1,720,969 research outputs found
The Alternative TrkAIII splice variant by neuroblastomas and glioblastomas targets the centrosome and promotes genetic instability
No full text
Increased matrix metalloproteinase-9 secretion in short-term tissue cultures of prostatic tumor cells
No full textWe have examined the expression of 2 tumor-associated metalloproteinases, MMP-2 and MMP-9, in 48 primary cultures of prostatic carcinoma (PRCA) and 33 cultures of benign prostatic hyperplasia (BPH). PRCA cultures secrete significantly more MMP-9 than their benign counterparts. Secreted MMP-2 did not differ significantly in cultures but was lower in PRCA cultures. Two cultures of benign origin exhibited high MMP-9 secretion and growth patterns consistent with a malignancy. Both cases were followed and successively re-evaluated histologically and rediagnosed as organ-confined PRCA. MMP expression in culture may be of predictive value in the identification of incidental PRCA. MMP-9 secretion and its ratio with MMP-2 were highest in epithelial cultures from invasive, metastatic tumors when compared both to disease confined to prostate gland and to locally extensive disease. MMP-9 secretion was greatest also in cultures derived from tissues of high Gleason histological grade. Active MMP-9 species were detected in 15 cultures (31%) of PRCA. Active MMP-2. species were observed in cultures of both BPH and PRCA origin in almost the same amounts. Although average levels were not significantly different, as a ratio to preform species, a significant elevation was observed in cultures of PRCA origin. We propose, therefore, that an elevated expression of MMP-9 and a high ratio of MMP-9 to MMP-2 in short-term prostate epithelial cultures is of potential diagnostic and prognostic significance. (C) 1996 Wiley-Liss, Inc
bc1-2 over-expression enhances NF-kappa B activity and induces mmp-9 transcription in human MCF7(ADR) breast-cancer cells
No full textbcl-2 expression is often associated with poor prognosis in several types of tumors; however, the role of this molecule in breast cancer is still controversial. We found earlier that over-expression of bcl-2 in a human breast-cancer cell line (MCF7(ADR)) enhances its tumorigenicity and metastatic potential by inducing metastasis-associated properties such as increased secretion of the matrix metalloproteinase-9 (mmp-9), In the present study, we investigated the effect of bcl-2 over-expression on the activity of the transcription factor NF-kappa B, an important regulator of genes involved in tumor progression and invasion. Transient transfection experiments indicate that over-expression of bcl-2 in the MCF7(ADR) call line, enhances NF-kappa B-dependent transcriptional activity. Mobility-shift analysis revealed an increase of NF-kappa B DNA-binding in bcl-2-over expressing clones that correlated with lower levels of the NF-kappa B cytoplasmic inhibitor I kappa B alpha. Moreover, point mutations of 2 highly conserved residues within the BH1 and BH2 domains that abrogate the interaction of bcl-2 with bar, or deletion of the N-terminal BH4 domain, completely eliminate the ability of this molecule to up-regulate NF-kappa B-dependent transactivation. Since mmp-9 is a NF-kappa B-regulated gene, we also investigated whether bcl-2 overexpression up-regulated mmp-9 transcription. We found that induction of mmp-9 mRNA correlates with the activation of an mmp-9-promoter-reporter-gene construct in transient transfection assay. and a mutation of the (-600)mmp-9-NF-kappa B binding element abolishes this effect. The overall data indicate that bcl-2-mediated regulation of NF-kappa B-transcription-factor activity may represent an important mechanism for the promotion of malignant behavior in MCF-7(ADR) cells. Int J. Cancer 86:188-196, 2000. Q 2000 Willey-Liss, Inc
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
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