Abstract
1) LD50 of L-1 was 1,054 mg/kg and that of L-4 was 1,028 mg/kg, while the LD50 of INH was 650 mg/kg and PAS was 4,000mg/kg orally in the experimental animals.
2) L-1 and L-4 showed remarkable suppressive activity in vitro using solid media with 100r/ml. concentration. These data were parallel to 1r/ml. of INH and 50r/ml. of PAS. The inferiority of L-1 and L-4 to INH and PAS in vitro studies might have been due to the water insolubility of these compounds while INH and PAS were readily soluble in water.
3) In vivo experiments with L-1 showed a much-more superior antituberculous effect than was found with INH and PAS.
4) A method of grading the bacterial count in a homogenized tissue suspension of visceral organs (lungs, liver, spleen and kidneys) using the simple technique of the Gaffky scale was accurate and time saving technique in screening the results of the chemotherapeutic agents in tuberculosis.
5) Among the newly synthesized compounds L-4 showed the most remarkable suppressive effect on murine leprosy. The suppressive results were similar to those of INH.
6) The method of measuring the size and the weight of leproma at the inoculated site was simple and is an adequate screening test for chemotherapeutic effect in murine leprosy.
7) In the trials with human leprosy 16 cases of various types, using L-4, the effectiveness in clinical as well as in bacteriological improvement was remarkable.
a) After L-4 treatment decrease in bactriologica1 indices and remarkable clinical improvement after a relative1y short period of treatment were observed.
b) L-4, up to the maximum daily dose of 500 mg, can be safely administered orally to the patients without any significant side reactions.
c) L-4 could be used with remarkable clinical improvement for the patients in lepra reactions.