OBJECTIVE: To investigate the relationship between exogenous @entity172 and @entity0 risk. METHODS: Female @entity35 were randomly divided into three groups, namely @entity4742 ( @entity4743 ), @entity8098 compositae (CoNET) and control group. The histological structure and ultrastructural changes of mammae were observed. The levels of sexual hormones in serum were determined and the AgNOR counts, DNA contents and @entity134 receptor contents in mammary epithelium were also detected. RESULTS: In @entity4743 group, the level of @entity1420 (10.38 ng/ml) was obviously lower than that in the control group (13.37 ng/ml); the incidence of @entity1373 of mammary gland (73.33%) was significantly higher than that in the control group (7.69%); and the degree of @entity1373 was obviously more serious than that in the control group. Moreover, there were 13.33% of @entity35 with @entity1373 in @entity4743 group. The DNA contents, AgNOR counts and @entity172 receptor (ER) positive rate were markedly higher in @entity4743 group (95.60, 2.43 and 71.71% respectively) than in the control group (83.07, 1.88 and 40% respectively). However, in CoNET group, there were no obvious influences on ER, AgNOR and DNA in mammary epithelium. CONCLUSIONS: Exogenous @entity172 ( @entity4743 ) could affect the levels of sexual hormones in serum, accelerate the DNA duplication, increase the AgNOR counts and ER contents, and induce @entity1373 and ultrastructural changes of mammary gland, hence becoming a latent risk factor of @entity0 . However, the results failed to suggest that the contraceptive, CoNET, could increase the risk of @entity0 .

Experimental study on relationship between exogenous XXXX and @entity0 risk.

@entity172 :: ('MESH:D004967', 'Chemical') :: ['estrogen'] @entity8098 :: ('MESH:D009640', 'Chemical') :: ['norethindrone'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast cancer'] @entity1420 :: ('MESH:D011374', 'Chemical') :: ['progesterone'] @entity1373 :: ('MESH:D006965', 'Disease') :: ['hyperplasia', 'atypical hyperplasia'] @entity4743 :: ('CHEBI:37628', 'Chemical') :: ['DES'] @entity134 :: ('CHEBI:35341', 'Chemical') :: ['steroid'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity4742 :: ('MESH:D004054', 'Chemical') :: ['diethylstilbestrol']
@entity172 :: (MESH:D004967,Chemical) :: ['estrogen']
