Abstract Pestivirus can contaminate cell cultures and sera and cause serious problems that evolve the integrity of studies, confidence in diagnostic results, and safety of human and animal vaccines. Contaminations by Pestivirus and other viruses may occur at any time and regular assays of monitoring in cell cultures and your supplies are necessary. This study aimed to analyze the phylogeny of Pestivirus detected from cell cultures, calf serum, and standard strains of three laboratories in Brazil that carry out frequent tests for the monitoring of cellular contaminations. These samples were submitted to phylogenetic analysis to understand the genetic relationship between contaminants occurring in these facilities. As result, the Pestivirus found in samples were Bovine viral diarrhea virus (BVDV-1 and BVDV-2), Hobi-like viruses (often named BVDV-3), and Classical swine fever virus (CSFV), and the phylogenetic analysis help us to infer at three possible routes of contamination in this work.

Increased levels of androgens in postmenopausal women are considered to be a risk factor for breast cancer. Testosterone, alone or in combination with estrogen, induces epithelial dysplasia and mammary tumors in Noble rats. Since this model of hormone-induced neoplasia has not been reported in other rat strains, we studied the effect of testosterone on the mammary gland morphology of female Wistar rats. Sixty adult, non-castrated, female Wistar rats were implanted in the dorsum midline with a silicone tube containing 50 mg testosterone (testosterone propionate in 30 animals and non-esterified testosterone in the remaining 30 animals) and 20 additional animals were implanted with empty tubes and used as control. Five animals per group were killed 30, 60, 90, 120, 150, and 180 days after implantation, and the mammary glands were dissected, fixed and embedded in paraffin. Histological sections were then stained with hematoxylin and eosin and picrosyrius red for collagen visualization. Morphological and morphometric analysis demonstrated ductal proliferation and acinotubular differentiation with secretory activity in all treated animals, peaking at 90 days of androgen exposure. After 90 days the proliferation of acinar epithelial cells was evident, but there was a progressive reduction of secretory differentiation and an increase in intralobular collagen fibers. There was no morphological evidence of dysplastic changes or other pre-neoplastic lesions. Testosterone treatment applied to adult, non-castrated female Wistar rats induced a mammary gland hyperplasia resembling the lactating differentiation, with progressive reduction in secretory differentiation.