1,459 research outputs found

    Simultaneous alterations in ovaries and bone as a result of Polycystic Ovary Syndrome

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    Polycystic ovary syndrome (PCOS) is one of the most widely recognized endocrine disorders affecting reproductive-age women. The etiopathogenesis and mechanisms of this syndrome remain unclear. Diagnosis requires two of the following: polycystic ovaries, oligo- or anovulation, and hyperandrogenism. Most women with PCOS display conditions such as metabolic abnormalities, diabetes, obesity, cardiovascular disease, and/or bone dysfunction. Considering the ethical limitations of human studies, animal and cell culture models that reflect some features of PCOS are important for investigation of this syndrome. The aim of the present work was to study some of the endocrine relationships between ovaries and bone tissue in a polycystic ovary syndrome animal model. The study was performed using an estradiol valerate PCOS-induced rat model (n = 30) and bone mesenchymal stem cell cultured from bone marrow of those animals. It was hypothesized that changes of the endocrine relationship between ovaries and bones could be observed in from in vivo animal model and in vitro cell culture assays. The ovarian morphological and endocrine changes seem to be correlated with endocrine, biophysical, and biomechanical changes in bone properties. Mesenchymal stem cells obtained from PCOS-induced rats, cultured for up to 21 days and differentiated into osteoblasts, presented lower viability and reduced mineralization of the extracellular matrix. Taken together, these results indicate important endocrine and structural effects of PCOS in ovaries and bones, contributing to part of the understanding of the pathophysiological mechanisms of PCOS

    Collagen V-induced nasal tolerance downregulates pulmonary collagen mRNA gene and TGF-beta expression in experimental systemic sclerosis

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study was to evaluate collagen deposition, mRNA collagen synthesis and TGF-beta expression in the lung tissue in an experimental model of scleroderma after collagen V-induced nasal tolerance.</p> <p>Methods</p> <p>Female New Zealand rabbits (N = 12) were immunized with 1 mg/ml of collagen V in Freund's adjuvant (IM). After 150 days, six immunized animals were tolerated by nasal administration of collagen V (25 μg/day) (IM-TOL) daily for 60 days. The collagen content was determined by morphometry, and mRNA expressions of types I, III and V collagen were determined by Real-time PCR. The TGF-beta expression was evaluated by immunostaining and quantified by point counting methods. To statistic analysis ANOVA with Bonferroni test were employed for multiple comparison when appropriate and the level of significance was determined to be <it>p </it>< 0.05.</p> <p>Results</p> <p>IM-TOL, when compared to IM, showed significant reduction in total collagen content around the vessels (0.371 ± 0.118 vs. 0.874 ± 0.282, <it>p </it>< 0.001), bronchioles (0.294 ± 0.139 vs. 0.646 ± 0.172, <it>p </it>< 0.001) and in the septal interstitium (0.027 ± 0.014 vs. 0.067 ± 0.039, <it>p </it>= 0.026). The lung tissue of IM-TOL, when compared to IM, showed decreased immunostaining of types I, III and V collagen, reduced mRNA expression of types I (0.10 ± 0.07 vs. 1.0 ± 0.528, p = 0.002) and V (1.12 ± 0.42 vs. 4.74 ± 2.25, p = 0.009) collagen, in addition to decreased TGF-beta expression (p < 0.0001).</p> <p>Conclusions</p> <p>Collagen V-induced nasal tolerance in the experimental model of SSc regulated the pulmonary remodeling process, inhibiting collagen deposition and collagen I and V mRNA synthesis. Additionally, it decreased TGF-beta expression, suggesting a promising therapeutic option for scleroderma treatment.</p

    The motivational drive to natural rewards is modulated by prenatal glucocorticoid exposure

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    Exposure to elevated levels of glucocorticoids (GCs) during neurodevelopment has been identified as a triggering factor for the development of reward-associated disorders in adulthood. Disturbances in the neural networks responsible for the complex processes that assign value to rewards and associated stimuli are critical for disorders such as depression, obsessive–compulsive disorders, obesity and addiction. Essential in the understanding on how cues influence behavior is the Pavlovian–instrumental transfer (PIT), a phenomenon that refers to the capacity of a Pavlovian stimulus that predicts a reward to elicit instrumental responses for that same reward. Here, we demonstrate that in utero exposure to GCs (iuGC) impairs both general and selective versions of the PIT paradigm, suggestive of deficits in motivational drive. The iuGC animals presented impaired neuronal activation pattern upon PIT performance in cortical and limbic regions, as well as morphometric changes and reduced levels of dopamine in prefrontal and orbitofrontal cortices, key regions involved in the integration of Pavlovian and instrumental stimuli. Normalization of dopamine levels rescued this behavior, a process that relied on D2/D3, but not D1, dopamine receptor activation. In summary, iuGC exposure programs the mesocorticolimbic dopaminergic circuitry, leading to a reduction in the attribution of the incentive salience to cues, in a dopamine-D2/D3-dependent manner. Ultimately, these results are important to understand how GCs bias incentive processes, a fact that is particularly relevant for disorders where differential attribution of incentive salience is critical.We thank Pedro Morgado for discussions and help in the technical aspects of PIT procedure. This project was supported by a grant of Institute for the Study of Affective Neuroscience (ISAN) and by Janssen Neuroscience Prize. CS-C, SB, MMC and AJR are recipients of Fundacao para a Ciencia e Tecnologia (FCT) fellowships (CS-C: SFRH/BD/51992/2012; SB: SFRH/BD/89936/2012; MMC: SRFH/BD/51061/2010; AJR: SFRH/BPD/33611/2009)

    Designing an ontology-based Zika virus news authoring environment for the semantic web

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    This paper describes the experience of researching and teaching the conceptual and practical basis for the specification, modelling and design of an ontology-based news authoring environment for the Semantic Web, that takes into account the construction and use of an ontology of the Zika disease. Some CMSs are being adapted in order to receive semantic features, such as automatic generations of keywords, semantic annotation and tagging, content reviewing etc. We present here the infrastructure designed to foster research on semantic CMSs as well as semantic web technologies that can be integrated into an ontology-based news authoring environment

    Drought generates large, long-term changes in tree and liana regeneration in a monodominant Amazon forest

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    The long-term dynamics of regeneration in tropical forests dominated by single tree species remains largely undocumented, yet is key to understanding the mechanisms by which one species can gain dominance and resist environmental change. We report here on the long-term regeneration dynamics in a monodominant stand of Brosimum rubescens Taub. (Moraceae) at the southern border of the Amazon forest. Here the climate has warmed and dried since the mid-1990′s. Twenty-one years of tree and liana regeneration were evaluated in four censuses in 30 plots by assessing species abundance, dominance, and diversity in all regeneration classes up to 5 cm diameter. The density of B. rubescens seedlings declined markedly, from 85% in 1997 to 29% in 2018 after the most intense El Niño-driven drought. While the fraction contributed by other tree species changed little, the relative density of liana seedlings increased from just 1 to 54% and three-quarters of liana species underwent a ten-fold or greater increase in abundance. The regeneration community experienced a high rate of species turnover, with changes in the overall richness and species diversity determined principally by lianas, not trees. Long-term maintenance of monodominance in this tropical forest is threatened by a sharp decline in the regeneration of the monodominant species and the increase in liana density, suggesting that monodominance will prove to be a transitory condition. The close association of these rapid changes with drying indicates that monodominant B. rubescens forests are impacted by drought-driven changes in regeneration, and therefore are particularly sensitive to climatic change
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