[Show abstract][Hide abstract] ABSTRACT: PURPOSE: To evaluate the underlying mechanisms by which sevoflurane protects the liver against ischemia/reperfusion injury evaluate the mechanism by which sevoflurane exerts this protective effect. METHODS: Twenty-six rats were subjected to partial ischemia/reperfusion injury for 1h: one group received no treatment, one group received sevoflurane, and sham group of animals received laparotomy only. Four hours after reperfusion, levels of alanine and aspartate aminotransferases, tumor necrosis factor-a, and interleukins 6 and 10 were measured. Analyses of mitochondrial oxidation and phosphorylation, malondialdehyde content, histology, and pulmonary vascular permeability were performed. RESULTS: Serum levels of alanine and aspartate aminotransferases were significantly lower in the sevoflurane group compared to untreated controls (p<0.05). The sevoflurane group also showed preservation of liver mitochondrial function compared to untreated controls (p<0.05). Sevoflurane administration did not alter increases in serum levels of tumor necrosis factor-a, and interleukins 6 and 10. Sevoflurane treatment significantly reduced the coagulative necrosis induced by ischemia/reperfusion (p<0.05). Pulmonary vascular permeability was preserved in the sevoflurane group compared to untreated controls. CONCLUSION: Sevoflurane administration protects the liver against ischemia/reperfusion injury, via preservation of mitochondrial function, and also preserves lung vascular permeability.
Full-text · Article · Nov 2015 · Acta cirurgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia
[Show abstract][Hide abstract] ABSTRACT: Background
Although anorectal transplantation is a challenging procedure, it is a promising option for patients who have completely lost anorectal function or in whom it failed to develop, as in congenital malformations. The paucity of animal models with which to test functional outcomes was addressed in this study of anorectal manometry in rats.Methods
Wistar rats were assigned randomly to four groups: orthotopic anorectal transplantation, heterotopic transplantation, sham operation, or normal control. Bodyweight and anal pressure were measured immediately before and after operation, and on postoperative days 7 and 14. ANOVA and Tukey's test were used to compare results for bodyweight, anal manometry and length of procedure.ResultsImmediately after the procedure, mean(s.d.) anal pressure in the orthotopic group (n = 13) dropped from 31·4(13·1) to 1·6(13·1) cmH2O (P < 0·001 versus both sham operation (n = 13) and normal control (n = 15)), with partial recovery on postoperative day 7 (14·9(13·9) cmH2O) (P = 0·009 versus normal control) and complete recovery on day 14 (23·7(12·2) cmH2O). Heterotopic rats (n = 14) demonstrated partial functional recovery: mean(s.d.) anal pressure was 26·9(10·9) cmH2O before operation and 8·6(6·8) cmH2O on postoperative day 14 (P < 0·001 versus both sham and normal control).Conclusion
Orthotopic anorectal transplantation may result in better functional outcomes than heterotopic procedures.Surgical relevancePatients with a permanent colostomy have limited continence. Treatment options are available, but anorectal transplantation may offer hope. Some experimental studies have been conducted, but available data are currently insufficient to translate into a clinical option. This paper details functional outcomes in a rat model of anorectal autotransplantation. It represents a step in the translational research that may lead to restoration of anorectal function in patients who have lost or have failed to develop it.
Full-text · Article · Feb 2015 · British Journal of Surgery
[Show abstract][Hide abstract] ABSTRACT: The purpose of the present study was to organize the parameters involved in experimental allotransplantation in rodents to elaborate the most suitable model to supply the scarcity of islet donors. We used the PubMed database to systematically search for published articles containing the keywords “rodent islet transplantation” to review. We included studies that involved allotransplantation experiments with rodents’ islets, and we reviewed the reference lists from the eligible publications that were retrieved. We excluded articles related to isotransplantation, autotransplantation and xenotransplantation, i.e., transplantation in other species. A total of 25 studies related to allotransplantation were selected for systematic review based on their relevance and updated data. Allotransplantation in rodents is promising and continues to develop. Survival rates of allografts have increased with the discovery of new immunosuppressive drugs and the use of different graft sites. These successes suggest that islet transplantation is a promising method to overcome the scarcity of islet donors and advance the treatment options for type 1 diabetes.
Full-text · Article · Oct 2014 · World Journal of Gastroenterology
[Show abstract][Hide abstract] ABSTRACT: INTRODUCTION: Autoimmunity and rejection after transplantation must still be overcome in the technical
development of islet transplantation for the treatment of type 1 diabetes. It is therefore necessary to inhibit
rejection of islet grafts while maintaining the graft’s ability to secrete insulin. Although the use of
immunosuppressants reduces the acute rejection rate in transplant patients, long-term side effects must be
OBJECTIVES: The aim of the present study is to organize and analyze the parameters of immunosuppression
involved in experimental attempts of allotransplantation in rodents.
METHODOLOGY: This review was performed using the Pubmed database to search for published articles
containing the keywords “rodent islet transplantation”. The inclusion criteria involved allotransplantation with
rodents’ islets and the reference lists of the publications retrieved that were eligible. The exclusion criteria
involved isotransplantation, autotransplantation, and xenotransplantation such as transplantation in other
RESULTS: Twenty studies related to allotransplantation were selected for this systematic review based on
CONCLUSION: New immunosuppressive drugs increased the survival rates of allotransplantation in rodents by
reducing the side effects. The advances in immunosuppression raise the possibility of overcoming autoimmunity
and rejection after allotransplantation.
KEYWORDS: islet transplantation; allograft; immunosuppressive therapy.
[Show abstract][Hide abstract] ABSTRACT: Background:
Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality worldwide. Chronic hepatitis B infection is associated with an increased risk of cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Our aim is to analyze, through a mathematical model, the potential impact of anti-HBV vaccine in the long-term (that is, decades after vaccination) number of LT.
The model simulated that the prevalence of HBV infection was 0.5% and that approximately 20% of all the liver transplantation carried out in the state of São Paulo are due to HBV infection.
The theoretical model suggests that a vaccination program that would cover 80% of the target population would reach a maximum of about 14% reduction in the LT program.
Increasing the vaccination coverage against HBV in the state of São Paulo would have a relatively low impact on the number of liver transplantation. In addition, this impact would take several decades to materialize due to the long incubation period of liver failure due to HBV.
No preview · Article · Oct 2012 · Clinical Transplantation
[Show abstract][Hide abstract] ABSTRACT: Introduction:
Xenotransplantation is a potential solution for the high mortality of patients on the waiting list for multivisceral transplantation; nevertheless, hyperacute rejection (HAR) hampers this practice and motivates innovative research. In this report, we describe a model of multivisceral xenotransplantation in which we observed immunoglobulin G (IgG) involvement in HAR.
We recovered en bloc multivisceral grafts (distal esophagus, stomach, small intestine, colon, liver, pancreas, and kidneys) from rabbits (n = 20) and implanted them in the swine (n = 15) or rabbits (n = 5, control). Three hours after graft reperfusion, we collected samples from all graft organs for histological study and to assess IgG fixation by immunofluorescence. Histopathologic findings were graded according to previously described methods.
No histopathological features of rejection were seen in the rabbit allografts. In the swine-to-rabbit grafts, features of HAR were moderate in the liver and severe in esophagus, stomach, intestines, spleen, pancreas, and kidney. Xenograft vessels were the central target of HAR. The main lesions included edema, hemorrhage, thrombosis, myosites, fibrinoid degeneration, and necrosis. IgG deposition was intense on cell membranes, mainly in the vascular endothelium.
Rabbit-to-swine multivisceral xenotransplants undergo moderate HAR in the liver and severe HAR in the other organs. Moderate HAR in the liver suggests a degree of resistance to the humoral immune response in this organ. Strong IgG fixation in cell membranes, including vascular endothelium, confirms HAR characterized by a primary humoral immune response. This model allows appraisal of HAR in multiple organs and investigation of the liver's relative resistance to this immune response.
No preview · Article · Sep 2012 · Xenotransplantation
[Show abstract][Hide abstract] ABSTRACT: 13 -REVIEW Review of experimental models for inducing hepatic cirrhosis by bile duct ligation and carbon tetrachloride injection 1 Revisão de modelos experimentais de cirrose hepática induzida por ligadura do ducto biliar e por injeção de tetracloreto de carbono ABSTRACT PURPOSE: To present a review about a comparative study of bile duct ligation versus carbon tetrachloride Injection for inducing experimental liver cirrhosis. METHODS: This research was made through Medline/PubMed and SciELO web sites looking for papers on the content "induction of liver cirrhosis in rats". We have found 107 articles but only 30 were selected from 2004 to 2011. RESULTS: The most common methods used for inducing liver cirrhosis in the rat were administration of carbon tetrachloride (CCl4) and bile duct ligation (BDL). CCl4 has induced cirrhosis from 36 hours to 18 weeks after injection and BDL from seven days to four weeks after surgery. CONCLUSION: For a safer inducing cirrhosis method BDL is better than CCl4 because of the absence of toxicity for researches and shorter time for achieving it. RESUMO OBJETIVO: Apresentar revisão sobre estudo comparativo da indução de cirrose hepática (CH) experimental com a injeção de tetra-cloreto de carbono (CCl4) comparado à ligadura do ducto biliar (BDL). MÉTODOS: A pesquisa foi realizada nas bases de dados do Medline/PubMed e SciELO procurando trabalhos com as palavras indução de CH e ratos. Foram encontrados 107 artigos, mas somente 30 foram selecionados no período de 2004 à 2011. RESULTADOS: Os procedimentos mais comum para indução de CH em ratos foram a injeção de CCl4 e a BDL. O CCl4 induzia CH no período de 36 horas após a injeção e a DBL de sete dias à quatro semanas após a cirurgia. CONCLUSÃO: A BDL é o método mais seguro para indução de CH quando comparado a injeção de CCl4 pela ausência de toxicidade para os pesquisadores e o menor tempo para se obter a lesão hepática.
[Show abstract][Hide abstract] ABSTRACT: The swine is an essential model for carrying out preclinical research and for teaching complex surgical procedures. There is a lack of experimental models describing anatomical and surgical aspects of total pancreatectomy in the pig.
The experiments were performed on 10 white male swine weighing 27-33 kg. The animals were premedicated with midazolam (0.4 mg/kg, i.m.) and ketamine (4 mg/kg, i.m.). Anesthesia was induced with propofol (1-2 mg/kg, i.v.) and was maintained with propofol and fentanyl (0.3 mg and 0.1 μg/kg/min, respectively, i.v.). The surgical period ranged from 44 to 77 min. The pancreas anatomy, and the main arterial, venous and pancreatic duct anatomy were assessed.
The pancreas anatomy was composed of 3 lobes, the 'splenic', 'duodenal' and 'connecting' lobe which is attached to the anterior portion of the portal vein. The splenic artery and the junction of the splenic vein and portal vein were divided. The left gastric artery was dissected and separated from its origin at the splenic artery. The head of the pancreas is disposed in a C shape. The pancreas was dissected and liberated from the right portion of the portal vein and the infrahepatic vena cava. The pancreas was separated from the duodenum preserving the pancreaticoduodenal artery, then we performed the total pancreatectomy preserving the duodenum, common bile duct and spleen.
Total pancreatectomy with duodenum, bile duct and spleen preservation in the pig is feasible and an important instrument for research purposes and teaching surgical technique.
No preview · Article · Jan 2011 · European Surgical Research
[Show abstract][Hide abstract] ABSTRACT: Knowledge of hepatic arterial vascularization and its variations have a significant relevance for the daily practice of hepato-biliary surgeon as well as radiologists. Human cadaver livers (n=60) were obtained from routine autopsies. Resections were carried out en bloc with liver, celiac trunk (CT), left gastric artery (LGA), lesser omentum, superior mesenteric artery (SMA) and head of the pancreas. We have found one case with an exceptional anatomic variation, replaced left hepatic artery (LHA) coming off the SMA directly to the hepatic left lobe. We would like to draw attention for this particularly anatomic variation of the origin of the LHA ensuring that no damage will be made during gastrointestinal surgery.