1,720,965 research outputs found
Acinar cell cystadenocarcinoma of the pancreas: report of rare case and review of the literature
No full textMost exocrine pancreatic tumors are of ductal origin, whereas acinar cell adenocarcinomas are unusual (1% to 2% of all exocrine pancreatic neoplasms). We recently found a cystic adenocarcinoma of the pancreatic body whose cells had the characteristics of acinar cells, which we term acinar cell cystadenocarcinoma. Macroscopically, this tumor consists of a large multilocular cystic mass with a pseudocapsule and a spongy appearance on the cut surface. Microscopically, the cysts are lined by a single layer of cuboid/columnar cells. The cytoplasm has the characteristics of acinar cells, with eosinophilic granules in the apex and prominent nucleoli. Immunohistochemically, the cells express alpha1-antitrypsin, trypsin, and lipase in their cytoplasm, thus confirming the acinar origin of the tumor. A review of the literature revealed only 5 other cases of this tumor reported since its first description in 1981. Follow-up data are available for 4 of these; all of the affected patients had metastases at presentation or a few months later, and 2 died of the disease, at 13 and 37 months after diagnosis. Although this variant of adenocarcinoma of the pancreas is not prognostically different from the classic solid type (few patients survive more than 5 years), we believe that it is important because of its extreme rarity
Well differentiated thyroid carcinoma : new perspectives and old dilemmas
No full textThe diagnosis of well differentiated carcinoma (i.e papillary carcinoma and follicular carcinoma) represents one of the most challenging issue in thyroid pathology. Aim of the present review is to discuss new perspective and old problems in this topic. Three main subjects are developed, corresponding to: 1) the role of fine needle aspiration versus frozen section exami-nation in pre- or peri- operative diagnosis; 2) the management of small papillary tumour; 3) pathological classification of those tumours indeterminate for papillary or follicular nature. There is general agreement that fine needle aspiration represent the best pre-operative diagnostic tool for thyroid nodules; foremost limits are represented by "not diagnostic" and 'follicular lesion, NOS". The former should be repeated or, if suspicious for papillary lesion, improved with intra-operative apposition cytology; the latter should be deferred to histology with frozen section evaluation reserved to those institution with daily practice on this issue. The management of papillary micro-carcinoma (i.e. papillary carcinoma smaller than 1 cm.) in the setting of an otherwise benign thyroid disease is a matter of debate, since several clinicians suggest to consider these as incidental findings thus avoiding additional treatment. Recently this attitude has been supported by the proposal to regard these lesion as tumour" and not carcinoma: available data on follow up seems to sustain and favour this approach. There exist a group of well differentiated tumours of the thyroid lacking the criteria to be diagnosed either as papillary (i.e. nuclear grooves, nuclear pseudo-inclusion and nuclear clearing) or follicular (i.e. capsular or vascular invasion) carcinoma; for these lesion, whose behaviour (nodal or blood metastasis) can not be predicted, it has been suggested the term of well differentiated tumour of uncertain malignant potential. Finally it has to be mentioned the possible role of molecular biology in the diagnosis of well differentiated thyroid carcinoma; indeed markers such as RET/PTC or PAX8/PPARgamma, which to date have been employed mainly in basic research, might represent useful diagnostic (and therapeutic) tools in the future
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
Quantitative PCR and HER2 testing in breast cancer: a technical and cost-effectiveness analysis
No full textWe performed a technical and cost-effectiveness analysis of quantitative reverse transcription- polymerase chain reaction (Q-RT-PCR) for the assessment of HER2 in breast cancer. We evaluated 44 frozen and 55 formalin-fixed paraffin-embedded (FFPE) breast carcinoma specimens by Q-RT-PCR, immunohistochemical analysis, and fluorescent in situ hybridization (FISH). Immunohistochemical and FISH analyses were performed on individual slides and on tissue microarray. Costs of techniques were calculated to study 1 case and 10 or 40 cases. Q-RT-PCR provided reliable data in frozen and FFPE specimens, which were significantly correlated. HER2 messenger RNA levels were significantly stratified in agreement with immunohistochemical data (P < .05). There was complete concordance between Q-RT-PCR and immunohistochemical results for negative and strongly positive (3+) cases. The intermediate immunohistochemical group (2+), including FISH+ and FISH- cancers, could also be stratified by Q-RT-PCR. Cost analysis documented the advantage of Q-RT-PCR in all US Food and Drug Administration - approved assays. Our data support the use of Q-RT-PCR for testing breast cancer specimens to select patients for HER2 inhibitory therapy
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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