muscle contraction (involving a blocked and open state) is sufficient to explain current experimental data and models.

# Allergies
Tropomyosin is a pan-allergen (an allergen widely-distributed in the nature) because it is a highly-conserved protein among species. Certain tropomyosins are known to cause allergies in certain people, and those who have cross-reactive allergies can get symptons from a range of sources due to a common allergen found in all these sources: Shrimp, dust mites and mollusks. This common allergen is the reason why some people sensitized with mite tropomyosin could have an allergic reaction after eating seafood.

# Genes
- TPM1
- TPM2
- TPM3
- TPM4

# Additional images
- Molecular mechanisms of muscular function
Tyrothricin

# Overview
Tyrothricin is a cyclic polypeptide-antibiotic mixture from Bacillus brevis. It is a locally effective antibiotic effective against gram-positive bacteria. It is sometimes combined with benzocaine 5 mg to provide relief from sore throats. In systemic intake it can lead to severe side effects, therefore, the use is limited to topical application.
Tyrothricin belongs to the pharmacologically related group of polypeptide antibiotic compounds including colistin, polymyxin B and bacitracin. There is no cross-resistance to these three agents.

# Effect
Tyrothricin inhibits protein biosynthesis of gram-positive organisms, but is completely ineffective against gram-negative.

# Application
The most common use for tyrothricin is inflammation of the throat, gastric mucosa, and angina tonsillaris. In order to use tyrothricin, the mucous membrane must be intact.  This is to ensure that tyrothricin will not come into contact with the bloodstream, therefore limiting the risk of systemic absorption.

# Side-effects
Known hypersensitivity reactions are common, temporary loss of balance (see Vestibular system) and nephrotoxic effects, i.e. impairment of renal function. There are no long term studies about its effect on pregnancy and lactation.

# Trade names
Separate preparations: Limexx (AT), Tyrosur (DE)
Compounds: Citropain (CH), Dorithricin (DE, AT), Lemocin (DE, AT, CH), Mebucaine (CH), Mebucasol (CH), Otothricinol (CH), Sangerol (CH), Solmucaine (CH), Trachisan (DE), Tyroqualin (CH) and generic (AT, CH), Tyrozets (UK)
Uranium-235
Uranium-235 is an isotope of uranium that differs from the element's other common isotope, uranium-238, by its ability to cause a rapidly expanding fission chain reaction, i.e., it is fissile. It is the only fissile isotope found in any economic quantity in nature. It was discovered in 1935  by Arthur Jeffrey Dempster.
If at least one neutron from U-235 fission strikes another nucleus and causes it to fission, then the chain reaction will continue. If the reaction will sustain itself, it is said to be critical, and the mass of U-235 required to produce the critical condition is said to be a critical mass. A critical chain reaction can be achieved at low concentrations of U-235 if the neutrons from fission are moderated to lower their speed, since the probability for fission with slow neutrons is greater. A fission chain reaction produces intermediate mass fragments which are highly radioactive and produce further energy by their radioactive decay. Some of them produce neutrons, called delayed neutrons, which contribute to the fission chain reaction. In nuclear reactors, the reaction is slowed down by the addition of control rods which are made of elements such as boron, cadmium, and hafnium which can absorb a large number of neutrons. In nuclear bombs, the reaction is uncontrolled and the large amount of energy released creates a nuclear explosion.
The fission of one atom of U-235 generates 200 MeV = 3.2  10-11 J, i.e. 18 TJ/mol = 77 TJ/kg.  However, approximately 5% of this energy is carried away by virtually undetectable neutrinos. 
The nuclear cross section for slow thermal neutrons is about 1000 barns. For fast neutrons it is in the order of 1 barn. 
Only around 0.72% of all natural uranium is uranium-235, the rest being mostly uranium-238. This concentration is insufficient for a self sustaining reaction in a light water reactor; enrichment, which just means separating out the uranium-238, must take place to get a usable concentration of uranium-235. Pressurised Heavy Water Reactors, other heavy water reactors, and some graphite moderated reactors are known for using unenriched uranium. Uranium which has been processed to boost its uranium-235 proportion is known as enriched uranium, different applications require unique levels of enrichment.
The fissile uranium in nuclear weapons usually contains 85% or more of 235U known as weapon(s)-grade, though for a crude, inefficient weapon 20% is sufficient (called weapon(s)-usable); even less is sufficient, but then the critical mass required rapidly increases. However, judicious use of implosion and neutron reflectors can enable construction of a weapon from a quantity of uranium below the usual critical mass for its level of enrichment, though this would likely only be possible in a country which already had extensive experience in developing nuclear weapons. The Little Boy atomic bomb was fueled by enriched uranium. Most modern nuclear arsenals use plutonium as the fissile component, however U-235 devices remain a nuclear proliferation concern due to the simplicity of this nuclear weapon design.
Uranium-235 has a half-life of 700 million years.
Ubiquitin C
Polyubiquitin-C is a protein encoded by the UBC gene in humans. Polyubiquitin-C is one of the sources of ubiquitin, along with UBB, UBA52, and RPS27A.
UBC gene is one of the two stress-regulated polyubiquitin genes (UBB and UBC) in mammals. It plays a key role in maintaining cellular ubiquitin levels under stress conditions. Defects of UBC gene could lead to mid-gestation embryonic lethality.

# Structure

## Gene
UBC gene is located at chromosome 12q24.3, consisting of 2 exons. The promoter of the UBC gene contains putative heat shock elements (HSEs), which mediates UBC induction upon stress. UBC gene differs from UBB gene in the number of Ub coding units they contain. Nine to ten Ub units were in the UBC gene.

## Protein
In polyubiquitin-C, the C-terminus of a given ubiquitin molecule is covalently conjugated to either the N-terminal residue or one of seven lysine residues of another ubiquitin molecule. Different linking of ubiquitin chains results in distinct conformations. There are 8 linkage types of polyubiquitin-C, and each type possesses the linkage-dependent dynamics and a linkage-specific conformation.

# Function
The diversity of polyubiquitin-C means that ubiquitylation contributes to the regulation of many cellular events. Polyubiquitin-C doesnt activate the heat-shock response, but it plays a key role in sustaining the response. UBC gene transcription is induced during stress and provides extra ubiquitin necessary to remove damaged/unfolded proteins. Polyubiquitin-C has important role in diverse biological processes, such as innate immunity, DNA repair and kinase activity. Unanchored polyubiquitin-C are also key signaling molecules that connect and coordinate the proteasome and autophagy to eliminate toxic protein aggregates.

# Clinical significance
Loss of a single UBC allele has no apparent phenotype, while homozygous deletion of UBC gene leads to mid-gestation embryonic lethality due to a defect in fetal liver development, as well as a delay in cell-cycle progression and increased susceptibility to cellular stress. It is also reported that homozygous deletion of UBC gene in mouse embryonic fibroblasts will cause decreased cellular Ub level and reduced viability under oxidative stress.

# Interactions
Polyubiquitin-C has been shown to interact with:
- BIRC2,
- BSG,
- C21orf59,
- CDC2,
- E2F1,
- EGFR,
- HDAC3,
- HIF1A,
- IRAK1,
- KIAA0753.
- MARK4,
- MDM2,
- NDUFA3,
- NFE2L2,
- NOTCH1,
- NUAK1,
- OPRK1,
- P53,
- PCNA
- PARK2,
- RIPK1,
- RPS6KB1,
- S100A10,
- SCNN1A,
- SCNN1G,
- SFPQ,
- SMAD3,
- SMURF2,
- SP1,
- TRAF6,  and
- THRA.
Uhl anomaly
Synonyms and keywords: parchment right ventricle. See also: arrhythmogenic right ventricular dysplasia

# Overview
Uhl anomaly is a very rare congenital heart disease  with a partial or total loss of the myocardial muscle in the right ventricle.

# Pathophysiology
There is a total loss of myocardial muscle in the right ventricle.  It represents a severe from of arrhythmogenic right ventricular dysplasia.

# Epidemiology and Demographics
Less than 100 cases have been reported between 19001993.

# Historical Perspective
Uhl anomaly was first described in 1952.

# Diagnosis

## Fetal echocardiographic findings
Three findings are  enlarged right ventricular cavity without apical trabeculation with a thin hypokinetic ventricular wall.

# Sources
- Leon Gerlis, Uhl's anomaly, Orphanet Encyclopedia, January 2003.
Ureterocele
For patient information page click here
Steven C. Campbell, M.D., Ph.D.

# Overview
A ureterocele is a congenital abnormality found in the urinary bladder. In this condition called ureteroceles, the distal ureter balloons at its opening into the bladder, forming a sac-like pouch. It is most often associated with a double collector system, where two ureters drain their respective kidney instead of one. Simple ureteroceles, where the condition involves only a single ureter, represents only twenty percent of cases.
Ureteroceles strikes only one in 4,000 individuals, at least four fifths of whom are female. Patients are frequently Caucasian.

# Causes
Definitive causes of ureteroceles have not been found. While the abnormal growth occurs within the uterus, it has not been substantiated that genetics are to blame.

# Signs and symptoms
The signs and symptoms of ureteroceles in the latter two forms can easily be confused with other medical conditions. Symptoms can include:
- Frequent urinary tract infection
- Urosepsis
- Obstructive voiding symptoms
- Urinary retention
- Failure to thrive
- Hematuria
- Cyclic abdominal pain
- Ureteral calculus

# Diagnosis
Since the advent of the ultrasound, most ureteroceles is diagnosed prenatally. The pediatric and adult conditions are often found only through diagnostic imaging performed for reasons other than suspicious ureteroceles.

## Imaging studies
- At US, the ureterocele is identified as a cystic intravesical mass contiguous with a dilated ureter.
- At VCUG, a collapsed simple ureterocele usually manifests as a rounded filling defect within the bladder.
- When performed, IVU will usually demonstrate a collection of contrast material within the ureterocele, which produces the classic cobra head sign consisting of a round or oval area of increased opacity surrounded by the radiolucent halo of the wall of the ureterocele.
Patient #1
Patient #2

# Complications
Many other complications arise from ureteroceles. Redundant collection systems are usually smaller in diameter than single, and predispose the patient to impassable kidney stones. The effective "bladder within a bladder" compounds this problem by increasing the collision of uric acid particles, the process by which uric acid stones are formed. Ureteroceles is also associated with poor kidney function. It can cause frequent blockage of the ureter leading to serious kidney damage. In other cases, a small, upper portion of the kidney is congenitally non-functional. Though often benign, this problem can necessitate the removal of non-functioning parts.
Urodynamics
Steven C. Campbell, M.D., Ph.D.

# Overview
Urodynamics is the investigation of functional disorders of the lower urinary tract, i.e. the bladder and the urethra. Symptoms are particularly unreliable in the study of the lower urinary tract, so the purpose of urodynamics is to confirm objectively the pathology that a person's symptoms would suggest.
So for example if a person complains of a high frequency of urination it might be because of detrusor overactivity. Urodynamics would involve the use of pressure transducers attached to catheters inside the bladder and rectum to verify such a pressure pattern.
Detrusor overactivity is characterised by the phasic pressure contractions seen in the image on the right. The red trace is the abdominal pressure usually recorded in the rectum, the blue trace is the actual bladder pressure (usually called intravesical) and the purple trace is the detrusor pressure - the part of the intravesical pressure that is entirely due to the detrusor muscle. This is not a normal finding. The normal bladder should be low pressure during filling.
Uteroglobin
Uteroglobin, also known as secretoglobin family 1A member 1 (SCGB1A1), is a protein that in humans is encoded by the SCGB1A1 gene.
SCGB1A1 is the founding member of the secretoglobin family of small, secreted, disulfide-bridged dimeric proteins found only in mammals. This antiparallel disulfide linked homodimeric protein is multifunctional and found in various tissues in various names such as: uteroglobin (UG, UGB), uteroglobin-like antigen (UGL), blastokinin, club-cell secretory protein (CCSP), Clara-cell 16 kD protein (17 in rat/mice), club-cell-specific 10 kD protein (CC10), human protein 1, urine protein 1 (UP-1), polychlorinated biphenyl-binding protein (PCB-BP), human club cell phospholipid-binding protein (hCCPBP), secretoglobin 1A member 1 (SCGB1A1).
This protein is specifically expressed in club cells in the lungs.

# Function
The precise physiological role of uteroglobin is not yet known. Putative functions are:
- Immunomodulation
- Progesterone binding: weak in some animals, especially weak in humans. (Note: UGB is itself progesterone induced gene in the endometrium in Lagomorphs)
- Inhibits phospholipase A2 in vitro
- Binds phosphatidylcholine, phosphatidylinositol
- Binds to fibronectin: The uteroglobulin knockout mice on the inbred C57Bl6 strain develop Goodpasture's syndrome like glomerulopathy due to fibronectin binding of IgA which might potentially be prevented by uteroglobin replacement. However contrary to the animal model claims, human genetic data might suggest that the effect may be indirect
- Uteroglobin knockout mice on the inbred 129 strain appear to have healthy phenotype (no glomerulopathy development), but show physiological differences in their responses to respiratory challenges. The phenotype exhibited by these mice are; decreased bioaccumulation of biphenyls, susceptibility and increased IL-13, and IL-6 following hyperoxic challenge, and changes in the club cell morphology. 
- Target of polychlorinated biphenyl (pcb) binding
VE-cadherin
Cadherin 5, type 2 or VE-cadherin (vascular endothelial cadherin) also known as CD144 (Cluster of Differentiation 144), is a type of cadherin. It is encoded by the human gene CDH5.

# Function
VE-cadherin is a classical cadherin from the cadherin superfamily and the gene is located in a six-cadherin cluster in a region on the long arm of chromosome 16 that is involved in loss of heterozygosity events in breast and prostate cancer. The encoded protein is a calcium-dependent cellcell adhesion glycoprotein composed of five extracellular cadherin repeats, a transmembrane region and a highly conserved cytoplasmic tail. Functioning as a classic cadherin by imparting to cells the ability to adhere in a homophilic manner, the protein may play an important role in endothelial cell biology through control of the cohesion and organization of the intercellular junctions.
Integrity of intercellular junctions is a major determinant of permeability of the endothelium, and the VE-cadherin-based adherens junction is thought to be particularly important.   VE-cadherin is known to be required for maintaining a restrictive endothelial barrier  early studies using blocking antibodies to VE-cadherin increased monolayer permeability in cultured cells and resulted in interstitial edema and hemorrhage in vivo. A recent study has shown that A20 (which is a dual-ubiquitin editing enzyme) is essential for stability and expression of VE-cadherin. Deubiquitinase function of A20 was shown to remove ubiquitin chains from VE-cadherin, thereby prevented loss of VE-cadherin expression at the endothelial adherens junctions. 
VE-cadherin is indispensable for proper vascular development  there have been two transgenic mouse models of VE-cadherin deficiency, both embryonic lethal due to vascular defects. Further studies using one of these models revealed that although vasculogenesis occurred, nascent vessels collapsed or disassembled in the absence of VE-cadherin. Therefore, it was concluded that VE-cadherin serves the purpose of maintaining newly formed vessels.

# Interactions
VE-cadherin has been shown to interact with:
- Beta-catenin
- Plakoglobin
- PTPRB
- Catenin (cadherin-associated protein), alpha 1
- CTNND1
- PTPmu (PTPRM)
- PTPrho (PTPRT)

# As a biomarker
VE-Cadherin may serve as a biomarker for radiation exposure.
VS ribozyme
The Varkud satellite (VS) ribozyme carries out the cleavage of a phosphodiester bond .

# Structure
The VS ribozyme is composed of 5 helices that form an H shape (helices II to VI). The first helix (I) contains the substrate cleavage site in the stem loop.

# Species Distribution
The VS ribozyme has only been found in DNA of Neurospora mitochondria.
Vaginectomy

# Overview
Vaginectomy is a medical procedure to remove all or part of the vagina. It is usually used as a treatment for vaginal cancer. Vaginectomy is also used as part of some types of female-to-male sex reassignment surgery.

# Cancer
Vaginectomy can be divided into two kinds of operations.
An operation under which the whole vagina is removed is called a radical vaginectomy. If only the upper part of the vagina is removed then the operation is called a partial vaginectomy. The doctor will decide depending the severity of the case and the affected areas.
Usually after a radical vaginoplasty a plastic surgeon will perform a vaginal reconstruction, using skin and muscle from other body parts, for aesthetic reasons.
Valinomycin
Valinomycin is a dodecadepsipeptide, that is, it is made of twelve alternating amino acids and esters to form a macrocyclic molecule.
Valinomycin is obtained from the cells of several Streptomyces strains, one of them Str. Tsusimaensis.
It is a member of the group of natural neutral ionophores because it doesn't have a residual charge. It consists of enantiomeres D-Valine and L-Valine, D-Hydroxyvaleric acid and L-Lactic acid. Structures are alternated bound via amide and ester bridges. Valinomycin is highly selective for  potassium ions over sodium ions within the cell membrane. It functions as a potassium-specific transporter and facilitates the movement of potassium ions through lipid membranes "down" an electrochemical potential gradient. The stability constant K for the potassium-valinomycin complex is 106 and for the sodium-valinomycin complex only 10. This difference is important for maintaining the selectivity of valinomycin for the transport of potassium ions (and not sodium ions) in biological systems.

# Structure
From the chemical structure it can be seen that there are some prevailing features. The 12 carbonyl groups are essential for the binding of metal ions, and also for solvatation in polar solvent. The isopropyl groups and methyl groups are responsible for solvatation in nonpolar solvents.
 Along with its shape and size this molecular duality is the main reason for its binding properties. For polar solvents valinomycin will mainly expose the carbonyls to the solvent and in nonpolar solvents the iso-propyl groups are located predominantly on the exterior of the molecule. This conformation changes when valinomycin is bound to a potassium ion. The molecule is "locked" into a conformation where the exterior is made up of the isopropyl groups. It is not actually locked into configuration because the size of the molecule makes it highly flexible, but the potassium gives some degree of coordination to the macromolecule.

# Application
Valinomycin acts as ion-exchange agent in Potassium selective electrode.
Vernakalant

# Overview
Vernakalant (INN; codenamed RSD1235, proposed tradenames Kynapid and Brinavess) is an investigational drug under regulatory review for the acute conversion of atrial fibrillation. It was initially developed by Cardiome Pharma, and the intravenous formulation has been bought for further development by Merck in April 2009.
On December 11, 2007, the Cardiovascular and Renal Drugs Advisory Committee of the US Food and Drug Administration (FDA) voted to recommend the approval of vernakalant, but in August 2008 the FDA judged that additional information was necessary for approval.
The drug was approved in Europe on September 1, 2010.
An oral formulation underwent Phase II clinical trials between 2005 and 2008.

# Mechanism of action
Like other class III antiarrhythmics, vernakalant blocks atrial potassium channels, thereby prolonging repolarization. It differs from typical class III agents by blocking a certain type of potassium channel, the cardiac transient outward potassium current, with increased potency as the heart rate increases. This means that it is more effective at high heart rates, while other class III agents tend to lose effectiveness under these circumstances. It also slightly blocks the hERG potassium channel, leading to a prolonged QT interval. This may theoretically increase the risk of ventricular tachycardia, though this does not seem to be clinically relevant.
The drug also blocks atrial sodium channels.
Victor Ling

# Overview
Dr. Victor Ling is an award-winning Canadian researcher in the field of medicine.  Ling's research focuses on drug resistance in cancer.  He is best known for his discovery of P-glycoprotein, one of the proteins responsible for multidrug resistance.
Ling was born in China, and emigrated to Canada as a child.  He received his bachelor's degree in 1966 from the University of Toronto and his PhD in 1969 from the University of British Columbia.  In 2006, he was awarded an honorary doctorate from Trinity Western University. He undertook post-doctoral training with nobel-laureate Dr. Fred Sanger at Cambridge University.  Ling is currently Assistant Dean of the Faculty of Medicine at the University of British Columbia and Vice-President, Discovery at the BC Cancer Agency in Vancouver, British Columbia.

# Honours
- 1990, awarded the Gairdner Award from the Gairdner Foundation for outstanding contributions to medical science
- 1991, awarded the Charles F. Kettering Prize
- 1991, awarded the Steiner Award, the highest honour in cancer research
- 1994, awarded the Robert L. Noble Prize by the National Cancer Institute of Canada
- 2000, appointed to the Order of British Columbia