1. Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima-Shi 734-8551, Hiroshima, Japan
2. Department of Pediatrics, Faculty of Medicine, Kindai University, 377-2 Ohno-higashi, Osaka-Sayama 589-8511, Osaka, Japan
3. Ueda Child Clinic, 591-6 Tsubakihara, Hashimoto 648-0052, Wakayama, Japan
4. Department of Pediatrics, Kaizuka City Hospital, 3-10-20 Hori, Kaizuka 597-0015, Osaka, Japan
5. Department of Pediatrics, Sakai Sakibana Hospital, 2-7-1 Harayamadai, Minami-ku, Sakai 590-0132, Osaka, Japan
6. Department of Pediatrics, Kushimoto Municipality Hospital, 691-7, Sangodai, Kushimoto, Higashimuro 649-3510, Wakayama, Japan