1,720,968 research outputs found
Aspetti classificativi, epidemiologici, prognostici e profili di espressione proteica del tumore mammario del cane
Full text linkMammary tumors are the most common neoplasms in female dogs. Available data regarding the etiopathogenesis, the epidemiology and the biological behavior of this type of tumor are still incomplete and controversial. It is widely known that they are highly heterogeneous in morphology and that the lack of precise histopathological diagnostic criteria does not allow an adequate standardization of the diagnosis. Based on these considerations, and as a part of an international collaboration, we studied in details some aspects regarding the classification of these neoplasms. This allowed us to define precise criteria for the distinction between benign and malignant mammary tumors and to write a new classification for the hyperplastic/dysplastic and neoplastic lesions of canine mammary gland. The new classification is a modification of the internationally accepted WHO classification and incorporates some new morphological entities. These standardized criteria were applied on 2143 samples of canine mammary tissue. Other specific morphological characteristics were also evaluated. Relations between all the results obtained, and signalment, and follow-up data were investigated to improve the knowledge about the epidemiology and biological behavior of canine mammary tumors. We noticed that some dog breeds were less represented as carriers of malignant tumors and that in general the incidence of malignant tumor increased with age. In addition, we found that spayed animals, compared to intact ones, tend to have slightly different, apparently more aggressive, mammary tumors. For many tumors subtypes a specific biological behavior was recognized. Of particular interest was the immunohistochemical study of a new tumor subtype (carcinoma and malignant myoepithelioma) characterized by the presence of malignant myoepithelial cells. The prognostic value of different parameters such as tumor diameter, invasion of the lymphatic system, grade of malignancy, presence of peripheral infiltration and of a micropapillary pattern were discussed in details.Il tumore mammario è la neoplasia più frequente nei cani femmina. I dati relativi all’eziopatogenesi, all’epidemiologia e al comportamento biologico di questa forma tumorale sono ancora in parte incompleti e controversi. È risaputo inoltre che tale forma tumorale è caratterizzata da un’elevata eterogeneità morfologica e la mancanza di precisi e definiti criteri diagnostici istopatologici rende spesso difficile un’adeguata standardizzazione nella formulazione della diagnosi. Da queste considerazioni è nata l’esigenza di approfondire alcuni aspetti classificativi nell’ambito di una collaborazione internazionale che ha portato alla definizione di criteri precisi per la distinzione tra forme neoplastiche benigne e maligne e alla stesura di una nuova classificazione per le lesioni iperplastiche/neoplastiche della mammella del cane. Tale classificazione si ispira al precedente sistema classificativo internazionale (WHO), ma risulta rielaborata e integrata con alcune nuove entità morfologiche. Applicando questi criteri e la nuova classificazione su 2143 campioni di tessuto mammario canino e mettendo i risultati ottenuti in relazione ad altre specifiche valutazioni morfologiche e a dati segnaletici e di follow-up è stato possibile mettere in risalto alcuni aspetti, in parte noti e in parte nuovi, relativi all’epidemiologia e al comportamento biologico di questa forma tumorale. Si sono ad esempio messi in evidenza la presenza di razze meno rappresentate tra i soggetti portatori di tumori mammari maligni, un aumento di incidenza delle forme maligne al crescere dell’età e una certa tendenza degli animali sterilizzati, rispetto agli interi, a presentare forme tumorali leggermente diverse, apparentemente più aggressive. Per molte delle tipologie tumorali descritte è stato riconosciuto un comportamento biologico specifico. È stato particolarmente interessante a fini classificativi e prognostici approfondire lo studio, con ausilio immunoistochimico, di una nuova tipologia tumorale (carcinoma e mioepitelioma maligno) caratterizzata dalla presenza di cellule mioepiteliali maligne. È stata inoltre dimostrata o in altri casi confermata e dettagliata, la valenza prognostica di alcuni parametri quali il diametro tumorale, l’invasione del sistema linfatico, il grado istologico di malignità, l’infiltrazione periferica e la presenza di pattern micropapillare
Prognostic Significance of Canine Mammary Tumor Histologic Subtypes: An Observational Cohort Study of 229 Cases
Full text link Histopathology is considered the gold standard diagnostic method for canine mammary tumors. In 2011, a new histologic classification for canine mammary tumors was proposed. The present study was a 2-year prospective study that validated the 2011 classification as an independent prognostic indicator with multivariate analysis in a population of 229 female dogs, identifying subtype-specific median survival times (MST) and local recurrence/distant metastasis rates. Dogs with benign tumors and carcinoma arising in benign mixed tumors all had an excellent prognosis. Dogs with complex carcinoma and simple tubular carcinoma also experienced prolonged survival. Those with simple tubulopapillary carcinoma, intraductal papillary carcinoma, and carcinoma and malignant myoepithelioma had a more than 10-fold higher risk of tumor-related death. The prognosis was even worse for adenosquamous carcinoma (MST = 18 months), comedocarcinoma (MST = 14 months), and solid carcinoma (MST = 8 months). The most unfavorable outcome was for anaplastic carcinoma (MST = 3 months) and carcinosarcoma (MST = 3 months), which also had the highest metastatic rates (89% and 100%, respectively). Adenosquamous carcinoma exhibited the highest local recurrence rate (50%). In the same canine population, the tumor diameter was recognized as a strong predictor of local recurrence/distant metastasis and an independent prognosticator of survival in the multivariate analysis. Excision margins were predictive only of local recurrence, whereas lymphatic invasion and histologic grade were predictive of local recurrence/distant metastasis and survival, although only in univariate analyses. In conclusion, this study validated the 2011 classification scheme and provided information to be used in the clinical setting and as the basis for future prognostic studies. </jats:p
Proposed Classification of the Feline "Complex" Mammary Tumors as Ductal and Intraductal Papillary Mammary Tumors.
Full text linkWhen compared with the canine species, feline mammary tumors (FMTs) are much less heterogeneous, with a predominance of simple malignant neoplasm. Benign FMTs are rare, and it is unclear if complex and mixed tumors exist in the feline. In this study, we selected for immunohistochemical analyses 12 FMTs that had unusual histologic features. A group of 8 (2 benign and 6 malignant) FMTs showed a biphasic epithelial/myoepithelial population and a very regular cord-like distribution in a "Chinese lettering" pattern, within ectatic ducts. A second group (2 benign and 2 malignant) had an intraductal epithelial papillary growth pattern with a basally located monolayer of myoepithelial cells and a supporting fibrovascular stroma. The myoepithelial component always produced a standard immunohistochemical signature. All malignancies were grade I, and the subjects were all alive at 1 year postdiagnosis. On the basis of their morphology, we propose that they be classified as feline ductal adenoma/carcinoma and feline intraductal papillary adenoma/carcinoma, respectively. They overlap with their canine counterparts and lack the typical myoepithelial differentiation patterns seen in canine complex neoplasms, and therefore, the term complex should be avoided in felines. This study will add new information on FMT classification and be useful for prognostic studies
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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