294 research outputs found
Dietary polyphenols mediated regulation of oxidative stress and chromatin remodeling in inflammation
Overcoming reduced glucocorticoid sensitivity in airway disease:molecular mechanisms and therapeutic approaches
Use of low-dose oral theophylline as an adjunct to inhaled corticosteroids in preventing exacerbations of chronic obstructive pulmonary disease: study protocol for a randomised controlled trial.
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with high morbidity, mortality, and health-care costs. An incomplete response to the anti-inflammatory effects of inhaled corticosteroids is present in COPD. Preclinical work indicates that 'low dose' theophylline improves steroid responsiveness. The Theophylline With Inhaled Corticosteroids (TWICS) trial investigates whether the addition of 'low dose' theophylline to inhaled corticosteroids has clinical and cost-effective benefits in COPD. METHOD/DESIGN: TWICS is a randomised double-blind placebo-controlled trial conducted in primary and secondary care sites in the UK. The inclusion criteria are the following: an established predominant respiratory diagnosis of COPD (post-bronchodilator forced expiratory volume in first second/forced vital capacity [FEV1/FVC] of less than 0.7), age of at least 40 years, smoking history of at least 10 pack-years, current inhaled corticosteroid use, and history of at least two exacerbations requiring treatment with antibiotics or oral corticosteroids in the previous year. A computerised randomisation system will stratify 1424 participants by region and recruitment setting (primary and secondary) and then randomly assign with equal probability to intervention or control arms. Participants will receive either 'low dose' theophylline (Uniphyllin MR 200 mg tablets) or placebo for 52 weeks. Dosing is based on pharmacokinetic modelling to achieve a steady-state serum theophylline of 1-5 mg/l. A dose of theophylline MR 200 mg once daily (or placebo once daily) will be taken by participants who do not smoke or participants who smoke but have an ideal body weight (IBW) of not more than 60 kg. A dose of theophylline MR 200 mg twice daily (or placebo twice daily) will be taken by participants who smoke and have an IBW of more than 60 kg. Participants will be reviewed at recruitment and after 6 and 12 months. The primary outcome is the total number of participant-reported COPD exacerbations requiring oral corticosteroids or antibiotics during the 52-week treatment period. DISCUSSION: The demonstration that 'low dose' theophylline increases the efficacy of inhaled corticosteroids in COPD by reducing the incidence of exacerbations is relevant not only to patients and clinicians but also to health-care providers, both in the UK and globally. TRIAL REGISTRATION: Current Controlled Trials ISRCTN27066620 was registered on Sept. 19, 2013, and the first subject was randomly assigned on Feb. 6, 2014
Quercetin prevents progression of disease in elastase/LPS-exposed mice by negatively regulating MMP expression
Abstract Background Chronic obstructive pulmonary disease (COPD) is characterized by chronic bronchitis, emphysema and irreversible airflow limitation. These changes are thought to be due to oxidative stress and an imbalance of proteases and antiproteases. Quercetin, a plant flavonoid, is a potent antioxidant and anti-inflammatory agent. We hypothesized that quercetin reduces lung inflammation and improves lung function in elastase/lipopolysaccharide (LPS)-exposed mice which show typical features of COPD, including airways inflammation, goblet cell metaplasia, and emphysema. Methods Mice treated with elastase and LPS once a week for 4 weeks were subsequently administered 0.5 mg of quercetin dihydrate or 50% propylene glycol (vehicle) by gavage for 10 days. Lungs were examined for elastance, oxidative stress, inflammation, and matrix metalloproteinase (MMP) activity. Effects of quercetin on MMP transcription and activity were examined in LPS-exposed murine macrophages. Results Quercetin-treated, elastase/LPS-exposed mice showed improved elastic recoil and decreased alveolar chord length compared to vehicle-treated controls. Quercetin-treated mice showed decreased levels of thiobarbituric acid reactive substances, a measure of lipid peroxidation caused by oxidative stress. Quercetin also reduced lung inflammation, goblet cell metaplasia, and mRNA expression of pro-inflammatory cytokines and muc5AC. Quercetin treatment decreased the expression and activity of MMP9 and MMP12 in vivo and in vitro, while increasing expression of the histone deacetylase Sirt-1 and suppressing MMP promoter H4 acetylation. Finally, co-treatment with the Sirt-1 inhibitor sirtinol blocked the effects of quercetin on the lung phenotype. Conclusions Quercetin prevents progression of emphysema in elastase/LPS-treated mice by reducing oxidative stress, lung inflammation and expression of MMP9 and MMP12.http://deepblue.lib.umich.edu/bitstream/2027.42/78260/1/1465-9921-11-131.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78260/2/1465-9921-11-131.pdfPeer Reviewe
Michel Foucault, Social Policy and 'Limit-Experience'
This thesis considers whether the discipline of social policy can validly use the patterns and intentions implicit in Foucault's critique of modernity to develop a new qualitative approach to social theory. He examined the conditions under which various regimes of social and political practice came into being; how they are maintained and the particular manner of their transformation. There are two specific emphases that establish the pattern of my overall inquiry. The first involves a reflection on the troubled and ineffectual place of normative social theory within contemporary social policy discourse. The second is a reconsideration of Foucault's oeuvre in relation to new social theory building within social policy. Both of these concerns offer an opportunity to reflect on the place of social theory within a discursive world that 'appears' cosmopolitan and diverse. Foucault famously declared that the point of philosophical activity involved the endeavour to know how and to what extent it might be possible to think differently - to examine the functioning of our ideas as 'limit-experiences'. He coined this phrase 'limit-experience' to outline his critique of the 'forms of rationalizations' that comprise the present practice of politics within modernity. He thought the decisive question was how apparently 'universal, necessary, and obligatory discourses about political and social knowledge shapes that which ought more properly to be regarded as 'singular, contingent, and the product of arbitrary constraints'. The former injunctive and 'magisterial' arguments that supported initial patterns of welfare state rhetoric are no longer persuasive. There has been a 'sea-change' in contemporary social ideas - from a welfare state to a welfare society - one that is breath-taking in its hegemonic compass. That world is increasingly depicted as a postmodern social world where there is little apparent respect for, let alone reliance on, the grand metaphors and social themes of classic social policy. This reconsideration of Foucault's ideas from a social policy perspective will not necessarily yield a new compelling normative rhetoric but it will provide an opportunity to think differently about the taken-for-granted nature of so much social policy theorizing. His portrayal of how we might 'think differently' about the multitude of practices involved in the rationalizations and subjectifications of 'limit-experiences' provides an opportunity to reflect on the patterning and practices that construct the current discourses of welfare and social policy. We do need to think differently or at least to see if it is possible to do so. Imagining difference, strategizing for it, and welcoming it, mark us out as constantly restless - a personal style that Foucault embraced with some gusto
Molecular vibrations in the presence of velocity-dependent forces
A semiclassical theory of small oscillations is developed for nuclei that are
subject to velocity-dependent forces in addition to the usual interatomic
forces. When the velocity-dependent forces are due to a strong magnetic field,
novel effects arise -- for example, the coupling of vibrational, rotational,
and translational modes. The theory is first developed using Newtonian
mechanics and we provide a simple quantification of the coupling between these
types of modes. We also discuss the mathematical structure of the problem,
which turns out to be a quadratic eigenvalue problem rather than a standard
eigenvalue problem. The theory is then re-derived using the Hamiltonian
formalism, which brings additional insight, including a close analogy to the
quantum-mechanical treatment of the problem. Finally, we provide numerical
examples for the H, HT, and HCN molecules in a strong magnetic field
Magnetic-Translational Sum Rule and Approximate Models of the Molecular Berry Curvature
The Berry connection and curvature are key components of electronic structure
calculations for atoms and molecules in magnetic fields. They ensure the
correct translational behavior of the effective nuclear Hamiltonian and the
correct center-of-mass motion during molecular dynamics in these environments.
In this work, we demonstrate how these properties of the Berry connection and
curvature arise from the translational symmetry of the electronic wave function
and how they are fully captured by a finite basis set of London orbitals but
not by standard Gaussian basis sets. This is illustrated by a series of
Hartree-Fock calculations on small molecules in different basis sets. Based on
the resulting physical interpretation of the Berry curvature as the shielding
of the nuclei by the electrons, we introduce and test a series of
approximations using the Mulliken fragmentation scheme of the electron density.
These approximations will be particularly useful in ab initio molecular
dynamics calculations in a magnetic field, since they reduce the computational
cost, while recovering the correct physics and up to 95% of the exact Berry
curvature
Non-adiabatic coupling matrix elements in a magnetic field: geometric gauge dependence and Berry phase
Non-adiabatic coupling matrix elements (NACMEs) are important in quantum
chemistry, particularly for molecular dynamics methods such as surface hopping.
However, NACMEs are gauge dependent. This presents a difficulty for their
calculation in general, where there are no restrictions on the gauge function
except that it be differentiable. These cases are relevant for complex-valued
electronic wave functions, such as those that arise in the presence of a
magnetic field or spin-orbit coupling. Additionally, the Berry curvature and
Berry force play an important role in molecular dynamics in a magnetic field,
and are also relevant in the context of spin-orbit coupling. For methods such
as surface hopping, excited-state Berry curvatures will also be of interest.
With this in mind, we have developed a scheme for the calculation of
continuous, differentiable NACMEs as a function of the molecular geometry for
complex-valued wave functions. We demonstrate the efficacy of the method by
using the H molecule at the full configuration-interaction (FCI) level of
theory. Additionally, ground- and excited- state Berry curvatures are computed
for the first time using FCI theory. Finally, Berry phases are computed
directly in terms of diagonal NACMEs
Long-acting inhaled therapy (beta-agonists, anticholinergics and steroids) for COPD: a network meta-analysis.
BACKGROUND: Pharmacological therapy for chronic obstructive pulmonary disease (COPD) is aimed at relieving symptoms, improving quality of life and preventing or treating exacerbations.Treatment tends to begin with one inhaler, and additional therapies are introduced as necessary. For persistent or worsening symptoms, long-acting inhaled therapies taken once or twice daily are preferred over short-acting inhalers. Several Cochrane reviews have looked at the risks and benefits of specific long-acting inhaled therapies compared with placebo or other treatments. However for patients and clinicians, it is important to understand the merits of these treatments relative to each other, and whether a particular class of inhaled therapies is more beneficial than the others. OBJECTIVES: To assess the efficacy of treatment options for patients whose chronic obstructive pulmonary disease cannot be controlled by short-acting therapies alone. The review will not look at combination therapies usually considered later in the course of the disease.As part of this network meta-analysis, we will address the following issues.1. How does long-term efficacy compare between different pharmacological treatments for COPD?2. Are there limitations in the current evidence base that may compromise the conclusions drawn by this network meta-analysis? If so, what are the implications for future research? SEARCH METHODS: We identified randomised controlled trials (RCTs) in existing Cochrane reviews by searching the Cochrane Database of Systematic Reviews (CDSR). In addition, we ran a comprehensive citation search on the Cochrane Airways Group Register of trials (CAGR) and checked manufacturer websites and reference lists of other reviews. The most recent searches were conducted in September 2013. SELECTION CRITERIA: We included parallel-group RCTs of at least 6 months' duration recruiting people with COPD. Studies were included if they compared any of the following treatments versus any other: long-acting beta2-agonists (LABAs; formoterol, indacaterol, salmeterol); long-acting muscarinic antagonists (LAMAs; aclidinium, glycopyrronium, tiotropium); inhaled corticosteroids (ICSs; budesonide, fluticasone, mometasone); combination long-acting beta2-agonist (LABA) and inhaled corticosteroid (LABA/ICS) (formoterol/budesonide, formoterol/mometasone, salmeterol/fluticasone); and placebo. DATA COLLECTION AND ANALYSIS: We conducted a network meta-analysis using Markov chain Monte Carlo methods for two efficacy outcomes: St George's Respiratory Questionnaire (SGRQ) total score and trough forced expiratory volume in one second (FEV1). We modelled the relative effectiveness of any two treatments as a function of each treatment relative to the reference treatment (placebo). We assumed that treatment effects were similar within treatment classes (LAMA, LABA, ICS, LABA/ICS). We present estimates of class effects, variability between treatments within each class and individual treatment effects compared with every other.To justify the analyses, we assessed the trials for clinical and methodological transitivity across comparisons. We tested the robustness of our analyses by performing sensitivity analyses for lack of blinding and by considering six- and 12-month data separately. MAIN RESULTS: We identified 71 RCTs randomly assigning 73,062 people with COPD to 184 treatment arms of interest. Trials were similar with regards to methodology, inclusion and exclusion criteria and key baseline characteristics. Participants were more often male, aged in their mid sixties, with FEV1 predicted normal between 40% and 50% and with substantial smoking histories (40+ pack-years). The risk of bias was generally low, although missing information made it hard to judge risk of selection bias and selective outcome reporting. Fixed effects were used for SGRQ analyses, and random effects for Trough FEV1 analyses, based on model fit statistics and deviance information criteria (DIC). SGRQ SGRQ data were available in 42 studies (n = 54,613). At six months, 39 pairwise comparisons were made between 18 treatments in 25 studies (n = 27,024). Combination LABA/ICS was the highest ranked intervention, with a mean improvement over placebo of -3.89 units at six months (95% credible interval (CrI) -4.70 to -2.97) and -3.60 at 12 months (95% CrI -4.63 to -2.34). LAMAs and LABAs were ranked second and third at six months, with mean differences of -2.63 (95% CrI -3.53 to -1.97) and -2.29 (95% CrI -3.18 to -1.53), respectively. Inhaled corticosteroids were ranked fourth (MD -2.00, 95% CrI -3.06 to -0.87). Class differences between LABA, LAMA and ICS were less prominent at 12 months. Indacaterol and aclidinium were ranked somewhat higher than other members of their classes, and formoterol 12 mcg, budesonide 400 mcg and formoterol/mometasone combination were ranked lower within their classes. There was considerable overlap in credible intervals and rankings for both classes and individual treatments. Trough FEV1 Trough FEV1 data were available in 46 studies (n = 47,409). At six months, 41 pairwise comparisons were made between 20 treatments in 31 studies (n = 29,271). As for SGRQ, combination LABA/ICS was the highest ranked class, with a mean improvement over placebo of 133.3 mL at six months (95% CrI 100.6 to 164.0) and slightly less at 12 months (mean difference (MD) 100, 95% CrI 55.5 to 140.1). LAMAs (MD 103.5, 95% CrI 81.8 to 124.9) and LABAs (MD 99.4, 95% CrI 72.0 to 127.8) showed roughly equivalent results at six months, and ICSs were the fourth ranked class (MD 65.4, 95% CrI 33.1 to 96.9). As with SGRQ, initial differences between classes were not so prominent at 12 months. Indacaterol and salmeterol/fluticasone were ranked slightly better than others in their class, and formoterol 12, aclidinium, budesonide and formoterol/budesonide combination were ranked lower within their classes. All credible intervals for individual rankings were wide. AUTHORS' CONCLUSIONS: This network meta-analysis compares four different classes of long-acting inhalers for people with COPD who need more than short-acting bronchodilators. Quality of life and lung function were improved most on combination inhalers (LABA and ICS) and least on ICS alone at 6 and at 12 months. Overall LAMA and LABA inhalers had similar effects, particularly at 12 months. The network has demonstrated the benefit of ICS when added to LABA for these outcomes in participants who largely had an FEV1 that was less than 50% predicted, but the additional expense of combination inhalers and any potential for increased adverse events (which has been established by other reviews) require consideration. Our findings are in keeping with current National Institute for Health and Care Excellence (NICE) guidelines
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