[1] Univ Med Berlin, Med Klin MS Hepatol & Gastroenterol, Univ Klinikum Charite, Campus Virchow Klinikum, D-13353 Berlin, Germany
[2] Univ Klinikum Saarlandes, Homburg, Germany
[3] Christian Albrechts Univ Kiel Klinikum, Kiel, Germany
[4] Klinikum Heinrich Heine Univ, Dusseldorf, Germany
[5] Univ Zurich Hosp, Dept Gastroenterol & Hepatol, CH-8091 Zurich, Switzerland
[6] Med Univ Klin Eppendorf, Hamburg, Germany
[7] Univ Cologne, Med Klin 4, Cologne, Germany
[8] Med Univ Klin Freiburg, Freiberg, Germany
[9] Univ Munich, Klinikum Grosshadern, D-8000 Munich, Germany
[10] Ruhr Univ Bochum, St Josef Hosp, Med Univ Klin, D-4630 Bochum, Germany
[11] Univ Klinikum Heidelberg, Heidelberg, Germany
[12] Univ Wurzburg, Med Klin & Poliklin 2, Wurzburg, Germany
[13] Med Univ Klin 2, Bonn, Germany
[14] Univ Med Berlin, Inst Biometry & Klin Epidemiol, Charite, Berlin, Germany