1. Nano and Molecular Systems Research Unit, 90014 University of Oulu, PO Box 3000, Finland
2. Biocenter Oulu, 90014 University of Oulu, PO Box 5000, Finland
3. Research Unit of Clinical Medicine and Medical Research Center, Oulu University Hospital and University of Oulu, 90014 Oulu, Finland
4. Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, 40530 Gothenburg, Sweden
5. Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Sweden and Department of Clinical Chemistry, Sahlgrenska University Hospital, 41345 Gothenburg, Sweden
6. Department of Paediatrics and Adolescent Medicine, Paediatric Neurology Unit, Oulu University Hospital, 90029 Oulu, Finland