1. Department of Medicine, West Los Angeles VA Medical Center and UCLA School of Medicine, Los Angeles, California 90095
2. Department of Medicine, West Los Angeles VA Medical Center and UCLA School of Medicine, Department of Molecular and Medical Pharmacology, UCLA School of Medicine, Los Angeles, California 90095
3. UCLA School of Public Health, Los Angeles, California 90095
4. Department of Neurology, UCLA School of Medicine, Los Angeles, California 90095