423 research outputs found

    The intestinal immunoendocrine axis:novel cross-talk between enteroendocrine cells and the immune system during infection and inflammatory disease

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    The intestinal epithelium represents one of our most important interfaces with the external environment. It must remain tightly balanced to allow nutrient absorption, but maintain barrier function and immune homoeostasis, a failure of which results in chronic infection or debilitating inflammatory bowel disease (IBD). The intestinal epithelium mainly consists of absorptive enterocytes and secretory goblet and Paneth cells and has recently come to light as being an essential modulator of immunity as opposed to a simple passive barrier. Each epithelial sub-type can produce specific immune modulating factors, driving innate immunity to pathogens as well as preventing autoimmunity. The enteroendocrine cells comprise just 1% of this epithelium, but collectively form the bodies' largest endocrine system. The mechanisms of enteroendocrine cell peptide secretion during feeding, metabolism and nutrient absorption are well studied; but their potential interactions with the enriched numbers of surrounding immune cells remain largely unexplored. This review focuses on alterations in enteroendocrine cell number and peptide secretion during inflammation and disease, highlighting the few in depth studies which have attempted to dissect the immune driven mechanisms that drive these phenomena. Moreover, the emerging potential of enteroendocrine cells acting as innate sensors of intestinal perturbation and secreting peptides to directly orchestrate immune cell function will be proposed. In summary, the data generated from these studies have begun to unravel a complex cross-talk between immune and enteroendocrine cells, highlighting the emerging immunoendocrine axis as a potential target for therapeutic strategies for infections and inflammatory disorders of the intestine

    Adaptive immunity alters distinct host feeding pathways during nematode induced inflammation, a novel mechanism in parasite expulsion

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    Gastrointestinal infection is often associated with hypophagia and weight loss; however, the precise mechanisms governing these responses remain poorly defined. Furthermore, the possibility that alterations in feeding during infection may be beneficial to the host requires further study. We used the nematode Trichinella spiralis, which transiently inhabits the small intestine before migrating to skeletal muscle, as a biphasic model of infection to determine the cellular and molecular pathways controlling feeding during enteric and peripheral inflammation. Through the infection of genetically modified mice lacking cholecystokinin, Tumor necrosis factor α receptors and T and B-cells, we observed a biphasic hypophagic response to infection resulting from two separate immune-driven mechanisms. The enteroendocrine I-cell derived hormone cholecystokinin is an essential mediator of initial hypophagia and is induced by CD4+ T-cells during enteritis. In contrast, the second hypophagic response is extra-intestinal and due to the anorectic effects of TNFα during peripheral infection of the muscle. Moreover, via maintaining naive levels of the adipose secreted hormone leptin throughout infection we demonstrate a novel feedback loop in the immunoendocrine axis. Immune driven I-cell hyperplasia and resultant weight loss leads to a reduction in the inflammatory adipokine leptin, which in turn heightens protective immunity during infection. These results characterize specific immune mediated mechanisms which reduce feeding during intestinal or peripheral inflammation. Importantly, the molecular mediators of each phase are entirely separate. The data also introduce the first evidence that I-cell hyperplasia is an adaptively driven immune response that directly impinges on the outcome to infection

    Molecular neurochemistry of the lanthanides

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    Lanthanides, once termed rare‐earth elements, are not as sparce in the environment as their traditional name suggests. Mean litospheric concentrations are in fact comparable to the physiologically fundamental elements such as iodine, cobalt, and selenium. Recent advances in medical technology have resulted in accumulation of lanthanides presenting potential exposure to both our central and peripheral nervous systems. Extensive and detailed studies on these peculiar active metals in the context of their influence on neural functions are therefore urgently required. Almost all neurochemical effects of trivalent lanthanide ions appear to result from the similarity of their radii to the key signaling ion calcium. Lanthanides, especially La3+ and Gd3+ block different types of calcium, potassium, and sodium channels in human and animal neurons, regulate neurotransmitter turnover and release, as well as synaptic activity. Lanthanides also act as modulators of several ionotropic receptors, e.g., GABA, NMDA, and kainate and can also affect numerous signaling mechanisms including NF‐κB and apoptotic‐related endoplasmic reticulum IRE1‐XBP1, PERK, and ATF6 pathways. Several lanthanide ions may cause oxidative neuronal injuries and functional impairment by promoting reactive oxygen species production. However, cerium and yttrium oxides have some unique and promising neuroprotective properties, being able to decrease free radical cell injury and even alleviate motor impairment and cognitive function in animal models of multiple sclerosis and mild traumatic brain damage, respectively. In conclusion, lanthanides affect various neurophysiological processes, altering a large spectrum of brain functions. Thus, a deeper understanding of their potential mechanistic roles during disease and as therapeutic agents requires urgent elucidation

    Scanwave: A New Approach to Enhancing Spectral Data on a Tandem Quadrupole Mass Spectrometer

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    A new type of mass analyzer is described, which allows low-resolution axial ion ejection to be obtained from a traveling wave based, stacked ring collision cell. Linking this ejection temporally with the scanning of the second quadrupole of a tandem quadrupole mass spectrometer provides an improvement in sampling duty cycle, which results in significant signal intensity improvements for scanning acquisitions such as product ion spectra. A near 100% storage efficiency is enabled by a split cell design, which allows ion fragmentation and accumulation to be performed in one section of the collision cell whilst previously accumulated ions are simultaneously ejected from the rear of the cell. These characteristics combine to give an m/z-dependent signal gain of 7–20× over a conventional scanning quadrupole for a 1000 Th scan. The ability to swap very rapidly from a non-enhanced mode of operation to an enhanced mode whilst retaining the existing sensitivity, speed, and functionality of a conventional tandem quadrupole mass spectrometer is also described

    Family Business CEO Succession: Examining Personal Retirement Expectations

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    Retirement well-being expectations of incumbent family owned business CEOs is a critical precursor to successful succession events. The significant antecedents to retirement well-being expectation are family relationships, wealth management and transfer, leadership succession and development, and continuity and viability of the firm. Using data from a survey of 256 family firm CEOs we demonstrate those relationships and show a very strong connection between retirement well-being expectation and firm performance. Study results further our premise that antecedents to retirement well-being expectation are indirectly tied to the overall health and performance of the family firm

    Intestinal dendritic cells specialize to activate transforming growth factor-β and induce Foxp3+ regulatory T cells via integrin αvβ8

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    BACKGROUND & AIMS: The intestinal immune system is tightly regulated to prevent responses against the many nonpathogenic antigens in the gut. Transforming growth factor (TGF)-β is a cytokine that maintains intestinal homeostasis, in part by inducing Foxp3(+) regulatory T cells (Tregs) that suppress immune responses. TGF-β is expressed at high levels in the gastrointestinal tract as a latent complex that must be activated. However, the pathways that control TGF-β activation in the intestine are poorly defined. We investigated the cellular and molecular pathways that control activation of TGF-β and induction of Foxp3(+) Tregs in the intestines of mice to maintain immune homeostasis. METHODS: Subsets of intestinal dendritic cells (DCs) were examined for their capacity to activate TGF-β and induce Foxp3(+) Tregs in vitro. Mice were fed oral antigen, and induction of Foxp3(+) Tregs was measured. RESULTS: A tolerogenic subset of intestinal DCs that express CD103 were specialized to activate latent TGF-β, and induced Foxp3(+) Tregs independently of the vitamin A metabolite retinoic acid. The integrin αvβ8, which activates TGF-β, was significantly up-regulated on CD103(+) intestinal DCs. DCs that lack expression of integrin αvβ8 had reduced ability to activate latent TGF-β and induce Foxp3(+) Tregs in vitro and in vivo. CONCLUSIONS: CD103(+) intestinal DCs promote a tolerogenic environment in the intestines of mice via integrin αvβ8-mediated activation of TGF-β

    Long-term treatment with haloperidol affects neuropeptide S and NPSR mRNA levels in the rat brain

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    OBJECTIVE: The brainstem-derived neuropeptide S (NPS) has a multidirectional regulatory activity, especially as a potent anxiolytic factor. Accumulating data suggests that neuroleptics affect peptidergic signalling in various brain structures. However, there is no information regarding the influence of haloperidol on NPS and NPS receptor (NPSR) expression. METHODS: We assessed NPS and NPSR mRNA levels in brains of rats treated with haloperidol using quantitative real-time polymerase chain reaction. RESULTS: Chronic haloperidol treatment (4 weeks) led to a striking upregulation of NPS and NPSR expression in the rat brainstem. Conversely, the NPSR mRNA expression was decreased in the hippocampus and striatum. CONCLUSIONS: This stark increase of NPS in response to haloperidol treatment supports the hypothesis that this neuropeptide is involved in the dopamine-dependent anxiolytic actions of neuroleptics and possibly also in the pathophysiology of mental disorders. Furthermore, our findings underline the complex nature of potential interactions between dopamine receptors and brain peptidergic pathways, which has potential clinical applications

    Infection rates of the LifeSite hemodialysis access system

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    Improved early detection of ovarian cancer using longitudinal multimarker models

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    © The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Background: Ovarian cancer has a poor survival rate due to late diagnosis and improved methods are needed for its early detection. Our primary objective was to identify and incorporate additional biomarkers into longitudinal models to improve on the performance of CA125 as a first-line screening test for ovarian cancer. Methods: This case–control study nested within UKCTOCS used 490 serial serum samples from 49 women later diagnosed with ovarian cancer and 31 control women who were cancer-free. Proteomics-based biomarker discovery was carried out using pooled samples and selected candidates, including those from the literature, assayed in all serial samples. Multimarker longitudinal models were derived and tested against CA125 for early detection of ovarian cancer. Results: The best performing models, incorporating CA125, HE4, CHI3L1, PEBP4 and/or AGR2, provided 85.7% sensitivity at 95.4% specificity up to 1 year before diagnosis, significantly improving on CA125 alone. For Type II cases (mostly high-grade serous), models achieved 95.5% sensitivity at 95.4% specificity. Predictive values were elevated earlier than CA125, showing the potential of models to improve lead time. Conclusions: We have identified candidate biomarkers and tested longitudinal multimarker models that significantly improve on CA125 for early detection of ovarian cancer. These models now warrant independent validation.Peer reviewe
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