European validation of the classification for the anticipated difficulty of liver transplantation.

BACKGROUND: Appropriate risk stratification for the difficulty of liver transplantation (LT) is essential to guide the selection and acceptance of grafts and avoid morbidity and mortality. METHODS: Based on 987 LTs collected from 5 centers, perioperative outcomes were analyzed across the 3 difficulty levels. Each LT was retrospectively scored from 0 to 10. Scores of 0-2, 3-5 and 6-10 were then translated into respective difficulty levels: low, moderate and high. Complications were reported according to the comprehensive complication index (CCI). RESULTS: The difficulty level of LT in 524 (53%), 323 (32%), and 140 (14%) patients was classified as low, moderate and high, respectively. The values of major intraoperative outcomes, such as cold ischemia time (p = 0.04) and operative time (p < 0.0001) increased gradually with statistically significant values among difficulty levels. There was a corresponding increase in CCI (p = 0.04), severe complication rates (p = 0.05) and length of ICU (p = 0.01) and hospital (p = 0.004) stays across the different difficulty levels. CONCLUSION: The LT difficulty classification has been validated.

Post-Transplantation Cytomegalovirus Infection Interplays With the Development of Anastomotic Biliary Strictures After Liver Transplantation.

Background: Anastomotic biliary stricture (ABS) remains the most frequent complication after liver transplantation (LT). This study aimed to identify new anastomotic biliary stricture risk factors, with a specific focus on postoperative events. Additionally, ABS management and impact on patient and graft survival were assessed. Methods: All consecutive patients who underwent LT with duct-to-duct anastomosis between 2010 and 2019 were included. All patients who died within 90 days after LT due to non-ABS-related causes were excluded. Results: Among 240 patients, 65 (27.1%) developed ABS after a median time of 142 days (range, 13-1265). Median follow-up was 49 months (7-126). Upon multivariable analysis, donor BMI (OR=0.509, p = 0.037), post-LT CMV primoinfection (OR = 5.244, p < 0.001) or reactivation (OR = 2.421, p = 0.015) and the occurrence of post-LT anastomotic biliary fistula (OR = 2.691, p = 0.021) were associated with ABS. Anastomotic technical difficulty did not independently impact the risk of ABS (OR = 1.923, p = 0.051). First-line ABS treatment was systematically endoscopic (100%), and required a median of 2 (range, 1-11) procedures per patient. Repeat LT was not required in patients developing ABS. The occurrence of ABS was not associated with overall patient survival (p = 0.912) nor graft survival (p = 0.521). Conclusion: The risk of developing ABS after LT seems driven by the occurrence of postoperative events such as CMV infection and anastomotic fistula. In this regard, the role of CMV prophylaxis warrants further investigations.

Fluorescence-based pancreas stump perfusion is associated with postoperative acute pancreatitis after pancreatoduodenectomy a prospective cohort study.

BACKGROUND: Postoperative acute pancreatitis (POAP) emerges as a distinct pancreas-specific complication increasing both the risk and the burden of POPF after pancreatoduodenectomy. Among various risk factors, pancreas stump (PS) hypoperfusion might play a role in POAP occurrence but has never been investigated. The current study aimed at evaluating the feasibility of intraoperative fluorescence angiography (IOFA) of the PS using ICG and its association with POAP. METHODS: Consecutive patients who underwent pancreatoduodenectomy for a periampullary tumor with pancreatojejunostomy and PS perfusion assessment using IOFA between January 2020 and November 2020 were prospectively included. Perioperative management and surgical strategy were standardized. IOFA of the pancreas stump was performed before fashioning pancreatojejunostomy. POAP was defined according to the Connor definition and was confirmed upon radiological blind review. Outcomes between patients with normally perfused and hypoperfused PS were compared. POAP was the primary endpoint. RESULTS: Among 30 patients, nine patients (30%) developed POAP according to the Connor definition, and six patients (20%) had CT-confirmed POAP. Upon IOFA, six patients (20%) presented PS hypoperfusion; of which one patient underwent extended pancreatectomy further to the left. PS hypoperfusion was statistically associated with the occurrence of POAP (80% vs. 16%; p = 0.011) and CT-confirmed POAP (60% vs. 12%; p = 0.041). Clinically relevant POPF rate was 40% in case of PS hypoperfusion and 4% in case of normal PS perfusion (p = 0.064). CONCLUSIONS: PS perfusion assessment using IOFA seems safe and reliable to anticipate POAP. PS IOFA could be considered as a potential tool for perioperative assessment of surgical risk after pancreatoduodenectomy.

Induced pluripotent stem cells-derived neurons from patients with Friedreich ataxia exhibit differential sensitivity to resveratrol and nicotinamide.

Translation of pharmacological results from in vitro cell testing to clinical trials is challenging. One of the causes that may underlie these discrepant results is the lack of the phenotypic or species-specific relevance of the tested cells; today, this lack of relevance may be reduced by relying on cells differentiated from human pluripotent stem cells. To analyse the benefits provided by this approach, we chose to focus on Friedreich ataxia, a neurodegenerative condition for which the recent clinical testing of two compounds was not successful. These compounds, namely, resveratrol and nicotinamide, were selected because they had been shown to stimulate the expression of frataxin in fibroblasts and lymphoblastoid cells. Our results indicated that these compounds failed to do so in iPSC-derived neurons generated from two patients with Friedreich ataxia. By comparing the effects of both molecules on different cell types that may be considered to be non-relevant for the disease, such as fibroblasts, or more relevant to the disease, such as neurons differentiated from iPSCs, a differential response was observed; this response suggests the importance of developing more predictive in vitro systems for drug discovery. Our results demonstrate the value of utilizing human iPSCs early in drug discovery to improve translational predictability.

Protein Kinase-A Inhibition Is Sufficient to Support Human Neural Stem Cells Self-Renewal.

Human pluripotent stem cell-derived neural stem cells offer unprecedented opportunities for producing specific types of neurons for several biomedical applications. However, to achieve it, protocols of production and amplification of human neural stem cells need to be standardized, cost effective, and safe. This means that small molecules should progressively replace the use of media containing cocktails of protein-based growth factors. Here we have conducted a phenotypical screening to identify pathways involved in the regulation of hNSC self-renewal. We analyzed 80 small molecules acting as kinase inhibitors and identified compounds of the 5-isoquinolinesulfonamide family, described as protein kinase A (PKA) and protein kinase G inhibitors, as candidates to support hNSC self-renewal. Investigating the mode of action of these compounds, we found that modulation of PKA activity was central in controlling the choice between self-renewal or terminal neuronal differentiation of hNSC. We finally demonstrated that the pharmacological inhibition of PKA using the small molecule HA1004 was sufficient to support the full derivation, propagation, and long-term maintenance of stable hNSC in absence of any other extrinsic signals. Our results indicated that tuning of PKA activity is a core mechanism regulating hNSC self-renewal and differentiation and delineate the minimal culture media requirement to maintain undifferentiated hNSC in vitro.

Comparison of size, viability, and function of fetal pig islet-like cell clusters after digestion using collagenase or liberase.

Liberase is a highly purified blend of collagenases that has been specifically developed to eliminate the numerous problems associated with the conventional use of crude collagenase when isolating islet-like cell clusters (ICCs) from pancreases of different species. The influence of Liberase on yield, size, viability, and function of ICCs has been documented when this enzyme was used to digest adult but not fetal pancreases. In this study, we compared the effects of collagenase and Liberase on fetal pig ICCs. A total of eight fetal pig pancreas digestions were analyzed. Fetuses were obtained from Large White Landrace pigs of gestational age 80 +/- 2.1 days. The pancreases were digested with either 3 mg/ml collagenase P or 1.2 mg/ml Liberase HI. The time taken to digest the pancreas was shorter for collagenase when compared with Liberase (22 +/- 2 vs. 31 +/- 2 min). The size of ICCs was similar for both collagenase (83 +/- 0.5 microm) and Liberase (79 +/- 0.4 microm) as was the number of ICCs produced per pancreas (7,653 +/- 1,297 vs. 8,101 +/- 1,177). Viability, as assessed using fluorescent markers, was slightly greater for Liberase (79 +/- 1% vs. 76 +/- 1%, p < 0.05). Responsiveness to beta-cell stimulus (20 mM KCl) was similar for both methods of isolation, as was the insulin content of the ICCs, both in vitro and at I month after transplantation of 1,500 ICCs beneath the renal capsule of immunoincompetent mice. Despite the high content of endotoxins in collagenase, the above results show that this enzyme was equally as efficient as Liberase in isolating functional ICCs from fetal pig pancreas.