1,721,176 research outputs found
Mappatura ex vivo dei linfonodi sentinella nei tumori colo-rettali tramite la fluorescenza vicino all'infrarosso con colorante vitale verde di indocianina e sviluppo di nuovi fluorofori
Full text linkIntroduzione
I tumori colo-rettali sono attualmente la seconda causa oncologica di morte per entrambi i sessi. La stadiazione linfonodale è elemento dirimente la stadiazione oncologica e la prognosi dei pazienti, con la conseguente indicazione a trattamenti chemioterapici adiuvanti.
Infatti pazienti con malattia linfonodale negativa (N0) hanno una Overall Survival a 5 anni del 70-80%, contro una percentuale del 30-60% nei pazienti N+ (va precisato però che la sopravvivenza in questo gruppo è migliorata dal trattamento chemioterapico adiuvanti).
Nel 20-30% dei pazienti che presentano recidiva di malattia numerosi autori ipotizzano che questa possa essere dovuta a metastasi linfonodali occulte.
Inoltre nella chirurgia oncologica colorettale, l’identificazione dei linfonodi sentinella permette la ricerca delle micrometastasi tramite la cosiddetta “ultrastadiazione” dei linfonodi campionati con sezioni seriate ed indagini immunoistochimiche o reverse transcriptase-polymerase chain reaction (procedure, per i cui costi e tempi, non applicabili su tutti i linfonodi).
Dai dati riportati in letteratura, è stata evidenziata una prognosi peggiore nei pazienti pN0 affetti da micrometastasi ed è tuttora oggetto di dibattito la chemioterapia adiuvante in questi pazienti.
Il verde indocianina è stato proposto nell’identificazione intraoperatoria dei linfonodi sentinella tramite Fluorescenza vicina all’infrarosso, come già validato nei tumori della mammella e del compartimento testa/collo e nel melanoma cutaneo.
Materiali e metodi
Sono stati inseriti nello studio i pazienti sottoposti a chirurgia colorettale per neoplasia presso il Dipartimento di Chirurgia Generale “P. Stefanini” dell’AOU Policlinico “Umberto I” di Roma e Dipartimento di Chirurgia Generale dell’Ospedale di Fidenza (AUSL di Parma).
Come da protocollo, sul pezzo operatorio a fresco appena resecato, dopo apertura del viscere e identificazione del tumore, viene iniettato 1ml di colorante, su mucosa sana, equidistribuito sui quattro punti cardinali peritumorali. Dopo circa 5-7 minuti vengono identificate e prelevate le sedi di maggior fluorescenza sul tessuto linfoadiposo mesenteriale per essere sottoposte ad esami di ultrastadiazione.
Per ogni paziente inoltre sono stati rilevati i dati dell’esame istologico, in particolare la correlazione con la stadiazione linfonodale in riferimento al linfonodo sentinella
Risultati
Nel corso di questo periodo 58 pazienti sono stati sottoposti a resezioni oncologiche colorettali VLS standard. In ogni paziente è stato identificato almeno 1 SLN. Dal campionamento di tutti pezzi operatori sono stati repertati 1085 linfonodi (117 SLN, media 2.01).
Nei pazienti N0 sono stati trovati trovati 54 SLN (media 1,9).
La detection rate e la sensitivity rate sono state del 94,8% (55/58 pts) e del 100% (30 SLN+ / 30 N+ pts) rispettivamente. La false negative rate è stata dello 0%. In questa serie preliminare, l’assetto istologico dei SLN (sia negli N+ che negli N0) ha correttamente predetto lo stato dei linfonodi loco-regionale.
Dopo gli esami di ultrastadiazione, sono state riscontrate micrometastasi nei SLN N0 in 4 pazienti (14%, 4/28 NND pts) che sono stati così ri-stadiati come N1 ed inviati a trattamento chemioterapico adiuvante.
Conclusioni
Nella nostra serie preliminare, la mappatura NIRF dei SLN con tecnica ex-vivo ha predetto correttamente lo stato linfonodale loco-regionale, come confermato all’esame istologico. L’identificazione delle micrometastasi ha permesso a 4 pazienti precedentemente stadiati come N0 di beneficiare del trattamento chemioterapico adiuvante con l’obiettivo di ridurre il rischio di recidiva. Il colorante vitale verde di indocianina però risulta non ottimale per la ricerca dei linfonodi sentinella e vi è la necessità di sviluppare e testare nuovi fluorofori, nuovi software e hardware per migliorare, nel futuro, le mappature linfonodali
Cholangiocarcinoma: Challenges and future needs
No full textCholangiocarcinoma (CCA) is a malignant neoplasm that
arises from the biliary tract epithelia. CCA is the second most
common primary liver tumour after hepatocellular carcinoma,
representing 10-25% of primary hepatic malignancies (1).
CCA is rare in many parts of the world, such as Europe and
the United States (US), accounting for <3% of all malignant
tumours. However, there is a dramatic geographic variation in its
incidence, which reflects regional differences in risk factors and
epidemiology (2,3)
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
Prevention of hepatitis C recurrence after liver transplantation: An update.
No full textHepatitis C related liver failure and hepatocarcinoma are the most common indications for liver transplantation in Western countries. Recurrent hepatitis C infection of the allograft is universal and immediate following liver transplantation, being associated with accelerated progression to cirrhosis, graft loss and death. Graft and patient survival is reduced in liver transplant recipients with recurrent Hepatitis C virus (HCV) infection compared to HCV-negative recipients. Many variables may impact on recurrent HCV liver disease. Overall, excess immunosuppression is believed to be a key factor; however, no immunosuppressive regimen has been identified to be more beneficial or less harmful. Donor age limitations, exclusion of moderately to severely steatotic livers and minimization of ischemic times could be a potential strategy to minimize the severity of HCV disease in transplanted subjects. After transplantation, antiviral therapy based on pegylated IFN alpha with or without ribavirin is associated with far less results than that reported for immunocompetent HCV-infected patients. New findings in the field of immunotherapy and genomic medicine applied to this context are promising
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
Liver transplantation in a patient with complete portal vein thrombosis, is there a surgical way out? A case report
Full text linkIntroduction: Due to the complexity of the surgical procedure portal vein thrombosis (PVT) has long been considered an absolute contraindication to liver transplantation (LT). The presence of a large splenorenal shunt (SRS) could make portal anastomosis a valid option.Presentation of case: We report the case of a 37-year-old female patient with Grade III PVT and a large SRS, who underwent orthotopic LT. Liver was implanted using a 1992-Belghiti piggyback technique and portal anastomosis was performed using the large spleno-renal shunt. We observed good graft reperfusion and postoperative Doppler ultrasound showed normal portal vein flow. She was discharged on postoperative day 7, with an excellent graft function. At six months follow-up, patient is alive with normal hepatic vascularization.Discussion: Due to paucity of reports, there is currently no consensus on the indication to LT and/or surgical technique. In the present case, once the transplant benefit was evaluated, the Grade III PVT was not considered a contraindication to LT.Conclusion: The presence of a Grade III PVT associated with a large SRS should not be considered a contraindication for LT, and the use of the shunt vein should be considered a feasible option to perform portal anastomosis. (C) 2016 The Author(s). Published by Elsevier Ltd on behalf of IJS Publishing Group Ltd
Effetti dell'acido tauroiodesossicolico sulla secrezione biliare: studio sperimentale strutturale, ultrastrutturale e biochimico.
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