1. Department of Gastroenterology Medical School of National and Kapodistrian University of AthensGeneral Hospital of Athens “Laiko” Athens Greece
2. Department of Physiology Medical School of National and Kapodistrian University of Athens Athens Greece
3. Department of Clinical Therapeutics Medical School of National and Kapodistrian University of Athens“Alexandra” General Hospital of Athens Athens Greece
4. Institute for Clinical Chemistry and Laboratory Medicine University Clinic Carl Gustav CarusTechnische Universität Dresden Dresden Germany