Developmental exposure to estrogenic chemicals induces morphological, functional, and behavioral anomalies associated with reproduction. Humans are exposed to bisphenol-A (BPA), an estrogenic compound that leaches from dental materials and plastic food and beverage containers. The aim of the present study was to determine the effects of perinatal exposure to low, environmentally relevant doses of BPA [25 and 250 ng BPA/kg body weight (bw).d] on the peripubertal development of the mammary gland. BPA exposure enhanced the mammary glands' sensitivity to estradiol in ovariectomized CD-1 mice. In their intact 30-d-old littermates, the area and numbers of terminal end buds relative to the gland ductal area increased whereas their apoptotic activity decreased. There was a positive correlation between ductal length and the age at first proestrus; that was reduced as the BPA dose increased, suggesting that BPA exposure slows down ductal invasion of the stroma. There was also a significant increase of progesterone receptor-positive ductal epithelial cells that were localized in clusters, suggesting future branching points. Indeed, lateral branching was significantly enhanced at 4 months of age in mice exposed to 25 ng BPA /kg bw.d. In conclusion, perinatal exposure to environmentally relevant BPA doses results in persistent alterations in mammary gland morphogenesis. Of special concern is the increased terminal end bud density at puberty as well as the increased number of terminal ends reported previously in adult animals, as these two structures are the sites at which cancer arises in humans and rodents.

Exposure to estrogens throughout a woman's life, including the period of intrauterine development, is a risk factor for the development of breast cancer. The increased incidence of breast cancer noted during the last 50 years may have been caused, in part, by exposure of women to estrogen-mimicking chemicals that are released into the environment. Here, we investigated the effects of fetal exposure to one such chemical, bisphenol A (BPA), on development of the mammary gland. CD-1 mice were exposed in utero to low, presumably environmentally relevant doses of BPA (25 and 250 microg/kg body weight), and their mammary glands were assessed at 10 days, 1 mo, and 6 mo of age. Mammary glands of BPA-exposed mice showed differences in the rate of ductal migration into the stroma at 1 mo of age and a significant increase in the percentage of ducts, terminal ducts, terminal end buds, and alveolar buds at 6 mo of age. The percentage of cells that incorporated BrdU was significantly decreased within the epithelium at 10 days of age and increased within the stroma at 6 mo of age. These changes in histoarchitecture, coupled with an increased presence of secretory product within alveoli, resemble those of early pregnancy, and they suggest a disruption of the hypothalamic-pituitary-ovarian axis and/or misexpression of developmental genes. The altered relationship in DNA synthesis between the epithelium and stroma and the increase in terminal ducts and terminal end buds are striking, because these changes are associated with carcinogenesis in both rodents and humans.

To test the hypothesis that tolerating some subretinal fluid (SRF) in patients with neovascular agerelated macular degeneration (nAMD) treated with ranibizumab using a treat-and-extend (T&E) regimen can achieve similar visual acuity (VA) outcomes as treatment aimed at resolving all SRF.Design: Multicenter, randomized, 24-month, phase 4, single-masked, noninferiority clinical trial.Participants: Participants with treatment-naïve active subfoveal choroidal neovascularization (CNV). Methods: Participants were randomized to receive ranibizumab 0.5 mg monthly until either complete resolution of SRF and intraretinal fluid (IRF; intensive arm: SRF intolerant) or resolution of all IRF only (relaxed arm: SRF tolerant except for SRF >200 mm at the foveal center) before extending treatment intervals. A 5-letter noninferiority margin was applied to the primary outcome.Main Outcome Measures: Mean change in best-corrected VA (BCVA), and central subfield thickness and number of injections from baseline to month 24.Results: Of the 349 participants randomized (intensive arm, n ¼ 174; relaxed arm, n ¼ 175), 279 (79.9%) completed the month 24. The mean change in BCVA from baseline to month 24 was 3.0 letters (standard deviation, 16.3 letters) in the intensive group and 2.6 letters (standard deviation, 16.3 letters) in the relaxed group, demonstrating noninferiority of the relaxed compared with the intensive treatment (P ¼ 0.99). Similar proportions of both groups achieved 20/40 or better VA (53.5% and 56.6%, respectively; P ¼ 0.92) and 20/200 or worse VA (8.7% and 8.1%, respectively; P ¼ 0.52). Participants in the relaxed group received fewer ranibizumab injections over 24 months (mean, 15.8 [standard deviation, 5.9]) than those in the intensive group (mean, 17 [standard deviation, 6.5]; P ¼ 0.001). Significantly more participants in the intensive group never extended beyond 4-week treatment intervals (13.5%) than in the relaxed group (2.8%; P ¼ 0.003), and significantly more participants in the relaxed group extended to and maintained 12-week treatment intervals (29.6%) than the intensive group (15.0%; P ¼ 0.005).Conclusions: Patients treated with a ranibizumab T&E protocol who tolerated some SRF achieved VA that is comparable, with fewer injections, with that achieved when treatment aimed to resolve all SRF completely.

Developmental exposure to estrogenic chemicals induces morphological, functional, and behavioral anomalies associated with reproduction. Humans are routinely exposed to bisphenol-A (BPA), an estrogenic compound that leaches from dental materials and plastic food and beverage containers. The aim of the present study was to determine the effects of in utero exposure to low, environmentally relevant doses of BPA on the development of female reproductive tissues in CD-1 mice. In previous publications, we have shown that this treatment alters the morphology of the mammary gland and affects estrous cyclicity. Here we report that in utero exposure to 25 and 250 ng BPA/ kg of body weight per day via osmotic pumps implanted into pregnant dams at Gestational Day 9 induces alterations in the genital tract of female offspring that are revealed during adulthood. They include decreased wet weight of the vagina, decreased volume of the endometrial lamina propria, increased incorporation of bromodeoxyuridine into the DNA of endometrial gland epithelial cells, and increased expression of estrogen receptor-alpha (ERalpha) and progesterone receptor in the luminal epithelium of the endometrium and subepithelial stroma. Because ERalpha is known to be expressed in these estrogen-target organs at the time of BPA exposure, it is plausible that BPA may directly affect the expression of ER-controlled genes involved in the morphogenesis of these organs. In addition, BPA-induced alterations that specifically affect hypothalamic-pituitary-gonadal axis function may further contribute to the anomalies observed at 3 mo of age, long after the cessation of BPA exposure.

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Recent findings in the field of environmental endocrine disruption have revealed that developmental exposure to estrogenic chemicals induces morphological, functional, and behavioral anomalies associated with reproduction. The aim of the present study was to determine the effects of in utero exposure to low doses of the estrogenic chemical bisphenol A (BPA) on the development of the female reproductive tissues and mammary glands in CD-1 mice. Humans are exposed to BPA, which leaches from dental materials and plastic food and beverage containers. Here we report that prenatal exposure to BPA induces alterations in tissue organization within the ovaries and mammary glands and disrupts estrous cyclicity in adulthood. Because estrogen receptors are expressed developmentally in these estrogen-target organs, we propose that BPA may directly affect the expression of genes involved in their morphogenesis. In addition, alterations in the sexual differentiation of the brain, and thus the hypothalamic-pituitary-gonadal axis, may further contribute to the observed phenotype. The emerging field of endocrine disruptors promises to provide new insights into the mechanisms underlying the development of hormone-target organs and demonstrates that the environment plays important roles in the making of phenotypes.

The prevalence of synthetic chemicals in our environment that are capable of mimicking the female hormone estrogen is a growing concern. One such chemical, bisphenol A (BPA), has been shown to leach from a variety of resin-based and plastic products, including dental sealants and food and beverage containers, in concentrations that are sufficient to induce cell proliferation in vitro. The response to BPA in vivo has been varied; thus the aims of this study were to investigate a) whether BPA has an estrogenic effect in CD-1 mice, a strain that is useful for developmental studies; and b) whether the uterotrophic assay is a valid means of determining the estrogenicity of BPA by comparing it with other end points measured in the uterus. Immature female CD-1 mice were exposed to BPA in concentrations ranging from 0.1 to 100 mg/kg body weight for 3 days. Results showed that BPA induced a significant increase in the height of luminal epithelial cells within the uterus at concentrations of 5, 75, and 100 mg/kg and that BPA induced lactoferrin at concentrations of 75 and 100 mg/kg. A uterotrophic response (increase in uterine wet weight) was induced by 100 mg/kg BPA only. Further, the proportion of mice showing vaginal opening was greater after exposure to 0.1 and 100 mg/kg BPA, relative to the control animals and those receiving intermediate doses of BPA. These results demonstrate that BPA induces changes in the mouse uterus that differ depending on the exposure dose and the end point measured, and reveal that certain tissue effects show a nonmonotonic relationship with dose. These data also demonstrate that BPA induces estrogenic changes in the uterus of the CD-1 mouse, and highlight the need to reevaluate the validity of the mouse uterotrophic assay as an end point for determining the estrogenicity of suspected environmental estrogens.

BackgroundWith increasing experience using anti-VEGF therapy for the treatment of neovascular age-related macular degeneration (nAMD), ophthalmologists have shifted away from a “one size fits all” to an “individualised” approach based on disease activity with the aim of achieving a fluid-free retina. The FLUID study investigates the non-inferiority of a Treat and Extend (T&E) protocol of 0.5 mg ranibizumab, which allows treatment extension in the presence of incomplete resolution of sub-retinal fluid (SRF) ≤200 μm at the foveal centre relative to a T&E protocol that requires complete resolution of all retinal fluid (i.e., both SRF and intra-retinal fluid [IRF]) in patients with nAMD.Methods/DesignThis 24 month, randomised, phase IV trial has completed recruitment of treatment-naïve patients randomised 1:1 to ranibizumab “intensive” treatment (complete resolution of IRF and SRF) or ranibizumab “relaxed” treatment (resolution of IRF or >200 μm SRF only at foveal centre). Patients in both arms follow a T&E regimen where extension decisions are based upon assessment of lesion activity: loss of ≥5 letters of visual acuity, new haemorrhage, presence of IRF and SRF on an optical coherence tomography (OCT) scan. The determination of SRF is conducted at a reading centre while the assessment of IRF is physician-determined. The primary endpoint is the mean change in best-corrected visual acuity (BCVA) from baseline to 24 months. Secondary endpoints include the mean change in central retinal thickness (CRT) from baseline to 12 and 24 months, the number of ranibizumab injections administered at 12 and 24 months, and the pharmacogenomic assessment of AMD Gene Consortium-identified single-nucleotide polymorphisms (SNPs) and their association with treatment response. Three hundred and forty seven (347) patients have been recruited by 16 Australian sites within approximately 16 months. A protocol to adjudicate on SRF has been established by the central reading centre and is demonstrating good concordance with investigator assessment.DiscussionThis study will provide important insights into retreatment criteria for managing nAMD using a T&E regimen. The current paper describes the clinical rationale for using a less intensive treatment approach using ranibizumab and details of the treatment protocol.Trial registrationTrial registration number: NCT01972789. Date of registration: 24th October 2013.