202 research outputs found
A Comparison of Physical Activity Between Home-Based and Centre-Based Pulmonary Rehabilitation:A Randomised Controlled Secondary Analysis
Background: Pulmonary rehabilitation (PR) is a highly effective intervention for individuals with chronic obstructive pulmonary disease (COPD). Physical activity (PA) has been shown to increase after a centre-based programme, yet it is not clear if a home-based programme can offer the same benefit. This study aimed to evaluate the effect of home-based PR compared with the centre-based PR on the PA levels post 7 weeks of PR and 6 months follow-up.Method: In this study, 51 participants with COPD, of them, 36 (71%) men completed physical activity monitoring with a SenseWear Armband, at three time points (baseline, 7 weeks, and 6 months). The participants were randomly assigned to either centre-based supervised PR (n = 25; 69 ± 6 years; FEV1 55 ± 20% predicted) or home-based PR (n = 26; 68 ± 7 years; FEV1 42 ± 19% predicted) programmes lasting 7 weeks. The home-based programme includes one hospital visit, a self-management manual, and two telephone calls. The PA was measured as step count, time in moderate PA (3–6 metabolic equivalent of tasks [METs]) in bouts of more than 10 min and sedentary time (<2 METs).Results: Home-based PR increased step count significantly more than the centre-based PR after 7 weeks (mean difference 1,463 steps: 95% CI 280–2,645, p = 0.02). There was no difference in time spent in moderate PA was observed (mean difference 62 min: 95% CI −56 to 248, p = 0.24). Sedentary behaviour was also significantly different between the centre and home-based groups. The home group spent 52 min less time sedentary compared with the centre-based (CI −106 to 2, p = 0.039). However, after 6 months, the step count and time spent in moderate PA returned to baseline in both the groups.Conclusion: This study provides an important insight into the role of home-based PR which has the potential to be offered as an alternative to the centre-based PR. Understanding who may best respond from the centre or home-based PR warrants further exploration and how to maintain these initial benefits for the long-term.Trial Registry: ISRCTN: No.: ISRCTN81189044; URL: isrctn.com
Differential effects of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 on atherosclerosis and monocyte/macrophage invasion
AIMS: MMPs contribute to atherosclerotic plaque progression and instability, but the relative potency of their endogenous tissue inhibitors of metalloproteinases (TIMPs) as protective factors has not been defined. We therefore investigated the impact of TIMP-1 and TIMP-2 knockout on atherosclerotic plaque burden and composition in apolipoprotein E-knockout (Apoe(−/−)) mice and studied the underlying effects on monocyte/macrophage behaviour. METHODS AND RESULTS: Analysis of brachiocephalic artery plaques revealed comparable atherosclerotic lesion areas between TIMP-1(−/−) Apoe(−/−) or TIMP-2(−/−) Apoe(−/−) double deficient mice and relevant age-matched, strain-matched Apoe(−/−) controls after 8 weeks of high-fat feeding. However, lesions from TIMP-2(−/−) Apoe(−/−) mice had higher levels of markers associated with plaque vulnerability, including increased macrophage: vascular smooth muscle cell ratios, larger necrotic core areas, reduced collagen contents, increased macrophage proliferation, and apoptosis frequencies, compared with TIMP-1(−/−)Apoe(−/−) and controls. In contrast, TIMP-1(−/−) Apoe(−/−) animals only had a significant reduction in vascular smooth muscle cell content compared with Apoe(−/−) controls. In vitro and in vivo findings implicated heightened monocyte/macrophage invasion in the detrimental effects observed on atherosclerotic plaque composition in TIMP-2(−/−) Apoe(−/−) mice. Moreover, TIMP-2 specifically decreased MMP-14-dependent monocyte/macrophage infiltration into sites of experimentally induced inflammation and established atherosclerotic lesions. CONCLUSION: Our data demonstrate that TIMP-2 plays a greater protective role than TIMP-1 during the pathogenesis of atherosclerosis, in part by suppressing MMP-14-dependent monocyte/macrophage accumulation into plaques
Community engagement and population coverage in mass anti-malarial administrations: a systematic literature review
BACKGROUND: Mass anti-malarial administration has been proposed as a key component of the malaria elimination strategy in South East Asia. The success of this approach depends on the local malaria epidemiology, nature of the anti-malarial regimen and population coverage. Community engagement is used to promote population coverage but little research has systematically analysed its impact. This systematic review examines population coverage and community engagement in programmes of mass anti-malarial drug administration. METHODS: This review builds on a previous review that identified 3049 articles describing mass anti-malarial administrations published between 1913 and 2011. Further search and application of a set of criteria conducted in the current review resulted in 51 articles that were retained for analysis. These 51 papers described the population coverage and/or community engagement in mass anti-malarial administrations. Population coverage was quantitatively assessed and a thematic analysis was conducted on the community engagement activities. RESULTS: The studies were conducted in 26 countries: in diverse healthcare and social contexts where various anti-malarial regimens under varied study designs were administered. Twenty-eight articles reported only population coverage; 12 described only community engagement activities; and 11 community engagement and population coverage. Average population coverage was 83% but methods of calculating coverage were frequently unclear or inconsistent. Community engagement activities included providing health education and incentives, using community structures (e.g. existing hierarchies or health infrastructure), mobilizing human resources, and collaborating with government at some level (e.g. ministries of health). Community engagement was often a process involving various activities throughout the duration of the intervention. CONCLUSION: The mean population coverage was over 80% but incomplete reporting of calculation methods limits conclusions and comparisons between studies. Various community engagement activities and approaches were described, but many articles contained limited or no details. Other factors relevant to population coverage, such as the social, cultural and study context were scarcely reported. Further research is needed to understand the factors that influence population coverage and adherence in mass anti-malarial administrations and the role community engagement activities and approaches play in satisfactory participation
Galectin-3 identifies a subset of macrophages with a potential beneficial role in atherosclerosis:Macrophage galectin-3 prevents plaque progression
Plastid Transcript Editing across Dinoflagellate Lineages Shows Lineage-Specific Application but Conserved Trends.
Dinoflagellates are a group of unicellular protists with immense ecological and evolutionary significance and cell biological diversity. Of the photosynthetic dinoflagellates, the majority possess a plastid containing the pigment peridinin, whereas some lineages have replaced this plastid by serial endosymbiosis with plastids of distinct evolutionary affiliations, including a fucoxanthin pigment-containing plastid of haptophyte origin. Previous studies have described the presence of widespread substitutional RNA editing in peridinin and fucoxanthin plastid genes. Because reports of this process have been limited to manual assessment of individual lineages, global trends concerning this RNA editing and its effect on the biological function of the plastid are largely unknown. Using novel bioinformatic methods, we examine the dynamics and evolution of RNA editing over a large multispecies data set of dinoflagellates, including novel sequence data from the peridinin dinoflagellate Pyrocystis lunula and the fucoxanthin dinoflagellate Karenia mikimotoi. We demonstrate that while most individual RNA editing events in dinoflagellate plastids are restricted to single species, global patterns, and functional consequences of editing are broadly conserved. We find that editing is biased toward specific codon positions and regions of genes, and generally corrects otherwise deleterious changes in the genome prior to translation, though this effect is more prevalent in peridinin than fucoxanthin lineages. Our results support a model for promiscuous editing application subsequently shaped by purifying selection, and suggest the presence of an underlying editing mechanism transferred from the peridinin-containing ancestor into fucoxanthin plastids postendosymbiosis, with remarkably conserved functional consequences in the new lineage
Progressive and biased divergent evolution underpins the origin and diversification of peridinin dinoflagellate plastids
Dinoflagellates are algae of tremendous importance to ecosystems and to public health. The cell biology and genome organization of dinoflagellate species is highly unusual. For example, the plastid genomes of peridinin-containing dinoflagellates encode only a minimal number of genes arranged on small elements termed "minicircles". Previous studies of peridinin plastid genes have found evidence for divergent sequence evolution, including extensive substitutions, novel insertions and deletions, and use of alternative translation initiation codons. Understanding the extent of this divergent evolution has been hampered by the lack of characterized peridinin plastid sequences. We have identified over 300 previously unannotated peridinin plastid mRNAs from published transcriptome projects, vastly increasing the number of sequences available. Using these data, we have produced a well-resolved phylogeny of peridinin plastid lineages, which uncovers several novel relationships within the dinoflagellates. This enables us to define changes to plastid sequences that occurred early in dinoflagellate evolution, and that have contributed to the subsequent diversification of individual dinoflagellate clades. We find that the origin of the peridinin dinoflagellates was specifically accompanied by elevations both in the overall number of substitutions that occurred on plastid sequences, and in the Ka/Ks ratio associated with plastid sequences, consistent with changes in selective pressure. These substitutions, alongside other changes, have accumulated progressively in individual peridinin plastid lineages. Throughout our entire dataset, we identify a persistent bias toward non-synonymous substitutions occurring on sequences encoding photosystem I subunits and stromal regions of peridinin plastid proteins, which may have underpinned the evolution of this unusual organelle.Wellcome Trus
Role of the endothelium in the vascular effects of the thrombin receptor (protease-activated receptor type 1) in humans
ObjectivesThe purpose of this study was to determine the role of the endothelium in the vascular actions of protease-activated receptor type 1 (PAR-1) activation in vivo in man.BackgroundThrombin is central to the pathophysiology of atherothrombosis. Its cellular actions are mediated via PAR-1. Protease-activated receptor type 1 activation causes arterial vasodilation, venoconstriction, platelet activation, and tissue-type plasminogen activator release in man.MethodsDorsal hand vein diameter was measured in 6 healthy volunteers before and after endothelial denudation. Forearm arterial blood flow, plasma fibrinolytic factors, and platelet activation were measured in 24 healthy volunteers during venous occlusion plethysmography. The effects of inhibition of prostacyclin, nitric oxide (NO), and endothelium-derived hyperpolarizing factor on PAR-1 responses were assessed during coadministration of aspirin, the “NO clamp” (L-NG-monomethyl arginine and sodium nitroprusside), and tetraethylammonium ion, respectively.ResultsEndothelial denudation did not affect PAR-1–evoked venoconstriction (SFLLRN; 0.05 to 15 nmol/min). Although aspirin had no effect, SFLLRN-induced vasodilation (5 to 50 nmol/min) was attenuated by the NO clamp (p < 0.0001) and tetraethylammonium ion (p < 0.05) and abolished by their combination (p < 0.01). The NO clamp augmented SFLLRN-induced tissue-type plasminogen activator and plasminogen activator inhibitor type 1 antigen (p < 0.0001) release, but tetraethylammonium ion and aspirin had no effect. SFLLRN-induced platelet activation was unaffected by NO or prostacyclin inhibition.ConclusionsActing via PAR-1, thrombin causes contrasting effects in the human vasculature and has a major interaction with the endothelium. This highlights the critical importance of endothelial function during acute arterial injury and intravascular thrombosis, as occurs in cardiovascular events including myocardial infarction and stroke
The dual endothelin converting enzyme/neutral endopeptidase inhibitor SLV-306 (daglutril), inhibits systemic conversion of big endothelin-1 in humans
Aims - Inhibition of neutral endopeptidases (NEP) results in a beneficial increase in plasma concentrations of natriuretic peptides such as ANP. However NEP inhibitors were ineffective anti-hypertensives, probably because NEP also degrades vasoconstrictor peptides, including endothelin-1 (ET-1). Dual NEP and endothelin converting enzyme (ECE) inhibition may be more useful. The aim of the study was to determine whether SLV-306 (daglutril), a combined ECE/NEP inhibitor, reduced the systemic conversion of big ET-1 to the mature peptide. Secondly, to determine whether plasma ANP levels were increased.
Main methods - Following oral administration of three increasing doses of SLV-306 (to reach an average target concentration of 75, 300, 1200 ng ml− 1 of the active metabolite KC-12615), in a randomised, double blinded regime, big ET-1 was infused into thirteen healthy male volunteers. Big ET-1 was administered at a rate of 8 and 12 pmol kg− 1 min− 1 (20 min each). Plasma samples were collected pre, during and post big ET-1 infusion. ET-1, C-terminal fragment (CTF), big ET-1, and atrial natriuretic peptide (ANP) were measured.
Key findings - At the two highest concentrations tested, SLV-306 dose dependently attenuated the rise in blood pressure after big ET-1 infusion. There was a significant increase in circulating big ET-1 levels, compared with placebo, indicating that SLV-306 was inhibiting an increasing proportion of endogenous ECE activity. Plasma ANP concentrations also significantly increased, consistent with systemic NEP inhibition.
Significance - SLV-306 leads to inhibition of both NEP and ECE in humans. Simultaneous augmentation of ANP and inhibition of ET-1 production is of potential therapeutic benefit in cardiovascular disease
Directly photoexcited Dirac and Weyl fermions in ZrSiS and NbAs
We report ultrafast optical measurements of the Dirac line-node semimetal ZrSiS and the Weyl semimetal NbAs, using mid-infrared pump photons from 86 meV to 500 meV to directly excite Dirac and Weyl fermions within the linearly dispersing bands. In NbAs, the photoexcited Weyl fermions initially form a non-thermal distribution, signified by a brief spike in the differential reflectivity whose sign is controlled by the relative energy of the pump and probe photons. In ZrSiS, electron-electron scattering rapidly thermalizes the electrons, and the spike is not observed. Subsequently, hot carriers in both materials cool within a few picoseconds. This cooling, as seen in the two materials’ differential reflectivity, differs in sign, shape, and timescale. Nonetheless, we find that it may be described in a simple model of thermal electrons, without free parameters. The electronic cooling in ZrSiS is particularly fast, which may make the material useful for optoelectronic applications
Impact of Scotland’s comprehensive, smoke-free legislation on stroke
<p>Background: Previous studies have reported a reduction in acute coronary events following smoke-free legislation.
Evidence is lacking on whether stroke is also reduced. The aim was to determine whether the incidence of stroke, overalland by sub-type, fell following introduction of smoke-free legislation across Scotland on 26 March 2006.</p>
<p>Methods and Findings: A negative binomial regression model was used to determine whether the introduction of smokefree legislation resulted in a step and/or slope change in stroke incidence. The model was adjusted for age-group, sex, socioeconomic deprivation quintile, urban/rural residence and month. Interaction tests were also performed. Routine hospital administrative data and death certificates were used to identify all hospital admissions and pre-hospital deaths due to stroke (ICD10 codes I61, I63 and I64) in Scotland between 2000 and 2010 inclusive. Prior to the legislation, rates of all stroke, intracerebral haemorrhage and unspecified stroke were decreasing, whilst cerebral infarction was increasing at 0.97% per annum. Following the legislation, there was a dramatic fall in cerebral infarctions that persisted for around 20
months. No visible effect was observed for other types of stroke. The model confirmed an 8.90% (95% CI 4.85, 12.77,
p,0.001) stepwise reduction in cerebral infarction at the time the legislation was implemented, after adjustment for
potential cofounders.</p>
<p>Conclusions: Following introduction of national, comprehensive smoke-free legislation there was a selective reduction in cerebral infarction that was not apparent in other types of stroke.</p>
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