12 research outputs found

    Intestinal Microbiota Shifts towards Elevated Commensal Escherichia coli Loads Abrogate Colonization Resistance against Campylobacter jejuni in Mice

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    Background: The zoonotic pathogen Campylobacter jejuni is a leading cause of bacterial foodborne enterocolitis in humans worldwide. The understanding of immunopathology underlying human campylobacteriosis is hampered by the fact that mice display strong colonization resistance against the pathogen due to their host specific gut microbiota composition. Methodology/Principal Findings: Since the microbiota composition changes significantly during intestinal inflammation we dissected factors contributing to colonization resistance against C. jejuni in murine ileitis, colitis and in infant mice. In contrast to healthy animals C. jejuni could stably colonize mice suffering from intestinal inflammation. Strikingly, in mice with Toxoplasma gondii-induced acute ileitis, C. jejuni disseminated to mesenteric lymphnodes, spleen, liver, kidney, and blood. In infant mice C. jejuni infection induced enterocolitis. Mice suffering from intestinal inflammation and C. jejuni susceptible infant mice displayed characteristical microbiota shifts dominated by increased numbers of commensal Escherichia coli. To further dissect the pivotal role of those distinct microbiota shifts in abrogating colonization resistance, we investigated C. jejuni infection in healthy adult mice in which the microbiota was artificially modified by feeding live commensal E. coli. Strikingly, in animals harboring supra-physiological intestinal E. coli loads, colonization resistance was significantly diminished and C. jejuni infection induced enterocolitis mimicking key features of human campylobacteriosis. Conclusion/Significance: Murine colonization resistance against C. jejuni is abrogated by changes in the microbiot

    Engaging Teenagers with Science Through Comics

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    It is increasingly important for all citizens, and especially youth, to understand how viruses impact our health, communities and environment. Particularly for youth less interested in traditional science learning materials, comics may provide a way to engage teenagers with scientific information about viruses. We compared the impacts of different formats of educational materials on teenagers’ knowledge of, attitudes toward, and engagement with information about viruses. High school students (N = 873) were randomly assigned to read either a high quality comic or essay about viruses. Latent class analysis grouped youth into one of four categories that captured a range from low to high science identity. We compared material type (comic/essay) and science identity (low to high) on knowledge, attitudes and engagement. There were no comic/essay differences on knowledge, nor on attitudes about the importance of or interest in viruses. Across all levels of science identity, however, teenagers in the comic group were significantly more likely to want to read more similar materials than teenagers in the essay group, thus indicating more engagement. This effect was more pronounced among youth in the low compared to the higher identity categories. Our findings support the notion that comics can appeal to a wider audience of learners than traditional essays while still resulting in similar knowledge scores. This suggests that comics can be an important and effective tool to engage a broad spectrum of youth with science learning materials

    Retinal vascular image analysis as a potential screening tool for cerebrovascular disease: a rationale based on homology between cerebral and retinal microvasculatures

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    The retinal and cerebral microvasculatures share many morphological and physiological properties. Assessment of the cerebral microvasculature requires highly specialized and expensive techniques. The potential for using non-invasive clinical assessment of the retinal microvasculature as a marker of the state of the cerebrovasculature offers clear advantages, owing to the ease with which the retinal vasculature can be directly visualized in vivo and photographed due to its essential two-dimensional nature. The use of retinal digital image analysis is becoming increasingly common, and offers new techniques to analyse different aspects of retinal vascular topography, including retinal vascular widths, geometrical attributes at vessel bifurcations and vessel tracking. Being predominantly automated and objective, these techniques offer an exciting opportunity to study the potential to identify retinal microvascular abnormalities as markers of cerebrovascular pathology. In this review, we describe the anatomical and physiological homology between the retinal and cerebral microvasculatures. We review the evidence that retinal microvascular changes occur in cerebrovascular disease and review current retinal image analysis tools that may allow us to use different aspects of the retinal microvasculature as potential markers for the state of the cerebral microvasculature
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