53 research outputs found

    Improving the Quality of Dentistry (IQuaD):a cluster factorial randomised controlled trial comparing the effectiveness and cost-benefit of oral hygiene advice and/or periodontal instrumentation with routine care for the prevention and management of periodontal disease in dentate adults attending dental primary care

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    Acknowledgements The authors wish to thank Mark Forrest and the programming team at CHaRT; Cynthia Fraser, our information specialist, for assistance with referencing; Moira Swan, who was the dental research nurse and part of the OA team in Newcastle upon Tyne; Louise Campbell for secretarial support and data management; our original statistician in the group, Andy Elders; senior IT manager Gladys Macpherson; senior trial administrator at the TCOD Marilyn Laird; Luke Vale for his involvement with the design of the health economic analysis at the inception of the trial; Maria Dimitrova, who assisted the health economists in the collection of unit costs; staff of the Scottish Primary Care Research Network, who assisted with screening eligible patients at dental practices; staff of the North East Commissioning Support Unit who assisted with research payments to dental practices in the north-east; members of the TMC and Periodontal Advisory Group for their ongoing advice and support of the trial; the independent members of the TSC and DMC; and the staff at recruitment sites who facilitated recruitment, treatment and follow-up of trial participants. The Health Services Research Unit and the Health Economics Research Unit is core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate.Peer reviewedPublisher PD

    Localization of type 1 diabetes susceptibility to the MHC class I genes HLA-B and HLA-A

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    The major histocompatibility complex (MHC) on chromosome 6 is associated with susceptibility to more common diseases than any other region of the human genome, including almost all disorders classified as autoimmune. In type 1 diabetes the major genetic susceptibility determinants have been mapped to the MHC class II genes HLA-DQB1 and HLA-DRB1 (refs 1-3), but these genes cannot completely explain the association between type 1 diabetes and the MHC region. Owing to the region's extreme gene density, the multiplicity of disease-associated alleles, strong associations between alleles, limited genotyping capability, and inadequate statistical approaches and sample sizes, which, and how many, loci within the MHC determine susceptibility remains unclear. Here, in several large type 1 diabetes data sets, we analyse a combined total of 1,729 polymorphisms, and apply statistical methods - recursive partitioning and regression - to pinpoint disease susceptibility to the MHC class I genes HLA-B and HLA-A (risk ratios >1.5; Pcombined = 2.01 × 10-19 and 2.35 × 10-13, respectively) in addition to the established associations of the MHC class II genes. Other loci with smaller and/or rarer effects might also be involved, but to find these, future searches must take into account both the HLA class II and class I genes and use even larger samples. Taken together with previous studies, we conclude that MHC-class-I-mediated events, principally involving HLA-B*39, contribute to the aetiology of type 1 diabetes. ©2007 Nature Publishing Group

    Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function

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    Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes

    Randomized factorial trial of esomeprazole and aspirin in Barrett’s oesophagus: the Aspirin and Esomeprazole Chemoprevention in Barrett’s metaplasia Trial (AspECT)

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    Background: Oesophageal adenocarcinoma (OA) is the sixth commonest cause of cancer death worldwide and Barrett’s oesophagus (BO) is the most significant risk factor. We evaluated the efficacy of high-dose esomeprazole proton pump inhibitor acid suppression (PPI) and aspirin in improving outcome for BO patients in the largest such randomized controlled trial. Methods: Patients with ≥1cm BO in UK and Canadian hospitals were randomized 1:1:1:1 using a computer-generated schedule held in a central trials unit in a 2X2 factorial design to high-dose (40mg twice-daily) or low-dose (20mg once-daily) PPI, alone or with aspirin (UK: 300mg/day, Canada: 325mg/day), unblinded (reporting pathologists blinded). The primary composite endpoint was time to all-cause mortality, OA, or high-grade dysplasia, analysed using accelerated failure time modelling adjusted for minimization factors (age, BO length, intestinal metaplasia). Findings: Recruited patients (N=2557) were followed for 8·9 years (median; interquartile range 8·2–9·8), collecting 20,095 follow-up years and 99·9% of planned data. There were 313 primary events. High-dose PPI was superior to low-dose PPI (p=0·037, N=1265 (low dose), N=1270 (high dose), time ratio (TR)=1·27, 95%CI=1·01–1·58). Aspirin was not significantly better than no aspirin (p=0·068, N=1142 (no aspirin), N = 1138 (aspirin), TR=1·24, 95%CI=0·98–1·57). If patients using NSAIDs were censored at time of first use,aspirin was significantly better than no Aspirin (p=0·043, N=2,236, TR=1·29 95%CI=1·01– 1·66). Combining high-dose PPI with aspirin had the strongest effect compared with low dose PPI without aspirin (p=0·0068, TR=1·59, 95%CI=1·14–2·23). NNT for PPI and aspirin benefit is 34 and 43, respectively. Only 1·0% (28) of participants reported study-treatment related serious adverse events. Interpretation: High-dose PPI and aspirin chemoprevention therapy, especially in combination, significantly and safely improve outcome in BO patients

    Structure-function studies of P2X receptors

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    P2X receptors are fast, ATP-gated cation ion channels. To date seven subtypes of P2X receptors have been cloned and identified, PZXH. The membrane topology of the P2X subunit consists of intracellular amino- and carboxy-termini, two transmembrane spanning domains and a large extracellular loop. Despite similar membrane topology, within this family of receptors the P2X subtypes possess different functional characteristics. They exhibit different sensitivities to agonists and antagonists, are modulated differently by extracellular ions, and have different pore forming abilities. The regions that are responsible for differences in function between P2X subtypes have not been elucidated. This thesis aims to further knowledge regarding the relationship between the structure of the P2X family and differences in the function of the various receptor subtypes. Examination of the primary structure of the P2X receptor family led to the identification of epitope regions suitable for antibody production. This suite of antibodies was tested for specificity and the distribution of P2X receptors was examined in a range of rat tissues and two cell lines. The pathophysiological involvement of the P2X7 receptor was examined in B-CLL patients. Two polymorphisms as well as a loss of function mutation were identified in both normal and leukaemic populations. The site of agonist binding is believed to be within the extracellular loop. Examination of the primary structure of the human cytolytic receptor P2X7 led to the identification of two noncontiguous regions that could potentially be involved in binding ATP. Three amino acid residues that lie within the extracellular loop were targeted and their involvement in ATP binding was determined. Two lysine residues at positions 193 and 31 1 and a proline residue at 210 were each exchanged with alanine. An abolition of function of human receptors with mutations at positions 193 or 311 was observed, consistent with a disruption of the ATP binding domain, although alterations in transduction or gating cannot be dismissed. The P2X receptor appears to be comprised of a trimeric subunit arrangement, and Hill coefficients of between 1 and 3 reported for ATP binding suggest that there is more than one ATP binding site per functional receptor. Modelling of the putative binding cleft of the hP2X7 subunit was performed and the residues important for ATP binding were highlighted. The fimctional trimeric receptor appears to possess three intersubunit ATP binding sites. In an attempt to isolate regions of the extracellular domain that contribute to or control various channel properties, chimaeras between subtypes P2X], P2X4 and P2X7 were constructed and their properties examined. Each of the six chimaeras has been shown to be correctly inserted into the cell membrane and functional. These constructs will continue to be investigated and form the basis for extensive future work

    Strength and Physical Fitness Predict the Perception of Looming Sounds

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    Listeners consistently perceive approaching sounds to be closer than they actually are and perceptually underestimate the time to arrival of looming sound sources. In a natural environment, this underestimation results in more time than expected to evade or engage the source and affords a margin of safety that may provide a selective advantage. However, a key component in the proposed evolutionary origins of the perceptual bias is the appropriate timing of anticipatory motor behaviors. Here we show that listeners with poorer physical fitness respond sooner to looming sounds and with a larger margin of safety than listeners with better physical fitness. The anticipatory perceptual bias for looming sounds is negatively correlated with physical strength and positively correlated with recovery heart rate (a measure of aerobic fitness). The results suggest that the auditory perception of looming sounds may be modulated by the response capacity of the motor system. © 2012 Elsevier Inc
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