Jonathan Cowman

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We report the development and demonstration of an assay that distinguishes the pharmacological effects of two widely used antiplatelet therapies, aspirin (COX-1 inhibitor) and clopidogrel (P2Y12 inhibitor). Whole blood is perfused through a low-volume microfluidic device in contact with a well-characterized (ellipsometry, atomic force microscopy)(More)
BACKGROUND Activation of the platelet-specific collagen receptor, glycoprotein (GP) VI, induces intracellular reactive oxygen species (ROS) production; however the relevance of ROS to GPVI-mediated platelet responses remains unclear. OBJECTIVE The objective of this study was to explore the role of the ROS-producing NADPH oxidase (Nox)1 and 2 complexes in(More)
Age is a risk factor for cardiovascular disease (CVD), however the effect of age on platelet function remains unclear. Ideally, platelet function should be assayed under flow and shear conditions that occur in vivo. Our study aimed to characterise the effect of age on platelet translocation behaviour using a novel flow-based assay that measures platelet(More)
We report the case of a man aged 19 who sustained an anterior dislocation of the shoulder with a fracture of the greater tuberosity, and a fracture of the shaft of the same humerus. Open reduction and internal fixation of the shaft fracture was carried out followed by closed manipulation of the dislocation. He recovered full function of the shoulder and(More)
While critically important, the platelet function at the high shear rates typical of the microcirculation is relatively poorly understood. Using a large scale Stokes flow simulation, Zhao et al. recently showed that RBC-induced velocity fluctuations cause platelets to marginate into the RBC free near-wall region [Zhao et al., Physics of Fluids, 2012, 24,(More)
The imaging of shear-mediated dynamic platelet behavior interacting with surface-immobilized von Willebrand factor (vWF) has tremendous potential in characterizing changes in platelet function for clinical diagnostics purposes. However, the imaging output, a series of images representing platelets adhering and rolling on the surface, poses unique,(More)
Platelet function in pregnancy is poorly understood. Previous studies of platelet function in pregnancy have used non-physiological assays of platelet function with conflicting results. This study using a physiological assay of platelet function investigated platelet interactions with von Willebrand Factor (VWF) in blood from healthy pregnant women and(More)
Background Antiplatelet agents, such as aspirin and P2Y12 inhibitors, are essential in the secondary prevention of cardiovascular disease [1]. Despite effective treatment with these drugs, many patients still suffer ischemic events. This suggests the need for additional antiplatelet therapy. The P2Y1 receptor is a seven transmembrane G protein coupled(More)
BACKGROUND The management of ipsilateral femoral shaft fractures after hemiarthroplasty is controversial. METHODS Fifteen patients (average age 82.4 +/- 8 years) with ipsilateral femoral shaft fractures after uncemented hemiarthroplasty were treated by closed reduction and Ender nailing. Under radiographic control, closed reduction was attempted. If not(More)
Essentials It is unclear if platelet function differs between preterm and full-term neonates. Platelet behavior was characterized using a flow-based assay on von Willebrand Factor (VWF). Preterms had increased platelet interaction with VWF and glycoprotein Ibα expression. Platelets from preterm neonates behave differently on VWF compared to full-term(More)