| LACN | local area communications network |
|---|---|
| LAN | local area network; long-acting neuroleptic [agent] |
| LAS | laboratory automation system; lateral amyotrophic sclerosis; laxative abuse syndrome; left anterior-... |
| LCBF | local cerebral blood flow |
| LCGU | local cerebral glucose utilization |
| local treatment | Treatment that affects the tumour and the area close to it. (12 Dec 1998) |
|---|---|
| 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) |
| artificial passive immunity | See: acquired immunity. (05 Mar 2000) |
| bacteriophage immunity | The state induced in a bacterium by lysogenization, the lysogenic bacterium being insusceptible to further lysogenization or to a lytic cycle by a superinfecting bacteriophage, in contradistinction to bacteriophage resistance. (05 Mar 2000) |
| general immunity | Immunity associated with widely diffused mechanisms that tend to protect the body as a whole, as compared with local immunity. (05 Mar 2000) |
| maternal immunity | <epidemiology> Immunity for a neonate provided by IgG antibody generated by a mother and passed across the placenta to the unborn offspring. This provides short lived protection (with a typical half life of 3-6 months) to the neonate. Also known as immunity. (05 Dec 1998) |
| passive immunity | <immunology> Immunity acquired by the transfer from another animal of antibody or sensitised lymphocytes. Passive transfer of antibody from mother to offspring is important for immune defense during the perinatal period. (18 Nov 1997) |
| relative immunity | A modified, not completely effective resistance that results when there is a sort of "fluctuating equilibrium" between the defense mechanisms of the host and the infective agent. (05 Mar 2000) |
| cell-mediated immunity | <immunology> Immune response that involves effector T lymphocytes and not the production of humoral antibody. Responsible for allograft rejection, delayed hypersensitivity and in defence against viral infection and intracellular protozoan parasites. (26 Mar 1998) |
| cellular immunity | <cell biology, immunology> Immune response that involves enhanced activity by phagocytic cells and does not imply lymphocyte involvement. Since the term is easily confused with cell-mediated immunity its use in this sense should be avoided. (26 Mar 1998) |