1. Yale University School of Medicine (S.E.P., P.D., R.C.V.), New Haven, Connecticut 06520
2. Department of Veterans Affairs, Pittsburgh, Pennsylvania 15213
3. The Department of Cell Biology (R.L.S.), The University of Minnesota, Minneapolis, Minnesota 55455
4. The Division of Endocrinology (A.G.-O., A.F.S.), The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213