| gamma alcoholism | Jellinek's term for a severe stage of alcoholism characterised by a progression from psychological to physiological dependence upon alcohol, including tissue dependence and withdrawal symptoms, with loss of control over alcohol intake and destructive effects on interpersonal relationships. (05 Mar 2000) |
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| gamma aminobutyric acid | <biochemistry> An important amino acid which functions as the most prevalent inhibitory neurotransmitter in the central nervous system. Gamma aminobutyric acid works in partnership with a derivative of Vitamin B-6, pyridoxine, to cross from the axons to the dendrites through the synaptic cleft, in response to an electrical signal in the neuron and inhibits message transmission. This helps control the nerve cells from firing too fast, which would overload the system. The action of gamma aminobutyric acid decreases epileptic seizures and muscle spasms by inhibiting electrical signals in this manner. Studies have shown that the site of action in the brain of benzodiazepams, including Valium, is directly coupled to the brain receptor for gamma aminobutyric acid. Acronym: GABA (05 Jan 1998) |
| gamma-amylase | A hydrolase removing terminal alpha-1,4-linked d-glucose residues from nonreducing ends of chains, with release of beta-d-glucose. Synonym: acid maltase, amyloglucosidase, gamma-amylase, glucoamylase. (05 Mar 2000) |
| gamma angle | <ophthalmology> The angle formed between a line joining the fixation point to the centre of the eye and the optic axis. (05 Mar 2000) |
| gamma-anticollagenase | <chemical> Serum protease inhibitor (26 Jun 1999) |
| gamma benzene hexachloride | <chemical> One of the purified isomers of hexachlorobenzene which is used as a scabicide and pediculicide applied topically to the skin in various lotions, creams, and shampoos; gamma benzene hexachloride can be absorbed through the skin. Resembles DDT in its actions but is less persistent. Incorrect name for 1,2,3,4,5,6-hexachlorocyclohexane (lindane). Synonym: hexachlorocyclohexane. Acronym: GBH (05 Mar 2000) |
| gamma-butyrobetaine | Gamma-(Trimethylammonium) butyric acid;a betaine of gamma-aminobutyric acid; a precursor of carnitine by hydroxylation of the beta-carbon. (05 Mar 2000) |
| gamma camera | Any one of several scintigraphic cameras that records simultaneously counts from the entire operative field of view. Synonym: scintillation camera. (05 Mar 2000) |
| gamma cameras | Electronic instruments that produce photographs or cathode-ray tube images of the gamma-ray emissions from organs containing radionuclide tracers. (12 Dec 1998) |
| gamma cell of pancreas | A cell of the pancreatic islets of the guinea pig. Synonym: gamma cell of pancreas. Synonym: parafollicular cells. (05 Mar 2000) |
| gamma crystallin | The least rapidly mobile form of crystallin on electrophoresis. (05 Mar 2000) |
| gamma-cyanoaminobutyrate synthase | <enzyme> Homocystine + 2cn- yields gamma-cyanobutyric acid + scn-+ homocysteine; pyridoxal-5-phosphate dependent Registry number: EC 4.- (26 Jun 1999) |
| gamma-cystathionase | <enzyme> A multifunctional pyridoxal phosphate enzyme. In the final step in the biosynthesis of cysteine it catalyses the cleavage of cystathionine to yield cysteine, ammonia, and 2-ketobutyrate. Chemical name: L-Cystathionine cysteine-lyase (deaminating) Registry number: EC 4.4.1.1 (12 Dec 1998) |
| gamma efferent | The thin axon of a gamma motor neuron innervating the intrafusal muscle fibres of a muscle spindle. (05 Mar 2000) |
| gamma emission | <physics> Nuclear decay process whereby the nucleus goes from an excited state to a more stable state by emitting a gamma ray. See: gamma ray. (09 Oct 1997) |