4,211 research outputs found

    The Relationship Between Mucosal Microbiota, Colitis, and Systemic Inflammation in Chronic Granulomatous Disorder

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    PURPOSE: Chronic granulomatous disorder (CGD) is a primary immunodeficiency which is frequently complicated by inflammatory colitis and is associated with systemic inflammation. Herein, we aimed to investigate the role of the microbiome in the pathogenesis of colitis and systemic inflammation. METHODS: We performed 16S rDNA sequencing on mucosal biopsy samples from each segment of 10 CGD patients’ colons and conducted compositional and functional pathway prediction analyses. RESULTS: The microbiota in samples from colitis patients demonstrated reduced taxonomic alpha-diversity compared to unaffected patients, even in apparently normal bowel segments. Functional pathway richness was similar between the colitic and non-colitic mucosa, although metabolic pathways involved in butyrate biosynthesis or utilization were enriched in patients with colitis and correlated positively with fecal calprotectin levels. One patient with very severe colitis was dominated by Enterococcus spp., while among other patients Bacteroides spp. abundance correlated with colitis severity measured by fecal calprotectin and an endoscopic severity score. In contrast, Blautia abundance is associated with low severity scores and mucosal health. Several taxa and functional pathways correlated with concentrations of inflammatory cytokines in blood but not with colitis severity. Notably, dividing patients into “high” and “low” systemic inflammation groups demonstrated clearer separation than on the basis of colitis status in beta-diversity analyses. CONCLUSION: The microbiome is abnormal in CGD-associated colitis and altered functional characteristics probably contribute to pathogenesis. Furthermore, the relationship between the mucosal microbiome and systemic inflammation, independent of colitis status, implies that the microbiome in CGD can influence the inflammatory phenotype of the condition

    Narrowing the Range of Future Climate Projections Using Historical Observations of Atmospheric CO2

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    This is the final version. Available from American Meteorological Society via the DOI in this recordUncertainty in the behavior of the carbon cycle is important in driving the range in future projected climate change. Previous comparisons of model responses with historical CO2 observations have suggested a strong constraint on simulated projections that could narrow the range considered plausible. This study uses a new 57-member perturbed parameter ensemble of variants of an Earth system model for three future scenarios, which 1) explores a wider range of potential climate responses than before and 2) includes the impact of past uncertainty in carbon emissions on simulated trends. These two factors represent a more complete exploration of uncertainty, although they lead to a weaker constraint on the range of future CO2 concentrations as compared to earlier studies. Nevertheless, CO2 observations are shown to be effective at narrowing the distribution, excluding 30 of 57 simulations as inconsistent with historical CO2 changes. The perturbed model variants excluded are mainly at the high end of the future projected CO2 changes, with only 8 of the 26 variants projecting RCP8.5 2100 concentrations in excess of 1100 ppm retained. Interestingly, a minority of the high-end variants were able to capture historical CO2 trends, with the large-magnitude response emerging later in the century (owing to high climate sensitivities, strong carbon feedbacks, or both). Comparison with observed CO2 is effective at narrowing both the range and distribution of projections out to the mid-twenty-first century for all scenarios and to 2100 for a scenario with low emissions.This work was supported by the Joint U.K. DECC/DEFRA Met Office Hadley Centre Climate Programme (GA01101). Chris Jones’s contribution was supported by the CRESCENDO project under the European Union's Horizon 2020 research and innovation programme, Grant Agreement 641816. Jo House was supported by a Leverhulme Early Career Fellowship and EU FP7 Project LUC4C (603542). Stephen Sitch was supported by the EU FP7 through Project LUC4C (GA603542)

    Towards quantifying uncertainty in predictions of Amazon 'dieback'.

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    This is the final version of the article. It first appeared from The Royal Society via http://dx.doi.org/10.1098/rstb.2007.0028Simulations with the Hadley Centre general circulation model (HadCM3), including carbon cycle model and forced by a 'business-as-usual' emissions scenario, predict a rapid loss of Amazonian rainforest from the middle of this century onwards. The robustness of this projection to both uncertainty in physical climate drivers and the formulation of the land surface scheme is investigated. We analyse how the modelled vegetation cover in Amazonia responds to (i) uncertainty in the parameters specified in the atmosphere component of HadCM3 and their associated influence on predicted surface climate. We then enhance the land surface description and (ii) implement a multilayer canopy light interception model and compare with the simple 'big-leaf' approach used in the original simulations. Finally, (iii) we investigate the effect of changing the method of simulating vegetation dynamics from an area-based model (TRIFFID) to a more complex size- and age-structured approximation of an individual-based model (ecosystem demography). We find that the loss of Amazonian rainforest is robust across the climate uncertainty explored by perturbed physics simulations covering a wide range of global climate sensitivity. The introduction of the refined light interception model leads to an increase in simulated gross plant carbon uptake for the present day, but, with altered respiration, the net effect is a decrease in net primary productivity. However, this does not significantly affect the carbon loss from vegetation and soil as a consequence of future simulated depletion in soil moisture; the Amazon forest is still lost. The introduction of the more sophisticated dynamic vegetation model reduces but does not halt the rate of forest dieback. The potential for human-induced climate change to trigger the loss of Amazon rainforest appears robust within the context of the uncertainties explored in this paper. Some further uncertainties should be explored, particularly with respect to the representation of rooting depth

    Untargeted metagenomics protocol for the diagnosis of infection from CSF and tissue from sterile sites

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    Metagenomic next-generation sequencing (mNGS) is an untargeted technique capable of detecting all microbial nucleic acid within a sample. This protocol outlines our wet laboratory method for mNGS of cerebrospinal fluid (CSF) specimens and tissues from sterile sites. We use this method routinely in our clinical service, processing 178 specimens over the past 2.5 years in a laboratory that adheres to ISO:15189 standards. We have successfully used this protocol to diagnose multiple cases of encephalitis and hepatitis

    Disruption of VGLUT1 in cholinergic medial habenula projections increases nicotine self-administration

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    Cholinergic projections from the medial habenula (MHb) to the interpeduncular nucleus (IPN) have been studied for their complex contributions to nicotine addiction and have been implicated in nicotine reinforcement, aversion, and withdrawal. While it has been established that MHb cholinergic projections co-release glutamate, no direct evidence has demonstrated a role for this glutamate projection in nicotine consumption. In the present study, a novel floxed Slc17a7 (VGLUT1) mouse was generated and used to create conditional knockout (cKO) mice that lack VGLUT1 in MHb cholinergic neurons. Loss of Slc17a7 expression in ventral MHb cholinergic neurons was validated using fluorescent in situ hybridization, and immunohistochemistry was used to demonstrate a corresponding reduction of VGLUT1 protein in cholinergic terminals in the IPN. We also used optogenetics-assisted electrophysiology to evoke excitatory post-synaptic currents in IPN and observed a reduction of glutamatergic currents in the cKO, supporting the functional disruption of VGLUT1 in MHb to IPN synapses. cKO mice exhibited no gross phenotypic abnormalities and displayed normal thigmotaxis and locomotor behavior in the open-field assay. When trained to lever press for food, there was no difference between control and cKO. However, when tested in a nicotine self-administration procedure we found that the loss of VGLUT1-mediated glutamate co-release led to increased responding for nicotine. These findings indicate that glutamate co-release from ventral MHb cholinergic neurons opposes nicotine self-administration, and provide additional support for targeting this synapse to develop potential treatments for nicotine addiction

    Representation of Women in Stroke Clinical Trials: A Review of 281 Trials Involving More Than 500,000 Participants

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    Background and ObjectivesWomen have been underrepresented in cardiovascular disease clinical trials but there is less certainty over the level of disparity specifically in stroke. We examined the participation of women in trials according to stroke prevalence in the population.MethodsPublished randomized controlled trials with ≄100 participants enrolled between 1990 and 2020 were identified from ClinicalTrials.gov. To quantify sex disparities in enrollment, we calculated the participation to prevalence ratio (PPR), defined as the percentage of women participating in a trial vs the prevalence of women in the disease population.ResultsThere were 281 stroke trials eligible for analyses with a total of 588,887 participants, of whom 37.4% were women. Overall, women were represented at a lower proportion relative to their prevalence in the underlying population (mean PPR 0.84; 95% confidence interval [CI] 0.81-0.87). The greatest differences were observed in trials of intracerebral hemorrhage (PPR 0.73; 95% CI 0.71-0.74), trials with a mean age of participants <70 years (PPR 0.81; 95% CI 0.78-0.84), nonacute interventions (PPR 0.80; 95% CI 0.76-0.84), and rehabilitation trials (PPR 0.77; 95% CI 0.71-0.83). These findings did not significantly change over the period from 1990 to 2020 (p for trend = 0.201).DiscussionWomen are disproportionately underrepresented in stroke trials relative to the burden of disease in the population. Clear guidance and effective implementation strategies are required to improve the inclusion of women and thus broader knowledge of the impact of interventions in clinical trials

    Mother Knows Best: Dominant Females Determine Offspring Dispersal in Red Foxes (Vulpes vulpes)

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    Background: Relatedness between group members is central to understanding the causes of animal dispersal. In many group-living mammals this can be complicated as extra-pair copulations result in offspring having varying levels of relatedness to the dominant animals, leading to a potential conflict between male and female dominants over offspring dispersal strategies. To avoid resource competition and inbreeding, dominant males might be expected to evict unrelated males and related females, whereas the reverse strategy would be expected for dominant females. Methodology/Principal Findings: We used microsatellites and long-term data from an urban fox (Vulpes vulpes) population to compare dispersal strategies between offspring with intra- and extra-group fathers and mothers of differing social status in red foxes. Relatedness to the dominant male had no effect on dispersal in offspring of either sex, whereas there was a strong effect of relatedness to resident females on offspring dispersal independent of population density. Males with dominant mothers dispersed significantly more often than males with subordinate mothers, whereas dispersing females were significantly more likely to have subordinate mothers compared to philopatric females. Conclusions/Significance: This is the first study to demonstrate that relatedness to resident females is important in juvenile dispersal in group-living mammals. Male dispersal may be driven by inbreeding avoidance, whereas female dispersal appears to be influenced by the fitness advantages associated with residing with the same-sex dominant parent. Selection pressure for paternal influence on offspring dispersal is low due to the limited costs associated with retaining unrelated males and the need for alternative inbreeding avoidance mechanisms between the dominant male and his female offspring. These findings have important implications for the evolution of dispersal and group living in social mammals, and our understanding of a key biological process.peerReviewe

    Comparison of new forms of creatine in raising plasma creatine levels

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    <p>Abstract</p> <p>Background</p> <p>Previous research has shown that plasma creatine levels are influenced by extracellular concentrations of insulin and glucose as well as by the intracellular creatine concentration. However, the form of creatine administered does not appear to have any effect although specific data on this is lacking. This study examined whether the administration of three different forms of creatine had different effects on plasma creatine concentrations and pharmacokinetics.</p> <p>Methods</p> <p>Six healthy subjects (three female and three male subjects) participated in the study. Each subject was assigned to ingest a single dose of isomolar amounts of creatine (4.4 g) in the form of creatine monohydrate (CrM), tri-creatine citrate (CrC), or creatine pyruvate (CrPyr) using a balanced cross-over design. Plasma concentration curves, determined over eight hours after ingestion, were subject to pharmacokinetic analysis and primary derived data were analyzed by repeated measures ANOVA.</p> <p>Results</p> <p>Mean peak concentrations and area under the curve (AUC) were significantly higher with CrPyr (17 and 14%, respectively) in comparison to CrM and CrC. Mean peak concentration and AUC were not significantly different between CrM and CrC. Despite the higher peak concentration with CrPyr there was no difference between the estimated velocity constants of absorption (ka) or elimination (kel) between the three treatments. There was no effect of treatment with CrPyr on the plasma pyruvate concentration.</p> <p>Conclusion</p> <p>The findings suggest that different forms of creatine result in slightly altered kinetics of plasma creatine absorption following ingestion of isomolar (with respect to creatine) doses of CrM, CrC and CrPyr although differences in ka could not be detected due to the small number of blood samples taken during the absorption phase. Characteristically this resulted in higher plasma concentrations of creatine with CrPyr. Differences in bioavailability are thought to be unlikely since absorption of CrM is already close to 100%. The small differences in kinetics are unlikely to have any effect on muscle creatine elevation during periods of creatine loading.</p

    The design-by-adaptation approach to universal access: learning from videogame technology

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    This paper proposes an alternative approach to the design of universally accessible interfaces to that provided by formal design frameworks applied ab initio to the development of new software. This approach, design-byadaptation, involves the transfer of interface technology and/or design principles from one application domain to another, in situations where the recipient domain is similar to the host domain in terms of modelled systems, tasks and users. Using the example of interaction in 3D virtual environments, the paper explores how principles underlying the design of videogame interfaces may be applied to a broad family of visualization and analysis software which handles geographical data (virtual geographic environments, or VGEs). One of the motivations behind the current study is that VGE technology lags some way behind videogame technology in the modelling of 3D environments, and has a less-developed track record in providing the variety of interaction methods needed to undertake varied tasks in 3D virtual worlds by users with varied levels of experience. The current analysis extracted a set of interaction principles from videogames which were used to devise a set of 3D task interfaces that have been implemented in a prototype VGE for formal evaluation

    Detection of chromosome aberrations in metaphase and interphase tumor cells by in situ hybridization using chromosome-specific library probes

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    Chromosome aberrations in two glioma cell lines were analyzed using biotinylated DNA library probes that specifically decorate chromosomes 1, 4, 7, 18 and 22 from pter to qter. Numerical changes, deletions and rearrangements of these chromosomes were radily visualized in metaphase spreads, as well as in early prophase and interphase nuclei. Complete chromosomes, deleted chromosomes and segments of translocated chromosomes were rapidly delineated in very complex karyotypes. Simultaneous hybridizations with additional subregional probes were used to further define aberrant chromosomes. Digital image analysis was used to quantitate the total complement of specific chromosomal DNAs in individual metaphase and interphase cells of each cell line. In spite of the fact that both glioma lines have been passaged in vitro for many years, an under-representation of chromosome 22 and an over-representation of chromosome 7 (specifically 7p) were observed. These observations agree with previous studies on gliomas. In addition, sequences of chromosome 4 were also found to be under-represented, especially in TC 593. These analyses indicate the power of these methods for pinpointing chromosome segments that are altered in specific types of tumors
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