1. Laboratory Animal Facility, School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan
2. Laboratory Animal Facilities, Research Center for Medical Sciences, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-0003, Japan
3. College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0813, Japan