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[EN] Pancreatic duct ligation (PDL) in the murine model has been described as an exocrine pancreatic atrophy-inducing procedure. However, its influence has scarcely been described on premalignant lesions. This study describes the histological changes of premalignant lesions and the gene expression in a well-defined model of pancreatic ductal adenocarcinoma by PDL. Selective ligation of the splenic lobe of the pancreas was performed in Ptf1a-Cre((+/ki)); K-ras LSLG12Vgeo((+/ki)) mice (PDL-Kras mice). Three experimental groups were evaluated: PDL group, controls and shams. The presence and number of premalignant lesions (PanIN 1-3 and Atypical Flat Lesions-AFL) in proximal (PP) and distal (DP) pancreas were studied for each group over time. Microarray analysis was performed to find differentially expressed genes (DEG) between PP and PD. Clinical human specimens after pancreaticoduodenectomy with ductal occlusion were also evaluated. PDL-Kras mice showed an intense pattern of atrophy in DP which was shrunk to a minimal portion of tissue. Mice in control and sham groups had a 7 and 10-time increase respectively of risk of high-grade PanIN 2 and 3 and AFL in their DP than PDL-Kras mice. Furthermore, PDL-Kras mice had significantly less PanIN 1 and 2 and AFL lesions in DP compared to PP. We identified 38 DEGs comparing PP and PD. Among them, several mapped to protein secretion and digestion while others such as Nupr1 have been previously associated with PanIN and PDAC. PDL in Ptf1a-Cre((+/ki)); K-ras LSLG12Vgeo((+/ki)) mice induces a decrease in the presence of premalignant lesions in the ligated DP. This could be a potential line of research of interest in some cancerous risk patients.

Purpose: To assess the capacity of two methods of surgical pancreatic stump closure in terms of reducing the risk of pancreatic fistula formation (POPF): radiofrequencyinduced heating versus mechanical stapler. Materials and Methods: Sixteen pigs underwent a laparoscopic transection of the neck of the pancreas. Pancreatic anastomosis was always avoided in order to work with an experimental model prone to pancreatic fistula formation (POPF). Pancreatic stump closure was conducted either by stapler (ST Group, n=8) or radiofrequency energy (RF Group, n=8). Both groups were compared for incidence of POPF and histopathologic alterations of the pancreatic remnant. Results: Six animals (75%) in the ST Group and one (14%) in the RF Group were diagnosed of POPF (p=0.019). One animal in the RF Group and three animals in the ST Group had a pseudocyst in close contact with both pancreas stumps. On day 30 postoperative, almost complete atrophy of the exocrine distal pancreas was observed when the main pancreatic duct was efficiently sealed. Conclusions: Our findings suggest that RF-induced heating is more effective at closing the pancreatic stump than mechanical stapler and leads to the complete atrophy of the distal remnant pancreas.

Irreversible electroporation is a fast-growing liver ablation technique. Although safety has been well documented in small ablations, our aim is to assess its safety and feasibility when a large portion of liver is ablated. Eighty-seven mice were subjected to high voltage pulses directly delivered across parallel plate electrodes comprising around 40% of mouse liver. One group consisted in 55 athymicnude, in which a tumor from the KM12C cell line was grown and the other thirty-two C57-Bl6 nontumoral mice. Both groups were subsequently divided into subsets according to the delivered field strength (1000V/cm, 2000V/cm) and whether or not they received anti-hyperkalemia therapy. Early mortality (less than 24hours post-IRE) in the 2000V/cm group was observed and revealed considerably higher mean potassium levels. In contrast, the animals subjected to a 2000V/cm field treated with the anti-hyperkalemia therapy had higher survival rates (OR=0.1, 95%CI=0.02–0.32, p<0.001). Early mortality also depended on the electric field magnitude of the IRE protocol, as mice given 1000V/cm survived longer than those given 2000V/cm (OR=4.7, 95%CI=1.8–11.8, p=0.001). Our findings suggest that ionic disturbances, mainly due to potassium alterations, should be warned and envisioned when large volume ablations are performed by IRE.

The aim of this study was to assess the capacity of two methods of surgical pancreatic stump closure in terms of reducing the risk of pancreatic fistula formation (POPF): radiofrequency-induced heating versus mechanical stapler. Sixteen pigs underwent a laparoscopic transection of the neck of the pancreas. Pancreatic anastomosis was always avoided in order to work with an experimental model prone to POPF. Pancreatic stump closure was conducted either by stapler (ST group, n = 8) or radiofrequency energy (RF group, n = 8). Both groups were compared for incidence of POPF and histopathological alterations of the pancreatic remnant.

GO-GN is a worldwide network of PhD researchers and their supervisors in the field of OER, MOOCs, and Open Education. It has been initiated in 2012 and is coordinated by the UNESCO Chair in OER at the Open University of the Netherlands. The idea behind GO-GN is to form an alternative for the com- mon situation of individual PhD researchers doing their PhD study in ‘isolation’ at their home universities. GO-GN is linking them as they are based at different universities across country borders, and is offering the opportunity of a broader support and supervision by experts with different backgrounds. Typically a GO-GN PhD researcher will be supervised by a team of three experts from different institutions, chaired by the main supervisor from the PhD degree awarding university. We are facilitating this as we also can assist potential PhD students in search for an appropriate PhD degree awarding university. GO-GN is stimulating the sharing of PhD study practices and experiences and the development of working relations among its PhD researchers and supervisors. And we will guide our members towards courses that can be taken online in order to raise their competencies within the context of their PhD study. This all, of course, related to research in OER, MOOCs, and Open Education.

GO-GN is a worldwide network of PhD researchers and their supervisors in the field of OER, MOOCs, and Open Education. It has been initiated in 2012 and is coordinated by the UNESCO Chair in OER at the Open University of the Netherlands. The idea behind GO-GN is to form an alternative for the com- mon situation of individual PhD researchers doing their PhD study in ‘isolation’ at their home universities. GO-GN is linking them as they are based at different universities across country borders, and is offering the opportunity of a broader support and supervision by experts with different backgrounds. Typically a GO-GN PhD researcher will be supervised by a team of three experts from different institutions, chaired by the main supervisor from the PhD degree awarding university. We are facilitating this as we also can assist potential PhD students in search for an appropriate PhD degree awarding university. GO-GN is stimulating the sharing of PhD study practices and experiences and the development of working relations among its PhD researchers and supervisors. And we will guide our members towards courses that can be taken online in order to raise their competencies within the context of their PhD study. This all, of course, related to research in OER, MOOCs, and Open Education.

[EN] Postoperative pancreatic fistula (PPF) is the most frequent and serious complication after laparoscopic distal pancreatectomy (LDP). Our goal was to compare the performance, in terms of PPF prevention, and safety of a radiofrequency (RF)-assisted transection device versus a stapler device in a porcine LDP model. Thirty-two animals were randomly divided into two groups to perform LDP using a RF-assisted device (RF group; n = 16) and stapler device (ST group; n = 16) and necropsied 4 weeks after surgery. The primary endpoint was the incidence of PPF. Secondary endpoints were surgery/transection time, intra/postoperative complications/deaths, postoperative plasmatic amylase and glucose concentration, peritoneal liquid amylase and interleukin 6 (IL-6) concentrations, weight variations, and histopathological changes. Two clinical and one biochemical PPF were observed in the ST and RF groups respectively. Peritoneal amylase concentration was significantly higher in the RF group 4 days after surgery, but this difference was no longer present at necropsy. Both groups presented a significant decrease in peritoneal IL-6 concentration during the postoperative follow-up, with no differences between the groups. RF group animals showed a higher postoperative weight gain. In the histopathological exam, all RF group animals showed a common pattern of central coagulative necrosis of the parenchymal surface, surrounded by a thick fibrosis, which sealed main and secondary pancreatic ducts and was not found in ST group. The fibrosis caused by an RF-assisted device can be at least as safe and effective as stapler compression to achieve pancreatic parenchyma sealing in a porcine LDP model.