Hiroyuki Wakiguchi1, Syuji Takei2, Yoshifumi Kawano3. 1. Department of Pediatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan; Department of Pediatrics, Yamaguchi University Graduate School of Medicine, Ube, Japan. Electronic address: hiroyuki@yamaguchi-u.ac.jp. 2. Department of Pediatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan; School of Health Science, Faculty of Medicine, Kagoshima University, Kagoshima, Japan. 3. Department of Pediatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.