577 research outputs found

    The influence of HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV-positive individuals

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    <p>Abstract</p> <p>Objective</p> <p>This study was performed to investigate the impact of HAART versus no HAART and nucleoside free versus nucleoside containing HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV/HCV co-infected patients. In addition a control group of HCV mono-infected patients undergoing anti-HCV therapy was evaluated.</p> <p>Methods</p> <p>Multicenter, partially randomized, controlled clinical trial. HIV-negative and -positive patients with chronic HCV infection were treated with pegylated interferon alfa-2a and ribavirin (800 - 1200 mg/day) for 24 - 48 weeks in one of four treatment arms: HIV-negative (A), HIV-positive without HAART (B) and HIV-positive on HAART (C). Patients within arm C were randomized to receive open label either a nucleoside containing (C1) or a nucleoside free HAART (C2).</p> <p>Results</p> <p>168 patients were available for analysis. By intent-to-treat analysis similar sustained virological response rates (SVR, negative HCV-RNA 24 weeks after the end of therapy) were observed comparing HIV-negative and -positive patients (54% vs. 54%, p = 1.000). Among HIV-positive patients SVR rates were similar between patients off and on HAART (57% vs. 52%, p = 0.708). Higher SVR rates were observed in patients on a nucleoside free HAART compared to patients on a nucleoside containing HAART, though confounding could not be ruled out and in the intent-to-treat analysis the difference was not statistically significant (64% vs. 46%, p = 0.209).</p> <p>Conclusions</p> <p>Similar response rates for HCV therapy can be achieved in HIV-positive and -negative patients. Patients on nucleoside free HAART reached at least equal rates of sustained virological response compared to patients on standard HAART.</p

    MultiBaC: A strategy to remove batch effects between different omic data types

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    [EN] Diversity of omic technologies has expanded in the last years together with the number of omic data integration strategies. However, multiomic data generation is costly, and many research groups cannot afford research projects where many different omic techniques are generated, at least at the same time. As most researchers share their data in public repositories, different omic datasets of the same biological system obtained at different labs can be combined to construct a multiomic study. However, data obtained at different labs or moments in time are typically subjected to batch effects that need to be removed for successful data integration. While there are methods to correct batch effects on the same data types obtained in different studies, they cannot be applied to correct lab or batch effects across omics. This impairs multiomic meta-analysis. Fortunately, in many cases, at least one omics platform-i.e. gene expression- is repeatedly measured across labs, together with the additional omic modalities that are specific to each study. This creates an opportunity for batch analysis. We have developed MultiBaC (multiomic Multiomics Batch-effect Correction correction), a strategy to correct batch effects from multiomic datasets distributed across different labs or data acquisition events. Our strategy is based on the existence of at least one shared data type which allows data prediction across omics. We validate this approach both on simulated data and on a case where the multiomic design is fully shared by two labs, hence batch effect correction within the same omic modality using traditional methods can be compared with the MultiBaC correction across data types. Finally, we apply MultiBaC to a true multiomic data integration problem to show that we are able to improve the detection of meaningful biological effects.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work is part of a research project that is totally funded by Conselleria d'Educacio, Cultura i Esport (Generalitat Valenciana) through PROMETEO grants program for excellence research groups.Ugidos, M.; Tarazona Campos, S.; Prats-Montalbán, JM.; Ferrer, A.; Conesa, A. (2020). MultiBaC: A strategy to remove batch effects between different omic data types. Statistical Methods in Medical Research. 29(10):2851-2864. https://doi.org/10.1177/0962280220907365S285128642910Kupfer, P., Guthke, R., Pohlers, D., Huber, R., Koczan, D., & Kinne, R. W. (2012). Batch correction of microarray data substantially improves the identification of genes differentially expressed in Rheumatoid Arthritis and Osteoarthritis. BMC Medical Genomics, 5(1). doi:10.1186/1755-8794-5-23Gregori, J., Villarreal, L., Méndez, O., Sánchez, A., Baselga, J., & Villanueva, J. (2012). Batch effects correction improves the sensitivity of significance tests in spectral counting-based comparative discovery proteomics. Journal of Proteomics, 75(13), 3938-3951. doi:10.1016/j.jprot.2012.05.005Ritchie, M. E., Phipson, B., Wu, D., Hu, Y., Law, C. W., Shi, W., & Smyth, G. K. (2015). limma powers differential expression analyses for RNA-sequencing and microarray studies. Nucleic Acids Research, 43(7), e47-e47. doi:10.1093/nar/gkv007Gagnon-Bartsch, J. A., & Speed, T. P. (2011). Using control genes to correct for unwanted variation in microarray data. Biostatistics, 13(3), 539-552. doi:10.1093/biostatistics/kxr034Nueda, M. j., Ferrer, A., & Conesa, A. (2011). ARSyN: a method for the identification and removal of systematic noise in multifactorial time course microarray experiments. Biostatistics, 13(3), 553-566. doi:10.1093/biostatistics/kxr042Jansen, J. J., Hoefsloot, H. C. J., van der Greef, J., Timmerman, M. E., Westerhuis, J. A., & Smilde, A. K. (2005). ASCA: analysis of multivariate data obtained from an experimental design. Journal of Chemometrics, 19(9), 469-481. doi:10.1002/cem.952Nueda, M. J., Conesa, A., Westerhuis, J. A., Hoefsloot, H. C. J., Smilde, A. K., Talón, M., & Ferrer, A. (2007). Discovering gene expression patterns in time course microarray experiments by ANOVA–SCA. Bioinformatics, 23(14), 1792-1800. doi:10.1093/bioinformatics/btm251Giordan, M. (2013). A Two-Stage Procedure for the Removal of Batch Effects in Microarray Studies. Statistics in Biosciences, 6(1), 73-84. doi:10.1007/s12561-013-9081-1Nyamundanda, G., Poudel, P., Patil, Y., & Sadanandam, A. (2017). A Novel Statistical Method to Diagnose, Quantify and Correct Batch Effects in Genomic Studies. Scientific Reports, 7(1). doi:10.1038/s41598-017-11110-6Reese, S. E., Archer, K. J., Therneau, T. M., Atkinson, E. J., Vachon, C. M., de Andrade, M., … Eckel-Passow, J. E. (2013). A new statistic for identifying batch effects in high-throughput genomic data that uses guided principal component analysis. Bioinformatics, 29(22), 2877-2883. doi:10.1093/bioinformatics/btt480Papiez, A., Marczyk, M., Polanska, J., & Polanski, A. (2018). BatchI: Batch effect Identification in high-throughput screening data using a dynamic programming algorithm. Bioinformatics, 35(11), 1885-1892. doi:10.1093/bioinformatics/bty900Keel, B. N., Zarek, C. M., Keele, J. W., Kuehn, L. A., Snelling, W. M., Oliver, W. T., … Lindholm-Perry, A. K. (2018). RNA-Seq Meta-analysis identifies genes in skeletal muscle associated with gain and intake across a multi-season study of crossbred beef steers. BMC Genomics, 19(1). doi:10.1186/s12864-018-4769-8Li, M. D., Burns, T. C., Morgan, A. A., & Khatri, P. (2014). Integrated multi-cohort transcriptional meta-analysis of neurodegenerative diseases. Acta Neuropathologica Communications, 2(1). doi:10.1186/s40478-014-0093-yAndres-Terre, M., McGuire, H. M., Pouliot, Y., Bongen, E., Sweeney, T. E., Tato, C. M., & Khatri, P. (2015). Integrated, Multi-cohort Analysis Identifies Conserved Transcriptional Signatures across Multiple Respiratory Viruses. Immunity, 43(6), 1199-1211. doi:10.1016/j.immuni.2015.11.003Sandhu, V., Labori, K. J., Borgida, A., Lungu, I., Bartlett, J., Hafezi-Bakhtiari, S., … Haibe-Kains, B. (2019). Meta-Analysis of 1,200 Transcriptomic Profiles Identifies a Prognostic Model for Pancreatic Ductal Adenocarcinoma. JCO Clinical Cancer Informatics, (3), 1-16. doi:10.1200/cci.18.00102Huang, H., Liu, C.-C., & Zhou, X. J. (2010). Bayesian approach to transforming public gene expression repositories into disease diagnosis databases. Proceedings of the National Academy of Sciences, 107(15), 6823-6828. doi:10.1073/pnas.0912043107Pelechano, V., & Pérez-Ortín, J. E. (2010). There is a steady-state transcriptome in exponentially growing yeast cells. Yeast, 27(7), 413-422. doi:10.1002/yea.1768Garcı́a-Martı́nez, J., Aranda, A., & Pérez-Ortı́n, J. E. (2004). Genomic Run-On Evaluates Transcription Rates for All Yeast Genes and Identifies Gene Regulatory Mechanisms. Molecular Cell, 15(2), 303-313. doi:10.1016/j.molcel.2004.06.004Pelechano, V., Chávez, S., & Pérez-Ortín, J. E. (2010). A Complete Set of Nascent Transcription Rates for Yeast Genes. PLoS ONE, 5(11), e15442. doi:10.1371/journal.pone.0015442Zid, B. M., & O’Shea, E. K. (2014). Promoter sequences direct cytoplasmic localization and translation of mRNAs during starvation in yeast. Nature, 514(7520), 117-121. doi:10.1038/nature13578Freeberg, M. A., Han, T., Moresco, J. J., Kong, A., Yang, Y.-C., Lu, Z., … Kim, J. K. (2013). Pervasive and dynamic protein binding sites of the mRNA transcriptome in Saccharomyces cerevisiae. Genome Biology, 14(2), R13. doi:10.1186/gb-2013-14-2-r13McKinlay, A., Araya, C. L., & Fields, S. (2011). Genome-Wide Analysis of Nascent Transcription in Saccharomyces cerevisiae. G3 Genes|Genomes|Genetics, 1(7), 549-558. doi:10.1534/g3.111.000810Castells-Roca, L., García-Martínez, J., Moreno, J., Herrero, E., Bellí, G., & Pérez-Ortín, J. E. (2011). Heat Shock Response in Yeast Involves Changes in Both Transcription Rates and mRNA Stabilities. PLoS ONE, 6(2), e17272. doi:10.1371/journal.pone.0017272Wold, S., Sjöström, M., & Eriksson, L. (2001). PLS-regression: a basic tool of chemometrics. Chemometrics and Intelligent Laboratory Systems, 58(2), 109-130. doi:10.1016/s0169-7439(01)00155-1Folch-Fortuny, A., Vitale, R., de Noord, O. E., & Ferrer, A. (2017). Calibration transfer between NIR spectrometers: New proposals and a comparative study. Journal of Chemometrics, 31(3), e2874. doi:10.1002/cem.2874García Muñoz, S., MacGregor, J. F., & Kourti, T. (2005). Product transfer between sites using Joint-Y PLS. Chemometrics and Intelligent Laboratory Systems, 79(1-2), 101-114. doi:10.1016/j.chemolab.2005.04.009Andrade, J. M., Gómez-Carracedo, M. P., Krzanowski, W., & Kubista, M. (2004). Procrustes rotation in analytical chemistry, a tutorial. Chemometrics and Intelligent Laboratory Systems, 72(2), 123-132. doi:10.1016/j.chemolab.2004.01.007Hurley, J. R., & Cattell, R. B. (2007). The procrustes program: Producing direct rotation to test a hypothesized factor structure. Behavioral Science, 7(2), 258-262. doi:10.1002/bs.3830070216Hartigan, J. A., & Wong, M. A. (1979). Algorithm AS 136: A K-Means Clustering Algorithm. Applied Statistics, 28(1), 100. doi:10.2307/234683

    Role of microbial biofilms in the maintenance of oral health and in the development of dental caries and periodontal diseases. Consensus report of group 1 of the Joint EFP/ORCA workshop on the boundaries between caries and periodontal disease.

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    BACKGROUND AND AIMS: The scope of this working group was to review (1) ecological interactions at the dental biofilm in health and disease, (2) the role of microbial communities in the pathogenesis of periodontitis and caries, and (3) the innate host response in caries and periodontal diseases. RESULTS AND CONCLUSIONS: A health-associated biofilm includes genera such as Neisseria, Streptococcus, Actinomyces, Veillonella and Granulicatella. Microorganisms associated with both caries and periodontal diseases are metabolically highly specialized and organized as multispecies microbial biofilms. Progression of these diseases involves multiple microbial interactions driven by different stressors. In caries, the exposure of dental biofilms to dietary sugars and their fermentation to organic acids results in increasing proportions of acidogenic and aciduric species. In gingivitis, plaque accumulation at the gingival margin leads to inflammation and increasing proportions of proteolytic and often obligately anaerobic species. The natural mucosal barriers and saliva are the main innate defence mechanisms against soft tissue bacterial invasion. Similarly, enamel and dentin are important hard tissue barriers to the caries process. Given that the present state of knowledge suggests that the aetiologies of caries and periodontal diseases are mutually independent, the elements of innate immunity that appear to contribute to resistance to both are somewhat coincidental

    phyloXML: XML for evolutionary biology and comparative genomics

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    <p>Abstract</p> <p>Background</p> <p>Evolutionary trees are central to a wide range of biological studies. In many of these studies, tree nodes and branches need to be associated (or annotated) with various attributes. For example, in studies concerned with organismal relationships, tree nodes are associated with taxonomic names, whereas tree branches have lengths and oftentimes support values. Gene trees used in comparative genomics or phylogenomics are usually annotated with taxonomic information, genome-related data, such as gene names and functional annotations, as well as events such as gene duplications, speciations, or exon shufflings, combined with information related to the evolutionary tree itself. The data standards currently used for evolutionary trees have limited capacities to incorporate such annotations of different data types.</p> <p>Results</p> <p>We developed a XML language, named phyloXML, for describing evolutionary trees, as well as various associated data items. PhyloXML provides elements for commonly used items, such as branch lengths, support values, taxonomic names, and gene names and identifiers. By using "property" elements, phyloXML can be adapted to novel and unforeseen use cases. We also developed various software tools for reading, writing, conversion, and visualization of phyloXML formatted data.</p> <p>Conclusion</p> <p>PhyloXML is an XML language defined by a complete schema in XSD that allows storing and exchanging the structures of evolutionary trees as well as associated data. More information about phyloXML itself, the XSD schema, as well as tools implementing and supporting phyloXML, is available at <url>http://www.phyloxml.org</url>.</p

    Common TNF-α, IL-1β, PAI-1, uPA, CD14 and TLR4 polymorphisms are not associated with disease severity or outcome from Gram negative sepsis

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    <p>Abstract</p> <p>Background</p> <p>Several studies have investigated single nucleotide polymorphisms (SNPs) in candidate genes associated with sepsis and septic shock with conflicting results. Only few studies have combined the analysis of multiple SNPs in the same population.</p> <p>Methods</p> <p>Clinical data and DNA from consecutive adult patients with culture proven Gram negative bacteremia admitted to a Danish hospital between 2000 and 2002. Analysis for commonly described SNPs of tumor necrosis-α, (TNF-α), interleukin-1β (IL-1β), plasminogen activator-1 (PAI-1), urokinase plasminogen activator (uPA), CD14 and toll-like receptor 4 (TLR4) was done.</p> <p>Results</p> <p>Of 319 adults, 74% had sepsis, 19% had severe sepsis and 7% were in septic shock. No correlation between severity or outcome of sepsis was observed for the analyzed SNPs of TNF-α, IL-1β, PAI-1, uPA, CD14 or TLR-4. In multivariate Cox proportional hazard regression analysis, increasing age, polymicrobial infection and haemoglobin levels were associated with in-hospital mortality.</p> <p>Conclusion</p> <p>We did not find any association between TNF-α, IL-1β, PAI-1, uPA, CD14 and TLR4 polymorphisms and outcome of Gram negative sepsis. Other host factors appear to be more important than the genotypes studied here in determining the severity and outcome of Gram negative sepsis.</p

    The yeast P5 type ATPase, Spf1, regulates manganese transport into the endoplasmic reticulum

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    The endoplasmic reticulum (ER) is a large, multifunctional and essential organelle. Despite intense research, the function of more than a third of ER proteins remains unknown even in the well-studied model organism Saccharomyces cerevisiae. One such protein is Spf1, which is a highly conserved, ER localized, putative P-type ATPase. Deletion of SPF1 causes a wide variety of phenotypes including severe ER stress suggesting that this protein is essential for the normal function of the ER. The closest homologue of Spf1 is the vacuolar P-type ATPase Ypk9 that influences Mn2+ homeostasis. However in vitro reconstitution assays with Spf1 have not yielded insight into its transport specificity. Here we took an in vivo approach to detect the direct and indirect effects of deleting SPF1. We found a specific reduction in the luminal concentration of Mn2+ in ∆spf1 cells and an increase following it’s overexpression. In agreement with the observed loss of luminal Mn2+ we could observe concurrent reduction in many Mn2+-related process in the ER lumen. Conversely, cytosolic Mn2+-dependent processes were increased. Together, these data support a role for Spf1p in Mn2+ transport in the cell. We also demonstrate that the human sequence homologue, ATP13A1, is a functionally conserved orthologue. Since ATP13A1 is highly expressed in developing neuronal tissues and in the brain, this should help in the study of Mn2+-dependent neurological disorders

    Inferring stabilizing mutations from protein phylogenies : application to influenza hemagglutinin

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    One selection pressure shaping sequence evolution is the requirement that a protein fold with sufficient stability to perform its biological functions. We present a conceptual framework that explains how this requirement causes the probability that a particular amino acid mutation is fixed during evolution to depend on its effect on protein stability. We mathematically formalize this framework to develop a Bayesian approach for inferring the stability effects of individual mutations from homologous protein sequences of known phylogeny. This approach is able to predict published experimentally measured mutational stability effects (ΔΔG values) with an accuracy that exceeds both a state-of-the-art physicochemical modeling program and the sequence-based consensus approach. As a further test, we use our phylogenetic inference approach to predict stabilizing mutations to influenza hemagglutinin. We introduce these mutations into a temperature-sensitive influenza virus with a defect in its hemagglutinin gene and experimentally demonstrate that some of the mutations allow the virus to grow at higher temperatures. Our work therefore describes a powerful new approach for predicting stabilizing mutations that can be successfully applied even to large, complex proteins such as hemagglutinin. This approach also makes a mathematical link between phylogenetics and experimentally measurable protein properties, potentially paving the way for more accurate analyses of molecular evolution
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