| TSD | target-skin distance; Tay-Sachs disease; theory of signal detectability |
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| BCDSP | Boston Collaborative Drug Surveillance Program |
| CDSC | Communicable Diseases Surveillance Centre [London] |
| COMPASS | Computerized Online Medicaid Pharmaceutical Analysis and Surveillance System |
| CSS | Cancer Surveillance System; carotid sinus stimulation; carotid sinus syndrome; cavernous sinus syndr... |
| immunological mechanism | The groups of cells (chiefly lymphocytes and cells of the reticuloendothelial system) that function in establishing active acquired immunity (induced sensitivity, allergy). (05 Mar 2000) |
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| immunological memory | <immunology> The systems responsible for the situation where reactions to a second or subsequent exposure to an antigen are more extensive than those seen on first exposure (but See immunological tolerance. The memory is best explained by clonal expansion and persistence of such clones following the first exposure to antigen. (18 Nov 1997) |
| immunological network | <immunology> The concept due to Jerne that the entire specific immune system within an animal is made up of a series of interacting molecules and cell surface receptors, based on the idea that every antibody combining site carries its own marker antigens or idiotypes and that these in turn may be recognised by another set of antibody combining sites and so on. (18 Nov 1997) |
| immunological paralysis | Lack of specific antibody production after exposure to large doses of the antigen; immunological paralysis disappears when the antigen is eliminated. See: immunologic tolerance. (05 Mar 2000) |
| immunological tolerance | <immunology> Specific unresponsiveness to antigen. Self tolerance is a process occurring normally early in life due to suppression of self reactive lymphocyte clones. Tolerance to foreign antigens can be induced in adult life by exposure to antigens under conditions in which specific clones are suppressed. Note that tolerance is not the same as immunological unresponsiveness, since the latter may be very non-specific as in immunodeficiency states. (18 Nov 1997) |
| Abbe theory of image formation | <optics, physics> Abbe's theory is based on the fact that a non-self-luminous particle, which is illuminated by an extraneous source, gives rise to diffracted light rays, in addition to the dioptric pencil. He stated that to form a good microscopical image as many of the diffracted rays as possible should be intercepted by the objective. With closely ruled lines, his theory is easily demonstrated by observing the back lens of the objective, for here the diffracted rays can be observed directly if the aperture diaphragm is closed. It can be shown that, when the illumination is arranged to exclude the diffracted images, resolution is lost. (11 Mar 1998) |
| adsorption theory of narcosis | That a drug becomes concentrated at the surface of the cell as a result of adsorption, and thus alters permeability and metabolism. (05 Mar 2000) |
| Altmann's theory | A theory that protoplasm consists of granular particles (called bioblasts) that are clustered and enclosed in indifferent matter. (05 Mar 2000) |
| Arrhenius-Madsen theory | That the reaction of an antigen with its antibody is a reversible reaction, the equilibrium being determined according to the law of mass action by the concentrations of the reacting substances. (05 Mar 2000) |
| atomic theory | That chemical compounds are formed by the union of atoms in certain definite proportions; in its modern form, first advanced in 1803 by John Dalton. (05 Mar 2000) |
| Baeyer's theory | That carbon bonds are set at fixed angles (109 |
| balance theory | In social psychology, a theory which assumes that steady and unsteady states can be specified for cognitive units, such as an individual and his or her attitudes or acts, and that such units tend to seek steady states (balance); e.g., balance exists when both parts of a unit are evaluated the same, but disequilibrium arises when both parts are not evaluated the same, which causes either cognitive reevaluation of the parts or their segregation. See: cognitive dissonance theory, consistency principle. (05 Mar 2000) |
| beta-oxidation-condensation theory | <biochemistry> That the two carbon fragments split from the fatty acid molecule by beta-oxidation are converted to acetic acid and then condensed to acetoacetic acid. (05 Mar 2000) |
| Bohr's theory | That spectrum lines are produced 1) by the quantised emission of radiant energy when electrons drop from an orbit of a higher to one of a lower energy level, or 2) by absorption of radiation when an electron rises from a lower to a higher energy level. (05 Mar 2000) |
| Bordeau theory | That each organ of the body manufactured a specific humor which it secreted into the bloodstream. (05 Mar 2000) |