1. Department of Histology & Embryology, Faculty of Medicine, Charles University, Karlovarska 48, Plzen, Czech Republic
2. Department of Obstetrics & Gynecology, University Hospital, Faculty of Medicine, Charles University, Alej Svobody 80, Plzen, Czech Republic
3. Biomedical Centre, Faculty of Medicine, Charles University, Plzen, Czech Republic
4. Department of Pathology, University of Louisville, 511 S Floyd, Louisville, KY 40202, USA