1. Division of Medicine (P.V.R., J.P.B.), Guy’s, King’s and St. Thomas’ School of Medicine, London SE5 9PJ, United Kingdom
2. Clinical Sciences Centre (P.F.W., A.P.W.), University of Sheffield, Sheffield S5 7AU, United Kingdom
3. Faculty of Medicine (G.C.), Memorial University of Newfoundland, St. John’s, Newfoundland, Canada A1B 3V6