241 research outputs found

    Determinants of the Use of a Diabetes Risk-Screening Test

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    A study was designed to investigate why people do or do not make use of a diabetes risk test developed to facilitate the timely diagnosis of diabetes. Data were collected using a web-based questionnaire, which was based on the Health Belief Model, the Theory of Planned Behavior, and the Threatening Medical Situations Inventory. People who had and had not used the risk test were recruited to complete the survey. The sample consisted of 205 respondents: 44% who had used the test and 56% who had not. The hypothesized relationships between the dependent variable (diabetes risk test use) and the determinants used in this study were tested using logistic regression analysis. Only two significant predictors of diabetes risk test use were found: gender and barriers. More women than men use the test. Furthermore, people who experience more barriers will be less inclined to use the test. The contribution of diabetes screening tests fully depends on people’s willingness to use them. To optimize the usage of such test, it is especially important to address the barriers as perceived by the public. Two types of barriers must be addressed: practical barriers (time to take the test, fear of complexity of the test), and consequential barriers (fear of the disease and treatment, uncertainties about where to go in the case of an increased risk of diabetes)

    Extensive microbial and functional diversity within the chicken cecal microbiome

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    Chickens are major source of food and protein worldwide. Feed conversion and the health of chickens relies on the largely unexplored complex microbial community that inhabits the chicken gut, including the ceca. We have carried out deep microbial community profiling of the microbiota in twenty cecal samples via 16S rRNA gene sequences and an in-depth metagenomics analysis of a single cecal microbiota. We recovered 699 phylotypes, over half of which appear to represent previously unknown species. We obtained 648,251 environmental gene tags (EGTs), the majority of which represent new species. These were binned into over two-dozen draft genomes, which included Campylobacter jejuni and Helicobacter pullorum. We found numerous polysaccharide- and oligosaccharide-degrading enzymes encoding within the metagenome, some of which appeared to be part of polysaccharide utilization systems with genetic evidence for the co-ordination of polysaccharide degradation with sugar transport and utilization. The cecal metagenome encodes several fermentation pathways leading to the production of short-chain fatty acids, including some with novel features. We found a dozen uptake hydrogenases encoded in the metagenome and speculate that these provide major hydrogen sinks within this microbial community and might explain the high abundance of several genera within this microbiome, including Campylobacter, Helicobacter and Megamonas

    Quenched phosphorescence as alternative detection mode in the chiral separation of methotrexate by electrokinetic chromatography

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    Quenched phosphorescence was used, for the first time, as detection mode in the chiral separation of methotrexate (MTX) enantiomers by electrokinetic chromatography. The detection is based on dynamic quenching of the strong emission of the phosphorophore 1-bromo-4-naphthalene sulfonic acid (BrNS) by MTX under deoxygenated conditions. The use of a background electrolyte with 3 mg/mL 2-hydroxypropyl-β-cyclodextrin and 20% MeOH in 25 mM phosphate buffer (pH 7.0) and an applied voltage of 30 kV allowed the separation of l-MTX and its enantiomeric impurity d-MTX with sufficient resolution. In the presence of 1 mM BrNS, a detection limit of 3.2 × 10−7 M was achieved, about an order of magnitude better than published techniques based on UV absorption. The potential of the method was demonstrated with a degradation study and an enantiomeric purity assessment of l-MTX. Furthermore, l-MTX was determined in a cell culture extract as a proof-of-principle experiment to show the applicability of the method to biological samples

    A modular toolbox for gRNA-Cas9 genome engineering in plants based on the GoldenBraid standard

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    [EN] Background: The efficiency, versatility and multiplexing capacity of RNA-guided genome engineering using the CRISPR/Cas9 technology enables a variety of applications in plants, ranging from gene editing to the construction of transcriptional gene circuits, many of which depend on the technical ability to compose and transfer complex synthetic instructions into the plant cell. The engineering principles of standardization and modularity applied to DNA cloning are impacting plant genetic engineering, by increasing multigene assembly efficiency and by fostering the exchange of well-defined physical DNA parts with precise functional information. Results: Here we describe the adaptation of the RNA-guided Cas9 system to GoldenBraid (GB), a modular DNA con¿ struction framework being increasingly used in Plant Synthetic Biology. In this work, the genetic elements required for CRISPRs-based editing and transcriptional regulation were adapted to GB, and a workflow for gRNAs construction was designed and optimized. New software tools specific for CRISPRs assembly were created and incorporated to the public GB resources site. Conclusions: The functionality and the efficiency of gRNA¿Cas9 GB tools were demonstrated in Nicotiana benthamiana using transient expression assays both for gene targeted mutations and for transcriptional regulation. The availability of gRNA¿Cas9 GB toolbox will facilitate the application of CRISPR/Cas9 technology to plant genome engineeringThis work has been funded by Grant BIO2013-42193-R from Plan Nacional I + D of the Spanish Ministry of Economy and Competitiveness. Vazquez-Vilar M. is a recipient of a Junta de Ampliacion de Estudios fellowship. Bernabe-Orts J.M. is a recipient of a FPI fellowship. We want to thank Nicola J. Patron and Mark Youles for kindly providing humanCas9 and U6-26 clones. We also want to thank Eugenio Gomez for providing Arabidopsis thaliana genomic DNA and Concha Domingo for providing rice genomic DNA. We also want to thank the COST Action FA1006 for the support in the development of the software tools.Vázquez-Vilar, M.; Bernabé-Orts, JM.; Fernández Del Carmen, MA.; Ziarsolo Areitioaurtena, P.; Blanca Postigo, JM.; Granell Richart, A.; Orzáez Calatayud, DV. (2016). A modular toolbox for gRNA-Cas9 genome engineering in plants based on the GoldenBraid standard. Plant Methods. 12. https://doi.org/10.1186/s13007-016-0101-2S12Ran FA, Hsu PD, Wright J, Agarwala V, Scott DA, Zhang F. Genome engineering using the CRISPR-Cas9 system. Nat Protoc. 2013;8(11):2281–308. doi: 10.1038/nprot.2013.143 .Yang X. Applications of CRISPR-Cas9 mediated genome engineering. Mil Med Res. 2015;2:11. doi: 10.1186/s40779-015-0038-1 .Wang H, Yang H, Shivalila CS, Dawlaty MM, Cheng AW, Zhang F, et al. 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Both CRISPR/Cas-based nucleases and nickases can be used efficiently for genome engineering in Arabidopsis thaliana. Plant J. 2014;79(2):348–59. doi: 10.1111/tpj.12554 .Schiml S, Fauser F, Puchta H. The CRISPR/Cas system can be used as nuclease for in planta gene targeting and as paired nickases for directed mutagenesis in Arabidopsis resulting in heritable progeny. Plant J. 2014;80(6):1139–50. doi: 10.1111/tpj.12704 .Piatek A, Ali Z, Baazim H, Li L, Abulfaraj A, Al-Shareef S, et al. RNA-guided transcriptional regulation in planta via synthetic dCas9-based transcription factors. Plant Biotechnol J. 2015;13(4):578–89. doi: 10.1111/pbi.12284 .Beerli RR, Barbas CF 3rd. Engineering polydactyl zinc-finger transcription factors. Nat Biotechnol. 2002;20(2):135–41. doi: 10.1038/nbt0202-135 .Bogdanove AJ, Voytas DF. TAL effectors: customizable proteins for DNA targeting. Science. 2011;333(6051):1843–6. doi: 10.1126/science.1204094 .Nielsen AA, Voigt CA. Multi-input CRISPR/Cas genetic circuits that interface host regulatory networks. Mol Syst Biol. 2014;10:763. doi: 10.15252/msb.20145735 .Eeckhaut T, Lakshmanan PS, Deryckere D, Van Bockstaele E, Van Huylenbroeck J. Progress in plant protoplast research. Planta. 2013. doi: 10.1007/s00425-013-1936-7 .Mikami M, Toki S, Endo M. Comparison of CRISPR/Cas9 expression constructs for efficient targeted mutagenesis in rice. Plant Mol Biol. 2015. doi: 10.1007/s11103-015-0342-x .Patron NJ, Orzaez D, Marillonnet S, Warzecha H, Matthewman C, Youles M, et al. Standards for plant synthetic biology: a common syntax for exchange of DNA parts. New Phytol. 2015. doi: 10.1111/nph.13532 .Liu W, Stewart CN Jr. Plant synthetic biology. Trends Plant Sci. 2015;20(5):309–17. doi: 10.1016/j.tplants.2015.02.004 .Sarrion-Perdigones A, Vazquez-Vilar M, Palaci J, Castelijns B, Forment J, Ziarsolo P, et al. GoldenBraid 2.0: a comprehensive DNA assembly framework for plant synthetic biology. Plant Physiol. 2013;162(3):1618–31. doi: 10.1104/pp.113.217661 .Vazquez-Vilar M, Sarrion-Perdigones A, Ziarsolo P, Blanca J, Granell A, Orzaez D. Software-assisted stacking of gene modules using GoldenBraid 2.0 DNA-assembly framework. Methods Mol Biol. 2015;1284:399–420. doi: 10.1007/978-1-4939-2444-8_20 .Duportet X, Wroblewska L, Guye P, Li Y, Eyquem J, Rieders J, et al. A platform for rapid prototyping of synthetic gene networks in mammalian cells. Nucleic Acids Res. 2014;42(21):13440–51. doi: 10.1093/nar/gku1082 .Guo Y, Dong J, Zhou T, Auxillos J, Li T, Zhang W, et al. YeastFab: the design and construction of standard biological parts for metabolic engineering in Saccharomyces cerevisiae. Nucleic Acids Res. 2015;43(13):e88. doi: 10.1093/nar/gkv464 .Engler C, Gruetzner R, Kandzia R, Marillonnet S. Golden gate shuffling: a one-pot DNA shuffling method based on type IIs restriction enzymes. PLoS ONE. 2009;4(5):e5553. doi: 10.1371/journal.pone.0005553 .Sarrion-Perdigones A, Falconi EE, Zandalinas SI, Juarez P, Fernandez-del-Carmen A, Granell A, et al. GoldenBraid: an iterative cloning system for standardized assembly of reusable genetic modules. PLoS ONE. 2011;6(7):e21622. doi: 10.1371/journal.pone.0021622 .Lei Y, Lu L, Liu HY, Li S, Xing F, Chen LL. CRISPR-P: a web tool for synthetic single-guide RNA design of CRISPR-system in plants. Mol Plant. 2014;7(9):1494–6. doi: 10.1093/mp/ssu044 .Mali P, Yang L, Esvelt KM, Aach J, Guell M, DiCarlo JE, et al. RNA-guided human genome engineering via Cas9. Science. 2013;339(6121):823–6. doi: 10.1126/science.1232033 .Li JF, Norville JE, Aach J, McCormack M, Zhang D, Bush J, et al. Multiplex and homologous recombination-mediated genome editing in Arabidopsis and Nicotiana benthamiana using guide RNA and Cas9. Nat Biotechnol. 2013;31(8):688–91. doi: 10.1038/nbt.2654 .Bikard D, Jiang W, Samai P, Hochschild A, Zhang F, Marraffini LA. Programmable repression and activation of bacterial gene expression using an engineered CRISPR-Cas system. Nucleic Acids Res. 2013;41(15):7429–37. doi: 10.1093/nar/gkt520 .Xie K, Minkenberg B, Yang Y. Boosting CRISPR/Cas9 multiplex editing capability with the endogenous tRNA-processing system. Proc Natl Acad Sci USA. 2015;112(11):3570–5. doi: 10.1073/pnas.1420294112 .Weber E, Engler C, Gruetzner R, Werner S, Marillonnet S. A modular cloning system for standardized assembly of multigene constructs. PLoS ONE. 2011;6(2):e16765. doi: 10.1371/journal.pone.0016765 .Sakuma T, Nishikawa A, Kume S, Chayama K, Yamamoto T. Multiplex genome engineering in human cells using all-in-one CRISPR/Cas9 vector system. Sci Rep. 2014;4:5400. doi: 10.1038/srep05400 .Ma X, Zhang Q, Zhu Q, Liu W, Chen Y, Qiu R, et al. A robust CRISPR/Cas9 system for convenient, high-efficiency multiplex genome editing in monocot and dicot plants. 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    Annelid phylogeny and the status of Sipuncula and Echiura

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    BACKGROUND: Annelida comprises an ancient and ecologically important animal phylum with over 16,500 described species and members are the dominant macrofauna of the deep sea. Traditionally, two major groups are distinguished: Clitellata (including earthworms, leeches) and "Polychaeta" (mostly marine worms). Recent analyses of molecular data suggest that Annelida may include other taxa once considered separate phyla (i.e., Echiura, and Sipuncula) and that Clitellata are derived annelids, thus rendering "Polychaeta" paraphyletic; however, this contradicts classification schemes of annelids developed from recent analyses of morphological characters. Given that deep-level evolutionary relationships of Annelida are poorly understood, we have analyzed comprehensive datasets based on nuclear and mitochondrial genes, and have applied rigorous testing of alternative hypotheses so that we can move towards the robust reconstruction of annelid history needed to interpret animal body plan evolution. RESULTS: Sipuncula, Echiura, Siboglinidae, and Clitellata are all nested within polychaete annelids according to phylogenetic analyses of three nuclear genes (18S rRNA, 28S rRNA, EF1α; 4552 nucleotide positions analyzed) for 81 taxa, and 11 nuclear and mitochondrial genes for 10 taxa (additional: 12S rRNA, 16S rRNA, ATP8, COX1-3, CYTB, NAD6; 11,454 nucleotide positions analyzed). For the first time, these findings are substantiated using approximately unbiased tests and non-scaled bootstrap probability tests that compare alternative hypotheses. For echiurans, the polychaete group Capitellidae is corroborated as the sister taxon; while the exact placement of Sipuncula within Annelida is still uncertain, our analyses suggest an affiliation with terebellimorphs. Siboglinids are in a clade with other sabellimorphs, and clitellates fall within a polychaete clade with aeolosomatids as their possible sister group. None of our analyses support the major polychaete clades reflected in the current classification scheme of annelids, and hypothesis testing significantly rejects monophyly of Scolecida, Palpata, Canalipalpata, and Aciculata. CONCLUSION: Using multiple genes and explicit hypothesis testing, we show that Echiura, Siboglinidae, and Clitellata are derived annelids with polychaete sister taxa, and that Sipuncula should be included within annelids. The traditional composition of Annelida greatly underestimates the morphological diversity of this group, and inclusion of Sipuncula and Echiura implies that patterns of segmentation within annelids have been evolutionarily labile. Relationships within Annelida based on our analyses of multiple genes challenge the current classification scheme, and some alternative hypotheses are provided

    Effects of Helicobacter suis γ-glutamyl transpeptidase on lymphocytes: modulation by glutamine and glutathione supplementation and outer membrane vesicles as a putative delivery route of the enzyme

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    Helicobacter (H.) suis colonizes the stomach of the majority of pigs as well as a minority of humans worldwide. Infection causes chronic inflammation in the stomach of the host, however without an effective clearance of the bacteria. Currently, no information is available about possible mechanisms H. suis utilizes to interfere with the host immune response. This study describes the effect on various lymphocytes of the γ-glutamyl transpeptidase (GGT) from H. suis. Compared to whole cell lysate from wild-type H. suis, lysate from a H. suis ggt mutant strain showed a decrease of the capacity to inhibit Jurkat T cell proliferation. Incubation of Jurkat T cells with recombinantly expressed H. suis GGT resulted in an impaired proliferation, and cell death was shown to be involved. A similar but more pronounced inhibitory effect was also seen on primary murine CD4+ T cells, CD8+ T cells, and CD19+ B cells. Supplementation with known GGT substrates was able to modulate the observed effects. Glutamine restored normal proliferation of the cells, whereas supplementation with reduced glutathione strengthened the H. suis GGT-mediated inhibition of proliferation. H. suis GGT treatment abolished secretion of IL-4 and IL-17 by CD4+ T cells, without affecting secretion of IFN-γ. Finally, H. suis outer membrane vesicles (OMV) were identified as a possible delivery route of H. suis GGT to lymphocytes residing in the deeper mucosal layers. Thus far, this study is the first to report that the effects on lymphocytes of this enzyme, not only important for H. suis metabolism but also for that of other Helicobacter species, depend on the degradation of two specific substrates: glutamine and reduced glutatione. This will provide new insights into the pathogenic mechanisms of H. suis infection in particular and infection with gastric helicobacters in general
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