1,720,957 research outputs found
Differential responsiveness of proliferation and cytokeratin release to stripped serum and oestrogen in the human breast cancer cell line, MCF-7.
No full textIn vitro research into hormone sensitivity and the relation to proliferation of cytokeratin release from cancer cells is scarce. Therefore, we examined the stimulation of proliferation and the release of cytokeratins in a breast cancer cell culture model. Cell growth was stimulated by 17 beta-oestradiol (10(-11) M), stripped serum (10%) and by the two together. Cytokeratin release was stimulated only by stripped serum, oestradiol having no effect. After long incubation periods (> 12 h), cytokeratin release also commenced in the control and oestradiol treatments. Release rate versus time analysis suggested that there are two different release processes. Cytokeratin release was first stimulated at a stripped serum concentration approximately 100 times lower than that which initiated proliferation. Pharmacological alteration of proliferation with cordyceptin resulted in growth changes without alterations in cytokeratin release. We conclude that cytokeratin release in these cells is unrelated to proliferation, independent of oestrogen action and probably in some way related to growth factor receptor function
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
Association of pS2 (TFF1) release with breast tumor proliferative rate: in vitro and clinical evidence
No full textAlthough cytosolic expression of the protein pS2 (TFF1) is considered to be a marker of oestrogen receptor (OR) function, there exists some clinical data to suggest an inverse relationship of cytosolic pS2 to tumour proliferation. Although secreted from breast cancer cells, the relationship of pS2 secretion to tumour natural history has been little studied. The mechanisms and kinetics of pS2 release and its relation to tumour cell proliferation were studied in a human breast cancer cell line MCF-7 and verified in a preliminary clinical study. Stimulation by stripped serum or oestradiol resulted in parallel increases of proliferation and pS2 release in both time course and dose-response experiments. Direct pharmacological alterations of proliferation were followed by identical changes in pS2 release. The relationship between serum pS2 levels and tumour proliferative activity when analysed as a function of steroid status showed a slope of 0.56 in OR+ vs. 0.19 in OR- tumours. It is concluded that pS2 release from breast cancer cells is associated with their proliferation and measurement of serum pS2 levels might be a good predictor of tumour proliferative state and could permit noninvasive monitoring of this tumour parameter
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
Cytokeratins and proliferation in breast cancer patients.
No full textTissue polypeptide antigen (TPA) was studied in 242 sera and 165 tumor cell cytosols (both evaluations in 67 cases) of breast cancer patients, for which proliferative activity, determined by the TLI technique, was also available. The TPA serum and tumor cell cytosol median values (utilized for measure analysis as cut-off) were 70 U/1 and 377 U/mg cytosol protein, respectively. High serum TPA levels were associated with unfavourable clinicopathological characteristics whereas a higher tumor cell cytosol TPA level was associated with better cytohistological tumor differentiation. Furthermore, no overall correlation was found between serum and tumor cell cytosol TPA levels or between their levels and TLI. When analyzing cases in which serum and tumor cell cytosol TPA values were higher than 100 U/l and 500 U/mg cytosol protein, respectively (n = 28), serum TPA was positively associated with TLI (slope = 12.3 r = 0.55, p < 0.01), while cytosolic TPA resulted negatively associated with TLI (slope = -87.4 r = 0.41, p < 0.01). Finally, a strong inverse relationship between cytosolic and serum TPA (p < 0.0005) became evident. We suggest that TPA could represent a serum marker for tumor cell proliferation in specific patient subgroups with original high serum and/or cytosol TPA expression
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
Cathepsin D, an acidic aspartyl protease, is associated with and facilitates human cancer cell invasion
No full textDispelling 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
- …
