1. Nemours Cardiac Center, A.I. duPont Children's Hospital and Thomas Jefferson University, Wilmington, Delaware
2. Maryland Medical Research Institute, Baltimore, Maryland
3. Fox Chase Cancer Center, Philadelphia, Pennsylvania
4. Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
5. Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland
6. Department of Internal Medicine, New Jersey Medical School, Newark, New Jersey
7. Department of Nephrology, Children's Hospital, New Orleans, Louisiana
8. Kaiser-Permanente Center for Health Research, Portland, Oregon
9. Department of Preventive Medicine, Northwestern University Medical School, Chicago, Illinois
10. National Heart, Lung, and Blood Institute, Bethesda, Maryland