Abstract
1) Clinical conditions of the patients, isoniazzd resistance, and virulence to guinea pigs of the bacilli were observed on 5 patients with chronic pulmonary tuberculosis, far advanced in extent, who had been given 200 to 350mg of INH daily for a year. The clinical conditions of all cases were not changed, the isoniazid resistance increased on 4 cases except one. The attenuated virulence with increase of isoniazid resistance was noted on 2 cases. Any definite relation was not observed on the other 3 cases.
2) The clinical conditions were observed on 106 cases with isoniazid resistant bacilli for up to 6 years.
The isoniazid resistance did not always make the prognosis of the pulmonary tuberculous patients worse; clinical symptoms were unchanged or became better at least.
It was believed that the extent of pulmonary lesion and the grade of the SM-resistance were large factors to give influence on their clinical course.
