2,572 research outputs found

    Quantifying the real life risk profile of inhaled corticosteroids in COPD by record linkage analysis

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    BACKGROUND: Inhaled corticosteroids (ICS), especially when prescribed in combination with long-acting β(2) agonists have been shown to improve COPD outcomes. Although there is consistent evidence linking ICS with adverse effects such as pneumonia, the complete risk profile is unclear with conflicting evidence on any association between ICS and the incidence or worsening of existing diabetes, cataracts and fractures. We investigated this using record linkage in a Dundee COPD population. METHODS: A record linkage study linking COPD and diabetes datasets with prescription, hospitalisation and mortality data via a unique Community Health Index (CHI) number. A Cox regression model was used to determine the association between ICS use and new diabetes or worsening of existing diabetes and hospitalisations for pneumonia, fractures or cataracts after adjusting for potential confounders. A time dependent analysis of exposure comparing time on versus off ICS was used to take into account patients changing their exposure status during follow-up and to prevent immortal time bias. RESULTS: 4305 subjects (3243 exposed to ICS, total of 17,229 person-years of exposure and 1062 non exposed, with a follow-up of 4,508 patient-years) were eligible for the study. There were 239 cases of new diabetes (DM) and 265 cases of worsening DM, 550 admissions for pneumonia, 288 hospitalisations for fracture and 505 cataract related admissions. The hazard ratio for the association between cumulative ICS and outcomes were 0.70 (0.43-1.12), 0.57 (0.24-1.37), 1.38 (1.09-1.74), 1.08 (0.73-1.59) and 1.42 (1.07-1.88) after multivariate analysis respectively. CONCLUSION: The use of ICS in our cohort was not associated with new onset of diabetes, worsening of existing diabetes or fracture hospitalisation. There was however an association with increased cataracts and pneumonia hospitalisations

    Molecular gas and dust around a radio-quiet quasar at redshift 4.69.

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    Galaxies are believed to have formed a large proportion of their stars in giant bursts of star formation early in their lives, but when and how this took place are still very uncertain. The presence of large amounts of dust in quasars and radio galaxies at redshifts z > 4 shows that some synthesis of heavy elements had already occurred at this time. This implies that molecular gas--the building material of stars--should also be present, as it is in galaxies at lower redshifts (z approximately = 2.5, refs 7-10). Here we report the detection of emission from dust and carbon monoxide in the radio-quiet quasar BR1202 - 0725, at redshift z = 4.69. Maps of these emissions reveal two objects, separated by a few arc seconds, which could indicated either the presence of a companion to the quasar or gravitational lensing of the quasar itself. Regardless of the precise interpretation of the maps, the detection of carbon monoxide confirms the presence of a large mass of molecular gas in one of the most distant galaxies known, and shows that conditions conducive to huge bursts of star formation existed in the very early Universe

    Neurotrophin gene augmentation by electrotransfer to improve cochlear implant hearing outcomes

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    This Review outlines the development of DNA-based therapeutics for treatment of hearing loss, and in particular, considers the potential to utilize the properties of recombinant neurotrophins to improve cochlear auditory (spiral ganglion) neuron survival and repair. This potential to reduce spiral ganglion neuron death and indeed re-grow the auditory nerve fibres has been the subject of considerable pre-clinical evaluation over decades with the view of improving the neural interface with cochlear implants. This provides the context for discussion about the development of a novel means of using cochlear implant electrode arrays for gene electrotransfer. Mesenchymal cells which line the cochlear perilymphatic compartment can be selectively transfected with (naked) plasmid DNA using array - based gene electrotransfer, termed ‘close-field electroporation’. This technology is able to drive expression of brain derived neurotrophic factor (BDNF) in the deafened guinea pig model, causing re-growth of the spiral ganglion peripheral neurites towards the mesenchymla cells, and hence into close proximity with cochlear implant electrodes within scala tympani. This was associated with functional enhancement of the cochlear implant neural interface (lower neural recruitment thresholds and expanded dynamic range, measured using electrically - evoked auditory brainstem responses). The basis for the efficiency of close-field electroporation arises from the compression of the electric field in proximity to the ganged cochlear implant electrodes. The regions close to the array with highest field strength corresponded closely to the distribution of bioreporter cells (adherent human embryonic kidney (HEK293)) expressing green fluorescent reporter protein (GFP) following gene electrotransfer. The optimization of the gene electrotransfer parameters using this cell-based model correlated closely with in vitro and in vivo cochlear gene delivery outcomes. The migration of the cochlear implant electrode array-based gene electrotransfer platform towards a clinical trial for neurotrophin-based enhancement of cochlear implants is supported by availability of a novel regulatory compliant mini-plasmid DNA backbone (pFAR4; plasmid Free of Antibiotic Resistance v.4) which could be used to package a ‘humanized’ neurotrophin expression cassette. A reporter cassette packaged into pFAR4 produced prominent GFP expression in the guinea pig basal turn perilymphatic scalae. More broadly, close-field gene electrotransfer may lend itself to a spectrum of potential DNA therapeutics applications benefitting from titratable, localised, delivery of naked DNA, for gene augmentation, targeted gene regulation, or gene substitution strategies

    Identity-by-descent filtering as a tool for the identification of disease alleles in exome sequence data from distant relatives

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    Large-scale, deep resequencing may be the next logical step in the genetic investigation of common complex diseases. Because each individual is likely to carry many thousands of variants, the identification of causal alleles requires an efficient strategy to reduce the number of candidate variants. Under many genetic models, causal alleles can be expected to reside within identity-by-descent (IBD) regions shared by affected relatives. In distant relatives, IBD regions constitute a small portion of the genome and can thus greatly reduce the search space for causal alleles. However, the effectiveness of this strategy is unknown. We test the simulated mini-exome data set in extended pedigrees provided by Genetic Analysis Workshop 17. At the fourth- and fifth-degree level of relatedness, case-case pairs shared between 1% and 9% of the genome identical by descent. As expected, no genes were shared identical by descent by all case subjects, but 43 genes were shared by many case subjects across at least 50 replicates. We filtered variants in these genes based on population frequency, function, informativeness, and evidence of association using the family-based association test. This analysis highlighted five genes previously implicated in triglyceride, lipid, and cholesterol metabolism. Comparison with the list of true risk alleles revealed that strict IBD filtering followed by association testing of the rarest alleles was the most sensitive strategy. IBD filtering may be a useful strategy for narrowing down the list of candidate variants in exome data, but the optimal degree of relatedness of affected pairs will depend on the genetic architecture of the disease under study

    Cost-Effectiveness of Magnetic Resonance Imaging with a New Contrast Agent for the Early Diagnosis of Alzheimer's Disease

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    Background: Used as contrast agents for brain magnetic resonance imaging (MRI), markers for beta-amyloid deposits might allow early diagnosis of Alzheimer’s disease (AD). We evaluated the cost-effectiveness of such a diagnostic test, MRI+CLP (contrastophore-linker-pharmacophore), should it become clinically available. Methodology/Principal Findings: We compared the cost-effectiveness of MRI+CLP to that of standard diagnosis using currently available cognition tests and of standard MRI, and investigated the impact of a hypothetical treatment efficient in early AD. The primary analysis was based on the current French context for 70-year-old patients with Mild Cognitive Impairment (MCI). In alternative ‘‘screen and treat’ ’ scenarios, we analyzed the consequences of systematic screenings of over-60 individuals (either population-wide or restricted to the ApoE4 genotype population). We used a Markov model of AD progression; model parameters, as well as incurred costs and quality-of-life weights in France were taken from the literature. We performed univariate and probabilistic multivariate sensitivity analyses. The base-case preferred strategy was the standard MRI diagnosis strategy. In the primary analysis however, MRI+CLP could become the preferred strategy under a wide array of scenarios involving lower cost and/or higher sensitivity or specificity. By contrast, in the ‘‘screen and treat’’ analyses, the probability of MRI+CLP becoming the preferred strategy remained lower than 5%. Conclusions/Significance: It is thought that anti-beta-amyloid compounds might halt the development of dementia i

    Practices, patients and (im)perfect data - feasibility of a randomised controlled clinical drug trial in German general practices

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    <p>Abstract</p> <p>Background</p> <p>Randomised controlled clinical (drug) trials supply high quality evidence for therapeutic strategies in primary care. Until now, experience with drug trials in German general practice has been sparse. In 2007/2008, the authors conducted an investigator-initiated, non-commercial, double-blind, randomised controlled pilot trial (HWI-01) to assess the clinical equivalence of ibuprofen and ciprofloxacin in the treatment of uncomplicated urinary tract infection (UTI). Here, we report the feasibility of this trial in German general practices and the implementation of Good Clinical Practice (GCP) standards as defined by the International Conference on Harmonisation (ICH) in mainly inexperienced general practices.</p> <p>Methods</p> <p>This report is based on the experience of the HWI-01 study conducted in 29 German general practices. Feasibility was defined by 1) successful practice recruitment, 2) sufficient patient recruitment, 3) complete and accurate data collection and 4) appropriate protection of patient safety.</p> <p>Results</p> <p>The final practice recruitment rate was 18%. In these practices, 79 of 195 screened UTI patients were enrolled. Recruitment differed strongly between practices (range 0-12, mean 2.8 patients per practice) and was below the recruitment goal of approximately 100 patients. As anticipated, practice nurses became the key figures in the screening und recruitment of patients. Clinical trial demands, in particular for completing symptom questionnaires, documentation of source data and reporting of adverse events, did not agree well with GPs' documentation habits and required support from study nurses. In many cases, GPs and practice staff seemed to be overwhelmed by the amount of information and regulations. No sudden unexpected serious adverse reactions (SUSARs) were observed during the trial.</p> <p>Conclusions</p> <p>To enable drug trials in general practice, it is necessary to adapt the setup of clinical research infrastructure to the needs of GPs and their practice staff. Risk adaption of clinical trial regulations is necessary to facilitate non-commercial comparative effectiveness trials in primary health care.</p> <p>Trial Registration</p> <p>Trial registration number: <a href="http://www.controlled-trials.com/ISRCTN00470468">ISRCTN00470468</a></p

    Refining the role of laparoscopy and laparoscopic ultrasound in the staging of presumed pancreatic head and ampullary tumours

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    Laparoscopy and laparoscopic ultrasound have been validated previously as staging tools for pancreatic cancer. The aim of this study was to identify if assessment of vascular involvement with abdominal computed tomography (CT) would allow refinement of the selection criteria for laparoscopy and laparoscopic ultrasound (LUS). The details of patients staged with LUS and abdominal CT were obtained from the unit's pancreatic cancer database. A CT grade (O, A-F) of vascular involvement was recorded by a single radiologist. Of 152 patients, who underwent a LUS, 56 (37%) had unresectable disease. Three of 26 (12%) patients with CT grade O, 27 of 88 (31%) patients with CT grade A to D, 17 of 29 (59%) patients with CT grade E and all nine patients with CT grade F were found to have unresectable disease. In all, 24% of patients with tumours <3 cm were found to have unresectable disease. In those patients with tumours considered unresectable, local vascular involvement was found in 56% of patients and vascular involvement with metastatic disease in 17%, while 20% of patients had liver metastases alone and 5% had isolated peritoneal metastases. The remaining patient was deemed unfit for resection. Selective use of laparoscopic ultrasound is indicated in the staging of periampullary tumours with CT grades A to D
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