P. N. Badenhorst

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A fully representative and viable platelet population was isolated from the blood of 15 baboons by a multiwash procedure, and labelled with In-111-oxine. The recovery of the total platelet population in the circulation was 85% +/- 9. Mean platelet life span was 146 hr +/- 13. Correcting for plasma radioactivity (always less than 3.5%) did not significantly(More)
BACKGROUND Systemic anticoagulation is required during cardiopulmonary bypass (CPB) to inhibit the activation of platelets, the coagulation system and ultimately thrombus formation. Unfractionated heparin is most commonly used, but it is neither entirely safe nor completely effective. The use of protamine sulphate to reverse the anticoagulant effect further(More)
Recombinant tick anticoagulant peptide (r-TAP) is a potent and specific inhibitor of activated coagulation factor X which effectively interrupts in vivo arterial thrombosis during treatment. It is, however, uncertain if it also affects thrombosis after treatment is stopped. This was tested in a baboon model of arterial thrombosis where platelet deposition(More)
Red cell volume (RCV) and plasma volume (PV) measurements are performed routinely in nuclear medicine departments to diagnose a number of haematological disorders. Currently, 125I-HSA is used as a plasma tracer and 99Tcm-labelled red cells to determine red cell volume. 125I-HSA is not always readily available, leading to inconvenience for patients and(More)
A new anticoagulant, recombinant hirudin, was given to healthy volunteers (5 per test dose) in single intravenous doses of 0.01, 0.02, 0.04, 0.07 and 0.1 mg/kg to study its anticoagulant effects, how it was tolerated and its pharmacokinetics. Hirudin proved to be a potent anticoagulant with important effects on thrombin (increase in thrombin time and(More)
Kinetics and quantification of the sites of destruction of 111-Indium-oxine-labeled autologous platelets were investigated in eight patients with idiopathic thrombocytopenic purpura. The mean platelet count was 17 +/- 9 X 10(9)/liter; platelets were separated by differential centrifugation and labeled with 5.6 +/- 2.5 MBq 111In. Whole body and organ(More)
Mean platelet survival and turnover were simultaneously determined with autologous 111In-labeled platelets (111In-AP) and homologous 51Cr-labeled platelets (51Cr-HP) in ten patients with chronic immune thrombocytopenic purpura (ITP). In vivo redistribution of the 111In-AP was quantitated with a scintillation camera and computer-assisted image analysis. The(More)
The pathogenesis of thrombocytopenia induced by intravenous protamine sulphate was studied in six patients who underwent cardiopulmonary bypass surgery, and in three normal volunteers. Autologous platelets were labelled with (111)Indium-oxine. Platelet lifespan was determined. In vivo (111)In-platelet localization, organ redistribution and sites of(More)
The survival, tissue distribution and fate of 111In-oxine labelled autologous platelets in six normal humans were studied with serial blood sampling, scintillation camera and computer-assisted imaging, whole body profile scanning, and rectilinear scanning. 111In-platelets recovery in the circulation was 72+/-16% and survival was 216+/-17 h. Platelet(More)
The effect of the chelates oxine and tropolone, used to label platelets, on the kinetics of indium-111-(111In) labeled platelets was studied in twelve normal human subjects. Autologous platelets were labeled either in saline with 111In-oxine or in plasma with 111In-tropolone. Mean platelet lifespan was estimated by fitting the disappearance curve of(More)