1. Clinic for Gastroenterology, Clinical Center Niš, 18000 Niš, Serbia.
2. Department of Internal Medicine, Faculty of Medicine, University of Niš, Zorana Ðinđića 81, 18000 Niš, Serbia.
3. Institute for Cardiovascular Diseases Sremska Kamenica, Put doktora Goldmana 4, 21208 Sremska Kamenica, Serbia.
4. Clinic for Cardiovascular and Transplantation Surgery, Clinical Center Niš, 18000 Niš, Serbia.
5. Clinic for Anesthesiology and Intensive Therapy, Department for Cardiosurgery, Clinical Center Nis, 18000 Niš, Serbia.
6. Clinical-Hospital Center, Pristina, Gracanica, Serbia.
7. Faculty of Medicine, University of Niš, Zorana Ðinđića 81, 18000 Niš, Serbia.
8. Department of Biochemistry, Faculty of Medicine, University of Niš, Zorana Ðinđića 81, 18000 Niš, Serbia.