1. Center of Digestive Diseases; Internal Medicine Center Eppendorf; Hamburg Germany
2. Institute of Pathology, Lademannbogen; Hamburg Germany
3. Institute of Laboratory Medicine; Brandenburg Medical School; Brandenburg Hospital; Brandenburg Germany
4. Department of Medical Microbiology and Hygiene; University Hospital Freiburg; Freiburg Germany
5. Department of Medicine; Israelitic Hospital; Hamburg Germany
6. University Cancer Center, University Hospital; Hamburg Germany