@entity18519 is an ingredient in dandruff shampoos used in concentrations of 1% in products sold over-the-counter and 2.5% in products which are available by prescription only. Prescription shampoos have been shown in clinical studies to be of therapeutic value against dandruff. An antimitotic mechanism of action is suggested by data showing that @entity18519 decreases the rate of incorporation of radioactively labeled @entity1014 into the DNA of dermal epithelial cells. Approximately 200 kg of @entity18519 is estimated to be used annually for this purpose. A bioassay of @entity18519 for possible carcinogenicity was conducted by administering this substance by gavage to F344 @entity35 and B6C3F1 @entity19 . Groups of 50 @entity35 and 50 @entity19 of each sex were administered @entity18519 suspended in 0.5% aqueous carboxymethylcellulose 7 days per week for 103 weeks at either 3 or 5 mg/kg/day for @entity35 and 20 or 100 mg/kg/day for @entity19 . As vehicle controls, groups of 50 @entity35 and 50 @entity19 of each sex were administered only the 0.5% aqueous carboxymethylcellulose. Similar groups of untreated controls also were used. All surviving @entity35 and @entity19 were killed and necropsied at week 104 or 105. The significant effects that could be related to administration of @entity18519 at the doses used were decreased body weight and increased @entity5 formation in female @entity19 and in @entity35 of each sex. Dosed @entity35 and female @entity19 had an increased incidence of @entity157 and @entity652 . Dosed female @entity19 also had an increased incidence of @entity133 and @entity652 . Under the conditions of this bioassay, @entity18519 was carcinogenic for F344 @entity35 and female B6C3F1 @entity19 , including @entity157 in male and female @entity35 and female @entity19 and @entity133 and @entity652 in female @entity19 . @entity18519 was not carcinogenic for male @entity19 ; but they have been able to tolerate higher doses. Levels of Evidence of Carcinogenicity: Male @entity35 : Positive Female @entity35 : Positive Male @entity19 : Negative Female @entity19 : Positive

Bioassay of XXXX (Gavage) for Possible Carcinogenicity (CAS No. 7446-34-6).

@entity19 :: ('10090', 'Species') :: ['mice', 'Mice'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity133 :: ('MESH:D002282', 'Disease') :: ['alveolar/bronchiolar carcinomas'] @entity1014 :: ('MESH:D013936', 'Chemical') :: ['thymidine'] @entity18519 :: ('MESH:C025698', 'Chemical') :: ['selenium sulfide', 'Selenium sulfide'] @entity35 :: ('10116', 'Species') :: ['Rats', 'rats'] @entity157 :: ('MESH:D006528', 'Disease') :: ['hepatocellular carcinomas'] @entity652 :: ('MESH:D000236', 'Disease') :: ['adenomas']
@entity18519 :: (MESH:C025698,Chemical) :: ['Selenium Sulfide']
