1,720,972 research outputs found
A glucosylceramide synthase inhibitor prevents the cytotoxic effects of Shiga toxin-2 on human renal tubular epithelial cells
Get PDFShiga toxin-2 binds to the globotriaosyl-ceramide receptor on the plasma membrane of target cells. The highlevel expression of this receptor in renal epithelial cells may account, at least in part, for acute renal failure observed inchildren with hemolytic uremic syndrome. The cytotoxic effect of Shiga toxin-2 was assayed on primary cultures of humanrenal tubular epithelial cells treated with a new specific inhibitor of glucosylceramide synthase (C-9), the ratelimitingfirst step in the glycosphingolipid biosynthetic pathway. The treatment of the cells with 1-5 M C-9 for at least24 h significantly neutralized the action of 1 ng/ml Shiga toxin-2 on cell viability. The expression levels of globotriaosylceramidesignificantly decreased when cells were incubated with 1 M C-9 for 48 h. We propose here that prevention ofglobotriaosyl-ceramide synthesis by the C-9 could be a novel substrate inhibition therapy to neutralize Shiga toxin-2 actionin renal epithelial cells.Fil: Silberstein, Claudia Marcela. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Copeland, Diane P. No especifíca;Fil: Chiang, Wei Lien. No especifíca;Fil: Repetto, Horacio A.. Hospital Nacional Profesor Alejandro Posadas; ArgentinaFil: Ibarra, Cristina Adriana. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin
Epidemiology of Argentinean Shiga Toxin-Producing Escherichia coli
No full textShiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen that can cause nonbloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). HUS, a life-threatening complication that occurs in 5-10% of patients, is characterized by hemolytic anemia, thrombocytopenia, and renal failure. ...Fil: Rivas, Marta. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorio e Instituto de Salud ; ArgentinaFil: Chinen, Isabel. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorio e Instituto de Salud ; ArgentinaFil: Miliwebsky, Elizabeth. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorio e Instituto de Salud ; ArgentinaFil: Galli, Lucía. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorio e Instituto de Salud ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Repetto, Horacio A.. Hospital Nacional Profesor Alejandro Posadas; ArgentinaFil: Masana, Marcelo. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentin
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
Development of an experimental hemolytic uremic syndrome in rats
Get PDFEscherichia coli strains producing Shiga toxins (Stxs) colonize the lower gastrointestinal tract and cause watery diarrhea, hemorrhagic colitis, and hemolytic-uremic syndrome (HUS). HUS is characterized by hemolytic anemia, thrombocytopenia, and acute renal failure. Oliguria associated with acute tubular necrosis and microangiopathic thrombosis has been reported as the most common cause of renal failure in Argentinean children. Our study was undertaken to obtain a model of HUS in rats that was similar to the clinical and renal histopathology findings described in humans. Rats were intraperitoneally inoculated with culture supernatant from recombinant E. coli expressing Stx2. Glomerular filtrate volume evaluated from clearance of creatinine resulted in a progressive reduction (from 53% at 24 h to 90% at 48 h). Urine volume increased significantly at 24 h but returned to normal levels at 48 h. Evidence of thrombocytopenia, anemia and leukocytosis was documented. Macroscopic analysis revealed a hyperemic peritoneal face with intestinal water accumulation. The kidneys were friable and congestive. Histopathological analysis showed glomerular and tubular necrosis as well as microangiopathic thrombosis. Our findings indicated vascular damage and kidney lesions similar to those described in humans with HUS.Fil: Zotta, Elsa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Lago, Néstor Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología; ArgentinaFil: Ochoa, Federico Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Repetto, Horacio A.. Hospital Nacional Profesor Alejandro Posadas; ArgentinaFil: Ibarra, Cristina Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentin
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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