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  • 1
    Publication Date: 2012-02-17
    Description: Motivation: High-throughput sequencing (HTS) technologies have made low-cost sequencing of large numbers of samples commonplace. An explosion in the type, not just number, of sequencing experiments has also taken place including genome re-sequencing, population-scale variation detection, whole transcriptome sequencing and genome-wide analysis of protein-bound nucleic acids. Results: We present Artemis as a tool for integrated visualization and computational analysis of different types of HTS datasets in the context of a reference genome and its corresponding annotation. Availability: Artemis is freely available (under a GPL licence) for download (for MacOSX, UNIX and Windows) at the Wellcome Trust Sanger Institute websites: http://www.sanger.ac.uk/resources/software/artemis/ . Contact: artemis@sanger.ac.uk ; tjc@sanger.ac.uk
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  • 2
    Publication Date: 2012-02-17
    Description: : microRibonucleic acid (miRNAs) are small regulatory molecules that act by mRNA degradation or via translational repression. Although many miRNAs are ubiquitously expressed, a small subset have differential expression patterns that may give rise to tissue-specific complexes. Motivation: This work studies gene targeting patterns amongst miRNAs with differential expression profiles, and links this to control and regulation of protein complexes. Results: We find that, when a pair of miRNAs are not expressed in the same tissues, there is a higher tendency for them to target the direct partners of the same hub proteins. At the same time, they also avoid targeting the same set of hub-spokes. Moreover, the complexes corresponding to these hub-spokes tend to be specific and nonoverlapping. This suggests that the effect of miRNAs on the formation of complexes is specific. Contact: wongls@comp.nus.edu.sg Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 3
    Publication Date: 2012-02-17
    Description: Motivation: Small interfering RNAs (siRNAs) are produced from much longer sequences of double-stranded RNA precursors through cleavage by Dicer or a Dicer-like protein. These small RNAs play a key role in genetic and epigenetic regulation; however, a full understanding of the mechanisms by which they operate depends on the characterization of the precursors from which they are derived. Results: High-throughput sequencing of small RNA populations allows the locations of the double-stranded RNA precursors to be inferred. We have developed methods to analyse small RNA sequencing data from multiple biological sources, taking into account replicate information, to identify robust sets of siRNA precursors. Our methods show good performance on both a set of small RNA sequencing data in Arabidopsis thaliana and simulated datasets. Availability: Our methods are available as the Bioconductor ( www.bioconductor.org ) package segmentSeq (version 1.5.6 and above). Contact: tjh48@cam.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 4
    Publication Date: 2012-02-17
    Description: Motivation: Intrinsically disordered regions are key for the function of numerous proteins, and the scant available experimental annotations suggest the existence of different disorder flavors. While efficient predictions are required to annotate entire genomes, most existing methods require sequence profiles for disorder prediction, making them cumbersome for high-throughput applications. Results: In this work, we present an ensemble of protein disorder predictors called ESpritz. These are based on bidirectional recursive neural networks and trained on three different flavors of disorder, including a novel NMR flexibility predictor. ESpritz can produce fast and accurate sequence-only predictions, annotating entire genomes in the order of hours on a single processor core. Alternatively, a slower but slightly more accurate ESpritz variant using sequence profiles can be used for applications requiring maximum performance. Two levels of prediction confidence allow either to maximize reasonable disorder detection or to limit expected false positives to 5%. ESpritz performs consistently well on the recent CASP9 data, reaching a S w measure of 54.82 and area under the receiver operator curve of 0.856. The fast predictor is four orders of magnitude faster and remains better than most publicly available CASP9 methods, making it ideal for genomic scale predictions. Conclusions: ESpritz predicts three flavors of disorder at two distinct false positive rates, either with a fast or slower and slightly more accurate approach. Given its state-of-the-art performance, it can be especially useful for high-throughput applications. Availability: Both a web server for high-throughput analysis and a Linux executable version of ESpritz are available from: http://protein.bio.unipd.it/espritz/ Contact: silvio.tosatto@unipd.it Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 5
    Publication Date: 2012-02-17
    Description: Motivation: Clustering protein structures is an important task in structural bioinformatics. De novo structure prediction, for example, often involves a clustering step for finding the best prediction. Other applications include assigning proteins to fold families and analyzing molecular dynamics trajectories. Results: We present Pleiades, a novel approach to clustering protein structures with a rigorous mathematical underpinning. The method approximates clustering based on the root mean square deviation by first mapping structures to Gauss integral vectors—which were introduced by Røgen and co-workers—and subsequently performing K-means clustering. Conclusions: Compared to current methods, Pleiades dramatically improves on the time needed to perform clustering, and can cluster a significantly larger number of structures, while providing state-of-the-art results. The number of low energy structures generated in a typical folding study, which is in the order of 50 000 structures, can be clustered within seconds to minutes. Contact: thamelry@binf.ku.dk ; harder@binf.ku.dk Supplementary Information: Supplementary data are available at Bioinformatics online.
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  • 6
    Publication Date: 2012-02-17
    Description: Motivation: Transmembrane β barrel proteins (TMBs) are found in the outer membrane of Gram-negative bacteria, chloroplast and mitochondria. They play a major role in the translocation machinery, pore formation, membrane anchoring and ion exchange. TMBs are also promising targets for antimicrobial drugs and vaccines. Given the difficulty in membrane protein structure determination, computational methods to identify TMBs and predict the topology of TMBs are important. Results: Here, we present BOCTOPUS; an improved method for the topology prediction of TMBs by employing a combination of support vector machines (SVMs) and Hidden Markov Models (HMMs). The SVMs and HMMs account for local and global residue preferences, respectively. Based on a 10-fold cross-validation test, BOCTOPUS performs better than all existing methods, reaching a Q3 accuracy of 87%. Further, BOCTOPUS predicted the correct number of strands for 83% proteins in the dataset. BOCTOPUS might also help in reliable identification of TMBs by using it as an additional filter to methods specialized in this task. Availability: BOCTOPUS is freely available as a web server at: http://boctopus.cbr.su.se/ . The datasets used for training and evaluations are also available from this site. Contact: arne@bioinfo.se Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 7
    Publication Date: 2012-02-17
    Description: Motivation: High-dimensional data such as microarrays have created new challenges to traditional statistical methods. One such example is on class prediction with high-dimension, low-sample size data. Due to the small sample size, the sample mean estimates are usually unreliable. As a consequence, the performance of the class prediction methods using the sample mean may also be unsatisfactory. To obtain more accurate estimation of parameters some statistical methods, such as regularizations through shrinkage, are often desired. Results: In this article, we investigate the family of shrinkage estimators for the mean value under the quadratic loss function. The optimal shrinkage parameter is proposed under the scenario when the sample size is fixed and the dimension is large. We then construct a shrinkage-based diagonal discriminant rule by replacing the sample mean by the proposed shrinkage mean. Finally, we demonstrate via simulation studies and real data analysis that the proposed shrinkage-based rule outperforms its original competitor in a wide range of settings. Contact: tongt@hkbu.edu.hk
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  • 8
    Publication Date: 2012-02-17
    Description: Motivation: The advent of high-throughput sequencing technologies is revolutionizing our ability in discovering and genotyping DNA copy number variants (CNVs). Read count-based approaches are able to detect CNV regions with an unprecedented resolution. Although this computational strategy has been recently introduced in literature, much work has been already done for the preparation, normalization and analysis of this kind of data. Results: Here we face the many aspects that cover the detection of CNVs by using read count approach. We first study the characteristics and systematic biases of read count distributions, focusing on the normalization methods designed for removing these biases. Subsequently, we compare the algorithms designed to detect the boundaries of CNVs and we investigate the ability of read count data to predict the exact number of DNA copy. Finally, we review the tools publicly available for analysing read count data. To better understand the state of the art of read count approaches, we compare the performance of the three most widely used sequencing technologies (Illumina Genome Analyzer, Roche 454 and Life Technologies SOLiD) in all the analyses that we perform. Contact: albertomagi@gmail.com Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 9
    Publication Date: 2012-02-17
    Description: Motivation: We investigate and quantify the generalizability of the white blood cell (WBC) transcriptome to the general, multiorgan transcriptome. We use data from the NCBI's Gene Expression Omnibus (GEO) public repository to define two datasets for comparison, WBC and OO (Other Organ) sets. Results: Comprehensive pair-wise correlation and expression level profiles are calculated for both datasets (with sizes of 81 and 1463, respectively). We have used mapping and ranking across the Gene Ontology (GO) categories to quantify similarity between the two sets. GO mappings of the most correlated and highly expressed genes from the two datasets tightly match, with the notable exceptions of components of the ribosome, cell adhesion and immune response. That is, 10 877 or 48.8% of all measured genes do not change 〉10% of rank range between WBC and OO; only 878 (3.9%) change rank 〉50%. Two trans -tissue gene lists are defined, the most changing and the least changing genes in expression rank. We also provide a general, quantitative measure of the probability of expression rank and correlation profile in the OO system given the expression rank and correlation profile in the WBC dataset. Contact: vvaltchinov@partners.org Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 10
    Publication Date: 2012-02-17
    Description: Motivation: The understanding of the molecular sources for diseases like cancer can be significantly improved by computational models. Recently, Boolean networks have become very popular for modeling signaling and regulatory networks. However, such models rely on a set of Boolean functions that are in general not known. Unfortunately, while detailed information on the molecular interactions becomes available in large scale through electronic databases, the information on the Boolean functions does not become available simultaneously and has to be included manually into the models, if at all known. Results: We propose a new Boolean approach which can directly utilize the mechanistic network information available through modern databases. The Boolean function is implicitly defined by the reaction mechanisms. Special care has been taken for the treatment of kinetic features like inhibition. The method has been applied to a signaling model combining the Wnt and MAPK pathway. Availability: A sample C++ implementation of the proposed method is available for Linux and compatible systems through http://code.google.com/p/libscopes/wiki/Paper2011 Contact: handorf@physik.hu-berlin.de Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 11
    Publication Date: 2012-02-17
    Description: Motivation: Multiple sequence alignment (MSA) is a core method in bioinformatics. The accuracy of such alignments may influence the success of downstream analyses such as phylogenetic inference, protein structure prediction, and functional prediction. The importance of MSA has lead to the proliferation of MSA methods, with different objective functions and heuristics to search for the optimal MSA. Different methods of inferring MSAs produce different results in all but the most trivial cases. By measuring the differences between inferred alignments, we may be able to develop an understanding of how these differences (i) relate to the objective functions and heuristics used in MSA methods, and (ii) affect downstream analyses. Results: We introduce four metrics to compare MSAs, which include the position in a sequence where a gap occurs or the location on a phylogenetic tree where an insertion or deletion (indel) event occurs. We use both real and synthetic data to explore the information given by these metrics and demonstrate how the different metrics in combination can yield more information about MSA methods and the differences between them. Availability: MetAl is a free software implementation of these metrics in Haskell. Source and binaries for Windows, Linux and Mac OS X are available from http://kumiho.smith.man.ac.uk/whelan/software/metal/ . Contact: simon.whelan@manchester.ac.uk
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  • 12
    Publication Date: 2012-02-17
    Description: Motivation: Peptide detection is a crucial step in mass spectrometry (MS) based proteomics. Most existing algorithms are based upon greedy isotope template matching and thus may be prone to error propagation and ineffective to detect overlapping peptides. In addition, existing algorithms usually work at different charge states separately, isolating useful information that can be drawn from other charge states, which may lead to poor detection of low abundance peptides. Results: BPDA2d models spectra as a mixture of candidate peptide signals and systematically evaluates all possible combinations of possible peptide candidates to interpret the given spectra. For each candidate, BPDA2d takes into account its elution profile, charge state distribution and isotope pattern, and it combines all evidence to infer the candidate's signal and existence probability. By piecing all evidence together—especially by deriving information across charge states—low abundance peptides can be better identified and peptide detection rates can be improved. Instead of local template matching, BPDA2d performs global optimization for all candidates and systematically optimizes their signals. Since BPDA2d looks for the optimal among all possible interpretations of the given spectra, it has the capability in handling complex spectra where features overlap. BPDA2d estimates the posterior existence probability of detected peptides, which can be directly used for probability-based evaluation in subsequent processing steps. Our experiments indicate that BPDA2d outperforms state-of-the-art detection methods on both simulated data and real liquid chromatography–mass spectrometry data, according to sensitivity and detection accuracy. Availability: The BPDA2d software package is available at http://gsp.tamu.edu/Publications/supplementary/sun11a/ Contact: Michelle.Zhang@utsa.edu ; edward@ece.tamu.edu Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 13
    Publication Date: 2012-02-17
    Description: Motivation: The continued progress in developing technological platforms, availability of many published experimental datasets, as well as different statistical methods to analyze those data have allowed approaching the same research question using various methods simultaneously. To get the best out of all these alternatives, we need to integrate their results in an unbiased manner. Prioritized gene lists are a common result presentation method in genomic data analysis applications. Thus, the rank aggregation methods can become a useful and general solution for the integration task. Results: Standard rank aggregation methods are often ill-suited for biological settings where the gene lists are inherently noisy. As a remedy, we propose a novel robust rank aggregation (RRA) method. Our method detects genes that are ranked consistently better than expected under null hypothesis of uncorrelated inputs and assigns a significance score for each gene. The underlying probabilistic model makes the algorithm parameter free and robust to outliers, noise and errors. Significance scores also provide a rigorous way to keep only the statistically relevant genes in the final list. These properties make our approach robust and compelling for many settings. Availability: All the methods are implemented as a GNU R package R obust R ank A ggreg , freely available at the Comprehensive R Archive Network http://cran.r-project.org/ . Contact: vilo@ut.ee Supplementary information Supplementary data are available at Bioinformatics online.
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  • 14
    Publication Date: 2012-02-17
    Description: : CLARE is a computational method designed to reveal sequence encryption of tissue-specific regulatory elements. Starting with a set of regulatory elements known to be active in a particular tissue/process, it learns the sequence code of the input set and builds a predictive model from features specific to those elements. The resulting model can then be applied to user-supplied genomic regions to identify novel candidate regulatory elements. CLARE's model also provides a detailed analysis of transcription factors that most likely bind to the elements, making it an invaluable tool for understanding mechanisms of tissue-specific gene regulation. Availability: CLARE is freely accessible at http://clare.dcode.org/ . Contact: taherl@ncbi.nlm.nih.gov ; ovcharen@nih.gov Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 15
    Publication Date: 2012-02-17
    Description: Motivation: We present a pipeline for the pre-processing, quality assessment, read distribution and methylation estimation for methylated DNA immunoprecipitation (MeDIP)-sequence datasets. This is the first MeDIP-seq-specific analytic pipeline that starts at the output of the sequencers. This pipeline will reduce the data analysis load on staff and allows the easy and straightforward analysis of sequencing data for DNA methylation. The pipeline integrates customized scripting and several existing tools, which can deal with both paired and single end data. Availability: The package and extensive documentation, and comparison to public data is available at http://life.tongji.edu.cn/meqa/ Contact: jhuang@cephb.fr
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  • 16
    Publication Date: 2012-02-17
    Description: Motivation: A plethora of bioinformatics analysis has led to the discovery of numerous gene sets, which can be interpreted as discrete measurements emitted from latent signaling pathways. Their potential to infer signaling pathway structures, however, has not been sufficiently exploited. Existing methods accommodating discrete data do not explicitly consider signal cascading mechanisms that characterize a signaling pathway. Novel computational methods are thus needed to fully utilize gene sets and broaden the scope from focusing only on pairwise interactions to the more general cascading events in the inference of signaling pathway structures. Results: We propose a gene set based simulated annealing (SA) algorithm for the reconstruction of signaling pathway structures. A signaling pathway structure is a directed graph containing up to a few hundred nodes and many overlapping signal cascades, where each cascade represents a chain of molecular interactions from the cell surface to the nucleus. Gene sets in our context refer to discrete sets of genes participating in signal cascades, the basic building blocks of a signaling pathway, with no prior information about gene orderings in the cascades. From a compendium of gene sets related to a pathway, SA aims to search for signal cascades that characterize the optimal signaling pathway structure. In the search process, the extent of overlap among signal cascades is used to measure the optimality of a structure. Throughout, we treat gene sets as random samples from a first-order Markov chain model. We evaluated the performance of SA in three case studies. In the first study conducted on 83 KEGG pathways, SA demonstrated a significantly better performance than Bayesian network methods. Since both SA and Bayesian network methods accommodate discrete data, use a ‘search and score’ network learning strategy and output a directed network, they can be compared in terms of performance and computational time. In the second study, we compared SA and Bayesian network methods using four benchmark datasets from DREAM. In our final study, we showcased two context-specific signaling pathways activated in breast cancer. Availibility: Source codes are available from http://dl.dropbox.com/u/16000775/sa_sc.zip Contact: dzhu@wayne.edu Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 17
    Publication Date: 2012-02-17
    Description: : We provide a Bioconductor package with quality assessment, processing and visualization tools for high-throughput sequencing data, with emphasis in ChIP-seq and RNA-seq studies. It includes detection of outliers and biases, inefficient immuno-precipitation and overamplification artifacts, de novo identification of read-rich genomic regions and visualization of the location and coverage of genomic region lists. Availability: www.bioconductor.org Contact: david.rossell@irbbarcelona.org Supplementary information: Supplementary data available at Bioinformatics online.
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  • 18
    Publication Date: 2012-02-17
    Description: Motivation: We study a stochastic method for approximating the set of local minima in partial RNA folding landscapes associated with a bounded-distance neighbourhood of folding conformations. The conformations are limited to RNA secondary structures without pseudoknots. The method aims at exploring partial energy landscapes p L induced by folding simulations and their underlying neighbourhood relations. It combines an approximation of the number of local optima devised by Garnier and Kallel (2002) with a run-time estimation for identifying sets of local optima established by Reeves and Eremeev (2004). Results: The method is tested on nine sequences of length between 50 nt and 400 nt, which allows us to compare the results with data generated by RNAsubopt and subsequent barrier tree calculations. On the nine sequences, the method captures on average 92% of local minima with settings designed for a target of 95%. The run-time of the heuristic can be estimated by O ( n 2 D ln), where n is the sequence length, is the number of local minima in the partial landscape p L under consideration and D is the maximum number of steepest descent steps in attraction basins associated with p L . Contact: a.albrecht@qub.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 19
    Publication Date: 2012-02-17
    Description: Motivation: RNA-seq is a powerful technology for the study of transcriptome profiles that uses deep-sequencing technologies. Moreover, it may be used for cellular phenotyping and help establishing the etiology of diseases characterized by abnormal splicing patterns. In RNA-Seq, the exact nature of splicing events is buried in the reads that span exon–exon boundaries. The accurate and efficient mapping of these reads to the reference genome is a major challenge. Results: We developed PASSion, a pattern growth algorithm-based pipeline for splice site detection in paired-end RNA-Seq reads. Comparing the performance of PASSion to three existing RNA-Seq analysis pipelines, TopHat, MapSplice and HMMSplicer, revealed that PASSion is competitive with these packages. Moreover, the performance of PASSion is not affected by read length and coverage. It performs better than the other three approaches when detecting junctions in highly abundant transcripts. PASSion has the ability to detect junctions that do not have known splicing motifs, which cannot be found by the other tools. Of the two public RNA-Seq datasets, PASSion predicted ~ 137 000 and 173 000 splicing events, of which on average 82 are known junctions annotated in the Ensembl transcript database and 18% are novel. In addition, our package can discover differential and shared splicing patterns among multiple samples. Availability: The code and utilities can be freely downloaded from https://trac.nbic.nl/passion and ftp://ftp.sanger.ac.uk/pub/zn1/passion Contact: y.zhang@lumc.nl ; k.ye@lumc.nl Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 20
    Publication Date: 2012-02-17
    Description: Motivation: The completion of 168 genome sequences from a single population of Drosophila melanogaster provides a global view of genomic variation and an understanding of the evolutionary forces shaping the patterns of DNA polymorphism and divergence along the genome. Results: We present the ‘Population Drosophila Browser’ (PopDrowser), a new genome browser specially designed for the automatic analysis and representation of genetic variation across the D. melanogaster genome sequence. PopDrowser allows estimating and visualizing the values of a number of DNA polymorphism and divergence summary statistics, linkage disequilibrium parameters and several neutrality tests. PopDrowser also allows performing custom analyses on-the-fly using user-selected parameters. Availability: PopDrowser is freely available from http://PopDrowser.uab.cat . Contact: miquel.ramia@uab.cat
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  • 21
    Publication Date: 2012-02-17
    Description: Motivation: Probabilistic approaches for inferring transcription factor binding sites (TFBSs) and regulatory motifs from DNA sequences have been developed for over two decades. Previous work has shown that prediction accuracy can be significantly improved by incorporating features such as the competition of multiple transcription factors (TFs) for binding to nearby sites, the tendency of TFBSs for co-regulated TFs to cluster and form cis -regulatory modules and explicit evolutionary modeling of conservation of TFBSs across orthologous sequences. However, currently available tools only incorporate some of these features, and significant methodological hurdles hampered their synthesis into a single consistent probabilistic framework. Results: We present MotEvo, a integrated suite of Bayesian probabilistic methods for the prediction of TFBSs and inference of regulatory motifs from multiple alignments of phylogenetically related DNA sequences, which incorporates all features just mentioned. In addition, MotEvo incorporates a novel model for detecting unknown functional elements that are under evolutionary constraint, and a new robust model for treating gain and loss of TFBSs along a phylogeny. Rigorous benchmarking tests on ChIP-seq datasets show that MotEvo's novel features significantly improve the accuracy of TFBS prediction, motif inference and enhancer prediction. Availability: Source code, a user manual and files with several example applications are available at www.swissregulon.unibas.ch . Contact: erik.vannimwegen@unibas.ch Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 22
    Publication Date: 2012-02-17
    Description: : We present LaTcOm, a new web tool, which offers several alternative methods for ‘rare codon cluster’ (RCC) identification from a single and simple graphical user interface. In the current version, three RCC detection schemes are implemented: the recently described %MinMax algorithm and a simplified sliding window approach, along with a novel modification of a linear-time algorithm for the detection of maximally scoring subsequences tailored to the RCC detection problem. Among a number of user tunable parameters, several codon-based scales relevant for RCC detection are available, including tRNA abundance values from Escherichia coli and several codon usage tables from a selection of genomes. Furthermore, useful scale transformations may be performed upon user request (e.g. linear, sigmoid). Users may choose to visualize RCC positions within the submitted sequences either with graphical representations or in textual form for further processing. Availability: LaTcOm is freely available online at the URL http://troodos.biol.ucy.ac.cy/latcom.html . Contact: vprobon@ucy.ac.cy Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 23
    Publication Date: 2012-02-17
    Description: : Many existing databases annotate experimentally characterized single nucleotide polymorphisms (SNPs). Each non-synonymous SNP (nsSNP) changes one amino acid in the gene product (single amino acid substitution;SAAS). This change can either affect protein function or be neutral in that respect. Most polymorphisms lack experimental annotation of their functional impact. Here, we introduce SNPdbe—SNP database of effects, with predictions of computationally annotated functional impacts of SNPs. Database entries represent nsSNPs in dbSNP and 1000 Genomes collection, as well as variants from UniProt and PMD. SAASs come from 〉2600 organisms; ‘human’ being the most prevalent. The impact of each SAAS on protein function is predicted using the SNAP and SIFT algorithms and augmented with experimentally derived function/structure information and disease associations from PMD, OMIM and UniProt. SNPdbe is consistently updated and easily augmented with new sources of information. The database is available as an MySQL dump and via a web front end that allows searches with any combination of organism names, sequences and mutation IDs. Availability: http://www.rostlab.org/services/snpdbe Contact: schaefer@rostlab.org ; snpdbe@rostlab.org
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  • 24
    Publication Date: 2012-02-17
    Description: : We have implemented in a single package all the features required for extracting, visualizing and manipulating fully conserved positions as well as those with a family-dependent conservation pattern in multiple sequence alignments. The program allows, among other things, to run different methods for extracting these positions, combine the results and visualize them in protein 3D structures and sequence spaces. Availability and implementation: JDet is a multiplatform application written in Java. It is freely available, including the source code, at http://csbg.cnb.csic.es/JDet . The package includes two of our recently developed programs for detecting functional positions in protein alignments ( Xdet and S3Det ), and support for other methods can be added as plug-ins. A help file and a guided tutorial for JDet are also available. Contact: pazos@cnb.csic.es
    Print ISSN: 1367-4803
    Electronic ISSN: 1460-2059
    Topics: Biology , Computer Science , Medicine
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  • 25
    Publication Date: 2012-02-17
    Description: : VarSifter is a graphical software tool for desktop computers that allows investigators of varying computational skills to easily and quickly sort, filter, and sift through sequence variation data. A variety of filters and a custom query framework allow filtering based on any combination of sample and annotation information. By simplifying visualization and analyses of exome-scale sequence variation data, this program will help bring the power and promise of massively-parallel DNA sequencing to a broader group of researchers. Availability and Implementation: VarSifter is written in Java, and is freely available in source and binary versions, along with a User Guide, at http://research.nhgri.nih.gov/software/VarSifter/ . Contact: mullikin@mail.nih.gov Supplementary Information: Additional figures and methods available online at the journal's website.
    Print ISSN: 1367-4803
    Electronic ISSN: 1460-2059
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  • 26
    Publication Date: 2012-12-26
    Description: by Ping-Ping Yao, Lei Qian, Yong Xia, Fang Xu, Zhang-Nv Yang, Rong-Hui Xie, Xiao Li, Wei-Feng Liang, Xiao-Xiao Huang, Zhi-Yong Zhu, Han-Ping Zhu A reliable disease model mimicking Enterovirus 71 (EV71) infection in humans is essential for understanding pathogenesis and for developing a safe and effective vaccine. Commonly used rodent models including mouse or rat models are not suitable for vaccine evaluation because the rodents are resistant to EV71 infection after they reach the age of 6 days. In this study, 21-day-old gerbils inoculated intraperitoneally (IP) with a non mouse-adapted EV71 strain developed neurological lesion-related signs including hind limb paralysis, slowness, ataxia and lethargy similar to those of central nervous system (CNS) infection of EV71 in humans. The infected gerbils eventually died of the neurological lesions and EV71 could be isolated from lung, liver, spleen, kidney, heart, spinal cord, brain cortex, brainstem and skeletal muscle. Significantly high virus replication was detected in spinal cord, brainstem and skeletal muscle by cellular analysis, real-time quantitative PCR (RT-PCR) and immunohistochemical staining. Histopathologic changes such as neuronal degeneration, neuronal loss and neuronophagia were observed in spinal cord, brain cortex, brainstem, and skeletal muscle along with necrotizing myositis and splenic atrophy. Gerbils that received two doses of inactive whole-virus vaccine showed no EV71-specific symptoms after challenged with EV71. In contrast, gerbils that received mock vaccination died of EV71-induced neuropathology after challenged with EV71. The result indicates that gerbils can serve as a reliable disease model for evaluating safety and efficacy of EV71 vaccine.
    Electronic ISSN: 1932-6203
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  • 27
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    In: PLoS ONE
    Publication Date: 2012-12-27
    Description: by Anna Ligasová, Dmytro Strunin, Radek Liboska, Ivan Rosenberg, Karel Koberna A new method of the light microscopy detection of BrdU-labeled DNA in situ is described. It is based on the oxidative attack at the deoxyribose moiety by copper(I) in the presence of oxygen, which leads to the abstraction of hydrogen atom from deoxyribose culminating in the elimination of the nucleobase, scission of the nucleic-acid strand and formation of frequent gaps. The gaps allow the reaction of the antibodies with the commonly used markers of replication (e.g. 5-bromo-2′-deoxyuridine), which are otherwise masked. The method developed makes it possible to detect nuclear and mitochondrial DNA replication efficiently. In most cases, it does not inhibit effective protein detections and in addition enables simultaneous localization of newly-synthesized RNA. The alternative presently-used methods result in protein denaturation and/or extensive DNA cleavage followed by the DNA-bound proteins peeling off.
    Electronic ISSN: 1932-6203
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  • 28
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    In: PLoS ONE
    Publication Date: 2012-12-27
    Description: by Francesca Collu, Matteo Ceccarelli, Paolo Ruggerone Ligand-receptor interactions are at the basis of the mediation of our physiological responses to a large variety of ligands, such as hormones, neurotransmitters and environmental stimulants, and their tuning represents the goal of a large variety of therapies. Several molecular details of these interactions are still largely unknown. In an effort to shed some light on this important issue, we performed a computational study on the interaction of two related compounds differing by a single methyl group (clozapine and desmethylclozapine) with a -opioid receptor. According to experiments, desmethylclozapine is more active than clozapine, providing a system well suited for a comparative study. We investigated stable configurations of the two drugs inside the receptor by simulating their escape routes by molecular dynamics simulations. Our results point out that the action of the compounds might be related to the spatial and temporal distribution of the affinity sites they visit during their permanency. Moreover, no particularly pronounced structural perturbations of the receptor were detected during the simulations, reinforcing the idea of a strong dynamical character of the interaction process, with an important role played by the solvent in addition.
    Electronic ISSN: 1932-6203
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  • 29
    Publication Date: 2012-12-27
    Description: by Qiang Feng, Xia Zou, Ling Lu, Yun Li, Yunzhang Liu, Jianfeng Zhou, Cunming Duan REDD1/redd1 is a stress-response gene that is induced under various stressful conditions such as hypoxia, DNA damage, and energy stress. The increased REDD1 inhibits mTOR signaling and cell growth. Here we report an unexpected role of Redd1 in regulating dorsoventral patterning in zebrafish embryos and the underlying mechanisms. Zebrafish redd1 mRNA is maternally deposited. Although it is ubiquitously detected in many adult tissues, its expression is highly tissue-specific and dynamic during early development. Hypoxia and heat shock strongly induce redd1 expression in zebrafish embryos. Knockdown of Redd1 using two independent morpholinos results in dorsalized embryos and this effect can be rescued by injecting redd1 mRNA. Forced expression of Redd1 ventralizes embryos. Co-expression of Redd1 with Wnt3a or a constitutively active form of β-catenin suggests that Redd1 alters dorsoventral patterning by antagonizing the Wnt/β-catenin signaling pathway. These findings have unraveled a novel role of Redd1 in early development by antagonizing Wnt/β-catenin signaling.
    Electronic ISSN: 1932-6203
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  • 30
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    In: PLoS ONE
    Publication Date: 2012-12-27
    Description: by Claudia Figueroa-Romero, Junguk Hur, Diane E. Bender, Colin E. Delaney, Michael D. Cataldo, Andrea L. Smith, Raymond Yung, Douglas M. Ruden, Brian C. Callaghan, Eva L. Feldman Amyotrophic lateral sclerosis (ALS) is a terminal disease involving the progressive degeneration of motor neurons within the motor cortex, brainstem and spinal cord. Most cases are sporadic (sALS) with unknown causes suggesting that the etiology of sALS may not be limited to the genotype of patients, but may be influenced by exposure to environmental factors. Alterations in epigenetic modifications are likely to play a role in disease onset and progression in ALS, as aberrant epigenetic patterns may be acquired throughout life. The aim of this study was to identify epigenetic marks associated with sALS. We hypothesize that epigenetic modifications may alter the expression of pathogenesis-related genes leading to the onset and progression of sALS. Using ELISA assays, we observed alterations in global methylation (5 mC) and hydroxymethylation (5 HmC) in postmortem sALS spinal cord but not in whole blood. Loci-specific differentially methylated and expressed genes in sALS spinal cord were identified by genome-wide 5mC and expression profiling using high-throughput microarrays. Concordant direction, hyper- or hypo-5mC with parallel changes in gene expression (under- or over-expression), was observed in 112 genes highly associated with biological functions related to immune and inflammation response. Furthermore, literature-based analysis identified potential associations among the epigenes. Integration of methylomics and transcriptomics data successfully revealed methylation changes in sALS spinal cord. This study represents an initial identification of epigenetic regulatory mechanisms in sALS which may improve our understanding of sALS pathogenesis for the identification of biomarkers and new therapeutic targets.
    Electronic ISSN: 1932-6203
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  • 31
    Publication Date: 2012-12-27
    Description: by Wen-Yang Tsai, Szu-Chia Hsieh, Chih-Yun Lai, Hong-En Lin, Vivek R. Nerurkar, Wei-Kung Wang Background The envelope (E) protein of dengue virus (DENV) is the major immunogen for dengue vaccine development. At the C-terminus are two α-helices (EH1 and EH2) and two transmembrane domains (ET1 and ET2). After synthesis, E protein forms a heterodimer with the precursor membrane (prM) protein, which has been shown as a chaperone for E protein and could prevent premature fusion of E protein during maturation. Recent reports of enhancement of DENV infectivity by anti-prM monoclonal antibodies (mAbs) suggest the presence of prM protein in dengue vaccine is potentially harmful. A better understanding of prM-E interaction and its effect on recognition of E and prM proteins by different antibodies would provide important information for future design of safe and effective subunit dengue vaccines. Methodology/Principal Findings In this study, we examined a series of C-terminal truncation constructs of DENV4 prME, E and prM. In the absence of E protein, prM protein expressed poorly. In the presence of E protein, the expression of prM protein increased in a dose-dependent manner. Radioimmunoprecipitation, sucrose gradient sedimentation and pulse-chase experiments revealed ET1 and EH2 were involved in prM-E interaction and EH2 in maintaining the stability of prM protein. Dot blot assay revealed E protein affected the recognition of prM protein by an anti-prM mAb; truncation of EH2 or EH1 affected the recognition of E protein by several anti-E mAbs, which was further verified by capture ELISA. The E protein ectodomain alone can be recognized well by all anti-E mAbs tested. Conclusions/Significance A C-terminal domain (EH2) of DENV E protein can affect the expression and stability of its chaperone prM protein. These findings not only add to our understanding of the interaction between prM and E proteins, but also suggest the ectodomain of E protein alone could be a potential subunit immunogen without inducing anti-prM response.
    Electronic ISSN: 1932-6203
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  • 32
    Publication Date: 2012-12-27
    Description: by Quancheng Zhou, Guihua Sheng The thermal decomposition of Perilla frutescens polysaccharide was examined by thermogravimetry, differential thermogravimetry, and differential thermal analysis. The results showed that the mass loss of the substance proceeded in three steps. The first stage can be attributed to the expulsion of the water from ambient temperature to 182°C. The second stage corresponded to devolatilization from 182°C to 439°C. The residue slowly degraded in the third stage. The weight loss in air is faster than that in nitrogen, because the oxygen in air accelerated the pyrolytic reaction speed reaction. The heating rate significantly affected the pyrolysis of the sample. Similar activation energies of the degradation process (210–211 kJ mol −1 ) were obtained by the FWO, KAS, and Popescu techniques. According to Popescu mechanism functions, the possible kinetic model was estimated to be Avrami–Erofeev 20 g ( α ) = [−ln(1– α )] 4 .
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  • 33
    Publication Date: 2012-12-27
    Description: by Linda Irvine, Donald W. Falconer, Claire Jones, Ian W. Ricketts, Brian Williams, Iain K. Crombie Background Process evaluation is essential in developing, piloting and evaluating complex interventions. This often involves observation of intervention delivery and interviews with study participants. Mobile telephone interventions involve no face to face contact, making conventional process evaluation difficult. This study assesses the utility of novel techniques for process evaluation involving no face to face contact. Methods Text messages were delivered to 34 disadvantaged men as part of a feasibility study of a brief alcohol intervention. Process evaluation focused on delivery of the text messages and responses received from study participants. The computerized delivery system captured data on receipt of the messages. The text messages, delivered over 28 days, included nine which asked questions. Responses to these questions served as one technique for process evaluation by ascertaining the nature of engagement with the study and with steps on the causal chain to behavior change. Results A total of 646 SMS text messages were sent to participants. Of these, 613 messages (95%) were recorded as delivered to participants’ telephones. 88% of participants responded to messages that asked questions. There was little attenuation in responses to the questions across the intervention period. Content analysis of the responses revealed that participants engaged with text messages, thought deeply about their content and provided carefully considered personal responses to the questions. Conclusions Socially disadvantaged men, a hard to reach population, engaged in a meaningful way over a sustained period with an interactive intervention delivered by text message. The novel process measures used in the study are unobtrusive, low cost and collect real-time data on all participants. They assessed the fidelity of delivery of the intervention and monitored retention in the study. They measured levels of engagement and identified participants’ reactions to components of the intervention. These methods provide a valuable addition to conventional process evaluation techniques.
    Electronic ISSN: 1932-6203
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  • 34
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    In: PLoS ONE
    Publication Date: 2012-12-27
    Description: by Golnar Karimian, Manon Buist-Homan, Bojana Mikus, Robert H. Henning, Klaas Nico Faber, Han Moshage Conclusion Angiotensin II protects hepatocytes from bile salt-induced apoptosis through a combined activation of PI3-kinase, MAPKs, PKC pathways and inhibition of bile salt-induced ER stress. Our results suggest a mechanism for the observed hepatocyte-toxicity of Sartans (angiotensin receptor blockers, ARBs) in some patients with chronic liver injury.
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  • 35
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    In: PLoS ONE
    Publication Date: 2012-12-27
    Description: by Nuria Kotecki, Nicolas Penel, Antoine Adenis, Charles Ferte, Stéphanie Clisant Background The diagnosis of tumour progression or progressive disease (PD) is a key element for designing and interpreting contemporary phase II trials. In some cases, PD is stated by the physician and is not formally confirmed by imaging. Purpose In this study, we intend to analyze the value of the PD based on clinical judgment and the risk of overestimating the occurrence of PD by clinical judgment. Methods We have conducted a single-centre retrospective study to analyse the diagnostic accuracy of this clinical judgment compared to planned imaging including all patients enrolled in our institution in phase II trials investigating systemic treatments for advanced solid tumours between January 2008 and November 2010. Results The positive predictive value (PPV) and the specificity of clinical judgment of PD was very high (〉90%). Conclusions According to this study, the clinical judgment of PD is highly predictive of radiological PD as assessed, for example, by RECIST. Physicians do not overestimate PD occurence. Clinical judgment of PD could be taken into account in the definition of PD.
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  • 36
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    In: PLoS ONE
    Publication Date: 2012-12-27
    Description: by Aziza El Harchi, Dario Melgari, Yi Hong Zhang, Henggui Zhang, Jules C. Hancox Background The familial Short QT Syndrome (SQTS) is associated with an increased risk of cardiac arrhythmia and sudden death. Gain-of-function mutations in the hERG K + channel protein have been linked to variant 1 of the SQTS. A hERG channel pore (T618I) mutation has recently been identified in families with heritable SQTS. This study aimed to determine effects of the T618I-hERG mutation on (i) hERG current (I hERG ) elicited by ventricular action potentials; (ii) the sensitivity of I hERG to inhibition by four clinically used antiarrhythmic drugs. Methods Electrophysiological recordings of I hERG were made at 37°C from HEK 293 cells expressing wild-type (WT) or T618I hERG. Whole-cell patch clamp recording was performed using both conventional voltage clamp and ventricular action potential (AP) clamp methods. Results Under conventional voltage-clamp, WT I hERG peaked at 0-+10 mV, whilst for T618I I hERG maximal current was right-ward shifted to ∼ +40 mV. Voltage-dependent activation and inactivation of T618I I hERG were positively shifted (respectively by +15 and ∼ +25 mV) compared to WT I hERG . The I hERG ‘window’ was increased for T618I compared to WT hERG. Under ventricular AP clamp, maximal repolarising WT I hERG occurred at ∼ -30 mV, whilst for T618I hERG peak I hERG occurred earlier during AP repolarisation, at ∼ +5 mV. Under conventional voltage clamp, half-maximal inhibitory concentrations (IC 50 ) for inhibition of I hERG tails by quinidine, disopyramide, D-sotalol and flecainide for T618I hERG ranged between 1.4 and 3.2 fold that for WT hERG. Under action potential voltage clamp, T618I IC 50 s ranged from 1.2 to 2.0 fold the corresponding IC 50 values for WT hERG. Conclusions The T618I mutation produces a more modest effect on repolarising I hERG than reported previously for the N588K-hERG variant 1 SQTS mutation. All drugs studied here appear substantially to retain their ability to inhibit I hERG in the setting of the SQTS-linked T618I mutation.
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  • 37
    Publication Date: 2012-12-27
    Description: by Adelene Ai-Lian Song, Janna Ong Abdullah, Mohd. Puad Abdullah, Norazizah Shafee, Roohaida Othman, Ee-Fun Tan, Normah Mohd. Noor, Abdul Rahim Raha Isoprenoids are a large and diverse group of metabolites with interesting properties such as flavour, fragrance and therapeutic properties. They are produced via two pathways, the mevalonate pathway or the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway. While plants are the richest source of isoprenoids, they are not the most efficient producers. Escherichia coli and yeasts have been extensively studied as heterologous hosts for plant isoprenoids production. In the current study, we describe the usage of the food grade Lactococcus lactis as a potential heterologous host for the production of sesquiterpenes from a local herbaceous Malaysian plant, Persicaria minor (synonym Polygonum minus ). A sesquiterpene synthase gene from P. minor was successfully cloned and expressed in L. lactis . The expressed protein was identified to be a β-sesquiphellandrene synthase as it was demonstrated to be functional in producing β-sesquiphellandrene at 85.4% of the total sesquiterpenes produced based on in vitro enzymatic assays. The recombinant L. lactis strain developed in this study was also capable of producing β-sesquiphellandrene in vivo without exogenous substrates supplementation. In addition, overexpression of the strain’s endogenous 3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMGR), an established rate-limiting enzyme in the eukaryotic mevalonate pathway, increased the production level of β-sesquiphellandrene by 1.25–1.60 fold. The highest amount achieved was 33 nM at 2 h post-induction.
    Electronic ISSN: 1932-6203
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  • 38
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    In: PLoS ONE
    Publication Date: 2012-12-27
    Description: by Larisa R. G. DeSantis, Blaine W. Schubert, Jessica R. Scott, Peter S. Ungar The saber-toothed cat, Smilodon fatalis , and American lion, Panthera atrox , were among the largest terrestrial carnivores that lived during the Pleistocene, going extinct along with other megafauna ∼12,000 years ago. Previous work suggests that times were difficult at La Brea (California) during the late Pleistocene, as nearly all carnivores have greater incidences of tooth breakage (used to infer greater carcass utilization) compared to today. As Dental Microwear Texture Analysis (DMTA) can differentiate between levels of bone consumption in extant carnivores, we use DMTA to clarify the dietary niches of extinct carnivorans from La Brea. Specifically, we test the hypothesis that times were tough at La Brea with carnivorous taxa utilizing more of the carcasses. Our results show no evidence of bone crushing by P. atrox , with DMTA attributes most similar to the extant cheetah, Acinonyx jubatus , which actively avoids bone. In contrast, S. fatalis has DMTA attributes most similar to the African lion Panthera leo , implying that S. fatalis did not avoid bone to the extent previously suggested by SEM microwear data. DMTA characters most indicative of bone consumption (i.e., complexity and textural fill volume) suggest that carcass utilization by the extinct carnivorans was not necessarily more complete during the Pleistocene at La Brea; thus, times may not have been “tougher” than the present. Additionally, minor to no significant differences in DMTA attributes from older (∼30–35 Ka) to younger (∼11.5 Ka) deposits offer little evidence that declining prey resources were a primary cause of extinction for these large cats.
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  • 39
    Publication Date: 2012-12-27
    Description: by Feng Qu, Cai-Sheng Wu, Jin-Feng Hou, Ying Jin, Jin-Lan Zhang Background Hypersensitivity diseases are associated with many severe human illnesses, including leprosy and tuberculosis. Emerging evidence suggests that the pathogenesis and pathological mechanisms of treating these diseases may be attributable to sphingolipid metabolism. Methods High performance liquid chromatography-tandem mass spectrometry was employed to target and measure 43 core sphingolipids in the plasma, kidneys, livers and spleens of BALB/c mice from four experimental groups: control, delayed-type hypersensitivity (DTH) model, DTH+triptolide, and control+triptolide. Orthogonal partial least squares discriminant analysis (OPLS-DA) was used to identify potential biomarkers associated with variance between groups. Relationships between the identified biomarkers and disease markers were evaluated by Spearman correlation. Results As a treatment to hypersensitivity disease, triptolide significantly inhibit the ear swelling and recover the reduction of splenic index caused by DTH. The sphingolipidomic result revealed marked alterations in sphingolipid levels between groups that were associated with the effects of the disease and triptolide treatment. Based on this data, 23 potential biomarkers were identified by OPLS-DA, and seven of these biomarkers correlated markedly with the disease markers (p
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  • 40
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    Oxford University Press
    Publication Date: 2012-12-28
    Print ISSN: 0959-6658
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  • 41
    Publication Date: 2012-12-28
    Description: Insect cells are widely used for recombinant glycoprotein production, but they cannot provide the glycosylation patterns required for some biotechnological applications. This problem has been addressed by genetically engineering insect cells to express mammalian genes encoding various glycoprotein glycan processing functions. However, for various reasons, the impact of a mammalian cytosine-5'-monophospho (CMP)-sialic acid transporter has not yet been examined. Thus, we transformed Spodoptera frugiperda (Sf9) cells with six mammalian genes to generate a new cell line, SfSWT-4, that can produce sialylated glycoproteins when cultured with the sialic acid precursor, N -acetylmannosamine. We then super-transformed SfSWT-4 with a human CMP-sialic acid transporter (hCSAT) gene to isolate a daughter cell line, SfSWT-6, which expressed the hCSAT gene in addition to the other mammalian glycogenes. SfSWT-6 cells had higher levels of cell surface sialylation and also supported higher levels of recombinant glycoprotein sialylation, particularly when cultured with low concentrations of N -acetylmannosamine. Thus, hCSAT expression has an impact on glycoprotein sialylation, can reduce the cost of recombinant glycoprotein production and therefore should be included in ongoing efforts to glycoengineer the baculovirus-insect cell system. The results of this study also contributed new insights into the endogenous mechanism and potential mechanisms of CMP-sialic acid accumulation in the Golgi apparatus of lepidopteran insect cells.
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  • 42
    Publication Date: 2012-12-28
    Description: Chondroitin sulfate (CS) chains regulate the development of the central nervous system in vertebrates and are linear polysaccharides consisting of variously sulfated repeating disaccharides, [–4GlcUAβ1-3GalNAcβ1–] n , where GlcUA and GalNAc represent d -glucuronic acid and N -acetyl- d -galactosamine, respectively. CS chains containing D-disaccharide units [GlcUA(2- O -sulfate)-GalNAc(6- O -sulfate)] are involved in the development of cerebellar Purkinje cells and neurite outgrowth-promoting activity through interaction with a neurotrophic factor, pleiotrophin, resulting in the regulation of signaling. In this study, to obtain further structural information on the CS chains containing d -disaccharide units involved in brain development, oligosaccharides containing D-units were isolated from a shark fin cartilage. Seven novel hexasaccharide sequences, O-D-D, A-D-D, C-D-D, E-A-D, D-D-C, E-D-D and A-B-D, in addition to three previously reported sequences, C-A-D, C-D-C and A-D-A, were isolated from a CS preparation of shark fin cartilage after exhaustive digestion with chondroitinase AC-I, which cannot act on the galactosaminidic linkages bound to D-units. The symbol stands for a 4,5-unsaturated bond of uronic acids, whereas A, B, C, D, E and O represent [GlcUA-GalNAc(4- O -sulfate)], [GlcUA(2- O -sulfate)-GalNAc(4- O -sulfate)], [GlcUA-GalNAc(6- O -sulfate)], [GlcUA(2- O -sulfate)-GalNAc(6- O -sulfate)], [GlcUA-GalNAc(4- O -, 6- O -sulfate)] and [GlcUA-GalNAc], respectively. In binding studies using an anti-CS monoclonal antibody, MO-225, the epitopes of which are involved in cerebellar development in mammals, novel epitope structures, A-D-A, A-D-D and A-B-D, were revealed. Hexasaccharides containing two consecutive D-units or a B-unit will be useful for the structural and functional analyses of CS chains particularly in the neuroglycobiological fields.
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  • 43
    Publication Date: 2012-12-28
    Description: Protein O -fucosyltransferase 1 (Pofut1) and protein O -fucosyltransferase 2 (Pofut2) add O -linked fucose at distinct consensus sequences in properly folded epidermal growth factor (EGF)-like repeats and thrombospondin type-1 (TSR) repeats, respectively. Glycan chain elongation past O -fucose can occur to yield a tetrasaccharide on EGF repeats and a disaccharide on TSRs. Elimination of Pofut1 in mice causes embryonic lethality with Notch-like phenotypes demonstrating that O -fucosylation of Notch is essential for its function. Similarly, elimination of Pofut2 results in an early embryonic lethal phenotype in mice, although the molecular mechanism for the lethality is unknown. The recent development of sugar analogs has revolutionized the study of glycans by providing a convenient method for labeling and tracking glycosylation. In order to study O -fucosylation, we took advantage of the recently developed reporter, 6-alkynyl fucose. Using the Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC), or "click" reaction, azido-biotin allows tagging and detection of 6AF-modified proteins. Here we examine whether proteins containing EGF repeats or TSRs with O -fucose consensus sequences are specifically modified with 6AF in cell culture. Using mass spectrometry (MS), we demonstrate that 6AF is efficiently incorporated onto the appropriate consensus sequences on EGF repeats and TSRs. Furthermore, the elongation of the O -fucose monosaccharide on EGF repeats and TSRs is not hampered when 6AF is used. These results show that 6AF is efficiently utilized in a truly bioorthogonal manner by Pofut1, Pofut2 and the enzymes that elongate O -fucose, providing evidence that 6AF is a significant new tool in the study of protein O -fucosylation.
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  • 44
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    Publication Date: 2012-12-28
    Description: Xanthan is a polysaccharide secreted by Xanthomonas campestris that contains pentameric repeat units. The biosynthesis of xanthan involves an operon composed of 12 genes ( gumB to gumM ). In this study, we analyzed the proteins encoded by gumB and gumC . Membrane fractionation showed that GumB was mainly associated with the outer membrane, whereas GumC was an inner membrane protein. By in silico analysis and specific globomycin inhibition, GumB was characterized as a lipoprotein. By reporter enzyme assays, GumC was shown to contain two transmembrane segments flanking a large periplasmic domain. We confirmed that gumB and gumC mutant strains uncoupled the synthesis of the lipid-linked repeat unit from the polymerization process. We studied the effects of gumB and gumC gene amplification on the production, composition and viscosity of xanthan. Overexpression of GumB, GumC or GumB and GumC simultaneously did not affect the total amount or the chemical composition of the polymer. GumB overexpression did not affect xanthan viscosity; however, a moderate increase in xanthan viscosity was achieved when GumC protein levels were increased 5-fold. Partial degradation of GumC was observed when only that protein was overexpressed; but co-expression of GumB and GumC diminished GumC degradation and resulted in higher xanthan viscosity than individual GumB or GumC overexpression. Compared with xanthan from the wild-type strain, longer polymer chains from the strain that simultaneously overexpressed GumB and GumC were observed by atomic force microscopy. Our results suggest that GumB–GumC protein levels modulate xanthan chain length, which results in altered polymer viscosity.
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  • 46
    Publication Date: 2012-12-28
    Description: Bifidobacterium bifidum is one of the most frequently found bifidobacteria in the intestines of newborn infants. We previously reported that B. bifidum possesses unique metabolic pathways for O -linked glycans on gastrointestinal mucin (Yoshida E, Sakurama H, Kiyohara M, Nakajima M, Kitaoka M, Ashida H, Hirose J, Katayama T, Yamamoto K, Kumagai H. 2012. Bifidobacterium longum subsp. infantis uses two different β-galactosidases for selectively degrading type-1 and type-2 human milk oligosaccharides. Glycobiology . 22:361–368). The nonreducing termini of O -linked glycans on mucin are frequently covered with histo-blood group antigens. Here, we identified a gene agabb from B. bifidum JCM 1254, which encodes glycoside hydrolase (GH) family 110 α-galactosidase. AgaBb is a 1289-amino acid polypeptide containing an N-terminal signal sequence, a GH110 domain, a carbohydrate-binding module (CBM) 51 domain, a bacterial Ig-like (Big) 2 domain and a C-terminal transmembrane region, in this order. The recombinant enzyme expressed in Escherichia coli hydrolyzed α1,3-linked Gal in branched blood group B antigen [Galα1-3(Fucα1-2)Galβ1-R], but not in a linear xenotransplantation antigen (Galα1-3Galβ1-R). The enzyme also acted on group B human salivary mucin and erythrocytes. We also revealed that CBM51 specifically bound blood group B antigen using both isothermal titration calorimetry and a solid-phase binding assay, and it enhanced the affinity of the enzyme toward substrates with multivalent B antigens. We suggest that this enzyme plays an important role in degrading B antigens to acquire nutrients from mucin oligosaccharides in the gastrointestinal tracts.
    Print ISSN: 0959-6658
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  • 47
    Publication Date: 2012-12-28
    Description: Alg3 of Saccharomyces cerevisiae catalyzes the mannosyl transfer from Man-P-Dol to Man 5 GlcNAc 2 -PP-Dol resulting in the formation of Man 6 GlcNAc 2 -PP-Dol, which is then further processed to the final precursor oligosaccharide Glc 3 Man 9 GlcNAc 2 for N-glycosylation of proteins. Here, we identified the alg3 gene of the mushroom-forming fungus Schizophyllum commune by homology search. Its function was confirmed by the complementation of the alg3 strain of S. cerevisiae . Inactivation of alg3 in S. commune resulted in the production of predominantly Man 3 GlcNAc 2 protein-linked N -glycans. No impact on growth nor a developmental phenotype due to the deletion was observed. This provides a first step toward engineering of a homogeneous, humanized N-glycosylation pattern for the production of therapeutic glycoproteins in mushrooms.
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  • 48
    Publication Date: 2012-12-28
    Description: We previously demonstrated that Siglec-15, a member of the Siglec family of glycan-recognition proteins, is expressed on a subset of macrophages and preferentially recognizes the sialyl-Tn (sTn) antigen, a tumor-associated glycan structure. In this study, we report on the biological significance of the Siglec-15-mediated interaction between monocytes/macrophages and cancer cells. Siglec-15 is expressed on tumor-associated macrophages (TAMs) in various human tumor tissues. We further demonstrated that its expression is substantially elevated in macrophage colony-stimulating factor-induced M2-like macrophages, which produced more transforming growth factor-β (TGF-β) in response to sTn-positive cells than to negative cells. We designed a co-culture model of THP-1 (human monocytic leukemia) cells and H157 (human lung carcinoma) cells mimicking the interaction between monocytes/macrophages and cancer cells that recapitulated the enhanced TGF-β production in Siglec-15 expressing THP-1 cells by the cellular interaction with sTn expressing H157 cells. The enhanced TGF-β production required a direct interaction between the two cell lines through sialic acids. Siglec-15 associates with adaptor protein DNAX activation protein of 12 kDa (DAP12) at the binding determinant Lys 274 in the transmembrane domain and transduces a signal to spleen tyrosine kinase (Syk). The enhanced TGF-β secretion was significantly attenuated by Syk inhibitor treatment of THP-1 cells or by substitution of the Siglec-15 Lys 274 to Ala, which disrupts the molecular interaction between Siglec15 and DAP12. These findings indicate that Siglec-15 recognizes the tumoral sTn antigen and transduces a signal for enhanced TGF-β secretion in TAMs and further suggest that Siglec-15 on macrophages may contribute to tumor progression by the TGF-β-mediated modulation of intratumoral microenvironments.
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  • 49
    Publication Date: 2012-12-28
    Print ISSN: 0959-6658
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  • 50
    Publication Date: 2012-12-29
    Description: by Thomas D. Pfister, Melinda Hollingshead, Robert J. Kinders, Yiping Zhang, Yvonne A. Evrard, Jiuping Ji, Sonny A. Khin, Suzanne Borgel, Howard Stotler, John Carter, Raymond Divelbiss, Shivaani Kummar, Yves Pommier, Ralph E. Parchment, Joseph E. Tomaszewski, James H. Doroshow Background Topoisomerase I (Top1) is a proven target for cancer therapeutics. Recent data from the Fluorouracil, Oxaliplatin, CPT-11: Use and Sequencing (FOCUS) trial demonstrated that nuclear staining of Top1 correlates with chemotherapeutic efficacy. Such a correlation may help identify patients likely to respond to Top1 inhibitors and illuminate their mechanism of action. Cellular response to Top1 inhibitors is complex, but Top1 target engagement is a necessary first step in this process. This paper reports the development and validation of a quantitative immunoassay for Top1 in tumors. Methodology/Principal Findings We have developed and validated a two-site enzyme chemiluminescent immunoassay for quantifying Top1 levels in tumor biopsies. Analytical validation of the assay established the inter-day coefficient of variation at 9.3%±3.4% and a 96.5%±7.3% assay accuracy. Preclinical fit-for-purpose modeling of topotecan time- and dose-effects was performed using topotecan-responsive and -nonresponsive xenografts in athymic nude mice. Higher baseline levels of Top1 were observed in topotecan-responsive than -nonresponsive tumors. Top1 levels reached a maximal decrease 4 to 7 hours following treatment of engrafted mice with topotecan and the indenoisoquinoline NSC 724998. Conclusions/Significance Our analysis of Top1 levels in control and treated tumors supports the previously proposed mechanism of action for Top1 inhibitor efficacy, wherein higher baseline Top1 levels lead to formation of more covalent-complex-dependent double-strand break damage and, ultimately, cell death. In contrast, xenografts with lower baseline Top1 levels accumulate fewer double-stand breaks, and may be more resistant to Top1 inhibitors. Our results support further investigation into the use of Top1 levels in tumors as a potential predictive biomarker. The Top1 immunoassay described in this paper has been incorporated into a Phase I clinical trial at the National Cancer Institute to assess pharmacodynamic response in tumor biopsies and determine whether baseline Top1 levels are predictive of response to indenoisoquinoline Top1 inhibitors.
    Electronic ISSN: 1932-6203
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  • 51
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    Public Library of Science (PLoS)
    In: PLoS ONE
    Publication Date: 2012-12-29
    Description: by Lindsay Riley, Hua Zhou, Kenneth Lange, Janet S. Sinsheimer, Mary E Sehl Introduction Trastuzumab dramatically improves survival in breast cancer patients whose tumor overexpresses HER2. A subpopulation of cells in human breast tumors has been identified with characteristics of cancer stem cells. These breast cancer stem-like cells (BCSCs) rely on HER2 signaling for self-renewal, suggesting that HER2-targeted therapy targets BCSCs even when the bulk of the tumor does not overexpress HER2. In order to guide clinical trials examining HER2-targeted therapy in the adjuvant setting, we propose a mathematical model to examine BCSC population dynamics and predict optimal duration of therapy. Methods Varying the susceptibility of BCSCs to HER2-targeted therapy, we quantify the average time to extinction of BCSCs. We expand our model using stochastic simulation to include the partially differentiated tumor cells (TCs) that represent bulk tumor population and examine effects of plasticity on required duration of therapy. Results Lower susceptibility of BCSCs and increased rates of dedifferentiation entail longer extinction times, indicating a need for prolonged administration of HER2-targeted therapy. We predict that even when therapy does not appreciably reduce tumor size in the advanced cancer setting, it will eventually eradicate the tumor in the adjuvant setting as long as there is at least a modest effect on BCSCs. Conclusions We anticipate that our results will inform clinical trials of targeted therapies in planning the duration of therapy needed to eradicate BCSCs. Our predictions also address safety, as longer duration of therapy entails a greater potential impact on normal stem cells that may also be susceptible to stem cell-targeted therapies.
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  • 52
    Publication Date: 2012-12-29
    Description: by Mahir Karakas, Jens Baumert, Marcus E. Kleber, Barbara Thorand, Dhayana Dallmeier, Günther Silbernagel, Tanja B. Grammer, Wolfgang Rottbauer, Christa Meisinger, Thomas Illig, Winfried März, Wolfgang Koenig Background Elevated soluble (s) E-selectin levels have been associated with various cardiovascular diseases. Recently, genetic variants in the ABO blood group have been related to E-selectin levels in a small cohort of patients with type 1 diabetes. We evaluated whether this association is reproducible in two large samples of Caucasians. Methodology/ Principal Findings Data of the present study was drawn from the population-based MONICA/KORA Augsburg study (n = 1,482) and the patients-based LURIC study (n = 1,546). A high-density genotyping array (50K IBC Chip) containing single-nucleotide polymorphisms (SNPs) from E-selectin candidate genes selected on known biology of E-selectin metabolism, mouse genetic studies, and human genetic association studies, was used for genotyping. Linear regression analyses with adjustment for age and sex (and survey in KORA) were applied to assess associations between gene variants and sE-selectin concentrations. A number of 12 SNPs (in KORA) and 13 SNPs (in LURIC), all from the ABO blood group gene, were significantly associated with the log-transformed concentration of E-selectin. The strongest association was observed for rs651007 with a change of log-transformed sE-selectin per one copy of the minor allele of −0.37 ng/ml (p = 1.87×10 −103 ) in KORA and −0.35 ng/ml (p = 5.11×10 −84 ) in LURIC. Inclusion of rs651007 increased the explained sE-selectin variance by 0.256 in KORA and 0.213 in LURIC. All SNPs had minor allele frequencies above 20% showing a substantial gene variation. Conclusions/ Significance Our findings in two independent samples indicate that the genetic variants at the ABO locus affect sE-selectin levels. Since distinct genome-wide association studies linked the ABO gene with myocardial infarction (MI) in the presence of coronary atherosclerosis and with coronary artery disease, these findings may not only enhance our understanding of adhesion molecule biology, but may also provide a focus for several novel research avenues.
    Electronic ISSN: 1932-6203
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  • 53
    Publication Date: 2012-12-29
    Description: by Hon-Yi Shi, Hao-Hsien Lee, Jinn-Tsong Tsai, Wen-Hsien Ho, Chieh-Fan Chen, King-Teh Lee, Chong-Chi Chiu Background Few studies of laparoscopic cholecystectomy (LC) outcome have used longitudinal data for more than two years. Moreover, no studies have considered group differences in factors other than outcome such as age and nonsurgical treatment. Additionally, almost all published articles agree that the essential issue of the internal validity (reproducibility) of the artificial neural network (ANN), support vector machine (SVM), Gaussian process regression (GPR) and multiple linear regression (MLR) models has not been adequately addressed. This study proposed to validate the use of these models for predicting quality of life (QOL) after LC and to compare the predictive capability of ANNs with that of SVM, GPR and MLR. Methodology/Principal Findings A total of 400 LC patients completed the SF-36 and the Gastrointestinal Quality of Life Index at baseline and at 2 years postoperatively. The criteria for evaluating the accuracy of the system models were mean square error (MSE) and mean absolute percentage error (MAPE). A global sensitivity analysis was also performed to assess the relative significance of input parameters in the system model and to rank the variables in order of importance. Compared to SVM, GPR and MLR models, the ANN model generally had smaller MSE and MAPE values in the training data set and test data set. Most ANN models had MAPE values ranging from 4.20% to 8.60%, and most had high prediction accuracy. The global sensitivity analysis also showed that preoperative functional status was the best parameter for predicting QOL after LC. Conclusions/Significance Compared with SVM, GPR and MLR models, the ANN model in this study was more accurate in predicting patient-reported QOL and had higher overall performance indices. Further studies of this model may consider the effect of a more detailed database that includes complications and clinical examination findings as well as more detailed outcome data.
    Electronic ISSN: 1932-6203
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  • 54
    Publication Date: 2012-12-29
    Description: by Stacie L. Lambert, Chin-Fen Yang, Zheng Liu, Rosemary Sweetwood, Jackie Zhao, Lily Cheng, Hong Jin, Jennifer Woo Background Toll-like receptor (TLR)4 agonists are known potent immunostimulatory compounds. These compounds can be formulated as part of novel adjuvants to enhance vaccine medicated immune responses. However, the contribution of the formulation to the innate in vivo activity of TLR4 agonist compounds is not well understood. Methodology and Principal Findings We evaluated synthetic TLR4 agonist Glucopyranosyl Lipid A (GLA) for its effects on molecular and cellular innate immune responses in the murine model. Microarray techniques were used to compare the responses to GLA in an aqueous formulation or in an oil-in-water Stable Emulsion formulation (GLA-SE) versus either SE alone or the mineral salt aluminum hydroxide (alum) at the muscle injection site over multiple timepoints. In contrast to the minimal gene upregulation induced by SE and alum, both GLA and GLA-SE triggered MyD88- and TRIF-dependent gene expression. Genes for chemokines, cytokine receptors, signaling molecules, complement, and antigen presentation were also strongly upregulated by GLA and GLA-SE. These included chemokines for T H 1-type T cells (CXCL9 and CXCL10) and mononuclear leukocytes (CCL2, CCL3) among others. GLA-SE induced stronger and more sustained gene upregulation than GLA in the muscle; GLA-SE induced genes were also detected in local draining lymph nodes and at lower levels in peripheral blood. Both GLA and GLA-SE resulted in increased cellular trafficking to the draining lymph nodes and upregulated MHC molecules and ICAM1 on local dendritic cells. GLA and GLA-SE transiently upregulated circulating MCP-1, TNFα, IFNγ and IP-10 in blood. Conclusions/Significance While GLA and GLA-SE activate a large number of shared innate genes and proteins, GLA-SE induces a quantitatively and qualitatively stronger response than GLA, SE or alum. The genes and proteins upregulated could be used to facilitate selection of appropriate adjuvant doses in vaccine formulations.
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  • 55
    Publication Date: 2012-12-29
    Description: by Lianne J. Woodward, Caron A. C. Clark, Samudragupta Bora, Terrie E. Inder Background Cerebral white matter abnormalities on term MRI are a strong predictor of motor disability in children born very preterm. However, their contribution to cognitive impairment is less certain. Objective Examine relationships between the presence and severity of cerebral white matter abnormalities on neonatal MRI and a range of neurocognitive outcomes assessed at ages 4 and 6 years. Design/Methods The study sample consisted of a regionally representative cohort of 104 very preterm (≤32 weeks gestation) infants born from 1998–2000 and a comparison group of 107 full-term infants. At term equivalent, all preterm infants underwent a structural MRI scan that was analyzed qualitatively for the presence and severity of cerebral white matter abnormalities, including cysts, signal abnormalities, loss of white matter volume, ventriculomegaly, and corpus callosal thinning/myelination. At corrected ages 4 and 6 years, all children underwent a comprehensive neurodevelopmental assessment that included measures of general intellectual ability, language development, and executive functioning. Results At 4 and 6 years, very preterm children without cerebral white matter abnormalities showed no apparent neurocognitive impairments relative to their full-term peers on any of the domain specific measures of intelligence, language, and executive functioning. In contrast, children born very preterm with mild and moderate-to-severe white matter abnormalities were characterized by performance impairments across all measures and time points, with more severe cerebral abnormalities being associated with increased risks of cognitive impairment. These associations persisted after adjustment for gender, neonatal medical risk factors, and family social risk. Conclusions Findings highlight the importance of cerebral white matter connectivity for later intact cognitive functioning amongst children born very preterm. Preterm born children without cerebral white matter abnormalities on their term MRI appear to be spared many of the cognitive impairments commonly associated with preterm birth. Further follow-up will be important to assess whether this finding persists into the school years.
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  • 56
    Publication Date: 2012-12-18
    Description: by Lynnae M. Smith, Mya C. Schiess, Mary P. Coffey, Andrea C. Klaver, David A. Loeffler α-synuclein is thought to play a key role in Parkinson’s disease (PD) because it is the major protein in Lewy bodies, and because its gene mutations, duplication, and triplication are associated with early-onset PD. There are conflicting reports as to whether serum and plasma concentrations of α-synuclein and anti-α-synuclein antibodies differ between PD and control subjects. The objectives of this study were to compare the levels of α-synuclein and its antibodies between individuals with typical PD (n = 14), atypical Parkinson syndromes (n = 11), idiopathic rapid eye movement sleep behavior disorder (n = 10), and healthy controls (n = 9), to assess the strength of association between these serum proteins, and to determine group sizes needed for a high probability (80% power) of detecting statistical significance for 25% or 50% differences between typical PD and control subjects for these measurements. Analysis of log-transformed data found no statistically significant differences between groups for either α-synuclein or its antibodies. The concentrations of these proteins were weakly correlated (Spearman rho = 0.16). In subjects with typical PD and atypical Parkinson syndromes, anti-α-synuclein antibody levels above 1.5 µg/ml were detected only in subjects with no more than four years of clinical disease. Power analysis indicated that 236 and 73 samples per group would be required for an 80% probability that 25% and 50% differences, respectively, in mean α-synuclein levels between typical PD and control subjects would be statistically significant; for anti-α-synuclein antibodies, 283 and 87 samples per group would be required. Our findings are consistent with those previous studies which suggested that serum concentrations of α-synuclein and its antibodies are not significantly altered in PD.
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  • 57
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    Public Library of Science (PLoS)
    In: PLoS ONE
    Publication Date: 2012-12-18
    Description: by Jan Churan, Daniel Guitton, Christopher C. Pack Visual neurons have spatial receptive fields that encode the positions of objects relative to the fovea. Because foveate animals execute frequent saccadic eye movements, this position information is constantly changing, even though the visual world is generally stationary. Interestingly, visual receptive fields in many brain regions have been found to exhibit changes in strength, size, or position around the time of each saccade, and these changes have often been suggested to be involved in the maintenance of perceptual stability. Crucial to the circuitry underlying perisaccadic changes in visual receptive fields is the superior colliculus (SC), a brainstem structure responsible for integrating visual and oculomotor signals. In this work we have studied the time-course of receptive field changes in the SC. We find that the distribution of the latencies of SC responses to stimuli placed outside the fixation receptive field is bimodal: The first mode is comprised of early responses that are temporally locked to the onset of the visual probe stimulus and stronger for probes placed closer to the classical receptive field. We suggest that such responses are therefore consistent with a perisaccadic rescaling, or enhancement, of weak visual responses within a fixed spatial receptive field. The second mode is more similar to the remapping that has been reported in the cortex, as responses are time-locked to saccade onset and stronger for stimuli placed in the postsaccadic receptive field location. We suggest that these two temporal phases of spatial updating may represent different sources of input to the SC.
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  • 58
    Publication Date: 2012-12-18
    Description: by Chengchao Zhou, Jie Chu, Jinan Liu, Ruoyan Gai Tobe, Hong Gen, Xingzhou Wang, Wengui Zheng, Lingzhong Xu Adherence to TB treatment is the most important requirement for efficient TB control. Migrant TB patients’ “migratory” nature affects the adherence negatively, which presents an important barrier for National TB Control Program in China. Therefore, TB control among migrants is of high importance.The aim of this study is to describe adherence to TB treatment among migrant TB patients and to identify factors associated with adherence. A total of 12 counties/districts of Shandong Province, China were selected as study sites. 314 confirmed smear positive TB patients were enrolled between August 2 nd 2008 and October 17 th 2008, 16% of whom were non-adherent to TB therapy. Risk factors for non-adherence were: the divorced or bereft of spouse, patients not receiving TB-related health education before chemotherapy, weak incentives for treatment adherence, and self supervision on treatment. Based on the risk factors identified, measures are recommended such as implementing health education for all migrant patients before chemotherapy and encouraging primary care workers to supervise patients.
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  • 59
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    Public Library of Science (PLoS)
    In: PLoS ONE
    Publication Date: 2012-12-18
    Description: by Hong-Lim Kim, Ji Hyun Jeon, Tae-Hyung Koo, U-Young Lee, Eojin Jeong, Myung-Hoon Chun, Jung-Il Moon, Stephen C. Massey, In-Beom Kim In the mammalian retina, bipolar cells and ganglion cells which stratify in sublamina a of the inner plexiform layer (IPL) show OFF responses to light stimuli while those that stratify in sublamina b show ON responses. This functional relationship between anatomy and physiology is a key principle of retinal organization. However, there are at least three types of retinal neurons, including intrinsically photosensitive retinal ganglion cells (ipRGCs) and dopaminergic amacrine cells, which violate this principle. These cell types have light-driven ON responses, but their dendrites mainly stratify in sublamina a of the IPL, the OFF sublayer. Recent anatomical studies suggested that certain ON cone bipolar cells make axonal or ectopic synapses as they descend through sublamina a , thus providing ON input to cells which stratify in the OFF sublayer. Using immunoelectron microscopy with 3-dimensional reconstruction, we have identified axonal synapses of ON cone bipolar cells in the rabbit retina. Ten calbindin ON cone bipolar axons made en passant ribbon synapses onto amacrine or ganglion dendrites in sublamina a of the IPL. Compared to the ribbon synapses made by bipolar terminals, these axonal ribbon synapses were characterized by a broad postsynaptic element that appeared as a monad and by the presence of multiple short synaptic ribbons. These findings confirm that certain ON cone bipolar cells can provide ON input to amacrine and ganglion cells whose dendrites stratify in the OFF sublayer via axonal synapses. The monadic synapse with multiple ribbons may be a diagnostic feature of the ON cone bipolar axonal synapse in sublamina a . The presence of multiple ribbons and a broad postsynaptic density suggest these structures may be very efficient synapses. We also identified axonal inputs to ipRGCs with the architecture described above.
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  • 60
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    Oxford University Press
    Publication Date: 2012-12-20
    Print ISSN: 0964-6906
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  • 61
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    Oxford University Press
    Publication Date: 2012-12-20
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  • 62
    Publication Date: 2012-12-20
    Description: Frontonasal dysplasia (FND) refers to a class of midline facial malformations caused by abnormal development of the facial primordia. The term encompasses a spectrum of severities but characteristic features include combinations of ocular hypertelorism, malformations of the nose and forehead and clefting of the facial midline. Several recent studies have drawn attention to the importance of Alx homeobox transcription factors during craniofacial development. Most notably, loss of Alx1 has devastating consequences resulting in severe orofacial clefting and extreme microphthalmia. In contrast, mutations of Alx3 or Alx4 cause milder forms of FND. Whilst Alx1 , Alx3 and Alx4 are all known to be expressed in the facial mesenchyme of vertebrate embryos, little is known about the function of these proteins during development. Here, we report the establishment of a zebrafish model of Alx -related FND. Morpholino knock-down of zebrafish alx1 expression causes a profound craniofacial phenotype including loss of the facial cartilages and defective ocular development. We demonstrate for the first time that Alx1 plays a crucial role in regulating the migration of cranial neural crest (CNC) cells into the frontonasal primordia. Abnormal neural crest migration is coincident with aberrant expression of foxd3 and sox10 , two genes previously suggested to play key roles during neural crest development, including migration, differentiation and the maintenance of progenitor cells. This novel function is specific to Alx1, and likely explains the marked clinical severity of Alx1 mutation within the spectrum of Alx -related FND.
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  • 63
    Publication Date: 2012-12-20
    Description: Activating somatic and germline mutations of closely related RAS genes (H, K, N) have been found in various types of cancer and in patients with developmental disorders, respectively. The involvement of the RAS signalling pathways in developmental disorders has recently emerged as one of the most important drivers in RAS research. In the present study, we investigated the biochemical and cell biological properties of two novel missense KRAS mutations (Y71H and K147E). Both mutations affect residues that are highly conserved within the RAS family. KRAS Y71H showed no clear differences to KRAS wt , except for an increased binding affinity for its major effector, the RAF1 kinase. Consistent with this finding, even though we detected similar levels of active KRAS Y71H when compared with wild-type protein, we observed an increased activation of MEK1/2, irrespective of the stimulation conditions. In contrast, KRAS K147E exhibited a tremendous increase in nucleotide dissociation generating a self-activating RAS protein that can act independently of upstream signals. As a consequence, levels of active KRAS K147E were strongly increased regardless of serum stimulation and similar to the oncogenic KRAS G12V . In spite of this, KRAS K147E downstream signalling did not reach the level triggered by oncogenic KRAS G12V , especially because KRAS K147E was downregulated by RASGAP and moreover exhibited a 2-fold lower affinity for RAF kinase. Here, our findings clearly emphasize that individual RAS mutations, despite being associated with comparable phenotypes of developmental disorders in patients, can cause remarkably diverse biochemical effects with a common outcome, namely a rather moderate gain-of-function.
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  • 64
    Publication Date: 2012-12-20
    Description: Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominantly inherited disorder, which is caused by a pathological expansion of a polyglutamine (polyQ) tract in the coding region of the ATXN2 gene. Like other ataxias, SCA2 most overtly affects Purkinje cells (PCs) in the cerebellum. Using a transgenic mouse model expressing a full-length ATXN2 Q127 -complementary DNA under control of the Pcp2 promoter (a PC-specific promoter), we examined the time course of behavioral, morphologic, biochemical and physiological changes with particular attention to PC firing in the cerebellar slice. Although motor performance began to deteriorate at 8 weeks of age, reductions in PC number were not seen until after 12 weeks. Decreases in the PC firing frequency first showed at 6 weeks and paralleled deterioration of motor performance with progression of disease. Transcription changes in several PC-specific genes such as Calb1 and Pcp2 mirrored the time course of changes in PC physiology with calbindin-28 K changes showing the first small, but significant decreases at 4 weeks. These results emphasize that in this model of SCA2, physiological and behavioral phenotypes precede morphological changes by several weeks and provide a rationale for future studies examining the effects of restoration of firing frequency on motor function and prevention of future loss of PCs.
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  • 65
    Publication Date: 2012-12-20
    Description: Balancing selection has maintained human leukocyte antigen (HLA) allele diversity, but it is unclear whether this selection is symmetric (all heterozygotes are comparable and all homozygotes are comparable in terms of fitness) or asymmetric (distinct heterozygote genotypes display greater fitness than others). We tested the hypothesis that HLA is under asymmetric balancing selection in populations by estimating allelic branch lengths from genetic sequence data encoding peptide-binding domains. Significant deviations indicated changes in the ratio of terminal to internal branch lengths. Such deviations could arise even if no individual alleles present a strikingly altered branch length (e.g. if there is an overall distortion, with all or many terminal branches being longer than expected). DQ and DP loci were also analyzed as haplotypes. Using allele frequencies for 419 distinct populations in 10 geographical regions, we examined population differentiation in alleles within and between regions, and the relationship between allelic branch length and frequency. The strongest evidence for asymmetrical balancing selection was observed for HLA-DRB1 , HLA-B and HLA-DPA1 , with significant deviation ( P ≤ 1.1 x 10 –4 ) in about half of the populations. There were significant results at all loci except HLA-DQB1 / DQA1 . We observed moderate genetic variation within and between geographic regions, similar to the rest of the genome. Branch length was not correlated with allele frequency. In conclusion, sequence data suggest that balancing selection in HLA is asymmetric (some heterozygotes enjoy greater fitness than others). Because HLA polymorphism is crucial for pathogen resistance, this may manifest as a frequency-dependent selection with fluctuation in the fitness of specific heterozygotes over time.
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  • 66
    Publication Date: 2012-12-20
    Description: Birt–Hogg–Dubé syndrome (BHD) is a human cancer disorder caused by mutations in the tumor suppressor gene Folliculin ( FLCN ) with unknown biological functions. Here, we show that the Drosophila homolog of FLCN, dFLCN (a.k.a. dBHD ) localizes to the nucleolus and physically interacts with the 19S proteasomal ATPase, Rpt4, a nucleolar resident and known regulator of rRNA transcription. Downregulation of dFLCN resulted in an increase in nucleolar volume and upregulation of rRNA synthesis, whereas dFLCN overexpression reduced rRNA transcription and counteracted the effects of Rpt4 on rRNA production by preventing the association of Rpt4 with the rDNA locus. We further show that human FLCN exhibited evolutionarily conserved function and that Rpt4 knockdown inhibits the growth of FLCN-deficient human renal cancer cells in mouse xenografts. Our study suggests that FLCN functions as a tumor suppressor by negatively regulating rRNA synthesis.
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  • 67
    Publication Date: 2012-12-20
    Description: KitL, via its receptor cKit, supports primordial germ cell (PGC) growth, survival, migration and reprogramming to pluripotent embryonic germ cells (EGCs). However, the signaling downstream of KitL and its regulation in PGCs remain unclear. A constitutively activating mutation, cKit V558 , causes gain-of-function phenotypes in mast cells and intestines, and gastrointestinal stromal tumors (GISTs) when heterozygous. Unexpectedly, we find that PGC growth is not significantly affected in cKit V558 heterozygotes, whereas in homozygotes, increased apoptosis and inefficient migration lead to the depletion of PGCs. Through genetic studies, we reveal that this oncogenic cKit allele exhibits loss-of-function behavior in PGCs distinct from that in GIST development. Examination of downstream signaling in GISTs from cKit V558/+ mice confirmed hyperphosphorylation of AKT and ERK, but both remain unperturbed in cKit V558/+ PGCs and EGCs. In contrast, we find reduced activation of ERK1/2 and JNK1 in cKit V558 homozygous PGCs and EGCs. Inhibiting JNK, though not ERK1/2, increased apoptosis of wild-type PGCs, but did not further affect the already elevated apoptosis of cKit V558 / V558 PGCs. These results demonstrate a cell-context-dependent response to the cKit V558 mutation. We propose that AKT overload protection and JNK-mediated survival comprise PGC-specific mechanisms for regulating cKit signaling.
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  • 68
    Publication Date: 2012-12-20
    Description: TDP-43 is an evolutionarily conserved RNA-binding protein currently under intense investigation for its involvement in the molecular pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). TDP-43 is normally localized in the nucleus, but translocated to the cytoplasm in diseased neurons. The endogenous functions of TDP-43 in the nervous system remain poorly understood. Here, we show that the loss of Drosophila TDP-43 (dTDP-43) results in an increased production of sensory bristles and sensory organ precursor (SOP) cells on the notum of some but not all flies. The location of ectopic SOPs varies among mutant flies. The penetrance of this novel phenotype is dependent on the gender and sensitive to environmental influences. A similar SOP phenotype was also observed on the wing and in the embryos. Overexpression of dTDP-43 causes both loss and ectopic production of SOPs. Ectopic expression of ALS-associated mutant human TDP-43 (hTDP-43 M337V and hTDP-43 Q331K ) produces a less severe SOP phenotype than hTDP-43 WT , indicating a partial loss of function of mutant hTDP-43. In dTDP-43 mutants, miR-9a expression is significantly reduced. Genetic interaction studies further support the notion that dTDP-43 acts through miR-9a to control the precision of SOP specification. These findings reveal a novel role for endogenous TDP-43 in neuronal specification and suggest that the FTD/ALS-associated RNA-binding protein TDP-43 functions to ensure the robustness of genetic control programs.
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  • 69
    Publication Date: 2012-12-20
    Description: Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most frequent known cause of late-onset Parkinson's disease (PD). To explore the therapeutic potential of small molecules targeting the LRRK2 kinase domain, we characterized two LRRK2 kinase inhibitors, TTT-3002 and LRRK2-IN1, for their effects against LRRK2 activity in vitro and in Caenorhabditis elegans models of LRRK2-linked neurodegeneration. TTT-3002 and LRRK2-IN1 potently inhibited in vitro kinase activity of LRRK2 wild-type and mutant proteins, attenuated phosphorylation of cellular LRRK2 and rescued neurotoxicity of mutant LRRK2 in transfected cells. To establish whether LRRK2 kinase inhibitors can mitigate pathogenesis caused by different mutations including G2019S and R1441C located within and outside of the LRRK2 kinase domain, respectively, we evaluated effects of TTT-3002 and LRRK2-IN1 against R1441C- and G2019S-induced neurodegeneration in C. elegans models. TTT-3002 and LRRK2-IN1 rescued the behavioral deficit characteristic of dopaminergic impairment in transgenic C. elegans expressing human R1441C- and G2019S-LRRK2. The inhibitors displayed nanomolar to low micromolar rescue potency when administered either pre-symptomatically or post-symptomatically, indicating both prevention and reversal of the dopaminergic deficit. The same treatments also led to long-lasting prevention and rescue of neurodegeneration. In contrast, TTT-3002 and LRRK2-IN1 were ineffective against the neurodegenerative phenotype in transgenic worms carrying the inhibitor-resistant A2016T mutation of LRRK2, suggesting that they elicit neuroprotective effects in vivo by targeting LRRK2 specifically. Our findings indicate that the LRRK2 kinase activity is critical for neurodegeneration caused by R1441C and G2019S mutations, suggesting that kinase inhibition of LRRK2 may represent a promising therapeutic strategy for PD.
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  • 70
    Publication Date: 2012-12-20
    Description: Mitochondrial DNA (mtDNA) mutations leading to the disruption of respiratory complex I (CI) have been shown to exhibit anti-tumorigenic effects, at variance with those impairing only the function but not the assembly of the complex, which appear to contribute positively to cancer development. Owing to the challenges in the analysis of the multi-copy mitochondrial genome, it is yet to be determined whether tumour-associated mtDNA lesions occur as somatic modifying factors or as germ-line predisposing elements. Here we investigated the whole mitochondrial genome sequence of 20 pituitary adenomas with oncocytic phenotype and identified pathogenic and/or novel mtDNA mutations in 60% of the cases. Using highly sensitive techniques, namely fluorescent PCR and allele-specific locked nucleic acid quantitative PCR, we identified the most likely somatic nature of these mutations in our sample set, since none of the mutations was detected in the corresponding blood tissue of the patients analysed. Furthermore, we have subjected a series of 48 pituitary adenomas to a high-resolution array comparative genomic hybridization analysis, which revealed that CI disruptive mutations, and the oncocytic phenotype, significantly correlate with low number of chromosomal aberrations in the nuclear genome. We conclude that CI disruptive mutations in pituitary adenomas are somatic modifiers of tumorigenesis most likely contributing not only to the development of oncocytic change, but also to a less aggressive tumour phenotype, as indicated by a stable karyotype.
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  • 71
    Publication Date: 2012-12-20
    Description: Functional loss of SMN1 causes proximal spinal muscular atrophy (SMA), the most common genetic condition accounting for infant lethality. Hence, the hypomorphic copy gene SMN2 is the only resource of functional SMN protein in SMA patients and influences SMA severity in a dose-dependent manner. Consequently, current therapeutic approaches focus on SMN2 . Histone deacetylase inhibitors (HDACi), such as the short chain fatty acid VPA (valproic acid), ameliorate the SMA phenotype by activating the SMN2 expression. By analyzing blood SMN2 expression in 16 VPA-treated SMA patients, about one-third of individuals were identified as positive responders presenting increased SMN2 transcript levels. In 66% of enrolled patients, a concordant response was detected in the respective fibroblasts. Most importantly, by taking the detour of reprograming SMA patients' fibroblasts, we showed that the VPA response was maintained even in GABAergic neurons derived from induced pluripotent stem cells (iPS) cells. Differential expression microarray analysis revealed a complete lack of response to VPA in non-responders, which was associated with an increased expression of the fatty acid translocase CD36. The pivotal role of CD36 as the cause of non-responsiveness was proven in various in vitro approaches. Most importantly, knockdown of CD36 in SMA fibroblasts converted non- into pos-responders. In summary, the concordant response from blood to the central nervous system (CNS) to VPA may allow selection of pos-responders prior to therapy. Increased CD36 expression accounts for VPA non-responsiveness. These findings may be essential not only for SMA but also for other diseases such as epilepsy or migraine frequently treated with VPA.
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  • 72
    Publication Date: 2012-12-20
    Description: Rett syndrome (RTT) is a neurodevelopmental disorder caused primarily by mutations of the X-linked MECP2 gene. Although the loss of MeCP2 function affects many neural systems, impairments of catecholaminergic function have been hypothesized to underlie several of the cardinal behavioral deficits of RTT patients and Mecp2-deficient mice. Although recent Mecp2 reactivation studies indicate that RTT may be a reversible condition, it remains unclear whether specifically preserving Mecp2 function within a specific system will be sufficient to convey beneficial effects. Here, we test whether the selective preservation of Mecp2 within catecholaminergic cells will improve the phenotype of Mecp2-deficient mice. Our results show that this targeted preservation of Mecp2 significantly improves the lifespan, phenotypic severity and cortical epileptiform discharge activity of both male and female Mecp2-deficient mice. Further, we found that the catecholaminergic preservation of Mecp2 also improves the ambulatory rate, rearing activity, motor coordination, anxiety and nest-building performances of Mecp2-deficient mice of each gender. Interestingly, our results also revealed a gender-specific improvement, as specific cortical and hippocampal electroencephalographic abnormalities were significantly improved in male, but not female, rescue mice. Collectively, these results support the role of the catecholaminergic system in the pathogenesis of RTT and provide proof-of-principle that restoring MeCP2 function within this specific system could represent a treatment strategy for RTT.
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  • 73
    Publication Date: 2012-12-20
    Description: Mutations in COL4A1 have been identified in families with hereditary small vessel disease of the brain presumably due to a dominant-negative mechanism. Here, we report on two novel mutations in COL4A1 in two families with porencephaly, intracerebral hemorrhage and severe white matter disease caused by haploinsufficiency. Two families with various clinical presentations of cerebral microangiopathy and autosomal dominant inheritance were examined. Clinical, neuroradiological and genetic investigations were performed. Electron microscopy of the skin was also performed. In one of the families, sequence analysis revealed a one base deletion, c.2085del, leading to a frameshift and a premature stopcodon, p.(Gly696fs). In the other family, a splice site mutation was identified, c.2194-1G〉A, which most likely leads to skipping of an exon with a frameshift and premature termination as a result. In fibroblasts of affected individuals from both the families, nonsense-mediated decay (NMD) of the mutant COL4A1 messenger RNAs (mRNAs) and a clear reduction of COL4A1 protein expression were demonstrated, indicating haploinsufficiency of COL4A1. Moreover, thickening of the capillary basement membrane in the skin was documented, similar to reports in patients with COL4A1 missense mutations. These findings suggest haploinsufficiency, a different mechanism from the commonly assumed dominant-negative effect, for COL4A1 mutations as a cause of (antenatal) intracerebral hemorrhage and white matter disease.
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  • 74
    Publication Date: 2012-12-20
    Description: by Bryan Bedrosian, Derek Craighead, Ross Crandall Studies suggest hunter discarded viscera of big game animals (i.e., offal) is a source of lead available to scavengers. We investigated the incidence of lead exposure in bald eagles in Wyoming during the big game hunting season, the influx of eagles into our study area during the hunt, the geographic origins of eagles exposed to lead, and the efficacy of using non-lead rifle ammunition to reduce lead in eagles. We tested 81 blood samples from bald eagles before, during and after the big game hunting seasons in 2005–2010, excluding 2008, and found eagles had significantly higher lead levels during the hunt. We found 24% of eagles tested had levels indicating at least clinical exposure (〉60 ug/dL) during the hunt while no birds did during the non-hunting seasons. We performed driving surveys from 2009–2010 to measure eagle abundance and found evidence to suggest that eagles are attracted to the study area during the hunt. We fitted 10 eagles with satellite transmitters captured during the hunt and all migrated south after the cessation of the hunt. One returned to our study area while the remaining nine traveled north to summer/breed in Canada. The following fall, 80% returned to our study area for the hunting season, indicating that offal provides a seasonal attractant for eagles. We fitted three local breeding eagles with satellite transmitters and none left their breeding territories to feed on offal during the hunt, indicating that lead ingestion may be affecting migrants to a greater degree. During the 2009 and 2010 hunting seasons we provided non-lead rifle ammunition to local hunters and recorded that 24% and 31% of successful hunters used non-lead ammunition, respectively. We found the use of non-lead ammunition significantly reduced lead exposure in eagles, suggesting this is a viable solution to reduce lead exposure in eagles.
    Electronic ISSN: 1932-6203
    Topics: Medicine , Natural Sciences in General
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  • 75
    Publication Date: 2012-12-20
    Description: by Chandrashekhar T. Sreeramareddy, T. N. Sathyanarayana, H. N. Harsha Kumar Background Information about utilization of health services and associated factors are useful for improving service delivery to achieve universal health coverage. Methods Data on a sample of ever-married women from India Demographic and Health survey 2005–06 was used. Mothers of children aged 0–59 months were asked about child’s illnesses and type of health facilities where treatment was given during 15 days prior to the survey date. Type of health facilities were grouped as informal provider, public provider and private provider. Factors associated with utilization of health services for diarrhea and fever/cough was assessed according to Andersen’s health behavior model. Multinomial logistic regression analyses were done considering sampling weights for complex sampling design. Results A total of 48,679 of ever-married women reported that 9.1% 14.8% and 17.67% of their children had diarrhea, fever and cough respectively. Nearly one-third of the children with diarrhea and fever/cough did not receive any treatment. Two-thirds of children who received treatment were from private health care providers (HCPs). Among predisposing factors, children aged 1–2 years and those born at health facility (public/private) were more likely to be taken to any type of HCP during illness. Among enabling factors, as compared to poorer household, wealthier households were 2.5 times more likely to choose private HCPs for any illness. Children in rural areas were likely to be taken to any type of HCP for diarrhea but rural children were less likely to utilize private HCP for fever/cough. ‘Need’ factors i.e. children having severe symptoms were 2–3 times more likely to be taken to any type of HCP. Conclusion Private HCPs were preferred for treatment of childhood illnesses. Involvement of private HCPs may be considered while planning child health programs. Health insurance scheme for childhood illnesses may to protect economically weaker sections from out-of-pocket health expenditure during child illness.
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  • 76
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    In: PLoS ONE
    Publication Date: 2012-12-20
    Description: by Michael T. Cheeseman, Kate Vowell, Tertius A. Hough, Lynn Jones, Paras Pathak, Hayley E. Tyrer, Michelle Kelly, Roger Cox, Madhuri V. Warren, Jo Peters GNAS/Gnas encodes G s α that is mainly biallelically expressed but shows imprinted expression in some tissues. In Albright Hereditary Osteodystrophy (AHO) heterozygous loss of function mutations of GNAS can result in ectopic ossification that tends to be superficial and attributable to haploinsufficiency of biallelically expressed G s α. Oed-Sml is a point missense mutation in exon 6 of the orthologous mouse locus Gnas . We report here both the late onset ossification and occurrence of benign cutaneous fibroepithelial polyps in Oed-Sml . These phenotypes are seen on both maternal and paternal inheritance of the mutant allele and are therefore due to an effect on biallelically expressed G s α. The ossification is confined to subcutaneous tissues and so resembles the ossification observed with AHO. Our mouse model is the first with both subcutaneous ossification and fibroepithelial polyps related to G s α deficiency. It is also the first mouse model described with a clinically relevant phenotype associated with a point mutation in G s α and may be useful in investigations of the mechanisms of heterotopic bone formation. Together with earlier results, our findings indicate that G s α signalling pathways play a vital role in repressing ectopic bone formation.
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  • 77
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    Public Library of Science (PLoS)
    In: PLoS ONE
    Publication Date: 2012-12-20
    Description: by Xavier Bosch, Cristina Hernández, Juan M. Pericas, Pamela Doti, Ana Marušić Background It is not clear which research misconduct policies are adopted by biomedical journals. This study assessed the prevalence and content policies of the most influential biomedical journals on misconduct and procedures for handling and responding to allegations of misconduct. Methods We conducted a cross-sectional study of misconduct policies of 399 high-impact biomedical journals in 27 biomedical categories of the Journal Citation Reports in December 2011. Journal websites were reviewed for information relevant to misconduct policies. Results Of 399 journals, 140 (35.1%) provided explicit definitions of misconduct. Falsification was explicitly mentioned by 113 (28.3%) journals, fabrication by 104 (26.1%), plagiarism by 224 (56.1%), duplication by 242 (60.7%) and image manipulation by 154 (38.6%). Procedures for responding to misconduct were described in 179 (44.9%) websites, including retraction, (30.8%) and expression of concern (16.3%). Plagiarism-checking services were used by 112 (28.1%) journals. The prevalences of all types of misconduct policies were higher in journals that endorsed any policy from editors’ associations, Office of Research Integrity or professional societies compared to those that did not state adherence to these policy-producing bodies. Elsevier and Wiley-Blackwell had the most journals included (22.6% and 14.8%, respectively), with Wiley journals having greater a prevalence of misconduct definition and policies on falsification, fabrication and expression of concern and Elsevier of plagiarism-checking services. Conclusions Only a third of top-ranking peer-reviewed journals had publicly-available definitions of misconduct and less than a half described procedures for handling allegations of misconduct. As endorsement of international policies from policy-producing bodies was positively associated with implementation of policies and procedures, journals and their publishers should standardize their policies globally in order to increase public trust in the integrity of the published record in biomedicine.
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  • 78
    Publication Date: 2012-12-20
    Description: by Ru Li, Ehsan Khafipour, Denis O. Krause, Martin H. Entz, Teresa R. de Kievit, W. G. Dilantha Fernando It has been debated how different farming systems influence the composition of soil bacterial communities, which are crucial for maintaining soil health. In this research, we applied high-throughput pyrosequencing of V1 to V3 regions of bacterial 16S rRNA genes to gain further insight into how organic and conventional farming systems and crop rotation influence bulk soil bacterial communities. A 2×2 factorial experiment consisted of two agriculture management systems (organic versus conventional) and two crop rotations (flax-oat-fababean-wheat versus flax-alfalfa-alfalfa-wheat) was conducted at the Glenlea Long-Term Crop Rotation and Management Station, which is Canada’s oldest organic-conventional management study field. Results revealed that there is a significant difference in the composition of bacterial genera between organic and conventional management systems but crop rotation was not a discriminator factor. Organic farming was associated with higher relative abundance of Proteobacteria , while Actinobacteria and Chloroflexi were more abundant in conventional farming. The dominant genera including Blastococcus, Microlunatus, Pseudonocardia, Solirubrobacter, Brevundimonas, Pseudomonas , and Stenotrophomonas exhibited significant variation between the organic and conventional farming systems. The relative abundance of bacterial communities at the phylum and class level was correlated to soil pH rather than other edaphic properties. In addition, it was found that Proteobacteria and Actinobacteria were more sensitive to pH variation.
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  • 79
    Publication Date: 2012-12-20
    Description: by Rohan Steel, Ryan S. Cross, Sarah L. Ellis, Robin L. Anderson Heat induces Hsp70.1 (HSPA1) and Hsc70 (HSPA8) to form complex detergent insoluble cytoplasmic and nuclear structures that are distinct from the cytoskeleton and internal cell membranes. These novel structures have not been observed by earlier immunofluorescence studies as they are obscured by the abundance of soluble Hsp70.1/Hsc70 present in cells. While resistant to detergents, these Hsp70 structures display complex intracellular dynamics and are efficiently disaggregated by ATP, indicating that this pool of Hsp70.1/Hsc70 retains native function and regulation. Hsp70.1 promotes the repair of proteotoxic damage and cell survival after stress. In heated fibroblasts expressing Hsp70.1, Hsp70.1 and Hsc70 complexes are efficiently disaggregated before the cells undergo-heat induced apoptosis. In the absence of Hsp70.1, fibroblasts have increased rates of heat-induced apoptosis and maintain stable insoluble Hsc70 structures. The differences in the intracellular distribution of Hsp70.1 and Hsc70, combined with the ability of Hsp70.1, but not Hsc70, to promote the disaggregation of insoluble Hsp70.1/Hsc70 complexes, indicate that these two closely related proteins perform distinctly different cellular functions in heated cells.
    Electronic ISSN: 1932-6203
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  • 80
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    In: PLoS ONE
    Publication Date: 2012-12-20
    Description: by Jens Mani, Jasmina Makarević, Eva Juengel, Hanns Ackermann, Karen Nelson, Axel Haferkamp, Roman A. Blaheta The pathophysiologic mechanisms behind urologic disease are increasingly being elucidated. The object of this investigation was to evaluate the publication policies of urologic journals during a period of progressively better understanding and management of urologic disease. Based on the ISI Web of Knowledge Journal Citation Reports and the PubMed database, the number and percentage of original experimental, original clinical, review or commentarial articles published between 2002–2010 in six leading urologic journals were analyzed. “British Journal of Urology International”, “European Urology”, “Urologic Oncology-Seminars and Original Investigations” (“Urologic Oncology”), “Urology”, “The Journal of Urology”, and “World Journal of Urology” were chosen, because these journals publish articles in all four categories. The publication policies of the six journals were very heterogeneous during the time period from 2002 to 2010. The percentage of original experimental and original clinical articles, related to all categories, remained the same in “British Journal of Urology International”, “Urologic Oncology”, “Urology” and “The Journal of Urology”. The percentage of experimental reports in “World Journal of Urology” between 2002–2010 significantly increased from 10 to 20%. A distinct elevation in the percentage of commentarial articles accompanied by a reduction of clinical articles became evident in “European Urology” which significantly correlated with a large increase in the journal’s impact factor. No clearly superior policy could be identified with regard to a general increase in the impact factors from all the journals. The publication policy of urologic journals does not expressly reflect the increase in scientific knowledge, which has occurred over the period 2002–2010. One way of increasing the exposure of urologists to research and expand the interface between experimental and clinical research, would be to enlarge the percentage of experimental articles published. There is no indication that such policy would be detrimental to a journal’s impact factor.
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  • 81
    Publication Date: 2012-12-21
    Description: Motivation: Given the current costs of next-generation sequencing, large studies carry out low-coverage sequencing followed by application of methods that leverage linkage disequilibrium to infer genotypes. We propose a novel method that assumes study samples are sequenced at low coverage and genotyped on a genome-wide microarray, as in the 1000 Genomes Project (1KGP). We assume polymorphic sites have been detected from the sequencing data and that genotype likelihoods are available at these sites. We also assume that the microarray genotypes have been phased to construct a haplotype scaffold. We then phase each polymorphic site using an MCMC algorithm that iteratively updates the unobserved alleles based on the genotype likelihoods at that site and local haplotype information. We use a multivariate normal model to capture both allele frequency and linkage disequilibrium information around each site. When sequencing data are available from trios, Mendelian transmission constraints are easily accommodated into the updates. The method is highly parallelizable, as it analyses one position at a time. Results: We illustrate the performance of the method compared with other methods using data from Phase 1 of the 1KGP in terms of genotype accuracy, phasing accuracy and downstream imputation performance. We show that the haplotype panel we infer in African samples, which was based on a trio-phased scaffold, increases downstream imputation accuracy for rare variants (R2 increases by 〉0.05 for minor allele frequency 〈1%), and this will translate into a boost in power to detect associations. These results highlight the value of incorporating microarray genotypes when calling variants from next-generation sequence data. Availability: The method (called MVNcall) is implemented in a C++ program and is available from http://www.stats.ox.ac.uk/~marchini/#software . Contact: marchini@stats.ox.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online.
    Print ISSN: 1367-4803
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  • 82
    Publication Date: 2012-12-21
    Description: Motivation: Accurate alignment of high-throughput RNA-seq data is a challenging and yet unsolved problem because of the non-contiguous transcript structure, relatively short read lengths and constantly increasing throughput of the sequencing technologies. Currently available RNA-seq aligners suffer from high mapping error rates, low mapping speed, read length limitation and mapping biases. Results: To align our large (〉80 billon reads) ENCODE Transcriptome RNA-seq dataset, we developed the Spliced Transcripts Alignment to a Reference (STAR) software based on a previously undescribed RNA-seq alignment algorithm that uses sequential maximum mappable seed search in uncompressed suffix arrays followed by seed clustering and stitching procedure. STAR outperforms other aligners by a factor of 〉50 in mapping speed, aligning to the human genome 550 million 2 x 76 bp paired-end reads per hour on a modest 12-core server, while at the same time improving alignment sensitivity and precision. In addition to unbiased de novo detection of canonical junctions, STAR can discover non-canonical splices and chimeric (fusion) transcripts, and is also capable of mapping full-length RNA sequences. Using Roche 454 sequencing of reverse transcription polymerase chain reaction amplicons, we experimentally validated 1960 novel intergenic splice junctions with an 80–90% success rate, corroborating the high precision of the STAR mapping strategy. Availability and implementation: STAR is implemented as a standalone C++ code. STAR is free open source software distributed under GPLv3 license and can be downloaded from http://code.google.com/p/rna-star/ . Contact: dobin@cshl.edu .
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  • 83
    Publication Date: 2012-12-21
    Description: Motivation: Local motifs are patterns of DNA or protein sequences that occur within a sequence interval relative to a biologically defined anchor or landmark. Current protein motif discovery methods do not adequately consider such constraints to identify biologically significant motifs that are only weakly over-represented but spatially confined. Using negatives, i.e. sequences known to not contain a local motif, can further increase the specificity of their discovery. Results: This article introduces the method DLocalMotif that makes use of positional information and negative data for local motif discovery in protein sequences. DLocalMotif combines three scoring functions, measuring degrees of motif over-representation, entropy and spatial confinement, specifically designed to discriminatively exploit the availability of negative data. The method is shown to outperform current methods that use only a subset of these motif characteristics. We apply the method to several biological datasets. The analysis of peroxisomal targeting signals uncovers several novel motifs that occur immediately upstream of the dominant peroxisomal targeting signal-1 signal. The analysis of proline-tyrosine nuclear localization signals uncovers multiple novel motifs that overlap with C2H2 zinc finger domains. We also evaluate the method on classical nuclear localization signals and endoplasmic reticulum retention signals and find that DLocalMotif successfully recovers biologically relevant sequence properties. Availability: http://bioinf.scmb.uq.edu.au/dlocalmotif/ Contact: m.boden@uq.edu.au Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 84
    Publication Date: 2012-12-20
    Description: Much evidence show that over-expression of epidermal growth factor receptor (EGFR) plays an important role in regulating carcinogenesis. Genetic variations in 3' untranslated region (3'UTR) of gene have been reported to affect gene expression by interfering with microRNAs (miRNAs), which are thought to function as either tumour suppressors or oncogenes by binding to their target mRNA. In this study, we investigated the association between the EGFR 3'UTR 774T〉C polymorphism and bladder cancer risk. We used the TaqMan technology to genotype this genetic variant in a hospital-based case–control study of 908 bladder cancer patients and 1239 controls in a Chinese population. We found that the 774CC genotype was associated with a statistically significantly increased risk of bladder cancer [adjusted odds ratio = 1.29, 95% confidence interval = 1.05–1.58], compared with the 774TT/TC genotype, and this increased risk was more pronounced among subgroups of age 〉 65 years, non-smokers and patients’ tumour invasive stage. Furthermore, luciferase assays in T24 cell showed that EGFR 3'UTR 774 T to C substitution could increase the expression of EGFR, which was consistent with the association study finding. Additionally, we also provide evidence that 774T〉C polymorphism increasing EGFR expression was not regulated by hsa-miR-214 binding. These findings suggested that EGFR 3'UTR 774T〉C polymorphism may contribute to susceptibility to bladder cancer.
    Print ISSN: 0267-8357
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  • 85
    Publication Date: 2012-12-21
    Description: Motivation: Protein–protein interaction (PPI) plays an important role in understanding gene functions, and many computational PPI prediction methods have been proposed in recent years. Despite the extensive efforts, PPI prediction still has much room to improve. Sequence-based co-evolution methods include the substitution rate method and the mirror tree method, which compare sequence substitution rates and topological similarity of phylogenetic trees, respectively. Although they have been used to predict PPI in species with small genomes like Escherichia coli , such methods have not been tested in large scale proteome like Homo sapiens . Result: In this study, we propose a novel sequence-based co-evolution method, co-evolutionary divergence (CD), for human PPI prediction. Built on the basic assumption that protein pairs with similar substitution rates are likely to interact with each other, the CD method converts the evolutionary information from 14 species of vertebrates into likelihood ratios and combined them together to infer PPI. We showed that the CD method outperformed the mirror tree method in three independent human PPI datasets by a large margin. With the arrival of more species genome information generated by next generation sequencing, the performance of the CD method can be further improved. Availability: Source code and support are available at http://mib.stat.sinica.edu.tw/LAP/tmp/CD.rar . Contact: syuan@stat.sinica.edu.tw Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 86
    Publication Date: 2012-12-21
    Description: : In higher eukaryotes, the identification of translation initiation sites (TISs) has been focused on finding these signals in cDNA or mRNA sequences. Using Arabidopsis thaliana ( A.t. ) information, we developed a prediction tool for signals within genomic sequences of plants that correspond to TISs. Our tool requires only genome sequence, not expressed sequences. Its sensitivity/specificity is for A.t. (90.75%/92.2%), for Vitis vinifera (66.8%/94.4%) and for Populus trichocarpa (81.6%/94.4%), which suggests that our tool can be used in annotation of different plant genomes. We provide a list of features used in our model. Further study of these features may improve our understanding of mechanisms of the translation initiation. Availability and implementation: Our tool is implemented as an artificial neural network. It is available as a web-based tool and, together with the source code, the list of features, and data used for model development, is accessible at http://cbrc.kaust.edu.sa/dts . Contact: vladimir.bajic@kaust.edu.sa Supplementary information : Supplementary data are available at Bioinformatics online.
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  • 87
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    Unknown
    Oxford University Press
    Publication Date: 2012-12-21
    Description: Motivation: Pathway or gene set analysis has been widely applied to genomic data. Many current pathway testing methods use univariate test statistics calculated from individual genomic markers, which ignores the correlations and interactions between candidate markers. Random forests-based pathway analysis is a promising approach for incorporating complex correlation and interaction patterns, but one limitation of previous approaches is that pathways have been considered separately, thus pathway cross-talk information was not considered. Results: In this article, we develop a new pathway hunting algorithm for survival outcomes using random survival forests, which prioritize important pathways by accounting for gene correlation and genomic interactions. We show that the proposed method performs favourably compared with five popular pathway testing methods using both synthetic and real data. We find that the proposed methodology provides an efficient and powerful pathway modelling framework for high-dimensional genomic data. Availability: The R code for the analysis used in this article is available upon request. Contact: xi.steven.chen@gmail.com Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 88
    Publication Date: 2012-12-21
    Description: Motivation: PacBio sequencers produce two types of characteristic reads (continuous long reads: long and high error rate and circular consensus sequencing: short and low error rate), both of which could be useful for de novo assembly of genomes. Currently, there is no available simulator that targets the specific generation of PacBio libraries. Results: Our analysis of 13 PacBio datasets showed characteristic features of PacBio reads (e.g. the read length of PacBio reads follows a log-normal distribution). We have developed a read simulator, PBSIM, that captures these features using either a model-based or sampling-based method. Using PBSIM, we conducted several hybrid error correction and assembly tests for PacBio reads, suggesting that a continuous long reads coverage depth of at least 15 in combination with a circular consensus sequencing coverage depth of at least 30 achieved extensive assembly results. Availability: PBSIM is freely available from the web under the GNU GPL v2 license ( http://code.google.com/p/pbsim/ ). Contact: mhamada@k.u-tokyo.ac.jp Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 89
    Publication Date: 2012-12-21
    Description: : Drugster is a fully interactive pipeline designed to break the command line barrier and introduce a new user-friendly environment to perform drug design, lead and structure optimization experiments through an efficient combination of the PDB2PQR, Ligbuilder, Gromacs and Dock suites. Our platform features a novel workflow that guides the user through each logical step of the iterative 3D structural optimization setup and drug design process, by providing a seamless interface to all incorporated packages. Availability: Drugster can be freely downloaded via our dedicated server system at http://www.bioacademy.gr/bioinformatics/drugster/ . Contact: dvlachakis@bioacademy.gr .
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  • 90
    Publication Date: 2012-12-21
    Description: XiP (eXtensible integrative Pipeline) is a flexible, editable and modular environment with a user-friendly interface that does not require previous advanced programming skills to run, construct and edit workflows. XiP allows the construction of workflows by linking components written in both R and Java, the analysis of high-throughput data in grid engine systems and also the development of customized pipelines that can be encapsulated in a package and distributed. XiP already comes with several ready-to-use pipeline flows for the most common genomic and transcriptomic analysis and ~300 computational components. Availability: XiP is open source, freely available under the Lesser General Public License (LGPL) and can be downloaded from http://xip.hgc.jp . Contact: nagasaki@megabank.tohoku.ac.jp
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  • 91
    Publication Date: 2012-12-21
    Description: Existing repositories for experimental datasets typically capture snapshots of data acquired using a single experimental technique and often require manual population and continual curation. We present a storage system for heterogeneous research data that performs dynamic automated indexing to provide powerful search, discovery and collaboration features without the restrictions of a structured repository. ADAM is able to index many commonly used file formats generated by laboratory assays and therefore offers specific advantages to the experimental biology community. However, it is not domain specific and can promote sharing and re-use of working data across scientific disciplines. Availability and implementation: ADAM is implemented using Java and supported on Linux. It is open source under the GNU General Public License v3.0. Installation instructions, binary code, a demo system and virtual machine image and are available at http://www.imperial.ac.uk/bioinfsupport/resources/software/adam . Contact: m.woodbridge@imperial.ac.uk
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  • 92
    Publication Date: 2012-12-21
    Description: : Drug versus Disease (DvD) provides a pipeline, available through R or Cytoscape, for the comparison of drug and disease gene expression profiles from public microarray repositories. Negatively correlated profiles can be used to generate hypotheses of drug-repurposing, whereas positively correlated profiles may be used to infer side effects of drugs. DvD allows users to compare drug and disease signatures with dynamic access to databases Array Express, Gene Expression Omnibus and data from the Connectivity Map. Availability and implementation: R package (submitted to Bioconductor) under GPL 3 and Cytoscape plug-in freely available for download at www.ebi.ac.uk/saezrodriguez/DVD/ . Contact: saezrodriguez@ebi.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online.
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  • 93
    Publication Date: 2012-12-21
    Description: by Naresh C. Laddha, Mitesh Dwivedi, Rasheedunnisa Begum Abstract Tumor Necrosis Factor (TNF)-α, is a paracrine inhibitor of melanocytes, which plays a critical role in the pathogenesis of several autoimmune diseases including vitiligo, as abnormal immune responses have frequently been observed in vitiligo patients. Moreover, vitiligo patients show higher lesion levels of TNF-α. Genetic polymorphisms in the promoter region of TNF-α are involved in the regulation of its expression. The present study explores TNF -α promoter polymorphisms and correlates them with TNF-α transcript and protein levels in vitiligo patients and controls of Gujarat along with its effect on disease onset and progression. PCR-RFLP technique was used for genotyping of these polymorphisms in 977 vitiligo patients and 990 controls. TNF-α transcript and protein levels were measured by Real time PCR and ELISA respectively. The genotype and allele frequencies for the investigated polymorphisms were significantly associated with vitiligo patients. The study revealed significant increase in TNF -α transcript and protein levels in vitiligo patients compared to controls. In particular, haplotypes: AATCC, AACCT, AGTCT, GATCT, GATCC and AGCCT were found to increase the TNF-α levels in vitiligo patients. Analysis of TNF-α levels based on the gender and disease progression suggests that female patients and patients with active vitiligo had higher levels of TNF-α. Also, the TNF-α levels were high in patients with generalized vitiligo as compared to localized vitiligo. Age of onset analysis of the disease suggests that the haplotypes: AACAT, AACCT, AATCC and AATCT had a profound effect in the early onset of the disease. Moreover, the analysis suggests that female patients had an early onset of vitiligo. Overall, our results suggest that TNF -α promoter polymorphisms may be genetic risk factors for susceptibility and progression of the disease. The up-regulation of TNF -α transcript and protein levels in individuals with susceptible haplotypes advocates the crucial role of TNF-α in autoimmune pathogenesis of vitiligo.
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  • 94
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    Unknown
    Public Library of Science (PLoS)
    In: PLoS ONE
    Publication Date: 2012-12-21
    Description: by Subhadeep Chakrabarti, Sandra T. Davidge Estrogen, the female sex hormone, is known to exert anti-inflammatory and anti-atherogenic effects. Traditionally, estrogen effects were believed to be largely mediated through the classical estrogen receptors (ERs). However, there is increasing evidence that G-protein coupled receptor 30 (GPR30), a novel estrogen receptor, can mediate many estrogenic effects on the vasculature. Despite this, the localization and functional significance of GPR30 in the human vascular endothelium remains poorly understood. Given this background, we examined the subcellular location and potential anti-inflammatory roles of GPR30 using human umbilical vein endothelial cells as a model system. Inflammatory changes were induced by treatment with tumor necrosis factor (TNF), a pro-inflammatory cytokine involved in atherogenesis and many other inflammatory conditions. We found that GPR30 was located predominantly in the endothelial cell nuclei. Treatment with the selective GPR30 agonist G-1 partially attenuated the TNF induced upregulation of pro-inflammatory proteins such as intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). This effect was completely abolished by the selective GPR30 antagonist G-15, suggesting that it was indeed mediated in a GPR30 dependent manner. Interestingly, estrogen alone had no effects on TNF-treated endothelium. Concomitant activation of the classical ERs blocked the anti-inflammatory effects of G-1, indicating opposing effects of GPR30 and the classical ERs. Our findings demonstrate that endothelial GPR30 is a novel regulator of the inflammatory response which could be a potential therapeutic target against atherosclerosis and other inflammatory diseases.
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  • 95
    Publication Date: 2012-12-21
    Description: by Rosalinde K. E. Poortvliet, Ian Ford, Suzanne M. Lloyd, Naveed Sattar, Simon P. Mooijaart, Anton J. M. de Craen, Rudi G. J. Westendorp, J. Wouter Jukema, Christopher J. Packard, Jacobijn Gussekloo, Wouter de Ruijter, David J. Stott Variability in blood pressure predicts cardiovascular disease in young- and middle-aged subjects, but relevant data for older individuals are sparse. We analysed data from the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) study of 5804 participants aged 70–82 years with a history of, or risk factors for cardiovascular disease. Visit-to-visit variability in blood pressure (standard deviation) was determined using a minimum of five measurements over 1 year; an inception cohort of 4819 subjects had subsequent in-trial 3 years follow-up; longer-term follow-up (mean 7.1 years) was available for 1808 subjects. Higher systolic blood pressure variability independently predicted long-term follow-up vascular and total mortality (hazard ratio per 5 mmHg increase in standard deviation of systolic blood pressure = 1.2, 95% confidence interval 1.1–1.4; hazard ratio 1.1, 95% confidence interval 1.1–1.2, respectively). Variability in diastolic blood pressure associated with increased risk for coronary events (hazard ratio 1.5, 95% confidence interval 1.2–1.8 for each 5 mmHg increase), heart failure hospitalisation (hazard ratio 1.4, 95% confidence interval 1.1–1.8) and vascular (hazard ratio 1.4, 95% confidence interval 1.1–1.7) and total mortality (hazard ratio 1.3, 95% confidence interval 1.1–1.5), all in long-term follow-up. Pulse pressure variability was associated with increased stroke risk (hazard ratio 1.2, 95% confidence interval 1.0–1.4 for each 5 mmHg increase), vascular mortality (hazard ratio 1.2, 95% confidence interval 1.0–1.3) and total mortality (hazard ratio 1.1, 95% confidence interval 1.0–1.2), all in long-term follow-up. All associations were independent of respective mean blood pressure levels, age, gender, in-trial treatment group (pravastatin or placebo) and prior vascular disease and cardiovascular disease risk factors. Our observations suggest variability in diastolic blood pressure is more strongly associated with vascular or total mortality than is systolic pressure variability in older high-risk subjects.
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  • 96
    Publication Date: 2012-12-21
    Description: by Jonathan A. Hare, Mark J. Wuenschel, Matthew E. Kimball We couple a species range limit hypothesis with the output of an ensemble of general circulation models to project the poleward range limit of gray snapper. Using laboratory-derived thermal limits and statistical downscaling from IPCC AR4 general circulation models, we project that gray snapper will shift northwards; the magnitude of this shift is dependent on the magnitude of climate change. We also evaluate the uncertainty in our projection and find that statistical uncertainty associated with the experimentally-derived thermal limits is the largest contributor (∼ 65%) to overall quantified uncertainty. This finding argues for more experimental work aimed at understanding and parameterizing the effects of climate change and variability on marine species.
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  • 97
    Publication Date: 2012-12-21
    Description: by Tal Raz, Reut Avni, Yoseph Addadi, Yoni Cohen, Ariel J. Jaffa, Brian Hemmings, Joel R. Garbow, Michal Neeman In mammalian pregnancy, maternal cardiovascular adaptations must match the requirements of the growing fetus(es), and respond to physiologic and pathologic conditions. Such adaptations are particularly demanding for mammals bearing large-litter pregnancies, with their inherent conflict between the interests of each individual fetus and the welfare of the entire progeny. The mouse is the most common animal model used to study development and genetics, as well as pregnancy-related diseases. Previous studies suggested that in mice, maternal blood flow to the placentas occurs via a single arterial uterine loop generated by arterial-arterial anastomosis of the uterine artery to the uterine branch of the ovarian artery, resulting in counter bi-directional blood flow. However, we provide here experimental evidence that each placenta is actually supplied by two distinct arterial inputs stemming from the uterine artery and from the uterine branch of the ovarian artery, with position-dependent contribution of flow from each source. Moreover, we report significant positional- and inter-fetal dependent alteration of placental perfusion, which were detected by in vivo MRI and fluorescence imaging. Maternal blood flow to the placentas was dependent on litter size and was attenuated for placentas located centrally along the uterine horn. Distinctive apposing, inter-fetal hemodynamic effects of either reduced or elevated maternal blood flow, were measured for placenta of normal fetuses that are positioned adjacent to either pathological, or to hypovascular Akt1 -deficient placentas, respectively. The results reported here underscore the critical importance of confounding local and systemic in utero effects on phenotype presentation, in general and in the setting of genetically modified mice. The unique robustness and plasticity of the uterine vasculature architecture, as reported in this study, can explain the ability to accommodate varying litter sizes, sustain large-litter pregnancies and overcome pathologic challenges. Remarkably, the dual arterial supply is evolutionary conserved in mammals bearing a single offspring, including primates.
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  • 98
    Publication Date: 2012-12-21
    Description: by Zhipeng Qu, David L. Adelson ncRNAs (non-coding RNAs), in particular long ncRNAs, represent a significant proportion of the vertebrate transcriptome and probably regulate many biological processes. We used publically available ESTs (Expressed Sequence Tags) from human, mouse and zebrafish and a previously published analysis pipeline to annotate and analyze the vertebrate non-protein-coding transcriptome. Comparative analysis confirmed some previously described features of intergenic ncRNAs, such as a positionally biased distribution with respect to regulatory or development related protein-coding genes, and weak but clear sequence conservation across species. Significantly, comparative analysis of developmental and regulatory genes proximate to long ncRNAs indicated that the only conserved relationship of these genes to neighbor long ncRNAs was with respect to genes expressed in human brain, suggesting a conserved, ncRNA cis-regulatory network in vertebrate nervous system development. Most of the relationships between long ncRNAs and proximate coding genes were not conserved, providing evidence for the rapid evolution of species-specific gene associated long ncRNAs. We have reconstructed and annotated over 130,000 long ncRNAs in these three species, providing a significantly expanded number of candidates for functional testing by the research community.
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  • 99
    facet.materialart.
    Unknown
    Public Library of Science (PLoS)
    In: PLoS ONE
    Publication Date: 2012-12-21
    Description: by David J. Leibly, Trang Nhu Nguyen, Louis T. Kao, Stephen N. Hewitt, Lynn K. Barrett, Wesley C. Van Voorhis Insoluble recombinant proteins are a major issue for both structural genomics and enzymology research. Greater than 30% of recombinant proteins expressed in Escherichia coli ( E. coli) appear to be insoluble. The prevailing view is that insolubly expressed proteins cannot be easily solubilized, and are usually sequestered into inclusion bodies. However, we hypothesize that small molecules added during the cell lysis stage can yield soluble protein from insoluble protein previously screened without additives or ligands. We present a novel screening method that utilized 144 additive conditions to increase the solubility of recombinant proteins expressed in E. coli. These selected additives are natural ligands, detergents, salts, buffers, and chemicals that have been shown to increase the stability of proteins in vivo . We present the methods used for this additive solubility screen and detailed results for 41 potential drug target recombinant proteins from infectious organisms. Increased solubility was observed for 80% of the recombinant proteins during the primary and secondary screening of lysis with the additives; that is 33 of 41 target proteins had increased solubility compared with no additive controls. Eleven additives (trehalose, glycine betaine, mannitol, L-Arginine, potassium citrate, CuCl 2 , proline, xylitol, NDSB 201, CTAB and K 2 PO 4 ) solubilized more than one of the 41 proteins; these additives can be easily screened to increase protein solubility. Large-scale purifications were attempted for 15 of the proteins using the additives identified and eight (40%) were prepared for crystallization trials during the first purification attempt. Thus, this protocol allowed us to recover about a third of seemingly insoluble proteins for crystallography and structure determination. If recombinant proteins are required in smaller quantities or less purity, the final success rate may be even higher.
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  • 100
    Publication Date: 2012-11-08
    Description: by Orphal Colleye, Eric Parmentier Background Clownfishes (Pomacentridae) are brightly colored coral reef fishes well known for their mutualistic symbiosis with tropical sea anemones. These fishes live in social groups in which there is a size-based dominance hierarchy. In this structure where sex is socially controlled, agonistic interactions are numerous and serve to maintain size differences between individuals adjacent in rank. Clownfishes are also prolific callers whose sounds seem to play an important role in the social hierarchy. Here, we aim to review and to synthesize the diversity of sounds produced by clownfishes in order to emphasize the importance of acoustic signals in their way of life. Methodology/Principal Findings Recording the different acoustic behaviors indicated that sounds are divided into two main categories: aggressive sounds produced in conjunction with threat postures (charge and chase), and submissive sounds always emitted when fish exhibited head shaking movements (i.e. a submissive posture). Both types of sounds showed size-related intraspecific variation in dominant frequency and pulse duration: smaller individuals produce higher frequency and shorter duration pulses than larger ones, and inversely. Consequently, these sonic features might be useful cues for individual recognition within the group. This observation is of significant importance due to the size-based hierarchy in clownfish group. On the other hand, no acoustic signal was associated with the different reproductive activities. Conclusions/Significance Unlike other pomacentrids, sounds are not produced for mate attraction in clownfishes but to reach and to defend the competition for breeding status, which explains why constraints are not important enough for promoting call diversification in this group.
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