1,721,058 research outputs found
Immunopathological aspects of immunoglobulin A nephropathy and other mesangial proliferative glomerulonephritides
No full textPrimary IgA nephropathy: the relevance of experimental models in the understanding of human disease
No full textThe relevance of experimental models in the pathogenetic investigation of primary IgA nephropathy
No full text
Successful treatment of a facial attack of angioedema with icatibant in a patient with idiopathic angioedema.
No full textAngioedema (AE) is related to the activation of the contact phase system—kallikrein and generation of bradykinin. Different types of AE are recognized: hereditary or acquired deficit of the C1 inhibitor, drug-related, or idiopathic. Treatment of idiopathic nonhistaminergic AE (IAE) is difficult because corticosteroids, antihistamine drugs, and adrenalin are inefficacious. We describe a patient with an IAE and an acute attack of facial AE that was successfully treated with the bradykinin receptor antagonist icatibant. This case report strengthens the relevance of bradykinin formation in IAE and underlines the effectiveness of icatibant as a therapeutic option in acute IAE. Angioedema (AE) is characterized by recurrent attacks of nonpruritic swelling of subcutaneous and submucosal tissues not associated to urticaria. The pathogenesis of AE is linked to an activation of the contact phase system—kallikrein, which leads to the ultimate generation of bradykinin as the main vasopermeabilizing substance [1]. Different clinical forms of AE are recognized: paradigmatic is hereditary AE (HAE), due to a congenic defect of the complement C1 inhibitor (C1 inh) with an autosomal transmission. In type I HAE, antigenic and functional levels of C1 inh are less than 50% of normal values. Less commonly, there is a dysfunctional C1 inh protein with normal antigenic levels but reduced activity on C1 esterase (HAE type II). Angioedema with a typical appearance of recurrent attacks of dermis and mucosae may occur late in life as an acquired condition, with reduced antigenic and functional C1 inh. Acquired AE is associated to malignancies or lymphoproliferative disorders, monoclonal gammopathies, or other conditions [2]. Angioedema may also represent adverse effects of drugs such as angiotensin-converting enzyme inhibitors, estrogens, or nonsteroidal anti-inflammatory drug. In this latter case, levels of C1 inh are generally not altered or only minimally affected. Finally, in some patients, the occurrence of AE attacks with a clinical onset after the third to fourth decade of life is not associated to C1 inh alteration and absence of other clinical accompanying conditions or drugs (idiopathic AE [IAE]). Bradykinin seems also to play a relevant pathogenic role in IAE. For treatment of AE, corticosteroids, epinephrine, and antihistamine drugs are ineffective, whereas concentrate of plasma-derived C1 inh has long been proved efficacious. Recently, a specific bradykinin B2 receptor antagonist, icatibant, has been introduced for the treatment of HAE attacks [3]. Perhaps, although plasma-derived C1 inh concentrate is very effective in those conditions characterized by reduced or dysfunctional C1 inh such as HAE and acquired AE, it is completely inefficacious in those conditions with normal levels of C1 inh, such as angiotensin-converting enzyme inhibitor–related AE or IAE. Although some beneficial effects have been reported with tranexamic acid in preventing attacks of IAE, at the moment, there is not specific therapy for this disabling condition. We report a case of the successful treatment of a facial AE attack in a patient with IAE. The patient, a 50-year-old white man, complained of the recent appearance of recurrent attacks of AE, involving mainly the facial region. The attacks started about 1 year before, without any precipitating condition and with an increasing frequency reaching 2 to 3 attacks per month. Angioedema attacks were nonpruritic, not associated to urticaria, lasted about 36 hours, and resolved spontaneously. Antihistamine drugs and corticosteroids were almost completely ineffective. The patient was also prescribed a prophylactic dose of levocetirizin (5 mg twice a day) for about a month without any beneficial effect on frequency and severity of AE attacks. Physical examination did not show any relevant sign. Laboratory investigation showed normal levels of C1 inh, C3 and C4, inflammatory markers, autoimmunity, and immunoglobulins (Table). The skin prick test for common inhalants and foods gave negative response while specific immunoglobulin E for foods was in the reference range
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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