1,721,025 research outputs found
ASSOCIAZIONE TRA STATO MUTAZIONALE DI KRAS E PATTERN DI ESPRESSIONE GENETICA NEL CARCINOMA DEL PANCREAS
No full textIntroduzione: Mutazioni attivanti del gene KRAS svolgono un ruolo fondamentale nella carcinogenesi pancreatica. Tuttavia recenti studi hanno dimostrato come la mutazione di KRAS non sia presente in tutti i casi di adenocarcinoma del pancreas, mettendone in discussione l’ubiquità in questa patologia. In questo studio, abbiamo valutato la presenza di differenze a livello molecolare tra adenocarcinomi del pancreas con mutazione di KRAS e senza mutazione; abbiamo valutato inoltre il ruolo prognostico delle diverse mutazioni di KRAS in pazienti affetti da adenocarcinoma pancreatico.
Pazienti e metodi: Abbiamo analizzato l’espressione di un panel di 29 geni in 42 carcinomi pancreatici KRAS wild type (WT) confrontandoli con 42 carcinomi KRAS mutati (MT). Inoltre, abbiamo valutato gli effetti della mutazione di KRAS e dei livelli di espressione genica sulla sopravvivenza dei pazienti.
Risultati: L’analisi di espressione genica ha mostrato che MUC6 (p=0.009), VEGFR-2 (p=0.020), VEGFB (p=0.026) e HGF (p= 0,011) risultavano significativamente più espressi e SMAD4 meno soppresso (p=0.003) nei carcinomi KRAS wild type. Al contrario, SHH (p=0.012) and IHH (p=0.031) sono risultati maggiormente espressi nei tumori KRAS mutati. Non sono state evidenziate differenze significative in termini di sopravvivenza tra pazienti con carcinomi KRAS wild type e mutati o tra le diverse mutazioni di KRAS.
Conclusioni: Lo stato mutazionale di KRAS sembra identificare due sottotipi di adenocarcinoma del pancreas con prognosi simile ma con caratteristiche molecolari distinte e verosimilmente con diversi bersagli molecolari
Panitumumab for the treatment of metastatic colorectal cancer: A review
No full textIn recent years, the treatment of metastatic colorectal cancer (mCRC) has evolved significantly with the increase of new therapeutic options, leading to an improved median survival for these patients. In particular, the identification of molecular targets in tumor cells has led to the introduction of biological drugs for the treatment of mCRC. Panitumumab is a fully human monoclonal antibody that binds the EGF receptor of tumor cells and inhibits downstream cell signaling with antitumor effect on inhibition of tumor growth. Its use has been approved by randomized clinical trials as monotherapy in chemorefractory patients or combined with chemotherapy in the treatment of RAS wild-type mCRC, where it demonstrated a significant improvement in survival and response rate. The purpose of this review is to analyze the use and efficacy profile of panitumumab, particularly focusing on recently reported data on its use, and future perspectives in patients with mCRC
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
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