1,720,976 research outputs found
Valutazione istochimica qualitativa e quantitativa di attività deidrogenasiche in cellule di glioblastoma umano trattate con beta-interferone
No full textHistochemistry of some dehydrogenases in glioblastoma cell line following beta interferon treatment
No full textSomatic mutations at the T-cell antigen receptor in antineoplastic drug-exposed populations: comparison with sister chromatid exchange frequency
No full textOBJECTIVE:
The objective of this study was to assess the genetic effect of occupational exposure to antineoplastic agents.
METHOD:
The influence of occupational handling of cytotoxic drugs was investigated by monitoring the frequency of sister chromatid exchanges (SCE), the percentage of cells with high frequencies of SCE (high-frequency cells, HFC), and the frequency of somatic mutation at the T-cell receptor (TCR) locus in mononuclear cells of exposed hospital nurses. These parameters were also measured in healthy donors and in cancer patients at the time of the diagnosis and following the administration of high doses of cytotoxic drugs requiring stem cell support.
RESULTS:
Our results show that (a) SCE and HFC values in occupationally exposed nurses do not differ from controls, (b) patients with newly diagnosed cancer or following chemotherapy show a number of SCE comparable to those of healthy donors, but a significantly different percentage of HFC, (c) cigarette smokers of all categories studied show higher frequencies of SCE and HFC as compared to nonsmokers, but the differences are not statistically significant, (d) the mutation frequency at the TCR locus in oncology nurses is higher, but not significantly different from the frequency in the control group, and (e) the increase of mutation frequency is statistically significant and seems to be dose dependent in patients treated with high-dose chemotherapy.
CONCLUSIONS:
Our data suggest that SCE frequency and HFC percentage are not reliable indicators of exposure to possible mutagenic/carcinogenic effects of antineoplastic drugs; on the contrary, our observations indicate that anticancer therapy induces somatic mutations at the TCR locus and suggest an association between exposure to cytotoxic agents and the increase in somatic mutations
Morphological and biochemical features of a medroxyprogesterone acetate (MPA)-resistant MCF-7 breast cancer cell line
No full textAn MCF-7 human breast cancer line variant (MCF-7/MPA), resistant to medroxyprogesterone-acetate (MPA), was obtained by continuous exposure in vitro to the drug. MCF-7/MPA cells were grown in the presence of 12.5 x 10(-6) M MPA and were selected by increasing the concentration of the drug in the growth medium in a stepwise manner from 0.025 x 10(-6) M up to 12.5 x 10(-6) M. Comparative studies of cellular morphology, cytosolic steroid receptor content and P-Glycoprotein expression were performed on both MCF-7 parental line and MCF-7/MPA variant. MCF-7/MPA cells, when compared to the parental line, exhibit a different morphology in terms of membrane alterations, reduced content of cytosolic progesterone receptor, increased expression of P-glycoprotein along with reduction of Doxorubicin (Dx) activity on the growth of MCF-7/MPA resistant cells
Mobilization, collection, and characterization of peripheral blood hemopoietic progenitors after chemotherapy with epirubicin, paclitaxel, and granulocyte-colony stimulating factor administered to patients with metastatic breast carcinoma
No full textCirculating CD33+ large mononuclear cells contain three distinct populations with phenotype of putative antigene-presenting cells including myeloid dendritic cells and CD14+ monocytes with their CD16+ subset
No full textGoing 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
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