[1] Univ Amsterdam, Acad Med Ctr, Dept Med Biochem, NL-1105 AZ Amsterdam, Netherlands
[2] Univ Amsterdam, Acad Med Ctr, Dept Pathol, NL-1105 AZ Amsterdam, Netherlands
[3] Leiden Univ, Dept Organ Chem, Gorleaus Inst, NL-2300 RA Leiden, Netherlands
[4] Genzyme Corp, Framingham, MA 01701 USA