[1] Hirosaki Univ, Grad Sch Med, Dept Pediat, Hirosaki, Aomori, Japan
[2] Nagoya Univ, Sch Med, Dept Pediat, Nagoya, Aichi, Japan
[3] Nagoya Univ, Sch Med, Dept Infect Dis, Nagoya, Aichi, Japan
[4] Jichi Med Univ, Div Funct Genom, Shimotsukeshi, Tochigi, Japan