1Research Center on Aging, Immunology Program, Geriatric Division, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec
2Departments of Pathology and Molecular Medicine and Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
Reprints or correspondence: Dr. Mark Loeb, Dept. of Pathology and Molecular Medicine, McMaster University, MDCL 3200, 1200 Main St. W., Hamilton, Ontario L8N 3Z5, Canada ([email protected]).