41 research outputs found

    Depletion of embryonic macrophages leads to a reduction in Angiogenesis in the Ex OVO chick Chorioallantoic membrane assay

    Get PDF
    Macrophages play an important but poorly understood role in angiogenesis. To investigate their role in vessel formation, relevant in vivo models are crucial. Although the chick chorioallantoic membrane (CAM) model has been frequently used as an angiogenesis assay, limited data are available on the involvement of chicken macrophages in this process. Here, we describe a method to deplete macrophages in the ex ovo chick CAM assay by injection of clodronate liposomes and show that this depletion directly affects vascularisation of collagen onplants. Chicken embryos were injected intravenously with either clodronate or phosphate-buffered saline (PBS) liposomes, followed by placement of collagen type I plugs on the CAM to quantify angiogenic ingrowth. Clodronate liposome injection led to a significant 3.4-fold reduction of macrophages compared with control embryos as measured by immunohistochemistry and flow cytometry. Furthermore, analysis of vessel ingrowth into the collagen plugs revealed a significantly lower angiogenic response in macrophage-depleted embryos compared with control embryos, indicating that chicken embryonic macrophages play an essential function in the development of blood vessels. These results demonstrate that the chick CAM assay provides a promising model to investigate the role of macrophages in angiogenesis

    Physical Activity After Surgery for Severe Obesity: The Role of Exercise Cognitions

    Get PDF
    # The Author(s) 2010. This article is published with open access at Springerlink.com Background Physical activity after bariatric surgery is associated with sustained weight loss and improved quality of life. Some bariatric patients engage insufficiently in physical activity. This may be due to exercise cognitions, i.e., specific beliefs about benefits of and barriers to physical exercise. The aim of this study was to examine whether and to what extent both physical activity and exercise cognitions changed at 1 and 2 years post-surgery and whether exercise cognitions predict physical activity. Methods Forty-two bariatric patients (38 women, 4 men; mean age 38±8 years, mean body mass index prior to surgery 47±6 kg/m 2) filled out self-report instruments to examine physical activity and exercise cognitions pre- and post-surgery

    Erratum to: Methods for evaluating medical tests and biomarkers

    Get PDF
    [This corrects the article DOI: 10.1186/s41512-016-0001-y.]

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

    Get PDF
    Meeting abstrac

    Evidence synthesis to inform model-based cost-effectiveness evaluations of diagnostic tests: a methodological systematic review of health technology assessments

    Get PDF
    Background: Evaluations of diagnostic tests are challenging because of the indirect nature of their impact on patient outcomes. Model-based health economic evaluations of tests allow different types of evidence from various sources to be incorporated and enable cost-effectiveness estimates to be made beyond the duration of available study data. To parameterize a health-economic model fully, all the ways a test impacts on patient health must be quantified, including but not limited to diagnostic test accuracy. Methods: We assessed all UK NIHR HTA reports published May 2009-July 2015. Reports were included if they evaluated a diagnostic test, included a model-based health economic evaluation and included a systematic review and meta-analysis of test accuracy. From each eligible report we extracted information on the following topics: 1) what evidence aside from test accuracy was searched for and synthesised, 2) which methods were used to synthesise test accuracy evidence and how did the results inform the economic model, 3) how/whether threshold effects were explored, 4) how the potential dependency between multiple tests in a pathway was accounted for, and 5) for evaluations of tests targeted at the primary care setting, how evidence from differing healthcare settings was incorporated. Results: The bivariate or HSROC model was implemented in 20/22 reports that met all inclusion criteria. Test accuracy data for health economic modelling was obtained from meta-analyses completely in four reports, partially in fourteen reports and not at all in four reports. Only 2/7 reports that used a quantitative test gave clear threshold recommendations. All 22 reports explored the effect of uncertainty in accuracy parameters but most of those that used multiple tests did not allow for dependence between test results. 7/22 tests were potentially suitable for primary care but the majority found limited evidence on test accuracy in primary care settings. Conclusions: The uptake of appropriate meta-analysis methods for synthesising evidence on diagnostic test accuracy in UK NIHR HTAs has improved in recent years. Future research should focus on other evidence requirements for cost-effectiveness assessment, threshold effects for quantitative tests and the impact of multiple diagnostic tests

    Erratum to: Methods for evaluating medical tests and biomarkers

    Get PDF
    [This corrects the article DOI: 10.1186/s41512-016-0001-y.]

    Overgewicht: energiebeperkt dieet of laag-koolhydraten dieet?

    No full text
    Is een laag-koolhydratendieet effectiever dan een energiebeperkt dieet bij de behandeling van overgewicht? Welke veranderingen in lichaamssamenstelling, kwaliteit van leven en type eetgedrag zijn er na acht weken te meten

    Primary student teachers’ professional identity tensions: The construction and psychometric quality of the professional identity tensions scale

    Get PDF
    This research aims to develop and validate an instrument for measuring primary student teachers’ professional identity tensions. Based on dissonance theory, we transformed existing vignettes (Pillen et al., 2013) into to a quantitative Professional Identity Tensions Scale (PITS) and added tensions regarding teaching in urban contexts. We examined the psychometric quality of the PITS by administering this scale to primary student teachers from teacher education institutions in urban areas across the Netherlands. Two studies were conducted in the process of validating the PITS. First, items were tested among a sample of 211 students to explore whether they measure underlying constructs of professional identity tensions. Second, retained items were administered to a new sample of 271 students. Confirmatory factor analysis demonstrated a similar factor structure. The final instrument includes 34 items rated on a 5-point Likert scale measuring nine different professional identity tensions. Implications for future research and practice are discussed

    Domains of teacher identity: A review of quantitative measurement instruments

    Get PDF
    This study provides an overview of components of teacher identity that are found in quantitative measurement instruments; and reports on the psychometric quality of these measurement instruments. Our search included studies that assessed components of teacher identity published in English-written, peer-reviewed articles between 2000 and 2018. We analyzed a total of 59 components in 20 studies. After we categorized the components on the basis of a substantive analysis, six main domains of teacher identity became apparent: Self-image, Motivation, Commitment, Self-efficacy, Task perception, and Job satisfaction. Whereas the overall psychometric properties of the measurement instruments used in the different studies were acceptable to good, our systematic overview revealed several conceptual and methodological issues that need to be resolved. The results may contribute to the further operationalization of the complex construct of teacher identity
    corecore