1. Department of Surgery, University of Oslo, Norway.
2. Department of Surgery, Weill Medical College of Cornell University, New York.
3. Department of Surgery, Ludwig-Maximilians Universitat, Munich, Germany.
4. Department of Surgery, University of Pittsburgh, Pittsburgh.
5. Department of Surgery, University of New Mexico, Albuquerque, NM.
6. Department of Surgery, Nordwest-Krankenhaus, Sande, Germany.