1. Evangelisches Krankenhaus Köln‐Kalk, University of Cologne, Germany,
2. Castra Regina Centre, Regensburg, Germany,
3. Laboratory of Gastroenterology, Medical Department, Prague, Czech Republic,
4. II. University Clinic, Charles University Hradec Kralove, Czech Republic,
5. Universittsklinik fr Innere Medizin, Gastroenterologie und Hepatologie, University of Innsbruck, Austria,
6. Pathological Institute, Bayreuth, Germany.