700 research outputs found

    DNA Damage Response Protein CHK2 Regulates Metabolism in Liver Cancer

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    Defective mitosis with chromosome missegregation can have a dramatic effect on genome integrity by causing DNA damage, activation of the DNA damage response (DDR), and chromosomal instability. Although this is an energy-dependent process, mechanisms linking DDR to cellular metabolism are unknown. Here we show that checkpoint kinase 2 (CHK2), a central effector of DDR, regulates cellular energy production by affecting glycolysis and mitochondrial functions. Patients with hepatocellular carcinoma (HCC) had increased CHK2 mRNA in blood, which was associated with elevated tricarboxylic acid cycle (TCA) metabolites. CHK2 controlled expression of succinate dehydrogenase (SDH) and intervened with mitochondrial functions. DNA damage and CHK2 promoted SDH activity marked by increased succinate oxidation through the TCA cycle; this was confirmed in a transgenic model of HCC with elevated DNA damage. Mitochondrial analysis identified CHK2-controlled expression of SDH as key in sustaining reactive oxygen species production. Cells with DNA damage and elevated CHK2 relied significantly on glycolysis for ATP production due to dysfunctional mitochondria, which was abolished by CHK2 knockdown. This represents a vulnerability created by the DNA damage response that could be exploited for development of new therapies

    Incidence, etiology and predictors of adverse outcomes in 43,315 patients presenting to the Emergency Department with syncope: An international meta-analysis.

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    BACKGROUND: Syncope remains challenging for Emergency Department (ED) physicians due to difficulties in assessing the risk of future adverse outcomes. The aim of this meta-analysis is to establish the incidence and etiology of adverse outcomes as well as the predictors, in patients presenting with syncope to the ED. METHODS: A systematic electronic literature review was performed looking for eligible studies published between 1990 and 2010. Studies reporting multivariate predictors of adverse outcomes in patients presenting with syncope to the ED were included and pooled, when appropriate, using a random-effect method. Adverse events were defined as 'incidence of death, or of hospitalization and interventional procedures because of arrhythmias, ischemic heart disease or valvular heart disease'. RESULTS: 11 studies were included. Pooled analysis showed 42% (CI 95%; 32-52) of patients were admitted to hospital. Risk of death was 4.4% (CI 95%; 3.1-5.1) and 1.1% (CI 95%; 0.7-1.5) had a cardiovascular etiology. One third of patients were discharged without a diagnosis, while the most frequent diagnosis was 'situational, orthostatic or vasavagal syncope' in 29% (CI 95%; 12-47). 10.4% (CI 95%; 7.8-16) was diagnosed with heart disease, the most frequent type being bradyarrhythmia, 4.8% (CI 95%; 2.2-6.4) and tachyarrhythmia 2.6% (CI 95%; 1.1-3.1). Palpitations preceding syncope, exertional syncope, a history consistent of heart failure or ischemic heart disease, and evidence of bleeding were the most powerful predictors of an adverse outcome. CONCLUSION: Syncope carries a high risk of death, mainly related to cardiovascular disease. This large study which has established the most powerful predictors of adverse outcomes, may enable care and resources to be better focused at high risk patients. Copyright \ua9 2011 Elsevier Ireland Ltd. All rights reserved

    Computational Prediction of Heme-Binding Residues by Exploiting Residue Interaction Network

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    Computational identification of heme-binding residues is beneficial for predicting and designing novel heme proteins. Here we proposed a novel method for heme-binding residue prediction by exploiting topological properties of these residues in the residue interaction networks derived from three-dimensional structures. Comprehensive analysis showed that key residues located in heme-binding regions are generally associated with the nodes with higher degree, closeness and betweenness, but lower clustering coefficient in the network. HemeNet, a support vector machine (SVM) based predictor, was developed to identify heme-binding residues by combining topological features with existing sequence and structural features. The results showed that incorporation of network-based features significantly improved the prediction performance. We also compared the residue interaction networks of heme proteins before and after heme binding and found that the topological features can well characterize the heme-binding sites of apo structures as well as those of holo structures, which led to reliable performance improvement as we applied HemeNet to predicting the binding residues of proteins in the heme-free state. HemeNet web server is freely accessible at http://mleg.cse.sc.edu/hemeNet/

    FIB-FESEM and EMPA results on Antoninianus silver coins for manufacturing and corrosion processes

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    [EN] A set of ancient Antoninianus silver coins, dating back between 249 and 274¿A.D. and minted in Rome, Galliae, Orient and Ticinum, have been characterized. We use, for the first time, a combination of nano-invasive (focused ion beam-field emission scanning electron microscopy-X-ray microanalysis (FIB-FESEM-EDX), voltammetry of microparticles (VIMP)) and destructive techniques (scanning electron microscopy (SEM-EDX) and electron microprobe analysis (EMPA)) along with non-invasive, i.e., micro-Raman spectroscopy. The results revealed that, contrary to the extended belief, a complex Ag-Cu-Pb-Sn alloy was used. The use of alloys was common in the flourishing years of the Roman Empire. In the prosperous periods, Romans produced Ag-Cu alloys with relatively high silver content for the manufacture of both the external layers and inner nucleus of coins. This study also revealed that, although surface silvering processes were applied in different periods of crisis under the reign of Antoninii, even during crisis, Romans produced Antoninianus of high quality. Moreover, a first attempt to improve the silvering procedure using Hg-Ag amalgam has been identified.Financial support was provided by Sapienza University of Rome (Ateneo funding, 2014 15) and Spanish projects CTQ2014-53736-C3-1-P and CTQ2014-53736-C3-2-P, which are supported with Ministerio de Economía, Industria y Competitividad (MINECO) and Fondo Europeo de Desarrollo Regional (ERDF) funds, as well as project CTQ2017-85317-C2-1-P supported with funds from, MINECO, ERDF and Agencia Estatal de Investigación (AEI). PhD grants of the Department of Earth Sciences, Sapienza University of Rome, are gratefully acknowledgedDomenech Carbo, MT.; Di Turo, F.; Montoya, N.; Catalli, F.; Doménech Carbó, A.; De Vito, C. (2018). FIB-FESEM and EMPA results on Antoninianus silver coins for manufacturing and corrosion processes. Scientific Reports. 8. https://doi.org/10.1038/s41598-018-28990-xS8Doménech-Carbó, A., del Hoyo-Meléndez, J. M., Doménech-Carbó, M. T. & Piquero-Cilla, J. Electrochemical analysis of the first Polish coins using voltammetry of immobilized particles. Microchem. J. 130, 47–55 (2017).Di Turo, F. et al. Archaeometric analysis of Roman bronze coins from the Magna Mater temple using solid-state voltammetry and electrochemical impedance spectroscopy. Anal. Chim. Acta 955, 36–47 (2017).Doménech-Carbó, A., Doménech-Carbó, M. T. & Peiró-Ronda, M. A. Dating Archeological Lead Artifacts from Measurement of the Corrosion Content Using the Voltammetry of Microparticles. Anal. Chem. 83, 5639–5644 (2011).Giumlia-Mair, A. et al. Surface characterisation techniques in the study and conservation of art and archaeological artefacts: a review. Materials Technology 25(5), 245–261 (2010).Robbiola, L. & Portier, R. A global approach to the authentication of ancient bronzes based on the characterization of the alloy–patina–environment system. Journal of Cultural Heritage 7, 1–12 (2006).Campbell, W. Greek and Roman plated coins, Numismatics Notes and Monographs 57, American Numismatic Society, New York (1933).Kallithrakas-Kontos, N., Katsanos, A. A. & Touratsoglou, J. Trace element analysis of Alexander the Great’s silver tetradrachms minted in Macedonia, Nuclear Instruments and Methods in Physics. Research B 171, 342–349 (2000).Catalli, F. Numismatica greca e romana. (Libreria dello Stato, 2003).Cope, L. H. The Metallurgical development of the Roman Imperial Coinage during the first five centuries. (Liverpool, 1974).Scriptores Historiae Augustae. Historia Augusta. (The Perfect Library, 2014).Vlachou-Mogire, C., Stern, B. & McDonnell, J. G. The application of LA-ICP-MS in the examination of the thin plating layers found in late Roman coins. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 265, 558–568 (2007).Keturakis, C. J. et al. Analysis of corrosion layers in ancient Roman silver coins with high resolution surface spectroscopic techniques. Appl. Surf. Sci. 376, 241–251 (2016).Ingo, G. M. et al. Roman sophisticated surface modification methods to manufacture silver counterfeited coins. Appl. Surf. Sci. 1–11, https://doi.org/10.1016/j.apsusc.2017.01.101 (2017).La Niece, S. In: La Niece S. & Craddock, P. (Eds), Metal, Plating and Platination, Butterworth–Heinemann, London, 1993, p. 201.Anheuser, K. & France, P. Silver plating technology of the late 3rd century Roman coinage. Historical Metallurgy 36(1), 17–23 (2002).Anheuser, K. & Northover, P. Silver plating on Roman and Celtic coins from Britain– A technical study. The British Numismatic Journal 64, 22–32 (1994).Anheuser, K. 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Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 226, 153–162 (2004).Pardini, L. et al. X-ray fluorescence and laser-induced breakdown spectroscopy analysis of Roman silver denarii. Spectrochim. Acta - Part B At. Spectrosc. 74–75, 156–161 (2012).Klockenkämper, R., Bubert, H. & Hasler, K. Detection of near-surface silver enrichment on Roman imperial silver coins by x-ray spectral analysis. Archaeometry 41, 311–320 (1999).Ponting, M., Evans, J. A. & Pashley, V. Fingerprinting of roman mints using laser-amblation MC-ICP-MS lead isotope analysis.Del Hoyo-Meléndez, J. M. et al. Micro-XRF analysis of silver coins from medieval Poland. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 349, 6–16 (2015).Cesare Brandi. Il restauro. Teoria e pratica (1939–1986). (Editori Riuniti, 2009).Barberio, M., Veltri, S., Scisciò, M. & Antici, P. Laser-Accelerated Proton Beams as Diagnostics for Cultural Heritage. Sci. Rep. 7, 40415 (2017).Linke, R., Sehreiner, M., Demortier, G., Alram, M. & Winter, H. Non-Destructive Microanalysis of Cultural Heritage Materials. Comprehensive Analytical Chemistry 42, (Elsevier, 2004).Łojewska, J. et al. Recognizing ancient papyri by a combination of spectroscopic, diffractional and chromatographic analytical tools. Sci. Rep. 7, 46236 (2017).Meulebroeck, W., Wouters, H., Nys, K. & Thienpont, H. Authenticity screening of stained glass windows using optical spectroscopy. Nat. Sci. Reports 6 37726, 1–10 (2016).Martina, I., Wiesinger, R. & Schreiner, M. Micro-Raman Characterisation of Silver Corrosion Products: Instrumental Set Up and Reference. e-Preservation. Sci. Rep 9, 1–8 (2012).Rizzo, F. et al. Non-destructive determination of the silver content in Roman coins (nummi), dated to 308–311 A. D., by the combined use of PIXE-alpha, XRF and DPAA techniques. Microchem. J. 97, 286–290 (2011).Carl, M. & Young, M. L. Complementary analytical methods for analysis of Ag-plated cultural heritage objects. Microchem. J. 126, 307–315 (2016).Cepriá, G., Abadías, O., Pérez-Arantegui, J. & Castillo, J. R. Electrochemical Behavior of Silver-Copper Alloys in Voltammetry of Microparticles: A Simple Method for Screening Purposes. Electroanalysis 13, 477–483 (2001).Capelo, S., Homem, P. M., Cavalheiro, J. & Fonseca, I. T. E. Linear sweep voltammetry: a cheap and powerful technique for the identification of the silver tarnish layer constituents. J. Solid State Electrochem. 17, 223–234 (2013).Doménech-Carbó, A. et al. Detection of archaeological forgeries of Iberian lead plates using nanoelectrochemical techniques. The lot of fake plates from Bugarra (Spain). Forensic Sci. Int. 247, 79–88 (2015).Doménech-Carbó, A., Doménech-Carbó, M. T. & Peiró-Ronda, M. A. ‘One-Touch’ Voltammetry of Microparticles for the Identification of Corrosion Products in Archaeological Lead. Electroanalysis 23, 1391–1400 (2011).Doménech-Carbó, A., Doménech-Carbó, M. T., Montagna, E., Álvarez-Romero, C. & Lee, Y. Electrochemical discrimination of mints: The last Chinese emperors Kuang Hsü and Hsüan T’ung monetary unification. Talanta1 69, 50–56 (2017).Ager, F. J. et al. Combining XRF and GRT for the analysis of ancient silver coins. Microchem. J. 126, 149–154 (2016).Fawcett, T., Blanton, J., Blanton, T., Arias, L. & Suscavage, T. Non-destructive evaluation of Roman coin patinas from the 3rd and 4th century. Powder Diffraction, 1–10.Salvemini, F. et al. Neutron tomographic analysis: Material characterization of silver and electrum coins from the 6th and 5th centuries B.C. Mater. Charact. 118, 175–185 (2016).Ashkenazi, D., Gitler, H., Stern, A. & Tal, O. Metallurgical investigation on fourth century BCE silver jewellery of two hoards from Samaria. Sci. Rep. 7, 40659 (2017).Romano, F. P., Garraffo, S., Pappalardo, L. & Rizzo, F. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques. Spectrochim. Acta - Part B At. Spectrosc. 73, 13–19 (2012).Ingo, G. M. et al. Ancient Mercury-Based Plating Methods: Combined Use of Surface Analytical Techniques for the Study of Manufacturing Process and Degradation Phenomena. Accounts of Chemical Research 46(11), 2365–2375.Pouchou, J. L. & Pichoir, F.¨PAP¨ (ϕ–ρ–Z) procedure for improved quantitative microanalysis, in: Armstrong, J. T. (Ed.), Microbeam Analysis, San Francisco Press, San Francisco, pp. 104–106 (1985)

    Structural similarity-based predictions of protein interactions between HIV-1 and Homo sapiens

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    Abstract Background In the course of infection, viruses such as HIV-1 must enter a cell, travel to sites where they can hijack host machinery to transcribe their genes and translate their proteins, assemble, and then leave the cell again, all while evading the host immune system. Thus, successful infection depends on the pathogen's ability to manipulate the biological pathways and processes of the organism it infects. Interactions between HIV-encoded and human proteins provide one means by which HIV-1 can connect into cellular pathways to carry out these survival processes. Results We developed and applied a computational approach to predict interactions between HIV and human proteins based on structural similarity of 9 HIV-1 proteins to human proteins having known interactions. Using functional data from RNAi studies as a filter, we generated over 2000 interaction predictions between HIV proteins and 406 unique human proteins. Additional filtering based on Gene Ontology cellular component annotation reduced the number of predictions to 502 interactions involving 137 human proteins. We find numerous known interactions as well as novel interactions showing significant functional relevance based on supporting Gene Ontology and literature evidence. Conclusions Understanding the interplay between HIV-1 and its human host will help in understanding the viral lifecycle and the ways in which this virus is able to manipulate its host. The results shown here provide a potential set of interactions that are amenable to further experimental manipulation as well as potential targets for therapeutic intervention

    Salvage Liver Transplantation Is a Reasonable Option for Selected Patients Who Have Recurrent Hepatocellular Carcinoma after Liver Resection

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    Background: Salvage liver transplantation (SLT) has been reported as being feasible for patients who develop recurrent hepatocellular carcinoma (HCC) after primary liver resection, but this finding remains controversial. We retrospectively studied the clinical characteristics of SLT recipients and conducted a comparison between SLT recipients and primary liver transplantation (PLT) recipients. Methodology and Principal Findings: A retrospective study examined data from the China Liver Transplant Registry (CLTR) for 6,975 transplants performed from January 1999 to December 2009. A total of 6,087 patients underwent PLT and 888 patients underwent SLT for recurrence. Living donor liver transplantation (LDLT) was performed in 389 patients, while 6,586 patients underwent deceased donor liver transplantation (DDLT). Kaplan-Meier curves were used to compare survival rates. The 1-year, 3-year, and 5-year overall survival of SLT recipients was similar to that of PLT recipients: 73.00%, 51.77%, and 45.84 % vs. 74.49%, 55.10%, and 48.81%, respectively (P = 0.260). The 1-year, 3-year and 5-year disease-free survival of SLT recipients was inferior to that of PLT recipients: 64.79%, 45.57%, and 37.78 % vs. 66.39%, 50.39%, and 43.50%, respectively (P = 0.048). Similar survival results were observed for SLT and PLT within both the LDLT and DDLT recipients. Within the SLT group, the 1-year, 3-year, and 5-year overall survival for LDLT and DDLT recipients was similar: 93.33%, 74.67%, and 74.67 % vs. 80.13%, 62.10%, and 54.18 % (P = 0.281), as was the disease-free survival: 84.85%, 62.85%, an

    X-ray emission from the Sombrero galaxy: discrete sources

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    We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    The EEG signature of sensory evidence accumulation during decision formation closely tracks subjective perceptual experience

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    How neural representations of low-level visual information are accessed by higher-order processes to inform decisions and give rise to conscious experience is a longstanding question. Research on perceptual decision making has revealed a late event-related EEG potential (the Centro-Parietal Positivity, CPP) to be a correlate of the accumulation of sensory evidence. We tested how this evidence accumulation signal relates to externally presented (physical) and internally experienced (subjective) sensory evidence. Our results show that the known relationship between the physical strength of the external evidence and the evidence accumulation signal (reflected in the CPP amplitude) is mediated by the level of subjective experience of stimulus strength. This shows that the CPP closely tracks the subjective perceptual evidence, over and above the physically presented evidence. We conclude that a remarkably close relationship exists between the evidence accumulation process (i.e. CPP) and subjective perceptual experience, suggesting that neural decision processes and components of conscious experience are tightly linked

    Bipolar multiplex families have an increased burden of common risk variants for psychiatric disorders

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    Multiplex families with a high prevalence of a psychiatric disorder are often examined to identify rare genetic variants with large effect sizes. In the present study, we analysed whether the risk for bipolar disorder (BD) in BD multiplex families is influenced by common genetic variants. Furthermore, we investigated whether this risk is conferred mainly by BD-specific risk variants or by variants also associated with the susceptibility to schizophrenia or major depression. In total, 395 individuals from 33 Andalusian BD multiplex families (166 BD, 78 major depressive disorder, 151 unaffected) as well as 438 subjects from an independent, BD case/control cohort (161 unrelated BD, 277 unrelated controls) were analysed. Polygenic risk scores (PRS) for BD, schizophrenia (SCZ), and major depression were calculated and compared between the cohorts. Both the familial BD cases and unaffected family members had higher PRS for all three psychiatric disorders than the independent controls, with BD and SCZ being significant after correction for multiple testing, suggesting a high baseline risk for several psychiatric disorders in the families. Moreover, familial BD cases showed significantly higher BD PRS than unaffected family members and unrelated BD cases. A plausible hypothesis is that, in multiplex families with a general increase in risk for psychiatric disease, BD development is attributable to a high burden of common variants that confer a specific risk for BD. The present analyses demonstrated that common genetic risk variants for psychiatric disorders are likely to contribute to the high incidence of affective psychiatric disorders in the multiplex families. However, the PRS explained only part of the observed phenotypic variance, and rare variants might have also contributed to disease development
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