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Graft Reperfusion (graft + reperfusion)
Selected AbstractsHigh mobility group box 1 protein as a marker of hepatocellular injury in human liver transplantationLIVER TRANSPLANTATION, Issue 10 2008Minna Ilmakunnas High mobility group box 1 protein (HMGB1), a cytokine actively secreted by phagocytes and passively released from necrotic cells, is an inflammatory mediator in experimental hepatic ischemia/reperfusion injury. We characterized its expression in human liver transplantation. In 20 patients, in addition to systemic samples, blood was drawn from portal and hepatic veins during and after reperfusion to assess changes within the graft. Plasma HMGB1, tumor necrosis factor , (TNF-,), and interleukin-6 (IL-6) levels were measured, and HMGB1 immunohistochemistry was performed on biopsies taken before and after reperfusion. Plasma HMGB1 was undetectable before reperfusion, and levels in systemic circulation peaked after graft reperfusion. At portal declamping, HMGB1 levels were substantially higher in the caval effluent [188 (80-371) ng/mL] than in portal venous blood [0 (0-3) ng/mL, P < 0.001]. HMGB1 release from the graft continued thereafter. HMGB1 levels were not related to TNF-, or IL-6 levels. HMGB1 expression was up-regulated in biopsies taken after reperfusion (P = 0.020), with intense hepatocyte and weak neutrophil staining. HMGB1 levels in hepatic venous blood correlated with graft steatosis (r = 0.497, P = 0.03) and peak postoperative alanine aminotransferase levels (r = 0.588, P = 0.008). Our results indicate that HMGB1 originates from the graft and is a marker of hepatocellular injury in human liver transplantation. Liver Transpl 14:1517,1525, 2008. © 2008 AASLD. [source] Initial steroid bolus injection promotes vigorous CD8+ alloreactive responses toward early graft acceptance immediately after liver transplantation in humansLIVER TRANSPLANTATION, Issue 9 2007Hiroto Egawa We have found that steroid bolus withdrawal prior to graft reperfusion increased the incidence of acute cellular rejection (ACR). This study aims to clarify how initial steroid bolus (ISB) injection at reperfusion influences the kinetics of CD8+ alloreactive immune responses immediately after living donor liver transplantation (LDLT). A total of 49 hepatitis C virus (HCV)-infected recipients were classified into 3 groups according to hierarchical clustering by preoperative CD8+CD45 isoforms. The naive T cell proportion was considerably higher in Group I than in Groups II and III, whereas Group II recipients had the highest effector memory (EM) T cells and Group III the highest effector T cells. The frequency of ACR was significantly higher in recipients without ISB than in those with ISB. In particular, the ACR rates were the highest in Group II without ISB. Following ISB, the proportion of effector T cells was promptly upregulated within 6 hours after graft reperfusion, simultaneously with the upregulation of CD27,CD28, subsets, interferon-gamma (IFN-,), tumor necrosis factor-alpha and perforin expression, which significantly correlated with increasing interleukin (IL)-12 receptor beta 1 cells. These were then downregulated to below preoperative levels by tacrolimus (Tac) administered at 24 hours. These changes did not occur in the absence of ISB. In Group II without ISB, the downregulation of IL-12R,1+ cells was the greatest, consistent with the highest rates of ACR and mortality (60%). In conclusion, ISB must be done in place, especially in Group II with preexisting high EM T cells, to enable the development of early allograft acceptance. Liver Transpl 13:1262,1271, 2007, © 2007 AASLD. [source] Venous hemodynamics in living donor right lobe liver transplantationLIVER TRANSPLANTATION, Issue 9 2002Gabriel E. Gondolesi MD We evaluated the influence of portal and hepatic venous hemodynamics on the immediate and 3-month postoperative function of living donor right lobe grafts. Portal velocity was measured prospectively by ultrasound in 14 consecutive donor/recipient pairs. Velocity was converted to flow with the Moriyasu formula. Measurements were taken in donors in the operating room and in recipients at 1 hour after reperfusion and 3 months after transplant. Recipient liver function tests were measured postoperatively. Prereperfusion and postreperfusion liver biopsies were evaluated and correlated with the hemodynamic and biochemical results. There were 11 male (78.6%) and 3 female donors (mean age, 38.9 ± 9.8 years) for 10 male (71.4%) and 4 female recipients (mean age, 49.3 ± 14 years). The mean graft/recipient weight ratio was 1.22 ± 0.3. The mean right portal vein pressure was 8 ± 1.8 mm Hg in donors versus 13 ± 4.7 mm Hg in recipients (P < .05). The mean peak flow velocity (Vmax) in the portal vein in donors was 47.6 ± 12.8 cm/sec (normal, 44 cm/sec). One hour after graft reperfusion in the recipient, the mean portal Vmax was significantly higher at 94.7 ± 28.4 cm/sec (P = .004), but by 3 months follow-up, mean portal Vmax had fallen to 58.8 ± 37.8 (P = .01). Recipient portal vein Vmax highly correlated with portal flow (r = 0.7, P = .01). Increased recipient total bilirubin on postoperative day 2 correlated highly with higher recipient portal flow one hour after transplant (r = 0.6; P = .03). Portal vein velocity/flow dramatically increases after reperfusion, returning to baseline about 3 months after transplant. Evaluation of hepatic and portal venous flow is a relatively easy skill to acquire. Intraoperative ultrasound may enable the surgeon to predict graft dysfunction and possibly, may be used to implement pre-emptive therapies. [source] Early phase of reperfusion of human kidney allograft does not affect an erythrocyte anti-oxidative systemNEPHROLOGY, Issue 5 2006LESZEK DOMA SUMMARY: Background: Generation of reactive oxygen specimens is the basic mechanism leading to ischaemia/reperfusion injury of the kidney graft. Oxygen burst is a trigger for sophisticated biochemical changes leading to generation of oxygenated lipids and changes in microcirculation, which recruit recipient's neutrophils and contribute to delayed graft function. It has been shown that the free radicals generation correlates with the activity of anti-oxidative system. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH) are involved in protection against free radicals. Aim: To examine the activity of erythrocyte anti-oxidative system during reperfusion of the transplanted kidney allograft. Methods: The study included 40 renal transplant recipients. Blood was taken from the iliac vein before transplantation and from the graft's renal vein immediately, as well as 2 and 4 min after total reperfusion. The authors assessed the process of reperfusion using ThermaCAM SC500 termovision camera. Spectrophotometric methods were used to measure superoxide dismutase, glutathione peroxidase and catalase activity as well as glutathione concentrations in erythrocytes. Results: There were no statistically significant differences in the activities of superoxide dismutase, catalase and glutathione peroxidase as well as glutathione concentrations during the first 4 min after total graft reperfusion. Nevertheless, there was a positive correlation between the activity of superoxide dismutase and glutathione peroxidase. Conclusion: The results suggest that the erythrocyte anti-oxidative system is stable during the early phase after reperfusion. An association between some anti-oxidative enzymes was noted. [source] Effect of donor pneumoperitoneum on early allograft perfusion following renal transplantation in pediatric patients: An intraoperative Doppler ultrasound studyPEDIATRIC TRANSPLANTATION, Issue 5 2008S. Dave Abstract:, Decreased perfusion and trauma during laparoscopic harvesting are proposed causative factors for DGF and rejection in children following renal transplantation with laparoscopic donor nephrectomy (LDN) allograft. We performed a retrospective review of 11 children who underwent LDN transplant and 11 preceding patients who underwent ODN transplant. Intraoperative DUS findings, creatinine values and clearance, time to nadir creatinine and AR episodes were compared. There were no significant differences in the BMI, vascular anatomy, side of nephrectomy, or warm ischemia time in the two groups. Mean follow-up duration was 11.4 and 30.4 months in LDN and ODN groups. DUS showed initial turbulent flow in five of the LDN and four of the ODN group with an average RI of 0.59 and 0.66 in the ODN and LDN groups, respectively (NS). Three patients in the ODN group had an abnormal RI compared to none in the LDN group (p = 0.034). The creatinine values, creatinine clearances (at 24 h, one, four wk and last follow-up) and AR episodes were similar in both groups. Pneumoperitoneum during LDN does not appear to have an adverse impact on early graft reperfusion. [source] Early Renal Ischemia-Reperfusion Injury in Humans Is Dominated by IL-6 Release from the AllograftAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2009D. K. De Vries The pathophysiology of ischemia/reperfusion (I/R) injury is complex, and current knowledge of I/R injury in humans is incomplete. In the present study, human living-donor kidney transplantation was used as a highly reproducible model to systematically study various processes potentially involved in early I/R injury. Unique, direct measurements of arteriovenous concentration differences over the kidney revealed massive release of interleukin (IL)-6 in the first 30 minutes of graft reperfusion and a modest release of IL-8. Among the assessed markers of oxidative and nitrosative stress, only 15(S)-8- iso -PGF2, was released. When assessing cell activation, release of prothrombin factor 1 + 2 indicated thrombocyte activation, whereas there was no release of markers for endothelial activation or neutrophil activation. Common complement activation complex sC5b-9 was not released into the bloodstream, but was released into urine rapidly after reperfusion. To investigate whether IL-6 plays a modulating role in I/R injury, a mouse experiment of renal I/R injury was performed. Neutralizing anti-IL-6 antibody treatment considerably worsened kidney function. In conclusion, this study shows that renal I/R in humans is dominated by local IL-6 release. Neutralization of IL-6 in mice resulted in a significant aggravation of renal I/R injury. [source] Activity of CuZn-superoxide dismutase, catalase and glutathione peroxidase in erythrocytes in kidney allografts during reperfusion in patients with and without delayed graft functionCLINICAL TRANSPLANTATION, Issue 1 2006L Doma Abstract:, Background:, Generation of reactive oxygen species (ROS) is the main mechanism involved in the ischemic/reperfusion damage of the transplanted organ. Oxygen burst is a trigger for complex biochemical events leading to generation of oxygenated lipids and changes in microcirculation. Many markers have been researched to prove the presence of ROS in the transplanted tissue. Some of them, like superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) are considered to play a major role in graft protection against oxygen stress during reperfusion. Methods:, The aim of this study was to examine the changes of SOD1, CAT and GPx activity in erythrocytes during the first minutes after total graft reperfusion. Forty patients undergoing kidney transplantation at our center were assigned to two groups: with or without delayed graft function (DGF). Before anastomosing kidney vessels with recipient's iliac vessels, the ,0' blood sample was taken from the iliac vein. Next blood samples I, II and III were taken from the graft's renal vein. The reperfusion of the transplanted kidney was evaluated precisely with the thermovision camera. Erythrocyte SOD1, CAT and GPx activity was measured with a spectrophotometric method. Results:, We did not observe statistically significant changes in SOD1, CAT and GPx activity in erythrocytes during the early phase of reperfusion in patients with and without DGF. Conclusions:, Erythrocyte-antioxidative system in graft's vein remain stable during the early phase of reperfusion. The results of the study suggest that further studies on extracellular enzymes are required for the assessment of antioxidant system in the conditions of ischemia/reperfusion. [source] | ||||||||||