Dimethyl ether (DME) is a promising substitute for diesel as a fuel in heavy-duty engines. This article presents the comparison between a diesel- and a DME-powered compression ignition engine. The diesel-powered version was initially characterised at a range of operating points before being converted to operate on DME. This was achieved by replacing fuel system components with bespoke DME-compatible engine parts. An off-board fuel pressurisation and conditioning system was designed to replace the existing high-pressure fuel pump, while maintaining all other engine hardware and components. Engine behaviour, in terms of combustion and emissions on both fuels was examined. Firstly, the effect of varying recirculated exhaust gas (EGR) concentration at constant excess air ratio, combustion phasing (CA50) and equal fuel delivery rate (by energy input) was interrogated. DME combustion was significantly faster, as combustion duration was reduced by around 30%, in some cases, when comparing to diesel. The DME-powered version of the engine was also found to produce lower carbon monoxide (CO) and unburned hydrocarbon (uHC) emissions. Up to a threefold reduction was measured, depending on engine load. NOx emissions worsened, when transitioning to DME, for the medium load case. The low-load EGR sweep showed minimal changes in NOx emissions. High-pressure EGR can significantly lower DME NOx emissions to below the diesel baseline levels, depending on engine load and speed, as demonstrated by the results of the 8-mode test runs. Given the extremely low particulate emissions, higher EGR concentrations can be utilised by engines operating on DME. Despite resorting to the use of bespoke equipment in this study, the challenges faced during the engine conversion were deemed manageable with the currently available technology.

Flame temperature and soot concentration imaging was performed using endoscopic two-colour (2C) soot pyrometry to investigate the characteristics of in-cylinder diesel engine combustion processes and provide validation data for engine simulation and design. To appropriately interpret the 2C image results, this paper focuses on the uncertainty and challenges of the technique, the line-of-sight nature of the measurement and presents comparable information for validation exercises. A line-of-sight flame light intensity model was created to explore how the temperature T and soot concentration KL measured by the 2C technique can relate to non-uniform flame temperature and soot distributions. It was found that T and KL measured from the 2C technique were likely to relate differently to the actual distribution depending on where in the flame the measurement was taken and on assumptions made about the flame spatial structure. Assessment has been made of the range of the maximum and minimum flame temperatures (assumed to correspond to reaction zone temperature and flame centreline respectively) that are consistent with measured temperature T and soot concentration KL. The analysis of uncertainties, flame temperature and soot distribution along the line-of-sight, and image averaging allows for better quantitative comparison of 2C soot pyrometry images to CFD simulation, which increases confidence in simulation-driven engine development.

Pharmacological induction of fetal hemoglobin (HbF) expression is an effective therapeutic strategy for the management of beta-hemoglobinopathies such as sickle cell disease. DNA methyltransferase (DNMT) inhibitors 5-azacytidine (5-aza) and 5-aza-2′-deoxycytidine (decitabine) have been shown to induce fetal hemoglobin expression in both preclinical models and clinical studies, but are not currently approved for the management of hemoglobinopathies. We report here the discovery of a novel class of orally bioavailable DNMT1-selective inhibitors as exemplified by GSK3482364. This molecule potently inhibits the methyltransferase activity of DNMT1, but not DNMT family members DNMT3A or DNMT3B. In contrast with cytidine analog DNMT inhibitors, the DNMT1 inhibitory mechanism of GSK3482364 does not require DNA incorporation and is reversible. In cultured human erythroid progenitor cells (EPCs), GSK3482364 decreased overall DNA methylation resulting in de-repression of the gamma globin genes HBG1 and HBG2 and increased HbF expression. In a transgenic mouse model of sickle cell disease, orally administered GSK3482364 caused significant increases in both HbF levels and in the percentage HbF-expressing erythrocytes, with good overall tolerability. We conclude that in these preclinical models, selective, reversible inhibition of DNMT1 is sufficient for the induction of HbF, and is well-tolerated. We anticipate that GSK3482364 will be a useful tool molecule for the further study of selective DNMT1 inhibition both in vitro and in vivo.

The aim of this study is to investigate aerosol plume geometries of pressurised metered dose inhalers (pMDIs) using a high-speed laser image system with different actuator nozzle materials and designs. Actuators made from aluminium, PET and PTFE were manufactured with four different nozzle designs: cone, flat, curved cone and curved flat. Plume angles and spans generated using the designed actuator nozzles with four solution-based pMDI formulations were imaged using Oxford Lasers EnVision system and analysed using EnVision Patternate software. Reduced plume angles for all actuator materials and nozzle designs were observed with pMDI formulations containing drug with high co-solvent concentration (ethanol) due to the reduced vapour pressure. Significantly higher plume angles were observed with the PTFE flat nozzle across all formulations, which could be a result of the nozzle geometry and material's hydrophobicity. The plume geometry of pMDI aerosols can be influenced by the vapour pressure of the formulation, nozzle geometries and actuator material physiochemical properties.

Purpose To investigate the influence of different actuator nozzle designs on aerosol electrostatic charges and aerosol performances for pressurised metered dose inhalers (pMDIs).Methods Four actuator nozzle designs (flat, curved flat, cone and curved cone) were manufactured using insulating thermoplastics (PET and PTFE) and conducting metal (aluminium) materials. Aerosol electrostatic profiles of solution pMDI formulations containing propellant HFA 134a with different ethanol concentration and/or model drug beclomethasone dipropionate (BDP) were studied using a modified electrical low-pressure impactor (ELPI) for all actuator designs and materials. The mass of the deposited drug was analysed using high performance liquid chromatography (HPLC). Results Both curved nozzle designs for insulating PET and PTFE actuators significantly influenced aerosol electrostatics and aerosol performance compared with conducting aluminium actuator, where reversed charge polarity and higher throat deposition were observed with pMDI formulation containing BDP. Results are likely due to the changes in plume geometry caused by the curved edge nozzle designs and the bipolar charging nature of insulating materials.Conclusions This study demonstrated that actuator nozzle designs could significantly influence the electrostatic charges profiles and aerosol drug deposition pattern of pMDI aerosols, especially when using insulating thermoplastic materials where bipolar charging is more dominant.

This study investigated the effect of different active pharmaceutical ingredients (API) on aerosol electrostatic charges and aerosol performances for pressurized metered dose inhalers (pMDIs), using both insulating and conducting actuators.Five solution-based pMDIs containing different API ingredients including: beclomethasone dipropionate (BDP), budesonide (BUD), flunisolide (FS), salbutamol base (SB) and ipratropium bromide (IPBr) were prepared using pressure filling technique. Actuator blocks made from nylon, polytetrafluoroethylene (PTFE) and aluminium were manufactured with 0.3 mm nominal orifice diameter and cone nozzle shape. Aerosol electrostatics for each pMDI formulation and actuator were evaluated using the electrical low-pressure impactor (ELPI) and drug depositions were analysed using high performance liquid chromatography (HPLC).All three actuator materials showed the same net charge trend across the five active drug ingredients, with BDP, BUD and FS showing positive net charges for both nylon and PTFE actuators, respectively. While SB and IPBr had significantly negative net charges across the three different actuators, which correlates to the ionic functional groups present on the drug molecule structures.The API present in a pMDI has a dominant effect on the electrostatic properties of the formulation, overcoming the charge effect arising from the actuator materials. Results have shown that the electrostatic charges for a solution-based pMDI could be related to the interactions of the chemical ingredients and change in the work function for the overall formulation.

To investigate the influence of different actuator materials and nozzle designs on the electrostatic charge properties of a series of solution metered dose inhaler (pMDI) aerosols.

Soluble epoxide hydrolase (sEH, EPHX2) metabolizes eicosanoid epoxides, including epoxyeicosatrienoic acids (EETs) to the corresponding dihydroxyeicosatrienoic acids (DHETs), and leukotoxin (LTX) to leukotoxin diol (LTX diol). EETs, endothelium-derived hyperpolarizing factors, exhibit potentially beneficial properties, including anti-inflammatory effects and vasodilation. A novel, potent, selective inhibitor of recombinant human, rat and mouse sEH, GSK2256294A, exhibited potent cell-based activity, a concentration-dependent inhibition of the conversion of 14,15-EET to 14,15-DHET in human, rat and mouse whole blood in vitro, and a dose-dependent increase in the LTX/LTX diol ratio in rat plasma following oral administration. Mice receiving 10 days of cigarette smoke exposure concomitant with oral administration of GSK2256294A exhibited significant, dose-dependent reductions in pulmonary leukocytes and keratinocyte chemoattractant (KC, CXCL1) levels. Mice receiving oral administration of igarette smoke-exposure model nflammation GSK2256294A following 10 days of cigarette smoke exposure exhibited significant reductions in pulmonary leukocytes compared to vehicle-treated mice. These data indicate that GSK2256294A attenuates cigarette smoke-induced inflammation by both inhibiting its initiation and/or maintenance and promoting its resolution. Collectively, these data indicate that GSK2256294A would be an appropriate agent to evaluate the role of sEH in clinical studies, for example in diseases where cigarette smoke is a risk factor, ve pu such as chronic obstructi Abbreviations: sEH, soluble epoxide hydrolase; EETs, epoxyeicosatrienoic acids; HETs, dihydroxyeicosatrienoic acids; LTX, leukotoxin; LTX diol, leukotoxin diol; KC, eratinocyte chemoattractant; COPD, chronic obstructive pulmonary disease; sEHi, oluble epoxide hydrolase inhibitor(s); NF-kB, nuclear factorB; mEH, microsomal poxide hydrolase; BAL, bronchoalveolar lavage; VCAM-1, vascular cell adhesion olecule-1; ICAM-1, intercellular adhesion molecule-1; LPS, lipopolysaccharide. ∗ Corresponding author at: Stress & Repair Discovery Performance Unit, Respiraory Therapeutic Area, Mail Code UW2532, 709 Swedeland Road, GlaxoSmithKline, ing of Prussia, PA 19406, USA. Tel.: +1 610 270 5846; fax: +1 610 270 5381. E-mail address: patty.podolin@gsk.com (P.L. Podolin). 1 Present address: Department of Pharmaceutics, School of Pharmacy, Shenyang harmaceutical University, Shenyang, Liaoning 110016, PR China. 2 Present address: Clinical Pharmacology, Novartis, Florham Park, NJ 07932, USA. 3 Present address: Clinical Biomarkers, Oncology, GlaxoSmithKline, Collegeville, A 19426, USA. 098-8823/$ – see front matter © 2013 Elsevier Inc. All rights reserved. ttp://dx.doi.org/10.1016/j.prostaglandins.2013.02.001 lmonary disease (COPD) and cardiovascular disease. © 2013 Elsevier Inc. All rights reserved.

The role of T cells in chronic obstructive pulmonary disease (COPD) is not well understood. We have previously demonstrated that chronic cigarette smoke exposure can lead to the accumulation of CD4(+) and CD8(+) T cells in the alveolar airspaces in a mouse model of COPD, implicating these cells in disease pathogenesis. However, whether specific inhibition of T cell responses represents a therapeutic strategy has not been fully investigated. In this study inhibition of T cell responses through specific depleting antibodies, or the T cell immunosuppressant drug cyclosporin A, prevented airspace enlargement and neutrophil infiltration in a mouse model of chronic cigarette smoke exposure. Furthermore, individual inhibition of either CD4(+) T helper or CD8(+) T cytotoxic cells prevented airspace enlargement to a similar degree, implicating both T cell subsets as critical mediators of the adaptive immune response induced by cigarette smoke exposure. Importantly, T cell depletion resulted in significantly decreased levels of the Th17-associated cytokine IL-17A, and of caspase 3 and caspase 7 gene expression and activity, induced by cigarette smoke exposure. Finally, inhibition of T cell responses in a therapeutic manner also inhibited cigarette smoke-induced airspace enlargement, IL-17A expression, and neutrophil influx in mice. Together these data demonstrate for the first time that therapeutic inhibition of T cell responses may be efficacious in the treatment of COPD. Given that broad immunosuppression may be undesirable in COPD patients, this study provides proof-of-concept for more targeted approaches to inhibiting the role of T cells in emphysema development.

Soluble epoxide hydrolase (sEH, EPHX2) metabolizes eicosanoid epoxides, including epoxyeicosatrienoic acids (EETs) to the corresponding dihydroxyeicosatrienoic acids (DHETs), and leukotoxin (LTX) to leukotoxin diol (LTX diol). EETs, endothelium-derived hyperpolarizing factors, exhibit potentially beneficial properties, including anti-inflammatory effects and vasodilation. A novel, potent, selective inhibitor of recombinant human, rat and mouse sEH, GSK2256294A, exhibited potent cell-based activity, a concentration-dependent inhibition of the conversion of 14,15-EET to 14,15-DHET in human, rat and mouse whole blood in vitro, and a dose-dependent increase in the LTX/LTX diol ratio in rat plasma following oral administration. Mice receiving 10 days of cigarette smoke exposure concomitant with oral administration of GSK2256294A exhibited significant, dose-dependent reductions in pulmonary leukocytes and keratinocyte chemoattractant (KC, CXCL1) levels. Mice receiving oral administration of GSK2256294A following 10 days of cigarette smoke exposure exhibited significant reductions in pulmonary leukocytes compared to vehicle-treated mice. These data indicate that GSK2256294A attenuates cigarette smoke-induced inflammation by both inhibiting its initiation and/or maintenance and promoting its resolution. Collectively, these data indicate that GSK2256294A would be an appropriate agent to evaluate the role of sEH in clinical studies, for example in diseases where cigarette smoke is a risk factor, such as chronic obstructive pulmonary disease (COPD) and cardiovascular disease.

Yi Xin, Kiarash Emami, Puttisarn Mongkolwisetwara, Harrilla Profka, Garrett Greenan, Stephen J. Kadlecek, Stephen Pickup, Brian J. Bolognese, Edward R. Long III, Joseph P. Foley, Patricia L. Podolin, Masaru Ishii, and Rahim R. Rizi Radiology, University of Pennsylvania, Philadelphia, PA, United States, University of Pennsylvania, Philadelphia, PA, United States, Respiratory Therapeutic Area, GlaxoSmithKline, King of Prussia, PA, United States, Otolaryngology Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States