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Objective: To determine the feasibility and effectivity of allogenic frozen-thawed bladder mucosa for urethroplasty. Methods: Bladder mucosa was harvested from 6 New Zealand rabbits. Changes in the bladder mucosa as seen by histological and electron microscope examination were compared between the frozen-thawed and fresh groups. Twelve urethral stricture models were established and randomly divided into two groups. In the test group, we performed urethroplasty with allogenic frozen-thawed bladder mucosa, and the same operation was done in the control group, but using fresh bladder mucosa. The result of retrograde urethrography and histological changes of the urethral sample were compared postoperatively. Results: No obvious changes on histological and electron microscope examination were observed in the frozen-thawed bladder mucosa. Inflammation reaction of the surgical site in the test group was milder than that of the controls 2 weeks after surgery. The urethral epithelial cells grew well 2 weeks after surgery, but lots of epithelia were necrotic in the control group. The urethra of all rabbits in the test group had good continuity and the urethral lumen was large in the test group 2 months after surgery. There was a layer of urethral epithelium in the test group 2 months after surgery, whereas scar tissue was found in the control group. Conclusions: The freeze-thaw technique can maintain bladder mucosa structure and biological function. Frozen-thawed allogenic bladder mucosa may be a potential material for urethroplasty. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Purpose: The aim of the study was to investigate oxidative injury and apoptosis as the mechanisms underlying total parenteral nutrition (TPN)–associated liver dysfunction. Methods: Twenty New Zealand rabbits (2 weeks old) were divided into 2 groups as follows: 10 in the control group (maternal feed) and 10 in the TPN group. The rabbits in the TPN group received continuous PN infusion through a silastic catheter inserted in the right jugular vein. Results: After 10 days of treatment, the serum levels of total bilirubin and bile acid were significantly higher in the TPN group than in the control group (P < .01, respectively). The light microscopic findings in the TPN rabbits included inflammatory cell infiltration and hepatic steatosis. Electron microscopy showed change in the cytosolic vacuoles and rare microvilli in the microbile duct. Moreover, 10 days of treatment resulted in an inhibition of the superoxide dismutase (SOD) activity in hepatocytes, an increase of the malondialdehyde level, a significant increase in cytochrome c release from the mitochondria, a significant increase in caspase 3 activity, and increased apoptosis (P < .01, individually). Conclusions: Oxidative damage may be one of the essential mechanisms of TPN-associated liver dysfunction. Moreover, mitochondria-initiated apoptosis triggered by oxidative damage may play an important role in this process. [Copyright &y& Elsevier]

Autologous tissue transplantation for urethral repair is often limited and causes donor site complications. Here, a cryopreserved rabbit skin epithelial cell sheet (SEC) combined with an acellular amniotic membrane (AM) was used to repair rabbit urethral defects. Abdominal skin was collected from 4-week-old New Zealand rabbits, and primary epithelial cells were extracted and cultured to form a cell sheet. Fresh SEC-AMs were constructed and cryopreserved. A cryopreservation system including optimized medium, two-pump perfusion, a programmed freezer and liquid nitrogen storage was established. Cell viability, mechanical strength, electron microscopy, and histological staining were performed in vitro after 1 month. Next, the sheets were transplanted subcutaneously for 2 weeks, and the graft was used to repair the rabbit urethral defect. Urinary function was measured and samples were collected for histological staining after 1 month. We confirmed that cryopreservation damage of SECs was reduced by composition with acellular AMs in terms of high cell activity. The SEC mechanical strength was also enhanced by AMs, which was convenient for the operation. In in vivo experiments, we transplanted sheets into the groin area for two weeks and found that cryopreservation reduced inflammatory cell infiltration and significantly improved vascular density. In the urethral repair experiment, the near-normal passive urine flow rate, smooth mucosa of the gross specimen, intact epithelialization and abundant neovascularization were confirmed in the cryopreserved-SEC-AM group compared with the other groups. Cryopreserved SEC-AMs demonstrated similar outcomes of rabbit urethral defect repair as fresh SEC-AMs, showing good clinical application prospects. Unlabelled Image • Weak mechanical strength and long culture period are main restraints of cell sheet for urethral reconstruction. • Providing a strategy for skin epithelial cell sheet to achieve off-the-shelf storage • Damage from cryopreservation was reduced by the extracellular matrix of acellular amniotic membrane. • Cryopreserved combination promoted urethral regeneration by regulating macrophage infiltration and polarization. [ABSTRACT FROM AUTHOR]