2,458 research outputs found
Evaluation of the MP Rapid 2019-NCOV IgM/IgG combo POCT test vs. an established platform-based method.
BACKGROUND: Accurate and rapid testing for SARS-COV-2 antibodies could improve the diagnosis and management of COVID-19. In this study, we aim to evaluate the diagnostic accuracy of a commercially available point-of-care lateral flow kit independently and in comparison to an established platform-based system. METHOD: Samples from 144 PCR-confirmed COVID-19 cases and 130 pre-pandemic negative controls were tested in parallel by MP Rapid 2019-NCOV IgM/IgG Combo test and Roche Elecsys. Comparison of results based on serum and capillary blood testing was undertaken. RESULTS: Sensitivity at day 15 onwards was 100% for both methods. Between days 1 and 7 post admission, the IgM/IgG Combo test and Roche Elecsys shown sensitivity of 74% (95%CI: 62%-85%) vs. 67% (95% CI: 55%-79%, P = 0.3947). Combo test specificities were 100% for IgG, 98.5% for IgM vs. Roche Elecsys specificity of 100%. Concordance analysis showed 98.5% agreement to the Roche Elecsys method (Cohen's Kappa 0.96 95% CI [0.92-0.99]). Capillary blood results showed complete agreement with serum samples using the Combo test. CONCLUSION: In comparison to Roche Elecsys, our data show that the MP Rapid 2019-NCOV IgM/IgG Combo test provides a high-confidence assay system for the detection of previous exposure to SARS-COV-2 infection with advantage of affording near-patient testing
The electric dipole response of Se above 4 MeV
The dipole response of Se in the energy range 4 to 9 MeV has been
analyzed using a polarized photon scattering
technique, performed at the High Intensity -Ray Source facility, to
complement previous work performed using unpolarized photons. The results of
this work offer both an enhanced sensitivity scan of the dipole response and an
unambiguous determination of the parities of the observed J=1 states. The
dipole response is found to be dominated by excitations, and can
reasonably be attributed to a pygmy dipole resonance. Evidence is presented to
suggest that a significant amount of directly unobserved excitation strength is
present in the region, due to unobserved branching transitions in the decays of
resonantly excited states. The dipole response of the region is underestimated
when considering only ground state decay branches. We investigate the electric
dipole response theoretically, performing calculations in a 3D cartesian-basis
time-dependent Skyrme-Hartree-Fock framework.Comment: 20 pages, 18 figures, to be submitted to PR
Pharmacological characterisation of anti-inflammatory compounds in acute and chronic mouse models of cigarette smoke-induced inflammation
<p>Abstract</p> <p>Background</p> <p>Candidate compounds being developed to treat chronic obstructive pulmonary disease are typically assessed using either acute or chronic mouse smoking models; however, in both systems compounds have almost always been administered prophylactically. Our aim was to determine whether the prophylactic effects of reference anti-inflammatory compounds in acute mouse smoking models reflected their therapeutic effects in (more clinically relevant) chronic systems.</p> <p>Methods</p> <p>To do this, we started by examining the type of inflammatory cell infiltrate which occurred after acute (3 days) or chronic (12 weeks) cigarette smoke exposure (CSE) using female, C57BL/6 mice (n = 7-10). To compare the effects of anti-inflammatory compounds in these models, mice were exposed to either 3 days of CSE concomitant with compound dosing or 14 weeks of CSE with dosing beginning after week 12. Budesonide (1 mg kg<sup>-1</sup>; i.n., q.d.), roflumilast (3 mg kg<sup>-1</sup>; p.o., q.d.) and fluvastatin (2 mg kg<sup>-1</sup>; p.o., b.i.d.) were dosed 1 h before (and 5 h after for fluvastatin) CSE. These dose levels were selected because they have previously been shown to be efficacious in mouse models of lung inflammation. Bronchoalveolar lavage fluid (BALF) leukocyte number was the primary endpoint in both models as this is also a primary endpoint in early clinical studies.</p> <p>Results</p> <p>To start, we confirmed that the inflammatory phenotypes were different after acute (3 days) versus chronic (12 weeks) CSE. The inflammation in the acute systems was predominantly neutrophilic, while in the more chronic CSE systems BALF neutrophils (PMNs), macrophage and lymphocyte numbers were all increased (p < 0.05). In the acute model, both roflumilast and fluvastatin reduced BALF PMNs (p < 0.01) after 3 days of CSE, while budesonide had no effect on BALF PMNs. In the chronic model, therapeutically administered fluvastatin reduced the numbers of PMNs and macrophages in the BALF (p ≤ 0.05), while budesonide had no effect on PMN or macrophage numbers, but did reduce BALF lymphocytes (p < 0.01). Roflumilast's inhibitory effects on inflammatory cell infiltrate were not statistically significant.</p> <p>Conclusions</p> <p>These results demonstrate that the acute, prophylactic systems can be used to identify compounds with therapeutic potential, but may not predict a compound's efficacy in chronic smoke exposure models.</p
Quantum Memories. A Review based on the European Integrated Project "Qubit Applications (QAP)"
We perform a review of various approaches to the implementation of quantum
memories, with an emphasis on activities within the quantum memory sub-project
of the EU Integrated Project "Qubit Applications". We begin with a brief
overview over different applications for quantum memories and different types
of quantum memories. We discuss the most important criteria for assessing
quantum memory performance and the most important physical requirements. Then
we review the different approaches represented in "Qubit Applications" in some
detail. They include solid-state atomic ensembles, NV centers, quantum dots,
single atoms, atomic gases and optical phonons in diamond. We compare the
different approaches using the discussed criteria.Comment: 22 pages, 12 figure
IgG Fc Receptors Provide an Alternative Infection Route for Murine Gamma-Herpesvirus-68
BACKGROUND: Herpesviruses can be neutralized in vitro but remain infectious in immune hosts. One difference between these settings is the availability of immunoglobulin Fc receptors. The question therefore arises whether a herpesvirus exposed to apparently neutralizing antibody can still infect Fc receptor(+) cells. PRINCIPAL FINDINGS: Immune sera blocked murine gamma-herpesvirus-68 (MHV-68) infection of fibroblasts, but failed to block and even enhanced its infection of macrophages and dendritic cells. Viral glycoprotein-specific monoclonal antibodies also enhanced infection. MHV-68 appeared to be predominantly latent in macrophages regardless of whether Fc receptors were engaged, but the infection was not abortive and new virus production soon overwhelmed infected cultures. Lytically infected macrophages down-regulated MHC class I-restricted antigen presentation, endocytosis and their response to LPS. CONCLUSIONS: IgG Fc receptors limit the neutralization of gamma-herpesviruses such as MHV-68
Post-Exposure Vaccination Improves Gammaherpesvirus Neutralization
Herpesvirus carriers transmit infection despite making virus-specific antibodies. Thus, their antibody responses are not necessarily optimal. An important question for infection control is whether vaccinating carriers might improve virus neutralization. The antibody response to murine gamma-herpesvirus-68 (MHV-68) blocks cell binding, but fails to block and even enhances an IgG Fc receptor-dependent infection of myeloid cells. Viral membrane fusion therefore remains intact. Although gH/gL-specific monoclonal antibodies can block infection at a post-binding step close to membrane fusion, gH/gL is a relatively minor antibody target in virus carriers. We show here that gH/gL-specific antibodies can block both Fc receptor-independent and Fc receptor-dependent infections, and that vaccinating virus carriers with a gH/gL fusion protein improves their capacity for virus neutralization both in vitro and in vivo. This approach has the potential to reduce herpesvirus transmission
Antecedents and consequences of effectuation and causation in the international new venture creation process
The selection of the entry mode in an international market is of key importance for the venture. A process-based perspective on entry mode selection can add to the International Business and International Entrepreneurship literature. Framing the international market entry as an entrepreneurial process, this paper analyzes the antecedents and consequences of causation and effectuation in the entry mode selection. For the analysis, regression-based techniques were used on a sample of 65 gazelles. The results indicate that experienced entrepreneurs tend to apply effectuation rather than causation, while uncertainty does not have a systematic influence. Entrepreneurs using causation-based international new venture creation processes tend to engage in export-type entry modes, while effectuation-based international new venture creation processes do not predetermine the entry mod
The RING-CH ligase K5 antagonizes restriction of KSHV and HIV-1 particle release by mediating ubiquitin-dependent endosomal degradation of tetherin
Tetherin (CD317/BST2) is an interferon-induced membrane protein that inhibits the release of diverse enveloped viral particles. Several mammalian viruses have evolved countermeasures that inactivate tetherin, with the prototype being the HIV-1 Vpu protein. Here we show that the human herpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV) is sensitive to tetherin restriction and its activity is counteracted by the KSHV encoded RING-CH E3 ubiquitin ligase K5. Tetherin expression in KSHV-infected cells inhibits viral particle release, as does depletion of K5 protein using RNA interference. K5 induces a species-specific downregulation of human tetherin from the cell surface followed by its endosomal degradation. We show that K5 targets a single lysine (K18) in the cytoplasmic tail of tetherin for ubiquitination, leading to relocalization of tetherin to CD63-positive endosomal compartments. Tetherin degradation is dependent on ESCRT-mediated endosomal sorting, but does not require a tyrosine-based sorting signal in the tetherin cytoplasmic tail. Importantly, we also show that the ability of K5 to substitute for Vpu in HIV-1 release is entirely dependent on K18 and the RING-CH domain of K5. By contrast, while Vpu induces ubiquitination of tetherin cytoplasmic tail lysine residues, mutation of these positions has no effect on its antagonism of tetherin function, and residual tetherin is associated with the trans-Golgi network (TGN) in Vpu-expressing cells. Taken together our results demonstrate that K5 is a mechanistically distinct viral countermeasure to tetherin-mediated restriction, and that herpesvirus particle release is sensitive to this mode of antiviral inhibition
Assessing and grading congestion in acute heart failure: a scientific statement from the acute heart failure committee of the heart failure association of the European society of cardiology and endorsed by the European society of intensive care medicine
Patients with acute heart failure (AHF) require urgent in-hospital treatment for relief of symptoms. The main reason for hospitalization is congestion, rather than low cardiac output. Although congestion is associated with a poor prognosis, many patients are discharged with persistent signs and symptoms of congestion and/or a high left ventricular filling pressure. Available data suggest that a pre-discharge clinical assessment of congestion is often not performed, and even when it is performed, it is not done systematically because no method to assess congestion prior to discharge has been validated. Grading congestion would be helpful for initiating and following response to therapy. We have reviewed a variety of strategies to assess congestion which should be considered in the care of patients admitted with HF. We propose a combination of available measurements of congestion. Key elements in the measurement of congestion include bedside assessment, laboratory analysis, and dynamic manoeuvres. These strategies expand by suggesting a routine assessment of congestion and a pre-discharge scoring system. A point system is used to quantify the degree of congestion. This score offers a new instrument to direct both current and investigational therapies designed to optimize volume status during and after hospitalization. In conclusion, this document reviews the available methods of evaluating congestion, provides suggestions on how to properly perform these measurements, and proposes a method to quantify the amount of congestion presen
The chemopreventive polyphenol Curcumin prevents hematogenous breast cancer metastases in immunodeficient mice
Dissemination of metastatic cells probably occurs long before diagnosis of the primary tumor. Metastasis during early phases of carcinogenesis in high risk patients is therefore a potential prevention target. The plant polyphenol Curcumin has been proposed for dietary prevention of cancer. We therefore examined its effects on the human breast cancer cell line MDA-MB-231 in vitro and in a mouse metastasis model. Curcumin strongly induces apoptosis in MDA- MB- 231 cells in correlation with reduced activation of the survival pathway NF kappa B, as a consequence of diminished I kappa B and p65 phosphorylation. Curcumin also reduces the expression of major matrix metalloproteinases (MMPs) due to reduced NF kappa B activity and transcriptional downregulation of AP-1. NF kappa B/p65 silencing is sufficient to downregulate c-jun and MMP expression. Reduced NF kappa B/AP-1 activity and MMP expression lead to diminished invasion through a reconstituted basement membrane and to a significantly lower number of lung metastases in immunodeficient mice after intercardiac injection of 231 cells (p=0.0035). 68% of Curcumin treated but only 17% of untreated animals showed no or very few lung metastases, most likely as a consequence of down-regulation of NF kappa B/AP-1 dependent MMP expression and direct apoptotic effects on circulating tumor cells but not on established metastases. Dietary chemoprevention of metastases appears therefore feasible. Copyright (c) 2007 S. Karger AG, Basel
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