1. Graduate School of Pharmaceutical Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai 980-8578, Japan, Kobe Pharmaceutical University, 4-9-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan, and Department of Pharmaceutical Sciences, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan