| NA | Avogadro constant or number; nalidixic acid; Narcotics Anonymous; network administrator; neuraminida... |
|---|---|
| NAA | N-acetyl aspartate; naphthaleneacetic acid; neutral amino acid; neutron activation analysis; neutrop... |
| TCA | T-cell A locus; terminal cancer; tetracyclic antidepressant; total cholic acid; total circulating al... |
| TPA | tannic acid, polyphosphomolybdic acid, and amino acid; 12-0-tetradecanoyl-phorbol-13-acetate; third-... |
| UA | absorption unsharpness; ultra-audible; ultrasonic arteriography; umbilical artery; unauthorized abse... |
| South African type porphyria | Porphyria characterised by abdominal pain and neuropsychiatric abnormalities, by dermal sensitivity to light and mechanical trauma, by increased faecal excretion of proto-and coproporphyrin, and by increased urinary excretion of d-aminolevulinic acid, porphobilinogen, and porphyrins; due to a deficiency of protoporphyrinogen oxidase; autosomal dominant inheritance. Synonym: protocoproporphyria hereditaria, South African type porphyria. (05 Mar 2000) |
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| Naegeli type of monocytic leukaemia | A variant of granulocytic leukaemia with monocytosis in the peripheral blood. Synonym: Naegeli type of monocytic leukaemia. (05 Mar 2000) |
| name bearing type | <zoology> The type genus, type species, holotype, lectotype, series of syntypes, neotype, type slide, or hapantotype, that provides the objective standard of reference whereby the application of the name of a taxon can be determined. (09 Jan 1998) |
| neoplasms by histologic type | A collective term for the various histological types of neoplasms. It is more likely to be used by searchers than by indexers and catalogers. (12 Dec 1998) |
| stream-type fish | Fish that rear for a year or more in a stream. (09 Oct 1997) |
| Nezelof type of thymic alymphoplasia | Synonym: cellular immunodeficiency with abnormal immunoglobulin synthesis. (05 Mar 2000) |
| s-type cholinesterase | <enzyme> An enzyme that breaks down acetylcholine tostop its action. (22 May 1997) |
| S type lectin | <protein> One of two classes of lectin produced by animal cells. The classification of animal lectins into two classes, the other being the C type, was originally proposed by K.Drickamer. The carbohydrate binding activity of the S type lectins requires their cysteines to have free thiols and does not need divalent cations (c.f. C type lectins). They mostly have molecular masses in the range 14-16 kD and often form dimers and higher oligomers. The carbohydrate recognition domain contains a number of critically conserved amino acids and largely binds to _ galactosides. S type lectins certainly occur as cytoplasmic proteins but the existence of extracellular S type lectins is still a matter of debate. (18 Nov 1997) |
| nomenclatural type | The constituent element of a taxon to which the name of the taxon is permanently attached; the type of a species is preferably a strain (in special cases it may be a description, a preserved specimen or preparation, or an illustration); the type of a genus is a species; and the type of an order, family, or tribe is the genus on whose name the name of the higher taxon is based. (05 Mar 2000) |
| nutritional type cerebellar atrophy | A restricted type of cerebellar cortical degeneration, affecting particularly the Purkinje cells of the anterior and superior vermis; probably caused by thiamin deficiency; most frequently seen in chronic alcoholics and then called alcoholic cerebellar degeneration. (05 Mar 2000) |
| delayed type hypersensitivity | <immunology> Hypersensitivity (increased reaction by the body to a foreign substance such as an antigen or allergen) that does not appear until 24 to 48 hours after the body is exposed to the foreign substance. (09 Oct 1997) |
| Swiss type agammaglobulinaemia | Group of rare congenital disorders characterised by impairment of both humoral and cell-mediated immunity, leukopenia, and low or absent antibody levels. It is inherited as an x-linked or autosomal recessive defect. About half of the patients with autosomal recessive scid are deficient in the enzyme adenosine deaminase. (12 Dec 1998) |
| deoxyribonucleases, type III site-specific | <enzyme> Enzyme systems composed of two subunits and requiring ATP and magnesium for endonucleolytic activity; they do not function as atpases. They exist as complexes with modification methylases of similar specificity. The systems recognise specific short DNA sequences and cleave a short distance, about 24 to 27 bases, away from the recognition sequence to give specific double-stranded fragments with terminal 5'-phosphates. Enzymes from different microorganisms with the same specificity are called isoschizomers. Registry number: EC 3.1.21.5 (12 Dec 1998) |
| deoxyribonucleases, type II site-specific | <enzyme> Enzyme systems containing a single subunit and requiring only magnesium for endonucleolytic activity. The corresponding modification methylases are separate enzymes. The systems recognise specific short DNA sequences and cleave either within, or at a short specific distance from, the recognition sequence to give specific double-stranded fragments with terminal 5'-phosphates. Enzymes from different microorganisms with the same specificity are called isoschizomers. Registry number: EC 3.1.21.4 (12 Dec 1998) |
| deoxyribonucleases, type I site-specific | <enzyme> Enzyme systems containing three different subunits and requiring ATP, s-adenosylmethionine, and magnesium for endonucleolytic activity to give random double-stranded fragments with terminal 5'-phosphates. They function also as DNA-dependent atpases and modification methylases, catalyzing the reactions of EC 2.1.1.72 and EC 2.1.1.73 with similar site-specificity. The systems recognise specific short DNA sequences and cleave at sites remote from the recognition sequence. Enzymes from different microorganisms with the same specificity are called isoschizomers. Registry number: EC 3.1.21.3 (12 Dec 1998) |