1. Cancer Prevention Division, National Cancer Center Research Institute, 1-1, Tsukiji 5-chome, Chuo-Ku, Tokyo 104-0045, Japan, Department of Public Health, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan, and School of Pharmaceutical Science, University of Shizuoka, 52-1, Yada, Shizuoka 422-8526, Japan