[1] Univ Magdeburg, Clin Gastroenterol Hepatol & Infect Dis, D-39106 Magdeburg, Germany
[2] Clin Ctr Serbia, Inst Digest Dis, Clin Gastroenterol & Hepatol, Belgrade, Serbia Monteneg
[3] Inst Med Res, Dept Immunohistochem & Electron Microscopy, Belgrade, Serbia Monteneg
[4] First Univ Surg Hosp, Clin Ctr Serbia, Inst Digest Dis, Dept Esophageal & Gastr Surg, Belgrade, Serbia Monteneg