Randomised double-blind placebo-controlled study of interferon beta-1a in relapsing/remitting multiple sclerosis. PRISMS (Prevention of Relapses and Disability by Interferon beta-1... by Ebers, G, Rice, G, Lesaux, J, Paty, D, Oger, J, Li, D, Beall, S, Devonshire, V, Hashimoto, S, Hooge, J, Kastrukoff, L, Krieger, C, Mezei, M, Seland, P, Vorobeychi, G, Morrison, W, Nelson, J, Freedman, MS, Chrisie, S, Nelson, R, Rabinovitch, H, Freedman, C, Hartung, H, Rieckmann, P, Archelos, J