1. Department of Experimental Animals, Center for Integrated Research in Science, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan
2. Department of Fundamental Nursing, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan
3. Department of Laboratory Animal Medicine, Osaka University, Medical School, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan