Clinical disorders that affect hemostasis and require replacement transfusions are common and life threatening disorders. Progress in developing better methods of defining new and more effective treatments for these disorders is complicated by the lack of mechanisms for coordinated studies. This application is in response to an RFA to participate in a Transfusion Medicine/Hemostasis Clinical Research Network. The resources available at the University of North Carolina at Chapel Hill for participation in a such a network are described, including the institutional commitment and excellence in the areas of hemostasis and transfusion medicine and the strong institutional emphasis on clinical research and the resources supporting clinical research. These resources provide well-defined study populations and access to large numbers of patients. Two clinical trials are proposed for the network. The first is a short term, multicenter study to use automated culture to monitor bacterial contamination of platelet concentrates under normal storage conditions. The aim of the study is to extend the shelf life of platelets. Platelet concentrates will be cultured on day 2 and the results of the culture used to extend the shelf life of sterile platelets from 5 to 7 days. The second study is a long term, multicenter, double-masked, placebo-controlled trial of recombinant VIla in patients with severe trauma and uncontrolled bleeding. The aim of the study is to determine the efficacy of recombinant factor Vlla as a hemostatic agent in severe trauma with bleeding that is refractory to standard replacement with fresh frozen plasma. The primary endpoint in the study is survival, determined at 24 h, 48 h, and 28 days. The secondary endpoints are the number of blood products infused, the number of days on ventilatory assistance, the number of days in the intensive care unit, the number of hospital days, and the extent of organ dysfunction.