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    Human chitotriosidase: a potential new marker of sarcoidosis severity

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    Sarcoidosis is a multisystemic granulomatous disorder of unknown etiology. The unpredictable clinical course of the disease has prompted research into biomarkers useful for predicting outcome. Among the potential markers of sarcoidosis, a recently proposed indicator was chitotriosidase, a chitinase produced by activated macrophages. Chitotriosidase is involved in the defense against pathogens containing chitin. Increased concentrations of chitotriosidase have been observed in a number of lysosomal storage diseases including Gaucher disease and more recently also in sarcoidosis. In 2004, significantly higher serum chitotriosidase activity was reported for the first time in sarcoidosis patients with respect to controls (p < 0.01); a similar increase was subsequently observed in bronchoalveolar lavage of these patients. In 2007, an increase in enzyme activity was described in juvenile sarcoidosis. Chitotriosidase activity was found to be correlated with angiotensin-converting enzyme levels in serum, radiological stages and quantitative high-resonance CT score for sarcoidosis, suggesting that this enzyme could be a potential marker of disease severity worthy of further study. To evaluate the sensitivity and specificity of this marker, further analysis was done in other granulomatous and diffuse lung diseases. Here, we review the principal literature and the recent evidence of chitotriosidase as a possible marker of sarcoidosis

    Human Chitotriosidase: a sensitive biomarker of sarcoidosis

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    Background Sarcoidosis is a multisystem granulomatous disease of unknown etiology. No suitable biomarkers are available to evaluate the evolution of this disease, which still has an unpredictable clinical course. Some years ago our research group proposed chitotriosidase as a potential biomarker with prognostic value, that however needed to be validated. Aims and methods The aims of this study were to evaluate the sensitivity and specificity of chitotriosidase in a population of 232 sarcoidosis patients under the observation of our Sarcoidosis Regional Referral Centre in Siena and to analyse enzyme concentrations in different disease phenotypes (as defined by the recently published COS classification) to define its prognostic value. Results Serum chitotriosidase concentrations were significantly higher in patients than in healthy controls (p&lt;0.0001) and were directly correlated with ACE levels (r=0.25, p&lt;0.0001). ROC curve analysis revealed 88.6 % sensitivity and 92.8 % specificity. Enzyme concentrations were significantly higher in stage 3 sarcoidosis than in stage 0 (p=0.02). The lowest concentrations of chitotriosidase were found in untreated patients in remission (COS-1), while the highest enzyme concentrations were found in symptomatic patients with persistent disease on steroids and with functional deterioration in the last year (COS-9). In COS-9 subgroup, chitotriosidase decreased significantly after the increasing of steroid dose or the introduction of a new immunosuppressant therapy (p&lt;0.01). Conclusion Chitotriosidase proved to be a biomarker with good sensitivity and specificity that is easily detected in serum. It can be proposed in clinical practice to identify progressive patients requiring close follow-up, to detect relapses and to evaluate the effects of therap

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    Assessment of cardiac involvement in sarcoidosis by echocardiography

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    The main objective of this study is to determine the prevalence of left ventricular systolic and diastolic dysfunction in patients with chronic sarcoidosis without clinical evidence of heart disease. The study includes 69 chronic sarcoidosis patients, 30 diagnosed by organ biopsy and 39 by clinical history, chest X-ray, high resolution computerized tomography (HRCT) and bronchoalveolar lavage (BAL), without suspected cardiac involvement. The control group consisted of 26 subjects selected from a population of hospital workers. The examination includes 12-lead ECG and echocardiographic examination. The results show that there were no differences in atrial size, left ventricular diameters, wall thickness, left ventricular ejection fraction or endocardial fractional shortening between the sarcoid group and controls. Signs of diastolic dysfunction were found in 33 (55%) patients, however, this group was significantly older than the others and had marginally higher blood pressure. Sarcoid patients had lower midwall fractional shortening (mFS) than controls; patients with diastolic dysfunction also had lower mFS but the difference was not significant. In conclusion, the results demonstrated an absence of left ventricular systolic dysfunction, evaluated by traditional echocardiographic methods, in our chronic sarcoidosis patients and an apparent absence of any relation between left ventricular diastolic dysfunction and sarcoidosis. Lower mFS was found among patients, particularly those with a long history of sarcoidosis. Further analysis is required to evaluate the significance of this index as a potential marker of heart involvement in chronic sarcoidosis

    Chitotriosidase: a sensitive biomarker of sarcoidosis

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    Chitotriosidase is a member of family of glycosylhydrolases, enzymes involved in the degradation of chitin and chitin-like substrate, identified in a wide variety of organisms. Increased concentrations of chitotriosidase have been reported in several lysosomal storage diseases and more recently also in sarcoidosis. In this study chitotriosidase concentrations were evaluated in a population of 233 sarcoidosis patients and 70 controls in order to verify enzyme specificity and sensibility and to evaluate chitotriosidase prognostic meaning. Chitotriosidase has been found significantly increased in serum of patients with sarcoidosis than in controls (p&lt; 0.0001). ROC curve analysis revealed: cut-off value of 39.50 nmol/h/ml, sensitivity 89,70% and specifity 90%. The analysis of chitotriosidase in different phenotypic subgroups of patients revealed very high serum enzyme levels in symptomatic patients requiring systemic steroid therapy at onset and after disease relapses. In conclusion as a new potential biomarker of sarcoidosis severity, chitotriosidase resulted sensitive, reproducible and easily detectable in serum

    Variations on the Author

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    “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

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    We 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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