1. Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
2. Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
3. Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington 98195
4. Department of Pathology, University of Washington, Seattle, Washington 98195, USA