1,720,965 research outputs found
Methylation-sensitive high-resolution melting (MS-HRM) analysis in the promoter of MGMT, hMLH1, RASSF1A, CDKN2A genes in colorectal carcinoma
No full textThe evaluation of in vitro cytotoxicity of oxaliplatin and 5-fluorouracil in human colon cancer cell lines: combination versus sequential exposure
No full textQuantification of Blood Dendritic Cells in Colorectal Cancer Patients During the Course of Disease
No full textColorectal cancer is a malignancy with poor prognosis that might be associated with defective immune function. The aim of the present study was to investigate circulating dendritic cells in colorectal cancer patients, in order to contribute to elucidate tumor-escape mechanisms and to point out a possible correlation with the clinical condition of the disease. Therefore, we enumerated ex vivo myeloid and plasmacytoid dendritic cells, through multicolor flow cytometry, in 26 colorectal patients and 33 healthy controls. Furthermore we performed several analyses at determined time points in order to define the immunological trend of cancer patients after surgery and other conventional treatments. At the pre-operative time point the absolute number of plasmacytoid dendritic cells in cancer patients was significantly reduced in comparison to controls, this result being mainly referred to stage III-IV patients. The number of myeloid dendritic cells did not show any significant difference compared to healthy controls; interestingly the expression of the tolerogenic antigen CD85k was significantly higher on cancer patients' myeloid dendritic cells than controls'. At the following samplings, circulating dendritic cell absolute number did not show any difference compared to controls. Conclusively the impairment of the number of circulating dendritic cells may represent one of the tumor escape mechanisms occurring in colorectal cancer. These alterations seem to be correlated to cancer progression. Our work sheds light on one of dendritic cell-based tumor immune escape mechanisms. This knowledge may be useful to the development of more effective immunotherapeutic strategies
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
Determinants of folate metabolism in colorectal cancer patients and healthy individuals
No full textFolate metabolism, a complex pathway required for either the synthesis of DNA precursors or for DNA methylation reactions, has been frequently suggested to play a key role in colorectal cancer (CRC) pathogenesis. In the present study we collected 96 CRC individuals (55 males /41 females, mean age71.04 years) and 96 healthy matched controls (53 males / 43 females, mean age 70.86 years) to further investigate the determinants of folate metabolism in both CRC patients and healthy matched controls. All the individuals have been genotyped for nine biallelic polymorphism of genes involved in folate metabolism (MTHFR 677C > T, MTHFR 1298A > C, MTR 2756A > G, MTRR 66A > G, SLC 19A1 80G > A, TYMS 28bp 2R/3R, TYMS 1494 6bp ins/del, DNMT3B - 579 G > T, DNMT3B - 149C > T). In addition, we also measured plasma homocysteine (hcy), serum folate, and serum vitamin B12 levels in those subjects that were not taking drugs or supplements known to interfere with those parameters.
Multifactorial analysis of variance revealed significantly decreased serum folate (P=0.04)and plasmahcy (P=0.02) levels in CRC patients with respect to healthy matched controls. In addition, vitamin B12 levels had a significant effect on serum folate concentrations (P=0.04), whilst a significant contributor of plasma hcy levels was age at sampling (P=0.0001).
Concerning the polymorphisms of metabolic genes, none of them showed significant different Distributions between CRC patients and healthy controls. However, the MTRR 66A>G polymorphism was associated with serum folate levels in both CRC and healthy individuals (AA vs. GG, PA polymorphism showed a significant correlation with hcy levels in our population (GG vs. AA, PT polymorphism resulted associated with serum vitamin B12 levels (GG vs. GT, P<0.05). Present results suggest that complex interactions among folate, hcy, vitaminB12, and polymorphisms of metabolic genes, superimposed on age related declines, might be responsible of the impairments of folate metabolism in CRC patient
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
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