1. Department of Gastroenterology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
2. Department of Gastroenterology, The First People's Hospital of Changde City, Changde, Hunan 415000, P.R. China
3. Department of General Practice, The First People's Hospital of Lianyungang, Lianyungang, Jiangsu 222000, P.R. China
4. Department of Endoscopy Center, Hunan Cancer Hospital, Changsha, Hunan 410000, P.R. China
5. Institute of Medical Sciences, Xiangya Hospital, Central South University, Changsha, Hunan 410000, P.R. China
6. Faculty of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410000, P.R. China
7. Department of Nephropathy, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China