1,720,960 research outputs found
Increase of the mitotic activity of colonic mucosa in patients with multiple non-familial adenomatous polyps
No full textA histological study of colonic mucosa, including the measurement of the mitotic index, was performed in routinely processed specimens from control subjects and patients with multiple non-familial adenomatous polyps, to ascertain whether the onset of adenomatous polyps was accompanied by an increase in mucosal mitotic activity as compared with controls. The mitotic index of both the polyps and the mucosa 20 cm from the anal orifice of the same patients was significantly (P less than 0.01) higher than that of control 20 cm from the anal orifice and a shift of the mitotic activity from the lower two-thirds to the upper third of glands was observed in the polyps. These data suggest that an increase of mitotic activity in the superficial third of the glands as compared with controls plays a pathogenetic role in the onset of adenomatous polyps and that this phenomenon is accompanied by a diffuse increase of mitotic activity in the deeper two-thirds of the glands
Increase of the mitotic index of colonic mucosa after cholecystectomy
No full textThis study was undertaken to assess possible modifications of the proliferative activity of colonic mucosa, which could be related to a suggested cancer-promoting role of cholecystectomy. The mitotic index (number of mitoses per 1000 gland cells) was evaluated in the colonic mucosa of 14 healthy subjects, 11 patients with cholelithiasis, before and 6 months after surgery, and 10 patients who had undergone cholecystectomy 2 or more years previously. The mitotic index of cholecystectomized patients was significantly higher than controls. It rose significantly within 6 months of cholecystectomy. The mitotic index of patients with cholelithiasis before surgery was similar to controls. These data suggest that cholecystectomy is followed by an enhancement in the proliferative activity of the colonic mucosa, which could play a cancer-promoting role
Increase of mitotic activity in the colonic mucosa of patients with colorectal cancer
No full textA histologic and histochemical study of the colonic mucosa, including a study of the mitotic index, was performed in routinely processed specimens from control and tumor-bearing patients. A significant increase in the mitotic index (number of mitosis X 1000 gland cells), without concomitant modifications in the distribution of mitotic figures along the crypt depth, in mucosal thickness, or in mucin secretion, was demonstrated in the colonic mucosa of patients with colonic or rectal cancer compared with controls. The results point to an accelerated cell renewal in the colonic mucosa of tumor-bearing patients compared with the controls, without concomitant dysplasia. Results are discussed in the light of the possibility that an increased cell proliferation may have preceded the onset of tumor and played a role in the second step of carcinogenesis, i.e., tumor promotion, independently of dysplasia
Is cholecystectomy a risk factor in the development of gastric neoplasms?]
No full textSome studies suggest cholecystectomy and the cholelithiasic disease are frequently associated to some neoplasms of the digestive tract. Cholecystectomy, through the physiopathologic alterations it causes, seems to assume the role of factor of risk for the development of a gastric neoplasm. The authors reviewed their casuistry by analysing the percentages of subjects in whom the gastric neoplasm was associated to a previous cholecystectomy or a concomitant cholelithiasis. The data obtained do not support the hypothesis that cholecystectomy or the "lithogenicity of the biliary ducts" may be a factor of risk for gastric cancer
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
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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