1. Institute for Molecular and Cellular Biology, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565, Japan.
2. Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565, Japan.
3. Biotechnology Research Laboratory, Tosoh Corporation, 2743-1 Hayakawa, Ayase, Kanagawa 252, Japan.
4. Department of Medicine Ill, Osaka University Medical School, 1-1-50 Fukushima, Fukushima- ku, Osaka 553, Japan.