Morphological and Functional Analysis of Hepatocyte Spheroids Generated on Poly-HEMA-Treated Surfaces under the Influence of Fetal Calf Serum and Nonparenchymal Cells

Poly (2-hydroxyethyl methacrylate) (HEMA) has been used as a clinical material, in the form of a soft hydrogel, for various surgical procedures, including endovascular surgery of liver. It is a clear liquid compound and, as a soft, flexible, water-absorbing material, has been used to make soft contact lenses from small, concave, spinning molds. Primary rat hepatocyte spheroids were created on a poly-HEMA-coated surface with the intention of inducing hepatic tissue formation and improving liver functions. We investigated spheroid formation of primary adult rat hepatocyte cells and characterized hepatic-specific functions under the special influence of fetal calf serum (FCS) and nonparencymal cells (NPC) up to six days in different culture systems (e.g., hepatocytes + FCS, hepatocytes – FCS, NPC + FCS, NPC – FCS, co-culture + FCS, co-culture – FCS) in both the spheroid model and sandwich model. Immunohistologically, we detected gap junctions, Ito cell/Kupffer cells, sinusoidal endothelial cells and an extracellular matrix in the spheroid model. FCS has no positive effect in the sandwich model, but has a negative effect in the spheroid model on albumin production, and no influence in urea production in either model. We found more cell viability in smaller diameter spheroids than larger ones by using the apoptosis test. Furthermore, there is no positive influence of the serum or NPC on spheroid formation, suggesting that it may only depend on the physical condition of the culture system. Since the sandwich culture has been considered a “gold standard” in vitro culture model, the hepatocyte spheroids generated on the poly-HEMA-coated surface were compared with those in the sandwich model. Major liver-specific functions, such as albumin secretion and urea synthesis, were evaluated in both the spheroid and sandwich model. The synthesis performance in the spheroid compared to the sandwich culture increases approximately by a factor of 1.5. Disintegration of plasma membranes in both models was measured by lactate dehydrogenase (LDH) release in both models. Additionally, diazepam was used as a substrate in drug metabolism studies to characterize the differences in the biotransformation potential with metabolite profiles in both models. It showed that the diazepam metabolism activities in the spheroid model is about 10-fold lower than the sandwich model. The poly-HEMA-based hepatocyte spheroid is a promising new platform towards hepatic tissue engineering leading to in vitro hepatic tissue formation

A Service of zbw Leibniz-Informationszentrum Wirtschaft Leibniz Information Centre for Economics -Attribution 4.0 International (CC BY 4.0) Sources of economic growth in MENA countries: A Harrod-neutral technological progress identification framework

Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. countries? Accordingly, this study contributes to the debate over whether the sources of economic growth stem from technological progress, capital or human capital accumulation. Our study finds evidence that economic growth stems from capital accumulation rather than total factor productivity for the MENA countries, except Israel and Saudi Arabia. The authors concluded that assuming the nature of technological progress as Harrod-neutral in growth accounting for the MENA countries does not have a critical impact on the results. Terms of use: Documents in EconStor may JEL O30 O47 O57 C2

Morphological and Functional Analysis of Hepatocyte Spheroids Generated on Poly-HEMA-Treated Surfaces under the Influence of Fetal Calf Serum and Nonparenchymal Cells

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Needle Catheter Jejunostomy in Patients Undergoing Surgery for Upper Gastrointestinal and Pancreato-Biliary Cancer–Impact on Nutritional and Clinical Outcome in the Early and Late Postoperative Period

The metabolic risk for patients undergoing abdominal cancer resection increases in the perioperative period and malnutrition may be observed. In order to prevent further weight loss, the guidelines recommend for high-risk patients the placement of a needle catheter jejunostomy (NCJ) for supplementing enteral feeding in the early and late postoperative period. Our aim was to evaluate the safety of NCJ placement and its potential benefits regarding the nutritional status in the postoperative course. We retrospectively analyzed patients undergoing surgery for upper gastrointestinal cancer, such as esophageal, gastric, and pancreato-biliary cancer, and NCJ placement during the operation. The nutritional parameters body mass index (BMI), perioperative weight loss, phase angle measured by bioelectrical impedance analysis (BIA) and the clinical outcome were assessed perioperatively and during follow-up visits 1 to 3 months and 4 to 6 months after surgery. In 102 patients a NCJ was placed between January 2006 and December 2016. Follow-up visits 1 to 3 months and 4 to 6 months after surgery were performed in 90 patients and 88 patients, respectively. No severe complications were seen after the NCJ placement. The supplementing enteral nutrition via NCJ did not improve the nutritional status of the patients postoperatively. There was a significant postoperative decline of weight and phase angle, especially in the first to third month after surgery, which could be stabilized until 4–6 months after surgery. Placement of NCJ is safe. In patients with upper gastrointestinal and pancreato-biliary cancer, supplementing enteral nutrition during the postoperative course and continued after discharge may attenuate unavoidable weight loss and a reduction of body cell mass within the first six months