1,720,987 research outputs found
Drosophila melanogaster minifly mutants: a model system for the study of the molecular basis of the X-linked Dyskeratosis Congenita.
No full textGreen tea and bone marrow transplantation: from antioxidant activity to enzymatic and multidrug-resistance modulation
No full textEpigallocatechin-3-gallate (EGCG), the main flavonoid of Green Tea (GT), could play an active role in the prevention of oxidative stress related diseases, such as hematological malignancies. Some effects of EGCG are not imputable to the antioxidant activity, but involve modulation of antioxidant enzymes and uric acid (UA) levels. The latter is the major factor responsible of the plasma Non-Enzymatic Antioxidant Capacity (NEAC). However, hyperuricaemia is a frequent clinical feature caused by tumor lysis syndrome or cyclosporine side effects, before and after bone marrow transplantation (BMT). Besides, food-drug interactions could be associated with GT consumption and could have clinical implications.
The molecular mechanisms involved in the redox and drug metabolizing/transporting pathways was discussed with particular reference to the potential role of GT and EGCG in BMT. Moreover, reviewing data on NEAC, isoprostanes, uric acid and various enzymes, from human studies on GT, its extract or EGCG, an increase in NEAC, no effect on isoprostanes and contrasting results on UA and enzymes were observed.
Currently, few and contrasting available evidences suggest caution for GT consumption in BMT patients and more studies are needed in order to better understand the potential impact of EGCG on oxidative stress and metabolizing/transporting systems
Drosophila melanogaster minifly mutants: a model system for the study of the molecular basis of the X-linked Dyskeratosis Congenita.
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
Identification and characterization of MicroRNAs expressed in the mouse eye
Full text linkPURPOSE. MicroRNAs ( miRNAs) are a class of small, endogenous RNAs that negatively regulate gene expression post-transcriptionally by binding to target sites in the 3' untranslated region (UTR) of messenger RNAs. Although they have been found to regulate developmental and physiological processes in several organs and tissues, their role in the eye transcriptome is completely unknown. This study was conducted to gain understanding of their eye-related function in mammals, by looking for miRNAs significantly expressed in the mouse eye by means of high-resolution expression analysis. METHODS. The spatiotemporal localization of miRNAs was analyzed in the murine embryonic and postnatal eye by RNA in situ hybridization ( ISH) using LNA-modified oligonucleotide probes. RESULTS. Seven miRNAs were expressed in the eye with diverse and partially overlapping patterns, which may reflect their role in controlling cell differentiation of the retina as well as of other ocular structures. Most eye-expressed miRNAs overlap with or are in the near vicinity of transcripts derived predominantly from eye cDNA libraries. We found that these transcripts share very similar cellular distribution with their corresponding miRNAs, suggesting that miRNAs may share common expression regulatory elements with their host genes. CONCLUSIONS. The data provide a detailed characterization of expression of eye-enriched miRNAs. Knowledge of the spatiotemporal distribution of miRNAs is an essential step toward the identification of their targets and eventually the elucidation of their biological role in eye development and function
Serum depletion, multidrug resistance and fluorescent probes: methodological implications in free radicals evaluation
No full textIntracellular probes used for oxidative burst evaluation could be a substrate of the multidrug resistance proteins (MDR), which may cause misinterpretation of experimental data. We aimed to study the effect of the culture condition and of the MDR-interfering antioxidant quercetin on free radical measurement in serum depleted HCT-8 cells and chick embryo hepatocytes. Serum depletion and/or quercetin affected the traffic of 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF) and calcein. The comparative results obtained with 2',7'-dichlorofluorescein (DCF) and with the plasma-membrane probe C11-BODIPY 581/591 [4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-undecanoic acid], suggest caution in the use of intracellular probes to evaluate oxidative stress in vitro
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