1,721,021 research outputs found
Hepatocyte growth factor enhances CXCR4 expression favoring breast cancer cell invasiveness
No full textMicroenvironmental factors affect different aspects of tumor cell biology, including cell survival, invasion, and metastasis. Here, we report that hepatocyte growth factor and hypoxia may contribute to breast carcinoma cell invasiveness by inducing the chemokine receptor CXCR4. Hepatocyte growth factor enhanced CXCR4 mRNA and protein expression exclusively in MCF-7 (low invasive) carcinoma cells, while in response to hypoxia, CXCR4 induction was observed in both MCF-7 and MDA-MB 231 (highly invasive) carcinoma cells. The receptor induction had a functional role in cancer cells, as demonstrated by the fact that hepatocyte growth factor pretreatment promoted MCF-7 cell migration toward the CXCR4-specific ligand CXCL12. Extracellular signal-regulated protein kinase 1/2 (ERK1/2) and phosphoinositide-3-kinase (PI3K) transduction pathways seemed to be differently implicated in the early induction of CXCR4 by hepatocyte growth factor or hypoxia in the two breast carcinoma cells examined
Hepatocyte growth factor differently influences Met-E-cadherin phosphorylation and downstream signaling pathway in two models of breast cells
No full textE-cadherins are implicated in cell adhesion, and also in cell signaling by associating with tyrosine kinase-receptors such as Met, the hepatocyte growth factor (HGF) receptor. Using two different cellular models, i.e. MCF-7 (breast carcinoma) and MCF-10 (immortalized mammary) cells, we studied the possible mechanism(s) by which E-cadherins modulate the signaling pathways downstream of Met, leading to beta-catenin-TCF transcriptional activity. In MCF-7, but not in MCF-10 cells, E-cadherins were remarkably associated with Met. Moreover, in MCF-7 cells both co-immunoprecipitation with anti-Met antibody and co-localization were increased by 30-min HGF treatment, which caused E-cadherin tyrosine phosphorylation. Also beta-catenin in the co-immunoprecipitate was phosphorylated by HGF, probably favoring TCF activation. Consistently, after HGF treatment, beta-catenin redistributed earlier in MCF-7 than in MCF-10 cells, with nuclear accumulation and activation of TOPFLASH gene reporter. Our results indicate a functional role of Met-E-cadherin interaction in MCF-7 cells through the amplification of the signaling downstream of HGF-Met triggering that involved c-Src and phosphoinositide-3-kinase activities
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
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
Fertility preservation in female cancer patients: an emerging challenge for physicians
No full textFertility preservation has become an issue of great importance in female cancer patients due
to increasing survival rates and delayed childbearing. It is an emerging challenge for
physicians, cause of several related issues (multidisciplinary approach, doctor-patient
communication, ethical, religious and legal problems) and many unresolved questions.
This review aims to update the latest literature data, summarizing the effects of cancer
treatments on female fertility and the various options currently available to offer cancer
patients the opportunity of future pregnancies.
Many strategies exist for fertility preservation in young women and they should be assessed
according to the patient’s age, type of cancer, partner status and time available. Some
techniques are well established, others are still experimental. The established methods include
embryo cryopreservation, transposition of ovaries prior to radiation therapy, radiation
shielding of gonads and conservative surgical approaches. The experimental methods include
oocyte cryopreservation, in vitro maturation of oocytes, ovarian tissue cryopreservation and
transplantation, and ovarian suppression. Improvement of these techniques as well as better
characterization of their success rates and risks, await further investigation. Oocytes donation
and gestational surrogacy represent the last options.
Thus, the care of these patients is challenging, complex and requires a multidisciplinary
approach. A close collaboration between Oncologists, Specialists in Reproductive Medicine,
Gynecologic Oncologists and Endocrinologists is crucial for always offering the best possible
option
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