1. Department of Biotechnology, University of Turku, Tykistökatu 6A, FIN-20520 Turku, Finland
2. Laboratory and
3. Department of Internal Medicine, Oulu University Hospital, PL 500, FIN-90029 OYS, Finland
4. Department of Clinical Chemistry, Helsinki University Central Hospital, Haartmaninkatu 2, FIN-00290 Helsinki, Finland