[1] Department of Pediatrics,
[2] Keio University School of Medicine,undefined
[3] 35 Shinanomachi,undefined
[4] Shinjuku-ku,undefined
[5] Tokyo 60-8582,undefined
[6] Japan e-mail: t-ishii@med.keio.ac.jp,undefined
[7] Tel.: +81-3-33531211,undefined
[8] Fax: +81-3-53791978,undefined