1,720,959 research outputs found
Chemoprevention of Colorectal Cancer in High-Risk Patients: from Molecular Targets to Clinical Trials
No full textAbstract An increased understanding of the molecular pathways
involved in colorectal carcinogenesis has helped researchers
to develop possible chemopreventive strategies.
This has been of particular relevance for high-risk subjects,
for whom chemopreventive strategies may be helpful in
slowing cancer development. In order to obtain more definitive
data on chemopreventive agents, there has been a great
effort to develop preclinical models that resemble the clinical
scenarios encountered in high-risk patients. Importantly, many
compounds, in particular non-steroidal anti-inflammatory
drugs, have shown significant effects in models of highrisk
clinical settings. However, results from clinical trials
have been somewhat disappointing and no definitive
chemopreventative agent is currently given for any of the
high-risk conditions. In this review, we examine the available
data on the effects of chemopreventive drugs on molecular
targets relevant for high-risk conditions predisposing to colorectal
cancer, including data from preclinical studies that have
led to clinical trials
Prevalence of serrated polyposis syndrome in an FIT-based colorectal cancer screening cohort in Italy
Full text linkGoing 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
Chromoendoscopy is not superior to white light endoscopy in improving adenoma detection in Lynch Syndrome cohort undergoing surveillance with high-resolution colonoscopy: a real-world evidence study
No full textBackground: Endoscopic surveillance in patients with Lynch syndrome (LS) is crucial due to a genetically based high risk of colorectal cancer (CRC). We aimed to compare the adenoma detection rate (ADR) between high-resolution white light endoscopy (WLE) alone and WLE plus dye chromoendoscopy (CE) in a cohort of LS patients. Methods: In a context of real-world data, we retrospectively enrolled 50 LS patients who had non-randomly undergone WLE versus CE surveillance examinations from 2007 to 2019. The 2 groups were compared at baseline (BL) in terms of the rate of patients with lesions and the number of lesions, and at follow-up (FU), to evaluate a possible enhanced detection rate. Longitudinal analysis of the effect of the endoscopy type on the main outcomes was performed by generalized linear mixed models. Results: Forty-two patients had undergone at least one diagnostic colonoscopy. At BL and at FU analysis, we found no significant differences in detection rates and clinical-pathological features between WLE and CE groups. At the longitudinal analysis, an increase in the endoscopy rank (i.e., the position of each colonoscopy for all the colonoscopies that a patient had undergone) was associated with an increase in polyp detection rate (p = 0.006) and ADR (p = 0.005), while a trend toward significance (p = 0.069) was found for endoscopy type (CE vs. WLE) in the detection of serrated lesions. Conclusions: CE is not superior to high-resolution WLE in increasing the ADR. Even under standard WLE, an active and careful endoscopic surveillance of LS patients can prevent CRC
Lifestyle factors and risk for colorectal polyps and cancer at index colonoscopy in a FIT-positive screening population
No full textBackground: Many countries have adopted the fecal immunochemical test (FIT) as the primary colorectal cancer (CRC) screening tool; however, its accuracy is limited. Epidemiological studies have shown that obesity and type 2 diabetes increase risk for the disease. Objective: The objective of this article is to evaluate the association of colorectal polyps and cancer with comorbidities and lifestyle factors in a population that is part of a FIT-based CRC screening program. Methods: Between 2005 and 2013, we analyzed 3894 FIT + patients who underwent total colonoscopy. The impact of lifestyle factors on polyps and cancer was assessed using individuals with a negative colonoscopy as the control group. A multivariate logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results: We collected data from 3894 FIT + patients. Obesity (OR 1.29; 95% CI 1.05–1.60) and smoking (OR 1.45; 95% CI 1.24–1.71) were significantly associated with high-risk adenomas. Smoking and heavy alcohol drinking were both independently associated with high risk of CRC (OR 1.50; 95% CI 1.10–2.04 and OR 2.29; 95% CI 1.15–4.58) and colon cancer alone (OR 1.43; 95% CI 1.01–2.02 and OR 3.09; 95% CI 1.53–6.23). Positivity to first round of FIT was associated with high-risk adenomas (OR 1.47; CI 95% 1.26–1.71) and CRC (OR 1.74; 95% CI 1.29–2.36). No associations were found for diabetes. Conclusion: In our FIT + population, lifestyle factors are significantly associated with the risk of carrying high-risk adenomas and CRC. In the future, studies could be aimed at finding better screening strategies through the development of clinical algorithms based on lifestyle changes/comorbidities
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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