147 research outputs found

    W(h)ither the academy? An exploration of the role of university social work in shaping the future of social work in Europe

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    A controversial proposal to pilot the training of child protection social workers through an intensive work-based route in England is being supported and funded by the UK Government. Frontline, the brainchild of a former teacher, locates social work training within local authorities (‘the agency’) rather than university social work departments (‘the academy’) and has stimulated debate amongst social work academics about their role in shaping the direction of the profession. As a contribution to this debate, this paper explores the duality of social work education, which derives its knowledge from both the academic social sciences and the experience of practice within social work agencies. While social work education has traditionally been delivered by the academy, this paper also explores whether the delivery of training in the allied professions of probation and nursing by ‘the agency’ is equally effective. Finally, this paper explores the Helsinki model which achieves a synergy of ‘academy’ and ‘agency’. It suggests that there are alternative models of social work education, practice and research which avoid dichotomies between the ‘academy’ and the ‘agency’ and enable the profession to be shaped by both social work academics and practitioners

    Magnetic Resonance Imaging of Pulmonary Lesions in Guinea Pigs Infected with Mycobacterium tuberculosis

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    We utilized magnetic resonance imaging to visualize lesions in the lungs of guinea pigs infected by low-dose aerosol exposure to Mycobacterium tuberculosis. Lesions were prominent in such images, and colorized three-dimensional reconstructions of images revealed a very uniform distribution in the lungs. Lesion numbers after 1 month were approximately similar to the aerosol exposure algorithm, suggesting that each was established by a single bacterium. Numbers of lesions in unprotected and vaccinated animals were similar over the first month but increased thereafter in the control animals, indicating secondary lesion development. Whereas lesion sizes increased progressively in control guinea pigs, lesions remained small in BCG-vaccinated animals. A prominent feature of the disease pathology in unprotected animals was rapid and severe lymphadenopathy of the mediastinal lymph node cluster, which is paradoxical given the strong state of cellular immunity at this time. Further development of this technical approach could be very useful in tracking lesion size, number, and progression in the search for new tuberculosis vaccines

    Enhanced priming of adaptive immunity by a proapoptotic mutant of Mycobacterium tuberculosis

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    The inhibition of apoptosis of infected host cells is a well-known but poorly understood function of pathogenic mycobacteria. We show that inactivation of the secA2 gene in Mycobacterium tuberculosis, which encodes a component of a virulence-associated protein secretion system, enhanced the apoptosis of infected macrophages by diminishing secretion of mycobacterial superoxide dismutase. Deletion of secA2 markedly increased priming of antigen-specific CD8+ T cells in vivo, and vaccination of mice and guinea pigs with a secA2 mutant significantly increased resistance to M. tuberculosis challenge compared with standard M. bovis bacille Calmette-Guérin vaccination. Our results define a mechanism for a key immune evasion strategy of M. tuberculosis and provide what we believe to be a novel approach for improving mycobacterial vaccines

    Evidence for Oxidative Stress and Defective Antioxidant Response in Guinea Pigs with Tuberculosis

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    The development of granulomatous inflammation with caseous necrosis is an important but poorly understood manifestation of tuberculosis in humans and some animal models. In this study we measured the byproducts of oxidative stress in granulomatous lesions as well as the systemic antioxidant capacity of BCG vaccinated and non-vaccinated guinea pigs experimentally infected with Mycobacterium tuberculosis. In non-vaccinated guinea pigs, oxidative stress was evident within 2 weeks of infection as measured by a decrease in the serum total antioxidant capacity and blood glutathione levels accompanied by an increase in malondialdehyde, a byproduct of lipid peroxidation, within lesions. Despite a decrease in total and reduced blood glutathione concentrations, there was an increase in lesion glutathione by immunohistochemistry in response to localized oxidative stress. In addition there was an increase in the expression of the host transcription factor nuclear erythroid 2 p45-related factor 2 (Nrf2), which regulates several protein and non-proteins antioxidants, including glutathione. Despite the increase in cytoplasmic expression of Nrf2, immunohistochemical staining revealed a defect in Nrf2 nuclear translocation within granulomatous lesions as well as a decrease in the expression of the Nrf2-regulated antioxidant protein NQO1. Treating M. tuberculosis–infected guinea pigs with the antioxidant drug N-acetyl cysteine (NAC) partially restored blood glutathione concentrations and the serum total antioxidant capacity. Treatment with NAC also decreased spleen bacterial counts, as well as decreased the lung and spleen lesion burden and the severity of lesion necrosis. These data suggest that the progressive oxidative stress during experimental tuberculosis in guinea pigs is due in part to a defect in host antioxidant defenses, which, we show here, can be partially restored with antioxidant treatment. These data suggest that the therapeutic strategies that reduce oxidant-mediated tissue damage may be beneficial as an adjunct therapy in the treatment and prevention of tuberculosis in humans

    Uptake and Accumulation of Oxidized Low-Density Lipoprotein during Mycobacterium tuberculosis Infection in Guinea Pigs

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    The typical host response to infection of humans and some animals by M. tuberculosis is the accumulation of reactive oxygen species generating inflammatory cells into discrete granulomas, which frequently develop central caseous necrosis. In previous studies we showed that infection of immunologically naïve guinea pigs with M. tuberculosis leads to localized and systemic oxidative stress that results in a significant depletion of serum total antioxidant capacity and the accumulation of malondialdehyde, a bi-product of lipid peroxidation. Here we show that in addition, the generation of excessive reactive oxygen species in vivo resulted in the accumulation of oxidized low density lipoproteins (OxLDL) in pulmonary and extrapulmonary granulomas, serum and lung macrophages collected by bronchoalveolar lavage. Macrophages from immunologically naïve guinea pigs infected with M. tuberculosis also had increased surface expression of the type 1 scavenger receptors CD36 and LOX1, which facilitate the uptake of oxidized host macromolecules including OxLDL. Vaccination of guinea pigs with Bacillus Calmette Guerin (BCG) prior to aerosol challenge reduced the bacterial burden as well as the intracellular accumulation of OxLDL and the expression of macrophage CD36 and LOX1. In vitro loading of guinea pig lung macrophages with OxLDL resulted in enhanced replication of bacilli compared to macrophages loaded with non-oxidized LDL. Overall, this study provides additional evidence of oxidative stress in M. tuberculosis infected guinea pigs and the potential role OxLDL laden macrophages have in supporting intracellular bacilli survival and persistence

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Guidance for the treatment and prevention of obstetric-associated venous thromboembolism

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    Potential complications to TB vaccine testing in animal models

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    440-444Testing of new vaccines in animal models has certain advantages and disadvantages. As we better understand the complexity of the immune response to vaccines, new information may be complicating the assessment of the efficacy of new candidate vaccines. Four possible complications are discussed here, (i) induction of Foxp3+ T cells; (ii) induction of memory T cell subsets; (iii) location of extracellular organisms in lung necrosis; and (iv) protection against isolates of high/extreme immunopathology
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