1,720,984 research outputs found
Association between preoperative Vasostatin-1 and pathological features of aggressiveness in localized nonfunctioning pancreatic neuroendocrine tumors (NF-PanNET)
No full textBackground: A reliable and accessible biomarker for nonfunctioning pancreatic neuroendocrine tumors (NF-PanNET) is currently unavailable. Chromogranin A (CgA) represents the best-described neuroendocrine biomarker, but its accuracy is low. Vasostatin-1 (VS-1), a fragment derived from the cleavage of CgA, was recently investigated and found to be more accurate as tumor biomarker in a cohort of patients affected by mainly metastatic small intestinal NET. Methods: Patients submitted to surgery for sporadic localized NF-PanNET at San Raffaele Hospital were included. Preoperative plasma samples were prospectively collected. Circulating levels of total-CgA and VS-1 were retrospectively investigated by sandwich Enzyme-Linked ImmunoSorbent Assays. Results: Overall, 50 patients were included. VS-1 value (P=0.0001) was the only preoperatively retrievable factor independently associated with NF-PanNET size. No significant correlation between CgA and tumor diameter was found (P = 0.057). A VS-1 value of 0.39 nM was identified as the optimal VS-1 cut-off accurately associated with NF-PanNET larger than 4 cm. Patients with VS-1 > 0.39 nM had a significantly higher frequency of microvascular invasion (P = 0.005) and nodal metastasis (P = 0.027). Median VS-1 plasma level was significantly higher in the presence of microvascular invasion (P = 0.001) and nodal metastasis (P = 0.012). PPI assumption significantly increased total-CgA levels, but not those of VS-1 (P = 0.111). Conclusions: In localized, non-metastatic NF-PanNET, VS-1 is strongly associated to tumor dimension and its plasma levels are significantly higher in the presence of microvascular invasion and nodal metastases; moreover, VS-1 value is not affected by the PPI use
How to Select Patients Affected by Neuroendocrine Neoplasms for Surgery
No full textPurpose of Review The aim of this review was to discuss how to select patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) for surgery. Recent Findings Surgical resection represents the mainstay for the curative treatment of GEP-NENs. Conservative strategies, such as endoscopic resection and active surveillance, have been recently advocated for the management of patients with small and asymptomatic GEP-NENs. On the other hand, patients with GEP-NENs showing features of aggressiveness should be managed by surgical resection with lymphadenectomy, when the surgical risk is considered acceptable. An accurate selection is important also in the setting of advanced disease, where surgery can provide a survival benefit in the context of a multimodal treatment strategy. Surgical and oncological risk should be always assessed in order to define indications for surgery in patients with GEP-NENs. Given the variety of available treatment options, surgical indication should be always shared with a dedicated multidisciplinary team
Exploring definitions of graft pancreatitis following pancreas transplantation: A scoping review
No full text: Despite the clinical relevance of graft pancreatitis (GP) after pancreas transplantation (PT), a universally accepted definition is lacking. Aim of this scoping review was to provide a systematic overview of GP definitions reported in the literature. MEDLINE, Web of Science and Embase were searched for relevant articles. Prospective/retrospective studies reporting a GP definition were included. The included series (n = 20) used four main criteria (clinical, biochemical, radiological and pathological) to define GP. Overall, 9 studies defined GP using a single criterion (n = 8 biochemical, n = 1 pathological), 7 series using two criteria (n = 3 clinical + biochemical, n = 3 biochemical + radiological, n = 1 clinical + radiological), 3 series using three criteria (n = 3 clinical + biochemical + radiological), and 1 series using four criteria. Overall, 20 definitions of GP were found. GP rate was reported by 19 series and ranged between 0% and 87%. This scoping review confirms that a universally accepted definition of GP is absent, and there is no consensus on the criteria on which it should be grounded. Future research should focus on developing a validated definition of GP
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
Long-Term Pancreatic Functional Impairment after Surgery for Neuroendocrine Neoplasms
No full textRadical surgery represents the only curative treatment for pancreatic neuroendocrine neoplasms (PanNEN). The aim of this study was to evaluate the postoperative onset of diabetes mellitus (DM) and/or pancreatic exocrine insufficiency (PEI) in surgically treated PanNEN. Consecutive PanNEN patients, without preoperative DM, who underwent partial pancreatic resection, were included. After a median follow-up of 72 months, overall 68/276 patients (24%) developed DM. Patients who developed DM were significantly older (p = 0.002) and they had a higher body mass index (BMI) (p < 0.0001) than those who did not; they were more frequently male (p = 0.017) and with nonfunctioning neoplasms (p = 0.019). BMI > 25 Kg/m2 was the only independent predictor of DM (p = 0.001). Overall, 118/276 patients (43%) developed a PEI, which was significantly more frequent after pancreaticoduodenectomy (p < 0.0001) and in patients with T3-T4 tumors (p = 0.001). Pancreaticoduodenectomy was the only independent predictor of PEI (p < 0.0001). Overall, 54 patients (20%) developed disease progression. Patients with and without DM had similar progression free survival (PFS), whereas patients without PEI had better five-year-PFS (p = 0.002), although this association was not confirmed in multivariate analysis. The risk of DM and PEI after surgery for PanNEN is relatively high but it does not affect PFS. BMI and pancreatic head resection are independent predictors of DM and PEI, respectively
Diagnostic accuracy of EUS-FNA in the evaluation of pancreatic neuroendocrine neoplasms grading: Possible clinical impact of misclassification
No full textBackground and Objectives: Prognosis of pancreatic neuroendocrine neoplasms (PanNENs) mostly depend on tumor stage and grade, determined by Ki-67 labeling index. EUS-FNA is considered the gold-standard technique to obtain it. The aims of our study were to establish diagnostic accuracy of preoperative EUS-FNA Ki-67 evaluation considering final pathological assessment on surgical specimen as gold standard and to investigate the possible impact on prognosis of misclassification. Methods: This is a retrospective study from a prospectively collected database. EUS-FNA grading (eG) and surgical one (sG) measured according to Ki-67 proliferative index values, according to 2017 WHO classification, were compared. eG-sG correlation was evaluated by Spearman index. Logistic regression investigated factors associated with misclassification. Prognostic difference in terms of progression-free survival was evaluated by Kaplan Meier method. Results: One hundred and twelve PanNENs patients enrolled. In 13.4% of patients (15/112) EUS-FNA "undergraded" patients (eG1 vs. sG2), while in 12.5% (n = 14) it "overgraded" PanNENs (eG2 to sG1). No misclassifications in G3 patients. In patients with tumors <20 mm (n = 44), 2 (4.5%) eG1 and 10 (22.7%) eG2 were finally classified respectively as G2 and G1 at surgical histology. No factors, as i.e. the lesions' size or their morphological aspect, were associated with misclassification. In overgraded PanNENs, no progression occurred, while in patients correctly classified/undergraded the progression rate was 14.3%. Conclusions: This is the largest cohort of surgical PanNENs with preoperative EUS-FNA grading evaluation. Despite an acceptable eG-sG correlation, about 25% of patients are misclassified. Clinical impact of misclassification should be carefully considered especially in small tumors undergoing observation
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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