1. Department of Endocrinology & Metabolism, Clinical Research Institute, Kanagawa Children's Medical Center, Yokohama 232-8555, Japan
2. Department of Pediatrics, Matsuyama Red Cross Hospital, Matsuyama 790-8524, Japan
3. Department of Pediatrics, Yokohama Municipal Citizen's Hospital, Yokohama 240-8555, Japan
4. Department of Pediatrics, Medical School Keio University, Tokyo 160-8582, Japan