Home About us Contact
|
Home About us Contact | ||
|
|
||
Cold Preservation (cold + preservation)
Selected AbstractsAnti-thrombin Therapy During Warm Ischemia and Cold Preservation Prevents Chronic Kidney Graft Fibrosis in a DCD ModelAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2010F. Favreau Ischemia reperfusion injury (IRI) is pivotal for renal fibrosis development via peritubular capillaries injury. Coagulation represents a key mechanism involved in this process. Melagatran® (M), a thrombin inhibitor, was evaluated in an autotransplanted kidney model, using Large White pigs. To mimic deceased after cardiac death donor conditions, kidneys underwent warm ischemia (WI) for 60 min before cold preservation for 24 h in University of Wisconsin solution. Treatment with M before WI and/or in the preservation solution drastically improved survival at 3 months, reduced renal dysfunction related to a critical reduction in interstitial fibrosis, measured by Sirius Red staining. Tissue analysis revealed reduced expression of transforming growth factor-, (TGF-,) and activation level of its effectors phospho-Smad3, Smad4 and connective tissue growth factor (CTGF) after M treatment. Fibrinolysis activation was also observed, evidenced by downregulation of PAI-1 protein and gene expression. In addition, M reduced S100A4 expression and vimentin staining, which are markers for epithelial mesenchymal transition, a major pathway to chronic kidney fibrosis. Finally, expression of oxidative stress markers Nox2 and iNOS was reduced. We conclude that inhibition of thrombin is an effective therapy against IRI that reduces chronic graft fibrosis, with a significantly positive effect on survival. [source] Normothermic Ex Vivo Perfusion Prevents Lung Injury Compared to Extended Cold Preservation for TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2009M. Cypel Treatment of injured donor lungs ex vivo to accelerate organ recovery and ameliorate reperfusion injury could have a major impact in lung transplantation. We have recently demonstrated a feasible technique for prolonged (12 h) normothermic ex vivo lung perfusion (EVLP). This study was performed to examine the impact of prolonged EVLP on ischemic injury. Pig donor lungs were cold preserved in Perfadex® for 12 h and subsequently divided into two groups: cold static preservation (CSP) or EVLP at 37°C with SteenÔ solution for a further 12 h (total 24 h preservation). Lungs were then transplanted and reperfused for 4 h. EVLP preservation resulted in significantly better lung oxygenation (PaO2 531 ± 43 vs. 244 ± 49 mmHg, p < 0.01) and lower edema formation rates after transplantation. Alveolar epithelial cell tight junction integrity, evaluated by zona occludens-1 protein staining, was disrupted in the cell membranes after prolonged CSP but not after EVLP. The maintenance of integrity of barrier function during EVLP translates into significant attenuation of reperfusion injury and improved graft performance after transplantation. Integrity of functional metabolic pathways during normothermic perfusion was confirmed by effective gene transfer and GFP protein synthesis by lung alveolar cells. In conclusion, EVLP prevents ongoing injury associated with prolonged ischemia and accelerates lung recovery. [source] Cold-induced apoptosis of rat liver cells in University of Wisconsin solution: The central role of chelatable ironHEPATOLOGY, Issue 3 2002Uta Kerkweg Although University of Wisconsin (UW) solution aims at the prevention of cold-induced cell injury, it failed to protect against cold-induced apoptosis of hepatocytes and liver endothelial cells: when incubated in UW solution at 4°C for 24 hours and subsequently rewarmed at 37°C, 72% ± 8% of rat hepatocytes and 81% ± 5% of liver endothelial cells lost viability. In both cell types, the observed cell damage occurred under an apoptotic morphology; it appeared to be mediated by a rapid increase in the cellular chelatable iron pool by a factor ,2 (as determined in hepatocytes) and subsequent formation of reactive oxygen species (ROS). Consequently, this cell injury was decreased by iron chelators to 6 to 25% (hepatocytes) and 4% ± 2% (liver endothelial cells). Deferoxamine nearly completely inhibited the occurrence of apoptotic morphology in both cell types. In liver endothelial cells, cold-induced apoptosis occurring during rewarming after 24 hours of cold incubation in UW solution was far more pronounced than in cell culture medium (loss of viability: 81% ± 5% vs. 28% ± 13%), but viability could even be maintained for 2 weeks of cold incubation by use of deferoxamine. In conclusion, this pathological mechanism might be an explanation for the strong endothelial cell injury known to occur after cold preservation. With regard to the extent of this iron-mediated injury, addition of a suitable iron chelator to UW solution might markedly improve the outcome of liver preservation. [source] EFFECT OF STORAGE TEMPERATURE ON HISTAMINE FORMATION IN SARDINA PILCHARDUS AND ENGRAULIS ENCRASICOLUS AFTER CATCHJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2007PIERINA VISCIANO ABSTRACT Histamine formation in Sardina pilchardus and Engraulis encrasicolus as a function of storage temperature was studied. Fish were caught off the Adriatic Coast and were carried immediately to the laboratory. A portion of dorsal muscle from each fish was soon analyzed, while two other portions were examined after storage at two different temperatures (25 and 4C) for 24 and 72 h, respectively. The analyses were carried out by high-performance liquid chromatography (HPLC)-UV and confirmed by HPLC-diode array detector. Histamine concentrations were always higher than the European Community admissible levels in samples stored at 25C. In fish stored at 4C, histamine was detected only in E. encrasicolus. PRACTICAL APPLICATIONS Time experiments were conducted to quantify the histamine formation in scombroid species at two different temperatures. The first assay (24 h, 25C) could reproduce the modality of sale adopted by fishermen or retailers in summer on the one hand, and the maintenance at ambient temperature of semipreserved sardines or anchovies during salting and ripening on the other hand. The second experiment (72 h, 4C) was based on the domestic cold preservation of fish before the consumption, which sometimes occurs some days after purchasing. Even if ice storage is recommended, time/temperature abuse conditions often occur in the fish merchandising chain. The results of this research showed that high histamine concentrations could be found in the analyzed species not only at an abused temperature, but also at a common storage temperature of fish at home. [source] Rapamycin inhibits cholangiocyte regeneration by blocking interleukin-6,induced activation of signal transducer and activator of transcription 3 after liver transplantationLIVER TRANSPLANTATION, Issue 2 2010Li-Ping Chen Cholangiocyte proliferation is necessary for biliary recovery from cold ischemia and reperfusion injury (CIRI), but there are few studies on its intracellular mechanism. In this process, the role of rapamycin, a new immunosuppressant used in liver transplantation, is still unknown. In order to determine whether rapamycin can depress cholangiocyte regeneration by inhibiting signal transducer and activator of transcription 3 (STAT3) activation, rapamycin (0.05 mg/kg) was administered to rats for 3 days before orthotopic liver transplantation. The results indicated that cholangiocytes responded to extended cold preservation (12 hours) with severe bile duct injures, marked activation of the interleukin-6 (IL-6)/STAT3 signal pathway, and increased expression of cyclin D1 until 7 days after transplantation, and this was followed by compensatory cholangiocyte regeneration. However, rapamycin treatment inhibited STAT3 activation and resulted in decreased cholangiocyte proliferation and delayed biliary recovery after liver transplantation. On the other hand, rapamycin showed no effect on the expression of IL-6. We conclude that the IL-6/STAT3 signal pathway is involved in initiating cholangiocytes to regenerate and repair CIRI. Rapamycin represses cholangiocyte regeneration by inhibiting STAT3 activation, which might have a negative effect on the healing and recovery of bile ducts in grafts with extended cold preservation. Insights gained from this study will be helpful in designing therapy using rapamycin in clinical patients after liver transplantation. Liver Transpl, 2010. © 2010 AASLD. [source] Liver graft exposure to carbon monoxide during cold storage protects sinusoidal endothelial cells and ameliorates reperfusion injury in ratsLIVER TRANSPLANTATION, Issue 11 2009Atsushi Ikeda Hepatic ischemia/reperfusion (I/R) injury significantly influences short-term and long-term outcomes after liver transplantation (LTx). The critical step initiating the injury is known to include sinusoidal endothelial cell (SEC) alteration during the cold preservation period. As carbon monoxide (CO) has potent cytoprotective functions on vascular endothelial cells, this study examined if CO treatment of excised liver grafts during cold storage could protect SECs and ameliorate hepatic I/R injury. Rat liver grafts were preserved in University of Wisconsin (UW) solution containing 5% CO (CO-UW solution) for 18 to 24 hours and were transplanted into syngeneic Lewis rats. After 18 hours of cold preservation, SEC damage was evident with propidium iodide (PI) nuclear staining on SECs, and the frequency of PI+ SECs was significantly lower in grafts stored in CO-UW solution versus those stored in control UW solution. SEC protection with CO was associated with decreased intercellular cell adhesion molecule translocation and less matrix metalloproteinase release during cold preservation. After LTx with 18 hours of cold preservation, serum alanine aminotransferase levels and hepatic necrosis were significantly less in the CO-UW group than in the control UW group. With 24 hours of cold storage, 35% (7/20) survived with control UW solution, whereas the survival with CO-UW solution improved to 80% (8/10). These beneficial effects of CO-UW solution were associated with a significant reduction of neutrophil extravasation, down-regulation of hepatic messenger RNA for tumor necrosis factor alpha and intercellular cell adhesion molecule 1, and less hepatic extracellular signal-regulated kinase activation. Liver grafts from Kupffer cell,depleted donors or pseudogerm-free donors showed less SEC death during cold preservation, and CO-UW solution further reduced SEC death. In conclusion, CO delivery to excised liver grafts during cold preservation efficiently ameliorates SEC damage and hepatic I/R injury. Liver Transpl 15:1458,1468, 2009. © 2009 AASLD. [source] Mediators of rat ischemic hepatic preconditioning after cold preservation identified by microarray analysisLIVER TRANSPLANTATION, Issue 11 2006Ŕurea Navarro-Sabaté Hepatic ischemia-reperfusion injury associated with liver transplantation is an as yet unresolved problem in clinical practice. Preconditioning protects the liver against the deleterious effects of ischemia, although the mechanism underlying this preconditioning is still unclear. To profile gene expression patterns involved in hepatic ischemic preconditioning, we analyzed the changes in gene expression in rat livers by DNA microarray analysis. Approximately 116 genes were found to have altered gene expression after 8 hours of cold ischemia. Moreover, the expression of 218 genes was modified by classic preconditioning followed by the same ischemia process. Given the importance of the effects of ischemic preconditioning (IP) in minimizing the liver damage induced by sustained ischemia before reperfusion, this study analyzed the putative genes involved in the beneficial role of IP in liver grafts undergoing cold ischemia before its implantation in the recipient (IP+I). Great differences were found in the gene expression pattern of ischemic preconditioning + long cold ischemia (IP+I) group when compared with the long cold ischemia alone condition (I), which could explain the protective regulatory mechanisms that take place after preconditioning. Twenty-six genes that were downregulated in cold ischemia were found upregulated after preconditioning preceding a long cold ischemia period. These would be genes activated or maintained by preconditioning. Heat shock protein genes and 3-hydroxy-3-methylglutaryl-coenzyme A reductase are among the most markedly induced transcripts. Liver Transpl. 12:1615,1625, 2006. © 2006 AASLD. [source] Non-heart-beating donor porcine livers: The adverse effect of coolingLIVER TRANSPLANTATION, Issue 1 2005Srikanth Reddy Normothermic preservation has been shown to be advantageous in an experimental model of preservation of non-heart-beating donor (NHBD) livers, which have undergone significant warm ischemic injury. The logistics of clinical organ retrieval might dictate a period of cold preservation prior to warm perfusion. We have investigated the effects of a brief period of cold preservation on NHBD livers prior to normothermic preservation. Porcine livers were subjected to 60 minutes of warm ischaemia and then assigned to following groups: Group W (n = 5), normothermic preservation for 24 hours; and Group C (n = 6), cold preservation in University of Wisconsin solution for 1 hour followed by normothermic preservation for 23 hours (total preservation time, 24 hours). Synthetic function (bile production and factor V production) and cellular damage were compared on the ex vivo circuit during preservation. There was no significant difference in the synthetic function of the livers (bile production and factor V production). Markers of hepatocellular damage (alanine aminotransferase and aspartate aminotransferase release), sinusoidal endothelial cell dysfunction (hyaluronic acid), and Kupffer cell injury (,-galactosidase) were significantly higher in Group C. The histology of the livers at the end of perfusion was similar. In conclusion, a brief-period cold preservation prior to normothermic perfusion maintains the synthetic function and metabolic activity but results in significant hepatocellular damage, sinusoidal endothelial cell dysfunction, and Kupffer cell injury. Transplant studies are required to establish whether livers treated in this way are viable for transplantation. (Liver Transpl 2005;11:35,38.) [source] Biliary inorganic phosphate as a tool for assessing cold preservation-reperfusion injury: A study in the isolated perfused rat liver modelLIVER TRANSPLANTATION, Issue 2 2003Luciana L. Almada Ischemia-reperfusion injury is a major cause of early graft dysfunction after liver transplantation. The bile flow has been suggested as an index of ischemic damage, and severely impaired bile flow seems to be predictive of poor survival in experimental studies. Looking for injury markers, biliary inorganic phosphate has the potential of being a useful endogenous marker of diminished hepatobiliary function because this anion is excreted in the bile by a paracellular pathway and it can detect changes in permeability. The goal of this study was to evaluate the effects of cold preservation-reperfusion of the liver on bile flow and bile inorganic phosphate and their relationship with storage-related graft failure. The isolated and perfused rat liver was used to evaluate the injury for ischemia-reperfusion. The intrahepatic resistance, lactate dehydrogenase release, and potassium and biliary inorganic phosphate concentration were used to estimate viability and function of freshly isolated or cold-preserved livers. The intrahepatic resistance and the bile flow were consistent and significantly decreased throughout the perfusion time in relation to the increment in storage. Inorganic phosphate is more concentrated in bile from preserved livers, showing an alteration in paracellular pathway, confirmed by the biliary excretion of horseradish peroxidase. After preservation, concentration and excretion of the paracellular marker were increased during the first peak. The second peak appears earlier in preserved livers (10 minutes) with a different shape but without changes in concentration. In conclusion, inorganic phosphate in bile shows changes in paracellular permeability as occurs in livers after 48 hours of cold preservation. [source] Hepatic steatosis and its relationship to transplantationLIVER TRANSPLANTATION, Issue 5 2002Charles J. Imber FRCS Fatty infiltration of the liver is common in the brain-dead donor population and has a strong correlation with primary nonfunction after cold preservation, a condition that is catastrophic to liver transplant recipients. This literature review examines factors associated with the development, diagnosis, quantification, and clinical management of this difficult condition. [source] Metabolic changes in the liver graft monitored continuously with microdialysis during liver transplantation in a pig modelLIVER TRANSPLANTATION, Issue 5 2002Grzegorz Nowak MD Microdialysis provides the opportunity to continuously monitor metabolic changes in tissue. The aim of the study is to monitor metabolic changes in the liver graft over time during transplantation in a pig model. Fourteen littermate female pigs with a body weight of 30 to 34 kg were used for seven orthotopic liver transplantations. Intrahepatic implantation of a microdialysis catheter into the liver graft was performed in the donor. Microdialysis samples were collected at 20-minute intervals during the donor operation, cold preservation, and for 7 hours after reperfusion in the recipient. Glucose, lactate, pyruvate, and glycerol concentrations were measured. After cold perfusion, glucose, lactate, and glycerol levels increased, whereas pyruvate levels decreased rapidly. During cold storage, glucose and glycerol levels increased, whereas lactate levels remained stable and pyruvate levels were undetectable. During implantation of the liver graft, glucose, lactate, and glycerol levels showed an accelerated increase. After portal reperfusion, glucose, lactate, and glycerol levels continued to increase for another 40 to 60 minutes, after which they decreased and finally settled at normal levels. At this time, pyruvate levels increased, with a peak within 2 hours after reperfusion, and then decreased to normal levels. Calculated lactate-pyruvate ratio increased after cold perfusion and remained stable during cold storage. During rewarming, it showed an accelerated increase, but after reperfusion, it decreased rapidly. Rewarming and reperfusion are most harmful to the liver, reflected by an accelerated increase in glucose and glycerol levels and lactate-pyruvate ratio. High intrahepatic glucose levels during ischemia appear to be a liver-specific event, which may represent glycogen degradation in injured hepatocytes. [source] Role of hepatocytes and bile duct cells in preservation-reperfusion injury of liver graftsLIVER TRANSPLANTATION, Issue 5 2001Marián Kukan In liver transplantation, it is currently hypothesized that nonparenchymal cell damage and/or activation is the major cause of preservation-related graft injury. Because parenchymal cells (hepatocytes) appear morphologically well preserved even after extended cold preservation, their injury after warm reperfusion is ascribed to the consequences of nonparenchymal cell damage and/or activation. However, accumulating evidence over the past decade indicated that the current hypothesis cannot fully explain preservation-related liver graft injury. We review data obtained in animal and human liver transplantation and isolated perfused animal livers, as well as isolated cell models to highlight growing evidence of the importance of hepatocyte disturbances in the pathogenesis of normal and fatty graft injury. Particular attention is given to preservation time-dependent decreases in high-energy adenine nucleotide levels in liver cells, a circumstance that (1) sensitizes hepatocytes to various stimuli and insults, (2) correlates well with graft function after liver transplantation, and (3) may also underlie the preservation time-dependent increase in endothelial cell damage. We also review damage to bile duct cells, which is increasingly being recognized as important in the long-lasting phase of reperfusion injury. The role of hydrophobic bile salts in that context is particularly assessed. Finally, a number of avenues aimed at preserving hepatocyte and bile duct cell integrity are discussed in the context of liver transplantation therapy as a complement to reducing nonparenchymal cell damage and/or activation. [source] Interspecies differences in hepatic Ca2+ -ATPase activity and the effect of cold preservation on porcine liver Ca2+ -ATPase functionLIVER TRANSPLANTATION, Issue 2 2001Piotr K. Janicki MD The accumulation of intracellular calcium ([Ca2+]i) caused by ischemia-reperfusion during liver transplantation has been implicated as a factor leading to primary graft nonfunction. Plasma membrane (PM) and endoplasmic reticulum (ER) Ca2+ -adenosinetriphosphatases (ATPases) are the primary transporters that maintain [Ca2+]i homeostasis in the liver. We hypothesized that the porcine liver is better than the rat liver as a model for the study of human liver Ca2+ -ATPase activity. We also hypothesized that cold preservation would depress Ca2+ -ATPase activity in the porcine liver. Pig and rat livers were harvested, and human liver samples were obtained from surgical resection specimens. All were preserved with University of Wisconsin solution, and porcine livers were also preserved on ice for 2 to 18 hours. Ca2+ -ATPase activity was measured after incubation with 45Ca2+ and adenosine triphosphate in the presence of specific Ca2+ -ATPase inhibitors. Porcine PM and ER Ca2+ -ATPase activities were 0.47 ± 0.03 and 1.57 ± 0.10 nmol of Ca2+/mg of protein/min, respectively. This was not significantly different from human liver, whereas rat liver was significantly greater at 2.60 ± 0.03 and 9.2 ± 0.9 nmol of Ca2+/mg of protein/min, respectively. We conclude that the Ca2+ -ATPase activity in the pig liver is equivalent to that of human liver, and thus, the pig liver is a better model than the rat liver. Cold preservation studies showed a significant decrease in porcine hepatic PM Ca2+ -ATPase activity after 4 hours of storage and near-total inhibition after 12 hours. Porcine hepatic ER Ca2+ -ATPase activity showed a 45% decrease in activity by 12 hours and a 69% decrease by 18 hours. We conclude that cold ischemia at clinically relevant times depresses PM Ca2+ -ATPase more than ER Ca2+ -ATPase activity in pig liver homogenates. [source] Anti-thrombin Therapy During Warm Ischemia and Cold Preservation Prevents Chronic Kidney Graft Fibrosis in a DCD ModelAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2010F. Favreau Ischemia reperfusion injury (IRI) is pivotal for renal fibrosis development via peritubular capillaries injury. Coagulation represents a key mechanism involved in this process. Melagatran® (M), a thrombin inhibitor, was evaluated in an autotransplanted kidney model, using Large White pigs. To mimic deceased after cardiac death donor conditions, kidneys underwent warm ischemia (WI) for 60 min before cold preservation for 24 h in University of Wisconsin solution. Treatment with M before WI and/or in the preservation solution drastically improved survival at 3 months, reduced renal dysfunction related to a critical reduction in interstitial fibrosis, measured by Sirius Red staining. Tissue analysis revealed reduced expression of transforming growth factor-, (TGF-,) and activation level of its effectors phospho-Smad3, Smad4 and connective tissue growth factor (CTGF) after M treatment. Fibrinolysis activation was also observed, evidenced by downregulation of PAI-1 protein and gene expression. In addition, M reduced S100A4 expression and vimentin staining, which are markers for epithelial mesenchymal transition, a major pathway to chronic kidney fibrosis. Finally, expression of oxidative stress markers Nox2 and iNOS was reduced. We conclude that inhibition of thrombin is an effective therapy against IRI that reduces chronic graft fibrosis, with a significantly positive effect on survival. [source] High Levels of Donor CCL2/MCP-1 Predict Graft-Related Complications and Poor Graft Survival After Kidney-Pancreas TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2008A. C. Ogliari In this study we analyzed the role of CCL2, a member of the chemokine family, in early graft damage. Using simultaneous kidney-pancreas transplantation (SPK) as a model, we showed that brain death significantly increases circulating CCL2 levels in humans. We found that in such situations, high donor CCL2 levels (measured before organ recovery and at the onset of cold preservation) correlate with increased postreperfusion release of CCL2 by both the graft and recipient throughout the week following transplantation (n = 28). In a retrospective study of 77 SPK recipients, we found a significant negative association between high donor levels of CCL2 and graft survival. Decreased survival in these patients is related to early posttransplant complications, including a higher incidence of pancreas thrombosis and delayed kidney function. Taken together our data indicate that high CCL2 levels in the donor serum predict both an increase in graft/recipient CCL2 production and poor graft survival. This suggests that the severity of the inflammatory response induced by brain death influences the posttransplant inflammatory response, independent of subsequent ischemia and reperfusion. [source] Experimental study of a type 3 phosphodiesterase inhibitor on liver graft functionBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 1 2001T. Ikegami Background: The number of liver transplant recipients is increasing but donor organ shortages have become more severe. The effect of milrinone, a type 3 phosphodiesterase inhibitor (PDEI), on non-heart-beating donor grafts was evaluated using an orthotopic liver transplantation model in rats. Methods: Type 3 PDEI or normal saline (control group) was given intravenously to the donor animals for 60 min continuously (50 µg kg,1 min,1 ) before 60 min of warm ischaemia followed by cold preservation and subsequent transplantation. Survival, serum chemistry, bile output, histopathological findings and tissue cyclic 3,,5,-adenosine monophosphate (cAMP) concentrations were then compared. Results: Five of seven animals in the PDEI group were alive at 7 days, compared with only one of seven rats in the control group (P < 0·01). Serum levels of alanine aminotransferase 2 and 6 h after reperfusion, and hyaluronic acid levels 6 h after reperfusion, were significantly lower in the PDEI group than in the control group. Bile output from the transplanted graft was significantly greater in the PDEI group than in controls 2 h after reperfusion (P < 0·01). The mean necrotic area 6 h after reperfusion was also reduced in the PDEI-treated grafts (P < 0·01). cAMP levels in liver tissue at the end of both warm and cold ischaemia, and 2 and 6 h after reperfusion, were significantly higher in the PDEI group compared with those in the control group. Conclusion: Type 3 PDEI attenuated the graft injury caused by warm and cold ischaemia and subsequent reperfusion injury via an increase in intracellular cAMP levels. This treatment may be a novel pharmacological intervention for safe and efficient usage of liver grafts from non-heart-beating donors. © 2001 British Journal of Surgery Society Ltd [source] | ||||||||||