1. Departments of Pediatrics and Medicine, New England Medical Center Hospitals, and Tufts University School of Medicine, Boston, Mass. and the Department of Medicine, University of Puerto Rico, San Juan, Puerto Rico.
2. Hematologist, New England Medical Center Hospitals; Asristant Professor of Pediatrics, Tufts University School of Medicine; Established Investigator, American Heart Association.
3. Department of Medicine, University of Puerto Rico, San Juan, Puerto Rico.
4. New England Medical Center Hospitals. Associate Professor of Pediatrics, Tufts University School of Medicine.