Platelet function in baboons and humans - A comparative study of whole blood using impedance platelet aggregometry (Multiplate®).

Background: Platelets play a pivotal role in coagulation, inflammation and wound healing. Suitable animal models that have the potential to mimic human platelet function are limited. The objective of the current study was to compare platelet aggregation response in the whole blood of baboons and humans using impedance aggregometry.

Influence of High Polyphenol Beverage on Stress-Induced Platelet Activation.

Objectives: Platelets are playing a crucial role in acute cardiovascular events. We investigated if physical stress activates platelets and whether this activation can be inhibited by a polyphenol-enriched diet.

Methods: Blood samples were taken from a total of 103 athletes three weeks before, one day before, immediately as well as 24 hours and 72 hours after a marathon run.

A detailed examination of platelet function inhibition by nitric oxide in platelet-rich plasma and whole blood.

Background: The question of whether novel instruments such as multiple electrode aggregometry (MEA) can be used for measurement of the effects of nitric oxide (NO) on platelets (PLTs) has not been examined.

Methods: Therefore, we compared the effects of NO concentrations (1, 10, and 100 microM) on the PLT aggregation response to ADP, arachidonic acid (AA), collagen, ristocetin, and thrombin receptor-activating peptide 6 (TRAP6) using light transmission aggregometry (LTA) and multiple electrode aggregometry (MEA) and examined the effects of NO using the platelet function analyzer (PFA)-100.

Results: The response of PLTs to ADP and AA was strongly inhibited by all NO concentrations in LTA and MEA.

Residual platelet activation through protease-activated receptors (PAR)-1 and -4 in patients on P2Y12 inhibitors.

Background: Dual antiplatelet therapy with aspirin and thienopyridines has improved outcomes of patients after coronary stent implantation. However, current knowledge suggests that thrombin generation is not affected by inhibition of the P2Y12 receptor, and therefore, platelet activation may still occur.

Methods: The response to agonists specific for protease-activated receptors (PAR)-1 and -4 was tested by multiple electrode impedance aggregometry in 82 patients on stable doses of clopidogrel or prasugrel, and in 55 healthy controls.

Haemostatic therapy in coronary artery bypass graft patients with decreased platelet function: comparison of fibrinogen concentrate with allogeneic blood products.

Background: Patients undergoing coronary artery bypass grafting (CABG) are at risk of postoperative bleeding because of decreased platelet function and cardiopulmonary bypass (CPB)-induced haemostatic impairment. Fibrinogen concentration decreases by 34-42% of the preoperative level by the end of CPB. An inverse relationship between perioperative plasma fibrinogen levels and postoperative bleeding has been reported in CABG patients.