1. Department of Histology and Embryology, University of Medical Sciences, Poznań, Poland
2. Department of Histology, University of Medical Sciences, Wrocław, Poland
3. Department of Clinical Pathomorphology, University of Medical Sciences, Poznań, Poland
4. Department of Health Prophylaxis, University of Medical Sciences, Poznań, Poland
5. Ward of Infectious Diseases, J. Struś Hospital, Poznań, Poland