| minimal reacting dose | The minimal dose of a toxic substance causing a reaction, as manifested in the skin of a series of susceptible test animals; the assay is based on the development of a characteristic, minimal but definite, "standard," focal inflammation (congestion and oedema, induration, degenerative changes, and desquamation of epidermal cells). (05 Mar 2000) |
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| cross-reacting agglutinin | An immune agglutinin specific for a group antigen. Synonym: cross-reacting agglutinin. (05 Mar 2000) |
| cross-reacting antibody | <immunology> Antibody specific for group antigens, i.e., those with identical functional groups, antibody for antigens that have functional groups of closely similar, but not identical, chemical structure. (05 Mar 2000) |
| cross-reacting material | <haematology> A substance sufficiently different from a reference substance (R) to have a perceptibly different function from R but sufficiently similar to R that it reacts with anti-R antibodies; e.g., mutant factor VIII may be defective or even inert in coagulation and yet be immunologically identified as factor VIII. (05 Mar 2000) |
| slow-reacting factor of anaphylaxis | Slow-reacting substance of anaphylaxis (SRS-A), a leukotriene of low molecular weight which is released in anaphylactic shock and produces slower and more prolonged contraction of muscle than does histamine; it is active in the presence of antihistamines (but not epinephrine) and seems not to occur preformed in mast cells, but as a result of an antigen-antibody reaction on the granules. Compare: peptidyl leukotrienes. Synonym: slow-reacting factor of anaphylaxis. (05 Mar 2000) |
| slow-reacting substance | Slow-reacting substance of anaphylaxis (SRS-A), a leukotriene of low molecular weight which is released in anaphylactic shock and produces slower and more prolonged contraction of muscle than does histamine; it is active in the presence of antihistamines (but not epinephrine) and seems not to occur preformed in mast cells, but as a result of an antigen-antibody reaction on the granules. Compare: peptidyl leukotrienes. Synonym: slow-reacting factor of anaphylaxis. (05 Mar 2000) |
| slow reacting substance of anaphylaxis | <immunology> Potent bronchoconstrictor and inflammatory agent released by mast cells, an important mediator of allergic bronchial asthma. A mixture of three leukotrienes (LTC4 mainly, LTD4 and LTE4) (18 Nov 1997) |
| direct reacting bilirubin | The fraction of serum bilirubin which has been conjugated with glucuronic acid in the liver cell to form bilirubin diglucuronide; so called because it reacts directly with the Ehrlich diazo reagent; increased levels are found in hepatobiliary diseases, especially of the obstructive variety. Synonym: conjugated bilirubin. (05 Mar 2000) |
| indirect reacting bilirubin | The fraction of serum bilirubin which has not been conjugated with glucuronic acid in the liver cell; so called because it reacts with the Ehrlich diazo reagent only when alcohol is added; increased levels are found in hepatic disease and haemolytic conditions. Synonym: unconjugated bilirubin. (05 Mar 2000) |
| absorbed dose | The amount of energy absorbed per unit mass of irradiated material at the target site; in radiation therapy, the former unit for absorbed dose is the rad; the current (S.I.) unit is the gray. (05 Mar 2000) |
| air dose | The radiation dose, expressed in roentgens, delivered at a point in free air. Synonym: air dose. (05 Mar 2000) |
| bone marrow dose | The cumulative dose to the blood-forming organ from therapeutic or nuclear fallout irradiation; the presumed leukemogenic dose. (05 Mar 2000) |
| booster dose | A dose given at some time after an initial dose to enhance the effect, said usually of antigens for the production of antibodies. (05 Mar 2000) |
| breast dose in mammography | <radiology> 180 mrad / view -- mid-breast dose, guideline: less than 1 rad for 2-view exam (12 Dec 1998) |
| maintenance dose | In chemotherapy, systematic dosage at a level that maintains protection against exacerbation. (05 Mar 2000) |