177 research outputs found

    Génie végétal contre l'érosion des berges de cours d'eau dans un contexte de changement climatique : quelles nouvelles espÚces utiliser ?

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    National audienceL'érosion des berges est un phénomÚne naturel participant activement aux processus de dynamique fluviale. Toutefois, afin de protéger des enjeux riverains (habitations, infrastructures de transport,) il est parfois nécessaire de fixer les berges avec des ouvrages de protection. Pour se faire, le génie végétal est aujourd'hui de plus en plus employé. Il s'agit de mettre en place des matériaux végétaux vivants qui vont stabiliser les berges. Ces ouvrages comprennent notamment des boutures de saules, dont les racines vont fixer la zone érodée. Les saules, sont des espÚces qui apprécient l'eau et restent inféodées à la nappe phréatique. Or la sécheresse est une des causes majeures d'échec des ouvrages de génie végétal, et ces derniÚres devraient s'aggraver avec le changement climatique. Il apparaßt donc particuliÚrement intéressant de tester de nouvelles espÚces présentant à la fois de bonnes capacités en termes de génie végétal et une meilleure résistance à la sécheresse. Myricaria germanica et Tamarix gallica, deux espÚces pionniÚres des bords de cours d'eau, présentent à priori de telles caractéristiques, mais leurs patrons de développement ainsi que leur capacité de résistance à la sécheresse sont peu connues. Les comportements de boutures de ces deux espÚces ont été comparés avec celle d'un saule dans trois expérimentations en laboratoire et sur le terrain. On a ainsi pu déterminer les dynamiques de croissance des parties aériennes et souterraines en fonction de différentes modalités de sécheresse. Myricaria germanica et Tamarix gallica montrent généralement un taux de reprise au bouturage élevé et proche de celui du saule, et un investissement dans les racines supérieur en cas de sécheresse, Cependant la croissance de Myricaria germanica apparaßt nettement plus faible que celles des deux autres espÚces Ces deux espÚces présentent un fort potentiel pour le génie végétal, notamment dans un contexte de changement climatique. Elles s'adaptent bien aux conditions de sÚcheresse et disposent de bonnes capacités de stabilisation. Leur utilisation dans ce domaine devrait contribuer à augmenter la biodiversité des ouvrages

    Structure and computation-guided yeast surface display for the evolution of TIMP-based matrix metalloproteinase inhibitors

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    The study of protein-protein interactions (PPIs) and the engineering of protein-based inhibitors often employ two distinct strategies. One approach leverages the power of combinatorial libraries, displaying large ensembles of mutant proteins, for example, on the yeast cell surface, to select binders. Another approach harnesses computational modeling, sifting through an astronomically large number of protein sequences and attempting to predict the impact of mutations on PPI binding energy. Individually, each approach has inherent limitations, but when combined, they generate superior outcomes across diverse protein engineering endeavors. This synergistic integration of approaches aids in identifying novel binders and inhibitors, fine-tuning specificity and affinity for known binding partners, and detailed mapping of binding epitopes. It can also provide insight into the specificity profiles of varied PPIs. Here, we outline strategies for directing the evolution of tissue inhibitors of metalloproteinases (TIMPs), which act as natural inhibitors of matrix metalloproteinases (MMPs). We highlight examples wherein design of combinatorial TIMP libraries using structural and computational insights and screening these libraries of variants using yeast surface display (YSD), has successfully optimized for MMP binding and selectivity, and conferred insight into the PPIs involved

    Decreasing recurrent bowel obstructions, improving quality of life with physiotherapy: Controlled study

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    AIM: To compare (1) quality of life and (2) rate of recurrent small bowel obstructions (SBO) for patients treated with novel manual physiotherapy METHODS: One hundred and three subjects (age 19-89) with a history of recurrent adhesive SBO were treated with a manual physiotherapy called the Clear Passage Approach (CPA) which focused on decreasing adhesive crosslinking in abdominopelvic viscera. Pre- and post-therapy data measured recurring obstructions and quality of life, using a validated test sent 90 d after therapy. Results were compared to 136 untreated control subjects who underwent the same measurements for subjects who did not receive any therapy, which is the normal course for patients with recurring SBO. Comparison of the groups allowed us to assess changes when the physiotherapy was added as an adjunct treatment for patients with recurring SBO. RESULTS: Despite histories of more prior hospitalizations, obstructions, surgeries, and years impacted by bowel issues, the 103 CPA-treated subjects reported a significantly lower rate of repeat SBO than 136 untreated controls (total obstructions CONCLUSION: CPA physical therapy was effective for patients with adhesive SBO with significantly lower recurrence rate, improvement in reported symptoms and overall quality of life of subjects

    Manipulating the microbiome : an alternative treatment for bile acid diarrhoea

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    Bile acid diarrhoea (BAD) is a widespread gastrointestinal disease that is often misdiagnosed as irritable bowel syndrome and is estimated to affect 1% of the United Kingdom (UK) population alone. BAD is associated with excessive bile acid synthesis secondary to a gastrointestinal or idiopathic disorder (also known as primary BAD). Current licensed treatment in the UK has undesirable effects and has been the same since BAD was first discovered in the 1960s. Bacteria are essential in transforming primary bile acids into secondary bile acids. The profile of an individual’s bile acid pool is central in bile acid homeostasis as bile acids regulate their own synthesis. Therefore, microbiome dysbiosis incurred through changes in diet, stress levels and the introduction of antibiotics may contribute to or be the cause of primary BAD. This literature review focuses on primary BAD, providing an overview of bile acid metabolism, the role of the human gut microbiome in BAD and the potential options for therapeutic intervention in primary BAD through manipulation of the microbiome

    Gene content evolution in the arthropods

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    Arthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality, and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity

    Physician support for diabetes patients and clinical outcomes

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    <p>Abstract</p> <p>Background</p> <p>Physician practical support (e.g. setting goals, pro-active follow-up) and communicative support (e.g., empathic listening, eliciting preferences) have been hypothesized to influence diabetes outcomes.</p> <p>Methods</p> <p>In a prospective observational study, patients rated physician communicative and practical support using a modified Health Care Climate Questionnaire. We assessed whether physicians' characteristic level of practical and communicative support (mean across patients) and each patients' deviation from their physician's mean level of support was associated with glycemic control outcomes. Glycosylated haemoglobin (HbA1c) levels were measured at baseline and at follow-up, about 2 years after baseline.</p> <p>Results</p> <p>We analysed 3897 patients with diabetes treated in nine primary care clinics by 106 physicians in an integrated health plan in Western Washington, USA. Physicians' average level of practical support (based on patient ratings of their provider) was associated with significantly lower HbA1c at follow-up, controlling for baseline HbA1c (<it>p </it>= .0401). The percentage of patients with "optimal" and "poor" glycemic control differed significantly across different levels of practical support at follow (<it>p </it>= .022 and <it>p </it>= .028). Communicative support was not associated with differences in HbA1c at follow-up.</p> <p>Conclusion</p> <p>This observational study suggests that, in community practice settings, physician differences in practical support may influence glycemic control outcomes among patients with diabetes.</p

    Matrix Metalloproteinase-10 Is Required for Lung Cancer Stem Cell Maintenance, Tumor Initiation and Metastatic Potential

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    Matrix metalloproteinases (Mmps) stimulate tumor invasion and metastasis by degrading the extracellular matrix. Here we reveal an unexpected role for Mmp10 (stromelysin 2) in the maintenance and tumorigenicity of mouse lung cancer stem-like cells (CSC). Mmp10 is highly expressed in oncosphere cultures enriched in CSCs and RNAi-mediated knockdown of Mmp10 leads to a loss of stem cell marker gene expression and inhibition of oncosphere growth, clonal expansion, and transformed growth in vitro. Interestingly, clonal expansion of Mmp10 deficient oncospheres can be restored by addition of exogenous Mmp10 protein to the culture medium, demonstrating a direct role for Mmp10 in the proliferation of these cells. Oncospheres exhibit enhanced tumor-initiating and metastatic activity when injected orthotopically into syngeneic mice, whereas Mmp10-deficient cultures show a severe defect in tumor initiation. Conversely, oncospheres implanted into syngeneic non-transgenic or Mmp10−/− mice show no significant difference in tumor initiation, growth or metastasis, demonstrating the importance of Mmp10 produced by cancer cells rather than the tumor microenvironment in lung tumor initiation and maintenance. Analysis of gene expression data from human cancers reveals a strong positive correlation between tumor Mmp10 expression and metastatic behavior in many human tumor types. Thus, Mmp10 is required for maintenance of a highly tumorigenic, cancer-initiating, metastatic stem-like cell population in lung cancer. Our data demonstrate for the first time that Mmp10 is a critical lung cancer stem cell gene and novel therapeutic target for lung cancer stem cells

    Matrix Metalloproteinase-Induced Epithelial-Mesenchymal Transition in Breast Cancer

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    Matrix metalloproteinases (MMPs) degrade and modify the extracellular matrix (ECM) as well as cell-ECM and cell-cell contacts, facilitating detachment of epithelial cells from the surrounding tissue. MMPs play key functions in embryonic development and mammary gland branching morphogenesis, but they are also upregulated in breast cancer, where they stimulate tumorigenesis, cancer cell invasion and metastasis. MMPs have been investigated as potential targets for cancer therapy, but clinical trials using broad-spectrum MMP inhibitors yielded disappointing results, due in part to lack of specificity toward individual MMPs and specific stages of tumor development. Epithelial-mesenchymal transition (EMT) is a developmental process in which epithelial cells take on the characteristics of invasive mesenchymal cells, and activation of EMT has been implicated in tumor progression. Recent findings have implicated MMPs as promoters and mediators of developmental and pathogenic EMT processes in the breast. In this review, we will summarize recent studies showing how MMPs activate EMT in mammary gland development and in breast cancer, and how MMPs mediate breast cancer cell motility, invasion, and EMT-driven breast cancer progression. We also suggest approaches to inhibit these MMP-mediated malignant processes for therapeutic benefit

    Bringing the margin to the focus: 10 challenges for riparian vegetation science and management

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    Riparian zones are the paragon of transitional ecosystems, providing critical habitat and ecosystem services that are especially threatened by global change. Following consultation with experts, 10 key challenges were identified to be addressed for riparian vegetation science and management improvement: (1) Create a distinct scientific community by establishing stronger bridges between disciplines; (2) Make riparian vegetation more visible and appreciated in society and policies; (3) Improve knowledge regarding biodiversity—ecosystem functioning links; (4) Manage spatial scale and context-based issues; (5) Improve knowledge on social dimensions of riparian vegetation; (6) Anticipate responses to emergent issues and future trajectories; (7) Enhance tools to quantify and prioritize ecosystem services; (8) Improve numerical modeling and simulation tools; (9) Calibrate methods and increase data availability for better indicators and monitoring practices and transferability; and (10) Undertake scientific validation of best management practices. These challenges are discussed and critiqued here, to guide future research into riparian vegetation
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