Effects of inhaled 144CeO2 on influenza virus infection in mice

The effects of chronic beta-radiation from inhaled 144CeO2 that resulted in beta-radiation doses of 16,000 to 19,000 rads to the lung during 8- to 20-wk intervals had little or no effect on the influenza virus concentration or hemagglutinin titers in the lungs of virus inoculated mice when compared with virus inoculated control mice. There was, however, a slight effect in suppressing hemagglutination inhibiting antibody formation. Lung weights, lung lesions and mortality of mice inoculated with influenza virus at 8, 12 and 20 wk after inhaling 144CeO2 were reported. Increased mortality occurred at 8 wk, increases in all three parameters at 12 wk and increases in lung weights and lung lesions were observed at 20 wk. Mice that inhaled 144CeO2 and were inoculated with virus had significant histo-pathological changes. These were most marked in the mice infected with virus at 20 wk postexposure in which squamous cell differentiation was a prominent finding progressing in one case to a superficial resemblance to epidermoid carcinoma.