1,720,991 research outputs found
Mammalian tumor xenografts induce neovascularization in zebrafish embryos.
No full textThe zebrafish (Danio rerio)/tumor xenograft model represents
a powerful new model system in cancer. Here, we describe a
novel exploitation of the zebrafish model to investigate tumor
angiogenesis, a pivotal step in cancer progression and target
for antitumor therapies. Human and murine tumor cell lines
that express the angiogenic fibroblast growth factor (FGF) 2
and/or vascular endothelial growth factor (VEGF) induce the
rapid formation of a new microvasculature when grafted close
to the developing subintestinal vessels of zebrafish embryos at
48 h postfertilization. Instead, no angiogenic response was
exerted by related cell clones defective in the production of
these angiogenic growth factors. The newly formed blood
vessels sprout from the subintestinal plexus of the zebrafish
embryo, penetrate the tumor graft, and express the transcripts
for the zebrafish orthologues of the early endothelial markers
Fli-1, VEGF receptor-2 (VEGFR2/KDR), and VE-cadherin.
Accordingly, green fluorescent protein–positive neovessels
infiltrate the graft when tumor cells are injected in transgenic
VEGFR2:G-RCFP zebrafish embryos that express green fluorescent
protein under the control of the VEGFR2/KDR
promoter. Systemic exposure of zebrafish embryos immediately
after tumor cell injection to prototypic antiangiogenic
inhibitors, including the FGF receptor tyrosine kinase inhibitor
SU5402 and the VEGFR2/KDR tyrosine kinase inhibitor
SU5416, suppresses tumor-induced angiogenesis without
affecting normal blood vessel development. Accordingly,
VE-cadherin gene inactivation by antisense morpholino
oligonucleotide injection inhibits tumor neovascularization
without affecting the development of intersegmental and
subintestinal vessels. These data show that the zebrafish/
tumor xenograft model represents a novel tool for investigating
the neovascularization process exploitable for drug
discovery and gene targeting in tumor angiogenesis
Antiangiogenic and vascular-targeting activity of the microtubule-destabilizing trans-resveratrol derivative 3,5,4'-trimethoxystilbene.
No full textFunctional analysis of the cfdp1 gene in zebrafish provides evidence for its crucial role in craniofacial development and osteogenesis
No full textThe CFDP1 proteins have been linked to craniofacial development and osteogenesis in vertebrates, though
specific human syndromes have not yet been identified. Alterations of craniofacial development represent the
main cause of infant disability and mortality in humans. For this reason, it is crucial to understand the cellular
functions and mechanism of action of the CFDP1 protein in model vertebrate organisms. Using a combination of
genomic, molecular and cell biology approaches, we have performed a functional analysis of the cfdp1 gene and
its encoded protein, zCFDP1, in the zebrafish model system. We found that zCFDP1 is present in the zygote, is
rapidly produced after MTZ transition and is highly abundant in the head structures. Depletion of zCFDP1,
induced by an ATG-blocking morpholino, produces considerable defects in craniofacial structures and bone
mineralization. Together, our results show that zCFDP1 is an essential protein required for proper development
and provide the first experimental evidence showing that in vertebrates it actively participates to the morphogenesis
of craniofacial territories
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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