[1] Univ Iowa, Dept Internal Med, Iowa City, IA 52242 USA
[2] Univ Iowa, Dept Epidemiol, Iowa City, IA 52242 USA
[3] Pacific Neurosci Inst, Santa Monica, CA USA
[4] Oklahoma Med Res Fdn, Aging & Metab Res Program, Oklahoma City, OK USA
[5] Univ Oklahoma, Hlth Sci Ctr, Dept Cell Biol, Oklahoma City, OK USA
[6] Corinne Goldsmith Dickinson Ctr Multiple Sclerosis, Icahn Sch Med Mt Sinai, Dept Neurol, New York, NY USA
[7] Univ Iowa, Dept Neurol, Iowa City, IA USA