The Prosorba column for treatment of refractory rheumatoid arthritis: A randomized, double-blind, sham-controlled trial

David T. Felson, Michael P. La Valley, Andrew R. Baldassare, Joel A. Block, Jacques R. Caldwell, Grant W. Cannon, Chad Deal, Stephen Evans, Roy Fleischmann, R. Michael Gendreau, E. Robert Harris, Eric L. Matteson, Sanford H. Roth, H. Ralph Schumacher, Michael H. Weisman, Daniel E. Furst