Electron microscopic studies of quinine induced ultrastructural changes to platelets.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to S Deacon.
Explore the source record for details and available documents.
Quinine, a drug known to induce immune mediated thrombocytopenia, has been postulated to mediate binding of drug dependent antibodies to a range of platelet membrane glycoproteins. Quinine may not act solely as a hapten however, as we have shown that it inhibits platelet aggregation (ex vivo and in vitro) and release and modifies the ability of activated platelets to bind the adhesive proteins fibrinogen and fibronectin in a dose dependent fashion. Studies on the effect of quinine on the binding of monoclonal antibodies HuPlml (GpIIIa) FMC25 (GpIX) and AN51 (GpIb) to platelets shows a selective reduction in AN51 binding. In addition quinine induced platelet antibodies from thrombocytopenic patients, in the presence of quinine, have been shown to inhibit binding of these monoclonal antibodies to platelets to varying degrees. These observations suggest that quinine causes widespread but specific conformational changes in platelet membrane antigens which may expose neoantigens resulting in the production of quinine induced antibodies.
Explore the source record for details and available documents.
Standard curves were prepared by plotting log gentamicin concentration against zone diameter using a conventional plate diffusion method. Results were obtained at varying concentrations of sodium chloride and at different pHs. Under optimum conditions the range in zone diameters was markedly increased, thus considerably improving the potential accuracy of the plate assay method.
A comparison of standard curves obtained from a conventional plate diffusion assay method revealed significant differences when gentamicin standards were made up in different media. Standards made up in distilled water resulted in a curve which differed from that of standards made up in pooled human cerebrospinal fluid by a factor of up to 4. When the assay medium was supplemented with 0-5% sodium chloride, the difference between the two standard curves was reduced to a factor of about 1-5. The curve obtained from standards made up in 150 mM sodium chloride/4-5 mM calcium chloride correlated well with that from standards made up in cerebrospinal fluid. There was no evidence of gentamicin being bound to protein in the cerebrospinal fluid.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.