1,092 research outputs found
The involvement of oncogenic DNA viruses in Hodgkin's disease
At the outset of this project Epstein-Barr virus (EBV) was associated with a proportion of cases of Hodgkin's disease (HD). Clonal EBV genomes were detected in HD tumour material however the localisation of EBV within the malignant cells had not been clearly demonstrated. Following the availability of monoclonal antibodies to the EBV latent genes, the expression of LMP-1 and EBNA-2 was investigated in a series of HD cases. EBV LMP-1 was expressed in Reed-Sternberg (RS) cells in the majority of cases studied, however there was a lack of expression of EBNA-2. The detection of LMP-1, which has been shown to have oncogenic potential, has strengthened the evidence that EBV is involved in the pathogenesis of a proportion of HD cases. These results indicated that a distinct pattern of EBV latent gene expression, designated Lat II, was observed in HD. As LMP-1 has been shown to upregulate a number of cellular genes, the expression of CD23 and bcl-2 in HD were examined. CD23 and bcl-2 were rarely detected in RS cells. There was no correlation between LMP-1 expression and the presence of CD23 or bcl-2. These results indicate that the role of EBV in HD is independent of the upregulation of CD23 and bcl-2. Further evidence that EBV is localised to RS cells in HD was obtained following the detection of EBER RNA in RS cells using an in situ hybridisation technique. Comparison of techniques to detect EBV in HD tumour material indicated that the EBER RNA in situ hybridisation assay was the most useful and reliable method of determining EBV latent infection. We have categorised HD cases which were EBV-positive by in situ assays or using Southern blot hybridisation for the detection of clonal EBV genomes as EBV-associated. Using tine above criteria the epidemiological features of HD were investigated with respect to EBV. Paediatric HD cases, in particular cases <10 years of age, older adults and cases of MCHD subtype were strongly EBV-associated. There was no evidence that EBV is a useful prognostic marker. Although the epidemiological features of HD suggest that young adult HD is most likely to be caused by an infectious agent our results indicated that these cases, in particular NSHD, were seldom EBV-positive. We have speculated that another virus may be involved in this age group. In order to eliminate the possibility that other known DNA viruses may be involved in HD, we examined clinical samples from HD, NHL and reactive conditions for the presence of adenovirus, SV40, LPV and HHV-7. We have not detected any of the viruses in these clinical samples. The implications of these results will be discussed further in this thesis
Mitigating the risk of Zika virus contamination of raw materials and cell lines in the manufacture of biologicals
Ensuring the virological safety of biologicals is challenging due to the risk of viral contamination of raw materials and cell
banks, and exposure during in-process handling to known and/or emerging viral pathogens. Viruses may contaminate raw
materials and biologicals intended for human or veterinary use and remain undetected until appropriate testing measures
are employed. The outbreak and expansive spread of the mosquito-borne flavivirus Zika virus (ZIKV) poses challenges to
screening human- and animal -derived products used in the manufacture of biologicals. Here, we report the results of an in
vitro study where detector cell lines were challenged with African and Asian lineages of ZIKV. We demonstrate that this
pathogen is robustly detectable by in vitro assay, thereby providing assurance of detection of ZIKV, and in turn underpinning
the robustness of in vitro virology assays in safety testing of biologicals
A systematic review of interventions aimed at increasing physical activity in adults with chronic musculoskeletal pain—protocol
BackgroundChronic musculoskeletal pain is highly prevalent, affecting around one in five people across Europe. Osteoarthritis, low back pain, neck pain and other musculoskeletal disorders are leading causes of disability worldwide and the most common source of chronic pain. Exercise and/or physical activity interventions have the potential to address not only the pain and disability associated with chronic pain but also the increased risk of morbidity and mortality seen in this population. Although exercise and/or physical activity is widely recommended, there is currently a paucity of research that offers an evidence base upon which the development or optimisation of interventions can be based. This systematic review will investigate the components of interventions associated with changes in physical activity levels in adults with chronic musculoskeletal pain.Methods/DesignThis systematic review will be reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidance. Randomised and quasi-randomised controlled trials of interventions aimed at increasing physical activity in adults with chronic musculoskeletal pain will be included. Articles will be identified through a comprehensive search of the following databases: CENTRAL in the Cochrane Library, the Cochrane Database of Systematic Reviews (CDSR), MEDLINE, Embase, CINAHL, PsycINFO and AMED. Two review authors will independently screen articles retrieved from the search for eligibility, extract relevant data on methodological issues and code interventions according to the behaviour change technique taxonomy (v1) of 93 hierarchically clustered techniques. As complex healthcare interventions can be modified by a wide variety of factors, data will be summarised statistically when the data are available, are sufficiently similar and are of sufficient quality. A narrative synthesis will be completed if there is insufficient data to permit a formal meta-analysis.DiscussionThis review will be of value to clinicians working in chronic pain services and to researchers involved in designing and evaluating interventions.Systematic review registrationPROSPERO reference:CRD42014010640
Inferring school district learning modalities during the COVID-19 pandemic with a hidden Markov model
In this study, learning modalities offered by public schools across the
United States were investigated to track changes in the proportion of schools
offering fully in-person, hybrid and fully remote learning over time. Learning
modalities from 14,688 unique school districts from September 2020 to June 2021
were reported by Burbio, MCH Strategic Data, the American Enterprise
Institute's Return to Learn Tracker and individual state dashboards. A model
was needed to combine and deconflict these data to provide a more complete
description of modalities nationwide.
A hidden Markov model (HMM) was used to infer the most likely learning
modality for each district on a weekly basis. This method yielded higher
spatiotemporal coverage than any individual data source and higher agreement
with three of the four data sources than any other single source. The model
output revealed that the percentage of districts offering fully in-person
learning rose from 40.3% in September 2020 to 54.7% in June of 2021 with
increases across 45 states and in both urban and rural districts. This type of
probabilistic model can serve as a tool for fusion of incomplete and
contradictory data sources in support of public health surveillance and
research efforts.Comment: 25 pages, 4 figure
Trial Protocol: Using genotype to tailor prescribing of nicotine replacement therapy: a randomised controlled trial assessing impact of communication upon adherence.
BACKGROUND: The behavioural impact of pharmacogenomics is untested; informing smokers of genetic test results for responsiveness to smoking cessation medication may increase adherence to this medication. The objective of this trial is to estimate the impact upon adherence to nicotine replacement therapy (NRT) of informing smokers that their oral dose of NRT has been tailored to a DNA analysis. Hypotheses to be tested are as follows: I Adherence to NRT is greater among smokers informed that their oral dose of NRT is tailored to an analysis of DNA (genotype), compared to one tailored to nicotine dependence questionnaire score (phenotype). II Amongst smokers who fail to quit at six months, motivation to make another quit attempt is lower when informed that their oral dose of NRT was tailored to genotype rather than phenotype. METHODS/DESIGN: An open label, parallel groups randomised trial in which 630 adult smokers (smoking 10 or more cigarettes daily) using National Health Service (NHS) stop smoking services in primary care are randomly allocated to one of two groups:i. NRT oral dose tailored by DNA analysis (OPRM1 gene) (genotype), orii. NRT oral dose tailored by nicotine dependence questionnaire score (phenotype)The primary outcome is proportion of prescribed NRT consumed in the first 28 days following an initial quit attempt, with the secondary outcome being motivation to make another quit attempt, amongst smokers not abstinent at six months. Other outcomes include adherence to NRT in the first seven days and biochemically validated smoking abstinence at six months. The primary outcome will be collected on 630 smokers allowing sufficient power to detect a 7.5% difference in mean proportion of NRT consumed using a two-tailed test at the 5% level of significance between groups. The proportion of all NRT consumed in the first four weeks of quitting will be compared between arms using an independent samples t-test and by estimating the 95% confidence interval for observed between-arm difference in mean NRT consumption (Hypothesis I). Motivation to make another quit attempt will be compared between arms in those failing to quit by six months (Hypothesis II). DISCUSSION: This is the first clinical trial evaluating the behavioural impact on adherence of prescribing medication using genetic rather than phenotypic information. Specific issues regarding the choice of design for trials of interventions of this kind are discussed. TRIAL DETAILS: Funder: Medical Research Council (MRC)Grant number: G0500274. ISRCTN: 14352545. Date trial stated: June 2007. Expected end date: December 2009. Expected reporting date: December 2010.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
The effectiveness of interventions aimed at increasing physical activity in adults with persistent musculoskeletal pain: a systematic review and meta-analysis
BackgroundIndividuals with persistent musculoskeletal pain (PMP) have an increased risk of developing co-morbid health conditions and for early-mortality compared to those without pain. Despite irrefutable evidence supporting the role of physical activity in reducing these risks; there has been limited synthesis of the evidence, potentially impacting the optimisation of these forms of interventions. This review examines the effectiveness of interventions in improving levels of physical activity and the components of these interventions.MethodsRandomised and quasi-randomised controlled trials were included in this review. The following databases were searched from inception to March 2016: CENTRAL in the Cochrane Library, Cochrane Database of Systematic Reviews (CDSR), MEDLINE, Embase, CINAHL, PsycINFO and AMED. Two reviewers independently screened citations, assessed eligibility, extracted data, assessed risk of bias and coded intervention content using the behaviour change taxonomy (BCTTv1) of 93 hierarchically clustered techniques. GRADE was used to rate the quality of the evidence.ResultsThe full text of 276 articles were assessed for eligibility, twenty studies involving 3441 participants were included in the review. Across the studies the mean number of BCTs coded was eight (range 0–16); with ‘goal setting’ and ‘instruction on how to perform the behaviour’ most frequently coded. For measures of subjective physical activity: interventions were ineffective in the short term, based on very low quality evidence; had a small effect in the medium term based on low quality evidence (SMD 0.25, 95% CI 0.01 to 0.48) and had a small effect in the longer term (SMD 0.21 95% CI 0.08 to 0.33) based on moderate quality evidence. For measures of objective physical activity: interventions were ineffective - based on very low to low quality evidence.ConclusionsThere is some evidence supporting the effectiveness of interventions in improving subjectively measured physical activity however, the evidence is mostly based on low quality studies and the effects are small. Given the quality of the evidence, further research is likely/very likely to have an important impact on our confidence in effect estimates and is likely to change the estimates. Future studies should provide details on intervention components and incorporate objective measures of physical activity
Group interventions to improve health outcomes : a framework for their design and delivery
Peer reviewedPublisher PD
Utilizing "Omic" technologies to identify and prioritize novel sources of resistance to the oomycete pathogen <i>Phytophthora infestans</i> in potato germplasm collections
The biggest threat to potato production world-wide is late blight, caused by the oomycete pathogen Phytophthora infestans. A screen of 126 wild diploid Solanum accessions from the Commonwealth Potato Collection (CPC) with P. infestans isolates belonging to the genotype 13-A2 identified resistances in the species S. bulbocastanum, S. capsicibaccatum, S. microdontum, S. mochiquense, S. okadae, S. pinnatisectum, S. polyadenium, S. tarijense and S. verrucosum. Effector-omics, allele mining and diagnostic RenSeq (dRenSeq) were utilized to investigate the nature of resistances in S. okadae accessions. dRenSeq in resistant S. okadae accessions 7129, 7625, 3762 and a bulk of 20 resistant progeny confirmed the presence of full-length Rpi-vnt1.1 under stringent mapping conditions and corroborated allele mining results in the accessions 7129 and 7625 as well as Avr-vnt1 recognition in transient expression assays. In contrast, susceptible S. okadae accession 3761 and a bulk of 20 susceptible progeny lacked sequence homology in the 5’ end compared to the functional Rpi-vnt1.1 gene. Further evaluation of S. okadae accessions with late blight isolates that have a broad spectrum of virulence demonstrated that, although S. okadae accessions 7129, 7625 and 7629 contain functional Rpi-vnt1.1, they also carry a novel resistance gene. We provide evidence that existing germplasm collection are important sources of novel resistances and that ‘omic’ technologies such as dRenSeq-based genomics and effector-omics are efficacious tools to rapidly explore the diversity within these collections
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Effect of varying skin surface electrode position on electroretinogram responses recorded using a handheld stimulating and recording system
Purpose
A handheld device (the RETeval system, LKC Technologies) aims to increase the ease of electroretinogram (ERG) recording by using specially designed skin electrodes, rather than corneal electrodes. We explored effects of electrode position on response parameters recorded using this device.
Methods
Healthy adult twins were recruited from the TwinsUK cohort and underwent recording of light-adapted flicker ERGs (corresponding to international standard stimuli). In Group 1, skin electrodes were placed in a “comfortable” position, which was up to 20 mm below the lid margin. For subsequent participants (Group 2), the electrode was positioned 2 mm from the lid margin as recommended by the manufacturer. Amplitudes and peak times (averaged from both eyes) were compared between groups after age-matching and inclusion of only one twin per pair. Light-adapted flicker and flash ERGs were recorded for an additional 10 healthy subjects in two consecutive recording sessions: in the test eye, electrode position was varied from 2 to 10–20 mm below the lid margin between sessions; in the fellow (control) eye, the electrode was 2 mm below the lid margin throughout. Amplitudes and peak times (test eye normalised to control eye) were compared for the two sessions.
Results
Including one twin per pair, and age-matching yielded 28 individuals per group. Flicker ERG amplitudes were significantly lower for Group 1 than Group 2 participants (p = 0.0024). However, mean peak times did not differ between groups (p = 0.54). For the subjects in whom electrode position was changed between recording sessions, flash and flicker amplitudes were significantly lower when positioned further from the lid margin (p 0.5).
Conclusions
Moving the skin electrodes further from the lid margin significantly reduces response amplitudes, highlighting the importance of consistent electrode positioning. However, this does not significantly affect peak times. Thus, it may be feasible to adopt a more comfortable position in participants who cannot tolerate the recommended position if analysis is restricted to peak time parameters
Engineered neural tissue for peripheral nerve repair
A new combination of tissue engineering techniques provides a simple and effective method for building aligned cellular biomaterials. Self-alignment of Schwann cells within a tethered type-1 collagen matrix, followed by removal of interstitial fluid produces a stable tissue-like biomaterial that recreates the aligned cellular and extracellular matrix architecture associated with nerve grafts. Sheets of this engineered neural tissue supported and directed neuronal growth in a co-culture model, and initial in vivo tests showed that a device containing rods of rolled-up sheets could support neuronal growth during rat sciatic nerve repair (5 mm gap). Further testing of this device for repair of a critical-sized 15 mm gap showed that, at 8 weeks, engineered neural tissue had supported robust neuronal regeneration across the gap. This is, therefore, a useful new approach for generating anisotropic engineered tissues, and it can be used with Schwann cells to fabricate artificial neural tissue for peripheral nerve repair
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