| immediate hypersensitivity reaction | An immune response mediated by antibody, usually IgE, which occurs within minutes after a second encounter with an antigen, resulting in the release of histamine and subsequent swelling and vasodilation. (05 Mar 2000) |
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| 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) |
| type III hypersensitivity reaction | An immunologic category of diseases evoked by the deposition of antigen-antibody or antigen-antibody-complement complexes on cell surfaces, with subsequent involvement of breakdown products of complement, platelets, and polymorphonuclear leukocytes, and development of vasculitis; nephritis is common. Arthus phenomenon and serum sickness are classic examples, but many other disorders, including most of the connective tissue disease's, may belong in this immunologic category; immune complex disease's can also occur during a variety of disease's of known aetiology, such as subacute bacterial endocarditis. See: autoimmune disease. Synonym: immune complex disorder, type III hypersensitivity reaction. (05 Mar 2000) |
| food hypersensitivity | Gastrointestinal disturbances, skin eruptions, or shock due to allergic reactions to allergens ingested in food. (12 Dec 1998) |
| acute bacterial endocarditis | A type of bacterial endocarditis caused by pyogenic organisms such as haemolytic streptococci or staphylococci. (05 Mar 2000) |
| adhesins, bacterial | Cell-surface components or appendages of bacteria that facilitate adhesion (bacterial adhesion) to other cells or to inanimate surfaces. most fimbriae (fimbriae, bacterial) of gram-negative bacteria function as adhesins, but in many cases it is a minor subunit protein at the tip of the fimbriae that is the actual adhesin. In gram-positive bacteria, a protein or polysaccharide surface layer serves as the specific adhesin. (12 Dec 1998) |
| antibodies, bacterial | Immunoglobulins induced by substances elaborated by bacteria that have an antigenic activity. (12 Dec 1998) |
| antigens, bacterial | Substances elaborated by bacteria that have antigenic activity. (12 Dec 1998) |
| atypical bacterial forms | Microorganisms that have undergone greater changes than normal in morphology, physiology, or cultural characteristics. (12 Dec 1998) |
| bacteria-free stage of bacterial endocarditis | Endocarditis described prior to the antibiotic era and presumably due to spontaneous healing of the bacterial vegetations. (05 Mar 2000) |
| bacterial | <microbiology> Bacteria are group of micro-organisms that are a single cell approximately 1 micron in transverse diameter. Some bacteria cause disease in man, requiring treatment with an antibiotic. (27 Sep 1997) |
| bacterial adhesion | Physicochemical property of fimbriated (fimbriae, bacterial) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity. (12 Dec 1998) |
| bacterial allergy | The concept that the atopic kind of type I allergic reactions may be caused by bacterial allergens, the delayed type of skin test, so-called because of its early association with bacterial antigens (e.g., the tuberculin test). (05 Mar 2000) |
| bacterial antagonism | The inhibition of one bacterium by products of another. (05 Mar 2000) |
| bacterial capsule | A layer of slime of variable composition which covers the surface of some bacteria; capsulated cells of pathogenic bacteria are usually more virulent than cells without capsules because the former are more resistant to phagocytic action. (05 Mar 2000) |