1,720,990 research outputs found
Enteropathy-associated T-cell lymphoma.
No full textEnteropathy-associated T-cell lymphoma (EATL) is an intestinal tumour of intraepithelial T lymphocytes, usually presenting as a neoplasm composed of large lymphoid cells and often associated with necrosis and an inflammatory background, including large numbers of histiocytes and eosinophils. Intestinal intraepithelial α-β T-cells have been postulated as the normal-cell counterpart for EATL. EATL is the most common neoplastic complication of coeliac disease. The disease is uncommon in most parts of the world, but is seen with greater frequency in those areas with a high prevalence of coeliac disease, in particular Northern Europe. Usually, EATL occurs in adults, and generally present with abdominal pain, often associated with jejunal perforation, weight loss, diarrhoea, or bowel obstruction. EATL is characterized by multifocal presentation in 10-25% of cases. Small-bowel lymphoma is more common than large-bowel or rectal lymphomas. The prognosis of EATL is very poor, with low chemosensitivity, rapid tumour growth and a tendency to dissemination. Moreover, the high incidence of severe postsurgical complications and the poor nutritional and immunological conditions lead to progressive deterioration of these patients, preventing the use of an adequate and effective treatment
Anaplastic large cell lymphoma, ALK-positive.
No full textAnaplastic large cell lymphoma (ALCL), anaplastic lymphoma kinase (ALK)-positive (ALK+ ALCL) is an aggressive CD30-positive T-cell lymphoma that exhibits a chromosomal translocation involving the ALK gene and the expression of ALK protein. No particular risk factor has been clearly identified for ALCL. ALK+ ALCL shows a broad morphologic spectrum, but all cases contain a variable proportion of cells with eccentric, horseshoe- or kidney-shaped nuclei often with an eosinophilic region near the nucleus (hallmark cells). Five morphologic patterns can be recognized. ALK+ ALCL occurs in young subjects (median age ∼35years), with male predominance, and frequently presents at an advanced stage, with systemic symptoms and extranodal involvement. Near 40% of patients are low risk according to the International Prognostic Index (IPI). Overall, the prognosis of ALK+ ALCL is remarkably better than other T-cell lymphomas. The IPI and the PIT scores in general predict survival in patients with ALK+ ALCL. Standard first-line treatment for ALK+ ALCL consists of doxorubicin-containing polychemotherapy, which is associated with an overall response rate of ∼90%, a 5-year relapse-free survival of ∼60%, and a 5-year overall survival of 70%. Excellent results have been reported with a variety of anthracycline-based chemotherapy regimens including CHOP, CHOEP or MACOP-B. Consolidative high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) has also been evaluated in patients in first remission with favourable results, however, superiority to standard chemotherapy is unproven and this approach remains investigational. Following universally accepted guidelines for the treatment of failed aggressive lymphomas, HDC/ASCT can effectively salvage a proportion of patients with relapsed or refractory ALK+ ALCL. Recently, the development of novel therapies targeting CD30 and ALK appear promising
Hepatosplenic gamma-delta T-cell lymphoma.
No full textHepatosplenic T-cell lymphoma (HSTL) is a rare and aggressive extranodal lymphoma derived mostly from cytotoxic γδ T-cells. The peak incidence is in adolescents and young adults, and is more common in males. Up to 20% of HSTL arise in the setting of chronic immune suppression, most commonly solid organ transplantation or prolonged antigenic stimulation. Patients present with systemic symptoms (fever), abdominal pain, weakness, and marked hepatosplenomegaly in the absence of lymphadenopathy. Patients usually manifest marked thrombocytopenia, often with anaemia and leucopenia, a leukemic phase, and bone marrow involvement in 80% of cases. Lactate dehydrogenase levels are usually markedly elevated. HSTL exhibits a marked chemoresistance to currently used regimens, a rapidly progressive behavior, and dismal prognosis. Patients with post-transplant HSTL exhibit an especially poor outcome. Standard treatment has yet to be established. Anthracycline-based chemotherapy is associated with a satisfactory response in two thirds of patients, but poor long-term results. Complete remission is extremely uncommon, and most patients die from lymphoma within two years of diagnosis. A prognostic correlation between outcome and degree of thrombocytopenia has been reported. Relapsing disease is usually chemorefractory and fast growing, and patients' performance status and clinical conditions are poor. These aspects, as well as the lack of drugs with proven activity against HSTL, render salvage treatment almost impossible. A few cases of HSTL successfully treated with autologous or allogeneic stem-cell transplantation have been reported. The use of 2'-deoxycoformycin and other targeted therapies, such as alemtuzumab, anti-γδ TCR monoclonal antibodies, and anti-CD44 therapy, have shown promising results in anecdotal reports.
Copyright © 2011 Elsevier Ireland Ltd. All rights reserved
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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