986 research outputs found

    Natural Killer Cells in Human Immunodeficiency Virus-1 Infection: Spotlight on the Impact of Human Cytomegalovirus

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    Human cytomegalovirus (HCMV) has been closely associated with the human race across evolutionary time. HCMV co-infection is nearly universal in human immunodeficiency virus-1 (HIV-1)-infected individuals and remains an important cofactor in HIV-1 disease progression even in the era of effective antiretroviral treatment. HCMV infection has been shown to have a broad and potent influence on the human immune system and has been linked with the discovery and characterization of adaptive natural killer (NK) cells. Distinct NK-cell subsets, predominately expressing the activating receptor NKG2C and the marker of terminal differentiation CD57, expand in response to HCMV. These NK-cell populations engaged in the long-lasting interaction with HCMV, in addition to characteristic but variable expression of surface receptors, exhibit reduced expression of signaling proteins and transcription factors expressed by canonical NK cells. Broad epigenetic modifications drive the emergence and persistence of HCMV-adapted NK cells that have distinct functional characteristics. NKG2C+ NK-cell expansions have been observed in HIV-1 infected patients and other acute and chronic viral infections being systematically associated with HCMV seropositivity. The latter is potentially an important confounding variable in studies focused on the cellular NK-cell receptor repertoire and functional capacity. Here, focusing on HIV-1 infection we review the evidence in favor of “adaptive” changes likely induced by HCMV co-infection in NK-cell subsets. We highlight a number of key questions and how insights into the adaptive behavior of NK cells will inform new strategies exploiting their unique properties in the fight against HIV-1

    Shared immunotherapeutic approaches in HIV and hepatitis B virus: combine and conquer

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    Purpose of review: The aim of this study was to identify similarities, differences and lessons to be shared from recent progress in HIV and hepatitis B virus (HBV) immunotherapeutic approaches. Recent findings: Immune dysregulation is a hallmark of both HIV and HBV infection, which have shared routes of transmission, with approximately 10% of HIV-positive patients worldwide being coinfected with HBV. Immune modulation therapies to orchestrate effective innate and adaptive immune responses are currently being sought as potential strategies towards a functional cure in both HIV and HBV infection. These are based on activating immunological mechanisms that would allow durable control by triggering innate immunity, reviving exhausted endogenous responses and/or generating new immune responses. Recent technological advances and increased appreciation of humoral responses in the control of HIV have generated renewed enthusiasm in the cure field. Summary: For both HIV and HBV infection, a primary consideration with immunomodulatory therapies continues to be a balance between generating highly effective immune responses and mitigating any significant toxicity. A large arsenal of new approaches and ongoing research offer the opportunity to define the pathways that underpin chronic infection and move closer to a functional cure

    Systemic inflammation and residual viraemia in HIV-positive adults on protease inhibitor monotherapy: a cross-sectional study.

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    Increased levels of markers of systemic inflammation have been associated with serious non-AIDS events even in patients on fully suppressive antiretroviral therapy. We explored residual viremia and systemic inflammation markers in patients effectively treated with ritonavir-boosted protease inhibitor monotherapy (PImono)

    Lipid Abnormalities and Cardiometabolic Risk in Patients with Overt and Subclinical Thyroid Disease

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    Dyslipidemia is a common finding in patients with thyroid disease, explained by the adverse effects of thyroid hormones in almost all steps of lipid metabolism. Not only overt but also subclinical hypo- and hyperthyroidism, through different mechanisms, are associated with lipid alterations, mainly concerning total and LDL cholesterol and less often HDL cholesterol, triglycerides, lipoprotein (a), apolipoprotein A1, and apolipoprotein B. In addition to quantitative, qualitative alterations of lipids have been also reported, including atherogenic and oxidized LDL and HDL particles. In thyroid disease, dyslipidemia coexists with various metabolic abnormalities and induce insulin resistance and oxidative stress via a vice-vicious cycle. The above associations in combination with the thyroid hormone induced hemodynamic alterations, might explain the increased risk of coronary artery disease, cerebral ischemia risk, and angina pectoris in older, and possibly ischemic stroke in younger patients with overt or subclinical hyperthyroidism

    Disease severity determines health-seeking behaviour amongst individuals with influenza-like illness in an internet-based cohort.

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    BACKGROUND: Seasonal influenza epidemics place considerable strain on health services. Robust systems of surveillance are therefore required to ensure preparedness. Sentinel surveillance does not accurately capture the community burden of epidemics as it misses cases that do not present to health services. In this study, Flusurvey (an internet-based community surveillance tool) was used to examine how severity of disease influences health-seeking behaviour in the UK. METHODS: Logistic regression with random effects was used to investigate the association between health-seeking and symptom severity, duration of illness and reduction in self-reported health-score over four flu seasons between 2011 and 2015. RESULTS: The majority of individuals did not seek care. In general, there was very strong evidence for an association between all severity indicators and visiting a health service (p < 0.0001). Being female (OR 1.62, 95% CI 1.23-2.14, p = 0.0003) and a self-diagnosis of the flu (OR 3.39, 95% CI 2.38-4.83, p < 0.0001) were also associated with increased likelihood of visiting a health service. During the 2012-13 and 2014-15 flu seasons, there was a significantly larger proportion of individuals with more severe sets of symptoms and a longer duration of illness. Despite this, the proportion of individuals with particular sets of symptoms visiting a health service showed only very slight variation across years. CONCLUSIONS: Traditional surveillance systems capture only the more severe episodes of illness. However, in spite of variation in flu activity, the proportion of individuals visiting a health service remains relatively stable within specific sets of symptoms across years. These data could be used in combination with data on consultation rates to provide better estimates of community burden

    Natural killer cells during acute HIV-1 infection: clues for HIV-1 prevention and therapy

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    Despite progress in preexposure prophylaxis, the number of newly diagnosed cases with HIV-1 remains high, highlighting the urgent need for preventive and therapeutic strategies to reduce HIV-1 acquisition and limit disease progression. Early immunological events, occurring during acute infection, are key determinants of the outcome and course of disease. Understanding early immune responses occurring before viral set-point is established, is critical to identify potential targets for prophylactic and therapeutic approaches. Natural killer (NK) cells represent a key cellular component of innate immunity and contribute to the early host defence against HIV-1 infection, modulating the pathogenesis of acute HIV-1 infection (AHI). Emerging studies have identified tools for harnessing NK cell responses and expanding specialized NK subpopulations with adaptive/memory features, paving the way for development of novel HIV-1 therapeutics. This review highlights the knowns and unknowns regarding the role of NK cell subsets in the containment of acute HIV-1 infection, and summarizes recent advances in selectively augmenting NK cell functions through prophylactic and therapeutic interventions

    The identification and validity of congenital malformation diagnoses in UK electronic health records: A systematic review

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    PURPOSE: To describe the methods used to identify and validate congenital malformation diagnoses recorded in UK electronic health records, and the results of validation studies. METHODS: Medline and Embase were searched for publications between 1987 and 2019 that involved identifying congenital malformations from UK electronic health records using diagnostic codes. The methods and code-lists used to identify congenital malformations, and the methods and results of validations, were examined. RESULTS: We retrieved 54 eligible studies; 36 identified congenital malformations from primary care data and 18 from secondary care data alone or in combination with birth and/or death records. Identification in secondary care data relied on codes from the 'Q' chapter for congenital malformations in ICD-10. In contrast, studies using primary care data frequently used additional codes outside of the 'P' chapter for congenital malformation diagnoses in Read, although the exact codes used were not always clear. Eight studies validated diagnoses identified in primary care data. The positive predictive value was highest (80-100%) for congenital malformations overall, major malformations, and heart defects although the validity of the reference standard used was often uncertain. It was lowest for neural tube defects (71%) and developmental hip dysplasia (56%). CONCLUSIONS: Studies identifying congenital malformations from primary care data provided limited details about the methods used. The few validation studies were limited to diagnoses recorded in primary care. Further assessments of all measures of validity in both data sources and of other malformation subgroups are needed, using robust reference standards and adhering to reporting guidelines. This article is protected by copyright. All rights reserved

    Combination of GPS and RTS measurements for the monitoring of semi-static and dynamic motion of pedestrian bridge

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    GPS and accelerometers have been broadly used the last decade for the monitoring of flexible structures and bridges, while Robotic Total Station (RTS) has been successfully assessed for the monitoring of slow and dynamic motions. Further experimental studies have revealed specific drawbacks of the GPS (multipath, etc.) and RTS (clipping, etc.) monitoring techniques and how these can be surpassed by their combined use. In the current study, we assess the performance of the complementary use of GPS and RTS for the monitoring of the semi-static and dynamic displacement of a relatively rigid pedestrian bridge, with main modal frequency more than 1Hz. Two RTS and GPS receivers were synchronised monitoring the deflection of the two sides of the mid-span of the bridge, while pedestrians excited the bridge. Several excitations (walking, marching, jumping, etc.) were examined, causing semi-static and/or dynamic displacement of the bridge, and rotation of the deck, of different amplitude and frequencies. The analysis of the RTS and GPS time-series, which was based on spectral analysis and band-pass filtering of the time-series, resulted to low- and high-frequency component expressing the semi-static and dynamic displacement. Finally, the combination of the GPS and RTS time-series made possible the estimation of 1-4mm semi-static displacement, the 5-10mm dynamic displacement and the estimation of the main modal frequencies
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