294 research outputs found

    Influence of life-style choices on locomotor disability, arthritis and cardiovascular disease in older women: prospective cohort study.

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    BACKGROUND: many chronic conditions have their roots in modifiable health-related behaviours. METHODS: a total of 4,286 women aged 60-79 in the British Women's Heart and Health Study are followed up for incident cardiovascular disease (CVD), arthritis and locomotor disability over 7 years. Self-reported smoking, alcohol consumption, exercise and fruit intake at baseline is also available. Associations between these and each outcome, plus a composite outcome, are investigated in those without prevalent disease at baseline using logistic regression with multiple imputation. RESULTS: ex-smokers and current smokers showed increased odds of locomotor disability, CVD and the combined outcome. Less regular exercisers had increased odds of all outcomes, particularly locomotor disability. There was no evidence that alcohol or fruit intake was associated with any outcome. Population attributable fractions (PAFs) suggest in addition to the influence of smoking and alcohol, exercise accounts for 9% of incident locomotor disability, 5% of CVD and 4% of arthritis. All four lifestyle factors combined account for 17% of incident locomotor disability and 9% of incident conditions combined. CONCLUSIONS: never smokers and regular exercisers had substantially reduced odds of 7-year disability onset. Low PAFs suggest changes in health-related behaviours in older women would result in only modest reductions in common chronic conditions

    Compliance-adjusted intervention effects in survival data

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    Time-to-event endpoints are a common outcome of interest in randomised clinical trials. The primary analysis should usually be by intention-to-treat, giving an indication of the effectiveness of the intervention in a population as a whole. However, the benefit specifically for an individual receiving the intervention is becoming increasingly important as patient decisions become more evidence-based. Effectiveness is defined as the benefit of intervention as actually applied, and may be estimated from simple all-or-nothing compliance data. Efficacy, on the other hand, is the benefit of intervention under ideal circumstances, and requires more complex compliance data. Intervention effectiveness and efficacy after accounting for non-compliance can be estimated in various ways, some of which have already been implemented in Stata (e.g. Author-Email: strbee). Recently, Loeys and Goetghebeur (2003) provided new methodology using proportional-hazards techniques in survival data where compliance is all-or-nothing in the intervention arm and perfect in the control arm. Here, their method is implemented in Stata. The output is a hazard ratio for the effectiveness of intervention, adjusted for observed adherence to intervention in the treated group. An example application is discussed for a subset of a large, randomised trial of screening where the average benefit of 26% risk reduction becomes a 34% risk reduction for individuals attending screening.

    Purification and Biochemical Characterization of the DNA Binding Domain of the Nitrogenase Transcriptional Activator NifA from \u3cem\u3eGluconacetobacter diazotrophicus\u3c/em\u3e

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    NifA is a σ54 activator that turns on bacterial nitrogen fixation under reducing conditions and when fixed cellular nitrogen levels are low. The redox sensing mechanism in NifA is poorly understood. In α- and β-proteobacteria, redox sensing involves two pairs of Cys residues within and immediately following the protein’s central AAA+ domain. In this work, we examine if an additional Cys pair that is part of a C(X)5 C motif and located immediately upstream of the DNA binding domain of NifA from the α-proteobacterium Gluconacetobacter diazotrophicus (Gd) is involved in redox sensing. We hypothesize that the Cys residues’ redox state may directly influence the DNA binding domain’s DNA binding affinity and/or alter the protein’s oligomeric sate. Two DNA binding domain constructs were generated, a longer construct (2C-DBD), consisting of the DNA binding domain with the upstream Cys pair, and a shorter construct (NC-DBD) that lacks the Cys pair. The Kd of NC-DBD for its cognate DNA sequence (nifH-UAS) is equal to 20.0 µM. The Kd of 2C-DBD for nifH-UAS when the Cys pair is oxidized is 34.5 µM. Reduction of the disulfide bond does not change the DNA binding affinity. Additional experiments indicate that the redox state of the Cys residues does not influence the secondary structure or oligomerization state of the NifA DNA binding domain. Together, these results demonstrate that the Cys pair upstream of the DNA binding domain of Gd-NifA does not regulate DNA binding or domain dimerization in a redox dependent manner

    Modelling the impact of changes to abdominal aortic aneurysm screening and treatment services in England during the COVID-19 pandemic.

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    BackgroundThe National Health Service (NHS) abdominal aortic aneurysm (AAA) screening programme (NAAASP) in England screens 65-year-old men. The programme monitors those with an aneurysm, and early intervention for large aneurysms reduces ruptures and AAA-related mortality. AAA screening services have been disrupted following COVID-19 but it is not known how this may impact AAA-related mortality, or where efforts should be focussed as services resume.MethodsWe repurposed a previously validated discrete event simulation model to investigate the impact of COVID-19-related service disruption on key outcomes. This model was used to explore the impact of delayed invitation and reduced attendance in men invited to screening. Additionally, we investigated the impact of temporarily suspending scans, increasing the threshold for elective surgery to 7cm and increasing drop-out in the AAA cohort under surveillance, using data from NAAASP to inform the population.FindingsDelaying invitation to primary screening up to two years had little impact on key outcomes whereas a 10% reduction in attendance could lead to a 2% lifetime increase in AAA-related deaths. In surveillance patients, a 1-year suspension of surveillance or increase in the elective threshold resulted in a 0.4% increase in excess AAA-related deaths (8% in those 5-5.4cm at the start). Longer suspensions or a doubling of drop-out from surveillance would have a pronounced impact on outcomes.InterpretationEfforts should be directed towards encouraging men to attend AAA screening service appointments post-COVID-19. Those with AAAs on surveillance should be prioritised as the screening programme resumes, as changes to these services beyond one year are likely to have a larger impact on surgical burden and AAA-related mortality

    Optimizing Surveillance and Re-intervention Strategy Following Elective Endovascular Repair of Abdominal Aortic Aneurysms

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    Background: EVAR for abdominal aortic aneurysm has an initial survival advantage over OR, but more frequent complications increase costs and long-term aneurysm-related mortality. Randomized controlled trials of EVAR versus OR have shown EVAR is not cost-effective over a patient's lifetime. However, in the EVAR-1 trial, postoperative surveillance may have been sub-optimal, as the importance of sac growth as a predictor of graft failure was overlooked. Methods: Real-world data informed a discrete event simulation model of postoperative outcomes following EVAR. Outcomes observed EVAR-1 were compared with those from 5 alternative postoperative surveillance and reintervention strategies. Key events, quality-adjusted life years and costs were predicted. The impact of using complication and rupture rates from more recent devices, imaging and re-intervention methods was also explored. Results: Compared with observed EVAR-1 outcomes, modeling full adherence to the EVAR-1 scan protocol reduced abdominal aortic aneurysm (AAA) deaths by 3% and increased elective re-interventions by 44%. European Society re-intervention guidelines provided the most clinically effective strategy, with an 8% reduction in AAA deaths, but a 52% increase in elective re-interventions. The cheapest and most cost-effective strategy used lifetime annual ultrasound in primary care with confirmatory computed tomography if necessary, and reduced AAA-related deaths by 5%. Using contemporary rates for complications and rupture did not alter these conclusions. Conclusions: All alternative strategies improved clinical benefits compared with the EVAR-1 trial. Further work is needed regarding the cost and accuracy of primary care ultrasound, and the potential impact of these strategies in the comparison with OR.Peer reviewe

    Impairments of auditory scene analysis in Alzheimer's disease

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    Parsing of sound sources in the auditory environment or ‘auditory scene analysis’ is a computationally demanding cognitive operation that is likely to be vulnerable to the neurodegenerative process in Alzheimer’s disease. However, little information is available concerning auditory scene analysis in Alzheimer's disease. Here we undertook a detailed neuropsychological and neuroanatomical characterization of auditory scene analysis in a cohort of 21 patients with clinically typical Alzheimer's disease versus age-matched healthy control subjects. We designed a novel auditory dual stream paradigm based on synthetic sound sequences to assess two key generic operations in auditory scene analysis (object segregation and grouping) in relation to simpler auditory perceptual, task and general neuropsychological factors. In order to assess neuroanatomical associations of performance on auditory scene analysis tasks, structural brain magnetic resonance imaging data from the patient cohort were analysed using voxel-based morphometry. Compared with healthy controls, patients with Alzheimer's disease had impairments of auditory scene analysis, and segregation and grouping operations were comparably affected. Auditory scene analysis impairments in Alzheimer's disease were not wholly attributable to simple auditory perceptual or task factors; however, the between-group difference relative to healthy controls was attenuated after accounting for non-verbal (visuospatial) working memory capacity. These findings demonstrate that clinically typical Alzheimer's disease is associated with a generic deficit of auditory scene analysis. Neuroanatomical associations of auditory scene analysis performance were identified in posterior cortical areas including the posterior superior temporal lobes and posterior cingulate. This work suggests a basis for understanding a class of clinical symptoms in Alzheimer's disease and for delineating cognitive mechanisms that mediate auditory scene analysis both in health and in neurodegenerative disease

    Self-Monitoring and Management of Blood Pressure in Patients with Stroke or TIA: An Economic Evaluation of TEST-BP, A Randomised Controlled Trial

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    Abstract: Background: Prevention of secondary stroke following initial ictus is an important focus of after-stroke care. Blood pressure (BP) is a key risk factor, so usual care following stroke or transient ischaemic attack includes regular BP checks and monitoring of anti-hypertensive medication. This is traditionally carried out in primary care, but the evidence supporting self-monitoring and self-guided management of BP in the general population with hypertension is growing. Objective: Our objective was to estimate the cost effectiveness of treatment as usual (TAU) versus (1) self-monitoring of BP (S-MON) and (2) self-monitoring and guided self-management of anti-hypertensive medication (S-MAN). Methods: This was a within-trial economic evaluation of a randomised controlled trial estimating the incremental cost per 1 mmHg BP reduction and per quality-adjusted life-year (QALY) gained over a 6-month time horizon from the perspective of the UK National Health Service (NHS). Results: Data were evaluable for 140 participants. Costs per patient were £473, £853 and £1035; mean reduction in systolic BP (SBP) was 3.6, 6.7 and 6.1 mmHg, and QALYs accrued were 0.427, 0.422 and 0.423 for TAU, S-MON and S-MAN, respectively. No statistically significant differences in incremental costs or outcomes were detected. On average, S-MAN was dominated or extended dominated. The incremental cost per 1 mmHg BP reduction from S-MON versus TAU was £137. Conclusion: On average, S-MAN is an inefficient intervention. S-MON may be cost effective, depending on the willingness to pay for a 1 mmHg BP reduction, although it yielded fewer QALYs over the within-trial time horizon. Decision modelling is required to explore the longer-term costs and outcomes

    Comparative Analysis of the Frequency and Distribution of Stem and Progenitor Cells in the Adult Mouse Brain

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    cells (NSCs) and progenitor cells, but it cannot discriminate between these two populations. Given two assays have purported to overcome this shortfall, we performed a comparative analysis of the distribution and frequency of NSCs and progenitor cells detected in 400 m coronal segments along the ventricular neuraxis of the adult mouse brain using the neurosphere assay, the neural colony forming cell assay (N-CFCA), and label-retaining cell (LRC) approach. We observed a large variation in the number of progenitor/stem cells detected in serial sections along the neuraxis, with the number of neurosphereforming cells detected in individual 400 m sections varying from a minimum of eight to a maximum of 891 depending upon the rostral-caudal coordinate assayed. Moreover, the greatest variability occurred in the rostral portion of the lateral ventricles, thereby explaining the large variation in neurosphere frequency previously reported. Whereas the overall number of neurospheres (3730 276) or colonies (4275 124) we detected along the neuraxis did not differ significantly, LRC numbers were significantly reduced (1186 188, 7 month chase) in comparison to both total colonies and neurospheres. Moreover, approximately two orders of magnitude fewer NSC-derived colonies (50 10) were detected using the N-CFCA as compared to LRCs. Given only 5% of the LRCs are cycling (BrdU/Ki-67) or competent to divide (BrdU/Mcm-2), and proliferate upon transfer to culture, it is unclear whether this technique selectively detects endogenous NSCs. Overall, caution should be taken with the interpretation and employment of all these techniques

    How do primary care doctors in England and Wales code and manage people with chronic kidney disease? Results from the National Chronic Kidney Disease Audit.

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    BACKGROUND: In the UK, primary care records are electronic and require doctors to ascribe disease codes to direct care plans and facilitate safe prescribing. We investigated factors associated with coding of chronic kidney disease (CKD) in patients with reduced kidney function and the impact this has on patient management. METHODS: We identified patients meeting biochemical criteria for CKD (two estimated glomerular filtration rates 90 days apart) from 1039 general practitioner (GP) practices in a UK audit. Clustered logistic regression was used to identify factors associated with coding for CKD and improvement in coding as a result of the audit process. We investigated the relationship between coding and five interventions recommended for CKD: achieving blood pressure targets, proteinuria testing, statin prescription and flu and pneumococcal vaccination. RESULTS: Of 256 000 patients with biochemical CKD, 30% did not have a GP CKD code. Males, older patients, those with more severe CKD, diabetes or hypertension or those prescribed statins were more likely to have a CKD code. Among those with continued biochemical CKD following audit, these same characteristics increased the odds of improved coding. Patients without any kidney diagnosis were less likely to receive optimal care than those coded for CKD [e.g. odds ratio for meeting blood pressure target 0.78 (95% confidence interval 0.76-0.79)]. CONCLUSION: Older age, male sex, diabetes and hypertension are associated with coding for those with biochemical CKD. CKD coding is associated with receiving key primary care interventions recommended for CKD. Increased efforts to incentivize CKD coding may improve outcomes for CKD patients
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