1. Laboratories of Biochemistry and Toxicology, Wageningen University, Dreijenlaan 3, 6703 HA, and Tuinlaan 5, 6703 HE Wageningen, The Netherlands, Faculty of Commodity Science, Poznan University of Economics, al. Niepodleglosci 10, 60-967 Poznan, Poland, Institute of Biochemistry, Mokslininku 12, Vilnius 2600, Lithuania, and Unit of Biochemical Toxicology, Wallenberg Laboratory, Department of Biochemistry, Stockholm University, Stockholm, Sweden