56 research outputs found

    Cardiac Potassium Channels: Physiological Insights for Targeted Therapy.

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    The development of novel drugs specifically directed at the ion channels underlying particular features of cardiac action potential (AP) initiation, recovery, and refractoriness would contribute to an optimized approach to antiarrhythmic therapy that minimizes potential cardiac and extracardiac toxicity. Of these, K(+) channels contribute numerous and diverse currents with specific actions on different phases in the time course of AP repolarization. These features and their site-specific distribution make particular K(+) channel types attractive therapeutic targets for the development of pharmacological agents attempting antiarrhythmic therapy in conditions such as atrial fibrillation. However, progress in the development of such temporally and spatially selective antiarrhythmic drugs against particular ion channels has been relatively limited, particularly in view of our incomplete understanding of the complex physiological roles and interactions of the various ionic currents. This review summarizes the physiological properties of the main cardiac potassium channels and the way in which they modulate cardiac electrical activity and then critiques a number of available potential antiarrhythmic drugs directed at them

    Can oral corticosteroids reduce the severity or duration of an acute cough, and the associated National Health Service and societal costs, in adults presenting to primary care?: study protocol for a randomised controlled trial

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    Background: Acute lower respiratory tract infection (LRTI) is one of the most common conditions managed internationally and is costly to health services and patients. Despite good evidence that antibiotics are not effective for improving the symptoms of uncomplicated LRTI, they are widely prescribed, contributing to antimicrobial resistance. Many of the symptoms observed in LRTI are mediated by inflammatory processes also observed in exacerbations of asthma, for which there is strong evidence of corticosteroid effectiveness. The primary aim of the OSAC (Oral Steroids for Acute Cough) Trial is to determine whether oral prednisolone (40 mg daily for 5 days) can reduce the duration of moderately bad (or worse) cough and the severity of all its associated symptoms on days 2 to 4 post-randomisation (day 1 is trial entry) by at least 20% in adults ≥18 years with acute LRTI presenting to primary care. Methods/design: OSAC is a two-arm, multi-centre, placebo-controlled, randomised superiority trial. The target sample size is 436 patients, which allows for a 20% dropout rate. Patients will be recruited from primary care sites (General Practitioner surgeries) across England and followed up until symptom resolution. The two primary clinical outcomes are the duration of moderately bad (or worse) cough, and the severity of all its associated symptoms on days 2 to 4 post-randomisation. Secondary outcomes include: antibiotic consumption; symptom burden; adverse events; participant satisfaction with treatment and intention to consult for future similar illnesses. A parallel economic evaluation will investigate the cost-effectiveness of the intervention. Discussion: Results from the OSAC trial will increase knowledge regarding the clinical and cost-effectiveness of corticosteroids for LRTI, and will establish the potential of a new treatment option that could substantially improve patient health. We have chosen a relatively high ‘efficacy dose’ as this will enable us to decide on the potential for further research into lower dose oral and/or inhaled corticosteroids. This trial will also contribute to a growing body of research investigating the natural course of this very common illness, as well as the effects of steroids on the undesirable inflammatory symptoms associated with infection. Trial registration: Current Controlled Trials ISRCTN57309858 (31 January 2013)

    Bax-Induced Apoptosis in Leber's Congenital Amaurosis: A Dual Role in Rod and Cone Degeneration

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    Pathogenesis in the Rpe65−/− mouse model of Leber's congenital amaurosis (LCA) is characterized by a slow and progressive degeneration of the rod photoreceptors. On the opposite, cones degenerate rapidly at early ages. Retinal degeneration in Rpe65−/− mice, showing a null mutation in the gene encoding the retinal pigment epithelium 65-kDa protein (Rpe65), was previously reported to depend on continuous activation of a residual transduction cascade by unliganded opsin. However, the mechanisms of apoptotic signals triggered by abnormal phototransduction remain elusive. We previously reported that activation of a Bcl-2-dependent pathway was associated with apoptosis of rod photoreceptors in Rpe65−/− mice during the course of the disease. In this study we first assessed whether activation of Bcl-2-mediated apoptotic pathway was dependent on constitutive activation of the visual cascade through opsin apoprotein. We then challenged the direct role of pro-apoptotic Bax protein in triggering apoptosis of rod and cone photoreceptors

    Integrative epigenomics, transcriptomics and proteomics of patient chondrocytes reveal genes and pathways involved in osteoarthritis.

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    Osteoarthritis (OA) is a common disease characterized by cartilage degeneration and joint remodeling. The underlying molecular changes underpinning disease progression are incompletely understood. We investigated genes and pathways that mark OA progression in isolated primary chondrocytes taken from paired intact versus degraded articular cartilage samples across 38 patients undergoing joint replacement surgery (discovery cohort: 12 knee OA, replication cohorts: 17 knee OA, 9 hip OA patients). We combined genome-wide DNA methylation, RNA sequencing, and quantitative proteomics data. We identified 49 genes differentially regulated between intact and degraded cartilage in at least two -omics levels, 16 of which have not previously been implicated in OA progression. Integrated pathway analysis implicated the involvement of extracellular matrix degradation, collagen catabolism and angiogenesis in disease progression. Using independent replication datasets, we showed that the direction of change is consistent for over 90% of differentially expressed genes and differentially methylated CpG probes. AQP1, COL1A1 and CLEC3B were significantly differentially regulated across all three -omics levels, confirming their differential expression in human disease. Through integration of genome-wide methylation, gene and protein expression data in human primary chondrocytes, we identified consistent molecular players in OA progression that replicated across independent datasets and that have translational potential.National Institute for Health Research (Cambridge BRC

    The Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of prostate carcinoma

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    Prostate cancer is the most commonly diagnosed malignancy and second leading cause of cancer death among men in the United States. In recent years, several new agents, including cancer immunotherapies, have been approved or are currently being investigated in late-stage clinical trials for the management of advanced prostate cancer. Therefore, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel, including physicians, nurses, and patient advocates, to develop consensus recommendations for the clinical application of immunotherapy for prostate cancer patients. To do so, a systematic literature search was performed to identify high-impact papers from 2006 until 2014 and was further supplemented with literature provided by the panel. Results from the consensus panel voting and discussion as well as the literature review were used to rate supporting evidence and generate recommendations for the use of immunotherapy in prostate cancer patients. Sipuleucel-T, an autologous dendritic cell vaccine, is the first and currently only immunotherapeutic agent approved for the clinical management of metastatic castrate resistant prostate cancer (mCRPC). The consensus panel utilized this model to discuss immunotherapy in the treatment of prostate cancer, issues related to patient selection, monitoring of patients during and post treatment, and sequence/combination with other anti-cancer treatments. Potential immunotherapies emerging from late-stage clinical trials are also discussed. As immunotherapy evolves as a therapeutic option for the treatment of prostate cancer, these recommendations will be updated accordingly. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40425-016-0198-x) contains supplementary material, which is available to authorized users

    New phase transitions in ceramic SrSnO3: Raman scattering analysis and differential thermal analysis

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    We report a continuous or nearly continuous order-disorder transition from orthorhombic (pseudo-tetragonal) to orthorhombic structure on heating in SrSnO3 at 377 degrees C, and a discontinuous transition near 260 degrees C. The transition at 377 degrees C is manifested in an order of magnitude increase in Raman linewidths and in lambda-shaped anomaly in the specific heat. Previous work (Mountstevens et al 2005 Phys. Rev. B 71 220102R) has interpreted the Pnma-Imma transition at 636 degrees C as a continuous order-disorder transition and emphasized that this would be unique for an octahedron-tilting transition in oxide perovskite, as they have always been found to be displacive ('Glazer's rule'). Our work on Raman scattering and differential thermal analysis shows that the disorder sets in at much lower temperature 377 degrees C, so that the 636 degrees C transition is a disorder-disorder or a displacive transition within an already highly disordered structure. Hence it may not be as unusual as had been claimed, and Glazer's rule remains inviolate.X1110sciescopu

    Periodontal disease and type I diabetes mellitus: Associations with glycemic control and complications

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    Objective: The aim of the study was to evaluate periodontal health status in patients diagnosed with type 1 diabetes mellitus (DM1) and to establish a correlation between metabolic control and periodontal health status. Materials and Methods: Periodontal health parameters namely plaque index (PI), gingival index (GI), probing pocket depth (PPD) and clinical attachment loss (CAL) were recorded in 28 patients diagnosed with type 1 diabetes mellitus (DM1) and 20 healthy controls. Diabetes history was recorded based on the information provided by the physician and it included date of diagnosis, duration, age of diagnosis, latest values of glycosylated haemoglobin and existing diabetic complications. Statistical analysis was performed to evaluate the relationship between periodontal parameters and degree of metabolic control, the duration of the disease and the appearance of complications. Results: The periodontal health in the diabetic group was compromised and they had greater bleeding index (P < 0.001), probing pocket depth (P < 0.001) and clinical attachment level (P = 0.001). Patients diagnosed for diabetes for shorter duration of time (4-7 years) showed bleeding index-disease severity correlation to be 1.760 ΁ 0.434. Conclusion: Periodontal disease was more evident in type 1 diabetes mellitus patients and periodontal inflammation is greatly increased in subjects with longer disease course, poor metabolic control and diabetic complications

    New cryogenic phase transitions in SrSnO3

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    Strontium stannate is under study as an ultra-stable dielectric material for microelectronic applications at low temperatures. It is known to have a remarkably temperature-independent dielectric constant from 27 K to room temperature. However, we report anomalies in the Raman spectra, dielectric response, and differential thermal analysis of strontium stannate compatible with a structural phase transition at 160 K. Further anomalies are seen in calorimetric and Raman data (but not dielectric data) that suggest another phase transition at 270 K. A preliminary x-ray powder diffraction study confirms a small change in the pseudo-cubic lattice constant a(T) at the lower transition.X111415sciescopu
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