1,720,964 research outputs found
Immunohistochemical Analysis and Pathological Assessment of B-Cbl Proto-Oncogene in Gastric Carcinoma Cells
No full textPropriétés oncogéniques des facteurs de transcription STAT5
No full textLes études chez la souris ont montré que les facteurs de transcription STAT5 sont nécessaires à la prolifération et /ou à la survie des cellules hématopoïétiques. Ces protéines jouent un rôle important dans les propriétés transformantes de certaines oncoprotéines telles que Bcr-Abl, Tel-Abl et Tel-Jak2 et sont souvent constitutivement activées dans les cellules de tumeurs solides ou de patients leucémiques. Leur implication directe dans la genèse de leucémie a été démontrée par l utilisation de formes mutées constitutivement actives de STAT5 (cS5F et STAT51*6). Afin de comprendre les mécanismes moléculaires mis en jeu dans l activité oncogénique de STAT5, nous avons étudié les propriétés transformantes de cS5F dans les cellules primaires de moelle osseuse de souris ainsi que dans la lignée cellulaire Ba/F3. L expression de cS5F dans les cellules de moelle osseuse de souris conduit, en effet, à l induction d une leucémie multi-linéage après transplantation de ces cellules dans des souris receveuses et rend les cellules Ba/F3 indépendantes de l IL-3 pour leur prolifération. Nos résultats montrent aussi bien dans les cellules primaires leucémiques que dans les cellules Ba/F3 que cS5F induit l activation d Akt un effecteur crucial de la voie PI 3-kinase. Cette activation passe par une interaction entre la sous-unité régulatrice de la PI 3-kinase, p85 et la molécule adaptatrice Gab2. L utilisation de formes mutées de Gab2 ou d Akt et d un inhibiteur pharmacologique de la PI 3-kinase montre que l activation de la voie Gab2/PI 3-kinase/Akt joue probablement un rôle essentiel dans les propriétés leucémogènes de cS5F. Les résultats des études immuno-cytochimiques et de Western blot sur des extraits nucléaires et cytoplasmiques avec un anticorps anti-P-Y-Stat5 montrent que cS5F est majoritairement localisé dans le cytoplasme des cellules leucémiques, soutenant donc nos observations d un rôle actif de cette protéine oncogénique dans ce compartiment cellulaire. Des résultats similaires ont été obtenus sur des cellules et de biopsies médullaires de patients leucémiques (LMC, LAM et mastocytoses), montrant ainsi que cette localisation inhabituelle des formes actives de STAT5 n est pas liée à une propriété spécifique de cS5F. La présence de formes phosphorylées de STAT5 dans les mastocytoses nous a conduit à étudier le rôle de STAT5 dans la signalisation de c-Kit, le récepteur au Stem Cell Factor (SCF). Nos résultats montrent que l activation de STAT5, aussi bien dans les cellules de moelle osseuse transformées par cS5F que dans des progéniteurs hématopoïétique humains, joue un rôle important le développement des mastocytes in vitro en présence de SCF et que son activation constitutive contribue à un développement anormal des mastocytes in vivo. L ensemble de nos données suggère que l activation constitutive de STAT5 pourrait promouvoir une localisation et une activité cytoplasmique susceptible d être relié à l activation d autres voies de signalisation comme la voie PI3-K et que l inhibition simultanée de l activité de STAT5 (cytoplasmique et nucléaire) et de la PI 3-kinase pourrait ouvrir des perspectives thérapeutiques intéressantes dans le traitement d hémopathies associées à l activation de ces deux voies de signalisation.AMIENS-BU Santé (800212102) / SudocSudocFranceF
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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