Figure 1.

Fibrotic lung injury models. C57Bl/6NCr mice were exposed to 0 Gy (control), 5 Gy, 17.5 Gy, 5×6 Gy, or 5×5 Gy of thoracic irradiation (IR). A) Kaplan–Meier plot of survival of irradiated mice through 30 weeks. The reported P value is from log rank comparing survival curves. All statistical tests were two-sided. The number at risk for each time point is listed in the table directly below the survival curve. B) Image of a mouse treated with 17.5 Gy at 30 weeks. The coat in the treated region thins and lightens. C) Masson trichrome staining of lung tissue collected at 30 weeks after IR (control, 5 Gy, 17.5 Gy, 5×5 Gy) or 20 weeks after IR (5×6 Gy). Lungs treated to 17.5 Gy or with the fractionated doses develop foci of fibrosis. Collagen: blue; nuclei: purple; cytoplasm/epithelia: pink. Scale bar = 40 μm.