| LOC | laxative of choice; level of consciousness; liquid organic compound; locus of control; loss of consc... |
|---|---|
| MHLC | Multidimensional Health Locus of Control |
| TCA | T-cell A locus; terminal cancer; tetracyclic antidepressant; total cholic acid; total circulating al... |
| TPL | third party liability; titanium proximal loading; tumor progression locus; tyrosine phenol-lyase |
| AGA | accelerated growth area; allergic granulomatosis and angiitis; American Gastroenterological Associat... |
| locus minoris resistentiae | A place of less resistance, in latin. For example, a damaged heart valve may act as a locus minoris resistentiae where bacteria released into the blood stream (bacteraemia) tend to settle. (12 Dec 1998) |
|---|---|
| locus niger | A large cell mass, crescentic on transverse section, extending forward over the dorsal surface of the crus cerebri from the rostral border of the pons into the subthalamic region; it is composed of a dorsal stratum of closely spaced pigmented (i.e., melanin-containing) cells, the pars compacta, and a larger ventral region of widely scattered cells, the pars reticulata; the pars compacta in particular includes numerous cells that project forward to the striatum (caudate nucleus and putamen) and contain dopamine, which acts as the transmitter substance at their synaptic endings; other, apparently non-dopaminergic cells of the substantia nigra project to a rostral part of the ventral nucleus of thalmus, the middle layers of the superior colliculus and to restricted parts of the reticular formation of the midbrain; the nigrostriatal projection is reciprocated by a massive striatonigral fibre system with multiple neurotransmitters, chief among which is gamma-aminobutyric acid (GABA); substantia n. Receives smaller afferent projections from the subthalamic nucleus, the lateral segment of the globus pallidus, the dorsal nucleus of the raphe and the pedunculopontine nucleus of the midbrain. The pars reticulata forms part of the output system for the striate body. The substantia n. Is involved in the metabolic disturbances associated with Parkinson's disease and Huntington's disease. Synonym: locus niger, nucleus niger, Soemmerring's ganglion. (05 Mar 2000) |
| locus of control | A theoretical construct designed to assess a person's perceived control over his/her own behaviour; classified as internal if the person feels in control of events, external if others are perceived to have that control. (05 Mar 2000) |
| locus perforatus anticus | A region at the base of the brain through which numerous small branches of the anterior and middle cerebral arteries (lenticulostriate arteries) enter the depth of the cerebral hemisphere; it is bordered medially by the optic chasm and anterior half of the optic tract, rostrally and laterally by the lateral olfactory stria; its anteromedial part corresponds to the olfactory tubercle. Synonym: substantia perforata anterior, locus perforatus anticus, olfactory area. (05 Mar 2000) |
| locus perforatus posticus | The bottom of the interpeduncular fossa at the base of the midbrain, extending from the anterior border of the pons forward to the mamillary bodies, and containing numerous openings for the passage of perforating branches of the posterior cerebral arteries. Synonym: substantia perforata posterior, locus perforatus posticus, Malacarne's space. (05 Mar 2000) |
| genetic | <biology> Pertaining to reproduction or to birth or origin. (07 May 1998) |
| genetic amplification | A process for producing an increase in pertinent genetic material, particularly for increasing the proportion of plasmid DNA to that of bacterial DNA. Includes the production of extrachromosomal copies of the genes for RNA. (05 Mar 2000) |
| genetic assimilation | <genetics> A situation in which a characteristic that is normally expressed only in certain environmental situations becomes fixed in a population so that it no longer requires environmental factors to be expressed. (07 May 1998) |
| genetic association | The occurrence together in a population, more often than can be readily explained by chance, of two or more traits of which at least one is known to be genetic. (05 Mar 2000) |
| genetic block | <biochemistry, molecular biology> An obstruction in a biochemical pathway caused by a mutation that has crippled production of an enzyme critical to the pathway. (07 May 1998) |
| genetic burden | The genetic debt due to harmful mutation but as yet undischarged. (In a large population of fixed size every mutation with diminished genetic fitness will eventually become extinct and depending on the details of inheritance and phenotype must be paid for by a fixed number of genetic deaths per mutation, the genetic debt.) (05 Mar 2000) |
| genetic carrier | An unaffected heterozygote bearing a usually harmful recessive gene, a cancer that bears a dominant but latent age-dependent trait to have offspring with unbalanced karyotypes. (05 Mar 2000) |
| genetic code | <molecular biology> Relationship between the sequence of bases in nucleic acid and the order of amino acids in the polypeptide synthesised from it. A sequence of three nucleic acid bases (a triplet) acts as a codeword (codon) for one amino acid. (18 Nov 1997) |
| genetic colonisation | <molecular biology> The process of a parasite (such as a virus) inserting genes into a host's genome which cause the host cell to synthesise products that are only useful to the parasite. (07 May 1998) |
| genetic complement | <biology, genetics> The set of chromosomes contained within any one particular cell. (07 May 1998) |