Counterflow centrifugal elutriation and Percoll density gradient centrifugation were employed to prepare cell populations from rat bone marrow that were selectively enriched in the cytoplasmically immature megakaryocytes and depleted of the most mature megakaryocytes. The incorporation of [14C]leucine into the platelet-specific alpha-granule protein, platelet factor 4, as well as the incorporat...

RA233, a new pyrimido-pyrimidine compound, is a powerful inhibitor of platelet function tested in vitro; it inhibits calcium and adenosine diphosphate (A.D.P.)-induced platelet aggregation, inhibits the retention of platelets by glass beads, decreases the release of platelet factor 3 by kaolin, and inhibits clot retraction. In some in-vitro systems RA233 is significantly more potent that its an...

OBJECTIVE Thrombosis occurs at sites of vascular injury when platelets adhere to subendothelial matrix proteins and to each other. Platelets express many surface receptor proteins, the function of several of these remains poorly characterized. Cadherin 6 is expressed on the platelet surface and contains an arginine-glycine-aspartic acid motif, suggesting that it might have a supportive role in ...

The phosphatidylinositol 3-kinase (PI 3-K) becomes activated when quiescent cells are stimulated with a variety of growth factors. We have microinjected antibodies specific for the p110 alpha subunit of the PI 3-K into quiescent fibroblasts and tested their effect on the ability of growth factors to stimulate exit from quiescence and entry into S phase. The antibodies inhibited platelet-derived...

By Gsaw n ALTSCHULER, AARON J. MARcus AND H uims L. Uu i N I HE HEMORRHAGIC tendency which develops in uremia is a well recognized clinical entity but the pathogenesis of this complication is not understood.’ In the past defective blood coagulation2 as well as increased vascular fragility3 have been suggested. The possibility of a functional blood platelet abnormality was first noted by Lewis, ...

Background: The present study evaluated treatment outcomes and the treatment indexes among Glanzmann’s patients in Mofid Children’s Hospital, Tehran, Iran. Patients and Methods: A retrospective cross-sectional study was performed to evaluate the treatment protocols on 15 Glanzmann’s patients with bleeding therapeutic records in Mofid Children’s Hospital, Tehran, Iran, from 2006 to 2011. Resu...

Because human platelets participate in the contact phase of intrinsic coagulation and contain a Factor XI-like coagulant activity, the nature of the Factor XI-like activity was examined and compared with purified plasma Factor XI. The platelet factor XI-like activity was sedimented with the particulate fraction of a platelet lysate, was inactivated by heat (t(1/2) 3.5 min, 56 degrees C), was no...