Acrolein decreases endothelial cell migration and insulin sensitivity through induction of let-7a

Acrolein is a major reactive component of vehicle exhaust, and cigarette and wood smoke. It is also present in several food substances and is generated endogenously during inflammation and lipid peroxidation. Although previous studies have shown that dietary or inhalation exposure to acrolein results in endothelial activation, platelet activation, and accelerated atherogenesis, the basis for these effects is unknown. Moreover, the effects of acrolein on microRNA (miRNA) have not been studied. Using AGILENT miRNA microarray high-throughput technology, we found that treatment of cultured human umbilical vein endothelial cells with acrolein led to a significant (>1.5-fold) upregulation of 12, and downregulation of 15, miRNAs. Among the miRNAs upregulated were members of the let-7 family and this upregulation was associated with decreased expression of their protein targets, β3 integrin, Cdc34, and K-Ras. Exposure to acrolein attenuated β3 integrin-dependent migration and reduced Akt phosphorylation in response to insulin. These effects of acrolein on endothelial cell migration and insulin signaling were reversed by expression of a let-7a inhibitor. Also, inhalation exposure of mice to acrolein (1 ppm x 6 h/day x 4 days) upregulated let-7a and led to a decrease in insulin-stimulated Akt phosphorylation in the aorta. These results suggest that acrolein exposure has broad effects on endothelial miRNA repertoire and that attenuation of endothelial cell migration and insulin signaling by acrolein is mediated in part by the upregulation of let-7a. This mechanism may be a significant feature of vascular injury caused by inflammation, oxidized lipids, and exposure to environmental pollutants.

Quality of HIV care in the United Kingdom: key indicators for the first 12 months from HIV diagnosis

OBJECTIVES

Prompt HIV diagnosis and treatment are associated with increased longevity and reduced transmission. The aim of the study was to examine late diagnoses and to assess the quality of care following diagnosis.

METHODS

National surveillance and cohort data were used to examine late HIV diagnoses and to assess the quality of care received in the 12 months following HIV diagnosis.

RESULTS

In 2011, 79% (4910/6219) of persons (15 years and over) diagnosed with HIV infection had CD4 counts reported within 3 months; of these, 49% were diagnosed late (CD4 count < 350 cells/μL). Adults aged 50 years and over were more likely to be diagnosed late (67%) compared with those aged 15-24 years (31%). Sixty-four per cent of heterosexual men were diagnosed late compared with 46% of women and 36% of men who have sex with men (MSM) (P < 0.01). The percentage of late diagnoses was highest among black African adults (66%) compared with other ethnicities; 96% of black African adults diagnosed late were born abroad. Overall, 88% and 97% of patients were linked to care within 1 and 3 months of diagnosis, respectively, with little variation by demographics and exposure category. The crude 1-year mortality rate was 31.6 per 1000 persons diagnosed in 2010. It was highest among adults diagnosed late (40.3/1000 versus 5.2/1000 for prompt diagnoses) and particularly among those aged 50 years and over. Excluding deaths, 85% of the 5833 diagnosed in 2010 were retained in care in 2011; 92% of the 2264 adults diagnosed late in 2010 received antiretroviral therapy by the end of 2011.

CONCLUSIONS

The National Health Service provides high-quality care to persons newly diagnosed with HIV infection in the UK, with no evidence of health inequalities. Despite excellent care, half of adults are diagnosed late according to the threshold at which national guidelines recommend treatment should begin. Such patients have an 8-fold increased risk of 1-year mortality compared with those diagnosed promptly. Reducing late diagnosis of HIV infection remains a public health priority in the UK.

Classical-NOVA CONTRIBUTION to the Milky Way's ²⁶Al abundance: exit channel of the key ²⁵Al(p,γ) ²⁶Si resonance

Classical novae are expected to contribute to the 1809-keV Galactic γ-ray emission by producing its precursor 26Al, but the yield depends on the thermonuclear rate of the unmeasured 25Al(p,γ)26Si reaction. Using the β decay of 26P to populate the key J(π)=3(+) resonance in this reaction, we report the first evidence for the observation of its exit channel via a 1741.6±0.6(stat)±0.3(syst)  keV primary γ ray, where the uncertainties are statistical and systematic, respectively. By combining the measured γ-ray energy and intensity with other experimental data on 26Si, we find the center-of-mass energy and strength of the resonance to be E(r)=414.9±0.6(stat)±0.3(syst)±0.6(lit.)  keV and ωγ=23±6(stat)(-10)(+11)(lit.)  meV, respectively, where the last uncertainties are from adopted literature data. We use hydrodynamic nova simulations to model 26Al production showing that these measurements effectively eliminate the dominant experimental nuclear-physics uncertainty and we estimate that novae may contribute up to 30% of the Galactic 26Al.

Gene expression profiles in engineered cardiac tissues respond to mechanical loading and inhibition of tyrosine kinases

Engineered cardiac tissues (ECTs) are platforms to investigate cardiomyocyte maturation and functional integration, the feasibility of generating tissues for cardiac repair, and as models for pharmacology and toxicology bioassays. ECTs rapidly mature in vitro to acquire the features of functional cardiac muscle and respond to mechanical load with increased proliferation and maturation. ECTs are now being investigated as platforms for in vitro models for human diseases and for pharmacologic screening for drug toxicities. We tested the hypothesis that global ECT gene expression patterns are complex and sensitive to mechanical loading and tyrosine kinase inhibitors similar to the maturing myocardium. We generated ECTs from day 14.5 rat embryo ventricular cells, as previously published, and then conditioned constructs after 5 days in culture for 48 h with mechanical stretch (5%, 0.5 Hz) and/or the p38 MAPK (p38 mitogen-activated protein kinase) inhibitor BIRB796. RNA was isolated from individual ECTs and assayed using a standard Agilent rat 4 × 44k V3 microarray and Pathway Analysis software for transcript expression fold changes and changes in regulatory molecules and networks. Changes in expression were confirmed by quantitative-polymerase chain reaction (q-PCR) for selected regulatory molecules. At the threshold of a 1.5-fold change in expression, stretch altered 1559 transcripts, versus 1411 for BIRB796, and 1846 for stretch plus BIRB796. As anticipated, top pathways altered in response to these stimuli include cellular development, cellular growth and proliferation; tissue development; cell death, cell signaling, and small molecule biochemistry as well as numerous other pathways. Thus, ECTs display a broad spectrum of altered gene expression in response to mechanical load and/or tyrosine kinase inhibition, reflecting a complex regulation of proliferation, differentiation, and architectural alignment of cardiomyocytes and noncardiomyocytes within ECT.

Comparison of nonlinear mammalian cochlear-partition models

Various simple mathematical models of the dynamics of the organ of Corti in the mammalian cochlea are analyzed and their dynamics compared. The specific models considered are phenomenological Hopf and cusp normal forms, a recently proposed description combining active hair-bundle motility and somatic motility, a reduction thereof, and finally a model highlighting the importance of the coupling between the nonlinear transduction current and somatic motility. It is found that for certain models precise tuning to any bifurcation is not necessary and that a compressively nonlinear response over a range similar to experimental observations and that the normal form of the Hopf bifurcation is not the only description that reproduces compression and tuning similar to experiment.

Electromagnetic transition rates in 100,101Pd using the Recoil Doppler Shift Technique

The quadrupole deformations for the low-lying states in the transitional nuclei 100,101Pd have been deduced through the measurement of their electric quadrupole transition probabilities using the Recoil Distance Doppler Shift Method. The nuclei were studied using a 268 MeV 80Se beam impinging on a thin, self-supporting 24Mg target. States in 100Pd and 101Pd populated by the four and three neutron evaporation channels respectively, with reaction gamma-rays detected using the SPEEDY gamma-ray detection array. The recoiling nuclei were stopped in a copper foil and gamma-ray coincidence data taken at 10 separate target-stopper distances between 35 μm and 750 μm. The mean-lifetimes for the lowest lying 2+ (in 100Pd) and 15/2- (in 101Pd) states were measured to be 13.3(9) ps and 10.8(8) ps respectively. These data are compared with predictions from nuclear Total Routhian Surface calculations, which are found to agree with the experimentally deduced values to within 10%.

What is the clinical effectiveness and cost-effectiveness of using drugs in treating obese patients in primary care? A systematic review

BACKGROUND

Obesity [defined as a body mass index (BMI) ≥ 30 kg/m(2)] represents a considerable public health problem and is associated with a significant range of comorbidities and an increased mortality risk. The primary aim of the management of obesity is to achieve weight reduction in the interests of health. For obese patients who cannot achieve or maintain a healthy weight by non-pharmacological means, drug therapy is recommended in combination with non-pharmacological interventions such as dietary modifications and exercise.

OBJECTIVE

To evaluate the clinical effectiveness and cost-effectiveness of three pharmacological interventions in obese patients.

DATA SOURCES

Clinical effectiveness data used in the meta-analysis were sourced from articles identified in a systematic review of the literature. Data used to inform transitions to obesity-related comorbidities were derived from the General Practice Research Database (GPRD). The results of the meta-analysis and GPRD analyses informed the economic model supplemented by data from the Health Survey for England and other UK-specific data sourced from the literature.

REVIEW METHODS

A systematic literature review was conducted of the clinical effectiveness and cost-effectiveness of orlistat, sibutramine and rimonabant within their licensed indications for the treatment of obese patients. Electronic bibliographic databases including MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library databases and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched in January 2009, and the reference lists of relevant articles were checked. Studies were included if they compared orlistat, sibutramine or rimonabant with lifestyle and/or exercise advice (standard care), placebo or metformin.

RESULTS

Overall, 94 studies involving 24,808 individuals were included in the clinical meta-analysis. Eighty-three trials included data on weight change, 41 included data on BMI change and 45 and 36 studies reported on 5% and 10% body weight loss, respectively. Overall, the results show that the active drug interventions are all effective at reducing weight and BMI compared with placebo. In the case of sibutramine, the higher dose (15 mg) resulted in a greater reduction than the lower dose (10 mg). Generally, the data quality of the trials included was low with poor reporting of standard errors and standard deviations. Results from the BMI risk models derived from the GPRD showed consistent increases in risk with increasing BMI. Adjustments for key confounders, such as age, sex and smoking status, were found to be statistically significant at the 5% level, in all risk models. Applying linear models to estimate BMI trajectories, for the diabetic cohort, an average increase in BMI of 0.040 per year for both men and women was observed. The non-diabetic cohort model showed an increase in BMI of 0.175 per year for women and 0.145 per year for men. The results of the cost-effectiveness analyses suggest that sibutramine 15 mg dominates the other three active interventions and the net benefit analyses show that sibutramine 15 mg is the most cost-effective alternative for thresholds > £2000 per quality-adjusted life-year (QALY). However, both sibutramine and rimonabant have been withdrawn because of safety concerns relating to potential treatment-induced fatal adverse events. If the proportion of patients who experienced a fatal adverse event was > 1.8% (1.5%, 1.0%) for sibutramine 15 mg (sibutramine 10 mg, rimonabant) the treatment would not be considered cost-effective when using a threshold of £20,000 per QALY.

LIMITATIONS

The clinical review did not include all possible lifestyle comparators, with the inclusion limited to only those trials included one of the active drug interventions. We also excluded all studies not reported in English. Although the clinical review included data from 94 studies, the quality of data was generally low, particularly in terms of the reporting of standard deviation. There was also inconsistency between the results of the mixed-treatment comparison (MTC) and the pair-wise analyses.

CONCLUSION

The MTC of anti-obesity treatments shows that all the active treatments are effective at reducing weight and BMI. The economic results show that, compared with placebo, the treatments are all cost-effective when using a threshold of £20,000 per QALY, and, within the limitations of the data available, sibutramine 15 mg dominates the other three interventions. This work has highlighted many areas of methodological research that could be explored, including assessing inconsistencies within a network to determine differences between the results of pair-wise and MTC analyses; the use of meta-regression methods to look for effect modifiers; exploring the effect of local publication bias; and the use of joint models to analyse the repeated measures of BMI and the time-to-event processes simultaneously.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

A systematic review and mixed treatment comparison of pharmacological interventions for the treatment of obesity

The study aims to compare anti-obesity interventions in a single evidence synthesis framework. Electronic databases were searched for randomized controlled trials of orlistat, rimonabant or sibutramine reporting weight or body mass index (BMI) change from baseline at 3, 6 or 12 months. A mixed treatment comparison was used to combine direct and indirect trial evidence. Ninety-four studies involving 24,808 individuals were included; 83 trials included data on weight change and 41 on BMI change. All results are in comparison with placebo. The active drugs were all effective at reducing weight and BMI. At 3 months, orlistat reduced weight by -2.65 kg (95% credibility interval -4.00 kg, -1.31 kg). For sibutramine, 15 mg gave a greater reduction than 10 mg at 12 months, -6.35 kg versus -5.42 kg, respectively. Rimonabant reduced weight by -11.23 kg at 3 months and -4.55 kg at 12 months. Lifestyle advice alone also reduced weight at 6 and 12 months, but was less effective than the pharmacological interventions. In conclusion, modest weight reductions were seen for all pharmacological interventions. Those interventions which have now been withdrawn from use (sibutramine and rimonabant) seem to be the most effective, implying that there may be a place in clinical practice for similar drugs if side effects could be avoided.

Conditioned taste aversion dependent regulation of amygdala gene expression

The present experiments investigated gene expression in the amygdala following contingent taste/LiCl treatment that supports development of conditioned taste aversion (CTA). The use of whole genome chips and stringent data set filtering led to the identification of 168 genes regulated by CTA compared to non-contingent LiCl treatment that does not support CTA learning. Seventy-six of these genes were eligible for network analysis. Such analysis identified "behavior" as the top biological function, which was represented by 15 of the 76 genes. These genes included several neuropeptides, G protein-coupled receptors, ion channels, kinases, and phosphatases. Subsequent qRT-PCR analyses confirmed changes in mRNA expression for 5 of 7 selected genes. We were able to demonstrate directionally consistent changes in protein level for 3 of these genes; insulin 1, oxytocin, and major histocompatibility complex class I-C. Behavioral analyses demonstrated that blockade of central insulin receptors produced a weaker CTA that was less resistant to extinction. Together, these results support the notion that we have identified downstream genes in the amygdala that contribute to CTA learning.

KIR2DS1 genotype predicts for complete cytogenetic response and survival in newly diagnosed chronic myeloid leukemia patients treated with imatinib

Natural killer (NK) cells are expanded in chronic myeloid leukemia (CML) patients on tyrosine kinase inhibitors (TKI) and exert cytotoxicity. The inherited repertoire of killer immunoglobulin-like receptors (KIR) may influence response to TKI. We investigated the impact of KIR-genotype on outcome in 166 chronic phase CML patients on first-line imatinib treatment. We validated our findings in an independent patient group. On multivariate analysis, KIR2DS1 genotype (RR=1.51, P=0.03) and Sokal risk score (low-risk RR=1, intermediate-risk RR=1.53, P=0.04, high-risk RR=1.69, P=0.034) were the only independent predictors for failure to achieve complete cytogenetic response (CCyR). Furthermore, KIR2DS1 was the only factor predicting shorter progression-free (PFS) (RR=3.1, P=0.03) and overall survival (OS) (RR=2.6, P=0.04). The association between KIR2DS1 and CCyR, PFS and OS was validated by KIR genotyping in 174 CML patients on first-line imatinib in the UK multi-center SPIRIT-1 trial; in this cohort, KIR2DS1(+) patients had significantly lower 2-year probabilities of achieving CCyR (76.9 vs 87.9%, P=0.003), PFS (85.3 vs 98.1%, P=0.007) and OS (94.4 vs 100%, P=0.015) than KIR2DS1(-) patients. The impact of KIR2DS1 on CCyR was greatest when the ligand for the corresponding inhibitory receptor, KIR2DL1, was absent (P=0.00006). Our data suggest a novel role for KIR-HLA immunogenetics in CML patients on TKI.

What factors shape rates of phenotypic evolution? A comparative study of cranial morphology of four mammalian clades

Understanding why rates of morphological evolution vary is a major goal in evolutionary biology. Classical work suggests that body size, interspecific competition, geographic range size and specialization may all be important, and each may increase or decrease rates of evolution. Here, we investigate correlates of proportional evolutionary rates in phalangeriform possums, phyllostomid bats, platyrrhine monkeys and marmotine squirrels, using phylogenetic comparative methods. We find that the most important correlate is body size. Large species evolve the fastest in all four clades, and there is a nonlinear relationship in platyrrhines and phalangeriformes, with the slowest evolution in species of intermediate size. We also find significant increases in rate with high environmental temperature in phyllostomids, and low mass-specific metabolic rate in marmotine squirrels. The mechanisms underlying these correlations are uncertain and appear to be size specific. We conclude that there is significant variation in rates of evolution, but that its meaning is not yet clear.

Etanercept, infliximab and adalimumab for the treatment of psoriatic arthritis: a systematic review and economic evaluation

BACKGROUND

Etanercept, infliximab and adalimumab are licensed in the UK for the treatment of active and progressive psoriatic arthritis (PsA) in adults who have an inadequate response to standard treatment.

OBJECTIVE

To determine the clinical effectiveness, safety and cost-effectiveness of these biologic agents in the treatment of active and progressive PsA.

DATA SOURCES

Systematic reviews were performed, with data sought from 10 electronic databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Science Citation Index, Conference Proceedings Citation Index - Science, ClinicalTrials.gov, metaRegister of Current Controlled Trials, NHS Economic Evaluation Database, Health Economic Evaluations Database and EconLit) up to June 2009.

REVIEW METHODS

Full paper manuscripts of titles/abstracts considered relevant were obtained and assessed for inclusion by two reviewers according to criteria on study design, interventions, participants and outcomes. Data on study and participant characteristics, efficacy outcomes, adverse effects, costs to the health service and cost-effectiveness were extracted, along with baseline data where reported. The primary efficacy outcomes were measures of anti-inflammatory response, skin lesion response and functional status, and the safety outcome was the incidence of serious adverse events. The primary measure of cost-effectiveness was incremental cost per additional quality-adjusted life-year (QALY). Standard meta-analytic techniques were applied to efficacy data. Published cost-effectiveness studies and the economic analyses submitted to the National Institute for Health and Clinical Excellence (NICE) by the biologic manufacturers were reviewed. An economic model was developed by updating the model produced by the York Assessment Group for the previous NICE appraisal of biologics in PsA.

RESULTS

Pooled estimates of effect demonstrated a significant improvement in patients with PsA for all joint disease and functional status outcomes at 12-14 weeks' follow-up. The biologic treatment significantly reduced joint symptoms for etanercept [relative risk (RR) 2.60, 95% confidence interval (CI) 1.96 to 3.45], infliximab (RR 3.44, 95% CI 2.53 to 4.69) and adalimumab (RR 2.24, 95% CI 1.74 to 2.88), with 24-week data demonstrating maintained treatment effects. Trial data demonstrated a significant effect of all three biologics on skin disease at 12 or 24 weeks. Evidence synthesis found that infliximab appeared to be most effective across all outcomes of joint and skin disease. The response in joint disease was greater with etanercept than with adalimumab, whereas the response in skin disease was greater with adalimumab than with etanercept, although these differences are not statistically significant. Under base-case assumptions, etanercept was the most likely cost-effective strategy for patients with PsA and mild-to-moderate psoriasis if the threshold for cost-effectiveness was £20,000 or £30,000 per QALY. All biologics had a similar probability of being cost-effective for patients with PsA and moderate-to-severe psoriasis at a threshold of £20,000 per QALY.

LIMITATIONS

Limited available efficacy data and difficulty in assessing PsA activity and its response to biologic therapy.

CONCLUSIONS

The data indicated that etanercept, infliximab and adalimumab were efficacious in the treatment of PsA compared with placebo, with beneficial effects on joint symptoms, functional status and skin. Short-term data suggested that these biologic agents can delay joint disease progression and evidence to support their use in the treatment of PsA is convincing. Future research would benefit from long-term observational studies with large sample sizes of patients with PsA to demonstrate that beneficial effects are maintained, along with further monitoring of the safety profiles of the biologic agents.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

A review of the clinical and legal issues surrounding refusal of treatment following overdose

This article reviews the clinical and legal issues involved in dealing with patients who refuse medical treatment following an overdose. We first describe a real case that has been made anonymous, before discussing a general approach to management. We then review the relevant legislation, including the Mental Capacity Act (2005), the Mental Health Act (1983) and legal issues surrounding the treatment of young people. We discuss how this legislation may be applied in practice and then conclude with the outcome of the case, sources of further information and some key learning points.