1,720,953 research outputs found
The use of combination tyrosine kinase inhibitors for the treatment of glioblastoma multiforme
Get PDFGlioblastoma is the most common primary brain tumor which has a median survival of only 14.6 months. The central nervous system localization, heterogeneity of the cells and resistance to treatment constitute a significant challenge to establishing an efficient and durable therapy. Glioblastoma lesions contain a dense network of defective blood vessels which are permeable to high molecular weight constructs such as nanocarriers. Furthermore, glioblastoma lesions are known to depend upon several tyrosine kinases in order to facilitate their development, progression, invasion and treatment resistance.
As a consequence, we assessed the cytotoxicity of multiple tyrosine kinase inhibitors (TKIs), singularly or in combination, against a panel of glioblastoma cell lines in vitro. The most promising combination of crizotinib, an inhibitor of Met and ROS1, and dasatinib, an inhibitor of SRC and focal adhesion kinase (FAK), were pursued as the lead compounds. In addition, these TKIs were encapsulated into polystyrene co-maleic acid micelles to improve their pharmacokinetic profiles in vivo by selective accumulation in tissues with fenestrated vasculature. The micelles were characterized based on their loading, charge, size, solubility and release rate. Both formulations were assessed for their ability to alter protein expression profiles, induce cell death and reduce proliferation. The ability of the treatments to prevent migration, invasion and angiogenesis in a panel of glioblastoma cell lines was also assessed.
The micelles had favorable physicochemical characteristics, with a size sufficient to promote a prolonged plasma half-life, a near neutral charge to prevent opsonization and a steady release rate. The expression and phosphorylation of the target kinases Met, ROS1, SRC, and FAK were consistently reduced by the combination treatment. The combination treatment also reduced the expression of EGFR despite neither TKI targeting this receptor. The inhibition of these targets and subsequent suppression of downstream AKT activity induced apoptotic cell death in glioblastoma cells. The cell death following removal of the drug after a 72 h treatment period, defined as washout, was assessed to determine the ability of the cells to escape from treatment-induced cell death. Following washout, the apoptosis was maintained for 72 h following the removal of the drugs in the free but not the micellar formulations. The induction of cell death correlated with the induction of polyploidy in the free but not micellar formulations. This polyploidy was not causative of cell death but was associated with genetic instability. Both free and micellar formulations showed effective prevention of invasion, migration and angiogenesis in vitro.
This study demonstrated the efficacy of the combination of crizotinib and dasatinib in a panel of glioblastoma cell lines. This combination strongly induced apoptotic cell death. Furthermore, the combination also effectively combated several treatment resistance pathways such as invasion and vascular mimicry, potentially augmenting the efficacy of the current therapies. The micellar formulations show comparable efficacy to the free formulations but also provide the potential for the improvement of in vivo pharmacokinetic parameters. In conclusion, the combination of crizotinib and dasatinib shows significant promise in vitro and warrants further investigation in vivo for the treatment of glioblastoma
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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