This Program Project proposes to provide optimal conditions and facilities for the research of a relatively large group of investigators with special interests and experience in the pathophysiology of blood coagulation and hemostasis. The investigators represent most of the various basic medical science and clinical disciplines. The long-term goals of the project are the understanding, effective treatment and prophylaxis of hemorrhagic diseases. Many approaches are being used to gain significant information. These include isolation and purification of clotting factors, studies of calcium and lipid binding using NMR and fluorescence methods, organ perfusions, ablation, and transplantation to determine sites of synthesis, immunologic procedures to identify cells of synthesis and structural features of the coagulant proteins, genetic investigations to locate sites of genetic information and to clarify biochemical and physiological processes, and cellular clotting at the ultramicroscopic level.