Factor Activation Of Platelets
Mostrando 13-24 de 85 artigos, teses e dissertações.
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13. Protease-activated receptor 1 is the primary mediator of thrombin-stimulated platelet procoagulant activity
The activation of human platelets by thrombin is mediated primarily by protease-activated receptors (PARs). PAR1 and PAR4 are present on human platelets and are activated by the hexapeptides SFLLRN and GYPGQV, respectively. To further characterize the involvement of PAR1 and PAR4 in platelet activation, the ability of SFLLRN or GYPGQV to generate annexin V b
The National Academy of Sciences.
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14. Activation of Rabbit Platelets by Platelet-Activating Factor Derived from IgE-Sensitized Basophils: CHARACTERISTICS OF THE AGGREGATION AND ITS DISSOCIATION FROM SECRETION
Platelet-activating factor (PAF) is liberated from antigen-stimulated, IgE-sensitized rabbit basophils and induces aggregation of platelets and secretion of their content of vasoactive amines. Experiments were performed to determine the relationship between these two platelet responses to this stimulus.
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15. von Willebrand factor binding to platelet GpIb initiates signals for platelet activation.
The hypothesis that von Willebrand factor (vWF) binding to platelet membrane glycoprotein Ib (GpIb) initiates intracellular pathways of platelet activation was studied. We measured the biochemical responses of intact human platelets treated with ristocetin plus vWF multimers purified from human cryoprecipitate. vWF plus ristocetin causes the breakdown of pho
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16. Regulation of platelet granule exocytosis by S-nitrosylation
Nitric oxide (NO) regulates platelet activation by cGMP-dependent mechanisms and by mechanisms that are not completely defined. Platelet activation includes exocytosis of platelet granules, releasing mediators that regulate interactions between platelets, leukocytes, and endothelial cells. Exocytosis is mediated in part by N-ethylmaleimide-sensitive factor (
National Academy of Sciences.
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17. High molecular weight kininogen binds to unstimulated platelets.
Studies were performed to determine if the unstimulated platelet membrane has a site for high molecular weight kininogen (HMWK) binding. 125I-HMWK bound to unstimulated platelets. Zn++ was required for 125I-HMWK binding to unstimulated platelets and binding was maximal at 50 microM Zn++. Neither Mg++ nor Ca++ substituted for Zn++ in supporting 125I-HMWK bind
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18. Neutrophil accumulation on activated, surface-adherent platelets in flow is mediated by interaction of Mac-1 with fibrinogen bound to alphaIIbbeta3 and stimulated by platelet-activating factor.
We have studied the pathways that lead to arrest and firm adhesion of rolling PMN on activated, surface-adherent platelets. Stable arrest and adhesion strengthening of PMN on thrombin-stimulated, surface-adherent platelets in flow required distinct Ca2+- and Mg2+-dependent regions of Mac-1 (alphaMbeta2), and involved interactions of Mac-1 with fibrinogen, wh
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19. Platelet-derived collagenase inhibitor: characterization and subcellular localization.
Purified human platelets were found to contain a collagenase inhibitor that is immunologically, functionally, and chromatographically identical to that produced by human skin fibroblasts. None of the other formed elements of the blood (erythrocytes, granulocytes, mononuclear cells) possessed detectable quantities of this protein. Virtually all the collagenas
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20. Monoclonal immunoglobulin M lambda coagulation inhibitor with phospholipid specificity. Mechanism of a lupus anticoagulant.
Prolongation of all phospholipid-dependent coagulation tests was found in a patient with macroglobulinemia, despite absence of bleeding manifestations. The purified monoclonal IgM lambda protein and its Fabmu tryptic fragment induced similar changes in normal plasma. Patient IgM and Fabmu completely inhibited Ca++-dependent binding of radiolabeled prothrombi
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21. Human Platelets Damage Aspergillus fumigatus Hyphae and May Supplement Killing by Neutrophils
Neutropenia is considered a significant risk factor for invasive aspergillosis but is almost always associated with concurrent thrombocytopenia. Studies determined that platelets, like neutrophils, attached to cell walls of the invasive hyphal form of Aspergillus fumigatus. Organisms were damaged as shown by loss of cell wall integrity in scanning laser conf
American Society for Microbiology.
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22. Gray platelet syndrome. Demonstration of alpha granule membranes that can fuse with the cell surface.
Platelets from patients with the gray platelet syndrome have decreased recognizable alpha granules and are markedly deficient in some alpha-granule secretory proteins. Using immunocytochemical techniques with antibodies to an alpha-granule membrane protein, GMP-140, we identified the membranes of intracellular vesicles in gray platelets as alpha-granule memb
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23. A new murine monoclonal antibody reports an activation-dependent change in the conformation and/or microenvironment of the platelet glycoprotein IIb/IIIa complex.
Considerable evidence indicates that the glycoprotein (GP) IIb/IIIa complex on human platelets functions as a receptor for fibrinogen, but little is known about the mechanism of receptor "exposure." To investigate this mechanism, our previously described murine monoclonal antibody (10E5) and a new monoclonal antibody (7E3), both of which block the binding of
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24. Human Platelets and Factor XI: LOCALIZATION IN PLATELET MEMBRANES OF FACTOR XI-LIKE ACTIVITY AND ITS FUNCTIONAL DISTINCTION FROM PLASMA FACTOR XI
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 (