Biomedical subjects
Publications and source records attributed to J L Hahn.
Nurses should assume a more active role in developing effective preventative health care programs. A successful, cost-effective collaborative approach to heart and stroke education has been developed that all nurses can use in a variety of settings.
Collagenase produced by monolayer cultures of rabbit synovial fibroblasts was purified from serum-free culture medium. Antiserum to the pure preparation was raised in sheep. The IgG fraction has been isolated and characterized and shown to be specific for collagenase. The antibody is capable of precipitating and inhibiting the activity of both latent and activated rabbit synovial fibroblast collagenase. Cross-reactivity with human antigen from rheumatoid synovial cell culture medium is described.
Microcrystalline cholesterol in either the anhydrous or monohydrate form was a potent activator of the alternative pathway of complement as measured by the electrophoretic conversion (crossed immunoelectrophoresis) of C3 and properdin factor B. Chelation with 0.01 M ethylene-diaminetetraacetate (EDTA) completely eliminated conversion, but 0.01 M ethyleneglycol tetraacetate (EGTA) had little or no effect. The magnitude of activation by cholesterol crystals was similar to that by zymosan, heat-aggregated IgG, or crystals of monosodium urate monohydrate. The microcrystalline forms of the acetate, linoleate, or oleate esters of cholesterol did not activate more complement than did saline controls. Cholestanol retained full C3 activating potency, but cholestane had none. Binding of IgG by cholesterol monohydrate is very small compared to that by sodium urate.
Exposure of murine peritoneal macrophages to crystals of monosodium urate monohydrate (MSUM) stimulated release of inflammatory mediators from the cells. There was an early, rapid burst of prostaglandin E2 (PGE2) synthesis which was complete by 2 h. Release of N-acetyl glucosaminidase (NAG), a lysosomal enzyme, was evident within 1 h and was maximal by 8 h. Early release of lysosomal enzymes (1-2 h) was not accompanied by leakage of cytoplasmic enzymes; however, treatment with high concentrations of MSUM, or prolonged exposure to crystals, provoked release of the cytoplasmic enzyme lactate dehydrogenase, presumably as a result os cell lysis. Responses of macrophages to MSUM occurred in the absence of serum but were modified by serum proteins. Prior exposure of crystals to IgG potentiated release of NAG and PGE2. Exposure to albumin slightly enhanced release of PGE2 induced by MSUM but did not affect NAG release. However, albumin prevented enhancement of NAG release by IgG. The interaction of MSUM with macrophages, and subsequent release of inflammatory mediators, may contribute to the inflammation association with both acute and chronic gouty arthritis.