1,720,971 research outputs found
Destination 'Lysosome': a target organelle for tumour cell killing?
No full textLysosomes and lysosome-related organelles constitute a system of acid compartments that interconnect the inside of the cell with the extracellular environment via endocytosis, phagocytosis and exocytosis. In recent decades it has been recognized that lysosomes are not just wastebaskets for disposal of unused cellular constituents, but that they are involved in several cellular processes such as post-translational maturation of proteins, degradation of receptors and extracellular release of active enzymes. By complementing the autophagic process, lysosomes actively contribute to the maintenance of cellular homeostasis. Proteolysis by lysosomal cathepsins has been shown to mediate the death signal of cytotoxic drugs and cytokines, as well as the activation of pro-survival factors. Secreted lysosomal cathepsins have been shown to degrade protein components of the extracellular matrix, thus contributing actively to its re-modelling in physiological and pathological processes. The malfunction of lysosomes can, therefore, impact on cell behaviour and fate. Here we review the role of lysosomal hydrolases in several aspects of the malignant phenotype including loss of cell growth control, altered regulation of cell death, acquisition of chemoresistance and of metastatic potential. Based on these observations, the lysosome is proposed as a potential target organelle for the chemotherapy of tumours. We will also present some recent data concerning the technologies for delivering chemotherapeutic drugs to the endosomal-lysosomal compartment and the strategies to improve their efficacy
High levels of proteolytic enzymes in the ascitic fluid and plasma of rats bearing the yoshida AH-130 hepatoma
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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
Differentiation-induced changes in the content, secretion, and subcellular distribution of lysosomal cathepsins in the human colon cancer HT-29 cell line
No full textEFFECTS OF CALCITRIOL ON THE BIOGENESIS OF A LYSOSOMAL PROTEASE IN MONOCYTES FROM PATIENTS WITH RENAL-FAILURE
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