421 research outputs found
The effect of single nucleotide polymorphisms of oxidative stress genes and low grade inflammation upon pulse wave contour analysis, a useful non invasive, intermediate vascular phenotype.
Cardiovascular disease remains a major cause of mortality and morbidity and is underpinned by Oxidative stress, within which, inactivation of nitric oxide (NO) by superoxide (SO) and other reactive oxygen species is characteristic. Two major enzyme systems are implicated within oxidative stress; NAD(P)H oxidase and endothelial nitric oxide synthase (eNOS). eNOS generates NO while at the same time, and within the same cells, NAD(P)H plays a powerful role in the generation of SO. Evidence is accumulating that polymorphisms of the genes encoding these enzyme systems may play an important role in the pathophysiology of CAD. Additionally there has been much recent interest in both biochemical markers of oxidative stress and low grade chronic inflammation as well as a non invasive vascular phenotype, pulse wave analysis. This thesis reports a series of studies (utilising the techniques described in chapter 2) which aimed to ascertain:-
The reproducibility of pulse contour analysis as a non invasive intermediate cardiovascular phenotype (Chapter 3).
Whether common single nucleotide polymorphisms of the p22phox gene CYBA and
the endothelial nitric oxide synthase gene, NOS3, have an effect upon arterial compliance in patients with coronary artery disease (Chapters 4,5 and 6).
In healthy volunteers, free of cardiovascular disease whether a relationship existed between markers of low grade inflammation and arterial stiffness (Chapter 7).
Chapter 3: The reproducibility of diastolic pulse wave contour analysis and its relation to systolic pulse contour analysis.
This clinical study demonstrated that both large (C1) and small artery (C2) compliance values were reproducible and that there was a significant correlation between both Augmentation Index (AIx) and C1and AIx and C2 in healthy volunteers and though there was no association
between AIx and C1 in patients with coronary artery disease AIx did correlate with C2 in this population.
Chapter 4: The effect of the G894T SNP of the NOS3 gene upon arterial stiffness in patients with coronary artery disease.
There was no association observed between this polymorphism and blood pressure or large artery compliance however ANOVA revealed a statistically significant association for TT homozygosity and small artery compliance. The highest small artery compliance was seen in the patients homozygous for the G allele, an intermediate value observed in heterozygotes and the lowest value demonstrated in patients homozygous for the T allele. Multiple regression analysis, examining the possible contribution of confounders showed that only small artery compliance was significant when NOS3 G894T genotype was assigned as the dependent variable.
Chapter 5: The C242T single nucleotide polymorphism of the CYBA gene and blood pressure and arterial compliance in patients with coronary artery disease.
We sought to examine the influence of the C242T SNP of CYBA upon vascular compliance and blood pressure using the dominant allele model. The presence of the 242T allele was associated with significantly higher systolic blood pressure. Patients homozygous for the C allele had lower systolic blood pressure than heterozygotes and patients homozygous for the T allele. There was no statistically significant effect upon diastolic blood pressure but there was however a significant association observed between the 242T allele and pulse pressure.
Chapter 6: Combined analysis of NOS3 G894T and CYBA C242T genotypes upon arterial stiffness.
In order to contrast the arterial stiffness between the favourable versus the non-favourable genotypes patients homozygous for the NOS3 G allele and homozygous for the CYBA C allele were compared with those homozygous for the NOS3T allele and possessing the CYBA 242T allele. The former displayed higher large and small artery compliance than the latter group. Multiple regression analysis, examining the possible contribution of confounders showed that only the large and small artery compliance values contributed significantly when genotype was assigned as the dependent variable.
Chapter 7 Chronic low grade inflammation and insulin resistance and arterial compliance in healthy volunteers.
Within healthy volunteers multiple regression analysis showed that small artery compliance was significantly associated with IL 6, CRP and ICAM. Augmentation index showed only an association with ICAM1. There was no significant correlation between Adiponectin levels and either of the arterial stiffness parameters studied.
Conclusions
Diastolic pulse wave contour analysis is a reproducible assessment of arterial stiffness with the potential to represent a high fidelity non invasive vascular phenotype.
Small artery compliance is correlated with Augmentation Index and although the measurements are not analogous they both represent useful means of acquiring quantitative data concerning arterial stiffness.
The 242T allele of the p22phox gene, CYBA, is associated with decreased large but not small artery compliance and increased systolic and pulse pressure.
Homozygosity for a common NOS3 polymorphism (894 GT) was associated with decreased small artery compliance but not with large artery compliance or blood pressure.
The markers of chronic inflammation Interleukin 6, ICAM and hsCRP but not Adiponectin, a marker of Insulin resistance, predict small artery compliance in healthy individuals apparently free of vascular disease
International Lessons in New Methods for Grading and Integrating Cost Effectiveness Evidence into Clinical Practice Guidelines
Economic evidence is influential in health technology assessment world-wide. Clinical Practice Guidelines (CPG) can enable economists to include economic information on health care provision. Application of economic evidence in CPGs, and its integration into clinical practice and national decision making is hampered by objections from professions, paucity of economic evidence or lack of policy commitment. The use of state-of-art economic methodologies will improve this. Economic evidence can be graded by 'checklists' to establish the best evidence for decision making given methodological rigor. New economic evaluation checklists, Multi-Criteria Decision Analyses (MCDA) and other decision criteria enable health economists to impact on decision making world-wide. We analyse the methodologies for integrating economic evidence into CPG agencies globally, including the Agency of Health Research and Quality (AHRQ) in the USA, National Health and Medical Research Council (NHMRC) and Australian political reforms. The Guidelines and Economists Network International (GENI) Board members from Australia, UK, Canada and Denmark presented the findings at the conference of the International Health Economists Association (IHEA) and we report conclusions and developments since. The Consolidated Guidelines for the Reporting of Economic Evaluations (CHEERS) 24 item check list can be used by AHRQ, NHMRC, other CPG and health organisations, in conjunction with the Drummond ten-point check list and a questionnaire that scores that checklist for grading studies, when assessing economic evidence. Cost-effectiveness Analysis (CEA) thresholds, opportunity cost and willingness-to-pay (WTP) are crucial issues for decision rules in CEA generally, including end-of-life therapies. Limitations of inter-rater reliability in checklists can be addressed by including more than one assessor to reach a consensus, especially when impacting on treatment decisions. We identify priority areas to generate economic evidence for CPGs by NHMRC, AHRQ, and other agencies. The evidence may cover demand for care issues such as involved time, logistics, innovation price, price sensitivity, substitutes and complements, WTP, absenteeism and presentism. Supply issues may include economies of scale, efficiency changes, and return on investment. Involved equity and efficiency measures may include cost-of-illness, disease burden, quality-of-life, budget impact, cost-effective ratios, net benefits and disparities in access and outcomes.. Priority setting remains essential and trade-off decisions between policy criteria can be based on MCDA, both in evidence based clinical medicine and in health planning
Economic evaluation alongside pragmatic randomised trials: developing a standard operating procedure for clinical trials units
<p>Abstract</p> <p>Background</p> <p>There is wide recognition that pragmatic randomised trials are the best vehicle for economic evaluation. This is because trials provide the best chance of ensuring internal validity, not least through the rigorous prospective collection of patient-specific data. Furthermore the marginal cost of collecting economic data alongside clinical data is typically modest. UK Clinical Research Collaboration (UKCRC) does not require a standard operating procedure (SOP) for economic evaluation as a prerequisite for trial unit registration. We judge that such a SOP facilitates the integration of health economics into trials.</p> <p>Methods</p> <p>A collaboration between health economists and trialists at Bangor University led to the development of a SOP for economic evaluation alongside pragmatic trials, in addition to the twenty SOPs required by UKCRC for registration, which include randomisation, data management and statistical analysis.</p> <p>Results</p> <p>Our recent telephone survey suggests that no other UKCRC-registered trials unit currently has an economic SOP.</p> <p>Conclusion</p> <p>We argue that UKCRC should require, from all Trials Units undertaking economic evaluation and seeking registration or re-registration, a SOP for economic evaluation as one of their portfolio of supporting SOPs.</p
In vivo analysis of proteomes and interactomes using Parallel Affinity Capture (iPAC) coupled to mass spectrometry.
Affinity purification coupled to mass spectrometry provides a reliable method for identifying proteins and their binding partners. In this study we have used Drosophila melanogaster proteins triple tagged with Flag, Strep II, and Yellow fluorescent protein in vivo within affinity pull-down experiments and isolated these proteins in their native complexes from embryos. We describe a pipeline for determining interactomes by Parallel Affinity Capture (iPAC) and show its use by identifying partners of several protein baits with a range of sizes and subcellular locations. This purification protocol employs the different tags in parallel and involves detailed comparison of resulting mass spectrometry data sets, ensuring the interaction lists achieved are of high confidence. We show that this approach identifies known interactors of bait proteins as well as novel interaction partners by comparing data achieved with published interaction data sets. The high confidence in vivo protein data sets presented here add new data to the currently incomplete D. melanogaster interactome. Additionally we report contaminant proteins that are persistent with affinity purifications irrespective of the tagged bait.This project is funded by the Welcome Trust.This is the final version of the article. It was first available from ASBMB via http://dx.doi.org/10.1074/mcp.M110.00238
Linked randomised controlled trials of face-to-face and electronic brief intervention methods to prevent alcohol related harm in young people aged 14–17 years presenting to Emergency Departments (SIPS junior)
Background: Alcohol is a major global threat to public health. Although the main burden of chronic alcohol-related disease is in adults, its foundations often lie in adolescence. Alcohol consumption and related harm increase steeply from the age of 12 until 20 years. Several trials focusing upon young people have reported significant positive effects of brief interventions on a range of alcohol consumption outcomes. A recent review of reviews also suggests that electronic brief interventions (eBIs) using internet and smartphone technologies may markedly reduce alcohol consumption compared with minimal or no intervention controls.
Interventions that target non-drinking youth are known to delay the onset of drinking behaviours. Web based alcohol interventions for adolescents also demonstrate significantly greater reductions in consumption and harm among ‘high-risk’ drinkers; however changes in risk status at follow-up for non-drinkers or low-risk
drinkers have not been assessed in controlled trials of brief alcohol interventions
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Clinical Significance of Bronchodilator Responsiveness Evaluated by Forced Vital Capacity in COPD: SPIROMICS Cohort Analysis.
ObjectiveBronchodilator responsiveness (BDR) is prevalent in COPD, but its clinical implications remain unclear. We explored the significance of BDR, defined by post-bronchodilator change in FEV1 (BDRFEV1) as a measure reflecting the change in flow and in FVC (BDRFVC) reflecting the change in volume.MethodsWe analyzed 2974 participants from a multicenter observational study designed to identify varying COPD phenotypes (SPIROMICS). We evaluated the association of BDR with baseline clinical characteristics, rate of prospective exacerbations and mortality using negative binomial regression and Cox proportional hazards models.ResultsA majority of COPD participants exhibited BDR (52.7%). BDRFEV1 occurred more often in earlier stages of COPD, while BDRFVC occurred more frequently in more advanced disease. When defined by increases in either FEV1 or FVC, BDR was associated with a self-reported history of asthma, but not with blood eosinophil counts. BDRFVC was more prevalent in subjects with greater emphysema and small airway disease on CT. In a univariate analysis, BDRFVC was associated with increased exacerbations and mortality, although no significance was found in a model adjusted for post-bronchodilator FEV1.ConclusionWith advanced airflow obstruction in COPD, BDRFVC is more prevalent in comparison to BDRFEV1 and correlates with the extent of emphysema and degree of small airway disease. Since these associations appear to be related to the impairment of FEV1, BDRFVC itself does not define a distinct phenotype nor can it be more predictive of outcomes, but it can offer additional insights into the pathophysiologic mechanism in advanced COPD.Clinical trials registrationClinicalTrials.gov: NCT01969344T4
Analysis of the expression patterns, subcellular localisations and interaction partners of Drosophila proteins using a pigP protein trap library.
Although we now have a wealth of information on the transcription patterns of all the genes in the Drosophila genome, much less is known about the properties of the encoded proteins. To provide information on the expression patterns and subcellular localisations of many proteins in parallel, we have performed a large-scale protein trap screen using a hybrid piggyBac vector carrying an artificial exon encoding yellow fluorescent protein (YFP) and protein affinity tags. From screening 41 million embryos, we recovered 616 verified independent YFP-positive lines representing protein traps in 374 genes, two-thirds of which had not been tagged in previous P element protein trap screens. Over 20 different research groups then characterized the expression patterns of the tagged proteins in a variety of tissues and at several developmental stages. In parallel, we purified many of the tagged proteins from embryos using the affinity tags and identified co-purifying proteins by mass spectrometry. The fly stocks are publicly available through the Kyoto Drosophila Genetics Resource Center. All our data are available via an open access database (Flannotator), which provides comprehensive information on the expression patterns, subcellular localisations and in vivo interaction partners of the trapped proteins. Our resource substantially increases the number of available protein traps in Drosophila and identifies new markers for cellular organelles and structures.This work was supported by a project grant from the Wellcome Trust [076739], by a Wellcome Trust Principal Research Fellowship to D.StJ. [049818 and 080007], and by core support from the Wellcome Trust [092096] and Cancer Research UK [A14492].This is the final version of the article. It was first available from The Company of Biologists via http://dx.doi.org/10.1242/dev.11105
Bayesian Phylogeography Finds Its Roots
As a key factor in endemic and epidemic dynamics, the geographical distribution of viruses has been frequently interpreted in the light of their genetic histories. Unfortunately, inference of historical dispersal or migration patterns of viruses has mainly been restricted to model-free heuristic approaches that provide little insight into the temporal setting of the spatial dynamics. The introduction of probabilistic models of evolution, however, offers unique opportunities to engage in this statistical endeavor. Here we introduce a Bayesian framework for inference, visualization and hypothesis testing of phylogeographic history. By implementing character mapping in a Bayesian software that samples time-scaled phylogenies, we enable the reconstruction of timed viral dispersal patterns while accommodating phylogenetic uncertainty. Standard Markov model inference is extended with a stochastic search variable selection procedure that identifies the parsimonious descriptions of the diffusion process. In addition, we propose priors that can incorporate geographical sampling distributions or characterize alternative hypotheses about the spatial dynamics. To visualize the spatial and temporal information, we summarize inferences using virtual globe software. We describe how Bayesian phylogeography compares with previous parsimony analysis in the investigation of the influenza A H5N1 origin and H5N1 epidemiological linkage among sampling localities. Analysis of rabies in West African dog populations reveals how virus diffusion may enable endemic maintenance through continuous epidemic cycles. From these analyses, we conclude that our phylogeographic framework will make an important asset in molecular epidemiology that can be easily generalized to infer biogeogeography from genetic data for many organisms
1998 CSREES Wild Blueberry Project Results
The 1998 edition of the CSREES Wild Blueberry Project Results was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Separation of Maggot Infested Blueberries in the IQF Processing Line
2. Assessment of Preharvest Treatments on Wild blueberry Fruit Quality
3. Blueberries as a Natural Colorant for Breakfast Cereals
4. Factors Affecting Quality of IQF Wild Blueberries
5. Control Tactics for Wild blueberry Pest Insects
6. Biology and Ecology of Wild blueberry Pest Insects
7. Sustainable Pollination of Wild blueberry
8. Evaluation of Foliar Fungicides for Control of Mummy Berry
9. Phosphorus/Nitrogen Fertilizer Ratio
10. Effect of Boron Application Methods on Boron Uptake in Wild Blueberries
11. Effect of Zinc Application on Growth and Yield of Wild Blueberries
12. Effect of Soil pH of Nutrient Uptake
13. Crop Year Fertilization of Wild blueberry
14. Effect of Fertilizer Timing on Wild blueberry Growth and Productivity
15. Alternative Methods of Grass Control
16. Cultural Weed Management Using pH
17. Investigation of Hexazinone Alternatives for Weed Control
18. Evaluation of Hexazinone Applications in the Cropping Year
19. Effect of Surfactant and Ammonium Sulfate on Glyphosate Activity
20. Evaluation of Pronone MG® Spot Treatments for Control of St Jobnswort, Dogbane, Bracken Fem, Witch Grass/Fall Panicum and Bunchberry
21. Hexazinone Groundwater Surve
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