[1] Department of Pediatrics,
[2] School of Medicine,undefined
[3] Chiba University,undefined
[4] 1-8-1,undefined
[5] Inohana,undefined
[6] Chuo-ku,undefined
[7] Chiba-shi,undefined
[8] Chiba,undefined
[9] 260-8670,undefined
[10] Japan e-mail: shinji@med.m.chiba-u.ac.jp Tel.: +81-43-2262144,undefined
[11] Fax: +81-43-2262145,undefined
[12] Department of Pediatric Surgery,undefined
[13] School of Medicine,undefined
[14] Chiba University,undefined
[15] Chiba,undefined
[16] Japan,undefined