1. Department of Gastroenterology, General Hospital of Northern Theater Command (Formerly General Hospital of Shenyang Military Area), Shenyang 110840, China
2. Postgraduate College, Jinzhou Medical University, Jinzhou 121000, China
3. Postgraduate College, Shenyang Pharmaceutical University, Shenyang 110016, China
4. Postgraduate College, Dalian Medical University, Dalian 116044, China
5. Departamento de Clínica Médica, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil