P2Y₂ Nucleotide Receptors Expressed Heterologously in Sympathetic Neurons Inhibit Both N-Type Ca²⁺ and M-Type K⁺ Currents

The P2Y₂ receptor is a uridine/adenosine triphosphate (UTP/ATP)-sensitive G-protein-linked nucleotide receptor that previously has been reported to stimulate the phosphoinositide signaling pathway. Messenger RNA for this receptor has been detected in brain tissue. We have investigated the coupling of the molecularly defined rat P2Y₂ receptor to neuronal N-type Ca²⁺ channels and to M-type K⁺ channels by heterologous expression in rat superior cervical sympathetic (SCG) neurons. After the injection of P2Y₂cRNA, UTP inhibited the currents carried by both types of ion channel. As previously reported [Filippov AK, Webb TE, Barnard EA, Brown DA (1997) Inhibition by heterologously expressed P2Y₂nucleotide receptors of N-type calcium currents in rat sympathetic neurones. Br J Pharmacol 121:849–851], UTP inhibited the Ca²⁺ current (I_{Ca(N)} by up to 64%, with an IC₅₀ of ∼0.5 μm. We now find that UTP also inhibited the K⁺_{M} current (I_{K(M)} by up to 61%, with an IC₅₀ of ∼1.5 μm. UTP had no effect on either current in neurons not injected with P2Y₂ cRNA. Structure–activity relations for the inhibition of I_{Ca(N)} and I_{K(M)} in P2Y₂ cRNA-injected neurons were similar, with UTP ≥ ATP > ITP ≫ GTP,UDP. However, coupling to these two channels involved different G-proteins: pretreatment withPertussis toxin (PTX) did not affect UTP-induced inhibition of I_{K(M)} but reduced inhibition of I_{Ca(N)} by ∼60% and abolished the voltage-dependent component of this inhibition. In unclamped neurons, UTP greatly facilitated depolarization-induced action potential discharges. Thus, the single P2Y₂ receptor can couple to at least two G-proteins to inhibit both Ca²⁺_{N} and K⁺_{M} channels with near-equal facility. This implies that the P2Y₂ receptor may induce a broad range of effector responses in the nervous system

Prospective mental imagery as its link with anxiety and depression in prisoners

Mental imagery is known to play a key role in the development and maintenance of depression and anxiety. Prisoners commonly experience psychological distress, but interventions to address this are currently lacking. We aimed to examine the link between prospective mental imagery and anxiety and depression among prisoners. One hundred twenty-three male prisoners from a Category C prison in southwest England participated in the study. They completed the Centre for Epidemiologic Studies Depression Scale (CES-D) and the General Anxiety Disorder Scale (GAD-7) to measure whether they experience depression and/or anxiety symptoms. Furthermore, they completed additional questionnaires to evaluate their prospective mental imagery. Results showed that 67.5% of prisoners presented with more depression symptoms and 27.7% with more anxiety symptoms. Supporting earlier findings, our data revealed that some dimensions of prospective mental imagery were significantly related with increased anxiety and depression symptoms in prisoners. Namely, intrusive negative personally relevant imagery was a positive predictor and likelihood of positive events a negative predictor of both anxiety and depression symptoms. The perceived likelihood of negative events was a positive predictor of depression. Intrusive verbal thought was a positive predictor of anxiety. The obtained results suggest the need to develop interventions not only targeting the reduction of prospective negative imagery but also the enhancement of positive mental imagery

Heparan sulfate phage display antibodies recognise epitopes defined by a combination of sugar sequence and cation binding.

Phage display antibodies are widely used to follow heparan sulfate (HS) expression in tissues and cells. We demonstrate by ELISA, that cations alter phage display antibody binding profiles to HS and this is mediated by changes in polysaccharide conformation, demonstrated by circular dichroism spectroscopy. Native HS structures, expressed on the cell surfaces of neuroblastoma and fibroblast cells, also exhibited altered antibody binding profiles following exposure to low mM concentrations of these cations. Phage display antibodies recognise conformationally-defined HS epitopes, rather than sequence alone, as has been assumed, and resemble proteins in being sensitive to changes in both charge distribution and conformation following binding of cations to HS polysaccharides

Cost-effectiveness of noninvasive liver fibrosis tests for treatment decisions in patients with chronic hepatitis C

The cost-effectiveness of noninvasive tests (NITs) as alternatives to liver biopsy is unknown. We compared the cost-effectiveness of using NITs to inform treatment decisions in adult patients with chronic hepatitis C (CHC). We conducted a systematic review and meta-analysis to calculate the diagnostic accuracy of various NITs using a bivariate random-effects model. We constructed a probabilistic decision analytical model to estimate health care costs and outcomes (quality-adjusted life-years; QALYs) using data from the meta-analysis, literature, and national UK data. We compared the cost-effectiveness of four treatment strategies: testing with NITs and treating patients with fibrosis stage ≥F2; testing with liver biopsy and treating patients with ≥F2; treat none; and treat all irrespective of fibrosis. We compared all NITs and tested the cost-effectiveness using current triple therapy with boceprevir or telaprevir, but also modeled new, more-potent antivirals. Treating all patients without any previous NIT was the most effective strategy and had an incremental cost-effectiveness ratio (ICER) of £9,204 per additional QALY gained. The exploratory analysis of currently licensed sofosbuvir treatment regimens found that treat all was cost-effective, compared to using an NIT to decide on treatment, with an ICER of £16,028 per QALY gained. The exploratory analysis to assess the possible effect on results of new treatments, found that if SVR rates increased to >90% for genotypes 1-4, the incremental treatment cost threshold for the "treat all" strategy to remain the most cost-effective strategy would be £37,500. Above this threshold, the most cost-effective option would be noninvasive testing with magnetic resonance elastography (ICER=£9,189). Conclusions: Treating all adult patients with CHC, irrespective of fibrosis stage, is the most cost-effective strategy with currently available drugs in developed countries. © 2014 The Authors

Development and validation of a mathematical equation to estimate glomerular filtration rate in cirrhosis: The rfh cirrhosis Gfr

Current expressions based on serum creatinine concentration overestimate kidney function in cirrhosis leading to significant differences between "true" and calculated glomerular filtration rate (GFR). We compared the performance of MDRD-4, MDRD-6 and CKD-EPI with "true" GFR and the impact of this difference on MELD calculation. We subsequently developed and validated a GFR equation specifically for cirrhosis and compared the performance of the new derived formula with existing GFR formulas. We included 469 consecutive patients who had a transplant assessment between 2011 and 2014. "True" GFR (mGFR) was measured using plasma isotope clearance according to a technique validated in patients with ascites. A corrected creatinine was derived from the mGFR after application of the MDRD formula. Subsequently, a corrected MELD was calculated and was compared with the conventionally calculated MELD. Stepwise multiple linear regression was used to derive a GFR equation. This was compared with the measured GFR in independent external and internal validation sets of 82 and 174 patients with cirrhosis respectively. A difference>20 ml/min/1.73m(2) between existing formulae and mGFR was observed in 226 (48.2%) patients. The corrected MELD score was ≥3 points higher in 177 (37.7%) patients. The predicted equation derived (R(2) =74·6%) was: GFR=45·9x(creatinine(-0) ·(836) )x(urea(-0) ·(229) )x(INR(-0) ·(113) )x(age(0) ·(129) )x(sodium(0) ·(972) )x1·236(if male)x0·92(if moderate/severe ascites). The model was a good fit and showed the greatest accuracy compared to that of existing formulae. CONCLUSION: We developed and validated a new accurate model for GFR assessment in cirrhosis, the RFH cirrhosis GFR, using readily available variables. This remains to be tested and incorporated in prognostic scores in patients with cirrhosis

Bacterial Infections Change Natural History of Cirrhosis Irrespective of Liver Disease Severity

OBJECTIVES: We assessed the prognostic significance of infections in relation to current prognostic scores and explored if infection could be considered per se a distinct clinical stage in the natural history of cirrhosis. METHODS: We included consecutive patients with cirrhosis admitted to a tertiary referral liver unit for at least 48 h over a 2-year period. Diagnosis of infection was based on positive cultures or strict established criteria. We used competing risk analysis and propensity score matching for data analysis. RESULTS: 501 patients (63% male, 48% alcoholic liver disease, median Model of End-stage Liver Disease (MELD)=17) underwent 781 admissions over the study period. Portal hypertensive bleeding and complicated ascites were the commonest reasons of admission. The incidence of proven bacterial infection was 25.6% (60% community acquired and 40% nosocomial). Survival rates at 3, 6, 12, and 30 months were 83%, 77%, 71%, and 62% in patients without diagnosis of infection, vs. 50%, 46%, 41%, and 34% in patients with diagnosis of infection. Overall survival was independently associated with MELD score (hazards ratio (HR) 1.099), intensive care (ITU) stay (HR 1.967) and bacterial infection (HR 2.226). Bacterial infection was an independent predictor of survival even when patients who died within the first 30 days were excluded from the analysis in Cox regression (HR 2.013) and competing risk Cox models in all patients (HR 1.46) and propensity risk score-matched infected and non-infected patients (HR 1.67). CONCLUSIONS: Infection most likely represents a distinct prognostic stage of cirrhosis, which affects survival irrespective of disease severity, even after recovery from the infective episode

Air Pollution in Bangalore, India: A Six-Year Trend and Health Implication Analysis

Air pollution is increasingly becoming a global concern and is believed to be amongst the leading causes of death in the world today. Developing countries, with rapidly growing economies, are struggling between the focus on economic development and curbing air pollution emissions. Bangalore is one of India’s fastest growing metropolises and, although benefiting economically due to its rapid development, has a rapidly deteriorating environment. This paper provides a critical analysis of the air pollution trend in the city over the period 2005-2011 at 6 specific locations where measurements have been consistently recorded. It also discusses the potential health implications pertaining to exceeding levels of pollutants where these are applicable

Spatial Interpolation of Air Pollutants in Bangalore: 2010-2013

Air pollutants and their ill effects on the environment and health of populations are well known. However for informed decisions on the protection of the health of populations from elevated levels of air pollution, an understanding of spatial-temporal variance of air pollutant patterns is necessary. Bangalore and other similar developing cities do not have an adequate number of fixed monitoring stations that could provide a complete coverage of the air pollution levels for the entire city. This can be overcome by using geospatial interpolation techniques that provide a complete coverage of the levels of pollutants. The aim of this study is to locate sample points, characterise distribution patterns, map air pollutant distributions using interpolation techniques, highlight areas exceeding standard levels and in doing so determine spatial and temporal patterns of the levels of air pollutants. An air pollution map indicating levels of the variability of the pollutants will aid in the analysis of effects on health in populations due to elevated levels of pollutants

Cost-effectiveness of noninvasive liver fibrosis tests for treatment decisions in patients with chronic hepatitis B in the UK: systematic review and economic evaluation

The copyright line for this article was changed on 18 November 2016 after original online publication. Abbreviations: CEAF cost-effectiveness frontier. CHB chronic hepatitis B. CI confidence intervals. FN false negative. FP false positive. HBV hepatitis B virus. HCC hepatocellular carcinoma. ICER incremental cost-effectiveness ratio. NITs noninvasive tests. QUADAS Quality Assessment of Diagnostic Accuracy Studies. QUALYs quality-adjusted-life-years. TN true negative. TP true positive.Copyright © 2015 The Authors. We compared the cost-effectiveness of various noninvasive tests (NITs) in patients with chronic hepatitis B and elevated transaminases and/or viral load who would normally undergo liver biopsy to inform treatment decisions. We searched various databases until April 2012. We conducted a systematic review and meta-analysis to calculate the diagnostic accuracy of various NITs using a bivariate random-effects model. We constructed a probabilistic decision analytical model to estimate health care costs and outcomes quality-adjusted-life-years (QALYs) using data from the meta-analysis, literature, and national UK data. We compared the cost-effectiveness of four decision-making strategies: testing with NITs and treating patients with fibrosis stage ≥F2, testing with liver biopsy and treating patients with ≥F2, treat none (watchful waiting) and treat all irrespective of fibrosis. Treating all patients without prior fibrosis assessment had an incremental cost-effectiveness ratio (ICER) of £28 137 per additional QALY gained for HBeAg-negative patients. For HBeAg-positive patients, using Fibroscan was the most cost-effective option with an ICER of £23 345. The base case results remained robust in the majority of sensitivity analyses, but were sensitive to changes in the ≥F2 prevalence and the benefit of treatment in patients with F0–F1. For HBeAg-negative patients, strategies excluding NITs were the most cost-effective: treating all patients regardless of fibrosis level if the high cost-effectiveness threshold of £30 000 is accepted; watchful waiting if not. For HBeAg-positive patients, using Fibroscan to identify and treat those with ≥F2 was the most cost-effective option.The analysis for Hepatitis B was part of a larger project funded by The National Institute for Health Research Health Technology Assessment (HTA project 09/114/02) and will be published in full in the Health Technology Assessment journal series. Visit the HTA programme website for more details www.hta.ac.uk/link to project page