53 research outputs found

    Linguistic expert creation in online health practices

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    In this chapter, we explore how the construction of an expert identity varies across online e-health settings with different socio-technological features. Our methodology is qualitative in nature and draws on insights from discourse analysis, in particular positioning theory. Results show that four aspects of creating expertise are vital: the embeddedness of the posi-tioning strategies in the online health context, the interplay between these strategies within each setting, the interactivity of the medium, and the fact that not only professionals, but also clients and laypeople construct their expertise. The results reveal that previously found strategies to create expertise (e.g., using jargon or showing empathy) could be confirmed in our corpus, and that the interplay of several strategies is in fact needed to create credible and trustworthy expert identities for all participants involved. This interplay varies accord-ing to the practice

    Culturally valuable minority crops provide a succession of floral resources for flower visitors in traditional orchard gardens

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    Agricultural intensification typically has detrimental effects on pollinator communities, but diverse cropping systems that contain sequentially-flowering crops have the potential to benefit pollinators through the provision of additional floral resources. In this study we investigate the importance of cultivated flora for flower visitors in ten agricultural gardens in South Sinai, Egypt. Insect-flower interactions in gardens and unmanaged plots were surveyed across a four-month period in two environmentally distinct years (pre-flood and post-flood). Despite containing an equal abundance and diversity of wild plants as unmanaged habitat, gardens supported a higher abundance and diversity of flower visitors due to the additional presence of cultivated flora. Visitation networks exhibited dramatic intra-annual changes in composition, with cultivated plants becoming increasingly important in later months. Trends were highly conserved across 2 years despite highly contrasting rainfall. Several key crop species were strongly involved in shaping the structure of the networks, the majority of which were herbs with strong cultural significance (fennel, rosemary, mint) and grown incidentally alongside the primary orchard crops. Minority crops are frequently overlooked in agricultural systems due to their low economic value, but we show that they can have a dramatic influence upon the structure of visitation networks, increasing both pollinator abundance and diversity, and emphasising the link between cultural practices and biodiversity conservation

    Latent transforming growth factor binding protein 4 (LTBP4) is downregulated in mouse and human DCIS and mammary carcinomas

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    Transforming growth factor beta (TGF-) is able to inhibit the proliferation of epithelial cells and is involved in the carcinogenesis of mammary tumors. Three latent transforming growth factor- binding proteins (LTBPs) are known to modulate TGF- functions. The current study analyses the expression profiles of LTBP4, its isoforms LTBP1 and LTBP3, and TGF-1, TGF-2, TGF-3, and SMAD2, SMAD3 and SMAD4 in human and murine (WAP-TNP8) DCIS compared to invasive mammary tumors. Additionally mammary malignant (MCF7, Hs578T, MDA-MB361) and non malignant cell lines (Hs578BsT) were analysed. Microarray, q-PCR, immunoblot, immunohistochemistry and immunofluorescence were used. In comparison to non-malignant tissues (n = 5), LTBP4 was downregulated in all human and mouse DCIS (n = 9) and invasive mammary adenocarcinomas (n = 5) that were investigated. We also found decreased expression of bone morphogenic protein 4 (BMP4) and increased expression of its inhibitor gremlin (GREM1). Treatment of the mammary tumor cell line (Hs578T) with recombinant TGF-1 rescued BMP4 and GREM1 expression. We conclude that the lack of LTBP4-mediated targeting in malignant mammary tumor tissues may lead to a possible modification of TGF-1 and BMP bioavailability and function

    Targeting the hedgehog transcription factors GLI1 and GLI2 restores sensitivity to vemurafenib-resistant human melanoma cells

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    BRAF inhibitor (BRAFi) therapy for melanoma patients harboring the V600E mutation is initially highly effective, but almost all patients relapse within a few months. Understanding the molecular mechanisms underpinning BRAFi-based therapy is therefore an important issue. Here we identified a previously unsuspected mechanism of BRAFi resistance driven by elevated Hedgehog (Hh) pathway activation that is observed in a cohort of melanoma patients after vemurafenib treatment. Specifically, we demonstrate that melanoma cell lines, with acquired in vitro-induced vemurafenib resistance, show increased levels of glioma-associated oncogene homolog 1 and 2 (GLI1/GLI2) compared with naive cells. We also observed these findings in clinical melanoma specimens. Moreover, the increased expression of the transcription factors GLI1/GLI2 was independent of canonical Hh signaling and was instead correlated with the noncanonical Hh pathway, involving TGF beta/SMAD (transforming growth factor-beta/Sma- and Mad-related family) signaling. Knockdown of GLI1 and GLI2 restored sensitivity to vemurafenib-resistant cells, an effect associated with both growth arrest and senescence. Treatment of vemurafenib-resistant cells with the GLI1/GLI2 inhibitor Gant61 led to decreased invasion of the melanoma cells in a three-dimensional skin reconstruct model and was associated with a decrease in metalloproteinase (MMP2/MMP9) expression and microphthalmia transcription factor upregulation. Gant61 monotherapy did not alter the drug sensitivity of naive cells, but could reverse the resistance of melanoma cells chronically treated with vemurafenib. We further noted that alternating dosing schedules of Gant61 and vemurafenib prevented the onset of BRAFi resistance, suggesting that this could be a potential therapeutic strategy for the prevention of therapeutic escape. Our results suggest that targeting the Hh pathway in BRAFi-resistant melanoma may represent a viable therapeutic strategy to restore vemurafenib sensitivity, reducing or even inhibiting the acquired chemoresistance in melanoma patients.Fapesp-grant number 2012/04194-1, 2013/05172-4, 2014/24400-0 and 2015/10821-7, CNPq-grant number 150447/2013-2 and 471512/2013-3 and PRODOC-grant no 3193-32/2010. Work in the lab of KS Smalley was supported by the National Institutes of Health grants R01 CA161107, R21 CA198550, and Skin SPORE grant P50 CA168536info:eu-repo/semantics/publishedVersio

    High-throughput profiling of caenorhabditis elegans starvation-responsive microRNAs

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    MicroRNAs (miRNAs) are non-coding RNAs of ~22 nucleotides in length that regulate gene expression by interfering with the stability and translation of mRNAs. Their expression is regulated during development, under a wide variety of stress conditions and in several pathological processes. In nature, animals often face feast or famine conditions. We observed that subjecting early L4 larvae from Caenorhabditis elegans to a 12-hr starvation period produced worms that are thinner and shorter than well-fed animals, with a decreased lipid accumulation, diminished progeny, reduced gonad size, and an increased lifespan. Our objective was to identify which of the 302 known miRNAs of C. elegans changed their expression under starvation conditions as compared to well-fed worms by means of deep sequencing in early L4 larvae. Our results indicate that 13 miRNAs (miR-34-3p, the family of miR-35-3p to miR-41-3p, miR-39-5p, miR-41-5p, miR-240-5p, miR-246-3p and miR-4813-5p) were upregulated, while 2 miRNAs (let-7-3p and miR-85-5p) were downregulated in 12-hr starved vs. well-fed early L4 larvae. Some of the predicted targets of the miRNAs that changed their expression in starvation conditions are involved in metabolic or developmental process. In particular, miRNAs of the miR-35 family were upregulated 6-20 fold upon starvation. Additionally, we showed that the expression of gld-1, important in oogenesis, a validated target of miR-35-3p, was downregulated when the expression of miR-35-3p was upregulated. The expression of another reported target, the cell cycle regulator lin-23, was unchanged during starvation. This study represents a starting point for a more comprehensive understanding of the role of miRNAs during starvation in C. elegans

    Impact of intracellular ion channels on cancer development and progression

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