1. Department of Pharmacology, School of Life Dentistry at Tokyo; Nippon Dental University; 1-9-20 Fujimi, Chiyoda-ku Tokyo 102-8159 Japan
2. Faculty of Health Sciences, Department of Radiological Technology; Butsuryo College of Osaka; Otorikitamachi 3-33, Nishi-ku, Sakai Osaka 593-8328 Japan