1,721,187 research outputs found
Antisense agrin cDNA transfection blocks neuroblastoma cell-induced acetylcholine receptor aggregation when co-cultured with myotubes
No full textA neuroblastoma x glioma hybrid cell line, NG108-15, was able to induce the aggregation of AChRs when co-cultured with myotubes. NG108-15 cells in culture expressed agrin, producing a protein of ~220 kDa and a transcript of ~8.0 kb. The mRNA encoding the agrin isoform having no amino acid insertion at either the Y or the Z site, namely agrin0,0, was the only transcript detected in NG108-15 cells when they were cultured alone or co-cultured with myotubes. NG108-15 cells could be induced to differentiate by chemical treatment, and the chemical-induced differentiation of NG108-15 cells increased the level of agrin mRNA expression approximately fourfold while the expression of a housekeeping gene remained relatively unchanged. The increase in agrin expression of differentiated NG108-15 cells paralleled the increase in AChR-aggregating activity of differentiated NG108-15 cells, indicating that the agrin derived from NG108-18 cells could be the receptor-aggregating factor. In addition, we created a stable clonal NG108-15 cell line that was transfected with antisense agrin cDNA and its expression of agrin was abolished, while its AChR-aggregating activity was completely lost when co- cultured with myotubes. This is the first direct demonstration that NG108-15 cell-induced AChR aggregation on cultured myotubes is mediated by neuron- derived agrin.</p
A Review of Edible Jujube, the Ziziphus jujuba Fruit: A Heath Food Supplement for Anemia Prevalence
No full textThe fruits of Ziziphus jujuba, commonly known as jujube, red date or Chinese date, are taken as fresh or dried food, and as traditional medicine worldwide due to high nutritional and health values. Traditionally in China, jujube is considered as a medicinal fruit that is being used in treating blood deficiency. In this review, the beneficial effects of jujubes on the hematopoietic functions are summarized and discussed. As illustrated in cell and animal models, the application of jujube extract possessed beneficial effects, including regulation of erythropoiesis via activation of hypoxia inducible factor-induced erythropoietin, potential capacity in recycling heme iron during erythrophagocytosis and bi-directional regulation of immune response. Thus, the blood-nourishing function of jujube is being proposed here. Flavonoid, polysaccharide and triterpenoid within jujube could serve as the potential active ingredients accounting for the aforementioned health benefits. Taken together, these findings provide several lines of evidence for further development of jujube as supplementary products for prevention and/or treatment of anemia.</p
Truncated form of pro-acetycholine receptor-inducing activity (ARIA) induces AChR α-subunit but not AChE transcripts in cultured chick myotubes
No full textAcetylcholine receptor-inducing activity (ARIA) is a glycoprotein initially purified from chick brain based on its ability to increase the synthesis of acetylcholine receptor (AChR). We used reverse transcription-polymerase chain reaction (RT PCR) to obtain a partial pro-ARIA cDNA clone from methonine-1 to serine-358 including the full functional sequence of ARIA. Northern blot analysis of mRNAs from the embryonic chick brain and muscle showed a transcript with a size of ∼7.5 kb. The cloned cDNA was subcloned into an eukaryotic expression vector and stably transfected into human embryonic kidney 293 cells. The conditioned medium of the transfected cells was found to increase the level of transcript encoding for the α-subunit of AChR by ∼4.4-fold, but not for acetylcholinesterase (ACNE), in the cultured chick myotubes.</p
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
Evidence for the involvement of essential sulphydryl group in rat hepatic lactogenic receptor but not in somatogenic receptor
No full textIncorporation of P-chloromercuribenzene sulphonate (PCMBS) (1mM) in the assay medium for rat hepatic lactogenic receptor produced complete inhibition of binding of [125I]oPRL to the membrane. However, the presence of the thiol-reactive agent produced no effect on the binding of [125I]bGH to rat hepatic somatogenic receptor. Pretreatment of rat hepatic membrane with PCMBS inhibited the binding of [125I]oPRL but not that of [125I]bGH. The lactogenic receptor binding inhibition by PCMBS pretreatment was both concentration- and time-dependent, with complete inhibition at 0.5 mM for 60 min at 0°C. Scatchard analysis of [125I]oPRL binding to membrane at 50% inhibition by PCMBS (0.11 mM) revealed that the binding capacity was decreased rather than the binding affinity. Furthermore, the inhibition of lactogenic receptor binding by PCMBS could be reversed by dithioerythritol (DTE) treatment. Following 80% inhibition by 0.2 mM PCMBS, full recovery of receptor binding was achieved at 6 mM DTE for 60 min at 0°C. The 'recovered' membrane showed no difference from the control membrane in terms of binding capacity and affinity.</p
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
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