02165nas a2200313   4500000000100000008004100001260001300042653001200055653002100067653001200088653002700100653001100127653001200138653000900150653000900159653002400168653002500192653000900217653002100226653002500247653001500272100001900287700001100306245010200317300001000419490000700429520140100436022001401837       1976                            d  c1976 Nov10aAnimals10aAnimals, Newborn10aDapsone10aDisease Models, Animal10aFemale10aleprosy10aMale10aMice10aMice, Inbred BALB C10aMycobacterium leprae10aRats10aRats, Inbred Lew10aRats, Inbred Strains10aThymectomy1 aFieldsteel A H1 aLevy L00aDapsone chemotherapy of Mycobacterium leprae infection of the neonatally thymectomized Lewis rat.  a854-90 v253 a<p>In order to learn whether the neonatally thymectomized Lewis rat (NTLR) infected with Mycobacterium leprae could serve as a model for chemotherapeutic studies in a situation resembling that found in human lepromatous leprosy, NTLR inoculated with M. leprae either locally or intravenously 9 to 16 months earlier were treated for from 1.5 to 8.5 months with dapsone (4,4'-diaminodiphenylsulfone, DDS) incorporated in the rat chow in the concentration providing the minimal inhibitory concentration of the drug for M. leprae and in the 100-fold larger concentration. NTLR were killed at intervals; the M. leprae were counted and passed to mice. Treatment with the smaller dosage of dapsone neither killed M. leprae nor reduced the number of organisms in the bacterial populations, whereas treatment with the larger dosage both killed M. leprae and reduced their numbers. The rate at which the organisms were killed (i.e., rendered noninfective for mice) was much the same as that in patients treated with dapsone in comparable dosage. The dead organisms were removed from the rat tissues at a faster rate than encountered in patients. The NTLR may indeed be suitable for chemotherapeutic studies relevant to man. In addition, the more rapid disappearance of dead M. leprae from the rat tissues may facilitate the study of treatment regimens designed to eradicate persisting viable organisms.</p>  a0002-9637