1. 1 Department of Physiology Medical and Health Science Centre, University of Debrecen H-4012 Debrecen, P.O. Box 22, Hungary
2. 2 Department of General and Thoracic Surgery, Semmelweis Teaching Hospital H-3529 Miskolc, Csabai kapu 9-11, Hungary
3. 3 Department of Pathology, Semmelweis Teaching Hospital Miskolc, Hungary
4. 4 Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Medical and Health Science Centre Debrecen, Hungary
5. 5 Department of General and Thoracic Surgery, Semmelweis Teaching Hospital H-3529 Miskolc, Csabai kapu 9-11, Hungary
6. 6 Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Medical and Health Science Centre Debrecen, Hungary