Fig. 10

Histologic sections of bronchioles from calves that received aerosolized bacterial lysate 24 h prior to euthanasia. At lower doses of bacterial lysate (a, calf 1, 10⁸ CFU-equivalents; and b, calf 2, 10⁹ CFU equivalents), the bronchioles have no or few neutrophils within their lumens. At higher doses of bacterial lysate (c, calf 3, 10¹⁰ CFU-equivalents; and d, calf 4, 10¹¹ CFU-equivalents) there are neutrophils within bronchioles. Bar = 40 μm