208 research outputs found

    Elevation in Body Temperature to Fever Range Enhances and Prolongs Subsequent Responsiveness of Macrophages to Endotoxin Challenge

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    Macrophages are often considered the sentries in innate immunity, sounding early immunological alarms, a function which speeds the response to infection. Compared to the large volume of studies on regulation of macrophage function by pathogens or cytokines, relatively little attention has been devoted to the role of physical parameters such as temperature. Given that temperature is elevated during fever, a long-recognized cardinal feature of inflammation, it is possible that macrophage function is responsive to thermal signals. To explore this idea, we used LPS to model an aseptic endotoxin-induced inflammatory response in BALB/c mice and found that raising mouse body temperature by mild external heat treatment significantly enhances subsequent LPS-induced release of TNF-α into the peritoneal fluid. It also reprograms macrophages, resulting in sustained subsequent responsiveness to LPS, i.e., this treatment reduces “endotoxin tolerance” in vitro and in vivo. At the molecular level, elevating body temperature of mice results in a increase in LPS-induced downstream signaling including enhanced phosphorylation of IKK and IκB, NF-κB nuclear translocation and binding to the TNF-α promoter in macrophages upon secondary stimulation. Mild heat treatment also induces expression of HSP70 and use of HSP70 inhibitors (KNK437 or Pifithrin-µ) largely abrogates the ability of the thermal treatment to enhance TNF-α, suggesting that the induction of HSP70 is important for mediation of thermal effects on macrophage function. Collectively, these results support the idea that there has been integration between the evolution of body temperature regulation and macrophage function that could help to explain the known survival benefits of fever in organisms following infection

    No more 'business as usual' with audit and feedback interventions: towards an agenda for a reinvigorated intervention

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    Background: Audit and feedback interventions in healthcare have been found to be effective, but there has been little progress with respect to understanding their mechanisms of action or identifying their key ‘active ingredients.’ Discussion: Given the increasing use of audit and feedback to improve quality of care, it is imperative to focus further research on understanding how and when it works best. In this paper, we argue that continuing the ‘business as usual’ approach to evaluating two-arm trials of audit and feedback interventions against usual care for common problems and settings is unlikely to contribute new generalizable findings. Future audit and feedback trials should incorporate evidence- and theory-based best practices, and address known gaps in the literature. Summary: We offer an agenda for high-priority research topics for implementation researchers that focuses on reviewing best practices for designing audit and feedback interventions to optimize effectiveness

    Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways

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    It is of considerable translational importance whether depression is a form or a consequence of sickness behavior. Sickness behavior is a behavioral complex induced by infections and immune trauma and mediated by pro-inflammatory cytokines. It is an adaptive response that enhances recovery by conserving energy to combat acute inflammation. There are considerable phenomenological similarities between sickness behavior and depression, for example, behavioral inhibition, anorexia and weight loss, and melancholic (anhedonia), physio-somatic (fatigue, hyperalgesia, malaise), anxiety and neurocognitive symptoms. In clinical depression, however, a transition occurs to sensitization of immuno-inflammatory pathways, progressive damage by oxidative and nitrosative stress to lipids, proteins, and DNA, and autoimmune responses directed against self-epitopes. The latter mechanisms are the substrate of a neuroprogressive process, whereby multiple depressive episodes cause neural tissue damage and consequent functional and cognitive sequelae. Thus, shared immuno-inflammatory pathways underpin the physiology of sickness behavior and the pathophysiology of clinical depression explaining their partially overlapping phenomenology. Inflammation may provoke a Janus-faced response with a good, acute side, generating protective inflammation through sickness behavior and a bad, chronic side, for example, clinical depression, a lifelong disorder with positive feedback loops between (neuro)inflammation and (neuro)degenerative processes following less well defined triggers

    VDA, a Method of Choosing a Better Algorithm with Fewer Validations

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    The multitude of bioinformatics algorithms designed for performing a particular computational task presents end-users with the problem of selecting the most appropriate computational tool for analyzing their biological data. The choice of the best available method is often based on expensive experimental validation of the results. We propose an approach to design validation sets for method comparison and performance assessment that are effective in terms of cost and discrimination power

    Design, rationale, and baseline characteristics of a cluster randomized controlled trial of pay for performance for hypertension treatment: study protocol

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    <p>Abstract</p> <p>Background</p> <p>Despite compelling evidence of the benefits of treatment and well-accepted guidelines for treatment, hypertension is controlled in less than one-half of United States citizens.</p> <p>Methods/design</p> <p>This randomized controlled trial tests whether explicit financial incentives promote the translation of guideline-recommended care for hypertension into clinical practice and improve blood pressure (BP) control in the primary care setting. Using constrained randomization, we assigned 12 Veterans Affairs hospital outpatient clinics to four study arms: physician-level incentive; group-level incentive; combination of physician and group incentives; and no incentives (control). All participants at the hospital (cluster) were assigned to the same study arm. We enrolled 83 full-time primary care physicians and 42 non-physician personnel. The intervention consisted of an educational session about guideline-recommended care for hypertension, five audit and feedback reports, and five disbursements of incentive payments. Incentive payments rewarded participants for chart-documented use of guideline-recommended antihypertensive medications, BP control, and appropriate responses to uncontrolled BP during a prior four-month performance period over the 20-month intervention. To identify potential unintended consequences of the incentives, the study team interviewed study participants, as well as non-participant primary care personnel and leadership at study sites. Chart reviews included data collection on quality measures not related to hypertension. To evaluate the persistence of the effect of the incentives, the study design includes a washout period.</p> <p>Discussion</p> <p>We briefly describe the rationale for the interventions being studied, as well as the major design choices. Rigorous research designs such as the one described here are necessary to determine whether performance-based payment arrangements such as financial incentives result in meaningful quality improvements.</p> <p>Trial Registration</p> <p><url>http://www.clinicaltrials.gov</url><a href="http://www.clinicaltrials.gov/ct2/show/NCT00302718">NCT00302718</a></p

    Minimizing the evidence-practice gap – a prospective cohort study incorporating balance training into pulmonary rehabilitation for individuals with chronic obstructive pulmonary disease

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    Background: We have recently demonstrated the efficacy of balance training in addition to Pulmonary Rehabilitation (PR) at improving measures of balance associated with an increased risk of falls in individuals with Chronic Obstructive Pulmonary Disease (COPD). Few knowledge translation (KT) projects have been conducted in rehabilitation settings. The goal of this study was to translate lessons learnt from efficacy studies of balance training into a sustainable clinical service. Methods: Health care professionals (HCPs) responsible for delivering PR were given an hour of instruction on the principles and practical application of balance training and the researchers offered advice regarding; prescription, progression and practical demonstrations during the first week. Balance training was incorporated three times a week into conventional PR programs. Following the program, HCPs participated in a focus group exploring their experiences of delivering balance training alongside PR. Service users completed satisfaction surveys as well as standardized measures of balance control. At six month follow-up, the sustainability of balance training was explored. Results: HCPs considered the training to be effective at improving balance and the support provided by the researchers was viewed as helpful. HCPs identified a number of strategies to facilitate balance training within PR, including; training twice a week, incorporating an interval training program for everyone enrolled in PR, providing visual aids to training and promoting independence by; providing a set program, considering the environment and initiating a home-based exercise program early. Nineteen service users completed the balance training [ten male mean (SD) age 73 (6) y]. Sixteen patients (84 %) enjoyed balance training and reported that it helped them with everyday activities and 18 (95 %) indicated their wish to continue with it. Scores on balance measures improved following PR that included balance training (all p < 0.05). At six month follow-up balance training is being routinely assessed and delivered as part of standardised PR. Conclusions: Implementing balance training into PR programs, with support and training for HCPs, is feasible, effective and sustainable. Trail registration Clinical Trials ID: NCT02080442 (05/03/2014) Electronic supplementary material The online version of this article (doi:10.1186/s12890-015-0067-2) contains supplementary material, which is available to authorized users

    Effectiveness of cricoid pressure in preventing gastric aspiration during rapid sequence intubation in the emergency department: study protocol for a randomised controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Cricoid pressure is considered to be the gold standard means of preventing aspiration of gastric content during Rapid Sequence Intubation (RSI). Its effectiveness has only been demonstrated in cadaveric studies and case reports. No randomised controlled trials comparing the incidence of gastric aspiration following emergent RSI, with or without cricoid pressure, have been performed. If improperly applied, cricoid pressure increases risk to the patient. The clinical significance of aspiration in the emergency department is unknown. This randomised controlled trial aims to; 1. Compare the application of the 'ideal" amount of force (30 - 40 newtons) to standard, unmeasured cricoid pressure and 2. Determine the incidence of clinically defined aspiration syndromes following RSI using a fibrinogen degradation assay previously described.</p> <p>Methods/design</p> <p>212 patients requiring emergency intubation will be randomly allocated to either control (unmeasured cricoid pressure) or intervention groups (30 - 40 newtons cricoid pressure). The primary outcome is the rate of aspiration of gastric contents (determined by pepsin detection in the oropharyngeal/tracheal aspirates or treatment for aspiration pneumonitis up to 28 days post-intubation). Secondary outcomes are; correlation between aspiration and lowest pre-intubation Glasgow Coma Score, the relationship between detection of pepsin in trachea and development of aspiration syndromes, complications associated with intubation and grade of the view on direct largyngoscopy.</p> <p>Discussion</p> <p>The benefits and risks of cricoid pressure application will be scrutinised by comparison of the incidence of aspiration and difficult or failed intubations in each group. The role of cricoid pressure in RSI in the emergency department and the use of a pepsin detection as a predictor of clinical aspiration will be evaluated.</p> <p>Trial registration</p> <p>Australian New Zealand Clinical Trials Registry (ANZCTR): <a href="http://www.anzctr.org.au/ACTRN12611000587909.aspx">ACTRN12611000587909</a></p

    Genetic Analysis of Fin Development in Zebrafish Identifies Furin and Hemicentin1 as Potential Novel Fraser Syndrome Disease Genes

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    Using forward genetics, we have identified the genes mutated in two classes of zebrafish fin mutants. The mutants of the first class are characterized by defects in embryonic fin morphogenesis, which are due to mutations in a Laminin subunit or an Integrin alpha receptor, respectively. The mutants of the second class display characteristic blistering underneath the basement membrane of the fin epidermis. Three of them are due to mutations in zebrafish orthologues of FRAS1, FREM1, or FREM2, large basement membrane protein encoding genes that are mutated in mouse bleb mutants and in human patients suffering from Fraser Syndrome, a rare congenital condition characterized by syndactyly and cryptophthalmos. Fin blistering in a fourth group of zebrafish mutants is caused by mutations in Hemicentin1 (Hmcn1), another large extracellular matrix protein the function of which in vertebrates was hitherto unknown. Our mutant and dose-dependent interaction data suggest a potential involvement of Hmcn1 in Fraser complex-dependent basement membrane anchorage. Furthermore, we present biochemical and genetic data suggesting a role for the proprotein convertase FurinA in zebrafish fin development and cell surface shedding of Fras1 and Frem2, thereby allowing proper localization of the proteins within the basement membrane of forming fins. Finally, we identify the extracellular matrix protein Fibrillin2 as an indispensable interaction partner of Hmcn1. Thus we have defined a series of zebrafish mutants modelling Fraser Syndrome and have identified several implicated novel genes that might help to further elucidate the mechanisms of basement membrane anchorage and of the disease's aetiology. In addition, the novel genes might prove helpful to unravel the molecular nature of thus far unresolved cases of the human disease
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