1. Department of Pediatrics, Jikei University School of Medicine Nishishinbashi, Mintoku, Tokyo, 105, Japan
2. Department of Pediatrics, Kanagawa Prefectural Atsugi Hospital, 1-16-36 Mizuhiki, Atsugi, 243, Japan
3. Department of C1inical Laboratory Science, Yamaguchi University School of Medicine, 1144 Kogushi, Ube, 755, Japan