1. Center for Health Protection, National Institute of Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, The Netherlands
2. Department of Biochemistry, Medical Academy, Lithuanian University of Health Sciences, A. Mickeviciaus 9, 44307 Kaunas, Lithuania
3. Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice, Czech Republic
4. Department of Clinical Biochemistry and Diagnostics, Regional Hospital of Pardubice, Kyjevska 44, 53203 Pardubice, Czech Republic