1. Department of Pharmacology, Faculty and Graduate School of Dental Medicine, Hokkaido University, N13 W7, Sapporo, Hokkaido 060-8586, Japan
2. Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, 632-1 Mifuku, Izunokuni, Shizuoka 410-2321, Japan
3. Nikon Corporation, 2-15-3 Konan, Minato-ku, Tokyo 108-6290, Japan