1. Central
Research Laboratories, Kissei Pharmaceutical Co., Ltd., 4365-1, Kashiwabara,
Hotaka, Azumino, Nagano 399-8304, Japan
2. Faculty
of Pharmaceutical Science and §Center for Research and Education on Drug Discovery, Hokkaido University, Kita-12, Nishi-6, Kita-Ku, Sapporo 060-0812, Japan