1. Department of Hygiene and Second Department of Surgery, Miyazaki Medical College, Miyazaki 889-16, Japan, Primate Research Institute, Kyoto University, Aichi 484, Japan, Department of Second Medical Biochemistry, School of Medicine, Ehime University, Onsen-gun, Ehime 791-02, Japan, and Department of Bioengineering, School of Engineering, Yokohama National University, Yokohama, Kanagawa 240, Japan