AIDS - 3. Type I IgE Mediated a. IgE attaches to membrane...

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AIDS A. HIV - Retrovirus B. Destroys T-helper lymphocytes Hypersensitivities (Allergies) A. Two types hypersensitive reactions: 1. Immediate type hypersensitivities a. Reactions usually occur within short period of time b. Antibody mediated 2. Delayed type hypersensitivities a. Reactions usually occur after longer period of time b. Cell mediated (T DH lymph) 3. Allergen - antigens which tend to induce hypersensitive reaction rather than protective immunity B. Immediate Hypersensitivities 1. General characteristics: a. Humoral Ab. occur in plasma “sensitized” individual b. Must be acquired due to previous exposure “sensitized” c. Reactions occur within average 20-30 min. following exposure allergen d. Manifestations usually acute (severe) but subside quickly when allergen no longer present 2. Three types immediate hypersensitivities a. Type I - IgE mediated - most common b. Type II – Cytotoxic reactions c. Type III – Immune complex reactions
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Unformatted text preview: 3. Type I IgE Mediated a. IgE attaches to membrane of mast cells b. Location mast cells skin, m.m. of R.T. and G.I. tract, endothelium, smooth muscles (internal organs) c. Development 1). Primary exposure: a). Exposed to allergen first time b). Production IgE antibodies c). IgE attaches to membrane mast cells sensitized 2). Subsequent exposure: a). Allergen comes in contact with sensitized tissues b). Allergen reacts with IgE on mast cells c). Ag-Ab reaction causes lysis cell membrane d). Mast cells release granules degranulation e). Granules broken down in tissues f). Release histamine, heparin, and other chemicals g). Physiological effects: [ 1 ] . Vasodilation [ 2 ] . Vascular permeability [ 3 ] . Mucus secretions [ 4 ] . Smooth muscle contraction [ 5 ] . Anticoagulation (heparin)...
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This note was uploaded on 01/23/2012 for the course MCB MCB2010 taught by Professor Smith during the Fall '09 term at Broward College.

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AIDS - 3. Type I IgE Mediated a. IgE attaches to membrane...

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