177 research outputs found

    The C1q binding activity of IgG is modified in vitro by reactive oxygen species: implications for rheumatoid arthritis

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    AbstractIgG can be denatured in vitro by reactive oxygen species (ROS). Native IgG activates the complement cascade through C1q. Using a modified ELISA, C1q binding activity of rheumatoid IgG has been compared to IgG denatured by neutrophil-derived ROS. The C1q binding activity of rheumatoid synovial fluid IgG is greater than the corresponding serum IgG (P < 0.01). Denaturation of IgG by activated polymorphs or the Fenton reaction decreased its C1q binding activity (P < 0.01). In vitro exposure of IgG to OH· and ROO· increased its interaction with C1q (P < 0.01). Hypochlorous acid had no effect. ROS-induced alteration to IgG-C1q binding activity may promote the inflammatory response in rheumatoid arthritis

    Lipid (per) oxidation in mitochondria: an emerging target in the ageing process?

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    Lipids are essential for physiological processes such as maintaining membrane integrity, providing a source of energy and acting as signalling molecules to control processes including cell proliferation, metabolism, inflammation and apoptosis. Disruption of lipid homeostasis can promote pathological changes that contribute towards biological ageing and age-related diseases. Several age-related diseases have been associated with altered lipid metabolism and an elevation in highly damaging lipid peroxidation products; the latter has been ascribed, at least in part, to mitochondrial dysfunction and elevated ROS formation. In addition, senescent cells, which are known to contribute significantly to age-related pathologies, are also associated with impaired mitochondrial function and changes in lipid metabolism. Therapeutic targeting of dysfunctional mitochondrial and pathological lipid metabolism is an emerging strategy for alleviating their negative impact during ageing and the progression to age-related diseases. Such therapies could include the use of drugs that prevent mitochondrial uncoupling, inhibit inflammatory lipid synthesis, modulate lipid transport or storage, reduce mitochondrial oxidative stress and eliminate senescent cells from tissues. In this review, we provide an overview of lipid structure and function, with emphasis on mitochondrial lipids and their potential for therapeutic targeting during ageing and age-related disease

    Hypertension and albuminuria in chronic kidney disease mapped to a mouse chromosome 11 locus

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    Chronic kidney disease (CKD) is a key cause of hypertension and a potent independent risk for cardiovascular disease. Epidemiological studies suggest a strong genetic component determining susceptibility for renal disease and, by inference, the associated cardiovascular risk. With a subtotal nephrectomy model of kidney disease, we found the 129S6 mouse strain to be very susceptible to the development of hypertension, albuminuria, and kidney injury, whereas the C57BL/6 strain is relatively resistant. Accordingly, we set out to map quantitative trait loci conferring susceptibility to hypertension and albuminuria using this model with F2 mice. We found significant linkage of the blood pressure trait to two loci. At D11Mit143, mice homozygous for the 129S6 allele had significantly higher systolic blood pressure than mice heterozygous or homozygous for the C57BL/6 allele. Similarly, at D1Mit308, there was an excellent correlation between genotype and the blood pressure phenotype. The effect of the chromosome 11 locus was verified with a separate cohort of F2 mice. For the albuminuria trait, a significant locus was found at D11Mit143, which overlaps the blood pressure trait locus. Our studies have identified a region spanning ∌8 cM on mouse chromosome 11 that is associated with susceptibility to hypertension and albuminuria in CKD

    Novel ageing-biomarker discovery using data-intensive technologies

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    Ageing is accompanied by many visible characteristics. Other biological and physiological markers are also well-described e.g. loss of circulating sex hormones and increased inflammatory cytokines. Biomarkers for healthy ageing studies are presently predicated on existing knowledge of ageing traits. The increasing availability of data-intensive methods enables deep-analysis of biological samples for novel biomarkers. We have adopted two discrete approaches in MARK-AGE Work Package 7 for biomarker discovery; (1) microarray analyses and/or proteomics in cell systems e.g. endothelial progenitor cells or T cell ageing including a stress model; and (2) investigation of cellular material and plasma directly from tightly-defined proband subsets of different ages using proteomic, transcriptomic and miR array. The first approach provided longitudinal insight into endothelial progenitor and T cell ageing.This review describes the strategy and use of hypothesis-free, data-intensive approaches to explore cellular proteins, miR, mRNA and plasma proteins as healthy ageing biomarkers, using ageing models and directly within samples from adults of different ages. It considers the challenges associated with integrating multiple models and pilot studies as rational biomarkers for a large cohort study. From this approach, a number of high-throughput methods were developed to evaluate novel, putative biomarkers of ageing in the MARK-AGE cohort

    ISML: an interface specification meta-language

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    In this paper we present an abstract metaphor model situated within a model-based user interface framework. The inclusion of metaphors in graphical user interfaces is a well established, but mostly craft-based strategy to design. A substantial body of notations and tools can be found within the model-based user interface design literature, however an explicit treatment of metaphor and its mappings to other design views has yet to be addressed. We introduce the Interface Specification Meta-Language (ISML) framework and demonstrate its use in comparing the semantic and syntactic features of an interactive system. Challenges facing this research are outlined and further work proposed

    Differentiating normal and problem gambling: a grounded theory approach.

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    A previous study (Ricketts &amp; Macaskill, 2003) delineated a theory of problem gambling based on the experiences of treatment seeking male gamblers and allowed predictions to be made regarding the processes that differentiate between normal and problem gamblers. These predictions are the focus of the present study, which also utilised a grounded theory approach, but with a sample of male high frequency normal gamblers. The findings suggest that there are common aspects of gambling associated with arousal and a sense of achievement. The use of gambling to manage negative emotional states differentiated normal and problem gambling. Perceived self-efficacy , emotion management skills and perceived likelihood of winning money back were intervening variables differentiating problem and normal gamblers.</p

    Phospholipid oxidation and carotenoid supplementation in Alzheimer’s disease patients

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    Alzheimer's disease (AD) is a progressive, neurodegenerative disease, characterised by decline of memory, cognitive function and changes in behaviour. Generic markers of lipid peroxidation are increased in AD, therefore reactive oxygen species have been suggested to be involved in the aetiology of cognitive decline. Carotenoids are depleted in AD serum, therefore we have compared serum lipid oxidation between AD and age-matched control subjects before and after carotenoid supplementation. The novel oxidised phospholipid biomarker 1-palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC) was analysed using electrospray ionization tandem mass spectrometry (MS) with multiple reaction monitoring (MRM), 8-isoprostane (IsoP) was measured by ELISA and ferric reducing antioxidant potential (FRAP) was measured by a colorimetric assay. AD patients (n=21) and healthy age-matched control subjects (n=16) were supplemented with either Macushieldℱ (10 mg meso-zeaxanthin, 10 mg lutein, 2 mg zeaxanthin) or placebo (sunflower oil) for six months. The MRM-MS method determined serum POVPC sensitively (from 10 ”l serum) and reproducibly (CV=7.9%). At baseline, AD subjects had higher serum POVPC compared to age-matched controls, (p=0.017) and cognitive function was correlated inversely with POVPC (r=−0.37; p=0.04). After six months of carotenoid intervention, serum POVPC was not different in AD patients compared to healthy controls. However, POVPC was significantly higher in control subjects after six months of carotenoid intervention compared to their baseline (p=0.03). Serum IsoP concentration was unrelated to disease or supplementation. Serum FRAP was significantly lower in AD than healthy controls but was unchanged by carotenoid intervention (p=0.003). In conclusion, serum POVPC is higher in AD patients compared to control subjects, is not reduced by carotenoid supplementation and correlates with cognitive function

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

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    A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters
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