1. From the Department of Medicine (S.M.M., T.R.K.), University of Pittsburgh, PA.
2. Division of Clinical Pharmacology, Department of Medicine, and Department of Molecular Physiology and Biophysics Vanderbilt University, Nashville, TN (A.K.).
3. Department of Cell Biology (T.R.K.), University of Pittsburgh, PA.
4. Department of Pharmacology and Chemical Biology (T.R.K.), University of Pittsburgh, PA.