1. Department of Biochemistry (I), Jikei University School of Medicine, Minato-ku, Tokyo 105, Japan
2. Department of Research Laboratory, SRL, Inc., Komiya-cho, Hachioji-shi, Tokyo 192, Japan
3. Department of Internal Medicine (II), Jikei University School of Medicine, Minato-ku, Tokyo 105, Japan
4. Department of Internal Medicine (Kashiwa Hospital), Jikei University School of Medicine, Minato-ku, Tokyo 105, Japan
5. Department of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060, Japan