1,720,994 research outputs found
Myocardialcontraction bands. Definition, quantification and significance in forensicpathology.
No full textAltered distribution of desmin filaments in hypertrophic cardiomyopathy: an immunohistochemical study.
No full textHypertrophic cardiomyopathy (HCM) is characterized by myofiber hypertrophy and disarray. Intermediate filaments play an important role in maintaining of normal cell shape. Desmin filaments have been detected in adult cardiomyocytes, and vimentin and keratin filaments in cardiomyocytes during embryonic development. The pattern of arrangement of intermediate filaments in HCM has not been reported. We examined the distribution of intermediate filaments in formalin-fixed tissue sections of the disarrayed myofibers from 10 hearts with HCM using an immunohistochemical technique and antibodies to desmin, vimentin, and high and low molecular weight keratins. The controls consisted of subaortic tissue from surgically explanted hearts of patients with ischemic heart disease. In the ischemic hearts, desmin was detected in the Z bands and intercalated disks. In all HCM cases, three patterns of staining for desmin were noted: (a) individual myocytes showing a parallel arrangement along Z bands; (b) focal myofibers with decreased or complete loss of labeling of Z bands; and (c) individual myocytes with intense granular cytoplasmic staining especially in disarrayed myofibers. No staining for vimentin or keratins was noted in the cardiomyocytes from either the HCM or ischemic cases. The altered arrangement of desmin filaments in the disarrayed cardiac muscle fibers may play a role in the altered contractility that occurs in patients with HCM
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
Frequency and extent of contraction band necrosis in orthotopically transplanted human hearts. A morphometric study
No full textType andextent of myocardial injury related to brain damage and its significance in hearttransplantation: a morphometric study.
No full textAsystematic study of a myocardial lesion: colliquative myocytolysis
No full textBackground: The term bmyocytolysisQ was first used to define the repair process of contraction band necrosis associated with an acute myocardial infarction. On the other hand, in the latter condition a bmyofibrillolysis,Q presenting edematous myocardial cells not involved by infarct necrosis, and without evidence of repair process was reported. The objective of this study is to establish the frequency, extent and meaning of this myocardial lesion.
Materials and methods: In 12 groups of patients for a total of 432 cases with and without coronary heart disease, bcolliquative myocytolysisQ – i.e., progressive vacuolization by loss of myofibrils until their total or subtotal disappearance associated with intramyocellular edema in absence of any cellular reaction – was graded in 16 histological slides of the different cardiac regions in each pathological case.
Results: Colliquative myocytolysis (CM) was present in more than 90% with a maximal extent in cases of irreversible congestive heart failure followed by transplanted heart cases (67%) with a survival greater than 1 week. In all other groups, the lesion was absent or minimal. Conclusions: No correlation was found between CM and contraction band necrosis, gender, age, heart weight, myocardial fibrosis, coronary artery stenosis, clinical data. Colliquative myocytolysis is a specific histological marker of congestive heart failure, without relation to coronary blood flow, heart weight and myocardial fibrosis. Vacuolization of myocardial cells may be due to other causes (e.g., storage disease, etc.) or may be an artifact. There is no support for the belief that coronary ischemia or myocardial hypoxia is its causes
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