The Pathogenicity of Bagasse,II. Effect on Rabbits of Prolonged Exposure to Bagasse. *

Conclusions

These experimental and comparative studies permit the conclusion that the inorganic part of the inhaled bagasse dust produces a long-standing tissue reaction which is primarily a foreign body response. It is unlike silicosis and amenable to healing by resolution. Superimposed on these lesions there occurs in those animals which are more susceptible to the causative microorganisms acute bronchiolitic and pneumonic changes which, if sufficiently extensive, may cause death of the animal. A similar combination of etiologic factors seems to be the most plausible explanation of the complex picture of human bagasse disease.

Summary. Bagasse irrespective of the route ol administration, produces a complex and frequently progressive inflammatory reaction of the exposed animal. By employing native, in contrast to autoclaved bagasse and its extracted resins and minerals, it could be demonstrated that the fiber itself calls forth a long-standing foreign body reaction which is amenable to healing. The progressive inflammatory reaction and death of the animal, however, are due to microorganisms attached to the bagasse. In the instance of the rabbit, aspergilli are the pathogenic agents. The points of similarity of the experimental lesions to those observed in humans are discussed. None of the lesions resembled silicosis.