1. Department of Surgery, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
2. Division of Gastroenterology I, Department of Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192 Japan
3. Animal Center for Medical Research, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
4. Medical Products Development Department, Kuraray Medical Co., 1621 Sakazu, Kurashiki, Okayama 710-8622, Japan
5. Tissue Engineering Research Center, The National Institute of Advanced Industrial Science and Technology. 1-1-4 Higashi, Tsukubashi, Ibaragi 305-8562, Japan