259 research outputs found

    The podocyte cytoskeleton in health and in disease

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    The podocyte is a key cell in the selective filtering action of the glomerular capillary wall. Podocyte injury is of pathogenetic and prognostic significance in human glomerular disease; podocyte repair and regeneration are important therapeutic targets. In particular, podocyte function is dependent on the cells' actin cytoskeleton: this maintains their complex structure. Alterations in the actin cytoskeleton arise from a variety of genetic and acquired causes. Therapeutic agents that are beneficial in proteinuric disease may act at least partly by restoring the cell shape via effects on the actin cytoskeleton. Recent studies of podocytes in vivo and in vitro are described, highlighting clinically relevant observations and those that help us understand the ways in which we may harness nature's own mechanisms to repair and/or renew these specialized glomerular cells, with a particular focus on their actin cytoskeleton. Drugs that have beneficial effects on podocytes can improve our ability to treat important renal diseases including diabetic nephropathy. Currently available agents can be applied in this way and the rapid progress in the study of podocytes is highlighting new therapeutic targets that can bring even more specificity. © 2012 The Author.published_or_final_versio

    REGULATORY ROLE OF OX22HIGH T-CELLS IN MERCURY-INDUCED AUTOIMMUNITY IN THE BROWN NORWAY RAT

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    The monoclonal antibody OX22 defines a functional split within CD4+ T cells in the rat, with OX22high cells mainly producing interleukin 2 (IL-2) and interferon γ and responsible for delayed-type hypersensitivity responses, and OX22low cells mainly producing IL-4 and -5 and responsible for providing B cell help. There are reciprocal interactions between OX22high and OX22low cells, and it has been suggested that the OX22low subset has a role in the prevention of autoimmunity. We have used OX22 in vivo to define the role of these subsets in mercuric chloride-induced autoimmunity in the Brown Norway rat. In this model, there is polyclonal B cell activation and animals develop widespread tissue injury. Treatment of thymectomized animals with OX22 led to a profound reduction in the number of OX22high T cells in the peripheral blood. OX22-treated animals consistently developed more severe tissue injury than controls given an irrelevant antibody of the same isotype. Control animals pretreated with broad spectrum antimicrobial drugs showed milder tissue injury, but this protective effect of antimicrobials was lost in OX22-treated animals. Transfer of naive T cells to OX22-treated animals provided protection, but if T cells were depleted in vitro of OX22high cells before transfer, this effect was lost. These data provide evidence for a protective immunoregulatory role for OX22high T cells in mercuric chloride-induced autoimmunity.link_to_subscribed_fulltex

    COMPLEMENT-MEDIATED ADIPOCYTE LYSIS BY NEPHRITIC FACTOR SERA

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    Recent data indicate a previously unsuspected link between the complement system and adipocyte biology. Murine adipocytes produce key components of the alternative pathway of complement and are able to activate this pathway. This suggested to us an explanation for adipose tissue loss in partial lipodystrophy, a rare human condition usually associated with the immunoglobulin G(IgG) autoantibody nephritic factor (NeF) which leads to enhanced alternative pathway activation in vivo. We hypothesized that in the presence of NeF, there is dysregulated complement activation at the membrane of the adipocyte, leading to adipocyte lysis. Here we show that adipocytes explanted from rat epididymal fat pads are lysed by NeF-containing sera but not by control sera. A similar pattern is seen with IgG fractions of these sera. Adipocyte lysis in the presence of NeF is associated with the generation of fluid-phase terminal complement complexes, the level of which correlates closely with the level of lactate dehydrogenase, a marker of cell lysis. Lysis is abolished by ethylenediaminetetraacetic acid, which chelates divalent cations and prevents complement activation, and reduced by an antibody to factor D, a key component of the alternative pathway. These data provide an explanation for the previously obscure link between NeF and fat cell damage

    Uso de fontes em aulas de História e conciência histórica: encaminhamentos e discussões teóricas

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    Anais do XVII Congresso Internacional das Jornadas de Educaão História - teoria, pesquisa e prática - I Encontro da AIPEDH - Associação Iber-Americana de Pesquisadores em Educação História, realizado pela Universidade Federal da Integração Latino-Americana, entre 02, 03 e 04 de agosto de 2017.Este trabalho apresenta os encaminhamentos de uma pesquisa iniciada no curso de graduação em História na Universidade Estadual de Londrina, e prossegue como parte das discussões que estão sendo realizadas no Mestrado do Programa de Pós-Graduação em Educação da mesma universidade, sob orientação da Professora Dra. Marlene Rosa Cainelli. A investigação realizada tem como objetivo principal o estudo do uso de fontes no ensino de história, mais especificamente sobre a literatura em aulas de história na perspectiva da Educação Histórica, tendo como tema adaptações do clássico “Os Miseráveis”, de Victor Hugo. A pesquisa atual trata do uso de uma versão em História em Quadrinhos (HQ) da obra, buscando verificar como HQs podem contribuir para o desenvolvimento da consciência histórica dos alunos. Para tanto, utilizamo-nos, entre outros, dos escritos de Rüsen (2011) sobre a consciência histórica e Fronza (2007, 2012) sobre o uso de quadrinhos relacionados a temáticas históricasCAPE

    Stage 1 Development of a Patient Reported Experience Measure (PREM) for Chronic Obstructive Pulmonary Disease (COPD)

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    The study aimed to explore patients’ experience of living with COPD and their perspective of their community health care for COPD to extract affective responses in order to develop potential items for a patient reported experience measure (PREM) for Chronic Obstructive Pulmonary Disease (COPD). Qualitative face-face interviews were conducted, in the community, with 64 patients with COPD recruited from General Practices and Breath-Easy community groups in the Outer North East, East and City, London and Essex, UK. A two phase analysis of the qualitative data was conducted to identify themes arising from patients’ description of living with COPD and their perceptions of their community health care and subsequently the affective responses underlying the themes raised by patients, which gave emotional colour to the themes, bringing the thematic analysis closer to the subjective patient experience. Five themes were identified from the interview data: ‘Journey to diagnosis’; ‘Smoking’; ‘Usual care’; ‘My everyday life’; and ‘Exacerbations’. Twenty affective responses were identified and categorised as either ‘negative’, ‘positive’ or ‘bivalent’. ‘Frustration’, a negative affective response was prevalent in four themes. ‘Gratitude’, ‘hope’ and ‘happiness/enjoyment’ were among the more positive responses more prevalent across several themes. By conducting a novel two-way analysis (thematic and affective) it was possible to identify themes and affective responses that were aligned to those themes. This enabled the development of 38 COPD specific experience items to take forward for further testing including item reduction and validity and reliability in the next stage of the PREM development

    Reactive Oxygen Species Modulate the Barrier Function of the Human Glomerular Endothelial Glycocalyx

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    Reactive oxygen species (ROS) play a key role in the pathogenesis of proteinuria in glomerular diseases like diabetic nephropathy. Glomerular endothelial cell (GEnC) glycocalyx covers the luminal aspect of the glomerular capillary wall and makes an important contribution to the glomerular barrier. ROS are known to depolymerise glycosaminoglycan (GAG) chains of proteoglycans, which are crucial for the barrier function of GEnC glycocalyx. The aim of this study is to investigate the direct effects of ROS on the structure and function of GEnC glycocalyx using conditionally immortalised human GEnC. ROS were generated by exogenous hydrogen peroxide. Biosynthesis and cleavage of GAG chains was analyzed by radiolabelling (S35 and 3H-glucosamine). GAG chains were quantified on GEnC surface and in the cell supernatant using liquid chromatography and immunofluorescence techniques. Barrier properties were estimated by measuring trans-endothelial passage of albumin. ROS caused a significant loss of WGA lectin and heparan sulphate staining from the surface of GEnC. This lead to an increase in trans-endothelial albumin passage. The latter could be inhibited by catalase and superoxide dismutase. The effect of ROS on GEnC was not mediated via the GAG biosynthetic pathway. Quantification of radiolabelled GAG fractions in the supernatant confirmed that ROS directly caused shedding of HS GAG. This finding is clinically relevant and suggests a mechanism by which ROS may cause proteinuria in clinical conditions associated with high oxidative stress. © 2013 Singh et al.published_or_final_versio

    Filtro natural aplicado ao tratamento da água na comunidade indígena de Killuyacu Alto - Equador

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    Trabalho de Conclusão de Curso apresentado à Banca Examinadora do Curso de Engenharia Civil de Infraestrutura da UNILA, como parte dos requisitos para obtenção do Grau de Bacharel em Engenharia Civil. Orientador: Profo. Dro. Jiam Pires Frigo Co-orientadora: Profo. Samara Silva de SouzaO filtro natural aplicado ao tratamento da água pluvial na comunidade indígena de Killuyacu Alto na província de Napo no Equador tem como finalidade melhorar a qualidade da água para consumo humano através da proposta de um sistema de filtragem natural lento de baixo custo e instalação simples. A água usada atualmente para consumo da comunidade Killuyacu Alto é captada num manancial localizada numa caverna á montante, armazenada e transportada por gravidade até a comunidade sem passar por nenhum tratamento. O estudo visa promover soluções para o consumo de água potável na região amazônica do Equador, melhorar a saúde nas povoações mais vulneráveis do território amazônico, através de um tratamento de água simplificado, e além disso, reduzir as doenças provocadas pelo consumo de água de baixa qualidade. Para isso, foi realizado um estúdio socioeconômico e levantamento de dados na comunidade, extração e coletas de amostras de água no sistema de abastecimento, análise e avaliação dos padrões de potabilidade antes e depois da implantação do filtro natural para a comparação da qualidade da água. O projeto forneceu uma melhoria na qualidade da água pela implantação do sistema de filtragem natural lenta, embora não foi possível atingir a qualidade necessária para o consumo humano.The natural filter applied to the treatment of rainwater in the indigenous community of Killuyacu Alto in the province of Napo in Ecuador aims to improve the quality of water for human consumption through the proposal of a slow natural filtration system of low cost and simple installation. The water currently used for consumption by the Killuyacu Alto community is taken from a source located in an upstream cave, stored and transported by gravity to the community without undergoing any water treatment. The study promoted solutions for the consumption of drinking water in the Amazonian region of Ecuador and improve health in the most vulnerable settlements in the Amazonian territory through a simplified water treatment and also reduce diseases caused by the consumption of low quality water. For this, a socioeconomic study and community data collection, extraction and collection of water samples were carried out in the supply system, the potability standards were analyzed and evaluated before and after the implantation of the natural filter, if we compare the quality of the water. The project provided an improvement in water quality through the implementation of the slow natural filtration system, although it was not possible to reach the required quality for human consumption

    Complement in glomerular injury

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    In recent years, research into the role of complement in the immunopathogenesis of renal disease has broadened our understanding of the fragile balance between the protective and harmful functions of the complement system. Interventions into the complement system in various models of immune-mediated renal disease have resulted in both favourable and unfavourable effects and will allow us to precisely define the level of the complement cascade at which a therapeutic intervention will result in an optimal effect. The discovery of mutations of complement regulatory molecules has established a role of complement in the haemolytic uremic syndrome and membranoproliferative glomerulonephritis, and genotyping for mutations of the complement system are already leaving the research laboratory and have entered clinical practice. These clinical discoveries have resulted in the creation of relevant animal models which may provide crucial information for the development of highly specific therapeutic agents. Research into the role of complement in proteinuria has helped to understand pathways of inflammation which ultimately lead to renal failure irrespective of the underlying renal disease and is of major importance for the majority of renal patients. Complement science is a highly exciting area of translational research and hopefully will result in meaningful therapeutic advances in the near future

    Idiopathic pulmonary fibrosis

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    Idiopathic pulmonary fibrosis (IPF) is a non-neoplastic pulmonary disease that is characterized by the formation of scar tissue within the lungs in the absence of any known provocation. IPF is a rare disease which affects approximately 5 million persons worldwide. The prevalence is estimated to be slightly greater in men (20.2/100,000) than in women (13.2/100,000). The mean age at presentation is 66 years. IPF initially manifests with symptoms of exercise-induced breathless and dry coughing. Auscultation of the lungs reveals early inspiratory crackles, predominantly located in the lower posterior lung zones upon physical exam. Clubbing is found in approximately 50% of IPF patients. Cor pulmonale develops in association with end-stage disease. In that case, classic signs of right heart failure may be present. Etiology remains incompletely understood. Some environmental factors may be associated with IPF (cigarette smoking, exposure to silica and livestock). IPF is recognized on high-resolution computed tomography by peripheral, subpleural lower lobe reticular opacities in association with subpleural honeycomb changes. IPF is associated with a pathological lesion known as usual interstitial pneumonia (UIP). The UIP pattern consists of normal lung alternating with patches of dense fibrosis, taking the form of collagen sheets. The diagnosis of IPF requires correlation of the clinical setting with radiographic images and a lung biopsy. In the absence of lung biopsy, the diagnosis of IPF can be made by defined clinical criteria that were published in guidelines endorsed by several professional societies. Differential diagnosis includes other idiopathic interstitial pneumonia, connective tissue diseases (systemic sclerosis, polymyositis, rheumatoid arthritis), forme fruste of autoimmune disorders, chronic hypersensitivity pneumonitis and other environmental (sometimes occupational) exposures. IPF is typically progressive and leads to significant disability. The median survival is 2 to 5 years from the time of diagnosis. Medical therapy is ineffective in the treatment of IPF. New molecular therapeutic targets have been identified and several clinical trials are investigating the efficacy of novel medication. Meanwhile, pulmonary transplantation remains a viable option for patients with IPF. It is expected that, during the next decade, considerable progress will be made toward the understanding and treatment of this devastating illness

    Molecular genetic analysis of podocyte genes in focal segmental glomerulosclerosis—a review

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    This review deals with podocyte proteins that play a significant role in the structure and function of the glomerular filter. Genetic linkage studies has identified several genes involved in the development of nephrotic syndrome and contributed to the understanding of the pathophysiology of glomerular proteinuria and/or focal segmental glomerulosclerosis. Here, we describe already well-characterized genetic diseases due to mutations in nephrin, podocin, CD2AP, alpha-actinin-4, WT1, and laminin β2 chain, as well as more recently identified genetic abnormalities in TRPC6, phospholipase C epsilon, and the proteins encoded by the mitochondrial genome. In addition, the role of the proteins which have shown to be important for the structure and functions by gene knockout studies in mice, are also discussed. Furthermore, some rare syndromes with glomerular involvement, in which molecular defects have been recently identified, are briefly described. In summary, this review updates the current knowledge of genetic causes of congenital and childhood nephrotic syndrome and provides new insights into mechanisms of glomerular dysfunction
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