249 research outputs found

    Women and Alport syndrome

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    X-linked Alport syndrome (XLAS) is caused by mutations in type IV collagen causing sensorineural hearing loss, eye abnormalities, and progressive kidney dysfunction that results in near universal end-stage renal disease (ESRD) and the need for kidney transplantation in affected males. Until recent decades, the disease burden in heterozygous “carrier” females was largely minimized or ignored. Heterozygous females have widely variable disease outcomes, with some affected females exhibiting normal urinalysis and kidney function, while others develop ESRD and deafness. While the determinants of disease severity in females with XLAS are uncertain, skewing of X-chromosome inactivation has recently been found to play a role. This review will explore the natural history of heterozygous XLAS females, the determinants of disease severity, and the utility of using XLAS females as kidney donors

    Segmental infantile hemangioma and concomitant hypertension in three African American neonates

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    We present three African American infants with segmental, ulcerated infantile hemangiomas and concomitant, persistent hypertension. When treated with beta-blocker therapy, the hemangiomas decreased in size and the ulcerations resolved, but there was no impact on the elevated blood pressure in one of our patients. We failed to identify any associations between infantile hemangioma and hypertension in the literature

    Acquisition of Ca2+ and HCO3−/CO32− for shell formation in embryos of the common pond snail Lymnaea stagnalis

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    Embryos of the freshwater common pond snail Lymnaea stagnalis develop to hatch within 10 days under control conditions (22°C, Miami-Dade tap water) and this development is impaired by removal of ambient calcium. In contrast, embryos did not exhibit dependence upon an ambient HCO3−/CO32− source, developing and hatching in HCO3−/CO32−-free water at rates comparable to controls. Post-metamorphic, shell-laying embryos exhibited a significant saturation-type calcium uptake as a function of increasing ambient calcium concentration. However, changes in ambient bicarbonate concentration did not influence calcium or apparent titratable alkalinity uptake. There was a distinct shift from no significant flux in pre-metamorphic embryos to net uptake of calcium in post-metamorphic stages as indicated by an increased uptake from the micro-environment surrounding the egg mass and increased net uptake in 24-h, whole egg mass flux measurements. Furthermore, HCO3−/CO32− acquisition as measured by titratable alkalinity flux is at least partially attributable to an endogenous carbonate source that is associated with acid extrusion. Thus, calcium requirements for embryonic shell formation are met via uptake but HCO3−/CO32−, which is also necessary for shell formation is acquired in part from endogenous sources with no detectable correlation to ambient HCO3−/CO32− availability

    Recommended Priorities for Research on Ecological Impacts of Ocean and Coastal Acidification in the U.S. Mid-Atlantic

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    The estuaries and continental shelf system of the United States Mid-Atlantic are subject to ocean acidification driven by atmospheric CO2, and coastal acidification caused by nearshore and land-sea interactions that include biological, chemical, and physical processes. These processes include freshwater and nutrient input from rivers and groundwater; tidally-driven outwelling of nutrients, inorganic carbon, alkalinity; high productivity and respiration; and hypoxia. Hence, these complex dynamic systems exhibit substantial daily, seasonal, and interannual variability that is not well captured by current acidification research on Mid-Atlantic organisms and ecosystems. We present recommendations for research priorities that target better understanding of the ecological impacts of acidification in the U. S. Mid-Atlantic region. Suggested priorities are: 1) Determining the impact of multiple stressors on our resource species as well as the magnitude of acidification; 2) Filling information gaps on major taxa and regionally important species in different life stages to improve understanding of their response to variable temporal scales and sources of acidification; 3) Improving experimental approaches to incorporate realistic environmental variability and gradients, include interactions with other environmental stressors, increase transferability to other systems or organisms, and evaluate community and ecosystem response; 4) Determining the capacity of important species to acclimate or adapt to changing ocean conditions; 5) Considering multi-disciplinary, ecosystem-level research that examines acidification impacts on biodiversity and biotic interactions; and 6) Connecting potential acidification-induced ecological impacts to ecosystem services and the economy. These recommendations, while developed for the Mid-Atlantic, can be applicable to other regions will help align research towards knowledge of potential larger-scale ecological and economic impacts

    Variants of a genomic island in Aeromonas salmonicida subsp. salmonicida link isolates with their geographical origins

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    Aeromonas salmonicida subsp. salmonicida is a fish pathogen. Analysis of its genomic characteristics is required to determine the worldwide distribution of the various populations of this bacterium. Genomic alignments between the 01-B526 pathogenic strain and the A449 reference strain have revealed a 51-kb chromosomal insertion in 01-B526. This insertion (AsaGEI1a) has been identified as a new genomic island (GEI) bearing prophage genes. PCR assays were used to detect this GEI in a collection of 139 A. salmonicida subsp. salmonicida isolates. Three forms of this GEI (AsaGEI1a, AsaGEI1b, AsaGEI2a) are now known based on this analysis and the sequencing of the genomes of seven additional isolates. A new prophage (prophage 3) associated with AsaGEI2a was also discovered. Each GEI appeared to be strongly associated with a specific geographic region. AsaGEI1a and AsaGEI2a were exclusively found in North American isolates, except for one European isolate bearing AsaGEI2a. The majority of the isolates bearing AsaGEI1b or no GEI were from Europe. Prophage 3 has also a particular geographic distribution and was found only in North American isolates. We demonstrated that A. salmonicida subsp. salmonicida possesses unsuspected elements of genomic heterogeneity that could be used as indicators to determine the geographic origins of isolates of this bacterium.Keywords : Bacteria, Genomics-functional genomics-comparative genomics; Furunculosis; Aeromonas salmonicida; Fish pathogen; Genomic island; Geographical distributio

    PreCam, a Precursor Observational Campaign for Calibration of the Dark Energy Survey

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    PreCam, a precursor observational campaign supporting the Dark Energy Survey (DES), is designed to produce a photometric and astrometric catalog of nearly a hundred thousand standard stars within the DES footprint, while the PreCam instrument also serves as a prototype testbed for the Dark Energy Camera (DECam)'s hardware and software. This catalog represents a potential 100-fold increase in Southern Hemisphere photometric standard stars, and therefore will be an important component in the calibration of the Dark Energy Survey. We provide details on the PreCam instrument's design, construction and testing, as well as results from a subset of the 51 nights of PreCam survey observations on the University of Michigan Department of Astronomy's Curtis-Schmidt telescope at Cerro Tololo Inter-American Observatory. We briefly describe the preliminary data processing pipeline that has been developed for PreCam data and the preliminary results of the instrument performance, as well as astrometry and photometry of a sample of stars previously included in other southern sky surveys.Comment: 21 pages, 15 figures, submitted to PAS

    Developing Consensus-Based Outcome Domains for Trials in Children and Adolescents With CKD: An International Delphi Survey

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    RATIONALE & OBJECTIVE: The inconsistency in outcomes reported and lack of patient-reported outcomes across trials in children with chronic kidney disease (CKD) limits shared decision making. As part of the Standardized Outcomes in Nephrology (SONG)-Kids initiative, we aimed to generate a consensus-based prioritized list of critically important outcomes to be reported in all trials in children with CKD. STUDY DESIGN: An online 2-round Delphi survey in English, French, and Hindi languages. SETTINGS & PARTICIPANTS: Patients (aged 8-21 years), caregivers/family, and health care professionals (HCPs) rated the importance of outcomes using a 9-point Likert scale (7-9 indicating critical importance) and completed a Best-Worst Scale. ANALYTICAL APPROACH: We assessed the absolute and relative importance of outcomes. Comments were analyzed thematically. RESULTS: 557 participants (72 [13%] patients, 132 [24%] caregivers, and 353 [63%] HCPs) from 48 countries completed round 1 and 312 (56%) participants (28 [40%] patients, 64 [46%] caregivers, and 220 [56%] HCPs) completed round 2. Five outcomes were common in the top 10 for each group: mortality, kidney function, life participation, blood pressure, and infection. Caregivers and HCPs rated cardiovascular disease higher than patients. Patients gave lower ratings to all outcomes compared with caregivers/HCPs except they rated life participation (round 2 mean difference, 0.1), academic performance (0.1), mobility (0.4), and ability to travel (0.4) higher than caregivers and rated ability to travel (0.4) higher than HCPs. We identified 3 themes: alleviating disease and treatment burden, focusing on the whole child, and resolving fluctuating and conflicting goals. LIMITATIONS: Most participants completed the survey in English. CONCLUSIONS: Mortality, life participation, kidney function, and blood pressure were consistently highly prioritized by patients, caregivers, and HCPs. Patients gave higher priority to some lifestyle-related outcomes compared with caregivers/HCPs. Establishing critically important outcomes for all trials in children with CKD may improve consistent reporting of survival, kidney health, and clinical and life impact outcomes that are meaningful for decision making

    Attraction and repulsion of mobile wild organisms to finfish and shellfish aquaculture: a review

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    Knowledge of aquaculture–environment interactions is essential for the development of a sustainable aquaculture industry and efficient marine spatial planning. The effects of fish and shellfish farming on sessile wild populations, particularly infauna, have been studied intensively. Mobile fauna, including crustaceans, fish, birds and marine mammals, also interact with aquaculture operations, but the interactions are more complex and these animals may be attracted to (attraction) or show an aversion to (repulsion) farm operations with various degrees of effects. This review outlines the main mechanisms and effects of attraction and repulsion of wild animals to/from marine finfish cage and bivalve aquaculture, with a focus on effects on fisheries-related species. Effects considered in this review include those related to the provision of physical structure (farm infrastructure acting as fish aggregating devices (FADs) or artificial reefs (ARs), the provision of food (e.g. farmed animals, waste feed and faeces, fouling organisms associated with farm structures) and some farm activities (e.g. boating, cleaning). The reviews show that the distribution of mobile organisms associated with farming structures varies over various spatial (vertical and horizontal) and temporal scales (season, feeding time, day/night period). Attraction/repulsion mechanisms have a variety of direct and indirect effects on wild organisms at the level of individuals and populations and may have implication for the management of fisheries species and the ecosystem in the context of marine spatial planning. This review revealed considerable uncertainties regarding the long-term and ecosystem-wide consequences of these interactions. The use of modelling may help better understand consequences, but long-term studies are necessary to better elucidate effects

    Fiber tractography bundle segmentation depends on scanner effects, vendor effects, acquisition resolution, diffusion sampling scheme, diffusion sensitization, and bundle segmentation workflow

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    When investigating connectivity and microstructure of white matter pathways of the brain using diffusion tractography bundle segmentation, it is important to understand potential confounds and sources of variation in the process. While cross-scanner and cross-protocol effects on diffusion microstructure measures are well described (in particular fractional anisotropy and mean diffusivity), it is unknown how potential sources of variation effect bundle segmentation results, which features of the bundle are most affected, where variability occurs, nor how these sources of variation depend upon the method used to reconstruct and segment bundles. In this study, we investigate six potential sources of variation, or confounds, for bundle segmentation: variation (1) across scan repeats, (2) across scanners, (3) across vendors (4) across acquisition resolution, (5) across diffusion schemes, and (6) across diffusion sensitization. We employ four different bundle segmentation workflows on two benchmark multi-subject cross-scanner and cross-protocol databases, and investigate reproducibility and biases in volume overlap, shape geometry features of fiber pathways, and microstructure features within the pathways. We find that the effects of acquisition protocol, in particular acquisition resolution, result in the lowest reproducibility of tractography and largest variation of features, followed by vendor-effects, scanner-effects, and finally diffusion scheme and b-value effects which had similar reproducibility as scan-rescan variation. However, confounds varied both across pathways and across segmentation workflows, with some bundle segmentation workflows more (or less) robust to sources of variation. Despite variability, bundle dissection is consistently able to recover the same location of pathways in the deep white matter, with variation at the gray matter/ white matter interface. Next, we show that differences due to the choice of bundle segmentation workflows are larger than any other studied confound, with low-to-moderate overlap of the same intended pathway when segmented using different methods. Finally, quantifying microstructure features within a pathway, we show that tractography adds variability over-and-above that which exists due to noise, scanner effects, and acquisition effects. Overall, these confounds need to be considered when harmonizing diffusion datasets, interpreting or combining data across sites, and when attempting to understand the successes and limitations of different methodologies in the design and development of new tractography or bundle segmentation methods
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