1,720,962 research outputs found
Pancreatic ductal adenocarcinoma: microenvironment and clinical finding
Get PDFPer poter comprendere i meccanismi alla base dei processi di sviluppo e progressione dell’AdenoCarcinoma dei Dotti Pancreatici (PDAC), particolare attenzione deve essere rivolta al
ruolo del microambiente tumorale. Nel PDAC infatti, le cellule tumorali, piccola porzione della massa tumorale, sono avvolte da un denso stroma circostante che cambia con il progredire del tumore. Recentemente, si è scoperto che le cellule tumorali sono in costante interazione sia tra di loro sia con le diverse componenti del microambiente. Questo continuo scambio di informazioni favorisce la proliferazione, la migrazione e la resistenza ai farmaci chemioterapici delle cellule tumorali. Numerose sono le componenti del microambiente che favoriscono lo sviluppo di tali processi, in particolare il rilascio della chemochina CXCL12 da parte dei fibroblasti associati al tumore (CAF) e il rilascio degli esosomi da parte delle cellule tumorali sembrerebbero essere particolarmente coinvolti nella progressione di questo tumore.
Al fine di individuare possibili bio-marcatori prognostici, in questo studio si è dapprima verificata l'esistenza di correlazioni tra le sottopopolazioni di esosomi rilasciate nel plasma di pazienti PDAC e le loro variabili cliniche. Successivamente si è cercato di determinare il ruolo specifico di ciascuna isoforma di CXCL12 nell’AdenoCarcinoma dei Dotti Pancreatici. In particolare, gli effetti pro-tumorali o anti-tumorali delle isoforme disponibili in commercio, CXCL12-α, CXCL12-β e CXCL12-γ, sono stati valutati sulla linea cellulare pre-tumorale h-Tert HPNE.
Dall’analisi esosomiale è emerso che la proteina EpCAM potrebbe svolgere un ruolo importante come fattore prognostico per il cancro del pancreas. Infatti, alti livelli di espressione della proteina EpCAM, in seguito a chemioterapia, correlano con una migliore sopravvivenza dei pazienti.
Infine, questo lavoro dimostra che sia CXCL12-α che CXCL12-β mostrano un effetto pro-tumorale sulla linea cellulare pre-tumorale pancreatica h-Tert HPNE, poiché inducono un'alterazione in alcuni percorsi coinvolti nei processi di tumorigenesi del carcinoma del pancreas.In order to understand the mechanisms underlying the development and progression processes of Pancreatic Ductal AdenoCarcinoma (PDAC), particular attention must be paid to the role of the tumour microenvironment. In PDAC in fact, the tumour cells, a small portion of the tumour mass, are enveloped by a dense surrounding stroma that changes with the tumour progression. Recently, it has been discovered that cancer cells are in constant interaction both with each other and with the different components of the tumour microenvironment. This continuous exchange of information promotes the proliferation, migration and resistance of cancer cells to chemotherapy drugs. Several components of pancreatic tumour microenvironment favour the development of these processes, in particular the release of the chemokine CXCL12 by tumour-associated fibroblasts (CAF) and the release of exosomes by tumour cells seem to be particularly involved in the progression of this tumour. In order to identify possible prognostic bio-markers, this study first verified the existence of correlations between the subpopulations of exosomes released in the plasma of PDAC patients and their clinical variables. Subsequently an attempt was made to determine the specific role of each isoform of CXCL12 in the Pancreatic Ductal AdenoCarcinoma. In particular, the pro-tumour or anti-tumour effects of commercially available isoforms, CXCL12-α, CXCL12-β and CXCL12-γ, have been evaluated on the pre-tumour cell line h-Tert HPNE. Exosomal analysis has shown that the EpCAM protein could play an important role as a prognostic factor for pancreatic cancer. In fact, high EpCAM expression levels, following chemotherapy, correlate with improved patient survival. Finally, this work shows that both CXCL12-α and CXCL12-β show a pro-tumour effect on the pancreatic pre-tumour cell line h-Tert HPNE, since they induce an alteration in some pathways involved in pancreatic cancer tumorigenesis processes
The Importance of Saliva for Biomolecule Sampling
No full textThe oral compartment is an interesting source of biomolecules that could support or even replace blood sampling. Although having the evident advantage of minimal invasiveness, saliva employment for biomarker recovery did not gain ground because it was believed that only few blood molecules could be recovered from saliva. Recent evidence shows that, not only most blood molecules can be found in saliva but also that in saliva there are molecules not present in blood. Moreover saliva contains molecules coming from distant sites such as exosomes. Here we discuss recent evidence that makes saliva promising for biomarker sampling
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
CXCL12 and Its Isoforms: Different Roles in Pancreatic Cancer?
No full textCXCL12 is a chemokine that acts through CXCR4 and ACKR3 receptors and plays a physiological role in embryogenesis and haematopoiesis. It has an important role also in tumor development, since it is released by stromal cells of tumor microenvironment and alters the behavior of cancer cells. Many studies investigated the roles of CXCL12 in order to understand if it has an anti- or protumor role. In particular, it seems to promote tumor invasion, proliferation, angiogenesis, epithelial to mesenchymal transition (EMT), and metastasis in pancreatic cancer. Nevertheless, some evidence shows opposite functions; therefore research on CXCL12 is still ongoing. These discrepancies could be due to the presence of at least six CXCL12 splicing isoforms, each with different roles. Interestingly, three out of six variants have the highest levels of expression in the pancreas. Here, we report the current knowledge about the functions of this chemokine and then focus on pancreatic cancer. Moreover, we discuss the methods applied in recent studies in order to understand if they took into account the existence of the CXCL12 isoforms
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
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