1,256 research outputs found

    Novel mutation in YMDD motif and direct neighbourhood in a child with chronic HBV-infection and clinical lamivudine and adefovir resistance - a scholarly case

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    <p>Abstract</p> <p>Context</p> <p>Chronic HBV infection is a major cause of hepatocellular carcinoma (HCC) which meanwhile has become the 5<sup>th </sup>most reason for a fatal outcome of cancer. Worldwide, approximately 350 million people are chronically HBV infected and as such of risk to develop HCC, of those an estimated high rate of children. Treatment of chronic infection is sufficient to reduce the rate of HCC but the rate of sustained virological response remains to low, not at least due to emergence of resistant virus strains. Less is known on HBV infection in children despite the extremely high rate of chronicity.</p> <p>Objective, Design, Setting, and Patient</p> <p>The case of a nine years old male with a 6 year history of chronic HBV infection, of those 5 years with antiviral treatment is described.</p> <p>Interventions and Main Outcome Measure(s)</p> <p>Before our lab was consulted, the patient was unsuccessfully treated with interferon, an obscure drug named Hepon, which should activate antiviral immune response, and Lamivudine, the latter most likely becoming ineffective due to the mergence of resistant subpopulations (rtL180 M, rtV207 M, two strains with stop codons at position rt188 and rt198, rtM204V (YVDD), rtM204K (YKDD)). Replacement of Lamivudine by adefovir displayed no advantage despite the lack of resistance mutations, thus no decrease in viremia was observed under adefovir treatment.</p> <p>Results and Conclusions</p> <p>Novel mutations in the YMDD motif and its direct neighbourhood were observed, both being compatible with Lamivudine resistance. No mutations were found that are associated with ADF resistance. Both, the clinical course of treatment and the genotypic resistance profile emphasize the need for systematic analyses of the HBV resistance mechanisms and structured therapy concept also for children chronically infected with HBV.</p

    Respiratory Infections by HMPV and RSV Are Clinically Indistinguishable but Induce Different Host Response in Aged Individuals

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    Background: Human metapneumovirus and respiratory syncytial virus can cause severe respiratory diseases, especially in infants, young children, and the elderly. So far it remains unclear why infections in the elderly become life threatening despite the presence of neutralizing antibodies in the serum, and to which extent double infections worsen the clinical course. Methods: Young and aged BALB/c-mice were infected with RSV or/and HMPV. Appearance of the mice was observed during course of infection. On day 5 p.i. animals were dispatched by cervical dislocation and levels of TNF-a and NF-kB were determined. Results: The observation of activity, weight and appearance of the different mice showed no differences among the tested groups. Despite this, the immunologic response depends on the animals ’ age and the virus they were infected with. In young animals, NF-kB levels were elevated if infected with HMPV and HMPV/RSV but remained low in RSV infections, whereas in aged animals the opposite was observed: solely RSV-infected animals showed elevated levels of NF-kB. TNF-a was slightly elevated in HMPV-infected young and old animals, but only in young animals this elevation was significant. Conclusions: Contrary to other studies, no weight loss or change in activity despite productive lung infection with the different viruses were observed. This may be due to the weaker anaesthesia or the lesser volume of virus solution used

    Detection of Head-to-Tail DNA Sequences of Human Bocavirus in Clinical Samples

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    Parvoviruses are single stranded DNA viruses that replicate in a so called “rolling-hairpin” mechanism, a variant of the rolling circle replication known for bacteriophages like ϕX174. The replication intermediates of parvoviruses thus are concatemers of head-to-head or tail-to-tail structure. Surprisingly, in case of the novel human bocavirus, neither head-to-head nor tail-to-tail DNA sequences were detected in clinical isolates; in contrast head-to-tail DNA sequences were identified by PCR and sequencing. Thereby, the head-to-tail sequences were linked by a novel sequence of 54 bp of which 20 bp also occur as conserved structures of the palindromic ends of parvovirus MVC which in turn is a close relative to human bocavirus

    Human bocavirus (HBoV) in children with respiratory tract infection by enzyme linked immunosorbent assay (ELISA) and qualitative polymerase chain reaction (PCR)

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    <p>Abstract</p> <p>Background</p> <p>Human bocavirus (HBoV) is a recently discovered parvovirus associated with mild to severe lower respiratory tract infections in children, the aim of the work was determination of human bocavirus in nasopharyngeal aspirate (NPA) of infants by qualitative PCR and determination of acute human bocavirus infection by estimation of immunoglobulin M (IgM) antibodies in serum by enzyme linked immunosorbent assay.</p> <p>Results</p> <p>Twenty two (22%) out of the 100 NPA specimens of the patients with respiratory manifestations were positive for HBoV by qualitative PCR, while ELISA revealed positive HBoV IgM antibodies in 18 (18%) patients who were also positive by PCR. Non of the controls were positive by both techniques. The correlation study between ELISA and PCR revealed high significant association, (p < 0.001, X<sup>2 </sup>= 36 and agreement = 96%). Also PCR detected 4 (18.1%) NPA samples as HBoV positive cases among the patients that were not identified by ELISA. This could be due to high sensitivity and efficacy of PCR. ELISA being less sensitive than RT-PCR, sensitivity was (81.8% vs 100%), the efficacy was 97.7% in ELISA versus 99.7% for RT-PCR.</p> <p>Conclusion</p> <p>HBoV infections could be diagnosed in NPA of children by conventional PCR as a rapid and sensitive technique. While ELISA was a reliable serologic analysis for diagnosis of acute HBoV infection by estimation IgM antibodies in serum.</p

    High-dose glucocorticoid treatment of near-fatal Bocavirus lung infection results in rapid recovery

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    Human Bocavirus(HBoV) has to be considered as life-threatening pathogen inadults with atypical pneumonia. Pulsed high-dose glucocorticoid-treatmentmay be beneficial in patients suffering from severe pulmonary disease caused by HBoV or other viruses

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Palaeozoic-Recent geological development and uplift of the Amanos Mountains (S Turkey) in the critically located northwesternmost corner of the Arabian continent

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    <p>We have carried out a several-year-long study of the Amanos Mountains, on the basis of which we present new sedimentary and structural evidence, which we combine with existing data, to produce the first comprehensive synthesis in the regional geological setting. The ca. N-S-trending Amanos Mountains are located at the northwesternmost edge of the Arabian plate, near the intersection of the African and Eurasian plates. Mixed siliciclastic-carbonate sediments accumulated on the north-Gondwana margin during the Palaeozoic. Triassic rift-related sedimentation was followed by platform carbonate deposition during Jurassic-Cretaceous. Late Cretaceous was characterised by platform collapse and southward emplacement of melanges and a supra-subduction zone ophiolite. Latest Cretaceous transgressive shallow-water carbonates gave way to deeper-water deposits during Palaeocene-Eocene. Eocene southward compression, reflecting initial collision, resulted in open folding, reverse faulting and duplexing. Fluvial, lagoonal and shallow-marine carbonates accumulated during Late Oligocene(?)-Early Miocene, associated with basaltic magmatism. Intensifying collision during Mid-Miocene initiated a foreland basin that then infilled with deep-water siliciclastic gravity flows. Late Miocene-Early Pliocene compression created mountain-sized folds and thrusts, verging E in the north but SE in the south. The resulting surface uplift triggered deposition of huge alluvial outwash fans in the west. Smaller alluvial fans formed along both mountain flanks during the Pleistocene after major surface uplift ended. Pliocene-Pleistocene alluvium was tilted towards the mountain front in the west. Strike-slip/transtension along the East Anatolian Transform Fault and localised sub-horizontal Quaternary basaltic volcanism in the region reflect regional transtension during Late Pliocene-Pleistocene (<4 Ma).</p

    Detection of human bocavirus and human metapneumovirus by real-time PCR from patients with respiratory symptoms in Southern Brazil

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    The introduction of newer molecular methods has led to the discovery of new respiratory viruses, such as human metapneumovirus (hMPV) and human bocavirus (hBoV), in respiratory tract specimens. We have studied the occurrence of hMPV and hBoV in the Porto Alegre (PA) metropolitan area, one of the southernmost cities of Brazil, evaluating children with suspected lower respiratory tract infection from May 2007-June 2008. A real-time polymerase chain reaction method was used for amplification and detection of hMPV and hBoV and to evaluate coinfections with respiratory syncytial virus (RSV), influenza A and B, parainfluenza 1, 2 and 3, human rhinovirus and human adenovirus. Of the 455 nasopharyngeal aspirates tested, hMPV was detected in 14.5% of samples and hBoV in 13.2%. A unique causative viral agent was identified in 46.2% samples and the coinfection rate was 43.7%. For hBoV, 98.3% of all positive samples were from patients with mixed infections. Similarly, 84.8% of all hMPV-positive results were also observed in mixed infections. Both hBoV and hMPV usually appeared with RSV. In summary, this is the first confirmation that hMPV and hBoV circulate in PA; this provides evidence of frequent involvement of both viruses in children with clinical signs of acute viral respiratory tract infection, although they mainly appeared as coinfection agents
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