1,720,961 research outputs found
Pheochromocytoma in Dogs Undergoing Adrenalectomy
No full textPheochromocytoma is frequent in dogs and carries a guarded prognosis. Current histological criteria may not predict malignant behavior in dogs, similar to humans. In humans, characterization of tumors has been refined using the pheochromocytoma of the adrenal gland scaled score (PASS) and by immunohistochemistry. The study aim was to investigate PASS and immunohistochemical markers used in humans in 24 dogs with pheochromocytoma that underwent adrenalectomy. Dogs with pheochromocytomas were reviewed and tumors collected. Histological sections were evaluated to apply the PASS and were single-labeled for chromogranin A, Ki-67, COX-2, p53, BCL-2, c-erbB-2, vascular endothelial growth factor, and S100. Survival, age, and vascular and capsular invasion were compared for PASS and immunohistochemical markers; results of PASS were also compared for each marker. Associations between markers were tested. PASS and immunohistochemical markers did not differ for survival, age, and vascular and capsular invasion. Tumors showing BCL-2 expression in >50% cells had lower PASS than those with lower expression (PASS: 7 ± 2 vs 9 ± 2; P = .011). Tumors positive for S100 had higher PASS than those that were negative (PASS: 10 ± 2 vs 7 ± 2; P = .001). Results of the different markers were not associated. In conclusion, in the context of canine pheochromocytoma, PASS and the selected immunohistochemical markers are not associated with survival, age, or vascular or capsular invasion. The higher PASS in S100-positive tumors may indicate that pheochromocytomas developing morphologic changes acquire S100 expression. The significance of lower PASS in tumors with elevated BCL-2 expression is uncertain. Overall, the use of PASS and the present immunohistochemical markers may not be useful in dogs with pheochromocytoma
Histological and immunohistochemical characterization of feline renal cell carcinoma: a case series
Full text linkFour feline renal cell carcinomas (RCCs) were examined using histopathological and immunohistochemical procedures. Specimens were classified by predominant histological pattern according to WHO criteria. A panel of antibodies including β-catenin, C-KIT, VEGF and VEGF-R2 and double immunostaining for vimentin/cytokeratin and for E-cadherin/CD10 was selected to characterize the tumors. Neoplasms were classified as tubular (3/4) and papillar (1/4). Neoplastic epithelial cells were cytokeratin, vimentin, E-cadherin, VEGF-R2 positive and C-KIT negative; 3 cases were β-catenin positive, whereas only 2 tumors were CD10 and VEGF positive. No correlation with histotype was evident. Our results confirm the low frequency of RCCs in cats and suggest a histological pattern similar to canine RCCs. In contrast, a peculiar immunohistochemical profile different from both canine and human RCCs is identified
Immunohistochemical Expression of E-Cadherin and β-Catenin in Feline Mammary Tumours.
No full textE-cadherin and β-catenin have been studied in carcinogenesis and tumour progression and reduced membrane expression of these molecules in canine mammary tumours has been associated with a poor prognosis. The present study investigated immunohistochemically the expression of E-cadherin and β-catenin in 53 mammary tumours and 48 hyperplastic or dysplastic lesions from 57 queens. E-cadherin and β-catenin expression was membranous in all samples and there was a significant decrease in expression in malignant tumours and metastases. Cytoplasmic expression of both markers was inversely correlated to the membrane localization. β-catenin nuclear labelling was detected in one lymph node metastasis (60% positive cells) and in the basal/myoepithelial cells of 6/7 ductal tumours. No correlation with survival was found for either marker. These results confirm the role of these proteins in maintaining tissue architecture and in inhibiting cell invasiveness and potentially indicate the oncogenic potential of the Wnt/β-catenin transduction pathway in feline mammary tumours. In addition, specific independent expression of β-catenin in the nuclei of basal/myoepithelial cells might suggest that this molecule is involved in regulation of the mammary stem/pluripotent cell component. Further studies should include more cases of benign mammary neoplasia and further investigate β-catenin nuclear expression in ductal tumours
Histological and immunohistochemical characterization of feline renal cell carcinoma: a case series
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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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