1,720,954 research outputs found
Application of Comparative Genomic Hybridization (CGH) for response prediction of rectal adenocarcinoma to preoperative chemoradiotherapy
No full textAdenokarzinme des Rektums gehören zu den häufigsten Tumoren der westlichen Welt. In fortgeschrittenen Stadien (UICC II/III) ist die neoadjuvante Radiochomotherapie, gefolgt von radikaler Chirurgie Standard. Allerding reicht das Spektrum des Ansprechens von kompletter Remission bis kompletter Resistenz. Ziel dieser Arbeit war es daher auf chromosomaler Ebene Biomarker zur prätherapeutischen Einschätzung und Therapieplanung zu finden. Wir untersuchten 42 Patienten mit rektalen Karzinomen der UICC-Stadien II und III. Alle neoadjuvant auf Basis von 5-FU radiochemotherapiert. Jeweils 21 Responder und 21 Non-responder mittels Comparativer Genomischer Hybridisierung (CGH). Als Definition von Respons wählten wir die T-Level Reduktion. Der Vergleich der beiden Gruppen zeigte, dass Responder signifikant häufiger (p<0,05) Zugewinne der chromosomalen Regionen 7q32-q36, 7q11-7q31 und Amplifikationen der Region 20q11-20q13 aufweisen. Es ist allerdings (bei einem p-Wert von 0,21) vom aktuellen Standpunkt gesehen unsicher, ob diese genomischen Veränderungen tatsächlich biologische Unterschiede zwischen den beiden Gruppen charakterisieren oder lediglich Artefakte darstellen.Introduction - Standard treatment of rectal cancer patients in UICC stages II and III comprises preoperative chemoradiotherapy followed by radical surgery. But there is a wide spectrum of tumor responsiveness, ranging from complete response to complete resistance. The aim of this study was to find predictive biomarkers, helpful for optimal individual therapy. Materials and Methods - Pre therapeutic biopsies of 42 patients, treated with 5-FU based preoperative chemoradiotherapy, because of locally advanced rectal cancer were analyzed by metaphase comparative genomic hybridization to prospectively identify genomic imbalances that might assist in stratifying tumors into responsive or non-responsive. Results Tumors were later divided into two Groups. 21 rectal cancers were classified as responsive, while 21 were non-responsive, based on T-Level-down-sizing. We could show that gains of chromosomal regions 7q32-q36 and 7q11-q31, and amplifications of 20q11-q13 were significantly associated with responsiveness to preoperative chemoradiotherapy (P<0.05). However, the probability to detect these copy number changes by chance is high (P=0.21). Conclusion - Pre-therapeutic evaluation of chromosomal copy number changes may be of value for response prediction of rectal cancers to preoperative chemoradiotherapy. Regarding our results we cannot reject the possibility that these three chromosomal aberrations were discovered by random chance. (P=0.21)
Chromosomal copy number changes of locally advanced rectal cancers treated with preoperative chemoradiotherapy
No full textStandard treatment of rectal cancer patients comprises preoperative chemoradiotherapy followed by radical surgery. However, clinicians are faced with the problem that response rates vary from one individual to another. Predictive biomarkers would therefore be helpful. To identify genomic imbalances that might assist in stratifying tumors into responsive or nonresponsive categories, we used metaphase comparative genomic hybridization to prospectively analyze pretherapeutic biopsies from 42 patients with locally advanced rectal cancers. These patients were subsequently treated with 5-fluorouracil-based preoperative chemoradiotherapy. Based on downsizing of the T-category, 21 rectal cancers were later classified as responsive, while the other 21 were nonresponsive. Comparing these two groups, we could show that gains of chromosomal regions 7q32 similar to q36 and 7q11 similar to q31, as well as amplifications of 20q11 similar to q13, were significantly associated with responsiveness to preoperative chemoradiotherapy (P < 0.05). However, the probability of detecting these copy number changes by chance is high (P = 0.21). Our primary results suggest that pretherapeutic evaluation of chromosomal copy number changes may be of value for response prediction of rectal cancers to preoperative chemoradiotherapy. This will require validation in a larger cohort of patients. (C) 2009 Elsevier Inc. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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