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There are few existing methods for shortening the decellularization period for a human-sized whole-liver scaffold. Here, we describe a protocol that enables effective decellularization of the liver obtained from pigs weigh 120 ± 4.2 kg within 72 h. Porcine livers (approx. 1.5 kg) were decellularized for 3 days using a combination of chemical and enzymatic decellularization agents. After trypsin, sodium deoxycholate, and Triton X-100 perfusion, the porcine livers were completely translucent. Our protocol was efficient to promote cell removal, the preservation of extracellular matrix (ECM) components, and vascular tree integrity. In conclusion, our protocol is efficient to promote human-sized whole-liver scaffold decellularization and thus useful to generate bioengineered livers to overcome the shortage of organs.

Assuntos

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INTRODUCTION: Ischemia-reperfusion (I/R) injury of the liver is a common area of interest to transplant and hepatic surgery. Nevertheless, most of the current knowledge of I/R of the liver derives from the hepatocyte and little is known of what happens to the cholangiocytes. Herein, we assess the sequence of early events involved in the I/R injury of the cholangiocytes. METHODS: Sixty Wistar rats were randomized in a SHAM group and I/R group. Serum biochemistry, histopathology, immunohistochemistry, transmission electron microscopy (TEM) and laser capture microdissection (LCM) were used for group comparison. RESULTS: There was peak of alkaline phosphatase 24 h after IR injury, and an increase of aspartate aminotransferase and alanine aminotransferase after 6 h of reperfusion, followed by a return to normal levels 24 h after injury. The I/R group presented the liver parenchyma with hepatocellular degeneration up to 6 h, followed by hepatocellular necrosis at 24 h. TEM showed cholangiocyte injury, including a progressive nuclear degeneration and cell membrane rupture, beginning at 6 h and peaking at 24 h after reperfusion. Cytokeratin-18 and caspase-3-positive areas were observed in the I/R group, peaking at 24-h reperfusion. Anti-apoptotic genes Bcl-2 and Bcl-xl activity were expressed from 6 through 24 h after reperfusion. BAX expression showed an increase for 24 h. CONCLUSIONS: I/R injury to the cholangiocyte occurs from 6 through 24 h after reperfusion and a combination of TEM, immunohistochemistry and LCM allows a better isolation of the cholangiocyte and a proper investigation of the events related to the I/R injury. Apoptosis is certainly involved in the I/R process, particularly mediated by BAX.

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BACKGROUND: In order to simplify a percutaneous gastrostomy procedure and avoid the need of endoscopy or imaging methods, a novel percutaneous magnetically guided gastrostomy (PMG) technique was conceived. The aim of the present study is to evaluate the feasibility of a novel PMG technique with no endoscopy or any imaging guidance in a porcine model. METHODS: Fourteen crossbred domestic pigs were used for prototype development (cadaveric experiments) and proof-of concept, survival study. The magnetic device was conceived using commercially available rare-earth neodymium-based magnets. The experimental design consisted of developing an internal magnetic gastric tube prototype to be orally inserted and coupled to an external magnet placed on the skin, which facilitated stomach and abdominal wall apposition for blind percutaneous gastrostomy tube placement. Then, a gastrostomy tube was percutaneously and blindly placed. RESULTS: Twelve procedures were undertaken in animal cadavers and two in live models. The technique chosen consisted of using a magnetic gastric tube prototype using six 1 × 1-cm-ring magnets attached to its end. This device enabled successful magnetic coupling with a large (5 cm in diameter) magnet disc placed on the skin. For gastric tube placement, a direct trocar insertion allowed easier and safer placement of a gastric tube as compared to a needle-guide-wire dilation (Seldinger-based) technique. Gastropexy was added to avoid early gastric tube displacement. This novel PMG technique was feasible in a live model experiment. CONCLUSIONS: A novel magnetically guided percutaneous gastrostomy tube insertion technique without the use of endoscopy or image-guidance was successful in a porcine model. A non-inferiority experimental controlled study comparing this technique to percutaneous endoscopic gastrostomy is needed to confirm its efficacy and safety.

Assuntos

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BACKGROUND: Few studies have investigated whether quality initiatives in the process of organ donation yield better results of the organ donation process. OBJECTIVE: To analyze whether the indicators of the organ donation process in Brazilian hospitals meet the standards established by the Organ Donation European Quality System (ODEQUS). DESIGN: We evaluated the quality of the organ donation in a selected group of Brazilian hospitals served by the Nucleus of Organ Procurement (NOP) using standards of the ODEQUS. RESULTS: Structural and process indicators had 100% conformity. Indicators of results showed a family consent rate of 61% (29% lower than ODEQUS goal); a conversion rate of potential donors to effective donors of 47% (28% below the goal); and a 12% rate of sudden cardiac arrest (higher than the quality limit). CONCLUSIONS: Our findings highlight the importance for the development of quality initiatives in identifying gaps and weaknesses in the process that should be corrected or even restructured, therefore maximizing the number of donors and organs transplanted. Hospitals that participate in the NOP process met 61% of the quality indicators proposed by ODEQUS. Identification of potential donors, family consent, conversion, and sudden cardiac arrest rates are areas that did not conform to ODEQUS standard and revealed a great opportunity for improvement.

Assuntos