166 research outputs found

    Engineering an endocrine Neo-Pancreas by repopulation of a decellularized rat pancreas with islets of Langerhans

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    Decellularization of pancreata and repopulation of these non-immunogenic matrices with islets and endothelial cells could provide transplantable, endocrine Neo- Pancreata. In this study, rat pancreata were perfusion decellularized and repopulated with intact islets, comparing three perfusion routes (Artery, Portal Vein, Pancreatic Duct). Decellularization effectively removed all cellular components but conserved the pancreas specific extracellular matrix. Digital subtraction angiography of the matrices showed a conserved integrity of the decellularized vascular system but a contrast emersion into the parenchyma via the decellularized pancreatic duct. Islets infused via the pancreatic duct leaked from the ductular system into the peri- ductular decellularized space despite their magnitude. TUNEL staining and Glucose stimulated insulin secretion revealed that islets were viable and functional after the process. We present the first available protocol for perfusion decellularization of rat pancreata via three different perfusion routes. Furthermore, we provide first proof-of-concept for the repopulation of the decellularized rat pancreata with functional islets of Langerhans. The presented technique can serve as a bioengineering platform to generate implantable and functional endocrine Neo-Pancreata

    The effect of prophylactic treatment with levetiracetam on the incidence of post-attenuation seizures in dogs undergoing surgical management of single congenital extrahepatic portosystemic shunts

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    Objectives: To report (1) the incidence of post-attenuation seizures (PAS) in dogs that underwent single congenital extrahepatic portosystemic shunt (cEHPSS) attenuation and (2) to compare incidence of PAS in dogs that either did or did not receive prophylactic treatment with levetiracetam (LEV).Study Design: Multi-institutional retrospective study.Sample Population: Nine-hundred-and-forty dogs.Methods: Medical records were reviewed to identify dogs that underwent surgical attenuation of a single cEHPSS from January 2005 through July 2017 and developed PAS within seven days postoperatively. Dogs were divided into three groups: no LEV (LEV-); LEV at >15mg/kg TID for >24 hours or a 60mg/kg intravenous loading dose preoperatively, followed by >15mg/kg TID postoperatively (LEV1); ); and LEV at less than 15mg/kg TID, for less than 24 hours preoperatively, or continued at less than 15mg/kg TID postoperatively (LEV2).Results: Nine-hundred-and-forty dogs were included. Seventy-five (8.0%) developed PAS. Incidence of PAS was 35/523 (6.7%), 21/188 (11.2%) and 19/228 (8.3%) in groups LEV-, LEV1 and LEV2, respectively. This difference was not statistically significant (p=0.14). No significant differences between groups of dogs that seized with respect to variables investigated were identified.Conclusions: The overall incidence of PAS was low (8%). Prophylactic treatment with LEV according to the protocols investigated in our study was not associated with a reduced incidence of PAS.Clinical Significance: Prophylactic treatment with LEV does not afford protection against development of PAS. Surgically treated dogs should continue to be monitored closely during the first seven days postoperatively for seizures

    Portal Vein Embolization is Associated with Reduced Liver Failure and Mortality in High-Risk Resections for Perihilar Cholangiocarcinoma

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    Background Preoperative portal vein embolization (PVE) is frequently used to improve future liver remnant volume (FLRV) and to reduce the risk of liver failure after major liver resection. Objective This paper aimed to assess postoperative outcomes after PVE and resection for suspected perihilar cholangiocarcinoma (PHC) in an international, multicentric cohort. Methods Patients undergoing resection for suspected PHC across 20 centers worldwide, from the year 2000, were included. Liver failure, biliary leakage, and hemorrhage were classified according to the respective International Study Group of Liver Surgery criteria. Using propensity scoring, two equal cohorts were generated using matching parameters, i.e. age, sex, American Society of Anesthesiologists classification, jaundice, type of biliary drainage, baseline FLRV, resection type, and portal vein resection. Results A total of 1667 patients were treated for suspected PHC during the study period. In 298 patients who underwent preoperative PVE, the overall incidence of liver failure and 90-day mortality was 27% and 18%, respectively, as opposed to 14% and 12%, respectively, in patients without PVE (p < 0.001 and p = 0.005). After propensity score matching, 98 patients were enrolled in each cohort, resulting in similar baseline and operative characteristics. Liver failure was lower in the PVE group (8% vs. 36%, p < 0.001), as was biliary leakage (10% vs. 35%, p < 0.01), intra-abdominal abscesses (19% vs. 34%, p = 0.01), and 90-day mortality (7% vs. 18%, p = 0.03). Conclusion PVE before major liver resection for PHC is associated with a lower incidence of liver failure, biliary leakage, abscess formation, and mortality. These results demonstrate the importance of PVE as an integral component in the surgical treatment of PHC

    Portal Vein Embolization is Associated with Reduced Liver Failure and Mortality in High-Risk Resections for Perihilar Cholangiocarcinoma

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    Background: Preoperative portal vein embolization (PVE) is frequently used to improve future liver remnant volume (FLRV) and to reduce the risk of liver failure after major liver resection. Objective: This paper aimed to assess postoperative outcomes after PVE and resection for suspected perihilar cholangiocarcinoma (PHC) in an international, multicentric cohort. Methods: Patients undergoing resection for suspected PHC across 20 centers worldwide, from the year 2000, were included. Liver failure, biliary leakage, and hemorrhage were classified according to the respective International Study Group of Liver Surgery criteria. Using propensity scoring, two equal cohorts were generated using matching parameters, i.e. age, sex, American Society of Anesthesiologists classification, jaundice, type of biliary drainage, baseline FLRV, resection type, and portal vein resection. Results: A total of 1667 patients were treated for suspected PHC during the study period. In 298 patients who underwent preoperative PVE, the overall incidence of liver failure and 90-day mortality was 27% and 18%, respectively, as opposed to 14% and 12%, respectively, in patients without PVE (p < 0.001 and p = 0.005). After propensity score matching, 98 patients were enrolled in each cohort, resulting in similar baseline and operative characteristics. Liver failure was lower in the PVE group (8% vs. 36%, p < 0.001), as was biliary leakage (10% vs. 35%, p < 0.01), intra-abdominal abscesses (19% vs. 34%, p = 0.01), and 90-day mortality (7% vs. 18%, p = 0.03). Conclusion: PVE before major liver resection for PHC is associated with a lower incidence of liver failure, biliary leakage, abscess formation, and mortality. These results demonstrate the importance of PVE as an integral component in the surgical treatment of PHC

    Surgery for Bismuth-Corlette Type 4 Perihilar Cholangiocarcinoma: Results from a Western Multicenter Collaborative Group

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    Background Although Bismuth-Corlette (BC) type 4 perihilar cholangiocarcinoma (pCCA) is no longer considered a contraindication for curative surgery, few data are available from Western series to indicate the outcomes for these patients. This study aimed to compare the short- and long-term outcomes for patients with BC type 4 versus BC types 2 and 3 pCCA undergoing surgical resection using a multi-institutional international database. Methods Uni- and multivariable analyses of patients undergoing surgery at 20 Western centers for BC types 2 and 3 pCCA and BC type 4 pCCA. Results Among 1138 pCCA patients included in the study, 826 (73%) had BC type 2 or 3 disease and 312 (27%) had type 4 disease. The two groups demonstrated significant differences in terms of clinicopathologic characteristics (i.e., portal vein embolization, extended hepatectomy, and positive margin). The incidence of severe complications was 46% for the BC types 2 and 3 patients and 51% for the BC type 4 patients (p = 0.1). Moreover, the 90-day mortality was 13% for the BC types 2 and 3 patients and 12% for the BC type 4 patients (p = 0.57). Lymph-node metastasis (N1; hazard-ratio [HR], 1.62), positive margins (R1; HR, 1.36), perineural invasion (HR, 1.53), and poor grade of differentiation (HR, 1.25) were predictors of survival (all p ≤0.004), but BC type was not associated with prognosis. Among the N0 and R0 patients, the 5-year overall survival was 43% for the patients with BC types 2 and 3 pCCA and 41% for those with BC type 4 pCCA (p = 0.60). Conclusions In this analysis of a large Western multi-institutional cohort, resection was shown to be an acceptable curative treatment option for selected patients with BC type 4 pCCA although a more technically challenging surgical approach was required

    A paired-kidney allocation study found superior survival with HLA-DR compatible kidney transplants in the Eurotransplant Senior Program

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    The Eurotransplant Senior Program (ESP) has expedited the chance for elderly patients with kidney failure to receive a timely transplant. This current study evaluated survival parameters of kidneys donated after brain death with or without matching for HLA-DR antigens. This cohort study evaluated the period within ESP with paired allocation of 675 kidneys from donors 65 years and older to transplant candidates 65 years and older, the first kidney to 341 patients within the Eurotransplant Senior DR-compatible Program and 334 contralateral kidneys without (ESP) HLA-DR antigen matching. We used Kaplan-Meier estimates and competing risk analysis to assess all cause mortality and kidney graft failure, respectively. The log-rank test and Cox proportional hazards regression were used for comparisons. Within ESP, matching for HLA-DR antigens was associated with a significantly lower five-year risk of mortality (hazard ratio 0.71; 95% confidence interval 0.53-0.95) and significantly lower cause-specific hazards for kidney graft failure and return to dialysis at one year (0.55; 0.35-0.87) and five years (0.73; 0.53-0.99) post-transplant. Allocation based on HLA-DR matching resulted in longer cold ischemia (mean difference 1.00 hours; 95% confidence interval: 0.32-1.68) and kidney offers with a significantly shorter median dialysis vintage of 2.4 versus 4.1 yrs. in ESP without matching. Thus, our allocation based on HLA-DR matching improved five-year patient and kidney allograft survival. Hence, our paired allocation study suggests a superior outcome of HLA-DR matching in the context of old-for-old kidney transplantation.</p

    Trends in liver transplantation for primary biliary cholangitis in Europe over the past three decades

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    BACKGROUND: The importance of primary biliary cholangitis as an indication for liver transplantation has probably been influenced by the introduction of therapies, and changes in selection criteria and disease epidemiology. AIMS: To assess the time trends in liver transplantation for primary biliary cholangitis and to evaluate the characteristics of the patient population during the past three decades. METHODS: Patients undergoing liver transplantation from 1986 to 2015 in centres reporting to the European Liver Transplantation Registry were included. We excluded combined organ transplantations and patients <18 years. Trends were assessed using linear regression models. RESULTS: We included 112 874 patients, of whom 6029 (5.3%) had primary biliary cholangitis. After an initial increase in the first decade, the annual number of liver transplantation for primary biliary cholangitis remained stable at around 200. The proportion of liver transplantations for primary biliary cholangitis decreased from 20% in 1986 to 4% in 2015 (P < 0.001). Primary biliary cholangitis was the only indication showing a consistent proportional decrease throughout all decades. From the first to the third decade, the age at liver transplantation increased from 54 (IQR 47-59) to 56 years (IQR 48-62) and the proportion of males increased from 11% to 15% (both P < 0.001). CONCLUSIONS: We have found a proportional decrease in primary biliary cholangitis as indication for liver transplantation. However, despite treatment with ursodeoxycholic acid and improved disease awareness, the absolute annual number of liver transplantations has stabilised

    Targeting of Natural Killer Cells by Rabbit Antithymocyte Globulin and Campath-1H: Similar Effects Independent of Specificity

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    T cell depleting strategies are an integral part of immunosuppressive regimens widely used in the hematological and solid organ transplant setting. Although it is known to induce lymphocytopenia, little is known about the effects of the polyclonal rabbit antithymocyte globulin (rATG) or the monoclonal anti-CD52 antibody alemtuzumab on Natural Killer (NK) cells in detail. Here, we demonstrate that induction therapy with rATG following kidney/pancreas transplantation results in a rapid depletion of NK cells. Treatment of NK cells with rATG and alemtuzumab in vitro leads to impairment of cytotoxicity and induction of apoptosis even at a 10-fold lower concentration (0.1 µg/ml) compared with T and B cells. By generating Fc-parts of rATG and alemtuzumab we illustrate that their ligation to FcγRIII (CD16) is sufficient for the significant induction of degranulation, apoptosis and inflammatory cytokine release (FasL, TNFα and IFNγ) exclusively in CD3−CD56dim NK cells whereas application of rATG and alemtuzumab F(ab) fragments abolishes these effects. These findings are of general importance as our data suggest that NK cells are also mediators of the clinically relevant cytokine release syndrome and that their targeting by therapeutic antibodies should be considered as they are functionally relevant for the effective clearance of opportunistic viral infections and anti-tumor activity posttransplantation

    HCC recurrence in HCV-infected patients after liver transplantation: SiLVER Study reveals benefits of sirolimus in combination with CNIs - a post-hoc analysis

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    Factors affecting outcomes in liver transplant (LTx) recipients with hepatocellular carcinoma (HCC) and hepatitis C viral (HCV) infection include the choice of immunosuppression. Here, we analyzed the HCV+ subgroup of patients from the randomized controlled, international SiLVER Study. We performed a post hoc analysis of 166 HCV+ SiLVER Study patients regarding HCC outcome after LTx. Control patients (group A: n&nbsp;=&nbsp;88) received mTOR inhibitor (mTORi)-free, calcineurin inhibitor (CNI)-based versus sirolimus-based immunosuppression (group B: n&nbsp;=&nbsp;78). We found no significant difference regarding HCV-RNA titers between group A and B. Since no effect in group B could be due to variable sirolimus dosing, we split group B into patients receiving sirolimus-based immunosuppression&nbsp;+&nbsp;CNIs for &gt;50% (B1; n&nbsp;=&nbsp;44) or &lt;50% (B2; n&nbsp;=&nbsp;34) of the time. While there remained no difference in HCV-RNA titer between groups, HCC recurrence-free survival in group B1 (81.8%) was markedly better versus both group A (62.7%; P&nbsp;=&nbsp;0.0136) and group B2 (64.7%; P&nbsp;=&nbsp;0.0326); Interestingly, further subgroup analysis revealed an increase (P&nbsp;=&nbsp;0.0012) in liver enzyme values in group B2. Taken together, in HCV-infected patients with HCC and LTx, mTORi immunosuppression&nbsp;+&nbsp;CNIs yields excellent outcomes. Unexpectedly, higher levels of liver inflammation and poorer outcomes occur with mTORi monotherapy in the HCV+ subgroup
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