311 research outputs found
Inter-Strain Epigenomic Profiling Reveals a Candidate IAP Master Copy in C3H Mice.
Insertions of endogenous retroviruses cause a significant fraction of mutations in inbred mice but not all strains are equally susceptible. Notably, most new Intracisternal A particle (IAP) ERV mutagenic insertions have occurred in C3H mice. We show here that strain-specific insertional polymorphic IAPs accumulate faster in C3H/HeJ mice, relative to other sequenced strains, and that IAP transcript levels are higher in C3H/HeJ embryonic stem (ES) cells compared to other ES cells. To investigate the mechanism for high IAP activity in C3H mice, we identified 61 IAP copies in C3H/HeJ ES cells enriched with H3K4me3 (a mark of active promoters) and, among those tested, all are unmethylated in C3H/HeJ ES cells. Notably, 13 of the 61 are specific to C3H/HeJ and are members of the non-autonomous 1Δ1 IAP subfamily that is responsible for nearly all new insertions in C3H. One copy is full length with intact open reading frames and hence potentially capable of providing proteins i
L'impact de la CAO/FAO sur la QVT: le cas de Marconi
Suite à l'implantation de la CAO/F AO dans la compagnie Marconi Canada, une mesure de l'impact du changement sur la qualité de vie au travail (QVT) a été réalisée auprès de 104 utilisateurs de la nouvelle technologie. La QVT dans cette étude est perçue dans son sens le plus large englobant les dimensions du travail en soi, des conditions de travail, de la santé et la sécurité au travail et du contexte organisationnel. L'approche retenue pour mesurer les impacts est subjectiviste et ceux-ci sont différenciés, s'il y a lieu, selon la catégorie occupationnelle, le taux d'utilisation de la nouvelle technologie et la formation reçue en CAO/FAO.After the implementation of a CAD/CAM system at Marconi Canada, the impact of this new technology on the quality of worklife (QWL) of 104 users was assessed. In this study, QWL was defîned to encompass the characteristics of the work itself, working conditions, health and safety, and the organizational context. Respondents were asked how the new technology had affected the quality of their work life; information was also gathered on occupation, rate of utilisation of CAD/CAM procedures, and training received on the new technology.The results showed that enriching job content, improving interpersonal relations, and enhancing participation, cooperation, and communication all contributed to improving QWL. In contrast, increased mental burden, noise, isolation, control problems, aspects of the physical move, and health issues contributed to decreases in QWL. A further analysis, using concepts based on job satisfaction, showed that the respondents accorded the most importance to changes intrinsic to their work, most notably job enrichment
Which circulating antioxidant vitamins are confounded by socioeconomic deprivation? The MIDSPAN family study
<p><b>Background:</b> Antioxidant vitamins are often described as having “independent” associations with risk of cancer, cardiovascular disease (CVD) and mortality. We aimed to compare to what extent a range of antioxidant vitamins and carotenoids are associated with adulthood and childhood markers of socioeconomic deprivation and to adverse lifestyle factors.</p>
<p><b>Methods and Findings:</b> Socioeconomic and lifestyle measures were available in 1040 men and 1298 women from the MIDSPAN Family Study (30–59 years at baseline) together with circulating levels of vitamins A, C, E, and carotenoids (α-carotene, β-carotene, lutein and lycopene). Markers of socioeconomic deprivation in adulthood were consistently as strongly associated with lower vitamin C and carotenoid levels as markers of adverse lifestyle; the inverse association with overcrowding was particularly consistent (vitamin C and carotenoids range from 19.1% [95% CI 30.3–6.0] to 38.8% [49.9–25.3] lower among those in overcrowded residencies). These associations were consistent after adjusting for month, classical CVD risk factors, body mass index, physical activity, vitamin supplements, dietary fat and fibre intake. Similar, but weaker, associations were seen for childhood markers of deprivation. The association of vitamin A or E were strikingly different; several adult adverse lifestyle factors associated with higher levels of vitamin A and E, including high alcohol intake for vitamin A (9.5% [5.7–13.5]) and waist hip ratio for vitamin E (9.5% [4.8–14.4]), with the latter associations partially explained by classical risk factors, particularly cholesterol levels.</p>
<p><b>Conclusions:</b> Plasma vitamin C and carotenoids have strong inverse associations with adulthood markers of social deprivation, whereas vitamin A and E appear positively related to specific adverse lifestyle factors. These findings should help researchers better contextualize blood antioxidant vitamin levels by illustrating the potential limitations associated with making causal inferences without consideration of social deprivation.</p>
Vitamin D and subsequent all-age and premature mortality: a systematic review
<br>Background:
All-cause mortality in the population < 65 years is 30% higher in Glasgow than in equally deprived Liverpool and Manchester. We investigated a hypothesis that low vitamin D in this population may be associated with premature mortality via a systematic review and meta-analysis.</br>
<br>Methods:
Medline, EMBASE, Web of Science, the Cochrane Library and grey literature sources were searched until February 2012 for relevant studies. Summary statistics were combined in an age-stratified meta-analysis.</br>
<br>Results:
Nine studies were included in the meta-analysis, representing 24,297 participants, 5,324 of whom died during follow-up. The pooled hazard ratio for low compared to high vitamin D demonstrated a significant inverse association (HR 1.19, 95% CI 1.12-1.27) between vitamin D levels and all-cause mortality after adjustment for available confounders. In an age-stratified meta-analysis, the hazard ratio for older participants was 1.25 (95% CI 1.14-1.36) and for younger participants 1.12 (95% CI 1.01-1.24).</br>
<br>Conclusions:
Low vitamin D status is inversely associated with all-cause mortality but the risk is higher amongst older individuals and the relationship is prone to residual confounding. Further studies investigating the association between vitamin D deficiency and all-cause mortality in younger adults with adjustment for all important confounders (or using randomised trials of supplementation) are required to clarify this relationship.</br>
Effect of Left Atrial Function Index on Late Atrial Fibrillation Recurrence after Pulmonary Vein Isolation
Background: Although the rates of catheter ablation (CA) for atrial fibrillation (AF) are rapidly increasing, there are few predictors of outcome to help inform appropriate patient selection for this procedure. Traditional echocardiographic measures of atrial structure do not significantly reclassify risk of AF recurrence over and above the clinical risk factors. Left Atrial Function Index (LAFI) is a rhythm-independent measure of atrial function. We hypothesized that baseline LAFI would relate to AF recurrence after CA.
Methods: Pre-procedural echocardiograms from 170 participants, who underwent CA for AF and were enrolled in the UMMC AF Treatment Registry, were analyzed. LAFI was calculated by a previously validated formula. Primary outcome was late or clinically significant AF recurrence 3-12 months after CA. Baseline clinical, laboratory and echocardiographic variables were compared between the recurrence and non-recurrence groups.
Results: Study participants were middle aged (60+/10 years) and had a moderate-to-severe burden of cardiovascular comorbidities. 78 participants (46%) experienced late AF recurrence. Mean LAFI was 0.26+/-0.18. In multivariate analysis, lower LAFI was independently associated with the risk of recurrence (0.23 in recurrence group vs 0.29 in non-recurrence group, p \u3c 0.01). Predictive value of LAFI for AF recurrence was similar to CHADS2 score (c-statistic 0.60 vs 0.58, p 0.76). In subgroup of patients with persistent AF, LAFI predicted AF recurrence more strongly than CHADS2 score (c-statistic: 0.79 vs 0.58, p 0.02).
Conclusions: In our cohort of 170 participants with AF undergoing index CA ablation, we observed that LAFI related to late AF recurrence after CA, independent of the traditional risk factors. Since LAFI can be calculated from almost any traditional echocardiographic recording, our findings suggest that LAFI may help guide therapeutic decision-making regarding application of CA, particularly among challenging patients with symptomatic persistent AF
Estimating the Power of Indirect Comparisons: A Simulation Study
Indirect comparisons are becoming increasingly popular for evaluating medical treatments that have not been compared head-to-head in randomized clinical trials (RCTs). While indirect methods have grown in popularity and acceptance, little is known about the fragility of confidence interval estimations and hypothesis testing relying on this method.We present the findings of a simulation study that examined the fragility of indirect confidence interval estimation and hypothesis testing relying on the adjusted indirect method.Our results suggest that, for the settings considered in this study, indirect confidence interval estimation suffers from under-coverage while indirect hypothesis testing suffers from low power in the presence of moderate to large between-study heterogeneity. In addition, the risk of overestimation is large when the indirect comparison of interest relies on just one trial for one of the two direct comparisons.Indirect comparisons typically suffer from low power. The risk of imprecision is increased when comparisons are unbalanced
The OMERACT Core Domain Set for Clinical Trials of Shoulder Disorders.
OBJECTIVE:To reach consensus on the core domains to be included in a core domain set for clinical trials of shoulder disorders using the Outcome Measures in Rheumatology (OMERACT) Filter 2.1 Core Domain Set process. METHODS:At OMERACT 2018, the OMERACT Shoulder Working Group conducted a workshop that presented the OMERACT 2016 preliminary core domain set and its rationale based upon a systematic review of domains measured in shoulder trials and international Delphi sessions involving patients, clinicians, and researchers, as well as a new systematic review of qualitative studies on the experiences of people with shoulder disorders. After discussions in breakout groups, the OMERACT core domain set for clinical trials of shoulder disorders was presented for endorsement by OMERACT 2018 participants. RESULTS:The qualitative review (n = 8) identified all domains included in the preliminary core set. An additional domain, cognitive dysfunction, was also identified, but confidence that this represents a core domain was very low. The core domain set that was endorsed by the OMERACT participants, with 71% agreement, includes 4 "mandatory" trial domains: pain, function, patient global - shoulder, and adverse events including death; and 4 "important but optional" domains: participation (recreation/work), sleep, emotional well-being, and condition-specific pathophysiological manifestations. Cognitive dysfunction was voted out of the core domain set. CONCLUSION:OMERACT 2018 delegates endorsed a core domain set for clinical trials of shoulder disorders. The next step includes identification of a core outcome measurement set that passes the OMERACT 2.1 Filter for measuring each domain
Methods and processes for development of a CONSORT extension for reporting pilot randomized controlled trials.
BACKGROUND: Feasibility and pilot studies are essential components of planning or preparing for a larger randomized controlled trial (RCT). They are intended to provide useful information about the feasibility of the main RCT-with the goal of reducing uncertainty and thereby increasing the chance of successfully conducting the main RCT. However, research has shown that there are serious inadequacies in the reporting of pilot and feasibility studies. Reasons for this include a lack of explicit publication policies for pilot and feasibility studies in many journals, unclear definitions of what constitutes a pilot or feasibility RCT/study, and a lack of clarity in the objectives and methodological focus. All these suggest that there is an urgent need for new guidelines for reporting pilot and feasibility studies. OBJECTIVES: The aim of this paper is to describe the methods and processes in our development of an extension to the Consolidated Standards of Reporting Trials (CONSORT) Statement for reporting pilot and feasibility RCTs, that are executed in preparation for a future, more definitive RCT. METHODS/DESIGN: There were five overlapping parts to the project: (i) the project launch-which involved establishing a working group and conducting a review of the literature; (ii) stakeholder engagement-which entailed consultation with the CONSORT group, journal editors and publishers, the clinical trials community, and funders; (iii) a Delphi process-used to assess the agreement of experts on initial definitions and to generate a reporting checklist for pilot RCTs, based on the 2010 CONSORT statement extension applicable to reporting pilot studies; (iv) a consensus meeting-to discuss, add, remove, or modify checklist items, with input from experts in the field; and (v) write-up and implementation-which included a guideline document which gives an explanation and elaboration (E&E) and which will provide advice for each item, together with examples of good reporting practice. This final part also included a plan for dissemination and publication of the guideline. CONCLUSIONS: We anticipate that implementation of our guideline will improve the reporting completeness, transparency, and quality of pilot RCTs, and hence benefit several constituencies, including authors of journal manuscripts, funding agencies, educators, researchers, and end-users
Critical autobiography in the professional doctorate: improving students’ writing through the device of literature
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