| GA | Gamblers Anonymous; gastric analysis; gastric antrum; general anesthesia; general angiography; gener... |
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| GCAP | germ-cell alkaline phosphatase |
| GCT | general care and treatment; germ-cell tumor; giant cell thyroiditis; giant cell tumor |
| GF | gastric fistula; gastric fluid; germ-free; glass factor; glomerular filtration; gluten-free; grandfa... |
| GW | germ warfare; gigawatt; glycerin in water; gradual withdrawal; group work |
| Hill's phenomenon | <clinical sign> In aortic insufficiency, greater systolic blood pressure in the legs than in the arms; normal arterial systolic pressure in the leg is 10 to 20 mm of Hg above that in the arm, whereas in aortic insufficiency the difference may be 60 to 100 mm of Hg. Synonym: Hill's phenomenon. (05 Mar 2000) |
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| Hill's sign | <clinical sign> In aortic insufficiency, greater systolic blood pressure in the legs than in the arms; normal arterial systolic pressure in the leg is 10 to 20 mm of Hg above that in the arm, whereas in aortic insufficiency the difference may be 60 to 100 mm of Hg. Synonym: Hill's phenomenon. (05 Mar 2000) |
| germ | 1. <biology> That which is to develop a new individual; as, the germ of a foetus, of a plant or flower, and the like; the earliest form under which an organism appears. "In the entire process in which a new being originates . Two distinct classes of action participate; namely, the act of generation by which the germ is produced; and the act of development, by which that germ is evolved into the complete organism." (Carpenter) 2. That from which anything springs; origin; first principle; as, the germ of civil liberty. <biology> Disease germ, the theory that living organisms can be produced only by the evolution or development of living germs or seeds. See Biogenesis, and Abiogenesis. As applied to the origin of disease, the theory claims that the zymotic diseases are due to the rapid development and multiplication of various bacteria, the germs or spores of which are either contained in the organism itself, or transferred through the air or water. See Fermentation theory. Origin: F. Germe, fr. L. Germen, germinis, sprout, but, germ. Cf. Germen, Germane. Source: Websters Dictionary (01 Mar 1998) |
| germ cell | Cell specialised to produce haploid gametes. The germ cell line is often formed very early in embryonic development. (18 Nov 1997) |
| germ cells | The reproductive cells in multicellular organisms. (12 Dec 1998) |
| germ cell tumour | A type of brain tumour. (12 Dec 1998) |
| germ-free animal | An animal which has no microorganisms whatsoever living in or on it. An animal which was born and raised in an isolated environment with no microorganisms in it, such as within a germ-free isolator. (09 Oct 1997) |
| germ-free isolator | A chamber which has absolutely no microorganisms whatsoever living in it, where a germ-free animal can be born and raised. An artificial barrier surrounding a living facility for germ-free animals, which keeps out all microorganisms. (09 Oct 1997) |
| germ-free life | Animals not contaminated by or associated with any foreign organisms. (12 Dec 1998) |
| germ layer | <embryology> A layer of cells produced during the process of gastrulation during the early development of the animal embryo, which is distinct from other such layers of cells, as an early step of cell differentiation. The three types of germ layers are the endoderm, ectoderm, and mesoderm. Diploblastic organisms (e.g. Coelenterates) have two layers, ectoderm and endoderm, triploblastic organisms (all higher animal groups) have mesoderm between these two layers. Germ layers become distinguishable during late blastula/early gastrula stages of embryogenesis and each gives rise to a characteristic set of tissues, the ectoderm to external epithelia and to the nervous system for example: although some tissues contain elements derived from two layers. (18 Nov 1997) |
| germ layers | The three layers of cells comprising the early embryo. (12 Dec 1998) |
| germ layer theory | The developmental biology theory that during early development, the animal embryo divides itself into two or three germ layers, each of which then proceed to further differentiate into organs and tissues specific to that particular layer. (09 Oct 1997) |
| germ line | A group of cells in most multicellular animals which give rise to the reproductive cells. The genome of the animal as contained in these cells, along with any mutations which might arise in them (germinal mutations), can be passed on to offspring. Also can refer to the appearance and conditions of the genome in the germ cells which may be different from within the somatic cells. The development of a germ cell as originating from a cell in a zygote. (09 Oct 1997) |
| germ line gene therapy | The repair or replacement of a defective gene within the gamete-forming tissues, which produces an inheritable change in an organisms genetic constitution. (09 Oct 1997) |
| germ-line mutation | Any detectable and heritable alteration in the lineage of germ cells. Mutations in these cells (i.e., "generative" cells ancestral to the gametes) are transmitted to progeny while those in somatic cells are not. (12 Dec 1998) |