| 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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| immunologic and biological factors | A collective grouping for biologically active substances that play a role in the functioning of the immune system and those that show biological or physiological activity. (12 Dec 1998) |
| immunologic capping | The process by which lymphoid cell surface immunoglobulin receptors, when exposed to bivalent anti-ig antibodies, collect in patches and form a cap at one pole of the cell. The caps may then be endocytosed or shed into the environment in the form of antigen-antibody complexes. Capping has also been induced by lectins and antigens. (12 Dec 1998) |
| immunologic deficiency syndromes | Syndromes in which there is a deficiency or defect in the mechanisms of immunity, either cellular or humoral. (12 Dec 1998) |
| immunologic diseases | Disorders caused by abnormal or absent immunologic mechanisms, whether humoral, cell-mediated or both. (12 Dec 1998) |
| immunologic factors | Biologically active substances whose activities affect or play a role in the functioning of the immune system. (12 Dec 1998) |
| immunologic high dose tolerance | Induction of tolerance by exposure to large amounts of protein antigens. (05 Mar 2000) |
| immunologic memory | <immunology> The ability to rapidly produce large quantities of specific immune cells after subsequent exposure to a previously encountered antigen. (09 Oct 1997) |
| immunologic pregnancy test | A general term for test's for detection of increased human chorionic gonadotropin in plasma or urine by immunologic techniques including latex particle agglutination, haemagglutination inhibition, radioimmunoassay, and radioreceptor assays. (05 Mar 2000) |
| immunologic surveillance | The theory that T-cells monitor cell surfaces and detect structural changes in the plasma membrane and/or surface antigens of virally or neoplastically transformed cells. (12 Dec 1998) |
| immunologic tests | Diagnostic techniques involving the demonstration or measurement of an immune response, including antibody production or assay, antigen-antibody reactions, serologic cross-reactivity, delayed hypersensitivity reactions, or heterogenetic responses. (12 Dec 1998) |
| immunologic tolerance | Lack of immune response to antigen. Theories of tolerance induction include clonal deletion and clonal anergy. In clonal deletion, the actual clone of cells is eliminated whereas in clonal anergy the cells are present but nonfunctional. Synonym: immunological tolerance, immunotolerance, nonresponder tolerance. (05 Mar 2000) |
| ordered mechanism | A scheme for substrate binding and product release for multisubstrate enzymes; for a two-substrate two-product enzyme with an ordered mechanism, one particular substrate has to bind to the enzyme first followed by the other substrate; chemistry then occurs, products are formed and are released from the enzyme in a distinct order. More complex ordered schemes exist for enzymes having more than two substrates. Some of the dehydrogenases have such a mechanism. Synonym: ordered. (05 Mar 2000) |
| ordered on-random off mechanism | A scheme for substrate binding and product release for multisubstrate enzymes; for a two-substrate two-product enzyme with this mechanism, the individuals have to bind to the enzyme in a distinct order; however, once the products are formed they may dissociate from the enzyme in either order. It has been suggested that pyruvate kinase has such a mechanism. The random on-ordered off mechanism is simply the reverse of this mechanism. (05 Mar 2000) |