[1] Univ Belgrade, Sch Med, Clin Ctr Serbia, Inst Neurol, YU-11000 Belgrade, Yugoslavia
[2] Clin Ctr Serbia, Inst Med Biochem, YU-11000 Belgrade, Yugoslavia
[3] Inst Biol Res, YU-11000 Belgrade, Yugoslavia
[4] Clin Ctr Serbia, MRI Ctr, YU-11000 Belgrade, Yugoslavia
[5] Univ Belgrade, Sch Med, Inst Biostat Publ Hlth & Res Med, YU-11000 Belgrade, Yugoslavia
[6] Univ Belgrade, Sch Med, Inst Microbiol & Immunol, YU-11000 Belgrade, Yugoslavia