Ko Ichihashi1,2* and Mariko Momoi2
1Department of Pediatrics, Ibaraki Prefectural Central Hospital, 6528 Koibuchi Kasama, Ibaraki, 309-1793 Japan.
2Department of Pediatrics, Jichi Medical University, 3311- 1 Minamikawachi Shimotsuke, Tochigi, 329-0498 Japan.
