Effect of precursor on the performance of alumina for the dehydration of methanol to dimethyl ether

Dimethyl ether (DME) is amongst one of the most promising alternative, renewable and clean fuels being considered as a future energy carrier. In this study, the comparative catalytic performance of γ-Al2O3 prepared from two common precursors (aluminum nitrate (AN) and aluminum chloride (AC)) is presented. The impact of calcination temperature was evaluated in order to optimize both the precursor and pre-treatment conditions for the production of DME from methanol in a fixed bed reactor. The catalysts were characterized by TGA, XRD, BET and TPD-pyridine. Under reaction conditions where the temperature ranged from 180 °C to 300 °C with a WHSV = 12.1 h−1 it was found that all the catalysts prepared from AN(η-Al2O3) showed higher activity, at all calcination temperatures, than those prepared from AC(γ-Al2O3). In this study the optimum catalyst was produced from AN and calcined at 550 °C. This catalyst showed a high degree of stability and had double the activity of the commercial γ-Al2O3 or 87% of the activity of commercial ZSM-5(80) at 250 °C.

Clinical outcomes and inflammatory biomarkers in current smokers and exsmokers with severe asthma

Clinical outcomes are worse in current smokers and exsmokers with mild-to-moderate asthma compared with never smokers, but little is known about the influence of smoking status in patients with severe asthma.

Research in Progress: Medical Research Council United Kingdom Refractory Asthma Stratification Programme (RASP-UK)

The UK Refractory Asthma Stratification Programme(RASP-UK) will explore novel biomarker stratificationstrategies in severe asthma to improve clinicalmanagement and accelerate development of newtherapies. Prior asthma mechanistic studies have notstratified on inflammatory phenotype and theunderstanding of pathophysiological mechanisms inasthma without Type 2 cytokine inflammation is limited.RASP-UK will objectively assess adherence tocorticosteroids (CS) and examine a novel compositebiomarker strategy to optimise CS dose; this will alsoaddress what proportion of patients with severe asthmahave persistent symptoms without eosinophilic airwaysinflammation after progressive CS withdrawal. There will be interactive partnership with the pharmaceutical industry to facilitate access to stratified populations for novel therapeutic studies.

The cost of treating severe refractory asthma in the UK: an economic analysis from the British Thoracic Society Difficult Asthma Registry

Severe refractory asthma poses a substantial burden in terms of healthcare costs but relatively little is known about the factors which drive these costs. This study uses data from the British Thoracic Society Difficult Asthma Registry (n=596) to estimate direct healthcare treatment costs from an National Health Service perspective and examines factors that explain variations in costs. Annual mean treatment costs among severe refractory asthma patients were £2912 (SD £2212) to £4217 (SD £2449). Significant predictors of costs were FEV1% predicted, location of care, maintenance oral corticosteroid treatment and body mass index. Treating individuals with severe refractory asthma presents a substantial cost to the health service.

The TGF-β-inducible miR-23a cluster attenuates IFN-γ levels and antigen-specific cytotoxicity in human CD8+ T cells

Cytokine secretion and degranulation represent key components of CD8(+) T-cell cytotoxicity. While transcriptional blockade of IFN-γ and inhibition of degranulation by TGF-β are well established, we wondered whether TGF-β could also induce immune-regulatory miRNAs in human CD8(+) T cells. We used miRNA microarrays and high-throughput sequencing in combination with qRT-PCR and found that TGF-β promotes expression of the miR-23a cluster in human CD8(+) T cells. Likewise, TGF-β up-regulated expression of the cluster in CD8(+) T cells from wild-type mice, but not in cells from mice with tissue-specific expression of a dominant-negative TGF-β type II receptor. Reporter gene assays including site mutations confirmed that miR-23a specifically targets the 3'UTR of CD107a/LAMP1 mRNA, whereas the further miRNAs expressed in this cluster-namely, miR-27a and -24-target the 3'UTR of IFN-γ mRNA. Upon modulation of the miR-23a cluster by the respective miRNA antagomirs and mimics, we observed significant changes in IFN-γ expression, but only slight effects on CD107a/LAMP1 expression. Still, overexpression of the cluster attenuated the cytotoxic activity of antigen-specific CD8(+) T cells. These functional data thus reveal that the miR-23a cluster not only is induced by TGF-β, but also exerts a suppressive effect on CD8(+) T-cell effector functions, even in the absence of TGF-β signaling.

Comorbidity in severe asthma requiring systemic corticosteroid therapy: cross-sectional data from the Optimum Patient Care Research Database and the British Thoracic Difficult Asthma Registry

Objective: To determine the prevalence of systemic corticosteroid-induced morbidity in severe asthma.
Design: Cross-sectional observational study.Setting The primary care Optimum Patient Care Research Database and the British Thoracic Society Difficult Asthma Registry.
Participants: Optimum Patient Care Research Database (7195 subjects in three age- and gender-matched groups)—severe asthma (Global Initiative for Asthma (GINA) treatment step 5 with four or more prescriptions/year of oral corticosteroids, n=808), mild/moderate asthma (GINA treatment step 2/3, n=3975) and non-asthma controls (n=2412). 770 subjects with severe asthma from the British Thoracic Society Difficult Asthma Registry (442 receiving daily oral corticosteroids to maintain disease control).
Main outcome measures: Prevalence rates of morbidities associated with systemic steroid exposure were evaluated and reported separately for each group.
Results: 748/808 (93%) subjects with severe asthma had one or more condition linked to systemic corticosteroid exposure (mild/moderate asthma 3109/3975 (78%), non-asthma controls 1548/2412 (64%); p<0.001 for severe asthma versus non-asthma controls). Compared with mild/moderate asthma, morbidity rates for severe asthma were significantly higher for conditions associated with systemic steroid exposure (type II diabetes 10% vs 7%, OR=1.46 (95% CI 1.11 to 1.91), p<0.01; osteoporosis 16% vs 4%, OR=5.23, (95% CI 3.97 to 6.89), p<0.001; dyspeptic disorders (including gastric/duodenal ulceration) 65% vs 34%, OR=3.99, (95% CI 3.37 to 4.72), p<0.001; cataracts 9% vs 5%, OR=1.89, (95% CI 1.39 to 2.56), p<0.001). In the British Thoracic Society Difficult Asthma Registry similar prevalence rates were found, although, additionally, high rates of osteopenia (35%) and obstructive sleep apnoea (11%) were identified.

Conclusions: Oral corticosteroid-related adverse events are common in severe asthma. New treatments which reduce exposure to oral corticosteroids may reduce the prevalence of these conditions and this should be considered in cost-effectiveness analyses of these new treatments.

Dedicated severe asthma services improve health-care use and quality of life

Background: Systematic assessment of severe asthma can be used to confirm the diagnosis, identify comorbidities, and address adherence to therapy. However, the prospective usefulness of this approach is yet to be established. The objective of this study was to determine whether the systematic assessment of severe asthma is associated with improved quality of life (QoL) and health-care use and, using prospective data collection, to compare relevant outcomes in patients referred with severe asthma to specialist centers across the United Kingdom. Methods: Data from the National Registry for dedicated UK Difficult Asthma Services were used to compare patient demographics, disease characteristics, and health-care use between initial assessment and a median follow-up of 286 days. Results: The study population consisted of 346 patients with severe asthma. At follow-up, there were significant reductions in health-care use in terms of primary care or ED visits (66.4% vs 87.8%, P < .0001) and hospital admissions (38% vs 48%, P = .0004). Although no difference was noted in terms of those requiring maintenance oral corticosteroids, there was a reduction in steroid dose (10 mg [8-20 mg] vs 15 mg [10-20 mg], P = .003), and fewer subjects required short-burst steroids (77.4% vs 90.8%, P = .01). Significant improvements were seen in QoL and control using the Asthma Quality of Life Questionnaire and the Asthma Control Questionnaire. Conclusions: To our knowledge, this is the first time that a prospective study has shown that a systematic assessment at a dedicated severe asthma center is associated with improved QoL and asthma control and a reduction in health-care use and oral steroid burden.