148 research outputs found
Increased prevalence of potential right-to-left shunting in children with sickle cell anaemia and stroke
'Paradoxical' embolization via intracardiac or intrapulmonary right-to-left shunts (RLS) is an established cause of stroke. Hypercoagulable states and increased right heart pressure, which both occur in sickle cell anaemia (SCA), predispose to paradoxical embolization. We hypothesized that children with SCA and overt stroke (SCA + stroke) have an increased prevalence of potential RLS. We performed contrasted transthoracic echocardiograms on 147 children (aged 2-19 years) with SCA + stroke) mean age 12·7 ± 4·8 years, 54·4% male) and a control group without SCA or stroke (n = 123; mean age 12·1 ± 4·9 years, 53·3% male). RLS was defined as any potential RLS detected by any method, including intrapulmonary shunting. Echocardiograms were masked and adjudicated centrally. The prevalence of potential RLS was significantly higher in the SCA+stroke group than controls (45·6% vs. 23·6%, P < 0·001). The odds ratio for potential RLS in the SCA + stroke group was 2·7 (95% confidence interval: 1·6-4·6) vs controls. In post hoc analyses, the SCA + stroke group had a higher prevalence of intrapulmonary (23·8% vs. 5·7%, P < 0·001) but not intracardiac shunting (21·8% vs. 18·7%, P = 0·533). SCA patients with potential RLS were more likely to report headache at stroke onset than those without. Intrapulmonary and intracardiac shunting may be an overlooked, independent and potentially modifiable risk factor for stroke in SCA
The Challenges, Opportunities, and Imperative of Structured Reporting in Medical Imaging
Despite dramatic innovation in medical imaging and information system technologies, the radiology report has remained stagnant for more than a century. Structured reporting was created in the hopes of addressing well-documented deficiencies in report content and organization but has largely failed in its adoption due to concerns over workflow and productivity. A number of political, economical, and clinical quality-centric initiatives are currently taking place within medicine which will dramatically change the medical landscape including Pay for Performance, Evidence-Based Medicine, and the Physician Quality Reporting Initiative. These will collectively enhance efforts to improve quality in reporting, stimulate new technology development, and counteract the impending threat of commoditization within radiology. Structured reporting offers a number of unique opportunities and advantages over traditional free text reporting and will provide a means for the radiology community to add value to its most important service deliverable the radiology report
The late radiotherapy normal tissue injury phenotypes of telangiectasia, fibrosis and atrophy in breast cancer patients have distinct genotype-dependent causes
The relationship between late normal tissue radiation injury phenotypes in 167 breast cancer patients treated with radiotherapy and: (i) radiotherapy dose (boost); (ii) an early acute radiation reaction and (iii) genetic background was examined. Patients were genotyped at single nucleotide polymorphisms (SNPs) in eight candidate genes. An early acute reaction to radiation and/or the inheritance of the transforming growth factor-β1 (TGFβ1 −509T) SNP contributed to the risk of fibrosis. In contrast, an additional 15 Gy electron boost and/or the inheritance of X-ray repair cross-complementing 1 (XRCC1) (R399Q) SNP contributed to the risk of telangiectasia. Although fibrosis, telangiectasia and atrophy, all contribute to late radiation injury, the data suggest that they have distinct underlying genetic and radiobiological causes. Fibrosis risk is associated with an inflammatory response (an acute reaction and/or TGFβ1), whereas telangiectasia is associated with vascular endothelial cell damage (boost and/or XRCC1). Atrophy is associated with an acute response, but the genetic predisposing factors that determine the risk of an acute response or atrophy have yet to be identified. A combined analysis of two UK breast cancer patient studies shows that 8% of patients are homozygous (TT) for the TGFβ1 (C-509T) variant allele and have a 15-fold increased risk of fibrosis following radiotherapy (95% confidence interval: 3.76–60.3; P=0.000003) compared with (CC) homozygotes
Rapid intrapartum test for maternal group B streptococcal colonisation and its effect on antibiotic use in labouring women with risk factors for early-onset neonatal infection (GBS2): cluster randomised trial with nested test accuracy study
Background: Mother-to-baby transmission of group B Streptococcus (GBS) is the main cause of early-onset infection. We evaluated whether, in women with clinical risk factors for early neonatal infection, the use of point-of-care rapid intrapartum test to detect maternal GBS colonisation reduces maternal antibiotic exposure compared with usual care, where antibiotics are administered due to those risk factors. We assessed the accuracy of the rapid test in diagnosing maternal GBS colonisation, against the reference standard of selective enrichment culture. Methods: We undertook a parallel-group cluster randomised trial, with nested test accuracy study and microbiological sub-study. UK maternity units were randomised to a strategy of rapid test (GeneXpert GBS system, Cepheid) or usual care. Within units assigned to rapid testing, vaginal-rectal swabs were taken from women with risk factors for vertical GBS transmission in established term labour. The trial primary outcome was the proportion of women receiving intrapartum antibiotics to prevent neonatal early-onset GBS infection. The accuracy of the rapid test was compared against the standard of selective enrichment culture in diagnosing maternal GBS colonisation. Antibiotic resistance profiles were determined in paired maternal and infant samples. Results: Twenty-two maternity units were randomised and 20 were recruited. A total of 722 mothers (749 babies) participated in rapid test units; 906 mothers (951 babies) were in usual care units. There was no evidence of a difference in the rates of intrapartum antibiotic prophylaxis (relative risk 1.16, 95% CI 0.83 to 1.64) between the rapid test (41%, 297/716) and usual care (36%, 328/906) units. No serious adverse events were reported. The sensitivity and specificity measures of the rapid test were 86% (95% CI 81 to 91%) and 89% (95% CI 85 to 92%), respectively. Babies born to mothers who carried antibiotic-resistant Escherichia coli were more likely to be colonised with antibiotic-resistant strains than those born to mothers with antibiotic-susceptible E. coli. Conclusion: The use of intrapartum rapid test to diagnose maternal GBS colonisation did not reduce the rates of antibiotics administered for preventing neonatal early-onset GBS infection than usual care, although with considerable uncertainty. The accuracy of the rapid test is within acceptable limits. Trial registration: ISRCTN74746075. Prospectively registered on 16 April 2015
Genomic analysis of Acidianus hospitalis W1 a host for studying crenarchaeal virus and plasmid life cycles
The Acidianus hospitalis W1 genome consists of a minimally sized chromosome of about 2.13 Mb and a conjugative plasmid pAH1 and it is a host for the model filamentous lipothrixvirus AFV1. The chromosome carries three putative replication origins in conserved genomic regions and two large regions where non-essential genes are clustered. Within these variable regions, a few orphan orfB and other elements of the IS200/607/605 family are concentrated with a novel class of MITE-like repeat elements. There are also 26 highly diverse vapBC antitoxin–toxin gene pairs proposed to facilitate maintenance of local chromosomal regions and to minimise the impact of environmental stress. Complex and partially defective CRISPR/Cas/Cmr immune systems are present and interspersed with five vapBC gene pairs. Remnants of integrated viral genomes and plasmids are located at five intron-less tRNA genes and several non-coding RNA genes are predicted that are conserved in other Sulfolobus genomes. The putative metabolic pathways for sulphur metabolism show some significant differences from those proposed for other Acidianus and Sulfolobus species. The small and relatively stable genome of A. hospitalis W1 renders it a promising candidate for developing the first Acidianus genetic systems
The development, design, testing, refinement, simulation and application of an evaluation framework for communities of practice and social-professional networks
Background. Communities of practice and social-professional networks are generally considered to enhance workplace experience and enable organizational success. However, despite the remarkable growth in interest in the role of collaborating structures in a range of industries, there is a paucity of empirical research to support this view. Nor is there a convincing model for their systematic evaluation, despite the significant potential benefits in answering the core question: how well do groups of professionals work together and how could they be organised to work together more effectively? This research project will produce a rigorous evaluation methodology and deliver supporting tools for the benefit of researchers, policymakers, practitioners and consumers within the health system and other sectors. Given the prevalence and importance of communities of practice and social networks, and the extent of investments in them, this project represents a scientific innovation of national and international significance. Methods and design. Working in four conceptual phases the project will employ a combination of qualitative and quantitative methods to develop, design, field-test, refine and finalise an evaluation framework. Once available the framework will be used to evaluate simulated, and then later existing, health care communities of practice and social-professional networks to assess their effectiveness in achieving desired outcomes. Peak stakeholder groups have agreed to involve a wide range of members and participant organisations, and will facilitate access to various policy, managerial and clinical networks. Discussion. Given its scope and size, the project represents a valuable opportunity to achieve breakthroughs at two levels; firstly, by introducing novel and innovative aims and methods into the social research process and, secondly, through the resulting evaluation framework and tools. We anticipate valuable outcomes in the improved understanding of organisational performance and delivery of care. The project's wider appeal lies in transferring this understanding to other health jurisdictions and to other industries and sectors, both nationally and internationally. This means not merely publishing the results, but contextually interpreting them, and translating them to advance the knowledge base and enable widespread institutional and organisational application
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