1. Blood Research Laboratory, New England Medical Center Hospitals, and the Departments of Medicine and Physiology, Tufts University School of Medicine, Boston, Mass.
2. Jackson Veterans Administration Center, Jackson, Miss.; formerly Research Fellow, Blood Research Laboratory, New England Medical Center Hospitals, Fellow of the American Cancer Society, and Research Fellow in Medicine, Tufts University School of Medicine, Boston, Mass.
3. Tufts University School of Medicine, Boston, Mass.