1. Departments of Cardiology, Children's Hospital Boston,
2. Center for Biostatistics in AIDS Research, Harvard School of Public Health, Boston, Massachusetts
3. Department of Medicine, Children's Hospital Boston
4. Division of Hematology, Children's Hospital Boston
5. Laboratory Medicine, Children's Hospital Boston
6. Division of General Pediatrics, Department of Pediatrics, Children's Hospital at Dartmouth, Dartmouth Medical School, Hanover, New Hampshire