1,721,002 research outputs found
Liposome-mediated increase of the superoxide dismutase content in human erythrocytes: characterization by electron spin resonance
No full textRoom temperature electron spin resonance (ESR) spectroscopy, together with enzyme activity measurements, have been used to study the liposome-mediated enrichment of human red blood cells with superoxide dismutase. The ESR technique was found to be useful not only for qualitative and quantitative determinations, but also for demonstration of enzyme activity inside intact cells. The molecular properties of superoxide dismutase in relation to pharmacological and biotechnological applications are reviewed
Copper-containing amine oxidase purified from lathyrus sativus as a modulator of human neutrophil functions
No full textOver the last few decades, copper-containing amine oxidase (Cu-AO) from vegetal sources, and belonging to the class of diamine oxidase, has been documented to exhibit beneficial effects in both in vivo and ex vivo animal models of inflammatory or allergic conditions, including asthma-like reaction and myocardial or intestinal ischemia-reperfusion injuries. The aim of the present study was to assess the potential of vegetal Cu-AO as an anti-inflammatory and an antiallergic agent and to clarify its antioxidant properties. In cell-free systems, the reactive oxygen species and reactive nitrogen species scavenging properties of Cu-AO that is purified from Lathyrus sativus were investigated. Its effect on the formyl-methionyl-leucyl-phenylalanine peptide (fMLP)-activated cellular functions of human neutrophils were subsequently analyzed. The obtained results demonstrated that Cu-AO is not a scavenger of superoxide or nitric oxide, and does not decompose hydrogen peroxide. However, it inhibits the fMLP-dependent superoxide generation, elastase release and cell migration, and interferes with the process of calcium flux, supporting the idea that plant Cu-AO can interact with human neutrophils to modulate their inflammatory function. Therefore, the importance of these properties on the possible use of vegetal Cu-AO to control inflammatory conditions, particularly intestinal inflammation, is discussed in the current study
Production of hydrogen peroxide by human red blood cells exposed to anthracycline antibiotic daunomycin
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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
Generation of daunomycin radicals on the outer side of the erythrocyte membrane
No full textThe generation of the daunomycin semiquinone was studied in intact red blood cells under CO atmosphere by ESR spectroscopy. The undialyzed hemolysates and the spin broadening agent chromium oxalate quenched the ESR signal, suggesting external location of the ESR-detectable radicals and their slow diffusion inside. A constant outward flow of O2− was detected by monitoring the approach to the steady state of the ESR signal of Cu,Zn superoxide dismutase externally added to red blood cells plus daunomycin in air. This suggests a reductase on the outer side of the erythrocyte membrane as the source of daunomycin radicals
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