1. Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, P. R. China
2. Hubei Clinical Center and Key Laboratory for Intestinal and Colorectal Diseases, Wuhan, Hubei Province, P. R. China
3. Stephenson Cancer Center and Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
4. Department of Critical Care Medicine, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, P. R. China