251 research outputs found

    A study of the association of HLA DR, DQ, and complement C4 alleles with systemic lupus erythematosus in Iceland

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldOBJECTIVE: To perform an exploratory analysis of the relative contribution of single MHC genes to the pathogenesis of systemic lupus erythematosus (SLE) in a homogenous white population. METHODS: MHC class II alleles and C4 allotypes were determined in 64 SLE patients and in ethnically matched controls. HLA-DR and DQ typing was performed by polymerase chain reaction amplification with sequence specific primers. C4 allotypes were determined by agarose gel electrophoresis. RESULTS: The frequency of C4A*Q0 was significantly higher in patients than in controls (46.9% v 25.3%, p = 0.002). HLA-DRB1, DQA1, and DQB1 alleles in the whole group of SLE patients were not significantly different from those of controls. On the other hand increase in DRB1*03 was observed in the group of patients with C4A*Q0, as compared with patients with other C4A allotypes (p = 0.047). There was no significant correlation between severe and mild disease, as judged by the SLEDAI, and HLADR, DQ alleles and comparing the patients with C4A*Q0 with those with other C4A allotypes there was no significant difference regarding clinical manifestations. CONCLUSION: The results are consistent with the argument that C4A deficiency contributes independently to susceptibility and the pathogenesis of SLE. C4A*Q0 in SLE patients in Iceland shows weaker linkage disequilibrium with DR3 genes than reported in most other white populations and emphasises the role of ethnicity

    Fate specification and tissue-specific cell cycle control of the <i>Caenorhabditis elegans</i> intestine

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    Coordination between cell fate specification and cell cycle control in multicellular organisms is essential to regulate cell numbers in tissues and organs during development, and its failure may lead to oncogenesis. In mammalian cells, as part of a general cell cycle checkpoint mechanism, the F-box protein β-transducin repeat-containing protein (β-TrCP) and the Skp1/Cul1/F-box complex control the periodic cell cycle fluctuations in abundance of the CDC25A and B phosphatases. Here, we find that the Caenorhabditis elegans β-TrCP orthologue LIN-23 regulates a progressive decline of CDC-25.1 abundance over several embryonic cell cycles and specifies cell number of one tissue, the embryonic intestine. The negative regulation of CDC-25.1 abundance by LIN-23 may be developmentally controlled because CDC-25.1 accumulates over time within the developing germline, where LIN-23 is also present. Concurrent with the destabilization of CDC-25.1, LIN-23 displays a spatially dynamic behavior in the embryo, periodically entering a nuclear compartment where CDC-25.1 is abundant

    IEA EBC Annex 57 ‘Evaluation of Embodied Energy and CO<sub>2eq</sub> for Building Construction'

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    The current regulations to reduce energy consumption and greenhouse gas emissions (GHG) from buildings have focused on operational energy consumption. Thus legislation excludes measurement and reduction of the embodied energy and embodied GHG emissions over the building life cycle. Embodied impacts are a significant and growing proportion and it is increasingly recognized that the focus on reducing operational energy consumption needs to be accompanied by a parallel focus on reducing embodied impacts. Over the last six years the Annex 57 has addressed this issue, with researchers from 15 countries working together to develop a detailed understanding of the multiple calculation methods and the interpretation of their results. Based on an analysis of 80 case studies, Annex 57 showed various inconsistencies in current methodological approaches, which inhibit comparisons of results and difficult development of robust reduction strategies. Reinterpreting the studies through an understanding of the methodological differences enabled the cases to be used to demonstrate a number of important strategies for the reduction of embodied impacts. Annex 57 has also produced clear recommendations for uniform definitions and templates which improve the description of system boundaries, completeness of inventory and quality of data, and consequently the transparency of embodied impact assessments

    Density, adhesion and stiffness of warm mix asphalts

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    XI Congreso de Ingeniería del Transporte (CIT 2014)This study presents the results of different laboratory tests related to the density, adhesion (sensitivity to water test) and rigidity (resilient module) of bituminous mixtures, manufactured at three different temperatures (160 °C, 140 °C and 120 °C), with three additives: a surfactant made up of different amino substances, a paraffin obtained by the Fisher-Tropsch synthesis process which is totally soluble in bitumen, and a synthetic zeolite in powder form which causes the bitumen to micro-foam,. Test samples have been compacted by impact, according to the Marshall method, and kneading, according to gyratory machine. To evaluate these properties an asphalt concrete mixture has been chosen, with a binder, B-50/70, and a maximum size of aggregates of 16 mm, which is usually placed in the surface layer of the pavement. The densities obtained by the two compaction methods are easy to reach. Densities will decrease if the temperature of manufacturing is lower. All mixtures compacted by gyratory machine at different temperatures displayed very good behavior of water sensitivity; but not all mixtures compacted by impact achieved this. The additives improve the adhesion between aggregate and binder. The stiffness moduli decreased in all mixtures for both types of compaction when the temperature was higher, and this reduction is less pronounced in the mixes manufactured with the gyratory compactor. Mixtures with additives tend to reduce the module, except paraffin.This paper is based on the results for the Fenix Project. The development of the Fenix Project was possible thanks to the financial contribution of the Center for Technological and Industrial Development (CDTI) within the framework of the Ingenio 2010 programme, through the CENIT Programme

    STK295900, a Dual Inhibitor of Topoisomerase 1 and 2, Induces G<inf>2</inf> Arrest in the Absence of DNA Damage

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    STK295900, a small synthetic molecule belonging to a class of symmetric bibenzimidazoles, exhibits antiproliferative activity against various human cancer cell lines from different origins. Examining the effect of STK295900 in HeLa cells indicates that it induces G2 phase arrest without invoking DNA damage. Further analysis shows that STK295900 inhibits DNA relaxation that is mediated by topoisomerase 1 (Top 1) and topoisomerase 2 (Top 2) in vitro. In addition, STK295900 also exhibits protective effect against DNA damage induced by camptothecin. However, STK295900 does not affect etoposide-induced DNA damage. Moreover, STK295900 preferentially exerts cytotoxic effect on cancer cell lines while camptothecin, etoposide, and Hoechst 33342 affected both cancer and normal cells. Therefore, STK295900 has a potential to be developed as an anticancer chemotherapeutic agent. © 2013 Kim et al

    Arylstibonic acids are potent and isoform-selective inhibitors of Cdc25a and Cdc25b phosphatases

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    Arylstibonates structurally resemble phosphotyrosine side chains in proteins and here we addressed the ability of such compounds to act as inhibitors of a panel of mammalian tyrosine and dual-specificity phosphatases. Two arylstibonates both possessing a carboxylate side chain were identified as potent inhibitors of the protein tyrosine phosphatase PTP-β. In addition, they inhibited the dual-specificity, cell cycle regulatory phosphatases Cdc25a and Cdc25b with sub-micromolar potency. However, the Cdc25c phosphatase was not affected demonstrating that arylstibonates may be viable leads from which to develop isoform specific Cdc25 inhibitors

    Interferon regulatory factor 5 (IRF5) gene variants are associated with multiple sclerosis in three distinct populations

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    Background: IRF5 is a transcription factor involved both in the type I interferon and the toll-like receptor signalling pathways. Previously, IRF5 has been found to be associated with systemic lupus erythematosus, rheumatoid arthritis and inflammatory bowel diseases. Here we investigated whether polymorphisms in the IRF5 gene would be associated with yet another disease with features of autoimmunity, multiple sclerosis (MS). Methods: We genotyped nine single nucleotide polymorphisms and one insertion-deletion polymorphism in the IRF5 gene in a collection of 2337 patients with MS and 2813 controls from three populations: two case-control cohorts from Spain and Sweden, and a set of MS trio families from Finland. Results: Two single nucleotide polymorphism (SNPs) (rs4728142, rs3807306), and a 5 bp insertion-deletion polymorphism located in the promoter and first intron of the IRF5 gene, showed association signals with values of p<0.001 when the data from all cohorts were combined. The predisposing alleles were present on the same common haplotype in all populations. Using electrophoretic mobility shift assays we observed allele specific differences in protein binding for the SNP rs4728142 and the 5 bp indel, and by a proximity ligation assay we demonstrated increased binding of the transcription factor SP1 to the risk allele of the 5 bp indel. Conclusion: These findings add IRF5 to the short list of genes shown to be associated with MS in more than one population. Our study adds to the evidence that there might be genes or pathways that are common in multiple autoimmune diseases, and that the type I interferon system is likely to be involved in the development of these diseases.Peer Reviewe

    No evidence of association between genetic variants of the PDCD1 ligands and SLE

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldPDCD1, an immunoreceptor involved in peripheral tolerance has previously been shown to be genetically associated with systemic lupus erythematosus (SLE). PDCD1 has two ligands whose genes are located in close proximity on chromosome 9p24. Our attention was drawn to these ligands after finding suggestive linkage to a marker (gata62f03, Z=2.27) located close to their genes in a genome scan of Icelandic families multiplex for SLE. Here, we analyse Swedish trios (N=149) for 23 single nucleotide polymorphisms (SNPs) within the genes of the PDCD1 ligands. Initially, indication of association to eight SNPs was observed, and these SNPs were therefore also analysed in Mexican trios (N=90), as well as independent sets of patients and controls from Sweden (152 patients, 448 controls) and Argentina (288 patients, 288 controls). We do not find support for genetic association to SLE. This is the first genetic study of SLE and the PDCD1 ligands and the lack of association in several cohorts implies that these genes are not major risk factors for SLE.Genes and Immunity (2007) 8, 69-74. doi:10.1038/sj.gene.6364360; published online 30 November 2006

    The Splicing Efficiency of Activating HRAS Mutations Can Determine Costello Syndrome Phenotype and Frequency in Cancer

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    Costello syndrome (CS) may be caused by activating mutations in codon 12/13 of the HRAS proto-oncogene. HRAS p.Gly12Val mutations have the highest transforming activity, are very frequent in cancers, but very rare in CS, where they are reported to cause a severe, early lethal, phenotype. We identified an unusual, new germline p.Gly12Val mutation, c.35_36GC>TG, in a 12-year-old boy with attenuated CS. Analysis of his HRAS cDNA showed high levels of exon 2 skipping. Using wild type and mutant HRAS minigenes, we confirmed that c.35_36GC>TG results in exon 2 skipping by simultaneously disrupting the function of a critical Exonic Splicing Enhancer (ESE) and creation of an Exonic Splicing Silencer (ESS). We show that this vulnerability of HRAS exon 2 is caused by a weak 3' splice site, which makes exon 2 inclusion dependent on binding of splicing stimulatory proteins, like SRSF2, to the critical ESE. Because the majority of cancer- and CS- causing mutations are located here, they affect splicing differently. Therefore, our results also demonstrate that the phenotype in CS and somatic cancers is not only determined by the different transforming potentials of mutant HRAS proteins, but also by the efficiency of exon 2 inclusion resulting from the different HRAS mutations. Finally, we show that a splice switching oligonucleotide (SSO) that blocks access to the critical ESE causes exon 2 skipping and halts proliferation of cancer cells. This unravels a potential for development of new anti-cancer therapies based on SSO-mediated HRAS exon 2 skipping

    Comparative Long-term Adverse Effects Elicited by Invasive Group B and C Meningococcal Infections

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    No vaccine is universally active against serogroup B meningococci. A theoretical concern that serogroup B capsular polysaccharide may induce autoimmunity hampers vaccine development. We studied long-term complications in 120 survivors of meningococcal disease. No evidence of increased autoimmune, neurological, or psychiatric disease was noted
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