1. Centre for Health Protection, National Institute of Public Health and the Environment, Bilthoven, the Netherlands;
2. Department of Biochemistry, Lithuanian University of Health Sciences, Kaunas, Lithuania;
3. Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic;
4. Department of Clinical Biochemistry and Diagnostics, Regional Hospital of Pardubice, Pardubice, Czech Republic