[1] Nagoya Univ, Dept Pediat, Grad Sch Med, Nagoya, Aichi 4648601, Japan
[2] Japanese Red Cross Nagoya 1st Hosp, Dept Pathol, Nagoya, Aichi, Japan
[3] Ibaraki Childrens Hosp, Mito, Ibaraki, Japan
[4] Sapporo Hokuyu Hosp, Dept Pediat, Sapporo, Hokkaido, Japan
[5] Hirosaki Univ, Dept Pediat, Grad Sch Med, Hirosaki, Aomori, Japan
[6] Tokai Univ, Sch Med, Dept Pediat, Isehara, Kanagawa 25911, Japan
[7] Kyushu Univ, Dept Pediat, Grad Sch Med Sci, Fukuoka 812, Japan
[8] Toho Univ, Dept Pediat, Sch Med, Tokyo, Japan