Todd McDonald

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Previously, recombinant erythropoietin (rEpo) was shown to increase the number and size of megakaryocytic colonies in vitro, and in vivo it elevates the number of megakaryocytes in mouse spleens. To test the hypothesis that rEpo would stimulate platelet production in mice, both normal mice and mice in rebound-thrombocytosis were injected with rEpo and the(More)
Primary or essential thrombocythemia is rarely observed in childhood, and familial occurrence has been reported only once. In this study, essential thrombocythemia is documented in five members of both sexes from two to 62 years of age in three successive generations. The propositus had a persistent elevation of the platelet count, splenomegaly, a normal(More)
Thyroxine has been shown in vitro to stimulate erythropoiesis by two mechanisms: a direct, beta 2-adrenergic receptor-mediated stimulation of red cell precursors, and an indirect, erythropoietin-mediated mechanism. Clinical reports have suggested that excess thyroxine also exerts depressive effects on thrombocytopoiesis, but the most sensitive methods of(More)
Human embryonic kidney cells were maintained in culture in a medium containing lactalbumin hydrolysate for 5 to 6 weeks and the supernatant fluid tested for thrombopoietin content. Thrombopoietin was determined by a bioassay procedure which utilized mice that were in rebound thrombocytosis. The results indicate that the medium from kidney cells in culture(More)