110 research outputs found

    Inhaled corticosteroids for chronic obstructive pulmonary disease-the shifting treatment paradigm

    Get PDF
    Chronic obstructive pulmonary disease (COPD) guidelines suggest using inhaled corticosteroids (ICS) in patients with severe airflow limitation or those at high risk of exacerbations. This recommendation is based on evidence demonstrating that ICS, especially when prescribed in fixed-dose combinations (FDC) with long-acting ฮฒ2 agonists (LABA), improve quality of life (QoL), decrease exacerbations and hospitalisations, and have been associated with a trend towards a reduction in all-cause mortality. Audit shows that routine prescribing practice frequently uses inhaler therapies outside current guidelines recommendations; severe to very severe disease constitutes about 20% of all COPD patients, but up to 75% of COPD patients are prescribed an ICS, with significant numbers given ICS/LABA as first-line maintenance therapy. The role of ICS in the treatment paradigm for COPD is changing, driven by the growing evidence of increased risk of pneumonia, and the introduction of a new class of FDC; LABA and long-acting muscarinic antagonists (LAMA), which simplify dual bronchodilation and present a plausible alternative therapy. As the evidence base for dual therapy bronchodilation expands, it is likely that maximal bronchodilation will move up the treatment algorithm and ICS reserved for those with more severe disease who are not controlled on dual therapy. This change has already manifested in local COPD algorithms, such as those at Tayside, and represents a significant change in recommended prescribing practice. This review reassesses the role of ICS in the shifting treatment paradigm, in the context of alternative treatment options that provide maximal bronchodilation

    Mechanical properties of the compass depressors of the sea-urchin Paracentrotus lividus (Echinodermata, Echinoidea) and the effects of enzymes, neurotransmitters and synthetic tensilin-like protein

    Get PDF
    The compass depressors (CDs) of the sea-urchin lantern are ligaments consisting mainly of discontinuous collagen fibrils associated with a small population of myocytes. They are mutable collagenous structures, which can change their mechanical properties rapidly and reversibly under nervous control. The aims of this investigation were to characterise the baseline (i.e. unmanipulated) static mechanical properties of the CDs of Paracentrotus lividus by means of creep tests and incremental force-extension tests, and to determine the effects on their mechanical behaviour of a range of agents. Under constant load the CDs exhibited a three-phase creep curve, the mean coefficient of viscosity being 561ยฑ365 MPa.s. The stress-strain curve showed toe, linear and yield regions; the mean strain at the toe-linear inflection was 0.86ยฑ0.61; the mean Young's modulus was 18.62ยฑ10.30 MPa; and the mean tensile strength was 8.14ยฑ5.73 MPa. Hyaluronidase from Streptomyces hyalurolyticus had no effect on creep behaviour, whilst chondroitinase ABC prolonged primary creep but had no effect on secondary creep or on any force-extension parameters; it thus appears that neither hyaluronic acid nor sulphated glycosaminoglycans have an interfibrillar load transfer function in the CD. Acetylcholine, the muscarinic agonists arecoline and methacholine, and the nicotinic agonists nicotine and 1-[1-(3,4-dimethyl-phenyl)-ethyl]-piperazine produced an abrupt increase in CD viscosity; the CDs were not differentially sensitive to muscarinic or nicotinic agonists. CDs showed either no, or no consistent, response to adrenaline, L-glutamic acid, 5-hydroxytryptamine and ฮณ-aminobutyric acid. Synthetic echinoid tensilin-like protein had a weak and inconsistent stiffening effect, indicating that, in contrast to holothurian tensilins, the echinoid molecule may not be involved in the regulation of collagenous tissue tensility. We compare in detail the mechanical behaviour of the CD with that of mammalian tendon and highlight its potential as a model system for investigating poorly understood aspects of the ontogeny and phylogeny of vertebrate collagenous tissues.(undefined)info:eu-repo/semantics/publishedVersio

    GoLoco motif proteins binding to Gฮฑi1: insights from molecular simulations

    Get PDF
    Molecular dynamics simulations, computational alanine scanning and sequence analysis were used to investigate the structural properties of the Gฮฑi1/GoLoco peptide complex. Using these methodologies, binding of the GoLoco motif peptide to the Gฮฑi1 subunit was found to restrict the relative movement of the helical and catalytic domains in the Gฮฑi1 subunit, which is in agreement with a proposed mechanism of GDP dissociation inhibition by GoLoco motif proteins. In addition, the results provide further insights into the role of the โ€œSwitch IVโ€ region located within the helical domain of Gฮฑ, the conformation of which might be important for interactions with various Gฮฑ partners

    Measuring local depletion of terrestrial game vertebrates by central-place hunters in rural Amazonia

    Get PDF
    The degree to which terrestrial vertebrate populations are depleted in tropical forests occupied by human communities has been the subject of an intense polarising debate that has important conservation implications. Conservation ecologists and practitioners are divided over the extent to which community-based subsistence offtake is compatible with ecologically functional populations of tropical forest game species. To quantify depletion envelopes of forest vertebrates around human communities, we deployed a total of 383 camera trap stations and 78 quantitative interviews to survey the peri-community areas controlled by 60 semi-subsistence communities over a combined area of over 3.2 million hectares in the Mรฉdio Juruรก and Uatumรฃ regions of Central-Western Brazilian Amazonia. Our results largely conform with prior evidence that hunting large-bodied vertebrates reduces wildlife populations near settlements, such that they are only found at a distance to settlements where they are hunted less frequently. Camera trap data suggest that a select few harvest-sensitive species, including lowland tapir, are either repelled or depleted by human communities. Nocturnal and cathemeral species were detected relatively more frequently in disturbed areas close to communities, but individual species did not necessarily shift their activity patterns. Group biomass of all species was depressed in the wider neighbourhood of urban areas rather than communities. Interview data suggest that species traits, especially group size and body mass, mediate these relationships. Large-bodied, large-group-living species are detected farther from communities as reported by experienced informants. Long-established communities in our study regions have not โ€œemptiedโ€ the surrounding forest. Low human population density and low hunting offtake due to abundant sources of alternative aquatic protein, suggest that these communities represent a best-case scenario for sustainable hunting of wildlife for food, thereby providing a conservative assessment of game depletion. Given this โ€˜best-caseโ€™ camera trap and interview-based evidence for hunting depletion, regions with higher human population densities, external trade in wildlife and limited access to alternative protein will likely exhibit more severe depletion

    RNA localization in neurite morphogenesis and synaptic regulation: current evidence and novel approaches

    Get PDF
    It is now generally accepted that RNA localization in the central nervous system conveys important roles both during development and in the adult brain. Of special interest is protein synthesis located at the synapse, as this potentially confers selective synaptic modification and has been implicated in the establishment of memories. However, the underlying molecular events are largely unknown. In this review, we will first discuss novel findings that highlight the role of RNA localization in neurons. We will focus on the role of RNA localization in neurotrophin signaling, axon outgrowth, dendrite and dendritic spine morphogenesis as well as in synaptic plasticity. Second, we will briefly present recent work on the role of microRNAs in translational control in dendrites and its implications for learning and memory. Finally, we discuss recent approaches to visualize RNAs in living cells and their employment for studying RNA trafficking in neurons

    Distinct Peripheral Blood RNA Responses to Salmonella in Pigs Differing in Salmonella Shedding Levels: Intersection of IFNG, TLR and miRNA Pathways

    Get PDF
    Transcriptomic analysis of the response to bacterial pathogens has been reported for several species, yet few studies have investigated the transcriptional differences in whole blood in subjects that differ in their disease response phenotypes. Salmonella species infect many vertebrate species, and pigs colonized with Salmonella enterica serovar Typhimurium (ST) are usually asymptomatic, making detection of these Salmonella-carrier pigs difficult. The variable fecal shedding of Salmonella is an important cause of foodborne illness and zoonotic disease. To investigate gene pathways and biomarkers associated with the variance in Salmonella shedding following experimental inoculation, we initiated the first analysis of the whole blood transcriptional response induced by Salmonella. A population of pigs (nโ€Š=โ€Š40) was inoculated with ST and peripheral blood and fecal Salmonella counts were collected between 2 and 20 days post-inoculation (dpi). Two groups of pigs with either low shedding (LS) or persistent shedding (PS) phenotypes were identified. Global transcriptional changes in response to ST inoculation were identified by Affymetrix Genechipยฎ analysis of peripheral blood RNA at day 0 and 2 dpi. ST inoculation triggered substantial gene expression changes in the pigs and there was differential expression of many genes between LS and PS pigs. Analysis of the differential profiles of gene expression within and between PS and LS phenotypic classes identified distinct regulatory pathways mediated by IFN-ฮณ, TNF, NF-ฮบB, or one of several miRNAs. We confirmed the activation of two regulatory factors, SPI1 and CEBPB, and demonstrated that expression of miR-155 was decreased specifically in the PS animals. These data provide insight into specific pathways associated with extremes in Salmonella fecal shedding that can be targeted for further exploration on why some animals develop a carrier state. This knowledge can also be used to develop rational manipulations of genetics, pharmaceuticals, nutrition or husbandry methods to decrease Salmonella colonization, shedding and spread
    • โ€ฆ
    corecore