1. MRC Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, U.K.
2. Metabolic Physiopathology Research Group, Department of Basic Medical Sciences, Faculty of Medicine, Lleida University, Lleida 25198, Spain
3. Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, U.S.A.,
4. Department of Vascular Biology, SmithKline Beecham Pharmaceuticals, Harlow, Essex CM19 5AW, U.K.