1,720,980 research outputs found
Heart- and skeletal muscle-specific antigens recognized by trichinellosis patient sera
No full textThe heart can be seriously affected in human trichinellosis, and cardiac involvement can cause death. Experimental infections in rats have suggested the possible participation of immunopathological processes. The aim of the present paper was to investigate the possible presence in trichinellosis patient sera of antibodies recognizing host tissues and particularly the myocardium. Nineteen sera from late period trichinellosis patients, who acquired infection in the Poznan region (Poland), were tested by immunoblot on extracts from normal rat or human heart ventricle wall, spleen, placenta, kidney and skeletal muscle. Patients' sera recognized several antigens that were not recognized by normal sera. On rat and human heart ventricle wall, a high proportion of sera (42%) reacted with a protein of 68 kDa (P < 0.05 compared to normal sera). The reactivity with this antigen, however, was not significantly different in patients with or without cardiac involvement. When sera were tested on skeletal muscle we found that 47% reacted with a protein of 27 kDa and 53% reacted with a protein of 41 kDa (P < 0.05 for both proteins, compared with normal sera). The reactivity against the 68 kDa antigen and against the 27 and 41 kDa skeletal muscle antigens was not observed on kidney, placenta and spleen extracts. Moreover, very few bands were observed on these tissues as compared to heart and skeletal muscle tissues, thus suggesting a high tissue specificity of the reactivity of trichinellosis sera. In conclusion, this study identifies organ-specific autoantibodies in trichinellosis patient sera, their role in the pathogenesis of cardiac involvement being still unclear
Use of human chondrocyte cell cultures to identify and characterize reactive antibodies in rheumatoid arthritis sera
No full textOBJECTIVE:
To study the reactivity of rheumatoid arthritis (RA) sera with human chondrocyte populations isolated from normal cartilage and expanded in vitro.
METHODS:
Human articular chondrocytes were cultured as adherent (non-differentiated) cells on plastic dishes or in suspension (differentiated) on dishes previously coated with a thin layer of 1% agarose. Sera from 28 RA patients and 5 paired synovial fluids were tested on lysates from chondrocytes and fibroblasts as control by immunoblot. Antigen expression on the cell membrane was evaluated by flow cytometry in a few sera.
RESULTS:
In 9/28 RA sera IgG antibodies specific for chondrocyte antigens (97 kDa, 74 kDa, 67 kDa, 60 kDa, 54 kDa, 48 kDa and 37 kDa) were detected. Twelve sera reacted with proteins expressed both on chondrocytes and fibroblasts and 7 with fibroblasts only; two sera had no reactivity. When lysates from adherent or suspension chondrocytes were compared, RA sera reacted with higher intensity and detected more antigens on chondrocytes cultured in suspension. Flow cytometry assay demonstrated that RA sera are able to recognize antigens expressed on the cell membrane of the human chondrocytes.
CONCLUSION:
Our data indicate that: a) 32% of the RA sera contain antibodies reactive with antigens expressed exclusively by chondrocytes, but this value rises to 75% if antigens expressed both by chondrocytes and fibroblasts are considered; b) the reactivity of fully differentiated chondrocytes in suspension culture is higher than the reactivity of chondrocytes cultured in monolayer; and c) some of the chondrocyte-specific antigens identified are associated with the chondrocyte membrane. Thus, in vitro cultured chondrocytes may be used to study both the specificity and the biological activity of autoantibodies in RA
Use of human chondrocyte cell cultures to identify and characterize reactive antibodies in rheumatoid arthritis sera.
No full textUse of human chondrocyte cell cultures to identify and characterize reactive antibodies in rheumatoid arthritis sera.
No full text
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
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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