1,720,996 research outputs found
BIOLOGICAL AND MOLECULAR CHARACTERIZATION OF CMA-03/06, A NEWLY ESTABLISHED INTERLEUKIN-6 INDEPENDENT VARIANT OF THE CMA-03 HUMAN MYELOMA CELL LINE.
No full textThe growth and survival of multiple myeloma (MM) cells in the bone marrow microenvironment is regulated by functional complex interactions between the tumor cells and the surrounding bone marrow stromal cells mediated by adhesion molecules and the production of several cytokines of which interleukin-6 (IL-6) has been identified as the most important. Major advances in the investigation of MM biology were made possible by the availability of human myeloma cell lines (HMCLs). The IL-6-dependent CMA-03 cell line was established in our laboratory from a peritoneal effusion of a refractory relapsed MM patient. By gradually decreasing the IL-6 added to the culture, an IL-6-independent variant, CMA-03/06, could be obtained.
The aim of this study was to perform a biological and molecular characterization of this novel cell line and to provide insights into the signaling pathways and target genes involved in the growth and survival of CMA-03/06.
The growth, immunophenotypic, cytogenetic and fluorescence in situ hybridization (FISH) characterization of CMA-03/06 cell line was performed by means of standard procedures. IL-6 production into the culture media was determined using a high sensitivity IL-6 specific ELISA. Genome-wide profiling data were generated by means of Affymetrix GeneChip Human Mapping 250K NspI arrays; copy number (CN) alterations were calculated using the DNAcopy Bioconductor package, based on circular binary segmentation method. Global gene expression profiling (GEP) was performed by means of the GeneChip Human Gene 1.0 ST Arrays (Affymetrix); the supervised analyses were done using the rank Prod method and a 2 fold change cut off.
The immunophenotypic analysis of the two cell lines showed a significant difference in the expression of three antigens: CD45 was considerably reduced in CMA-03/06 cells, whereas they were found positive for both chains of IL-6 receptor, CD126 and CD130, almost undetectable in CMA-03. Conventional cytogenetic and FISH analyses did not reveal differences between the 2 HMCLs. Unlike CMA-03, the addition of IL-6 to the culture medium of CMA-03/06 cells or co-culture with multipotent mesenchymal stromal cells did not induce an increase in CMA-03/06 proliferation. IL-6 was not detected in the supernatants from either CMA-03 or CMA-03/06 cell lines within 48 h, suggesting that the IL-6 independence of CMA03/06 cells is not a result of the development of an autocrine IL-6 loop. Nevertheless, IL-6 induced the activation of STAT3 and STAT1 in both cell lines, even if a slight constitutive STAT3 phosphorylation was found in CMA-03/06. The genome-wide analysis allowed the identification of about 100 altered chromosomal regions common to both HMCLs, mostly DNA gains. Comparison of CMA-03/06 and CMA-03 cells evidenced a different CN in only 15 small chromosomal regions, 8 of which did not contain any transcript, whereas few genes were located on the other ones. GEP analysis of CMA-03/06 compared with CMA-03 identified 140 upregulated and 168 downregulated genes, many of which particularly relevant for MM biology, mainly involved in cellular signaling, cell cycle, cell adhesion, cell development, regulation of transcription, immunologic, inflammatory or defense activity, cytokine receptor activity, apoptosis. None of the genes differentially expressed in CMA-03/06 compared with CMA-03 except 2 were positioned on the chromosomal regions showing a different CN. Finally, CMA-03/06 cell line showed a lower susceptibility to camptothecin-induced apoptosis compared to CMA-03 cells.
The novel CMA03/06 cell line may thus represent a suitable model for studies investigating molecular mechanisms involved in clonal evolution towards IL-6 and/or stroma-independent growth and survival of myeloma cells
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
Biological and molecular characterization by integrative genomics approach of CMA-03/06, a newly established interleukin-6 independent variant of the CMA-03 human myeloma cell line
No full textAppropriate 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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