1,720,995 research outputs found
Infection and inflammation in the cardiovascular system.
Get PDFInfection and inflammation of the cardiovascular system are a frequent cause of cardiac and/or vascular disease, which represents an enormous clinical burden in adult medicine. Major advances have now occurred in understanding cellular and molecular bases of a wide variety of inflammatory cardiovascular diseases. Some of these (myocarditis) have been recognized as inflammatory disease for a long time. Of others (atherosclerosis), the inflammatory nature of disease and possible involvement of bacterial antigens therein has emerged only recently. In both cases however, new insights in inflammatory mechanisms will have great impact on clinical thinking and management
T-Cell Mediated Inflammatory Activity in the Stellate Ganglia of Patients with Ion Channel Disease and Severe Ventricular Arrhythmias.
No full textBACKGROUND:
-Long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) are electrical diseases characterized by catecholamine-induced ventricular arrhythmias. Unbalanced autonomic innervation of the heart may trigger arrhythmic events and stellectomy is a treatment option for patients who are resistant to pharmacological drugs. We analysed left stellectomy specimens of LQTS and CPVT patients for signs of inflammatory activity.
METHODS AND RESULTS:
-Stellate ganglia were retrieved from 12 consecutive patients (8F, 4M, mean age 23.4±17 yrs) with either LQTS (n=8) or CVPT (n=4) and serious arrhythmias. Control stellate ganglia were obtained from 10 accidently deceased patients (6F, 4M, mean age 35±17.6 yrs). Sections were immunostained with antibodies against T cells (CD3, CD4, CD8, CD20, Granzyme B), CD68 (macrophages) and HLA-DR antigens (activation marker). Immunopositive cells were quantified as cells/mm2. PCR and RT-PCR were performed to screen for herpes virus DNA. Stellate ganglia of all 12 LQTS/CVPT patients revealed mild but distinct inflammatory infiltrates composed of T-lymphocytes and macrophages, which were diffusely spread, but also clustered in small foci apposed to ganglion cells, interpreted as T cell-mediated ganglionitis. Morphometrical analysis showed that CD3+ and CD8+ T cells/mm2 were significantly higher in the ganglia of LQTS/CVPT cases than in healthy controls (p=0.0018 and p=0.0009, respectively). Molecular analyses were negative for neurotropic viruses.
CONCLUSIONS:
-T-cell mediated cytotoxicity towards ganglion cells may boost adrenergic activity as to trigger or enhance electrical instability in LQTS/CVPT patients who are already genetically predisposed to arrhythmias
Intraplaque hemorrhage in cardiac allograft vasculopathy.
No full textPlaque hemorrhage, inflammation and microvessel density are key determinants of plaque vulnerability in native coronary atherosclerosis (ATS). This study investigates the role of intraplaque hemorrhage (IPH) and its relation with inflammation and microvessels in cardiac allograft vasculopathy (CAV) in posttransplanted patients. Seventy coronary plaques were obtained from 12 patients who died because of CAV. For each patient we collected both native heart and the allograft, at the time of transplantation and autopsy, respectively. Intralesion inflammation, microvessels and IPH were assessed semi-quantitatively. IPH was observed in 21/35 (60%) CAV lesions and in 8/35 (22.9%) native ATS plaques, with a strong association between fibrocellular lesions and IPH (p = 0.0142). Microvessels were detected in 26/35 (74.3%) of CAV lesions with perivascular leakage as sign of endothelial damage in 18/26 (69.2%). IPH was strongly associated with microvessels (p < 0.0001). Inflammation was present in 31/35 (88.6%) of CAV lesions. CAV IPH+ lesions were characterized by presence of both fresh and old hemorrhage in 12/21 (57.1%). IPH, associated with microvessel damage and inflammation, is an important feature of CAV. Fresh and old intralesion hemorrhage suggests ongoing remodeling processes promoting the lesion progression and vulnerability
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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