1. Departments of Physiology (A.T.C.) New Orleans, Louisiana;
2. Department of Medicine, University of Tennessee and Research Service, Veterans Administration Medical Center (D.R., M.B.A.), Memphis, Tennessee 38104
3. Tulane University and Department of Medicine, Louisiana State University (J.K.K.), New Orleans, Louisiana;
4. Departments of Medicine (J.F. and D.H.C.), New Orleans, Louisiana;