1. Musculoskeletal Disease Center (K.E.G., J.E.W., S.M.), Jerry L. Pettis Veterans Affairs Medical Center, Loma Linda, California 92357;
2. Department of Medicine (J.E.W., D.J.B., S.M.), Loma Linda University, Loma Linda, California 92354;
3. German Cancer Research Center (L.F., P.A.), D-69120 Heidelberg, Germany