1. Department of Bacteriology; Osaka City University Medical School; Osaka Osaka 545-8585 Japan
2. Third Department of Internal Medicine; Osaka City University Medical School; Osaka Osaka 545-8585 Japan
3. Department of Health and Epidemiology; Osaka City Institute of Public Health and Environmental Sciences; Osaka Osaka 543-0026 Japan
4. Research Institute for Traditional Sino-Japanese Medicines; Toyama Medical and Pharmaceutical University; Toyama 930-0194 Japan