1,721,033 research outputs found
Toxicity of cisplatin and its metabolites on ovarian cancer cells.
No full textCisplatin (CP) is one of our most useful antineoplastic drugs. When CP is dissolved in human plasma, different metabolites are formed. We examined the interactions of CP and its metabolites, namely aquated CP (AP), monomethionine CP (MP), bismethionine CP (BP) and CP dissolved in plasma ultrafiltrate (UP) on the OV 2008 human ovarian cancer cell line. By clonogenic assays, cell survivals (%) with AP, CP, MP, BP and UP were 3.28 0.73, 9.84 0.99, 15.93 1.11, 76.83 2.13 and 13.11 0.74, respectively. AP was the most cytotoxic species, and BP was the least cytotoxic species. Cellular platinum (ng/10\sp6 cells) accumulation after addition of 0.33 (#1), 1.6 (#2) and 2.5 (#3) mM of each species was:(UNFORMATTED TABLE OR EQUATION FOLLOWS)\vbox{\halign{#\hfil&&\enspace#\hfil\cr\lbrack Species\rbrack &CP &AP &MP &BP &UP\cr\cr \#1 &289$\pm$26 &1080$\pm$90 &138$\pm$5 &24$\pm$1 &187$\pm$26\cr \#2 &607$\pm$31 &4352$\pm$145 &372$\pm$8 &56$\pm$2 &498$\pm$69\cr \#3 &713$\pm$41 &6610$\pm$279 &710$\pm$8 &78$\pm$2 &711$\pm$96\cr}}(TABLE/EQUATION ENDS) There is a strong correlation between cytotoxicity of the platinum species and their cellular uptake (r = 0.997). Infrared spectroscopy (IR) was done on OV 2008 cells after one hour exposure to different concentrations of species. IR data suggest that MP induced more cellular changes than the other species. While bands of all CP metabolites attributed to the phosphate and amide II stretching indicate a frequency shift and intensity variation, those of methyl and methylene stretching vibrations of the cell membrane seem to be hardly affected. In conclusion, CP and its metabolites have different effects on OV 2008 cells
Cisplatin-induced cytotoxicity in MDCK cells.
No full textBackground. The mechanism of cisplatin-induced nephrotoxicity is not well understood. The distal tubules are affected in both human and animal studies, although the majority of cisplatin-induced renal damage is in proximal tubules. Platinum (Pt) forms intra- and interstrand cross-links with DNA in cancer cells. Hypothesis. A mechanism of cisplatin-induced cytotoxicity in MDCK cells relates to its ability to bind to DNA and interfere with its synthesis. Methods. The canine distal renal tubular epithelial cell line, MDCK was used as an in vitro model to investigate the mechanism of cisplatin-induced nephrotoxicity. The intracellular Pt accumulation and Pt binding with DNA were assayed by atomic absorption spectrophotometry. DNA synthesis was measured by BrdU labeling and fluorescence microscopy at the concentrations from 0 to 100 muM. The alkaline comet assay with 10 Gy radiation was used to measure Pt DNA interstrand cross-links after a one hour cisplatin exposure from 0 to 100 muM at both zero and sixteen hour time points. According to the principles of alkaline comet assay, the tail moment is inversely related with the amount of Pt interstrand cross-links. (Abstract shortened by UMI.
Cisplatin-induced cytotoxicity in MDCK cells.
No full textBackground. The mechanism of cisplatin-induced nephrotoxicity is not well understood. The distal tubules are affected in both human and animal studies, although the majority of cisplatin-induced renal damage is in proximal tubules. Platinum (Pt) forms intra- and interstrand cross-links with DNA in cancer cells. Hypothesis. A mechanism of cisplatin-induced cytotoxicity in MDCK cells relates to its ability to bind to DNA and interfere with its synthesis. Methods. The canine distal renal tubular epithelial cell line, MDCK was used as an in vitro model to investigate the mechanism of cisplatin-induced nephrotoxicity. The intracellular Pt accumulation and Pt binding with DNA were assayed by atomic absorption spectrophotometry. DNA synthesis was measured by BrdU labeling and fluorescence microscopy at the concentrations from 0 to 100 muM. The alkaline comet assay with 10 Gy radiation was used to measure Pt DNA interstrand cross-links after a one hour cisplatin exposure from 0 to 100 muM at both zero and sixteen hour time points. According to the principles of alkaline comet assay, the tail moment is inversely related with the amount of Pt interstrand cross-links. (Abstract shortened by UMI.
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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