1. Department of General Surgery, Franciszek Raszeja Memorial Hospital Poznan, Mickiewicza 2, 60-834 Poznan, Poland
2. Department of Rheumatology and Rehabilitation, Poznan University of Medical Sciences, 28 Czerwca 1956 Roku 135/147, 61-545 Poznan, Poland
3. Department of General Surgery, Medical Center H.C.P. Poznan, 28 Czerwca 1956 Roku 194, 61-485 Poznan, Poland
4. Veterinary Clinic, Kozanowska 40/16, 54-152 Wroclaw, Poland
5. Department of Swine and Small Ruminant Breeding, Faculty of Animal Breeding and Biology, University of Agriculture, Mickiewicza 24/28, 30-059 Krakow, Poland
6. Department of Endocrine, General and Vascular Surgery, Copernicus Memorial Hospital in Lodz, Medical University of Lodz, Pabianicka 62, 93-513 Lodz, Poland