1,720,964 research outputs found
p120 expression provides a reliable indication of the rapidity of cell duplication in cancer cells independently of tumour origin
No full textp120 is a nucleolar protein that has been immunocytochemically detected in rapidly proliferating cells of a variety of human malignancies. In the present study, the relationship between p120 expression and the rapidity of cell proliferation was evaluated in 48 human tumours of different origins. The cell proliferation rate of cancer cells was determined by quantitative analysis of AgNOR proteins. p120 immunostaining and AgNOR protein quantity,were measured by image cytometry and a highly significant correlation was found between the two variables, as evaluated by linear regression analysis (r = 0.98, p < 0.0001), The relationship between p120 expression and the rapidity of cell duplication was also studied in vitro, in six human cancer cell lines derived from different tumour types, characterized by various doubling times (ranging from 20 to 77 h), p120 expression was determined on western blots using specific anti-p120 monoclonal antibodies. Densitometric analysis revealed a highly significant inverse correlation between the integrated optical density values of the chemoluminescence bands at 120 kD and the cell line doubling times (r = - 0.93; p = 0.007), The same result was obtained bl situ by correlating p120 immunostaining of the cytological preparations obtained from the six cancer cell lines with the corresponding doubling time (r = -0.98, p < 0.0001), These results indicate that in cancer cells, the quantitative expression of p120 is directly related to the rapidity of cell duplication, independently of the tumour origin. Copyrigh
Immunohistochemical detection of nucleolar protein p120 in paraffin-embedded tissues
No full textThe monoclonal antibody FB-2 recognizes the antigen p120-kDa protein (p120), associated with the nucleolar matrix. p120 has originally been reported as expressed and detectable in malignant and non-neoplastic proliferating cells, but not in most normal resting tissues and benign tumours. In the present study, a reliable immunostaining method was used to detect p120 on formalin-fixed, paraffin wax-embedded tissue, testing it on 148 samples from different neoplastic and non-neoplastic tissues from different organs (breast, colon, lung, prostate, bladder, lymph nodes, skin, tongue and liver). The immunostaining was performed after the application of a specific antigen-unmasking protocol based on six consecutive cycles of microwave oven heating. Under these retrieval conditions, p120 antigen was clearly detectable, not only in hyperplastic and malignant cells, but also in stromal and normal non-proliferating cells of all the tissues evaluated. Our results show that the nucleolar protein p120 can be detected by routine immunohistochemistry in formalin-fixed, paraffin-embedded tissue and is expressed in all nucleated cells under any biological condition
Nucleolar hypertrophy correlates with hepatocellular carcinoma development in cirrhosis due to HBV infection
No full textPatients with cirrhosis are at significant risk for hepatocellular carcinoma (HCC). The aim of the present study was to evaluate the relationship between the percentage of hepatocytes showing nucleolar hypertrophy and the development of HCC in cirrhosis of different causes. A total of 111 cirrhotic patients were studied, with a mean follow-up period of 83.3 months. Histologic sections from liver biopsy specimens were silver stained for selective visualization of the nucleolus; the nucleolar area was measured by image cytometry. Nucleoli with a size of 7 microm(2) or greater were considered to be hypertrophic. The nucleolar index was obtained by calculating the percentage of hepatocytes disclosing a nucleolar area of 7 microm(2) or greater. During the observation time, HCC was diagnosed in 39 of 111 patients. The incidence rate of HCC was greater in patients with nucleolar indexes of 2.5 or greater than in patients with nucleolar indexes of less than 2.5 (16.49%/y vs. 3.41%/y, respectively; P <.0001). The capacity of the nucleolar index to predict HCC development was separately tested in groups of patients divided by etiology, and it was found to be particularly relevant in hepatitis B virus (HBV)-related cirrhosis (P =.0006). Among patients with hepatitis C virus (HCV) infection, high nucleolar-index values were associated with a greater risk for HCC development, but the difference in the incidence rate of HCC between groups with a nucleolar index of 2.5 or greater and less than 2.5 was not statistically significant (P =.0944). In conclusion, our results have shown that high percentages of hepatocytes showing nucleolar hypertrophy significantly predict HCC development in patients with HBV infection, whereas their predictive value in HCV-related cirrhosis seems to be lower
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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