1. Canadian Red Cross Society, Blood Services, Hamilton, Ontario, L8N 1H8 Canada
2. McMaster University, Department of Pathology, HSC 3N26, 1200 Main St. West, Hamilton, Ontario, L8N 3Z5 Canada
3. St. Michael's Hospital and Department of Medicine, University of Toronto, Toronto, Ontario, M5B 1W8 Canada
4. State of New York Department of Health, Albany, New York, NY 12201, U.S.A.