[1] Landenskrankenhaus Salzburg, Salzburg, Austria
[2] Univ Childrens Hosp Basel, Basel, Switzerland
[3] Univ Saarland, Cent Lab, Homburg, Germany
[4] Univ Bonn, Inst Nutr Sci, D-5300 Bonn, Germany
[5] Otto Von Guericke Univ, Inst Clin Chem, Magdeburg, Germany
[6] Karl Franzens Univ Graz, Dept Ophthalmol, LKH Graz, Graz, Austria