Antithrombotic properties of the thromboxane A2/prostaglandin H2 receptor antagonist S18886 on prevention of platelet-dependent cyclic flow reductions in dogs.

A potent thromboxane A2/PGH2 (TP)-receptor antagonist, S18886, was evaluated for its antithrombotic property in a dog model of acute periodic platelet-mediated thrombosis in stenosed coronary arteries with endothelial damage. After thrombosis had been obtained in 11 dogs, S18886 (300 microg/kg bolus) was administered IV. Heart rate, systemic blood pressure, and coronary blood flow were continuously recorded.

Utility of point-of-care diagnostic testing in patients with chest pain and suspected acute myocardial infarction.

Advances over the past few years have led to the use of hand-held point-of-care diagnostic tests to expedite testing for cardiac enzymes indicative of acute myocardial infarction. Although cardiac enzymes such as troponin I and CKMB are reliable markers of acute myocardial infarction, they cannot be detected until several hours after the insult and patients are often tested for up to 24 hours before acute myocardial infarction can be ruled out. A better understanding of early events in thrombus formation, specifically the role of P-selectin in platelet aggregation, should soon allow even more rapid diagnosis and improve pharmacological treatment.

Role of inflammatory mediators in thrombogenesis.

The role of inflammation in cardiovascular disease and especially in thrombogenesis has become increasingly recognized as an important component of the overall disease process. Plaque rupture promotes activation of the inflammatory response and increased expression of tissue factor (TF), which in turn acts as one of the major initiators of extrinsic coagulation. It is becoming apparent that the expression of TF on endothelial cells, underlying smooth muscle cells and monocytes is regulated, in part, by proinflammatory cytokines including tumor necrosis factor and IL-1.