54 research outputs found

    TCF1(+) hepatitis C virus-specific CD8(+) T cells are maintained after cessation of chronic antigen stimulation.

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    Differentiation and fate of virus-specific CD8(+) T cells after cessation of chronic antigen stimulation is unclear. Here we show that a TCF1(+)CD127(+)PD1(+) hepatitis C virus (HCV)-specific CD8(+) T-cell subset exists in chronically infected patients with phenotypic features of T-cell exhaustion and memory, both before and after treatment with direct acting antiviral (DAA) agents. This subset is maintained during, and for a long duration after, HCV elimination. After antigen re-challenge the less differentiated TCF1(+)CD127(+)PD1(+) population expands, which is accompanied by emergence of terminally exhausted TCF1-CD127-PD1(hi) HCV-specific CD8(+) T cells. These results suggest the TCF1(+)CD127(+)PD1(+) HCV-specific CD8(+) T-cell subset has memory-like characteristics, including antigen-independent survival and recall proliferation. We thus provide evidence for the establishment of memory-like virus-specific CD8(+) T cells in a clinically relevant setting of chronic viral infection and we uncover their fate after cessation of chronic antigen stimulation, implicating a potential strategy for antiviral immunotherapy

    Serum heparan sulfate levels are elevated in endotoxemia

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    <p>Abstract</p> <p>Background</p> <p>Increased vascular permeability is a characteristic feature of sepsis which, in the past, has been ascribed exclusively to a malfunction of endothelial cells. However, recently it has become evident that the endothelial glycocalyx is of considerable importance concerning various aspects of vascular physiology, e.g. the vascular barrier and inflammation. Heparan sulfate, one of its essential components is characteristically traceable in blood, in case the endothelial glycocalyx is damaged or destroyed.</p> <p>Methods</p> <p>In 15 pigs we investigated whether the administration of endotoxin from gram-negative bacteria (Escherichia coli) results in increased serum levels of heparan sulfate, signalizing a shedding of the glycocalyx. In addition, markers of inflammation (white blood cell count, platelet count, tumour necrosis factor-α and interleukin-6) were evaluated over an observation period of 6 hours.</p> <p>Results</p> <p>Serum heparan sulfate concentrations significantly increased over time in the endotoxin group and were significantly elevated in comparison to the control group 6 hours after administration of endotoxin (p < 0.001). In the endotoxin group all markers of inflammation significantly changed during the time course.</p> <p>Conclusions</p> <p>The administration of bacterial endotoxin induced a significant rise in degradation products of the endothelial glycocalyx.</p

    Improved ventricular function during inhalation of PGI(2) aerosol partly relies on enhanced myocardial contractility

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    Inhaled prostacyclin (PGI(2)) aerosol induces selective pulmonary vasodilation. Further, it improves right ventricular ( RV) function, which may largely rely on pulmonary vasodilation, but also on enhanced myocardial contractility. We investigated the effects of the inhaled PGI(2) analogs epoprostenol (EPO) and iloprost (ILO) on RV function and myocardial contractility in 9 anesthetized pigs receiving aerosolized EPO (25 and 50 ng center dot kg(-1) center dot min(-1)) and, consecutively, ILO (60 ng center dot kg(-1) center dot min(-1)) for 20 min each. We measured pulmonary artery pressure ( PAP), RV ejection fraction (RVEF) and RV end-diastolic-volume (RV-EDV), and left ventricular end-systolic pressure-volume-relation (end-systolic elastance, E-es). EPO and ILO reduced PAP, increased RVEF and reduced RVEDV. E-es was enhanced during all doses tested, which reached statistical significance during EPO25ng and ILO, but not during EPO50ng. PGI(2) aerosol enhances myocardial contractility in healthy pigs, contributing to improve RV function. Copyright (C) 2005 S. Karger AG, Basel

    Calibration and Characterization of the IceCube Photomultiplier Tube

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    Over 5,000 PMTs are being deployed at the South Pole to compose the IceCube neutrino observatory. Many are placed deep in the ice to detect Cherenkov light emitted by the products of high-energy neutrino interactions, and others are frozen into tanks on the surface to detect particles from atmospheric cosmic ray showers. IceCube is using the 10-inch diameter R7081-02 made by Hamamatsu Photonics. This paper describes the laboratory characterization and calibration of these PMTs before deployment. PMTs were illuminated with pulses ranging from single photons to saturation level. Parameterizations are given for the single photoelectron charge spectrum and the saturation behavior. Time resolution, late pulses and afterpulses are characterized. Because the PMTs are relatively large, the cathode sensitivity uniformity was measured. The absolute photon detection efficiency was calibrated using Rayleigh-scattered photons from a nitrogen laser. Measured characteristics are discussed in the context of their relevance to IceCube event reconstruction and simulation efforts.Comment: 40 pages, 12 figure

    Squalene epoxidase, located on chromosome 8q24.1, is upregulated in 8q+ breast cancer and indicates poor clinical outcome in stage I and II disease

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    Gains of chromosomes 7p and 8q are associated with poor prognosis among oestrogen receptor-positive (ER+) stage I/II breast cancer. To identify transcriptional changes associated with this breast cancer subtype, we applied suppression subtractive hybridisation method to analyse differentially expressed genes among six breast tumours with and without chromosomal 7p and 8q gains. Identified mRNAs were validated by real-time RT–PCR in tissue samples obtained from 186 patients with stage I/II breast cancer. Advanced statistical methods were applied to identify associations of mRNA expression with distant metastasis-free survival (DMFS). mRNA expression of the key enzyme of cholesterol biosynthesis, squalene epoxidase (SQLE, chromosomal location 8q24.1), was associated with ER+ 7p+/8q+ breast cancer. Distant metastasis-free survival in stage I/II breast cancer cases was significantly inversely related to SQLE mRNA in multivariate Cox analysis (P<0.001) in two independent patient cohorts of 160 patients each. The clinically favourable group associated with a low SQLE mRNA expression could be further divided by mRNA expression levels of the oestrogen-regulated zinc transporter LIV-1. The data strongly support that SQLE mRNA expression might indicate high-risk ER+ stage I/II breast cancers. Further studies on tumour tissue from standardised treated patients, for example with tamoxifen, may validate the role of SQLE as a novel diagnostic parameter for ER+ early stage breast cancers

    Measurement of acoustic attenuation in South Pole ice

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    Using the South Pole Acoustic Test Setup (SPATS) and a retrievable transmitter deployed in holes drilled for the IceCube experiment, we have measured the attenuation of acoustic signals by South Pole ice at depths between 190 m and 500 m. Three data sets, using different acoustic sources, have been analyzed and give consistent results. The method with the smallest systematic uncertainties yields an amplitude attenuation coefficient α = 3.20 ± 0.57 km−1 between 10 and 30 kHz, considerably larger than previous theoretical estimates. Expressed as an attenuation length, the analyses give a consistent result for λ ≡ 1/α of ∌300 m with 20% uncertainty. No significant depth or frequency dependence has been found

    Time-integrated Searches for Point-like Sources of Neutrinos with the 40-string IceCube Detector

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