117 research outputs found

    Kidney organ donation: developing family practice initiatives to reverse inertia

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    <p>Abstract</p> <p>Background</p> <p>Kidney transplantation is associated with greater long term survival rates and improved quality of life compared with dialysis. Continuous growth in the number of patients with kidney failure has not been matched by an increase in the availability of kidneys for transplantation. This leads to long waiting lists, higher treatment costs and negative health outcomes.</p> <p>Discussion</p> <p>Misunderstandings, public uncertainty and issues of trust in the medical system, that limit willingness to be registered as a potential donor, could be addressed by community dissemination of information and new family practice initiatives that respond to individuals' personal beliefs and concerns regarding organ donation and transplantation.</p> <p>Summary</p> <p>Tackling both personal and public inertia on organ donation is important for any community oriented kidney donation campaign.</p

    The Coxiella burnetii Dot/Icm System Delivers a Unique Repertoire of Type IV Effectors into Host Cells and Is Required for Intracellular Replication

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    Coxiella burnetii, the causative agent of human Q fever, is an intracellular pathogen that replicates in an acidified vacuole derived from the host lysosomal network. This pathogen encodes a Dot/Icm type IV secretion system that delivers bacterial proteins called effectors to the host cytosol. To identify new effector proteins, the functionally analogous Legionella pneumophila Dot/Icm system was used in a genetic screen to identify fragments of C. burnetii genomic DNA that when fused to an adenylate cyclase reporter were capable of directing Dot/Icm-dependent translocation of the fusion protein into mammalian host cells. This screen identified Dot/Icm effectors that were proteins unique to C. burnetii, having no overall sequence homology with L. pneumophila Dot/Icm effectors. A comparison of C. burnetii genome sequences from different isolates revealed diversity in the size and distribution of the genes encoding many of these effectors. Studies examining the localization and function of effectors in eukaryotic cells provided evidence that several of these proteins have an affinity for specific host organelles and can disrupt cellular functions. The identification of a transposon insertion mutation that disrupts the dot/icm locus was used to validate that this apparatus was essential for translocation of effectors. Importantly, this C. burnetii Dot/Icm-deficient mutant was found to be defective for intracellular replication. Thus, these data indicate that C. burnetii encodes a unique subset of bacterial effector proteins translocated into host cells by the Dot/Icm apparatus, and that the cumulative activities exerted by these effectors enables C. burnetii to successfully establish a niche inside mammalian cells that supports intracellular replication

    RANK, RANKL and osteoprotegerin in bone biology and disease

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    Upon the discovery of RANK, RANKL and OPG in the late 1990s, their importance in the maintenance of the skeletal structure and their dramatic role in bone disease were largely unexpected. In recent years the understanding of these proteins, in particular their regulation, has greatly increased. This review aims to bring the interested reader up to date with the latest news and views on the mechanisms controlling bone resorption in normal and pathological conditions

    Structural insight into the membrane targeting domain of the Legionella deAMPylase SidD

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    AMPylation, the post-translational modification with adenosine monophosphate (AMP), is catalyzed by effector proteins from a variety of pathogens. Legionella pneumophila is thus far the only known pathogen that, in addition to encoding an AMPylase (SidM/DrrA), also encodes a deAMPylase, called SidD, that reverses SidM-mediated AMPylation of the vesicle transport GTPase Rab1. DeAMPylation is catalyzed by the N-terminal phosphatase-like domain of SidD. Here, we determined the crystal structure of full length SidD including the uncharacterized C-terminal domain (CTD). A flexible loop rich in aromatic residues within the CTD was required to target SidD to model membranes in vitro and to the Golgi apparatus within mammalian cells. Deletion of the loop (??loop) or substitution of its aromatic phenylalanine residues rendered SidD cytosolic, showing that the hydrophobic loop is the primary membrane-targeting determinant of SidD. Notably, deletion of the two terminal alpha helices resulted in a CTD variant incapable of discriminating between membranes of different composition. Moreover, a L. pneumophila strain producing SidD??loop phenocopied a L. pneumophila ??sidD strain during growth in mouse macrophages and displayed prolonged co-localization of AMPylated Rab1 with LCVs, thus revealing that membrane targeting of SidD via its CTD is a critical prerequisite for its ability to catalyze Rab1 deAMPylation during L. pneumophila infection

    IPCC reasons for concern regarding climate change risks

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    The reasons for concern framework communicates scientific understanding about risks in relation to varying levels of climate change. The framework, now a cornerstone of the IPCC assessments, aggregates global risks into five categories as a function of global mean temperature change. We review the framework's conceptual basis and the risk judgments made in the most recent IPCC report, confirming those judgments in most cases in the light of more recent literature and identifying their limitations. We point to extensions of the framework that offer complementary climate change metrics to global mean temperature change and better account for possible changes in social and ecological system vulnerability. Further research should systematically evaluate risks under alternative scenarios of future climatic and societal conditions

    Reducing depression in older home care clients: design of a prospective study of a nurse-led interprofessional mental health promotion intervention

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    Abstract Background Very little research has been conducted in the area of depression among older home care clients using personal support services. These older adults are particularly vulnerable to depression because of decreased cognition, comorbid chronic conditions, functional limitations, lack of social support, and reduced access to health services. To date, research has focused on collaborative, nurse-led depression care programs among older adults in primary care settings. Optimal management of depression among older home care clients is not currently known. The objective of this study is to evaluate the feasibility, acceptability and effectiveness of a 6-month nurse-led, interprofessional mental health promotion intervention aimed at older home care clients with depressive symptoms using personal support services. Methods/Design This one-group pre-test post-test study aims to recruit a total of 250 long-stay (> 60 days) home care clients, 70 years or older, with depressive symptoms who are receiving personal support services through a home care program in Ontario, Canada. The nurse-led intervention is a multi-faceted 6-month program led by a Registered Nurse that involves regular home visits, monthly case conferences, and evidence-based assessment and management of depression using an interprofessional approach. The primary outcome is the change in severity of depressive symptoms from baseline to 6 months using the Centre for Epidemiological Studies in Depression Scale. Secondary outcomes include changes in the prevalence of depressive symptoms and anxiety, health-related quality of life, cognitive function, and the rate and appropriateness of depression treatment from baseline to 12 months. Changes in the costs of use of health services will be assessed from a societal perspective. Descriptive and qualitative data will be collected to examine the feasibility and acceptability of the intervention and identify barriers and facilitators to implementation. Discussion Data collection began in May 2010 and is expected to be completed by July 2012. A collaborative nurse-led strategy may provide a feasible, acceptable and effective means for improving the health of older home care clients by improving the prevention, recognition, and management of depression in this vulnerable population. The challenges involved in designing a practical, transferable and sustainable nurse-led intervention in home care are also discussed. Trial Registration ClinicalTrials.gov: NCT0140792

    Biased-corrected richness estimates for the Amazonian tree flora

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    Amazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals, where aggregation increases with rarity. By averaging several methods to estimate total richness, we confirm that over 15,000 tree species are expected to occur in Amazonia. We also show that using ten times the number of plots would result in an increase to just ~50% of those 15,000 estimated species. To get a more complete sample of all tree species, rigorous field campaigns may be needed but the number of trees in Amazonia will remain an estimate for years to come

    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

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    This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The percentages of dispersal modes per plot are included as Supporting Information (Table S7, based on 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests in Amazonia). The dispersal modes assigned to these 5433 species and morphospecies are also included as Supporting Information (Table S8).Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types.Colombian institution Departamento Administrativo de Ciencia, Tecnología e Innovación COLCIENCIASFaculty of Sciences, Universidad de los Ande

    IFITM3 restricts the morbidity and mortality associated with influenza

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    The 2009 H1N1 influenza pandemic showed the speed with which a novel respiratory virus can spread and the ability of a generally mild infection to induce severe morbidity and mortality in a subset of the population. Recent in vitro studies show that the interferon-inducible transmembrane (IFITM) protein family members potently restrict the replication of multiple pathogenic viruses1, 2, 3, 4, 5, 6, 7. Both the magnitude and breadth of the IFITM proteins’ in vitro effects suggest that they are critical for intrinsic resistance to such viruses, including influenza viruses. Using a knockout mouse model8, we now test this hypothesis directly and find that IFITM3 is essential for defending the host against influenza A virus in vivo. Mice lacking Ifitm3 display fulminant viral pneumonia when challenged with a normally low-pathogenicity influenza virus, mirroring the destruction inflicted by the highly pathogenic 1918 ‘Spanish’ influenza9, 10. Similar increased viral replication is seen in vitro, with protection rescued by the re-introduction of Ifitm3. To test the role of IFITM3 in human influenza virus infection, we assessed the IFITM3 alleles of individuals hospitalized with seasonal or pandemic influenza H1N1/09 viruses. We find that a statistically significant number of hospitalized subjects show enrichment for a minor IFITM3 allele (SNP rs12252-C) that alters a splice acceptor site, and functional assays show the minor CC genotype IFITM3 has reduced influenza virus restriction in vitro. Together these data reveal that the action of a single intrinsic immune effector, IFITM3, profoundly alters the course of influenza virus infection in mouse and human
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