1. Fellow in Hepatology,University of Southern California, Department of Hepatology and Gastroenterology, 1986-1988

2. Fellow in Gastroenterology, University of Southern California, Department of Hepatology and Gastroenterology, 1988-1989

3. Staff (Associate Professor) in Gastroenterology, University of Southern California, Department of Hepatology and Gastroenterology, 1996-1997