| 1990 – 2020 | University of Southern California, Los Angeles, United States |
| 1991 – 2019 | Keck School of Medicine of USC, Los Angeles, United States |
| 2013 | Esophageal Diagnostic Working Group, Chicago, United States |
| 2012 | University of Peradeniya, Kandy, Sri Lanka |
| 2010 | Departments of Surgery, Galveston, United States |
| 1990 – 2008 | University of California, Los Angeles, Los Angeles, United States |
| 2008 | University of Minnesota System, United States |
| 1999 – 2005 | USC Norris Comprehensive Cancer Center, Los Angeles, United States |
| 2002 | C.S. Mott Children’s Hospital, Ann Arbor, United States |
| 1999 | Cleveland Clinic Foundation, Cleveland, United States |
| 1991 – 1998 | Los Angeles County USC Medical Center, Los Angeles, United States |
| 1992 – 1998 | Memorial Sloan-Kettering Cancer Center, New York, United States |
| 1992 – 1998 | David Geffen School of Medicine at UCLA, Los Angeles, United States |
| 1995 – 1997 | Beth Israel Deaconess Medical Center, Boston, United States |
| 1993 – 1996 | University of Nebraska Medical Center, Omaha, United States |
| 1986 – 1995 | Creighton University School of Medicine, Omaha, United States |
| 1995 | Klinikum rechts der Isar der Technischen Universität München, Munich, Germany |
| 1995 | Ospedale Maggiore Policlinico Milano, Milan, Italy |
| 1995 | Ludwig-Maximilians-Universität München, Munich, Germany |
| 1995 | Università degli Studi di Milano, Milan, Italy |
| 1995 | Technical University of Munich, Munich, Germany |
| 1994 | KU Leuven– University Hospital Leuven, 3000 Leuven, Belgium |
| 1994 | KU Leuven, 3000 Leuven, Belgium |
| 1993 | McGill University Health Centre, Montreal General Hospital, Montreal, Canada |
| 1993 | Vanderbilt University, Nashville, United States |
| 1993 | Vanderbilt University Medical Center, Nashville, United States |
| 1993 | Massachusetts General Hospital, Boston, United States |
| 1985 – 1992 | Creighton University, Omaha, United States |
| 1992 | University of California, San Francisco, San Francisco, United States |
| 1992 | The University of Alabama at Birmingham, Birmingham, United States |
| 1992 | Julius-Maximilians-Universität Würzburg, Wurzburg, Germany |
| 1992 | Healthcare Consultation Center, Los Angeles, United States |
| 1992 | Southern CA University Medical Ctr., Los Angeles, United States |
| 1992 | Wake Forest School of Medicine, Winston Salem, United States |
| 1975 – 1991 | The University of Chicago, Chicago, United States |
| 1990 | The Department of Surgery, Meriden, United States |
| 1976 – 1986 | The University of Chicago Medicine, Chicago, United States |
| 1977 – 1986 | Walter Reed National Military Medical Center, Bethesda MD, United States |
| 1981 – 1986 | Uniformed Services University of the Health Sciences, Bethesda, United States |
| 1975 – 1985 | Pritzker School of Medicine, Chicago, United States |
| 1983 | Columbus Hospital, Chicago, Chicago, United States |
| 1978 – 1982 | Michael Reese Hospital, Chicago, United States |
| 1982 | Maastricht University, Maastricht, Netherlands |
| 1982 | University Hospital Maastricht, Maastricht, Netherlands |
| 1974 – 1981 | Tripler Regional Med Center, Honolulu, United States |
| 1974 | United States Navy, United States |
| 1974 | Tripler Army Med. Cent., Honolulu, United States |
| 1972 – 1973 | The Johns Hopkins Hospital, Baltimore, United States |
| 1973 | U.S. Army Pacific Regional Medical Command – Tripler Army Medical Center, Honolulu, United States |
| 1971 – 1972 | Johns Hopkins School of Medicine, Baltimore, United States |
| 1971 | Johns Hopkins Medical Institutions, Baltimore, United States |
