1. Joint Diseases LaboratoryShriners Hospital for Crippled Children, Division of Surgical Research, Department of Surgery, McGill University, 1529 Cedar Avenue, Montreal, Quebec, Canada, H3G 1A6, +1-514 849 6208, +1-514 842 5581
2. Department of Human Metabolism and Clinical Biochemistry, University of Sheffield Medical School, Beech Hill Road, Sheffield, S10 2RX, UK