1,720,988 research outputs found
ACID SPHINGOMYELINASE AND MITOCHONDRIA: A NEW LINKIN CHEMOTHERAPEUTIC DRUGS INDUCED APOPTOSIS
No full textMelanoma is the most aggressive form of skin cancer and is notoriously resistant to all current modalities of cancer therapy. Malignant melanomas are composed of subpopulations of cells characterized by highly heterogeneity.
This clonal heterogeneity of tumor cells accounts for the existence or appearance of tumor cell populations showing invasive and metastatic phenotype heterogeneity, different drug resistance and immunogenicity.
Over the past twenty years, sphingolipids have emerged as bioeffector molecules, controlling various aspects of cell growth and proliferation in cancer and in particular A-SMase is known to be involved in the apoptotic process and, moreover, to be activated by many chemotherapeutic drugs.
In this work we focused our attention on the investigation of the role of ASMase in regulation of chemoresistance.
To this end we used the B16-W6 clone that was isolated from a murine melanoma cells lines, B16-F1, and that showed high A-SMase expression and the B16-W6_pSiL10 clone generated from the A-SMase highly expressing clone B16-W6.
In particular, here it has been demonstrated a pivotal role of A-SMase in the regulation of the balance between apoptosis and autophagy.
In our previous work we have found that the downregulation of A-SMase is correlated with high Microphtalmia-associated transcription factor (Mitf) expression.
Since it is establish that Mitf regulates Hypoxia-inducible factor-1α (HIF-1α), an important transcription factor involved in chemoresistance of solid tumor, we decided to examine the possible connection between A-SMase and HIF-1α through the regulation of Mitf and what is its biological significance.
We demonstrated, for the first time, that the decrease in expression of A-SMase correlates with an increased amount of HIF-1α in normoxia and this increase is responsible for the induction of autophagy.
Investigating the mechanism by which A-SMase resulates the autophagic process, we found that A-SMase was able to regulate BNIP3 through the modulation of HIF-1α expression.
The A-SMase/Mitf/HIF-1α axis is also responsible for the modification of mitochondrial morphology and functionality.
Of particular interest, we demonstrated that the induction of autophagy is in part responsible for the resistance of chemotherapy due to the A-SMase downregulation. Indeed, we found that the inhibition of autophagy in B16-W6_pSiL10 clone restored the sensitivity to the chemotherapy.
From all these results A-SMase results to be fundamental for the response of melanoma cells to the chemotherapeutic treatment and a protein to be further investigated in perspective of new and more effective anticancer strategies
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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