The topographic relationships of platelet membrane glycoprotein IIb and glycoprotein IIIa have been studied in stimulated and unstimulated human platelets using immunoelectron microscopy. An indirect approach with ferritin-conjugated goat anti-rabbit gamma-globulin was used to localize the rabbit antibody to glycoprotein IIIa. The second ultrastructural label was keyhole limpet hemocyanin conju...

Interaction between human platelets and platelet plasma membrane with apparent bacterial endotoxin was studied in vitro attempts at repair, pseudopod formation, with transmission and scanning electron and centralization of platelet organdIes. microscopy. Washed human platelets, Copper appeared to potentiate these phewhose aggregation was blocked with nomena, since neither Cu2+ at low concenapyr...

background: platelets rapidly lose their qualities usually after 5 day of storage. different standard methods have been recommended to check the quality of platelets during storage which some of them show better correlation with other quality markers during storage. the purpose of this study was to demonstrate if platelet factor 3 (pf3) assay could be an indicator of storage lesion and provide ...

Bernard-Soulier syndrome (BSS) is a rare autosomal bleeding disorder characterized clinically by prolonged skin bleeding time, normal clot retraction and thrombocytopenia with large and morphologically abnormal platelets, and biochemically by the absence of platelet membrane glycoproteins (GP) Ib, V and IX. GP Ib and GP IX exist in the platelet membrane as a heterodimer complex which acts as th...

We recently showed that platelets contain submembranous actin filaments that are linked to glycoprotein (GP) Ib on the plasma membrane. In the present study, experiments were performed to determine whether spectrin was associated with these filaments. The membrane-bound filaments were isolated from Triton X-100 (Sigma, St Louis) lysates of unstimulated platelets by differential centrifugation. ...

Two hereditary platelet disorders, Bernard-Soulier syndrome and Glanzmann's thrombasthenia, are characterized by selective deficiencies of platelet membrane glycoproteins. Murine monoclonal antibodies were developed against platelet membrane glycoprotein Ib and against the glycoprotein IIb/IIIa complex. A rapid whole blood assay for the deficiency of these glycoproteins was developed and used t...

Subcellular membrane and granule fractions derived from human platelets contain factor VIIII antigen and von Willebrand factor activity but not factor VII procoagulant activity. Circulating platelets constitute a significant reservoir of plasma factor VIII antigen, containing approximately 15% of the amount of factor VIII antigen present in platelet-poor plasma. The antibiotic ristocetin, which...

background: immune thrombocytopenia is a hematologic disorder characterized by low platelet count and variable bleeding manifestations due to immune-mediated platelet destruction and/or suppression of platelet production. this study was performed to evaluate characteristics and clinical presentations of adult patients with immune thrombocytopenia and to explore the clinical value of platelet an...

The cellular phospholipid membrane plays an important role in cell function and cell-cell communication, but its biocomplexity and dynamic nature presents a challenge for examining cellular uptake of phospholipids and the resultant effects on cell function. Platelets, small anuclear circulating cell bodies that influence a wide variety of physiological functions through their dynamic secretory ...

Platelet membrane glycoprotein Ib (GPIb) and the GPIIb-IIIa complex have central roles in the interaction of platelets with the plasma coagulation system, damaged vessel walls, and other platelets. We investigated the effects of thrombin on these glycoproteins. Monoclonal antibodies were used to assess platelet surface glycoproteins by flow cytometry, total platelet glycoprotein content by immu...