1. Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565, Japan.
2. Department of Internal Medicine, The Branch Hospital, Nagoya University School of Medicine, Nagoya 461, Japan.
3. Department of Pediatrics, Gifu University School of Medicine, Gifu 500, Japan.
4. Department of Internal Medicine, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565, Japan.