1. Department of Nutrition (M.F., V.W., M.T.C.), University Park, Pennsylvania 16802
2. Immunopathogenesis Section (T.A.W.), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
3. Department of Biology (M.A.M., J.E.W.), Notre Dame University, South Bend, Indiana 46556