Dr. Kleeberger and colleagues at Johns Hopkins University compared ozone-induced inflammation, epithelial cell injury, and epithelial cell proliferation (a marker of cell injury) in three types of mice: mice with a normal content of mast cells, mutant mice without mast cells, and mutant mice whose mast cells were repleted by a bone marrow transplant from normal mice. Each group of mice was exposed to clean air or to ozone for varying lengths of time.
