[1] Kobe Univ, Dept Pediat, Grad Sch Med, Chuo Ku, Kobe, Hyogo 6500017, Japan
[2] Hyogo Prefectural Kobe Childrens Hosp, Dept Nephrol, Hyogo, Japan
[3] Kakogawa Municipal Hosp, Dept Pediat, Hyogo, Japan
[4] Wakayama Med Univ, Dept Pediat, Wakayama, Japan
[5] Himeji Red Cross Hosp, Dept Pediat, Hyogo, Japan