1. Division of Pediatrics, Department of Homeostatic Regulation and Development, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan
2. Faculty of Nursing, Social Welfare, and Psychology, Department of Nursing, Niigata Seiryo University, Niigata 951-8121, Japan
3. Department of Pediatrics, Niigata City General Hospital, Niigata 950-1197, Japan