A bioassay of @entity4765 , a prophylactic antimalarial, for possible carcinogenicity was conducted by administering the test chemical in feed to Fischer 344 @entity35 and B6C3F1 @entity19 . Groups of 35 @entity35 and 35 @entity19 of each sex were administered @entity4765 5 days per week at one of two doses, either 200 or 400 ppm for the @entity35 and either 500 or 1,000 ppm for the @entity19 . The animals were administered the chemical for 78 weeks, then observed for 26 or 27 additional weeks. Matched controls consisted of 15 untreated @entity35 and 15 untreated @entity19 of each sex; pooled controls consisted of the matched controls combined with 30 untreated @entity35 and 30 untreated @entity19 from similar bioassays of two other test compounds. All surviving @entity35 and @entity19 were killed at 102-105 weeks. Mean body weights of the @entity35 and @entity19 fed diets containing @entity4765 were slightly lower than those of the matched controls. Survival of the @entity35 was not affected adversely by the chemical. In @entity19 , survival rates of both dosed and matched-control males were low, with nearly two-thirds of the dosed and one-half of the control @entity19 dying by week 52. Some of the @entity204 were associated with @entity1729 and may not have been related to administration of the chemical. Numbers of animals at risk in the dosed and control groups of female @entity19 were adequate, however, for the development of late-appearing @entity5 . In @entity35 of each sex, no @entity1313 were found at a statistically significant incidence in the groups fed the @entity4765 as compared with control groups. An increased frequency of bone-marrow @entity194 occurred in both male and female dosed groups. In male @entity19 , the markedly decreased life spans may have prevented the observation of late-appearing @entity5 , since only two @entity5 were observed, one in a high-dose @entity19 and one in a low-dose @entity19 . In female @entity19 , no @entity1313 were found at a statistically significant incidence in the groups fed the @entity4765 as compared with control groups. It is concluded that under the conditions of this bioassay, @entity4765 was not carcinogenic for male or female Fischer 344 @entity35 or for female B6C3F1 @entity19 . The carcinogenic potential of @entity4765 for male B6C3F1 @entity19 cannot be assessed by this bioassay, because of the markedly reduced life span.

Bioassay of XXXX for possible carcinogenicity.

@entity1313 :: ('MESH:D001932', 'Disease') :: ['neoplastic lesions'] @entity19 :: ('10090', 'Species') :: ['mice', 'mouse'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumors'] @entity194 :: ('MESH:D001284', 'Disease') :: ['atrophy'] @entity1729 :: ('MESH:D012141', 'Disease') :: ['respiratory infections'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity4765 :: ('MESH:D011739', 'Chemical') :: ['pyrimethamine'] @entity204 :: ('MESH:D003643', 'Disease') :: ['deaths']
@entity4765 :: (MESH:D011739,Chemical) :: ['pyrimethamine']
