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The potential danger of a solely interferon-gamma release assay-based approach to testing for latent Mycobacterium tuberculosis infection in children
No full textTuberculous dactylitis - an easily missed diagnosis
Full text linkThe prevalence of tuberculosis (TB) continues to rise worldwide. Current migration patterns and increased travel to high-prevalence TB countries will result in more frequent presentations of less common forms of TB. Tuberculous dactylitis, a form of tuberculous osteomyelitis, is well recognised in countries with a high prevalence of TB. We provide a systematic review of all published cases of tuberculous dactylitis in children and adolescents and describe a case to illustrate the typical features of the disease. Our review revealed 37 cases of tuberculous dactylitis in children and adolescents, all reported in the last 17 years. Children less than 10 years of age are most frequently affected and the hand is the most commonly affected site. Concurrent pulmonary TB is present in a fifth of cases and systemic symptoms are usually absent. Positive TST and IGRA support the presumptive diagnosis, but cannot be used as rule-out tests. The definitive diagnosis relies on the detection M. tuberculosis by PCR or culture. Treatment should comprise of a standard three to four drug anti-tuberculous regimen. The optimal treatment duration remains unknown. Surgery has a limited role in the treatment in general but may play a supportive role, and curettage of the cavity has been recommended for avascular lesion
Absence of interferon-gamma release assay conversion following tuberculin skin testing
No full textBackground: The tuberculin skin test (TST) has been the established screening method for tuberculosis (TB) for over a century. Interferon-gamma release assays (IGRAs) using Mycobacterium tuberculosis-specific antigens are increasingly used as diagnostic tests for TB. Tuberculin comprises multiple antigens, including the antigens used in the QuantiFERON®-TB Gold In-Tube (QFT-GIT) assay. Exposure to these antigens by means of a TST may prime an immune response that leads to a false-positive result in a subsequent IGRA, limiting the validity of IGRAs in patients in whom these tests are performed sequentially. The current data on the influence of prior TST on IGRAs show inconsistent results.Methods: Sixteen non-bacille Calmette-Guérin immunised medical students with no history of TB exposure and minimal risk of exposure to TB during the study period were tested simultaneously with a TST and QFT-GIT. The QFT-GIT assay was repeated 6 and 10 weeks later.Results: At baseline, all TST and QFT-GIT results were negative and remained negative 6 and 10 weeks after the TST.Conclusion: These data show that negative QFT-GIT results are reproducible and suggest that a TST does not result in conversion of subsequent QFT-GIT assays in the absence of concomitant TB exposure. Therefore, a positive QFT-GIT should not be attributed to boosting induced by a previous TST
To x-ray or not to x-ray? Screening asymptomatic children for pulmonary TB:a retrospective audit
No full text<p>Objective Recent studies found that a chest x-ray (CXR) has limited value in the assessment of asymptomatic adults with tuberculosis (TB) infection. We aimed to determine in asymptomatic children with a positive tuberculin skin test and/or interferon-.release assay (TST/IGRA) whether a CXR identifies findings suggestive of pulmonary TB.</p><p>Design, setting and patients All children with TB infection (defined as TST >= 10 mm and/or positive IGRA) presenting to The Royal Children's Hospital Melbourne during a 54-month period were included. All CXRs were reviewed by a senior radiologist blinded to the clinical details. The medical records of those with radiological abnormalities suggestive of TB were examined to identify those who were asymptomatic when the CXR was done. Demographical data were also collected.</p><p>Results CXRs were available for 268 of 330 TB-infected children, of whom 60 had CXR findings suggestive of TB. Of the 57 for whom clinical details were available, 26 were asymptomatic. Of these asymptomatic children with radiological abnormalities suggestive of TB, 6 had CXR findings suggestive of active TB, 14 had CXR findings suggestive of prior TB and 6 had isolated non-calcified hilar lymphadenopathy. The six with findings suggestive of active TB represented 2.6% (95% CI 0.9 to 5.5%) of asymptomatic TST/IGRApositive children with evaluable CXRs. One child with isolated hilar lymphadenopathy had microbiologicallyconfirmed TB.</p><p>Conclusions In contrast to the results from studies in adults, a CXR identified a small but noteworthy number of children with findings suggestive of pulmonary TB in the absence of clinical symptoms.</p>
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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