[Phagocytosis and intracellular proliferation of Nocardia asteroides (strain Weipheld) in cell structures in vitro. 1. Alveolar macrophages of guinea-pigs (author's transl)].

Phagocytosis and intracellular proliferation of Nocardia asteroides (Weipheld) were studied in alveolar macrophages from normal guinea-pigs that had been immunized in two stages and guinea-pigs that had undergone long-term cortisone treatment (28 mg/kg/day over 30 days). The highest phagocytosis values were found in the guinea-pigs that had been immunized in two stages (3.85-6.82%). In the case of normal macrophages, values of 2.90-4.95% were observed. The lowest values (2.10-3.6%) were found for macrophages from those guinea-pigs that had been treated with hydrocortisone. Differences between the groups were statistically significant. Following phagocytosis, the phagocytosis index was seen rising in all three groups, reaching its highest values for alveolar macrophages from the cortisone-treated guinea-pigs (after 8 hours - 1.15). The cytotoxic effects of Nocardia upon the cells in the lung washing liquid from normal guinea-pigs immunized in two steps and guinea-pigs treated with high cortisone doses over an extended period were exhibiting identical trends. After 8 hours' exposure, 22.6% dead and decayed cells were found, against 5.9% in normal controls. Leucocytes proved to be most susceptible to the cytotoxic effect of Nocardia; alveolar macrophages were less and small lymphocytes least susceptible.