Tissue-Engineered External Anal Sphincter Using Autologous Myogenic Satellite Cells and Extracellular Matrix: Functional and Histological Studies.

The aim of the present study was to demonstrate the regaining histological characteristics of bioengineered external anal sphincters (EAS) in rabbit fecal incontinence model. The EAS of 16 rabbits were resected and decellularized. The decellularized scaffolds were transplanted to the terminal rectum following a period of 6 months of fecal incontinency (5 days after sterilization). The rabbits were divided into two groups: in group 1 (n = 8), myogenic satellite cells were injected into the transplanted sphincters. In group 2 (n = 8), the transplanted scaffolds remained in situ without cellular injection. The histological evaluation was performed with desmin, myosin, smooth muscle actin, CD31, and CD34 at 3-month intervals. The rabbits were followed for 2 years. Electromyography (EMG) with needle and electrical stimulation, pudendal and muscle electrical stimulation were also performed after 2 years of transplantation. At the time of biopsy, no evidence of inflammation or rejection was observed and the transplanted EAS appeared histologically and anatomically normal. The immunohistochemistry staining validated that the histological features of EAS was more satisfactory in group 1 in short-term follow-up. However, no statistically significant difference was detected between two groups in long-term follow-ups (p value > 0.05). In both groups, grafted EAS contracted in response to electrical signals delivered to the muscle and the pudendal nerve. However, more signals were detected in group 1 in EMG evaluation. In conclusion, bioengineered EAS with myogenic satellite cells can gain more satisfactory histological outcomes in short-term follow-ups with better muscle electrical stimulation outcomes.

Magnesium protects against bile duct ligation-induced liver injury in male Wistar rats.

The aim of this study was to investigate the effects of magnesium sulfate (MgSO4) on cholestasis-induced hepatic injury after bile duct ligation (BDL) in male Wistar rats. In this study, the effects of 28-day, oral administration of MgSO4 (at doses of 0.01, 0.05, 0.1, and 0.2 g/kg bw) were evaluated in normal and BDL-induced cholestatic rats. The BDL group showed significant increases in serum levels of ALP, ALT, AST, GGT and significant decreases in hepatic SOD and catalase activities. BDL rats also had significant decreases in the serum levels of albumin, bilirubin, total cholesterol, triglycerides, and LDL. Administration of MgSO4 significantly attenuated these changes to nearly normal levels. Administrations of MgSO4 did not change these parameters in normal rats. Histopathological studies further confirmed the protective effects of MgSO4 on cholestasis-induced hepatic injury in the BDL rat model. Taken together, the results of this study suggest that MgSO4 treatment may be beneficial in cholestasis-induced hepatotoxicity.

Hepatoprotective and antifibrotic effects of sodium molybdate in a rat model of bile duct ligation.

PROJECT: Cholestasis liver fibrosis has been increasingly recognized as a cause of high morbidity and mortality in humans. The accumulation of toxic bile salts in a bile duct ligation (BDL) animal model plays a pivotal role in the induction of liver fibrosis. Cholestatic liver fibrosis is characterized by excessive collagen production and deposition, which is mediated by reactive oxygen species (ROS). Molybdenum is an essential micronutrient trace element which acts as a cofactor in many detoxification system enzymes. The aim of the present study was to evaluate the antifibrotic effect of sodium molybdate on liver cholestasis induced by bile duct ligation in rats. PROCEDURE: After BDL, rats were given sodium molybdate (0.05 or 0.1 or 0.2g/kg) or urosodeoxycholic acid (UDCA, 25mg/kg) via intragastric gavage for 45 consecutive days (once per day). RESULTS: BDL drastically increased the serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin and direct bilirubin, whereas it reduced the levels of antioxidant enzymes, superoxide dismutase and catalase in the liver. Treatment of BDL rats with sodium molybdate significantly attenuated these changes. As determined by Masson's trichrome staining, BDL markedly induced the liver fibrosis. These alterations were also significantly attenuated by sodium molybdate administration. CONCLUSIONS: The results of this study indicate the hepatoprotective and antifibrotic effect of sodium molybdate in the cholestatic liver. Sodium molybdate, by inhibiting the activation of Ito cells, decreases the collagen production in the liver. The antifibrotic effect of sodium molybdate is likely due to the antioxidative and free radical scavenging effects of this trace element.

In-vivo trachea regeneration: fabrication of a tissue-engineered trachea in nude mice using the body as a natural bioreactor.

PURPOSE: To investigate the outcomes of implanting rat decellularized trachea scaffold (DTS) between the paravertebral muscles of nude mice using the body as a bioreactor for total graft recellularization. METHODS: The tracheas of four rats were aseptically resected and decellularized. To assess the efficiency of the decellularization procedure, all decellularized scaffolds and native control tissues were evaluated with scanning electron microscopy (SEM), DAPI staining, DNA quantification, biomechanical analyses and hydroxyproline measurement. They were then implanted between the paravertebral muscles of four nude mice. The biopsies were precisely evaluated at 1, 3, 6 and 12 months postoperatively for tracheal cartilage and soft tissue recellularization by staining for TTF1, CD34, S100 and leukocyte common antibody. RESULTS: Hematoxylin and eosin (H&E) staining, SEM and the tensile test confirmed the preservation of the tissue structure and the biophysical and biochemical properties of the DTS. The present study clearly demonstrated that the hydroxyproline content of the DTS was similar to that of the native tissue. On the other hand, in biopsy samples obtained after 12 months, histological evaluation showed superior organization and cell seeding in both the cartilage and connective tissues. CONCLUSION: This study demonstrated the feasibility of using a natural bioreactor for recellularizing DTS; this may have the potential to facilitate homologous transplantation for repairing segmental trachea defects.

Whole-organ tissue engineering: decellularization and recellularization of three-dimensional matrix liver scaffolds.

To report the results of whole liver decellularization by two different methods. To present the results of grafting rat and sheep decellularized liver matrix (DLM) into the normal rat liver and compare natural cell seeding process in homo/xenograft of DLM. To compare the results of in vitro whole liver recellularization with rats' neonatal green fluorescent protein (GFP)-positive hepatic cells with outcomes of in vivo recellularization process. Whole liver of 8 rats and 4 sheep were resected and cannulated via the hepatic vein and perfused with sodium dodecyl sulfate (SDS) or Triton + SDS. Several examinations were performed to compare the efficacy of these two decellularization procedures. In vivo recellularization of sheep and rat DLMs was performed following transplantation of multiple pieces of both scaffolds in the subhepatic area of four rats. To compare the efficacy of different scaffolds in autologous cell seeding, biopsies of homograft and xenograft were assessed 8 weeks postoperatively. Whole DLMs of 4 rats were also recellularized in vitro by perfusion of rat's fetal GFP-positive hepatic cells with pulsatile bioreactor. Histological evaluation and enzymatic assay were performed for both in vivo and in vitro recellularized samples. The results of this study demonstrated that the triton method was a promising decellularization approach for preserving the three-dimensional structure of liver. In vitro recellularized DLMs were more similar to natural ones compared with in vivo recellularized livers. However, homografts showed better characteristics with more organized structure compared with xenografts. In vitro recellularization of liver scaffolds with autologous cells represents an attractive prospective for regeneration of liver as one of the most compound organs. In vivo cell seeding on the scaffold of the same species may have more satisfactory outcomes when compared with the results of xenotransplantation. This study theoretically may pave the road for in situ liver regeneration probably by implantation of homologous DLM or in vitro recellularized scaffolds into the diseased host liver.

Bladder muscular wall regeneration with autologous adipose mesenchymal stem cells on three-dimensional collagen-based tissue-engineered prepuce and biocompatible nanofibrillar scaffold.

OBJECTIVE: Tissue-engineered prepuce scaffold (TEPS) is a collagen-rich matrix with marvelous mechanical properties, promoting in vivo and in vitro tissue regeneration. In this study, adipose-derived mesenchymal stem cells (ADMSCs) were used to seed TEPS for bladder wall regeneration. Its potential in comparison with other materials such as polyglycolic acid (PGA) and nanofibrous scaffolds were evaluated. MATERIALS AND METHODS: Rat ADMSCs were cultured and seeded into prepared TEPS. A synthetic matrix of electrospun nanofibrous polyamide was also prepared. Sprague Dawley rats (n=32) underwent bladder wall regeneration using (a) TEPS, (b) TEPS+PGA, (c) TEPS+nanofibrous scaffold, and (d) ADMSC-seeded TEPS, between bladder mucosa and seromuscular layer. Animals were followed for 30 and 90 days post implantation for evaluation of bladder wall regeneration by determining CD31/34 and SMC α-actin. Cystometric evaluation was also performed in all groups and in four separate rats as sham controls 3 months postoperatively. RESULTS: Histopathological analysis showed well-organized muscular wall generation in ADMSC-seeded TEPS and TEPS+three-dimensional (3D) nanofibrous scaffold without significant fibrosis after 90 days, while mild to severe fibrosis was detected in groups receiving TEPS and TEPS+PGA. Immunohistochemistry staining revealed the maintenance of CD34+, CD31+, and α-SMA in ADMSC-seeded TEPS and TEPS+3D nanofibrous scaffold with significantly higher density of CD34+ and CD31+ progenitor cells in ADMSC-seeded TEPS and TEPS+3D nanofibrous scaffold, respectively. CONCLUSIONS: This work has crucial functional and clinical implications, as it demonstrates the feasibility of ADMSC-seeded TEPS in enhancing the properties of TEPS in terms of bladder wall regeneration.

Augmentation cystoplasty using decellularized vermiform appendix in rabbit model.

PURPOSE: The aim of this study was to produce a decellularized rabbit vermiform appendix (sacculus rotundus) and investigate its feasibility in bladder augmentation or appendicovesicostomy. The superiority of sacculus rotundus over other tissues is its unique mechanical properties as well as its abundant collagen content. MATERIALS AND METHODS: The acellular matrix of vermiform appendix underwent different laboratory investigations prior to transplantation. We divided 12 rabbits into 3 groups: group I underwent bladder augmentation cystoplasty by detubularized acellular matrix. Group II underwent implantation of the tapered (tubularized) acellular matrix just beneath the seromuscular part of the bladder without connection to the bladder urothelium. Group III underwent the same procedure as group II plus reimplantation of tapered and tubularized acellular matrix (simulating an appendicovesicostomy). The distal end of the transplanted graft was connected to the bladder mucosal opening and was intubated by a 5Fr double blind ended feeding tube catheter. Biopsies were taken 3, 12, and 36months post-operatively for further histological and immunohistochemical analyses. RESULTS: The results of the examinations performed prior to transplantation, revealed a decellularized structure resembling the native tissue with intact extracellular matrix, normal pits and appropriate gaps that will be suitable for further cell seeding. Histopathology examination of the biopsies after transplantations confirmed successful cell seeding with urothelial lining in groups I and III, while the inner lumen in group II showed no urothelial lining. CONCLUSION: The results suggest that we can prospect to perform bladder reconstruction by the application of this method without complications of previously reported augmentation cystoplasty. In the current study we used the bladder as a natural bioreactor for autologous recellularization which may pave the road for clinical application in acellular matrix augmentation cystoplasty.

An unusual combination of parathyroid adenoma, medullary and papillary thyroid carcinoma.

The coexistence of medullary thyroid carcinoma (MTC), papillary thyroid carcinoma (PTC) and parathyroid adenoma is an uncommon clinical entity. Here, we report a case of MTC, PTC, and parathyroid adenoma diagnosed incidentally on a routine physical examination of the neck for the work-up of diabetes. The patient had neither symptoms of hypercalcemia nor those related to MTC and PTC.

The ameliorative effect of various antioxidants on Adriamycin-induced fetal renal abnormalities.

OBJECTIVE: To examine the efficacy of nine antiapoptotic compounds in preventing the development of Adriamycin-induced fetal renal abnormalities or ameliorating the resultant renal damage in a rat model. METHODS: Thirty-three Sprague-Dawley rats were randomly divided into sham-control, Adriamycin and prevention groups. The prevention group was divided into 9 subgroups. The rats were time mated and experimental rats were injected with Adriamycin on gestational day 7-9. Sham-control rats were injected with saline on the same days. The preventive medications were administered to the prevention group from 7 days prior to mating to the end of pregnancy. Samples were prepared from fetuses for histological and biochemical analyses. RESULTS: A total of 331 fetuses were recovered. There were no resorptions in the Deferoxamine, Amifostine and sham-control groups. Significant decrease of antioxidant activities was noted in the Adriamycin group compared to the sham-control group. In all prevention groups, antioxidant activities were significantly increased compared to the Adriamycin group. The highest rate of hydronephrosis was observed in the Adriamycin group (82%). The lowest rates of renal abnormalities were noted with Deferoxamine and Amifostine: 8% and 11%. CONCLUSION: Oxidant injury plays a critical role in the development and progression of Adriamycin-induced fetal renal abnormalities. Some antiapoptotic medications, notably Deferoxamine and Amifostine, may have preventive and therapeutic potential in the management of fetal renal abnormalities.

Critical role of Helicobacter pylori in the pattern of gastritis and carditis in residents of an area with high prevalence of gastric cardia cancer.

We have investigated the role of Helicobacter pylori infection and of other risk factors of gastritis and carditis in residents of a high-risk area for gastric cardia cancer. During a national population-based endoscopic survey, 508 randomly-selected participants aged > or =40 were enrolled. Mucosal biopsies were obtained from six standard sites. Polymorphonuclear (PMN) and mononuclear (MN) infiltration and combined inflammatory scores (CIS) for chronic gastritis and H.pylori were assessed. Relationships of H.pylori and reflux esophagitis with these variables were calculated for cardia and non-cardia subsites. Both PMN and MN infiltrations correlated strongly with H.pylori infection. For PMN the relationship was maximum for the antrum (odds ratio (OR) = 9.4 (5.2-17.1)) and minimum for the gastric body (OR = 1.7 (1.0-2.9)). There was a significant relationship between carditis and H.pylori (OR = 2.8 (1.7-4.9)). A similar relationship was obtained for MN infiltration. In 56% of subjects the mean MN score for the corpus was equal to or greater than that for the antrum. For 59% of subjects the MN score for the cardia was greater than or equal to the antral score. Use of logistic regression revealed that was the main risk factor for gastritis and carditis in all sites. There was an inverse relationship between reflux esophagitis and carditis. H.pylori is the main risk factor for gastritis for all sites of the stomach including the cardia; but this relationship is stronger for the antrum and cardia than for the body. Continuous cardia inflammation may contribute to the high incidence of gastric cardia cancer in this region.