2,897 research outputs found

    Microhomology-mediated mechanisms underlie non-recurrent disease-causing microdeletions of the FOXL2 gene or its regulatory domain

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    Genomic disorders are often caused by recurrent copy number variations (CNVs), with nonallelic homologous recombination (NAHR) as the underlying mechanism. Recently, several microhomology-mediated repair mechanisms-such as microhomology-mediated end-joining (MMEJ), fork stalling and template switching (FoSTeS), microhomology-mediated break-induced replication (MMBIR), serial replication slippage (SRS), and break-induced SRS (BISRS)-were described in the etiology of non-recurrent CNVs in human disease. In addition, their formation may be stimulated by genomic architectural features. It is, however, largely unexplored to what extent these mechanisms contribute to rare, locus-specific pathogenic CNVs. Here, fine-mapping of 42 microdeletions of the FOXL2 locus, encompassing FOXL2 (32) or its regulatory domain (10), serves as a model for rare, locus-specific CNVs implicated in genetic disease. These deletions lead to blepharophimosis syndrome (BPES), a developmental condition affecting the eyelids and the ovary. For breakpoint mapping we used targeted array-based comparative genomic hybridization (aCGH), quantitative PCR (qPCR), long-range PCR, and Sanger sequencing of the junction products. Microhomology, ranging from 1 bp to 66 bp, was found in 91.7% of 24 characterized breakpoint junctions, being significantly enriched in comparison with a random control sample. Our results show that microhomology-mediated repair mechanisms underlie at least 50% of these microdeletions. Moreover, genomic architectural features, like sequence motifs, non-B DNA conformations, and repetitive elements, were found in all breakpoint regions. In conclusion, the majority of these microdeletions result from microhomology-mediated mechanisms like MMEJ, FoSTeS, MMBIR, SRS, or BISRS. Moreover, we hypothesize that the genomic architecture might drive their formation by increasing the susceptibility for DNA breakage or promote replication fork stalling. Finally, our locus-centered study, elucidating the etiology of a large set of rare microdeletions involved in a monogenic disorder, can serve as a model for other clustered, non-recurrent microdeletions in genetic disease

    Small airway remodeling in acute respiratory distress syndrome: a study in autopsy lung tissue

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    Introduction: Airway dysfunction in patients with the Acute Respiratory Distress Syndrome (ARDS) is evidenced by expiratory flow limitation and dynamic hyperinflation. These functional alterations have been attributed to closure/obstruction of small airways. Airway morphological changes have been reported in experimental models of acute lung injury, characterized by epithelial necrosis and denudation in distal airways. To date, however, no study has focused on the morphological airway changes in lungs from human subjects with ARDS. The aim of this study is to evaluate structural and inflammatory changes in distal airways in ARDS patients. Methods: We retrospectively studied autopsy lung tissue from subjects who died with ARDS and from control subjects who died of non pulmonary causes. Using image analysis, we quantified the extension of epithelial changes (normal, abnormal and denudated epithelium expressed as percentages of the total epithelium length), bronchiolar inflammation, airway wall thickness, and extracellular matrix (ECM) protein content in distal airways. The Student`s t test or the Mann-Whitney test was used to compare data between the ARDS and control groups. Bonferroni adjustments were used for multiple tests. The association between morphological and clinical data was analyzed by Pearson rank test. Results: Thirty-one ARDS patients (A: PaO(2)/FiO(2) <= 200, 45 +/- 14 years, 16 males) and 11 controls (C:52 +/- 16 years, 7 males) were included in the study. ARDS airways showed a shorter extension of normal epithelium (A:32.9 +/- 27.2%, C:76.7 +/- 32.7%, P < 0.001), a larger extension of epithelium denudation (A:52.6 +/- 35.2%, C:21.8 +/- 32.1%, P < 0.01), increased airway inflammation (A:1(3), C:0(1), P = 0.03), higher airway wall thickness (A:138.7 +/- 54.3 mu m, C:86.4 +/- 33.3 mu m, P < 0.01), and higher airway content of collagen I, fibronectin, versican and matrix metalloproteinase-9 (MMP-9) compared to controls (P = 0.03). The extension of normal epithelium showed a positive correlation with PaO(2)/FiO(2) (r(2) = 0.34; P = 0.02) and a negative correlation with plateau pressure (r(2) = 0.27; P = 0.04). The extension of denuded epithelium showed a negative correlation with PaO(2)/FiO(2) (r(2) = 0.27; P = 0.04). Conclusions: Structural changes in small airways of patients with ARDS were characterized by epithelial denudation, inflammation and airway wall thickening with ECM remodeling. These changes are likely to contribute to functional airway changes in patients with ARDS.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Laboratorio de Investigacao Medica-LIM05 do Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (LIMHC-FM-USP

    Inequalities in self-rated health: an analysis of the Brazilian and Portuguese populations

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    Objetivou-se analisar a prevalência de saúde autoavaliada como ruim, segundo variáveis sociodemográficas e presença de doença crônica, em populações do Brasil e de Portugal. Foram estudados 13.894 indivíduos (≥ 30 anos) das capitais do Nordeste do Brasil (VIGITEL 2011) e 20.579 de Portugal (4o INS 2005/2006). Utilizou-se a Regressão de Poisson para as análises de associação ajustadas por covariáveis. As prevalências brutas de saúde percebida como ruim, para o Nordeste do Brasil e para Portugal, em homens, foram de 4,3% e de 15,5%. A razão de prevalência (RP) foi de 2,72 (IC95%: 2,70-2,74) após a padronização por faixa etária. Para mulheres, as prevalências foram 8,1%, para o Brasil, e 25,1%, para Portugal (RP: 2,40; IC95%: 2,39-2,42). A variável que revelou desigualdades na saúde autoavaliada como ruim, em maior intensidade, foi a escolaridade, em ambas as populações. A presença de doença teve efeito maior nos brasileiros do que nos portugueses, em ambos os sexos. As prevalências de saúde autoavaliada como ruim foram significativamente mais elevadas para Portugal, em todos os agrupamentos estudados

    Charge effect on the photoinactivation of Gram-negative and Gram-positive bacteria by cationic meso-substituted porphyrins

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    <p>Abstract</p> <p>Background</p> <p>In recent times photodynamic antimicrobial therapy has been used to efficiently destroy Gram (+) and Gram (-) bacteria using cationic porphyrins as photosensitizers. There is an increasing interest in this approach, namely in the search of photosensitizers with adequate structural features for an efficient photoinactivation process. In this study we propose to compare the efficiency of seven cationic porphyrins differing in <it>meso</it>-substituent groups, charge number and charge distribution, on the photodynamic inactivation of a Gram (+) bacterium (<it>Enterococcus faecalis</it>) and of a Gram (-) bacterium (<it>Escherichia coli</it>). The present study complements our previous work on the search for photosensitizers that might be considered good candidates for the photoinactivation of a large spectrum of environmental microorganisms.</p> <p>Results</p> <p>Bacterial suspension (10<sup>7 </sup>CFU mL<sup>-1</sup>) treated with different photosensitizers concentrations (0.5, 1.0 and 5.0 μM) were exposed to white light (40 W m<sup>-2</sup>) for a total light dose of 64.8 J cm<sup>-2</sup>. The most effective photosensitizers against both bacterial strains were the Tri-Py<sup>+</sup>-Me-PF and Tri-Py<sup>+</sup>-Me-CO<sub>2</sub>Me at 5.0 μM with a light fluence of 64.8 J cm<sup>-2</sup>, leading to > 7.0 log (> 99,999%) of photoinactivation. The tetracationic porphyrin also proved to be a good photosensitizer against both bacterial strains. Both di-cationic and the monocationic porphyrins were the least effective ones.</p> <p>Conclusion</p> <p>The number of positive charges, the charge distribution in the porphyrins' structure and the <it>meso</it>-substituent groups seem to have different effects on the photoinactivation of both bacteria. As the Tri-Py<sup>+</sup>-Me-PF porphyrin provides the highest log reduction using lower light doses, this photosensitizer can efficiently photoinactivate a large spectrum of environmental bacteria. The complete inactivation of both bacterial strains with low light fluence (40 W m<sup>-2</sup>) means that the photodynamic approach can be applied to wastewater treatment under natural light conditions which makes this technology cheap and feasible in terms of the light source.</p

    Pulmonary manifestations in a pediatric patient with ulcerative colitis: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Although respiratory involvement has been described in patients with IBD, well-defined interstitial lung disease has not been reported, especially among children with ulcerative colitis.</p> <p>Case presentation</p> <p>Herein, we present a case of an adolescent female with ulcerative colitis and extra-intestinal complications involving the lungs that were effectively treated with anti-metabolite therapy.</p> <p>Conclusion</p> <p>Children with UC may manifest either interstitial or large airway pulmonary involvement. All children with suspected lung involvement should be screened for tuberculosis prior to starting immunosuppressive therapy.</p

    Roadmaps to Utopia: Tales of the Smart City

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    Notions of the Smart City are pervasive in urban development discourses. Various frameworks for the development of smart cities, often conceptualized as roadmaps, make a number of implicit claims about how smart city projects proceed but the legitimacy of those claims is unclear. This paper begins to address this gap in knowledge. We explore the development of a smart transport application, MotionMap, in the context of a £16M smart city programme taking place in Milton Keynes, UK. We examine how the idealized smart city narrative was locally inflected, and discuss the differences between the narrative and the processes and outcomes observed in Milton Keynes. The research shows that the vision of data-driven efficiency outlined in the roadmaps is not universally compelling, and that different approaches to the sensing and optimization of urban flows have potential for empowering or disempowering different actors. Roadmaps tend to emphasize the importance of delivering quick practical results. However, the benefits observed in Milton Keynes did not come from quick technical fixes but from a smart city narrative that reinforced existing city branding, mobilizing a growing network of actors towards the development of a smart region. Further research is needed to investigate this and other smart city developments, the significance of different smart city narratives, and how power relationships are reinforced and constructed through them
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