1. University of Pittsburgh and the Institute for Transfusion Medicine, Pittsburgh, PA;
2. New England Research Institutes, Watertown, MA;
3. University of Iowa, Iowa City, IA;
4. Johns Hopkins University, Baltimore, MD;
5. University of Maryland, Baltimore, MD;
6. Brigham and Women's Hospital, Boston, MA; and
7. Puget Sound Blood Center and University of Washington Medical Center, Seattle, WA