OBJECTIVE To explore the effects of cytotoxin-associated gene A (CagA) positive Helicobacter pylori (H. pylori or HP) infection on circulating B cells producing specific platelet glycoprotein antibodies and the association between therapeutic outcomes in primary idiopathic thrombocytopenic purpura (ITP) patients. METHODS A total of 76 newly diagnosed primary ITP patients were included in the ...

We describe a new variant of Bernard-Soulier syndrome. The patient (W.K.) showed the classic bleeding symptoms together with absence of platelet agglutination to restocetin plus von Willebrand factor, whereas aggregation to ADP, collagen, and arachidonic acid was normal. Platelets were markedly larger than normal and the patient had life-long thrombocytopenia. Surface-labeling of the platelets ...

The human platelet-specific alloantigens HPA-2a and HPA-2b (= Kob and Koa) together constitute a biallelic antigen system. The HPA-2 antigens have not, to date, been located on a particular platelet membrane molecule. Here, we describe the localization of these antigens on platelet glycoprotein (GP) Ib alpha. Platelets from two patients with the Bernard-Soulier syndrome (BSS) were HPA-2(a-,b-) ...

in megakaryocyte development. There are several new clues: (1) A time course analysis indicates that expression of the von Wille-brand factor receptor and filamin A starts in immature megakaryocytes and increases just before proplatelet extension. (2) The association of GPIb to actin cytoskeleton occurs only in mature megakaryocytes and is filamin A– dependent, as in platelets. (3) GPIb␣ expres...

von Willebrand factor (vWF) is a large multimeric, multidomain glycoprotein found in platelets, endothelial cells and plasma. The A1, A2, and A3 domains in vWF mediate binding to glycoprotein Ib, ristocetin, botrocetin, collagen, sulphatides, and heparin and provide a protease cleavage site. Mutations causing types 2B, 2M, and 2A von Willebrand's disease (vWD) are located in the A1 and A2 domai...

The existing buffers algorithms cannot effectively to meet the demands of high accuracy buffer analysis in practice although many efforts have been made past 60 years. A generalized buffering algorithm (GBA) is presented, which considers geometric distance and attribute characteristics all instances within zone. proposed includes three major steps: (1) select initialize target instance; (2) det...

Redistribution of glycoproteins (GP) Ib, glycocalicin, IIb, and IIIa on the surface of human platelets in response to stimulation with corresponding monoclonal antibodies (MoAb) and a polyclonal antiglycocalicin antibody was studied by immunofluorescence, immunoelectron microscopy, and a quantitative radioimmune assay. Immobilization of the antigens by prefixation with formaldehyde showed a uni...

BACKGROUND The increased bleeding tendency of chronic renal failure (CRF) patients has been attributed to platelet dysfunction. However, reports on various platelet functions in uraemic patients have been conflicting. The present study sought to analyse platelet function by examining their surface glycoproteins in well-identified populations of CRF patients. METHODS Three groups were studied:...

Bernard-Soulier syndrome (BSS), also known as Hemorrhagiparous thrombocytic dystrophy, is a hereditary bleeding disorder affecting the megakaryocyte/platelet lineage and characterized by bleeding tendency, giant blood platelets and low platelet counts. This syndrome is extremely rare as only approximately 100 cases have been reported in the literature. Clinical manifestations usually include pu...

The present study has evaluated the hypothesis stating that glycoprotein (GP) Ib/IX, the receptor for von Willebrand factor (vWF), is downregulated and cleared from exposed surfaces to channels of the open canalicular system (OCS) on platelets activated by thrombin in suspension. Cryosections of resting and thrombin-activated platelets fixed at intervals of 1 to 30 minutes after stimulation by ...