1,721,327 research outputs found

    The possible role of chemotherapy in antiangiogenic drug resistance

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    The use of antiangiogenic drugs for cancer treatment was welcomed because of the hypothesis that they would be much less likely to lose their therapeutic activity as a result of tumor-acquired resistance over time. Unfortunately, the clinical experience has shown that acquired resistance to antiangiogenic therapeutic strategies is possible since many patients whose tumors initially respond to drugs such as bevacizumab (a monoclonal antibody against VEGF), sorafenib, or sunitinib (tyrosine kinase inhibitors targeting VEGF receptors and PDGF receptors) or metronomic chemotherapy (e.g. low dose cyclophosphamide) become nonresponsive, often within months of therapy initiation. Indeed, the role of associated antineoplastic chemotherapy in antiangiogenic resistance seems to be ignored by the previous studies and the real part played by these drugs has to be written yet. The studies undertaken on antiangiogenic resistance mainly involved mechanisms directly related to the antiangiogenic drugs alone and as such lead one to ask whether the acquired resistance to angiogenesis pathway-targeting might also be mediated by the chemotherapeutic drugs usually associated (at least into the clinic) with these types of drugs. The proposed hypothesis is concerning the possibility that the acquired resistance to antiangiogenic therapy could be actively and heavily modulated by the choice of the associated chemotherapeutic drug. The chemotherapeutic compounds may delay or accelerate the process through the induction, upregulation or downregulation of pro-angiogenic or anti-angiogenic factors or their receptors in the tumor, endothelial and other type of cells of the tumor microenvironment. In conclusion, the consequences of our hypothesis could be promptly translated into the preclinical studies and verified in clinical trials, involving cancer patients resistant to chemotherapy plus antiangiogenic drug schedules

    Early tumour shrinkage (ETS) and its impact on tumour-related symptoms in patients with previously untreated RAS wild-type (WT) metastatic colorectal cancer (mCRC): a retrospective analysis of three panitumumab (pmab) studies

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    Abstract no. V367 Annual Meeting of the German, Austrian and Swiss Societies for Hematology and Medical OncologyGeißler M., Taieb J., Rivera F., Karthaus M., Wilson R., Loupakis F., Price T., Tracy M., Burdon P., Peeters M

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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
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