| MRT | magnetic resonance tomography; maximum relaxation time; median range score; median reaction time; me... |
|---|---|
| OCR | oculocardiac reflex; oculocerebrorenal [syndrome]; optical character recognition |
| PDRT | Portland Digit Recognition |
| PRA | panel-reactive antibody; phosphoribosylamine; physician recognition award; plasma renin activity; pr... |
| PRF | partial reinforcement; patient report form; perforin; plasma recognition factor; pontine reticular f... |
| debranching factors | Enzyme's that bring about destruction of branches in glycogen; formerly considered to be one enzyme, now known to be a mixture of transferases (4-alpha-d-glucanotransferase) and hydrolases (amylo-1,6-glucosidase). Synonym: debranching factors. (05 Mar 2000) |
|---|---|
| suppressor factors, immunologic | Proteins, protein complexes, or glycoproteins secreted by suppressor T-cells that inhibit either subsequent T-cells, B-cells, or other immunologic phenomena. Some of these factors have both histocompatibility (I-j) and antigen-specific domains which may be linked by disulfide bridges. They can be elicited by haptens or other antigens and may be mass-produced by hybridomas or monoclones in the laboratory. (12 Dec 1998) |
| direct lytic factors | most abundant proteins in cobra (naja of the elapids) venom; basic polypeptides of 57 to 62 amino acids with four disulfide bonds and a molecular weight of less than 7000; causes skeletal and cardiac muscle contracture, interferes with neuromuscular and ganglionic transmission, depolarises nerve, muscle and blood cell membranes, thus causing haemolysis. Synonym: cobramine a; cobramine b; cobra cytotoxin; gamma toxin; membrane-active polypeptide. (12 Dec 1998) |
| immunologic and biological factors | A collective grouping for biologically active substances that play a role in the functioning of the immune system and those that show biological or physiological activity. (12 Dec 1998) |
| immunologic factors | Biologically active substances whose activities affect or play a role in the functioning of the immune system. (12 Dec 1998) |
| initiation factors | The set of catalytic proteins required, in addition to mRNA and ribosomes, for protein synthesis to begin. In bacteria three distinct proteins have been identified: if 1 (8 kD), IF 2 (75 kD) and IF 3 (30 kD). at least 6-8 proteins have been identified in eukaryotes. IFs 1 and 2 enhance the binding of initiator tRNA to the initiation complex. (18 Nov 1997) |
| insulin-like growth factors | Peptides whose formation is stimulated by growth hormone. These peptides bring about peripheral tissue effects of that hormone and have high (about 70%) homology to human insulin. Synonym: somatomedins. (05 Mar 2000) |
| ischemia-modifying factors | Various factors that play a role in determining the extent of necrosis with cerebral stroke; these include blood viscosity and osmolality, the blood pressure, and the anatomy of the neck and intracranial arteries. (05 Mar 2000) |
| oesophageal carcinoma risk factors | <radiology> P Plummer-Vinson Web, A achalasia, alcohol, B Barrett oesophagus, S stricture, T tylosis, tobacco see: oesophageal carcinoma (12 Dec 1998) |
| thyroid carcinoma risk factors | <radiology> Increased risk of malignancy: young female, male, history of radiation to head or neck, hard lesion, other neck masses, no shrinkage on TSH, family hx of thyroid carcinoma see: thyroid carcinoma (12 Dec 1998) |
| time factors | Elements of limited time intervals, contributing to particular results or situations. (12 Dec 1998) |
| transcription factors | Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process. (12 Dec 1998) |
| transcription factors, tfii | The so-called general transcription factors that bind to RNA polymerase II and that are required to initiate transcription. They include tfiia, tfiib, tfiid, tfiie, tfiif, tfiih, tfii-I, and tfiij. In vivo they apparently bind in an ordered multi-step process and/or may form a large preinitiation complex called RNA polymerase II holoenzyme. (12 Dec 1998) |
| transcription factors, tfiii | Factors that bind to RNA polymerase III and aid in transcription. They include the assembly factors tfiiia and tfiiic and the initiation factor tfiiib. All combine to form a preinitiation complex at the promotor that directs the binding of RNA polymerase III. (12 Dec 1998) |
| transforming growth factors | <chemical> Hormonally active polypeptides that can induce the transformed phenotype when added to normal, non-transformed cells. They have been found in culture fluids from retrovirally transformed cells and in tumour-derived cells as well as in non-neoplastic sources. Their transforming activities are due to the simultaneous action of two otherwise unrelated factors, transforming growth factor alpha and transforming growth factor beta. Chemical name: Animal growth regulators, transforming growth factors (12 Dec 1998) |