1. Liver Clinic; Department of Gastroenterology; Instituto Nacional de Ciencias Médicas y Nutrición “Salvador Zubirán”; México D.F Tlalpan México
2. Division of Gastroenterology and Hepatology; University of Arkansas for Medical Sciences (UAMS); Little Rock AR USA
3. Department of Neurology; Instituto Nacional de Ciencias Médicas y Nutrición “Salvador Zubirán”; México D.F Tlalpan México
4. Department of Internal Medicine I; University of Bonn; Bonn Germany