Abstract
It is generally known that tubercles become atrophic or hyaline after the treatment with streptomycin or isoniazid, but its mechanism has not yet been clarified, and the present study was designated to explain this point. Guinea pigs were infected subcutaneously with M. tuberculosis Riku F. strain, and from the third week and the nineth week respectively, they were treated with either streptomycin or isoniazid for a period of 6 weeks. At the end of the treatment, they were sacrificed for pathological examination as well as.. for cultivation of tubercle bacilli in the organs. Autopsy findings in the third week 9f infection revealed that epithelioid cell tubercles were atrophic. On the other hand, in the nineth week of infection, tubercles were still proliferative in the liver, spleen and lung, but those in the lymphnodes were markedly productive, ani after 6 weeks' treatment tubercles in the liver, spleen and lung were atrophic while most of those in the lymphnodes were hyaline. From these findings, it will be considered that tubercles will become atrophic if streptomycin or isoniazid treatment is started during the period in which tubercles are still proliferative, but they will become hyaline if the treatment is started from the period they become productive. The same findings with the tubercles were observed in the epithelioid cell layer forming the capsule of caseous. is lesions. that is. in case chemotherapy is started when the fibrous production is markedly hyaline, but in cas?, the therapy is started during the period the epithelioid cell layer is cellular with little fibrous production, the epithelioid cell of the capsule will become atrophic and the capsule will become very thin.
