1,720,961 research outputs found
Lower- and higher-grade subtypes of diffuse gastric cancer
No full textDiffuse gastric cancer, characterized by poorly cohesive, diffusely infiltrating cells with no or little gland formation, is known to show several morphologic variants, but their prognostic value, if any, is poorly documented. In this article, 119 cases of invasive (T1b to T4) diffuse gastric cancer, which had undergone potentially curative surgery and were followed postoperatively for a median time of more than 10 years, were investigated for histologic or histochemical patterns possibly predictive of survival. Among 5 histologic groups identified, a low-grade subtype (17 cases) with prominent desmoplasia closely surrounding individual tumor cells (tumor embedding desmoplasia) and no or scarce angio-lympho-neuroinvasion showed stage-independent improved survival compared with 36 non-low-grade desmoplastic, 24 signet ring, and 28 diffuse cancers not otherwise specified. Fourteen cases with anaplastic cells showed clinicopathologic patterns and outcome of highly malignant neoplasms. None of the tumor cell differentiation markers (including 6 mucins and 3 proteases) nor proliferative index or p53 protein expression had independent predictive power, although MUC1 was significantly less expressed in low-grade desmoplastic cases. Cox survival analysis showed the significantly better prognosis of 17 low-grade desmoplastic and worse prognosis of 14 anaplastic cancers compared with the remaining 88 cases. In conclusion, a low-grade desmoplastic and a high-grade anaplastic subtype should be separated histologically from the bulk of diffuse gastric cancers owing to their distinctive histologic, clinicopathologic, and prognostic aspects
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
Intracellular, Intercellular, and Stromal Invasion of Gastric Mucosa, Preneoplastic Lesions, and Cancer by Helicobacter pylori
No full textBACKGROUND AND AIMS: It is not clear how Helicobacter pylori, an apparently extracellular pathogen colonizing the luminal side of the gastric epithelium, invariably causes an immune-inflammatory response on the stromal side of the mucosa. Penetration of H pylori into epithelial cell lines and its interaction with immune-inflammatory cells have been documented in vitro. Several investigations also showed in vivo bacterial penetration into the epithelium up to the lamina propria; however, the identification as H pylori of the bacteria-like bodies observed in unchanged, metaplastic, or neoplastic mucosa remained sometimes questionable.
METHODS: To search for bacteria-like organisms, we used transmission electron microscopy on endoscopic biopsy specimens from 20 dyspeptic subjects and surgical specimens of neoplastic and nonneoplastic mucosa from 20 cancerous stomachs. To ascertain the H pylori nature of the organisms found, we used 6 different antibodies directed against bacterial lysates, purified vacuolating cytotoxin A, or purified cytotoxin-associated antigen A in immunogold tests. The results were compared with those of H pylori strains cultivated in vitro.
RESULTS: In nonmetaplastic gastric epithelium, cytochemically proven H pylori were detected, in the majority of cases, inside cytoplasm of epithelial cells, in intraepithelial intercellular spaces, and in underlying lamina propria, often in direct contact with immune-inflammatory cells and sometimes inside small blood vessels. Cytochemically proven H pylori were also observed inside 6 of 8 intestinal metaplasias and 9 of 20 cancers.
CONCLUSIONS: H pylori penetrates normal, metaplastic, and neoplastic gastric epithelium in vivo, intracellularly, or interstitially to cause a strong immune-inflammatory response and promote gastric carcinogenesis
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
IDENTIFICATION OF A LOWER GRADE MUCONODULAR SUBTYPE OF GASTRIC MUCINOUS CANCER.
No full textUntil now, survival analysis of gastric mucinous cancers showed either no difference or an even worse prognosis than stage-adjusted non-mucinous tumours. In the pancreas and breast, mucinous cancers showing well-demarcated mucin deposits (muconodular pattern), expansile growth and predominance of MUC2 mucin are known to have a more favourable prognosis. In this study, an attempt was made to separate, among 41 gastric mucinous cancers, a subgroup of tumours with muconodular expansile pattern, possibly predictive of a more favourable outcome. A group of 15 tumours was identified, which were characterised by overwhelming (80-100%) mucinous component, predominance of mucus over tumour cells inside muconodules, moderately aggressive growth of their epithelial component (reduced proliferative rate, moderate anaplasia, lack of angioinvasion and limited lymphoinvasion) and dominant expression of intestinal goblet cell markers, with special reference to MUC2 mucin. Univariate and multivariate survival analysis showed a significantly improved outcome of these lower grade muconodular tumours compared with the remaining mucinous cancers as well as with non-mucinous cancers of cohesive, diffuse (signet-ring cell included) and undifferentiated high-grade types
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
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