250 research outputs found

    Clinical course and management of COVID-19 in the era of widespread population immunity

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    The clinical implications of COVID-19 have changed since SARS-CoV-2 first emerged in humans. The current high levels of population immunity, due to prior infection and/or vaccination, have been associated with a vastly decreased overall risk of severe disease. Some people, particularly those with immunocompromising conditions, remain at risk for severe outcomes. Through the course of the pandemic, variants with somewhat different symptom profiles from the original SARS-CoV-2 virus have emerged. The management of COVID-19 has also changed since 2020, with the increasing availability of evidence-based treatments in two main classes: antivirals and immunomodulators. Selecting the appropriate treatment(s) for patients with COVID-19 requires a deep understanding of the evidence and an awareness of the limitations of applying data that have been largely based on immune-naive populations to patients today who most likely have vaccine-derived and/or infection-derived immunity. In this Review, we provide a summary of the clinical manifestations and approaches to caring for adult patients with COVID-19 in the era of vaccine availability and the dominance of the Omicron subvariants, with a focus on the management of COVID-19 in different patient groups, including immunocompromised, pregnant, vaccinated and unvaccinated patients.Peer reviewe

    Neonatal Hypoglycemia in Diabetic Mothers: a Systematic Review

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    Hypoglycemia occurs in approximately 8-30% of neonates born to mothers with diabetes. The full extent of the individual and contextual risk factors of hypoglycemia remains unclear and no systematic review of the available studies exists to date. We identified published studies using PubMed and EBSCO host search engines. A modified STROBE statement was used to assess studies\u27 strengths, weaknesses, and generalizability. A total of 16 articles were eligible for full text review. The clinical risk factors in these studies were broadly classified into two: infant-related and mother-related risk factors. The identified infant-related risk factors were SGA, macrosomia, prematurity, lower cord blood glucose, ponderal index and male sex. On the other hand, mother-related risk factors includes maternal hyperglycemia, ethnic origin, diabetes diagnosed prior to 28 weeks of gestation, pre-pregnancy BMI of ≄ 25 kg/mÂČ, blood glucose, maternal diabetes type and maternal HbA1c. Irrespective of diabetes type, infants born to diabetic mothers appear to have a higher risk of developing hypoglycemia compare to those born to normal mothers. The overall evidence suggested that these studies mainly focus on the clinical characteristics of infants and mothers. Future research should focus on the identification of risk factors at the individual and contextual levels that can independently predict neonatal hypoglycemia. Appropriate emphasis should also be given to better define neonatal hypoglycemia

    Monopile foundation stiffness estimation of an instrumented offshore wind turbine through model updating

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    Rapid development of offshore wind foundation models has resulted in a large number of built structures with generally underestimated foundation stiffness properties and a need to update and validate both the individual structural models and the underlying foundation design frameworks. This paper outlines a structural health monitoring approach, based on the combination of output only structural health monitoring methods and model updating, to estimate foundation stiffness parameters using field monitored data. Field monitoring data from an offshore wind turbine under idling conditions, over a large monitoring period, are presented and operational modal analysis is applied to estimate the modal parameters. Those are compared to modal properties predicted by finite element models, employing either old (API/DNVGL) or new (PISA) foundation design properties, which are calibrated using geotechnical site investigation data. A new approach to interpret seabed level statically equivalent foundation stiffness, in terms of effective lateral and rotational stiffness against load eccentricity, is presented. Seabed level statically equivalent foundation properties are updated by comparison against the observed modal behaviour and the optimised foundation parameters are presented, demonstrating a close match to the predictions of the PISA method

    Room Temperature Metastability of Multilayer Graphene Oxide Films

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    International audienceGraphene oxide has multiple potential applications. The chemistry of graphene oxide and its response to external stimuli such as temperature and light are not well understood and only approximately controlled. This under- standing is crucial to enable future applications of this material. Here, a com- bined experimental and density functional theory study shows that multilayer graphene oxide produced by oxidizing epitaxial graphene via the Hummers method is a metastable material whose structure and chemistry evolve at room temperature with a characteristic relaxation time of about one month. At the quasi-equilibrium, graphene oxide reaches a nearly-stable reduced O/C ratio, and exhibits a structure intensively deprived of epoxide groups and enriched of hydroxyl groups. Our calculations show that the structural and chemical changes are driven by the availability of hydrogen in the oxidized graphitic sheets, which favors the reduction of epoxide groups and the formation of water molecules

    Class III antiarrhythmic drugs amiodarone and dronedarone impair KIR2.1 backward trafficking

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    Drug-induced ion channel trafficking disturbance can cause cardiac arrhythmias. The subcellular level at which drugs interfere in trafficking pathways is largely unknown. KIR2.1 inward rectifier channels, largely responsible for the cardiac inward rectifier current (IK1), are degraded in lysosomes. Amiodarone and dronedarone are class III antiarrhythmics. Chronic use of amiodarone, and to a lesser extent dronedarone, causes serious adverse effects to several organs and tissue types, including the heart. Both drugs have been described to interfere in the late-endosome/lysosome system. Here we defined the potential interference in KIR2.1 backward trafficking by amiodarone and dronedarone. Both drugs inhibited IK1 in isolated rabbit ventricular cardiomyocytes at supraclinical doses only. In HK-KWGF cells, both drugs dose- and time-dependently increased KIR2.1 expression (2.0 ± 0.2-fold with amiodarone: 10 ÎŒM, 24 hrs; 2.3 ± 0.3-fold with dronedarone: 5 ÎŒM, 24 hrs) and late-endosomal/lysosomal KIR2.1 accumulation. Increased KIR2.1 expression level was also observed in the presence of Nav1.5 co-expression. Augmented KIR2.1 protein levels and intracellular accumulation were also observed in COS-7, END-2, MES-1 and EPI-7 cells. Both drugs had no effect on Kv11.1 ion channel protein expression levels. Finally, amiodarone (73.3 ± 10.3% P < 0.05 at −120 mV, 5 ÎŒM) enhanced IKIR2.1 upon 24-hrs treatment, whereas dronedarone tended to increase IKIR2.1 and it did not reach significance (43.8 ± 5.5%, P = 0.26 at −120 mV; 2 ÎŒM). We conclude that chronic amiodarone, and potentially also dronedarone, treatment can result in enhanced IK1 by inhibiting KIR2.1 degradation

    Distinguishing mechanisms underlying EMT tristability

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    Abstract Background The Epithelial-Mesenchymal Transition (EMT) endows epithelial-looking cells with enhanced migratory ability during embryonic development and tissue repair. EMT can also be co-opted by cancer cells to acquire metastatic potential and drug-resistance. Recent research has argued that epithelial (E) cells can undergo either a partial EMT to attain a hybrid epithelial/mesenchymal (E/M) phenotype that typically displays collective migration, or a complete EMT to adopt a mesenchymal (M) phenotype that shows individual migration. The core EMT regulatory network - miR-34/SNAIL/miR-200/ZEB1 - has been identified by various studies, but how this network regulates the transitions among the E, E/M, and M phenotypes remains controversial. Two major mathematical models – ternary chimera switch (TCS) and cascading bistable switches (CBS) - that both focus on the miR-34/SNAIL/miR-200/ZEB1 network, have been proposed to elucidate the EMT dynamics, but a detailed analysis of how well either or both of these two models can capture recent experimental observations about EMT dynamics remains to be done. Results Here, via an integrated experimental and theoretical approach, we first show that both these two models can be used to understand the two-step transition of EMT - E→E/M→M, the different responses of SNAIL and ZEB1 to exogenous TGF-ÎČ and the irreversibility of complete EMT. Next, we present new experimental results that tend to discriminate between these two models. We show that ZEB1 is present at intermediate levels in the hybrid E/M H1975 cells, and that in HMLE cells, overexpression of SNAIL is not sufficient to initiate EMT in the absence of ZEB1 and FOXC2. Conclusions These experimental results argue in favor of the TCS model proposing that miR-200/ZEB1 behaves as a three-way decision-making switch enabling transitions among the E, hybrid E/M and M phenotypes

    Tamoxifen mechanically reprograms the tumor microenvironment via HIF‐1A and reduces cancer cell survival

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    The tumor microenvironment is fundamental to cancer progression, and the influence of its mechanical properties is increasingly being appreciated. Tamoxifen has been used for many years to treat estrogen‐positive breast cancer. Here we report that tamoxifen regulates the level and activity of collagen cross‐linking and degradative enzymes, and hence the organization of the extracellular matrix, via a mechanism involving both the G protein‐coupled estrogen receptor (GPER) and hypoxia‐inducible factor‐1 alpha (HIF‐1A). We show that tamoxifen reduces HIF‐1A levels by suppressing myosin‐dependent contractility and matrix stiffness mechanosensing. Tamoxifen also downregulates hypoxia‐regulated genes and increases vascularization in PDAC tissues. Our findings implicate the GPER/HIF‐1A axis as a master regulator of peri‐tumoral stromal remodeling and the fibrovascular tumor microenvironment and offer a paradigm shift for tamoxifen from a well‐established drug in breast cancer hormonal therapy to an alternative candidate for stromal targeting strategies in PDAC and possibly other cancers.See also: E Cortes et al (January 2019) andM Pein &amp; T Oskarsson (January 2019)EMBO Reports (2019) 20: e46557Peer reviewe

    Outcomes of COVID-19 related hospitalization among people with HIV in the ISARIC WHO Clinical Characterization Protocol (UK):a prospective observational study

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    BACKGROUND:Evidence is conflicting about how HIV modulates COVID-19. We compared the presentation characteristics and outcomes of adults with and without HIV who were hospitalized with COVID-19 at 207 centers across the United Kingdom and whose data were prospectively captured by the ISARIC WHO CCP study. METHODS:We used Kaplan-Meier methods and Cox regression to describe the association between HIV status and day-28 mortality, after separate adjustment for sex, ethnicity, age, hospital acquisition of COVID-19 (definite hospital acquisition excluded), presentation date, ten individual comorbidities, and disease severity at presentation (as defined by hypoxia or oxygen therapy). RESULTS:Among 47,592 patients, 122 (0.26%) had confirmed HIV infection and 112/122 (91.8%) had a record of antiretroviral therapy. At presentation, HIV-positive people were younger (median 56 versus 74 years; p<0.001) and had fewer comorbidities, more systemic symptoms and higher lymphocyte counts and C-reactive protein levels. The cumulative day-28 mortality was similar in the HIV-positive vs. HIV-negative groups (26.7% vs. 32.1%; p=0.16), but in those under 60 years of age HIV-positive status was associated with increased mortality (21.3% vs. 9.6%; p<0.001 [log-rank test]). Mortality was higher among people with HIV after adjusting for age (adjusted hazard ratio [aHR] 1.47, 95% confidence interval [CI] 1.01-2.14; p=0.05), and the association persisted after adjusting for the other variables (aHR 1.69; 95% CI 1.15-2.48; p=0.008) and when restricting the analysis to people aged <60 years (aHR 2.87; 95% CI 1.70-4.84; p<0.001). CONCLUSIONS:HIV-positive status was associated with an increased risk of day-28 mortality among patients hospitalized for COVID-19
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