Institution: | (1) Present address: The Kitasato Institute Bioiatric Center, Shirogane, Minato-ku, 108 Tokyo, Japan;(2) Department of Hygiene, Dokkyo University School of Medicine, Mibu, 321-02 Tochigi, Japan;(3) Central Research Laboratories, Nippon Zenyaku Kogyo Co., Ltd., Koriyama, 969-05 Fukushima, Japan |