1. Liver Research Unit, Medica Sur Clinic & Foundation, Faculty of Medicine National Autonomous University of Mexico Mexico City Mexico
2. Department of Gastroenterology, Xinhua Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
3. Department of Endemic Medicine, Faculty of Medicine Helwan University Cairo Egypt
4. Departamento de Gastroenterología y Endoscopia Digestiva, Hospital de Clínicas Universidad Nacional de Asunción Asunción Paraguay