Medical Progress

From the Department of Medicine, Pulmonary Division and Occupational-Environmental Medicine Section, National Jewish Medical and Research Center (L.S.N., C.S.R.); and the Department of Medicine, Division of Pulmonary Science and Critical Care Medicine (L.S.N., C.S.R., L.A.M.), and the Department of Preventive Medicine and Biometrics (L.S.N., C.S.R.), University of Colorado Health Sciences Center -- both in Denver. Address reprint requests to Dr. Newman at the National Jewish Medical and Research Center, 1400 Jackson St., Rm. G-010, Denver, CO 80206.