1. Experimental Endoscopy, Internal Medicine, University Hospital Schleswig-Holstein, Kiel, Germany
2. University College London, London, UK
3. Department of Gastroenterology, Texas Tech University of Health Sciences Center, Lubbock, Texas, USA
4. Homerton University Hospital, London, UK
5. Kings College Hospital, London, UK
6. Loeffler Institute of Animal Breeding, Mariensee, Germany