1. Division of Gastroenterology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki 701-0192 Japan
2. Department of Surgery, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
3. Department of Cell Biology, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
4. Tissue Engineering Research Center, The National Institute of Advanced Industrial Science and Technology, 1-1-4 Higashi, Tsukubashi, Ibaragi 305-8562, Japan
5. Animal Center for Medical Research, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
6. Department of Immunochemistry, Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan