Thrombosis research
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This is the first paper reporting a performance verification study of a point-of-care (POC) monitor for prothrombin time (PT) testing according to the requirements given in chapter 8 of the International Organization for Standardization (ISO) 17593:2007 standard "Clinical laboratory testing and in vitro medical devices - Requirements for in vitro monitoring systems for self-testing of oral anticoagulant therapy". The monitor under investigation was the new CoaguChek XS system which is designed for use in patient self testing. Its detection principle is based on the amperometric measurement of the thrombin activity generated by starting the coagulation cascade using a recombinant human thromboplastin. ⋯ The new system demonstrated a high level of trueness and accuracy, and low imprecision in INR testing. It can be concluded that the CoaguChek XS system complies with the requirements in chapter 8 of the ISO standard 17593:2007.
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Thrombosis research · Jan 2008
Venous thromboembolism in patients with pancreatic adenocarcinoma: lower incidence in Asian ethnicity.
Pancreatic adenocarcinoma is one of the cancers most frequently associated with venous thromboembolism (VTE), with the varying incidences of 10%-20% reported in Western countries. Asians are known to have a lower risk for VTE than Caucasians, but few studies have been conducted regarding the incidence of VTE in Asian cancer patients. ⋯ The incidence of VTE complications in Korean patients with advanced pancreatic cancer was 5.3%, which is lower than that observed in other ethnic groups. Our study warrants further prospective investigations on the incidence and mechanism of VTE and cerebral infarctions in cancer patients of different ethnic groups.
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Thrombosis research · Jan 2008
Are patients with thrombophilia and previous venous thromboembolism at higher risk to arterial thrombosis?
Whether thrombophilic disorders, which are established risk factors for venous thromboembolism (VTE), also increase the risk of arterial thrombosis is still unknown. ⋯ The cumulative incidence of arterial thrombotic events in VTE patients is low, and the inherited thrombophilias do not seem to substantially increase the risk of arterial thrombosis.
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Thrombosis research · Jan 2008
Visual evaluation of blood coagulation during mural thrombogenesis under high shear blood flow.
Mural thrombus generation at sites of damaged vessel walls is essential for both physiological haemostasis and pathological intravascular thrombosis. While thrombi are established by the concerted action of platelet aggregation and blood coagulation, most previous in vitro coagulation assays have evaluated fibrin clot formation in a closed stirring situation that lacks blood cells including platelets. We describe here a modified flow chamber system, established originally for platelet functional studies, that enables real-time observation of intra-thrombus fibrin accumulation during platelet thrombogenesis under flow conditions. ⋯ These observations were confirmed by perfusion of heparinized blood or blood from haemophilia patients with or without addition of activated factor VII. Thus, our experimental system provides visual evidence supporting the concept of "cell-based coagulation under whole blood flow", which might be the most physiologically relevant model of comprehensive thrombogenicity in vivo to date. This system promises to help formulate strategies for haemostatic management of congenital coagulation disorders as well as for antithrombotic therapy targeting fatal arterial thrombosis.
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Thrombosis research · Jan 2008
Platelet anaesthesia during extracorporeal circulation: differential effects of GP IIb/IIIa blockers on platelet activation marker P-selectin expression at hypothermia.
Blood contact with artificial surfaces of extracorporeal circulation (ECC) and hypothermia as applied in cardiac surgery cause platelet dysfunction possibly followed by bleeding complications. "Platelet anaesthesia" is a pharmacological strategy to protect platelets against ECC-induced damage using a GP IIb/IIIa blocker, which should be short acting to achieve maximal therapy control thereby avoiding post-ECC haemorrhage. However, GP IIb/IIIa blockers can paradoxically induce platelet activation, which may limit their efficiency as anti-platelet drugs. This in-vitro study investigated potentially platelet-activating effects of short-acting GP IIb/IIIa blockers during normothermic and hypothermic ECC. ⋯ Especially regarding its ultra-short half-life FK633 has the best properties for platelet protection during normothermic ECC. However, at hypothermia FK633 and eptifibatide induce platelet activation. In relation with "platelet anaesthesia" possible hypothermia-associated prothrombotic side effects of GP IIb/IIIa blockers should be considered.