From the University of California San Francisco (Drs. Orland, Engstrom, and Murphy); Blood Centers of the Pacific (Drs. Orland and Murphy), San Francisco; City of Hope National Medical Center (Dr. Fridey), Duarte, CA; Hoxworth Blood Center and University of Cincinnati (Dr. Sacher), OH; Oklahoma Blood Institute (Dr. J.W. Smith), Oklahoma City; American Red Cross Blood Services, Chesapeake Region (Dr. Nass), Baltimore, MD; American Red Cross Blood Services, Southern California Region (Dr. Garratty),... (At 2003-12-09)