The Johns Hopkins University Pediatric Pulmonary SCOR Program will correlate the findings in several laboratory research projects with the clinical features of cystic fibrosis and bronchiolitis. The Laboratory studies include mucociliary function, cell growth and metabolism, sweat components, ciliary inhibitory and sodium transport inhibitory "factors", serum proteins and polyamine metabolism. Controlled longitudinal epidemiologic studies will characterize the clinical pulmonary features of cystic fibrosis and bronchiolitis patients and their families; and will attempt to determine 1) Which Laboratory findings are specific for each disease and 2) How these laboratory measurements relate to the clinical features and 3) Which findings may be predictive of the course of the disease. Clinical and Laboratory core facilities will assist all of the SCOR projects.