221 research outputs found

    Post-transcriptional regulation of the yeast high affinity iron transport system.

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    Saccharomyces cerevisiae transcriptionally regulates the expression of the plasma membrane high affinity iron transport system in response to iron need. This transport system is comprised of the products of the FET3 and FTR1 genes. We show that Fet3p and Ftr1p are post-translationally regulated by iron. Incubation of cells in high iron leads to the internalization and degradation of both Fet3p and Ftr1p. Yeast strains defective in endocytosis (Deltaend4) show a reduced iron-induced loss of Fet3p-Ftr1p. In cells with a deletion in the vacuolar protease PEP4, high iron medium leads to the accumulation of Fet3p and Ftr1p in the vacuole. Iron-induced degradation of Fet3p-Ftr1p is significantly reduced in strains containing a deletion of a gene, VTA1, which is involved in multivesicular body (MVB) sorting in yeast. Sorting through the MVB can involve ubiquitination. We demonstrate that Ftr1p is ubiquitinated, whereas Fet3p is not ubiquitinated. Iron-induced internalization and degradation of Fet3p-Ftr1p occurs in a mutant strain of the E3 ubiquitin ligase RSP5 (rsp5-1), suggesting that Rsp5p is not required. Internalization of Fet3p-Ftr1p is specific for iron and requires both an active Fet3p and Ftr1p, indicating that it is the transport of iron through the iron permease Ftr1p that is responsible for the internalization and degradation of the Fet3p-Ftr1p complex

    Hepcidin is elevated in mice injected with Mycoplasma arthritidis

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    Mycoplasma arthritidis causes arthritis in specific mouse strains. M. arthritidis mitogen (MAM), a superantigen produced by M. arthritidis, activates T cells by forming a complex between the major histocompatability complex II on antigen presenting cells and the T cell receptor on CD4+ T lymphocytes. The MAM superantigen is also known to interact with Toll-like receptors (TLR) 2 and 4. Hepcidin, an iron regulator protein, is upregulated by TLR4, IL-6, and IL-1. In this study, we evaluated serum hepcidin, transferrin saturation, ferritin, IL-6, IL-1, and hemoglobin levels in M. arthritidis injected C3H/HeJ (TLR2+/+, TLR4-/-) mice and C3H/HeSnJ (TLR2+/+, TLR4+/+) mice over a 21 day period. C3H/HeJ mice have a defective TLR4 and an inability to produce IL-6. We also measured arthritis severity in these mice and the amount of hepcidin transcripts produced by the liver and spleen. C3H/HeJ mice developed a more severe arthritis than that of C3H/HeSnJ mice. Both mice had an increase in serum hepcidin within three days after infection. Hepcidin levels were greater in C3H/HeJ mice despite a nonfunctioning TLR4 and low serum levels of IL-6. Splenic hepcidin production in C3H/HeJ mice was delayed compared to C3H/HeSnJ mice. Unlike C3H/HeSnJ mice, C3H/HeJ mice did not develop a significant rise in serum IL-6 levels but did develop a significant increase in IL-1β during the first ten days after injection. Both mice had an increase in serum ferritin but a decrease in serum transferrin saturation. In conclusion, serum hepcidin regulation in C3H/HeJ mice does not appear to be solely dependent upon TLR4 or IL-6

    Assessment of Durum Wheat (Triticum durum Desf.) Genotypes Diversity for the Integrated Production of Bioethanol and Grains

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    Wheat straw is an abundant source of lignocellulosic biomass that is generally not utilized for biofuel production, nor for other uses. Recent EU renewable energy directive fosters bioethanol production through lignocellulosic sugars fermentation, but the cost of this process is an issue that often depends on biomass characteristics. Lignin is a class of three-dimensional polymers providing structural integrity of plant tissues. Its complex structure, together with hemicelluloses and uronic acids content, could affect the ability of hydrolyzing biomass to fermentable sugars. To get insights into this variation, a set of 10 durum wheat genotypes was analyzed to determine variation of straw digestibility to fermentable sugars. The results showed that the lignin content was the major factor determining the recalcitrance to enzymatic process. The analysis of Spearman's correlation indicated that the sugar released after enzymatic hydrolysis had a negative connection with the lignin content, while it was positively correlated with the culm length. The possible role of other cell wall components, such as arabinose and uronic acids, was also discussed. This work aimed at analyzing the diversity of lignocellulosic digestibility to fermentable sugars of wheat straw in a small germplasm collection. Some of the selected genotypes were characterized by high sugars digestibility and high grain yield, characteristics that could make biorefining of wheat straw profitable

    Observation of termination-dependent topological connectivity in a magnetic Weyl Kagome lattice

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    The research leading to these results has received funding from the European Union’s Horizon 2020 research and innovation program under Marie Skłodowska-Curie Grant Agreement 897276. The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (https://www.gauss-centre.eu) for funding this project by providing computing time on the GCS Supercomputer SuperMUC-NG at Leibniz Supercomputing Centre (https://www.lrz.de). The authors are grateful for funding support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy through the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter ct.qmat (EXC 2147, Project 390858490), through FOR 5249-449872909 (Project P5), and through the Collaborative Research Center SFB 1170 ToCoTronics (Project 258499086). The authors greatly acknowledge the Diamond Light Source that supported the entire micro-ARPES experiment and corresponding costs. The Flatiron Institute is a division of the Simons Foundation. P.D.C.K. and C.B. gratefully acknowledge support from The Leverhulme Trust via Grant RL-2016-006.Engineering surfaces and interfaces of materials promises great potential in the field of heterostructures and quantum matter designers, with the opportunity to drive new many-body phases that are absent in the bulk compounds. Here, we focus on the magnetic Weyl kagome system Co3Sn2S2 and show how for the terminations of different samples the Weyl points connect differently, still preserving the bulk-boundary correspondence. Scanning tunneling microscopy has suggested such a scenario indirectly, and here, we probe the Fermiology of Co3Sn2S2 directly, by linking it to its real space surface distribution. By combining micro-ARPES and first-principles calculations, we measure the energy-momentum spectra and the Fermi surfaces of Co3Sn2S2 for different surface terminations and show the existence of topological features depending on the top-layer electronic environment. Our work helps to define a route for controlling bulk-derived topological properties by means of surface electrostatic potentials, offering a methodology for using Weyl kagome metals in responsive magnetic spintronics.Publisher PDFPeer reviewe

    A rapid diagnostic workflow for cefotaxime-resistant Escherichia coli and Klebsiella pneumoniae detection from blood cultures by MALDI-TOF mass spectrometry

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    Background: Nowadays, the global spread of resistance to oxyimino-cephalosporins in Enterobacteriaceae implies the need for novel diagnostics that can rapidly target resistant organisms from these bacterial species. Methods: In this study, we developed and evaluated a Direct Mass Spectrometry assay for Beta-Lactamase (D-MSBL) that allows direct identification of (oxyimino)cephalosporin-resistant Escherichia coli or Klebsiella pneumoniae from positive blood cultures (BCs), by using the matrix-assisted laser desorption ionization\ue2\u80\u93time of flight mass spectrometry (MALDI-TOF MS) technology. Results: The D-MSBL assay was performed on 93 E. coli or K. pneumoniae growing BC samples that were shortly co-incubated with cefotaxime (CTX) as the indicator cephalosporin. Susceptibility and resistance defining peaks from the samples\ue2\u80\u99 mass spectra were analyzed by a novel algorithm for bacterial organism classification. The D-MSBL assay allowed discrimination between E. coli and K. pneumoniae that were resistant or susceptible to CTX with a sensitivity of 86.8% and a specificity of 98.2%. Conclusion: The proposed algorithm-based D-MSBL assay, if integrated in the routine laboratory diagnostic workflow, may be useful to enhance the establishment of appropriate antibiotic therapy and to control the threat of oxyimino-cephalosporin resistance in hospital

    A global analysis of Y-chromosomal haplotype diversity for 23 STR loci

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    In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent.Peer reviewe

    Fifth European Dirofilaria and Angiostrongylus Days (FiEDAD) 2016

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    Many Labs 5:Testing pre-data collection peer review as an intervention to increase replicability

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    Replication studies in psychological science sometimes fail to reproduce prior findings. If these studies use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data-collection peer review by experts may address shortcomings and increase replicability rates. We selected 10 replication studies from the Reproducibility Project: Psychology (RP:P; Open Science Collaboration, 2015) for which the original authors had expressed concerns about the replication designs before data collection; only one of these studies had yielded a statistically significant effect (p < .05). Commenters suggested that lack of adherence to expert review and low-powered tests were the reasons that most of these RP:P studies failed to replicate the original effects. We revised the replication protocols and received formal peer review prior to conducting new replication studies. We administered the RP:P and revised protocols in multiple laboratories (median number of laboratories per original study = 6.5, range = 3?9; median total sample = 1,279.5, range = 276?3,512) for high-powered tests of each original finding with both protocols. Overall, following the preregistered analysis plan, we found that the revised protocols produced effect sizes similar to those of the RP:P protocols (?r = .002 or .014, depending on analytic approach). The median effect size for the revised protocols (r = .05) was similar to that of the RP:P protocols (r = .04) and the original RP:P replications (r = .11), and smaller than that of the original studies (r = .37). Analysis of the cumulative evidence across the original studies and the corresponding three replication attempts provided very precise estimates of the 10 tested effects and indicated that their effect sizes (median r = .07, range = .00?.15) were 78% smaller, on average, than the original effect sizes (median r = .37, range = .19?.50)

    How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons

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    COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p &lt; 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p &lt; 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p &lt; 0.0001) or urgent (20.4% vs. 38.5%; p &lt; 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p &lt; 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice
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