4,099 research outputs found

    Modulation of iron metabolism in response to infection: Twists for all tastes

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    Iron is an essential nutrient for almost all living organisms, but is not easily made available. Hosts and pathogens engage in a fight for the metal during an infection, leading to major alterations in the host’s iron metabolism. Important pathological consequences can emerge from the mentioned interaction, including anemia. Several recent reports have highlighted the alterations in iron metabolism caused by different types of infection, and several possible therapeutic strategies emerge, based on the targeting of the host’s iron metabolism. Here, we review the most recent literature on iron metabolism alterations that are induced by infection, the consequent development of anemia, and the potential therapeutic approaches to modulate iron metabolism in order to correct iron-related pathologies and control the ongoing infection.This work is a result of the project Norte-01-0145-FEDER-000012-Structured program on bioengineered therapies for infectious diseases and tissue regeneration, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work was financed by FEDER-Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020-Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT-Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/IMI-MIC/1683/2014 (POCI-01-0145-FEDER-016590). A.C.M. receives the individual fellowship SFRH/BPD/101405/2014 from FCT

    The crossroads between infection and bone loss

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    Bone homeostasis, based on a tight balance between bone formation and bone degradation, is affected by infection. On one hand, some invading pathogens are capable of directly colonizing the bone, leading to its destruction. On the other hand, immune mediators produced in response to infection may dysregulate the deposition of mineral matrix by osteoblasts and/or the resorption of bone by osteoclasts. Therefore, bone loss pathologies may develop in response to infection, and their detection and treatment are challenging. Possible biomarkers of impaired bone metabolism during chronic infection need to be identified to improve the diagnosis and management of infection-associated osteopenia. Further understanding of the impact of infections on bone metabolism is imperative for the early detection, prevention, and/or reversion of bone loss. Here, we review the mechanisms responsible for bone loss as a direct and/or indirect consequence of infection.This article is a result of the project HEALTH-UNORTE: Setting-up biobanks and regenerative medicine strategies to boost research in cardiovascular, musculoskeletal, neurological, oncological, immunologicalm, and infectious diseases (NORTE-01-0145-FEDER-000039), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). A.C.G. is supported by a Junior Investigator Contract under the program CEEIND2017, from Fundação para a Ciência e Tecnologia (Portugal)

    Regeneration of the peripheral nerve - Development and evaluation of guide tubes of biodegradable polymer

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    Damage to peripheral nerve fibers results in axonal loss and demyelination followed by regeneration and remyelination under optimal conditions with the possibility of some functional recovery. The experimental challenge is to accelerate axonal regeneration to promote reinnervation and improve functional recovery after peripheral nerve injury. In the past few decades, different types of biological or artificial guide tubes have been developed to bridge the gap of a sectioned nerve, to limit the fibrosis process and to orient the regenerating fibers towards the distal stump. Chitosan is widely used for biomedical applications, including crosslinked with other materials. In this work, chitosan guide tubes were produced and implanted using the rat sciatic nerve animal model. Functional tests were performed as well as a mechanical and structural characterization of the guide tubes. (c) 2017 IEEE

    H-Ferritin Is Essential for Macrophages' Capacity to Store or Detoxify Exogenously Added Iron

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    Macrophages are central cells both in the immune response and in iron homeostasis. Iron is both essential and potentially toxic. Therefore, iron acquisition, transport, storage, and release are tightly regulated, by several important proteins. Cytosolic ferritin is an iron storage protein composed of 24 subunits of either the L- or the H-type chains. H-ferritin differs from L-ferritin in the capacity to oxidize Fe2+ to Fe3+. In this work, we investigated the role played by H-ferritin in the macrophages' ability to respond to immune stimuli and to deal with exogenously added iron. We used mice with a conditional deletion of the H-ferritin gene in the myeloid lineage to obtain bone marrow-derived macrophages. These macrophages had normal viability and gene expression under basal culture conditions. However, when treated with interferon-gamma and lipopolysaccharide they had a lower activation of Nitric Oxide Synthase 2. Furthermore, H-ferritin-deficient macrophages had a higher sensitivity to iron-induced toxicity. This sensitivity was associated with a lower intracellular iron accumulation but a higher production of reactive oxygen species. These data indicate that H-ferritin modulates macrophage response to immune stimuli and that it plays an essential role in protection against iron-induced oxidative stress and cell death.Tis work was fnanced by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE2020 - Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/IMI-MIC/1683/2014 (POCI-01-0145-FEDER-016590). PFO and MGA acknowledge FCT for the Investigador FCT 2015. We thank the valuable collaboration of the following i3S Scientifc Platforms: Cell Culture and Genotyping Core Facility (CCGen), [Histology and Electron Microscopy Service (HEMS), and BioSciences Screening], member of the PPBI (PPBI-POCI-01-0145-FEDER-022122)], Animal Facility, and Flow Cytometry Unit (TraCy). We acknowledge Lukas Kuhn (Swiss Institute for Experimental Cancer Research, Lausanne, Switzerland) for kindly providing the frst breeding pairs of Fth1−/− mice. Te authors also acknowledge Marisa Castro, from Departamento de Biologia Molecular from ICBAS, Clara Bento, from i3S, and Edgar Pinto from LAQV – REQUIMTE for technical assistance at diferent stages of the project

    Trends in sugar content of non-alcoholic beverages in Australia between 2015 and 2019 during the operation of a voluntary industry pledge to reduce sugar content

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    Objectives: To investigate changes in mean sugar content of non-alcoholic beverages (overall and sugar-sweetened beverages) available for purchase in Australia and to compare signatories versus non-signatories of the Australian Beverages Council voluntary pledge from 2018 Design: Retrospective observational study Setting: Australia Participants: About 1,500 non-alcoholic beverages per year included in the FoodSwitch Monitoring Datasets for 2015-2019 Results: Overall, mean sugar content fell by 1.3g/100mL (17.1%) from 7.5g/100mL in 2015 to 6.2g/100mL in 2019. SSBs have accounted for about 56% of all beverages available for purchase since 2015. Between 2015 and 2019, the sugar content of SSBs dropped by about 10% (0.8g/100mL). Soft drinks and milk-based drinks were the categories with the largest decrease in sugar content. The greater reduction in sugar observed for beverages overall than SSBs suggests at least some of the overall decrease in sugar content is due to the appearance of new products with low or no-sugar rather than reformulation. Over the same period, beverages with added non-nutritive sweeteners increased from 41% to 44%. The decrease in sugar content for all beverages and SSBs was, in general, larger for non-signatories than signatories of the voluntary industry pledge. Conclusions: Between 2015 and 2019, the small reduction in sugar content of non-alcoholic beverages in Australia resulted from the combined effects of introducing low or no-sugar products and reformulation of some categories of SSBs. Further policy and regulatory measures are required to reap the most benefit that sugar reduction among non-alcoholic beverages can bring to population health

    Women's representation as authors of retracted papers in the biomedical sciences

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    Women are under-represented among authors of scientific papers. Although the number of retractions has been rising over the past few decades, gender differences among authors of retracted papers remain poorly understood. Therefore, this study investigated gender differences in authorship of retracted papers in biomedical sciences available on Retraction- Watch. Among 35,635 biomedical articles retracted between 1970 and 2022, including 20,849 first authors and 20,413 last authors, women accounted for 27.4% [26.8 to 28.0] of first authors and 23.5% [22.9 to 24.1] of last authors. The lowest representation of women was found for fraud (18.9% [17.1 to 20.9] for first authors and 13.5% [11.9 to 15.1] for last authors) and misconduct (19.5% [17.3 to 21.9] for first authors and 17.8% [15.7 to 20.3] for last authors). Women's representation was the highest for issues related to editors and publishers (35.1% [32.2 to 38.0] for first authors and 24.8% [22.9 to 26.8] for last authors) and errors (29.5% [28.0 to 31.0] for first authors and 22.1% [20.7 to 23.4] for last authors). Most retractions (60.9%) had men as first and last authors. Gender equality could improve research integrity in biomedical sciences

    Public perceptions of responsibility for recommended food policies in seven countries

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    Background: Food policy is important to promote healthy and sustainable diets. However, who is responsible for developing and implementing food policy remains contentious. Therefore, this study aimed to investigate how the public attributes responsibility for food policy to governments, individuals and the private sector. Methods: A total of 7559 respondents from seven countries [Australia (n = 1033), Canada (n = 1079), China (n = 1099), India (n = 1086), New Zealand (n = 1090), the UK (n = 1079) and the USA (n = 1093)] completed an online survey assessing perceived responsibility for 11 recommended food policies. Results: Overall, preferred responsibility for the assessed food policies was primarily attributed to governments (62%), followed by the private sector (49%) and individuals (31%). Respondents from New Zealand expressed the highest support for government responsibility (70%) and those from the USA the lowest (50%). Respondents from the USA and India were most likely to nominate individuals as responsible (both 37%), while those from China were least likely (23%). The private sector had the highest attributed responsibility in New Zealand (55%) and the lowest in China and the USA (both 47%). Support for government responsibility declined with age and was higher among those on higher incomes, with a university degree, and who perceived themselves to consume a healthy diet or be in poor health. Conclusions: Across seven diverse countries, results indicate the public considers government should take primary responsibility for the assessed food policies, with modest contribution from the private sector and minority support for individual responsibility

    Determination of sulfur dioxide in wine using a quartz crystal microbalance

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    A new method for the analysis of both total and bound SO2 in wine is proposed, based on a quartz crystal microbalance (QCM), and it is compared with the widely used Ripper method. The proposed method is faster than the Ripper's, and the instrumentation is either homemade or widely available. When both methods are applied to the same sample, the results obtained using the QCM method are bracketed in an interval less than one-tenth the size of that obtained using the Ripper method. Although the SO2 concentrations found using the QCM method correlate well with the ones obtained with the Ripper method, the results are systematically higher, which can be explained as due to the absence of interferences known to affect the Ripper method

    Biotin-avidin sandwich elisa with specific human isotypes IgG1 and IgG4 for Culicidae mosquito blood meal identification from an epizootic yellow fever area in Brazil

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    With a view toward investigating the feeding behavior of Culicidae mosquitoes from an area of epizootic yellow fever transmission in the municipalities of Garruchos and Santo Antônio das Missões, Rio Grande do Sul State, Brazil, specimens were collected by aspiration from September 2005 to April 2007. The engorged females were submitted to blood meal identification by enzyme-linked immunosorbent assay (ELISA). A total of 142 blood-engorged samples were examined for human or monkey blood through species-specific IgG. Additional tests for specificity utilizing isotypes IgG1 and IgG4 of human monoclonal antibodies showed that only anti-human IgG1 was effective in recognizing blood meals of human origin. The results indicated a significant difference (p = 0.027) in detection patterns in samples of Haemagogus leucocelaenus recorded from human blood meals at Santo Antônio das Missões, which suggests some degree of exposure, since it was an area where epizootic outbreaks have been reported.PAHO Pan American Health Organization - Secretary of Health Surveillance, Brazilian Ministry of Healt
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