1,720,966 research outputs found
Obstructive intramural coronary amyloidosis: a distinct phenotype of cardiac amyloidosis that can cause acute heart failure.
66-year-old man was admitted to a cardiology unit with diagnosis of congestive heart failure, having complained of worsening asthenia and myalgia for several months before referral. Family history was aspecific. Echocardiography showed a moderately dilated and uniformly hypokinetic left ventricle (end-diastolic diameter 68 mm; ejection fraction 35%); wall thickness was normal. Coronary angiography showed normal epicardial arteries. After temporary improvement during treatment with beta-blockers and ACE-inhibitors, heart failure became severe and left ventricular ejection fraction fell to 20%. Suspected myocarditis prompted a right ventricular endomyocardial biopsy (Panel A), which excluded inflammation but identified amyloid infiltration of small intramural vessels without interstitial involvement. A left ventricular assist device was urgently implanted: histopathological examination of the excised left ventricular apex confirmed obstructive intramural coronary amyloidosis without interstitial deposits and with foci of coagulative necrosis. The patient died a few days later because of gastroenteric haemorrhage (autopsy was not performed) (Panels B–D).
This case documents the existence of isolated intramural coronary obstruction as a peculiar phenotype of cardiac amyloidosis (distinct from the more common amyloidotic cardiomyopathy) (Panels E–I). This rare type of amyloidotic cardiac involvement—which in this patient led to a mistaken clinical diagnosis of myocarditis—must be recognized as one of the possible causes of acute or rapidly progressive heart failure
Immunomorphological and molecular changes in normal epithelium and squamous carcinoma of the vulva
Going Beyond Counting First Authors in Author Co-citation Analysis
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
Electron and immuno-electron microscopy of abdominal fat identifies and characterizes amyloid fibrils in suspected cardiac amyloidosis
We evaluated the role of electron microscopy and immuno-electron microscopy studies on abdominal fat fine-needle biopsy samples in diagnosis and characterization of cardiac amyloidosis. The series consists of 15 patients with echocardiographic evidence of "restrictive cardiomyopathy" suspected to be due to amyloidosis. Patients underwent: clinical examination, electrocardiography, 2-D and Doppler echocardiography, immunofixation of serum and urine for detection of monoclonal immunoglobulins, and abdominalfat biopsies that were investigated with polarized light (Congo red), electron and immuno-electron microscopy using specific antibodies to kappa and lambda light chains, apolipoprotein A1, serum amyloid A (SAA), and transthyretin (TTR). Ultrastructural study of abdominal fat samples identified amyloid deposits in 15/15 cases. Immuno-electron microscopy specifically stained amyloid fibrils with antibodies anti-lambda (n = 8), -kappa (n = 2), -apolipoprotein A1 (n = 2) and -TTR (n = 3). Immuno-electron microscopy revealed TTR immuno-labelling in 2 patients with accidental monoclonal components, and a A reaction in I patient without monoclonal components. TTR and apolipoprotein A1 positive cases carried missense mutations in the corresponding genes. Our results demonstrate that amyloid deposits are present in the abdominalfat of patients suspected to have cardiac amyloidosis and that immuno-electron microscopy was able to characterize the amyloid protein in all cases
Variations on the Author
“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
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
Dispelling the Myths Behind First-author Citation Counts
We 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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