1. Department of Clinical Physiology, Tokyo Metropolitan Institute of Gerontology, Tokyo-l73–0015, Japan
2. Department of Nutrition, Tokyo Metropolitan Institute of Gerontology, Tokyo-l73–0015, Japan
3. Third Department of Internal Medicine, Kobe University School of Medicine, Kobe-650, Japan;
4. Department of Molecular Genetics, Tohoku University School of Medicine, Sendai-980–8575, Japan; and
5. Research Institute, National Kyushu Cancer Center, Fukuoka-811–1395, Japan
6. Department of Gastroenterology, National Kyushu Cancer Center, Fukuoka-811–1395, Japan