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Sviluppo di biomarkers per la determinazione e la valutazione prognostica della ripresa funzionale epatica post trapianto, nel fegato marginale e nel non heart beating donor
Full text linkABSTRACT
Background
One of the most crucial issues in liver transplantation is the gap between the increasing number of patients waiting for a transplant and the shortage of available grafts. This limitation has led many liver transplant units to include for surgery organs defined as “marginal” or “sub-optimal” due to hepatic steatosis or sourcing from non-heart-beating donors (NHBD). In turn, the marginality of these organ donors is proportional to a high incidence of liver dysfunction after transplantation due mainly to more severe ischemia-reperfusion injury events. The use of new methods of preservation of hepatic grafts like Machine Perfusion becomes necessary, especially for its ability to reduce the damage of ischaemia-reperfusion in hypothermia.
This opens an interest towards the use of alternative methods in preserving hepatic graft as Machine Perfusion, able to reduce this type of insults and allow the dosage of biomarkers that can predict the extent of damage ischemia-reperfusion injury and the quality of functional recovery of the graft after transplantation.
The great potential of this system in the context of organ preservation and the numerous studies in the literature led us to investigate this issue.
Purpose
The aim of our work was to carry out an experimental model of Machine Perfusion (MP) for the preservation of livers procured from non heart-beating donor, as a viable alternative to the traditional Cold storage (CS) at 4°C.
A further aim of our project was to identify biomarkers that can be used as predictors of postoperative graft damage.
Material and methods
We used 10 Landrace pigs of about 20 kg to which we performed, 60 minutes after cardiac arrest, total hepatectomy, thus harvesting the liver. The animals were divided into two groups: in the first group (Group A) 5 livers was preserved for 6 hours in MP at 20° C. In the second group (Group B) 5 livers was stored for 6 hours in CS. In all study groups the period of preservation was followed by reperfusion in normothermic MP (37 °) with whole oxygenated blood previously collected from the donor animal for 2 hours to assess the response to reperfusion. During the experiment blood samples and histological specimens were collected.
Results
Graft preservation by Machin perfusion at 20°C is superior compared to the Cold Storage, both from biochemical (AST, ALT, LDH, lactate) and histological standpoint (necrosis and congestion).
The dose of AST, ALT, LDH and lactate has proven be a reliable parameter for the assessment of organ damage and functional recovery of the graft liver. The dosage of cytokines such as IL1, IL6, TNF alpha showed no significance.
Conclusion
These experimental evidences highlight the effectiveness of a preservation with continuous perfusion at 20° C on a large animal model. Both from biochemical that histological standpoint, we have observed that Machine Perfusion in moderate hypothermia is beneficial in the preservation of the graft and offers the considerable advantage of being able to test, during perfusion, biomarkers that can predict hepatic graft recovery, before transplant, in order to reduce the incidence of post-transplant graft disfunction
GRAFT-RELATED TRANSPLANT BENEFIT BASED ON MELD SCORE OF THE RECIPIENT IN LIVER TRANSPLANTATION
No full textPuò il Sorafenib aprire nuove prospettive come terapia ponte al trapianto di fegato nei pazienti con carcinoma epatocellulare?
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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
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
Case report: Trans-papillary free stenting of the cystic duct and of the common bile duct in a double biliary ducts anastomoses of a right lobe living donor transplantation
Full text linkBackground: One of the major issues related to the living donor liver transplantation recipient outcome is still the
high rate of biliary complication, especially when multiple biliary ducts are present and multiple anastomoses have to
be performed.
Case presentation and conclusion: We report a case of adult-to-adult right lobe living donor liver transplantation
performed for a recipient afected by alcohol-related cirrhosis with MELD score of 17. End-stage liver disease was
complicated by refractory ascites, portal hypertension, small esophageal varices and portal gastropathy, hypersplenism, and abundant right pleural efusion. Here in the attached video we described the adult-to-adult LDLT procedures,
where a right lobe with two biliary ducts draining respectively the right anterior and the right posterior segments
has been transplanted. LDLT required a biliary reconstruction using the native cystic and common bile ducts stented
trans-papillary with two 5- French 6 cm long soft silastic catheter. None major complications were detected during
post-operative clinical courses. Actually, the donor and the recipient are alive and well. The technique we describe in
the video, allow to keep the biliary anastomoses protected and patent without having the risk of creating cholestasis
and the need of invasive additional procedure. No living donor right lobe transplantation should be refused because
of the presence of multiple biliary ducts
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