1,721,007 research outputs found
Myocarditis: when to suspect and how to diagnose it in athletes
No full textMyocarditis should be suspected in athletes with unexplained cardiac arrhythmias and dysfunction, especially if preceded by a flu-like syndrome. An early diagnosis is desirable in order to avoid the risk of fatal consequences, since physical activity can enhance the inflammatory process. Although several diagnostic tools can be useful for the diagnosis of myocarditis, endomyocardial biopsy is still the gold standard. Athletes with myocarditis should be withdrawn from all competitive sports for at least 6 months and resume training when ventricular function and cardiac dimensions return to normal and the clinically relevant arrhythmias disappear. In the presence of life-threatening arrhythmias or rapidly progressive cardiac dysfunction an antiviral or an immunosuppressive treatment should be considered depending on whether a viral agent is present or absent, respectively, in the myocardium. J Cardiovasc Med 7:301-306 (C) 2006 Italian Federation of Cardiology
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
Increased brain natriuretic peptide secretion is a marker of disease progression in nonobstructive hypertrophic cardiomyopathy.
No full textBACKGROUND: Hypertrophic cardiomyopathy (HCM) is associated with increased plasma brain natriuretic peptide (BNP), but sequential plasma and myocardial BNP assessment in stable and dilated HCM has never been performed. METHODS AND RESULTS: Forty consecutive HCM patients (42 +/- 8 years, 25 males) underwent cardiac catheterization, angiography, and left ventricular (LV) endomyocardial biopsy. During follow-up (70.5 +/- 6.7 months), 30 patients (Group 1) remained stable whereas 10 patients (Group 2) progressed to dilated phase. Group 2 patients underwent a second invasive study with LV biopsy. BNP plasma levels were measured at baseline and at follow-up in all patients. All biopsies were processed for histology and immunohistochemistry with anti-BNP antibodies. BNP plasma levels remained unchanged in Group 1, whereas it significantly increased in all Group 2 patients who exhibited an elevation of LV and right ventricular end-diastolic pressure. Immunohistochemistry showed an increase of BNP-positive myocytes in follow-up biopsies when compared with baseline (75.0 +/- 15.0 % versus 29.8 +/- 10.0 %; P = .005) with a significant correlation with LV end-diastolic pressure (r = 0.78, P < .001) and plasma BNP (r = 0.83, P < .001). CONCLUSIONS: Progression to end-stage of HCM is characterized by further increase of myocardial and plasma BNP. Serial assessment of plasma BNP may provide noninvasive recognition of hemodynamic deterioration, allowing prompt institution of heart failure therapy
Tissue Doppler imaging in Fabry disease
No full textPURPOSE OF REVIEW: The development of effective enzyme replacement/enhancement therapy makes of clinical relevance considering Fabry disease in the differential diagnosis of patients with hypertrophic cardiomyopathy. In particular the opportunity to significantly modify the clinical progression of the disease has reinforced the need for early diagnosis of Fabry cardiomyopathy. RECENT FINDINGS: The study with tissue Doppler of Fabry patients with endomyocardial biopsy-proven cardiac involvement showed a reduction of both diastolic and systolic myocardial velocities recorded at septal and lateral corners of mitral annulus. Tissue Doppler abnormalities were present not only in patients with left ventricular hypertrophy but also in younger patients with normal cardiac wall thickness and represent the first sign of myocardial damage. Furthermore tissue Doppler studies have been shown useful in detecting cardiac involvement in female carriers with no systemic manifestations of Fabry disease. In patients already submitted to enzyme-replacement therapy tissue Doppler and strain rate imaging represent useful noninvasive tools in assessing treatment efficacy. SUMMARY: Tissue Doppler imaging can provide early detection of cardiac involvement in Fabry disease and represents the most accurate and sensitive noninvasive tool for the diagnosis of myocardial dysfunction and for the assessment of cardiac improvement during enzyme replacement therapy. The detection of tissue Doppler abnormalities in female carriers may represent a hint for an invasive assessment of cardiac involvement
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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