| hypersensitivity vasculitis | An acute form of vasculitis which may affect the skin only, but also may involve other organs, with a polymorphonuclear infiltrate in the walls of and surrounding small (dermal) vessels. Nuclear fragments are formed by karyorrhexis of the neutrophils. See: leukocytoclastic vasculitis. Synonym: allergic angiitis, hypersensitivity vasculitis. (05 Mar 2000) |
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| DNAse i hypersensitivity site | <molecular biology> A site on a DNA molecule that is especially prone to being cut apart by the endonuclease enzyme DNase I, which breaks down DNA into smaller fragments by cleaving phosphodiester bonds. These sites tend to be near active genes, which are regularly transcribed. (09 Oct 1997) |
| drug hypersensitivity | Immunologically mediated adverse reactions to medicinal substances used legally or illegally. (12 Dec 1998) |
| immediate hypersensitivity | An exaggerated immune response mediated by antibodies, in particular IgE. See: allergy. (05 Mar 2000) |
| tuberculin-type hypersensitivity | A local or generalised response that begins 24 to 48 hours after exposure to an antigen. See: cell-mediated reaction. Synonym: contact hypersensitivity, delayed hypersensitivity, late reaction, tuberculin-type hypersensitivity. (05 Mar 2000) |
| food hypersensitivity | Gastrointestinal disturbances, skin eruptions, or shock due to allergic reactions to allergens ingested in food. (12 Dec 1998) |
| prenatal exposure delayed effects | Delayed effects on offspring of maternal or foetal prenatal exposure to drugs, radiation and other physical agents, manipulation, nutrition, stress, etc. (12 Dec 1998) |
| puberty, delayed | Unusually late sexual maturity. (12 Dec 1998) |
| delayed-action preparations | Dosage forms of a drug that act over a period of time. (12 Dec 1998) |
| delayed allergy | A type IV allergic reaction; so called because in a sensitised subject the reaction becomes evident hours after contact with the allergen (antigen), reaches its peak after 36 to 48 hours, then recedes slowly. Associated with cell-mediated responses. See: delayed reaction. Compare: immediate allergy. (05 Mar 2000) |
| delayed coma after hypoxia | Coma that develops a few days to 3 weeks after an acute hypoxic insult; the latter was usually severe enough to cause an initial bout of coma, which cleared, and was followed by a transient interval of apparent normality. Synonym: severe postanoxic encephalopathy. (05 Mar 2000) |
| delayed conduction | First-degree A-V block. See: atrioventricular block, intraventricular block, bundle-branch block. (05 Mar 2000) |
| delayed dentition | Delayed eruption of the teeth. (05 Mar 2000) |
| delayed eruption | A dental eruption pattern which is chronologically late in comparison with the average pattern of dental eruption; eruption of the first tooth occurs at a later age than the average, and the intervals of time between subsequent dental eruption's are longer than the average. Drug eruption, any eruption caused by the ingestion, injection, or inhalation of a drug, most often the result of allergic sensitization; reactions to drugs applied to the cutaneous surface are not generally designated as drug eruption, but as contact-type dermatitis. Synonym: dermatitis medicamentosa, dermatosis medicamentosa, drug rash, medicinal eruption. (05 Mar 2000) |
| delayed flap | A flap raised in its donor area in two or more stages to increase its chances of survival after transfer. (05 Mar 2000) |