[1] Hannover Med Sch, Dept Gastroenterol Hepatol & Endocrinol, D-3000 Hannover, Germany
[2] Bernhard Nocht Inst Trop Med, Hamburg, Germany
[3] Univ Kiel, Med Klin, Kiel, Germany
[4] Univ Saarland, Med Klin 2, D-6600 Saarbrucken, Germany
[5] Stadt Krankenhaus, Hildesheim, Germany