Liver Progenitor Cell Line HepaRG Differentiated in a Bioartificial Liver Effectively Supplies Liver Support to Rats with Acute Liver Failure

A major roadblock to the application of bioartificial livers is the need for a human liver cell line that displays a high and broad level of hepatic functionality. The human bipotent liver progenitor cell line HepaRG is a promising candidate in this respect, for its potential to differentiate into hepatocytes and bile duct cells. Metabolism and synthesis of HepaRG monolayer cultures is relatively high and their drug metabolism can be enhanced upon treatment with 2% dimethyl sulfoxide (DMSO). However, their potential for bioartificial liver application has not been assessed so far. Therefore, HepaRG cells were cultured in the Academic Medical Center bioartificial liver (AMC-BAL) with and without DMSO and assessed for their hepatic functionality in vitro and in a rat model of acute liver failure. HepaRG-AMC-BALs cultured without DMSO eliminated ammonia and lactate, and produced apolipoprotein A-1 at rates comparable to freshly isolated hepatocytes. Cytochrome P450 3A4 transcript levels and activity were high with 88% and 37%, respectively, of the level of hepatocytes. DMSO treatment of HepaRG-AMC-BALs reduced the cell population and the abovementioned functions drastically. Therefore, solely HepaRG-AMC-BALs cultured without DMSO were tested for efficacy in rats with acute liver failure (n = 6). HepaRG-AMC-BAL treatment increased survival time of acute liver failure rats ∼50% compared to acellular-BAL treatment. Moreover, HepaRG-AMC-BAL treatment decreased the progression of hepatic encephalopathy, kidney failure, and ammonia accumulation. These results demonstrate that the HepaRG-AMC-BAL is a promising bioartificial liver for clinical application

Three-dimensional Numerical Modeling and Computational Fluid Dynamics Simulations to Analyze and Improve Oxygen Availability in the AMC Bioartificial Liver

A numerical model to investigate fluid flow and oxygen (O(2)) transport and consumption in the AMC-Bioartificial Liver (AMC-BAL) was developed and applied to two representative micro models of the AMC-BAL with two different gas capillary patterns, each combined with two proposed hepatocyte distributions. Parameter studies were performed on each configuration to gain insight in fluid flow, shear stress distribution and oxygen availability in the AMC-BAL. We assessed the function of the internal oxygenator, the effect of changes in hepatocyte oxygen consumption parameters in time and the effect of the change from an experimental to a clinical setting. In addition, different methodologies were studied to improve cellular oxygen availability, i.e. external oxygenation of culture medium, culture medium flow rate, culture gas oxygen content (pO(2)) and the number of oxygenation capillaries. Standard operating conditions did not adequately provide all hepatocytes in the AMC-BAL with sufficient oxygen to maintain O(2) consumption at minimally 90% of maximal uptake rate. Cellular oxygen availability was optimized by increasing the number of gas capillaries and pO(2) of the oxygenation gas by a factor two. Pressure drop over the AMC-BAL and maximal shear stresses were low and not considered to be harmful. This information can be used to increase cellular efficiency and may ultimately lead to a more productive AMC-BAL

Type 2 Endoleak With or Without Intervention and Survival After Endovascular Aneurysm Repair

Objective: The aims of the present study were to examine the impact of type 2 endoleaks (T2EL) on overall survival and to determine the need for secondary intervention after endovascular aneurysm repair (EVAR). Methods: A multicentre retrospective cohort study in the Netherlands was conducted among patients with an infrarenal abdominal aortic aneurysm (AAA) who underwent EVAR between 2007 and 2012. The primary endpoint was overall survival for patients with (T2EL+) or without (T2EL-) a T2EL. Secondary endpoints were sac growth, AAA rupture, and secondary intervention. Kaplan–Meier survival and multivariable Cox regression analysis were used. Results: A total of 2 018 patients were included. The median follow up was 62.1 (range 0.1 – 146.2) months. No difference in overall survival was found between T2EL+ (n = 388) and T2EL- patients (n = 1630) (p =.54). The overall survival estimates at five and 10 years were 73.3%/69.4% and 45.9%/44.1% for T2EL+/T2EL- patients, respectively. Eighty-five of 388 (21.9%) T2EL+ patients underwent a secondary intervention. There was no difference in overall survival between T2EL+ patients who underwent a secondary intervention and those who were treated conservatively (p =.081). Sac growth was observed in 89 T2EL+ patients and 44/89 patients (49.4%) underwent a secondary intervention. In 41/44 cases (93.1%), sac growth was still observed after the intervention, but was left untreated. Aneurysm rupture occurred in 4/388 T2EL patients. In Cox regression analysis, higher age, ASA classification, and maximum iliac diameter were significantly associated with worse overall survival. Conclusion: No difference in overall survival was found between T2EL+ and T2EL- patients. Also, patients who underwent a secondary intervention did not have better survival compared with those who did not undergo a secondary intervention. This study reinforces the need for conservative treatment of an isolated T2EL and the importance of a prospective study to determine possible advantages of the intervention

Profiling the Impact of Medium Formulation on Morphology and Functionality of Primary Hepatocytes in vitro

The characterization of fully-defined in vitro hepatic culture systems requires testing of functional and morphological variables to obtain the optimal trophic support, particularly for cell therapeutics including bioartificial liver systems (BALs). Using serum-free fully-defined culture medium formulations, we measured synthetic, detoxification and metabolic variables of primary porcine hepatocytes (PPHs) - integrated these datasets using a defined scoring system and correlated this hepatocyte biological activity index (HBAI) with morphological parameters. Hepatic-specific functions exceeded those of both primary human hepatocytes (PHHs) and HepaRG cells, whilst retaining biotransformation potential and in vivo-like ultrastructural morphology, suggesting PPHs as a potential surrogate for PHHs in various biotech applications. The HBAI permits assessment of global functional capacity allowing the rational choice of optimal trophic support for a defined operational task (including BALs, hepatocellular transplantation, and cytochrome P450 (CYP450) drug metabolism studies), mitigates risk associated with sub-optimal culture systems, and reduces time and cost of research and therapeutic applications

Is biliopancreatic diversion with duodenal switch a solution for patients after laparoscopic gastric banding failure?

Background: Weight loss failure after laparoscopic gastric banding (LAGB) can occur in <= 25% of patients. Conversion to a malabsorptive procedure might provide more durable weight loss. The present study evaluated biliopancreatic diversion with duodenal switch (BPD/DS) after LAGB failure with a 3-year follow-up period. Methods: A total of 35 patients underwent BPD/DS after LAGB failure and were prospectively analyzed using a multidisciplinary approach. Weight indexes, co-morbidities, complications, morbidity/mortality, and nutritional status were analyzed. Results: Excess weight decreased from 91% (134 kg, body mass index 48 kg/m(2)) to 75% (124 kg, body mass index 44 kg/m(2)) after LAGB failure and decreased further to 40% (100 kg, body mass index 35 kg/m(2)) after BPD/DS. The mean percentage of excess weight loss was 55% after LAGB and BPD/DS together and 48% after BPD/DS alone. The incidence of co-morbidities, such as diabetes, sleep apnea, hypertension, hyperlipidemia, joint problems, and chronic obstructive pulmonary disease was reduced after BPD/DS. Nutritional deficiencies were already present after LAGB failure (e.g., iron, ferritin, vitamins B-12, B-6, A, D, and E, albumin, and calcium) and either increased (folic acid, potassium, and vitamin B-12), remained stable (iron, ferritin, vitamin A), or decreased after BPD/DS (albumin and vitamins B-6 and E). Conclusion: BPD/DS provided substantial weight loss after LAGB failure and reduced the incidence of obesity-related co-morbidities during a 3-year period. Long-term nutritional follow-up is advocated for all patients after malabsorptive BPD/DS. (Surg Obes Relat Dis 2012;8:393-399.) (c) 2012 American Society for Metabolic and Bariatric Surgery. All rights reserve

Systematic review and meta-analysis of skin substitutes in the treatment of diabetic foot ulcers: Highlights of a Cochrane systematic review

Skin substitutes are increasingly used in the treatment of various types of acute and chronic wounds. The aim of this study was to perform a systematic review and meta-analysis to evaluate the effectiveness of skin substitutes on ulcer healing and limb salvage in the treatment of diabetic foot ulcers. Randomized clinical trials were searched and assessed following the methodology of The Cochrane Collaboration. We included 17 trials, totaling 1655 randomized participants. Risk of bias was variable among included trials. Thirteen trials compared the skin substitutes with standard care. The pooled results showed that that skin substitutes can, in addition to standard care, increase the likelihood of achieving complete ulcer closure compared with standard care alone after 6-16 weeks (risk ratio 1.55, 95% confidence interval [CI] 1.30-1.85). Four of the included trials compared two types of skin substitutes but no particular product showed a superior effect over another. Two trials reported on total incidence of lower limb amputations. Pooling the results of these two trials yielded a statistically significantly lower amputation rate among patients treated with skin substitutes (risk ratio 0.43, 95% CI 0.23-0.81), although the absolute risk difference was small (20.06, 95% CI 20.10 to 20.01). This systematic review provides evidence that skin substitutes can, in addition to standard care, increase the likelihood of achieving complete ulcer closure compared with standard care alone in the treatment of diabetic foot ulcers. However, effectiveness on the long term, including lower limb salvage and recurrence, is currently lacking and cost-effectiveness is unclea

The value of routine ultrasound at discharge to identify patients at risk of developing symptomatic lymphoceles after kidney transplantation: A case-cohort study

Introduction: Ultrasound examination is frequently used to evaluate the graft after renal transplantation and to detect possible lymphoceles. The first ultrasound scan in our hospital is normally performed on the day of discharge. We questioned whether perirenal fluid collections detected by ultrasound examination at discharge are predictive for future symptomatic lymphoceles. Methods: All ultrasound reports of all renal transplant recipients treated in our hospital between January 2010 and December 2017 were collected and screened for abnormalities such as fluid collections. Patients that developed a symptomatic lymphocele were compared with a control group from the same cohort. Sensitivity and specificity of ultrasound examination to detect symptomatic lymphoceles were calculated for the primary and consecutive ultrasounds tests. Results: There were no significant differences at baseline characteristics between the Symptomatic lymphocele group and control group, with the exception of mean age at kidney transplantation (47 &plusmn; 17 years in the control group vs. 56 &plusmn; 13 years in the symptomatic lymphocele group, p=0.02). The ultrasound examination at discharge had a sensitivity of 31% and specificity of 87% to detect future symptomatic lymphoceles. The positive predictive value was only 10%. The second ultrasound test had the best test variables to detect symptomatic lymphoceles with a sensitivity of 93% and a specificity of 87% and a predictive value of 28%. Conclusion: Routinely use of ultrasound testing on the day of discharge does detect perirenal fluid collections, but is not predictive for development of symptomatic lymphoceles in the future

Bioartificial liver: its pros and cons

Both the large variety of liver functions for maintaining body homeostasis and the proven effectivity of whole liver transplantation in the therapy of acute liver failure (ALF), are important reasons to presume that cell-free liver support systems will not be able to adequately support the failing liver. Accordingly, bioartificial liver (BAL) systems have shown their efficacy in experimental ALF models in small and large animals, and have shown to be suitable and safe in phase 1 studies in humans with ALF. However, the optimal BAL system is still under development. Important issues are the source of the cellular component and the configuration of the BAL system with regard to cell attachment, mass transfer characteristics and oxygenation at site. The deficiency of all BAL systems to excrete bile effectively is another important topic for improvement. The great challenge for the future is to develop a well-functioning and safe human hepatic cell line which can replace the widely used porcine (xenogeneic) hepatocytes. Theoretically, a combination of a cell-free liver support system and a BAL system might be optimal for the treatment of ALF patients in the near futur

Extra-hepatic factor VIII expression in porcine fulminant hepatic failure

In humans, fulminant hepatic failure (FHF) is frequently associated with increased factor VIII (FVIII) levels, despite widespread liver cell death. The mechanisms leading to increased FVIII levels and cellular sites of this enhanced FVIII production are poorly understood. We studied the effect of total hepatectomy in pigs, a large-animal model of FHF, on the expression of plasma and tissue FVIII during 24-hour follow-up. Tissue FVIII expression was determined before and 24 h after hepatectomy, both at the mRNA level and immunohistochemically. The expression of plasma and tissue von Willebrand factor (VWF), the natural stabilizing carrier protein of FVIII, was also measured. Total hepatectomy elicited a gradual and sustained twofold elevation of circulating FVIII, whereas FVIII mRNA levels in various organs did not increase after hepatectomy. The half-life of FVIII increased from 7.7 to 10.3 h and VWF levels were also elevated in anhepatic pigs. The increase in the half-life of FVIII and increased levels of VWF were not sufficient to explain the rise in plasma FVIII levels. At the protein level, prominent changes in the cellular distribution of FVIII were seen in spleen and kidney. These observations suggest that in this model of FHF the lack of hepatic FVIII synthesis is adequately compensated by other organs, notably spleen and kidney