[1] VIENNA UNIV,DEPT MED 1,A-1010 VIENNA,AUSTRIA
[2] VIENNA UNIV,DEPT CHEMOTHERAPY,A-1010 VIENNA,AUSTRIA
[3] VIENNA UNIV,DEPT PATHOL,A-1010 VIENNA,AUSTRIA
[4] VIENNA UNIV,DEPT GASTROENTEROL 1,A-1010 VIENNA,AUSTRIA
[5] ST ANNA CHILDRENS HOSP,VIENNA,AUSTRIA