1. Department of Otorhinolaryngology, University Hospital Ostrava, 708 52 Ostrava, Czech Republic
2. Faculty of Medicine, University of Ostrava, 703 00 Ostrava, Czech Republic
3. Department of Internal Medicine, City Hospital Frýdek-Místek, 738 01 Frýdek-Místek, Czech Republic
4. Department of Gastroenterology, Vítkovice Hospital Ostrava, 703 00 Ostrava, Czech Republic
5. Department of Oncology, University Hospital Ostrava, 708 52 Ostrava, Czech Republic