457 research outputs found

    Lower limb arterial calcification (LLAC) scores in patients with symptomatic peripheral arterial disease are associated with increased cardiac mortality and morbidity

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    Aims The association of coronary arterial calcification with cardiovascular morbidity and mortality is well-recognized. Lower limb arterial calcification (LLAC) is common in PAD but its impact on subsequent health is poorly described. We aimed to determine the association between a LLAC score and subsequent cardiovascular events in patients with symptomatic peripheral arterial disease (PAD). Methods LLAC scoring, and the established Bollinger score, were derived from a database of unenhanced CT scans, from patients presenting with symptomatic PAD. We determined the association between these scores outcomes. The primary outcome was combined cardiac mortality and morbidity (CM/M) with a secondary outcome of all-cause mortality. Results 220 patients (66% male; median age 69 years) were included with follow-up for a median 46 [IQR 31–64] months. Median total LLAC scores were higher in those patients suffering a primary outcome (6831 vs. 1652; p = 0.012). Diabetes mellitus (p = 0.039), ischaemic heart disease (p = 0.028), chronic kidney disease (p = 0.026) and all-cause mortality (p = 0.012) were more common in patients in the highest quartile of LLAC scores. The area under the curve of the receiver operator curve for the LLAC score was greater (0.929: 95% CI [0.884–0.974]) than for the Bollinger score (0.824: 95% CI [0.758–0.890]) for the primary outcome. A LLAC score ≥ 4400 had the best diagnostic accuracy to determine the outcome measure. Conclusion This is the largest study to investigate links between lower limb arterial calcification and cardiovascular events in symptomatic PAD. We describe a straightforward, reproducible, CT-derived measure of calcification—the LLAC score.M.M.C. is supported by the Royal College of Surgeons of England Fellowship Programme and a British Heart Foundation Research Fellowship award FS/16/29/31957. J.M.T. is supported by a Wellcome Trust Research Training Fellowship (104492/Z/14/Z). J.H.F.R. is part-supported by the NIHR Cambridge Biomedical Research Centre, the British Heart Foundation, HEFCE and the Wellcome Trust

    Sphalerons and the Electroweak Phase Transition in Models with Higher Scalar Representations

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    In this work we investigate the sphaleron solution in a SU(2)×U(1)XSU(2)\times U(1)_X gauge theory, which also encompasses the Standard Model, with higher scalar representation(s) (J(i),X(i)J^{(i)},X^{(i)}). We show that the field profiles describing the sphaleron in higher scalar multiplet, have similar trends like the doublet case with respect to the radial distance. We compute the sphaleron energy and find that it scales linearly with the vacuum expectation value of the scalar field and its slope depends on the representation. We also investigate the effect of U(1)U(1) gauge field and find that it is small for the physical value of the mixing angle, θW\theta_{W} and resembles the case for the doublet. For higher representations, we show that the criterion for strong first order phase transition, vc/Tc>ηv_{c}/T_{c}>\eta, is relaxed with respect to the doublet case, i.e. η<1\eta<1.Comment: 20 pages, 5 figures & 1 table, published versio

    Insufficient sun exposure has become a real public health problem

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    This is the final version. Available on open access from MDPI via the DOI in this recordThis article aims to alert the medical community and public health authorities to accumulating evidence on health benefits from sun exposure, which suggests that insufficient sun exposure is a significant public health problem. Studies in the past decade indicate that insufficient sun exposure may be responsible for 340,000 deaths in the United States and 480,000 deaths in Europe per year, and an increased incidence of breast cancer, colorectal cancer, hypertension, cardiovascular disease, metabolic syndrome, multiple sclerosis, Alzheimer’s disease, autism, asthma, type 1 diabetes and myopia. Vitamin D has long been considered the principal mediator of beneficial effects of sun exposure. However, oral vitamin D supplementation has not been convincingly shown to prevent the above conditions; thus, serum 25(OH)D as an indicator of vitamin D status may be a proxy for and not a mediator of beneficial effects of sun exposure. New candidate mechanisms include the release of nitric oxide from the skin and direct effects of ultraviolet radiation (UVR) on peripheral blood cells. Collectively, this evidence indicates it would be wise for people living outside the tropics to ensure they expose their skin sufficiently to the sun. To minimize the harms of excessive sun exposure, great care must be taken to avoid sunburn, and sun exposure during high ambient UVR seasons should be obtained incrementally at not more than 5–30 min a day (depending on skin type and UV index), in season-appropriate clothing and with eyes closed or protected by sunglasses that filter UVR.Sunshine Health Foundation (SHF

    Implication of long-distance regulation of the HOXA cluster in a patient with postaxial polydactyly

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    Apparently balanced chromosomal inversions may lead to disruption of developmentally important genes at the breakpoints of the inversion, causing congenital malformations. Characterization of such inversions may therefore lead to new insights in human development. Here, we report on a de novo inversion of chromosome 7 (p15.2q36.3) in a patient with postaxial polysyndactyly. The breakpoints do not disrupt likely candidate genes for the limb phenotype observed in the patient. However, on the p-arm the breakpoint separates the HOXA cluster from a gene desert containing several conserved noncoding elements, suggesting that a disruption of a cis-regulatory circuit of the HOXA cluster could be the underlying cause of the phenotype in this patient

    Strong interferon-gamma mediated cellular immunity to scrub typhus demonstrated using a novel whole cell antigen ELISpot assay in rhesus macaques and humans

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    Scrub typhus is a febrile infection caused by the obligate intracellular bacterium Orientia tsutsugamushi, which causes significant morbidity and mortality across the Asia-Pacific region. The control of this vector-borne disease is challenging due to humans being dead-end hosts, vertical maintenance of the pathogen in the vector itself, and a potentially large rodent reservoir of unclear significance, coupled with a lack of accurate diagnostic tests. Development of an effective vaccine is highly desirable. This however requires better characterization of the natural immune response of this neglected but important disease. Here we implement a novel IFN-γ ELISpot assay as a tool for studying O. tsutsugamushi induced cellular immune responses in an experimental scrub typhus rhesus macaque model and human populations. Whole cell antigen for O. tsutsugamushi (OT-WCA) was prepared by heat inactivation of Karp-strain bacteria. Rhesus macaques were infected intradermally with O. tsutsugamushi. Freshly isolated peripheral blood mononuclear cells (PBMC) from infected (n = 10) and uninfected animals (n = 5) were stimulated with OT-WCA, and IFN-γ secreting cells quantitated by ELISpot assay at five time points over 28 days. PBMC were then assayed from people in a scrub typhus-endemic region of Thailand (n = 105) and responses compared to those from a partially exposed population in a non-endemic region (n = 14), and to a naïve UK population in UK (n = 12). Mean results at Day 0 prior to O. tsutsugamushi infection were 12 (95% CI 0-25) and 15 (2-27) spot-forming cells (SFC)/106 PBMC for infected and control macaques respectively. Strong O. tsutsugamushi-specific IFN-γ responses were seen post infection, with ELISpot responses 20-fold higher than baseline at Day 7 (mean 235, 95% CI 200-270 SFC/106 PBMC), 105-fold higher at Day 14 (mean 1261, 95% CI 1,097-1,425 SFC/106 PBMC), 125-fold higher at Day 21 (mean 1,498, 95% CI 1,496-1,500 SFC/106 PBMC) and 118-fold higher at Day 28 (mean 1,416, 95% CI 1,306-1,527 SFC/106 PBMC). No significant change was found in the control group at any time point compared to baseline. Humans from a scrub typhus endemic region of Thailand had mean responses of 189 (95% CI 88-290) SFC/106 PBMC compared to mean responses of 40 (95% CI 9-71) SFC/106 PBMC in people from a non-endemic region and 3 (95% CI 0-7) SFC/106 PBMC in naïve controls. In summary, this highly sensitive assay will enable field immunogenicity studies and further characterization of the host response to O. tsutsugamushi, and provides a link between human and animal models to accelerate vaccine development

    Design of agile supply chains including analysing the trade-off between number of partners and reliability

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    The reliability of supply partners is particularly vital in agile supply chains as it is vulnerable to the inability of a supply partner to meet its high responsiveness and flexibility requirements resulting in the disruption of the whole network. Disruption can have expensive and extensive results for the entire agile supply chain. To mitigate the risk of disruption and improve the reliability of the whole agile supply chain, decision-makers need to pay more attention to supply chain design and construction, whilst simultaneously taking into account the sourcing strategy decisions. This paper proposes a series of models for the design of agile supply chains using dynamic programming modelling. These provide decision-makers with a systematic way of analysing one of the key decisions of sourcing strategy, namely the trade-off between the number of supply partners and reliability. The efficacy of the models is demonstrated through their application to a Chinese bus and coach manufacturer by way of an empirical illustration. The results show that this approach is effective for this application and it can be applied in other related decision-making scenarios. The methods offered in this paper provide managers with a practical tool to design their agile supply chains while considering the trade-offs between the number of partners and the reliability of the entire agile supply chain

    New Insights into the Apoptotic Process in Mollusks: Characterization of Caspase Genes in Mytilus galloprovincialis

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    Apoptosis is an essential biological process in the development and maintenance of immune system homeostasis. Caspase proteins constitute the core of the apoptotic machinery and can be categorized as either initiators or effectors of apoptosis. Although the genes encoding caspase proteins have been described in vertebrates and in almost all invertebrate phyla, there are few reports describing the initiator and executioner caspases or the modulation of their expression by different stimuli in different apoptotic pathways in bivalves. In the present work, we characterized two initiator and four executioner caspases in the mussel Mytilus galloprovincialis. Both initiators and executioners showed structural features that make them different from other caspase proteins already described. Evaluation of the genes’ tissue expression patterns revealed extremely high expression levels within the gland and gills, where the apoptotic process is highly active due to the clearance of damaged cells. Hemocytes also showed high expression values, probably due to of the role of apoptosis in the defense against pathogens. To understand the mechanisms of caspase gene regulation, hemocytes were treated with UV-light, environmental pollutants and pathogen-associated molecular patterns (PAMPs) and apoptosis was evaluated by microscopy, flow cytometry and qPCR techniques. Our results suggest that the apoptotic process could be tightly regulated in bivalve mollusks by overexpression/suppression of caspase genes; additionally, there is evidence of caspase-specific responses to pathogens and pollutants. The apoptotic process in mollusks has a similar complexity to that of vertebrates, but presents unique features that may be related to recurrent exposure to environmental changes, pollutants and pathogens imposed by their sedentary nature

    Detection of Atherosclerotic Inflammation by 68^{68}Ga-DOTATATE PET Compared to [18^{18}F]FDG PET Imaging

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    Background\textbf{Background} Inflammation drives atherosclerotic plaque rupture. Although inflammation can be measured using fluorine-18-labeled fluorodeoxyglucose positron emission tomography ([18^{18}F]FDG PET), [18^{18}F]FDG lacks cell specificity, and coronary imaging is unreliable because of myocardial spillover. Objectives\textbf{Objectives} Objectives This study tested the efficacy of gallium-68-labeled DOTATATE (68^{68}Ga-DOTATATE), a somatostatin receptor subtype-2 (SST2)-binding PET tracer, for imaging atherosclerotic inflammation. Methods\textbf{Methods} We confirmed 68^{68}Ga-DOTATATE binding in macrophages and excised carotid plaques. 68^{68}Ga-DOTATATE PET imaging was compared to [18^{18}F]FDG PET imaging in 42 patients with atherosclerosis. Results\textbf{Results} Target SSTR2\textit{SSTR2} gene expression occurred exclusively in “proinflammatory” M1 macrophages, specific 68^{68}Ga-DOTATATE ligand binding to SST2_{2} receptors occurred in CD68-positive macrophage-rich carotid plaque regions, and carotid SSTR2\textit{SSTR2} mRNA was highly correlated with in vivo 68^{68}Ga-DOTATATE PET signals (r = 0.89; 95% confidence interval [CI]: 0.28 to 0.99; p = 0.02). 68^{68}Ga-DOTATATE mean of maximum tissue-to-blood ratios (mTBRmax_{max}) correctly identified culprit versus nonculprit arteries in patients with acute coronary syndrome (median difference: 0.69; interquartile range [IQR]: 0.22 to 1.15; p = 0.008) and transient ischemic attack/stroke (median difference: 0.13; IQR: 0.07 to 0.32; p = 0.003). 68^{68}Ga-DOTATATE mTBRmax_{max} predicted high-risk coronary computed tomography features (receiver operating characteristics area under the curve [ROC AUC]: 0.86; 95% CI: 0.80 to 0.92; p < 0.0001), and correlated with Framingham risk score (r = 0.53; 95% CI: 0.32 to 0.69; p <0.0001) and [18^{18}F]FDG uptake (r = 0.73; 95% CI: 0.64 to 0.81; p < 0.0001). [18^{18}F]FDG mTBRmax_{max} differentiated culprit from nonculprit carotid lesions (median difference: 0.12; IQR: 0.0 to 0.23; p = 0.008) and high-risk from lower-risk coronary arteries (ROC AUC: 0.76; 95% CI: 0.62 to 0.91; p = 0.002); however, myocardial [18^{18}F]FDG spillover rendered coronary [18^{18}F]FDG scans uninterpretable in 27 patients (64%). Coronary 68^{68}Ga-DOTATATE PET scans were readable in all patients. Conclusions\textbf{Conclusions} We validated 68^{68}Ga-DOTATATE PET as a novel marker of atherosclerotic inflammation and confirmed that 68^{68}Ga-DOTATATE offers superior coronary imaging, excellent macrophage specificity, and better power to discriminate high-risk versus low-risk coronary lesions than [18^{18}F]FDG. (Vascular Inflammation Imaging Using Somatostatin Receptor Positron Emission Tomography [VISION]; NCT02021188)This study was funded by the Wellcome Trust and supported by the National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre and the Cambridge Clinical Trials Unit. Dr. Tarkin is supported by a Wellcome Trust research training fellowship (104492/Z/14/Z). Dr. Evans is supported by a Dunhill Medical Trust fellowship (RTF44/0114). Dr. Chowdhury is supported by Royal College of Surgeons of England and British Heart Foundation (BHF) fellowships (FS/16/29/31957). Drs. Manavaki and Warburton are supported by the NIHR Biomedical Research Centres. Drs. Yu and Frontini are supported by the BHF (RE/13/6/30180). Dr. Fryer is supported by Higher Education Funding Council for England (HEFCE). Dr. Groves is supported by the University College London Hospital NIHR Biomedical Research Centre; and has received grant support from GlaxoSmithKline. Dr. Ouwehand’s laboratory is funded by EU-FP7 project Blueprint (Health-F5-2011-282510), BHF (PG-0310-1002 and RG/09/12/28096), and National Health Service Blood and Transplant. Dr. Bennett is supported by NIHR and BHF. Dr. Davenport is supported by research grants from Wellcome Trust (107715/Z/15/Z), Medical Research Council (MC_PC_14116), and BHF (RE-13-6-3180). Dr. Rudd is supported by the NIHR, BHF, Wellcome Trust, and HEFCE

    Effect of water availability pattern on yield of pearl millet in semi-arid tropical environments

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    Throughout much of the semi-arid tropics, fluctuations in grain yield can largely be attributed to differences in timing and intensity of drought stress. Since seasonal rainfall in these environments is often poorly related to grain yield, the aim of this paper was to establish a relationship between water availability and grain yield for pearl millet (Pennisetum glaucum (L.) R. Br.), grown across 24 semi-arid tropical environments in India. We used a simple soil water budget to calculate a water satisfaction index (WSI) throughout the season. The cumulative WSI at maturity explained 76% of the variance in grain yield. This was three times as much as explained by actual rainfall, because WSI accounted for differences in water losses and pan evaporation. A classification of environments into four groups of water availability patterns explained 75% of the environmental sum of squares for grain yield. For a subset of 13 environments, environmental differences in grain number could also be explained by water availability patterns, whereas differences in grain mass were related to both water availability and temperature. Our results indicate that cumulative WSI, which is an integrated measure of plant-available water, can provide an adequate estimation of the environmental potential for yield in environments where grain yield is mainly limited by variable availability of water
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