1. Department of Pathology, Shandong Medical College, Ji'nan, P.R. China;
2. Department of Physiology, Shandong Medical College, Ji’nan, P.R. China;
3. Department of Pharmacy, Shandong Medical College, Ji’nan, P.R. China;
4. Department of Gastroenterology, 401 Hospital of the Chinese People’s Liberation Army, Qingdao, P.R. China