Search results for "platelet"

Staphylococcus aureus alpha-toxin attack on human platelets promotes assembly of the prothrombinase complex.

1990

alpha-Toxin, the major cytolysin of Staphylococcus aureus, promotes blood coagulation by its attack on human platelets (Bhakdi S., Muhly, M., Mannhardt, U., Hugo, F., Klapettek, K., Mueller-Eckhardt, C., and Roka, L. (1988) J. Exp. Med. 168, 527-542). In the present study we demonstrate that toxin attack on gel-filtered human platelets initiates the assembly of prothrombinase complexes at rates up to 10-fold of controls. Treatment of platelets with 0.1 microgram/ml alpha-toxin resulted in generation of 1.4 units of thrombin/10(8) platelets. A similar rate of thrombin generation was noted when platelets were subjected to three cycles of freezing and thawing. However, the alpha-toxin-induced …

Immune Thrombocytopenia: Recent Advances in Pathogenesis and Treatments

2021

Immune thrombocytopenia (ITP) is a rare autoimmune disease due to both a peripheral destruction of platelets and an inappropriate bone marrow production. Although the primary triggering factors of ITP remain unknown, a loss of immune tolerance—mostly represented by a regulatory T-cell defect—allows T follicular helper cells to stimulate autoreactive splenic B cells that differentiate into antiplatelet antibody-producing plasma cells. Glycoprotein IIb/IIIa is the main target of antiplatelet antibodies leading to platelet phagocytosis by splenic macrophages, through interactions with Fc gamma receptors (FcγRs) and complement receptors. This allows macrophages to activate autoreactive T cells …

Cellular effects of HMG-CoA reductase inhibitors on blood cells (monocytes, macrophages, platelets)

2002

Atherosclerosis is the primary cause of ischaemic heart disease (IHD) and stroke and the leading cause of death and long-term disabilities in westernized societies. Several important environmental and genetic risk factors are associated with atherosclerosis. Over the past decade, it has become evident that atherosclerosis is not simply an inevitable degenerative consequence of ageing, but rather a chronic inflammatory condition connecting altered cholesterol metabolism and other risk factors to the development and progression of the atherosclerotic lesion and its sequelae like plaque rupture, fibrosis, calcification and thrombosis [1].

Validation of the ISTH/SSC bleeding assessment tool for inherited platelet disorders: A communication from the Platelet Physiology SSC

2020

Background: Careful assessment of bleeding history is the first step in the evaluation of patients with mild/moderate bleeding disorders, and the use of a bleeding assessment tool (BAT) is strongly encouraged. Although a few studies have assessed the utility of the ISTH-BAT in patients with inherited platelet function disorders (IPFD) none of them was sufficiently large to draw conclusions and/or included appropriate control groups. Objectives: The aim of the present study was to test the utility of the ISTH-BAT in a large cohort of patients with a well-defined diagnosis of inherited platelets disorder in comparison with two parallel cohorts, one of patients with type-1 von Willebrand disea…

Endodontic management of single rooted immature mandibular second molar with single canal using MTA and platelet-rich fibrin membrane barrier: A case…

2011

An immature tooth with pulpal necrosis and periapical pathology imposes a great difficulty to the endodontists. Endodontic treatment options for such teeth consist of conventional apexification procedure with and without apical barriers. Various materials have been tried as apical matrix in the past. This article demonstrates the newer concept of using platelet rich fibrin membrane as an apical matrix barrier for stabilization of MTA in root end apexification procedure. Platelet Rich Fibrin is an autologous fibrin matrix containing a large quantity of platelet and leukocyte cytokines, which enhance healing by release of growth factors. This case report represents successful management of a …

Effects of Flurbiprofen on Platelet Function in Ihd Patients

1983

Lipid-Mediated Relation between Tissue Factor Pathway Inhibitor Activity and Cardiovascular Risk Factors and Diseases in a Large Population Sample

2018

Abstract Background: Tissue factor pathway inhibitor (TFPI), a Kunitz-type serine protease, is a potent anticoagulant protein in the extrinsic coagulation pathway and acts by inhibiting both the FXa and the Tissue Factor-FVIIa complex. In contrast to total and free TFPI antigen levels, the reference values and clinical determinants of total TFPI activity have not yet been studied in detail in the general population. In the present study, we aim to identify the cardiovascular determinants for total TFPI activity and investigate its association with cardiovascular disease (CVD) and total mortality, in a population at large. Methods: For this study, the first 4779 subjects of the population-ba…

TYPE II DIABETES MELLITUS HAS NO MAJOR INFLUENCE ON PLATELET MICRO–RNA EXPRESSION: RESULTS FROM MICRO–ARRAY PROFILING IN A COHORT OF 60 PATIENTS

2013

Blood platelets represent pro–inflammatory mediators in the development of atherosclerosis. Diabetes mellitus as a major contributor to cardiovascular disease burden induces dysfunctional platelets. Platelets contain abundant miRNAs, which recently have been linked tightly to inflammation. While

Generation of an Eosinophilotactic Factor from Human PMNs by Various Mechanisms of Cell Activation

1979

It is well established that an increase in the number of eosinophils both in tissue and in the circulation is a feature of many clinical conditions based on delayed (1,2) and immediate type hypersensitivity reactions (3,4). Since eosinophils have been recognised to exert specific killer function on parasites (5) and to be prominent participants at sites of inflammation, the mechanisms of their chemo-attraction are of major importance. In immediate type hypersensitivity reactions, eosinophils have been demonstrated to counteract the mediators of inflammation such as histamine (6), the SRS-A (7) and the platelet aggregating factor (8).

Bone Healing with or without Platelet-Rich Plasma around Four Different Dental Implant Surfaces in Beagle Dogs

2013

Purpose Surface development is one of the major aims in dental implant engineering. Additive application of substances could possibly improve the new bone formation around dental implants. The present study evaluated the bone reaction on four different implant surfaces with or without platelet-rich plasma (PRP). Materials and Methods Four self-tapping titanium screw implants (Branemark MK III [Nobel Biocare, Goteborg, Sweden], Osseotite [3i, Miami, FL, USA], Xive [Densply Friadent, Mannheim, Germany], and Compress [IGfZ eG, Diez, Germany]) with different surfaces were inserted in each hemimandible of 12 female beagle dogs; the implant positions and the application of PRP were randomized. Af…