1. Department of Abdominal Surgery, Faculty of Medicine, Catholic University of Leuven, B-3000 Leuven, Belgium
2. Department of Biochemistry, Faculty of Medicine, Catholic University of Leuven, B-3000 Leuven, Belgium
3. Dept. of Abdominal Surgery, U.Z. Gasthuisberg, B-3000 Leuven, Belgium
4. Department of Pathology, Faculty of Medicine, Catholic University of Leuven, B-3000 Leuven, Belgium