Heart rate , respiratory rate , rectal temperature , CBC variables , plasma fibrinogen concentration , serum tumor necrosis factor - concentration , plasma von Willebrand factor concentration , and measures of platelet activation ( including ADP - and collagen-induced platelet aggregation and closure times , thrombelastography variables , and results of flow cytometric detection of platelet membrane P-selectin , phosphatidylserine , and microparticles ) were determined at various times before and after LPS administration by investigators unaware of the treatment groups .