| maturation | 1. Achievement of full development or growth. 2. Developmental changes that lead to maturity. 3. Processing of a macromolecule; e.g., posttranscriptional modification of RNA or posttranslational modification of proteins. Origin: L. Maturatio, a ripening, fr. Maturus, ripe (05 Mar 2000) |
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| maturation arrest | Cessation of complete differentiation of cells at an immature stage; in spermatogenic maturation arrest, the seminiferous tubules contain spermatocytes, but no spermatozoa develop. (05 Mar 2000) |
| maturation factor | <biochemistry> Member of the water soluble B vitamin group, important in the proper function of the nervous system and important in proper carbohydrate, protein and fat metabolism. (27 Sep 1997) |
| maturation index | An index indicating the degree of maturation attained by the vaginal epithelium as adjudged by the cell types being exfoliated; serves as an objective means of evaluating hormonal secretion or response; represents the percentage of parabasal cells/intermediate cells/superficials, in that order; "shift to the left" indicates more immature cells on the surface (atrophy), while "shift to the right" indicates more mature epithelium. (05 Mar 2000) |
| maturation-promoting factor | <enzyme> A protein kinase that drives both the mitotic and meiotic cycles in all eukaryotic organisms. In meiosis it induces immature oocytes to undergo meiotic maturation. In mitosis it has a role in the G2/M phase transition. Once activated by cyclins, maturation-promoting factor directly phosphorylates some of the proteins involved in nuclear envelope breakdown, chromosome condensation, spindle assembly, and the degradation of cyclins. The catalytic subunit of maturation-promoting factor is protein p34cdc2. Acronym: MPF (12 Dec 1998) |
| maturation value | An indicator of the level of maturation attained by vaginal epithelium and used as a factor in cytohormonal evaluation from the maturation index by valuing the parabasal cells at 0.0, the intermediate cells at 0.5, and the superficial cells at 1.0; for special investigations, subtypes of a major cell can be given different values's. (05 Mar 2000) |
| sex maturation | Achievement of full sexual capacity. Applies to animals and humans. (12 Dec 1998) |
| sperm maturation | Posttesticular ripening of spermatozoa. (12 Dec 1998) |
| erythrocyte maturation factor | <biochemistry> Member of the water soluble B vitamin group, important in the proper function of the nervous system and important in proper carbohydrate, protein and fat metabolism. (27 Sep 1997) |
| acquired immunity | <immunology> A form of cellular defense which identifies certain foreign substances (antigens) as harmful to the body. For this reason, the body can acquire resistance to a particular foreign agent. These foreign agents are then attacked by sensitised T lymphocytes (cellular immunity). White blood cells, plasma cells, B lymphocytes and other specialised immune system cells act in concert with T lymphocytes to produce antibodies (humoral immunity) that attach to the antigen directing T-cells to attack. Antibodies also stimulate the release of special chemical mediators in the blood (for example complement, interferon) that further enhance antigen destruction. (13 Nov 1997) |
| active immunity | <immunology> An organisms resistance to disease or infection, developed because the organisms immune system has produced antibodies after an infection or innoculation. (06 May 1997) |
| adoptive immunity | <immunology> Immunity to disease or infection conferred on a previously non-immune individual by transferring lymphocytes from a previously immune individual to the non-immune individual. (15 Jan 1998) |
| allograft immunity | <immunology> The recipient's immune system rejects tissue grafted from a genetically dissimilar donor (of the same species) and stages an immune attack against it. (09 Oct 1997) |
| antiviral immunity | Immunity resulting from virus infection, either naturally acquired or produced by intentional vaccination; compared to some bacterial immunity's, it is of relatively long duration, but this may be the result of infection-immunity rather than being peculiar to virus infection per se, since it occurs also in bacterial immunity after infections such as typhoid fever. (05 Mar 2000) |
| artificial active immunity | See: acquired immunity. (05 Mar 2000) |