1. From the University of South Florida College of Medicine, Department of Pediatrics, Division of Neonatology, Tampa, Florida;
2. Los Angeles County and University of Southern California School of Medicine, Division of Neonatal-Perinatal Medicine, Los Angeles, California;
3. Children's Mercy Hospital, Kansas City, Missouri;
4. University of Iowa Hospitals and Clinics, Iowa City, Iowa;
5. All Children's Hospital, St Petersburg, Florida; and
6. Ross Products Division, Abbott Laboratories, Columbus, Ohio.