435 research outputs found

    Rheumatoid peripheral blood phagocytes are primed for activation but have impaired Fc-mediated generation of reactive oxygen species

    Get PDF
    Significant levels of circulating immune complexes (ICs) containing rheumatoid factors and immunoglobulin G in peripheral blood are a characteristic feature of rheumatoid arthritis (RA). ICs interact through FcĪ³ receptors (FcĪ³R) to activate phagocytes in numerous inflammatory processes. The high concentration of neutrophils in synovial fluid during active phases of the disease, together with their destructive capacity, pose important questions as to their role in the pathogenesis of RA. Functional defects in RA or control peripheral blood neutrophil FcĪ³Rs were examined with a specific FcĪ³R-mediated reactive oxygen species (ROS) assay. Heterologous cross-linking of FcĪ³RIIa and FcĪ³RIIIb on neutrophils resulted in a significantly decreased production of ROS by RA cells compared with controls matched for age and sex. However, expression and homologous ligation of receptors did not differ between these groups. These data suggest that neutrophil priming does occur before emigration into the joint and that blood neutrophils from patients with RA have a functional impairment in cooperative FcĪ³R-mediated ROS generation. This may account for the increased susceptibility to bacterial infection that arises in patients with severe disease

    Council housing: Time to invest (now, more than ever), submission of evidence to the All Party Parliamentary Group for Council Housing

    Get PDF
    In 2010, the Parliamentary Council Housing Group of MPs and Defend Council Housing (DCH) published ā€œCouncil Housing: Time to Invest, fair funding, investment and building council housingā€. It was the result of an Inquiry that took evidence from tenants, councillors and others, and combined this in a thoroughly researched analysis of existing government policy, concluding that direct investment in council housing, accountably managed and maintained, was essential to produce and maintain the genuinely affordable and secure homes we have and need. But the 2012 ā€˜self-financingā€™ regime which promised new financial resources for Council housing, has not delivered. Councils have attempted to find alternative sources of much-needed investment, looking to Special Purpose Vehicles, Joint Ventures and Local Housing Companies. These have not brought solutions to the scale of the UKā€™s housing crisis, which continues to deepen. A lot has changed since 2010, and the pressures on council housing have only increased. Grenfell is a deadly symptom of what has gone wrong with UK housing policy. And the false economy of current policy is illustrated by the billions of pounds councils are having to spend on temporary accommodation. We are therefore glad to help in updating research to assess the current situation and the different investment strategies offered as an alternative to direct investment. MPs will be calling for evidence, and discussing these issues, with tenants, campaigners, trade unions and councillors around the country. This paper is intended as a starting point for that discussion, outlining relevant past and current policies and assessing what we know about their effectiveness and possible consequences

    Permissive and Restricted Virus Infection of Murine Embryonic Stem Cells

    Get PDF
    Recent RNA interference (RNAi) studies have identified many host proteins that modulate virus infection, but small interfering RNA 'off-target' effects and the use of transformed cell lines limit their conclusiveness. As murine embryonic stem (mES) cells can be genetically modified and resources exist where many and eventually all known mouse genes are insertionally inactivated, it was reasoned that mES cells would provide a useful alternative to RNAi screens. Beyond allowing investigation of host-pathogen interactions in vitro, mES cells have the potential to differentiate into other primary cell types, as well as being used to generate knockout mice for in vivo studies. However, mES cells are poorly characterized for virus infection. To investigate whether ES cells can be used to explore host-virus interactions, this study characterized the responses of mES cells following infection by herpes simplex virus type 1 (HSV-1) and influenza A virus. HSV-1 replicated lytically in mES cells, although mES cells were less permissive than most other cell types tested. Influenza virus was able to enter mES cells and express some viral proteins, but the replication cycle was incomplete and no infectious virus was produced. Knockdown of the host protein AHCYL1 in mES cells reduced HSV-1 replication, showing the potential for using mES cells to study host-virus interactions. Transcriptional profiling, however, indicated the lack of an efficient innate immune response in these cells. mES cells may thus be useful to identify host proteins that play a role in virus replication, but they are not suitable to determine factors that are involved in innate host defence

    Regulation and localization of endogenous human tristetraprolin

    Get PDF
    Tumor necrosis factor (TNF) has been implicated in the development and pathogenicity of infectious diseases and autoimmune disorders, such as septic shock and arthritis. The zinc-finger protein tristetraprolin (TTP) has been identified as a major regulator of TNF biosynthesis. To define its intracellular location and examine its regulation of TNF, a quantitive intracellular staining assay specific for TTP was developed. We establish for the first time that in peripheral blood leukocytes, expression of endogenous TTP is confined to the cytoplasm. Baseline expression of TTP was higher in monocytes than in lymphocytes or neutrophils. After in vitro incubation with lipopolysaccharide (LPS), leukocyte TTP levels increased rapidly, peaking after approximately 2 hours. Monocytes showed the greatest response to LPS stimulation and lymphocytes the least. TTP levels were also studied in leukocytes isolated from healthy volunteers infused with a bolus dose of LPS. TTP expression and initial upregulation in response to LPS infusion were consistent with the in vitro data. Neutrophil TTP levels responded first, reaching an initial peak within 1 hour, monocyte levels peaked next at 2 hours, followed by lymphocytes at 4 hours. This response paralleled plasma TNF levels, which peaked 2 hours after infusion and were no longer detectable after 12 hours. A second rise in intracellular TTP levels, which did not parallel plasma TNF levels, was observed in all leukocyte populations, starting 12 hours after infusion. These data establish the cytoplasmic location of TTP, supporting a major role for this protein in regulating TNF production, and suggest that TTP levels are not regulated solely by TNF

    HyCon - a virtual reality design support tool for hybrid concrete structural frames

    Get PDF
    Hybrid concrete can provide high quality, cost effective structural frames in a variety of situations when compared to other, more conventional, solutions such as in-situ concrete and steel frames. The key players in the design and construction supply chain process for hybrid concrete are lead frame contractors and design engineers. The use of hybrid concrete, however, is sometimes not considered by contractors and designers during the initial stages of design. This is often because of a lack of reliable and accessible hybrid concrete cost and production time information. Without this information, contractors and designers may disregard hybrid concrete as a design alternative, potentially omitting the most appropriate solution before it has even been considered. This paper reports on a collaborative research project in the United Kingdom which has developed HyCon - a prototype design support tool which allows contractors and designers at the conceptual design stage to carry out "what if?" analysis in a virtual reality environment to consider various hybrid concrete alternatives against a range of 'hard' and 'soft' performance criteria. The 'hard' criteria allow contractors and designers to assess initial and whole life cycle cost and production duration implications. The 'soft' criteria encourage the whole project team to assess and prioritise the importance and performance of design alternatives against criteria such as physical form and space

    First Data Release of the Hyper Suprime-Cam Subaru Strategic Program

    Full text link
    The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is a three-layered imaging survey aimed at addressing some of the most outstanding questions in astronomy today, including the nature of dark matter and dark energy. The survey has been awarded 300 nights of observing time at the Subaru Telescope and it started in March 2014. This paper presents the first public data release of HSC-SSP. This release includes data taken in the first 1.7 years of observations (61.5 nights) and each of the Wide, Deep, and UltraDeep layers covers about 108, 26, and 4 square degrees down to depths of i~26.4, ~26.5, and ~27.0 mag, respectively (5sigma for point sources). All the layers are observed in five broad bands (grizy), and the Deep and UltraDeep layers are observed in narrow bands as well. We achieve an impressive image quality of 0.6 arcsec in the i-band in the Wide layer. We show that we achieve 1-2 per cent PSF photometry (rms) both internally and externally (against Pan-STARRS1), and ~10 mas and 40 mas internal and external astrometric accuracy, respectively. Both the calibrated images and catalogs are made available to the community through dedicated user interfaces and database servers. In addition to the pipeline products, we also provide value-added products such as photometric redshifts and a collection of public spectroscopic redshifts. Detailed descriptions of all the data can be found online. The data release website is https://hsc-release.mtk.nao.ac.jp/.Comment: 34 pages, 20 figures, 7 tables, moderate revision, accepted for publication in PAS
    • ā€¦
    corecore