1,721,102 research outputs found
Cancer stem cells as functional biomarkers in metastasis.
No full textTumors are heterogeneous diseases as emerged since the earliest pathological examinations. In the clinical setting this heterogeneity is evident, for instance, when we observe patients whose lesions have a different, if not opposite, patterns of response following the delivery of systemic anticancer treatments. We are now beginning to understand branched evolution and tumor heterogeneity at the molecular level, and the lesson learned is that different metastatic lesions, or even different regions within the primary tumor, carry a distinct pattern of genetic abnormalities [1]. While some mutations are conserved across different metastatic sites coexisting in the same patients, others are “private” and confined to a given region or metastatic site [1]. For decades this heterogeneity was explained by the “stochastic” or “clonal evolution model”, that relied on Darwinian principles of evolution [2]. Another model has been proposed following the description of a stringent hierarchical organization in human acute myeloid leukemias [3]. By taking advantage of flow cytometry, tumorigenic and non-tumorigenic cells within the same tumor have been isolated, allowing to envision a pyramidal organization [3]. This model, commonly referred to as the “hierarchical model”, states that the entire tumor population descends from a common progenitor, represented by a CSC at the apex of the pyramid [4]. In this manuscript, we briefly describe the CSC model, key functional properties of CSCs, and how the growing body of knowledge on CSCs has been translated into clinical studies with the purpose of investigating CSC-associated biomarkers or therapeutics for CSC targeting
Cancer Stem Cells
No full textDifferent tissue-specific cancer stem cells ( CSCs) have been isolated from both big killers and rare cancers. Four properties are adopted to define CSC: 1) expression of a distinctive repertoire of cell surface markers for isolation and purification;2) formation of tumorspheres in suspension culture;3) tumorigenic capacity in immunocompromised mice;4) generation of a heterogeneous cancer tissue closely resembling the original tumor. CSCs constitute a minority of the cells within a tumor but this population is critical for tumor propagation. It is reasonable that CSC can initiate a metastatic lesionand than thrive in a tumor-hostile microenvironment. CSCs actively contribute to tumor vascularization by serving as vascular progenitors. CSCs are in the order of 0,1% in primary tumors. Given the long experience gained with the development of MRI and PET, these technologies have more possibilities to be adopted in the clinic with the specific aim of monitoring the CSCs pool
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
Role of autophagy in the maintenance and function of cancer stem cells
Full text linkRecent advances in experimental technologies and cancer models have made possible to demonstrate that the tumor is a dynamic system comprising heterogeneous populations of cancer cells organized in a hierarchical fashion with cancer stem cells (CSCs) at the apex. CSCs are immature cells characterized by self-renewal property and long-term repopulation potential. CSCs have been causally linked to cancer initiation, propagation, spreading, recurrence and relapse as well as to resistance to anticancer therapy. A growing body of evidence suggests that the function and physiology of CSCs may be influenced by genetic/epigenetic factors and tumor environment. In this context, macroautophagy is a lysosomal degradative process (herein referred to as autophagy) critical for the adaptive response to stress and the preservation of cellular and tissue homeostasis in all eukaryotes that may have a crucial role of in the origin, maintenance and invasiveness of CSCs. The activation of the autophagic machinery is also considered as an adaptive response of CSCs to perturbation of tumor microenvironment, caused for instance by anticancer therapy. Nevertheless, compelling preclinical and clinical evidence on the cytoprotective role of autophagy for CSCs is still missing. Here, we summarize the results on the contribution of autophagy in CSCs and how it impacts tumorigenesis and tumor progression. We also discuss the therapeutical potential of the modulation of autophagy as a means to eradicate CSCs
- …
