This volume contains a collection of essays by selected authors who are active in the field of blood substitutes research or closely allied disciplines. These essays were delivered as lectures by the authors at the second annual "Current Issues in Blood Substitute Research and Development - 1995" course sponsored jointly by the Departments of Medicine and Bioengineer ing, University of California, San Diego, the National Institutes of Health (NHLBI), and the U.S. Army on March 30, 31, and April 1, 1995 in San Diego. This course had three goals: to present fundaniental discussions of scientific issues critical to further development of artificial oxygen carriers, to provide academicians a forum to discuss their current research, and to provide the companies involved in developing products the opportunity to update the audience on their progress. The organization owes much to the solicited comments of the attendees of the 1994 course. We would like especially to thank the U.S. Army, particularly through the efforts of COL John Hess, who provided significant funding to make publication of this volume possible. In addition, a number of the participating companies provided additional financial support to offset the costs of the course. These include Alliance Pharmaceutical Corp., Hemosol, Nippon Oil and Fat, Northfield Laboratories, and Ortho Biotech."