Protective role of nitric oxide induced by ischemic preconditioning on cold ischemic-reperfusion injury of rat liver graft

Aims

To investigate the protective role of nitric oxide (NO) induced by ischemic preconditioning (IP) on cold ischemic-reperfusion (IR) injury of rat liver grafts.

Methods

One hundred twenty-eight male Sprague Dawley rats used for orthotopic liver transplantation were randomly divided into four groups (n = 32): administering heparin before ischemic reperfusion (control group); IP with 10-minute ischemia and 10-minute reperfusion before IR (IP group); adenosine before IR (Ade group); and L-NAME (NG-nitro-L-arginine methyl ester) + IP before IR (NAME group). Half of each group were used to investigate 1-week recipient survival rate, and another to obtain blood and hepatic tissue samples after 2-hour reperfusion.

Results

One-week survival bile production, serum NO, and antioxidase activity were higher but serum alanine aminotransferase, tumor necrosis factor-α, and superoxide levels in hepatic tissue were lower in the IP group and Ade group versus the control group or NAME group. Liver sinusoidal endothelial cells in the IP and Ade groups showed less injury than the other groups.

Conclusion

NO induced by IP can improve 1-week survival and rat liver function as well as protect liver sinusoidal endothelial cells.     

Hepatic Changes During Various Periods of Reperfusion After Induction of Renal Ischemia in Rats

Background

Recent studies have suggested that ischemic damage to the kidneys causes liver tissue alterations. Thus, the morbidity and mortality in patients with acute renal failure (ARF) may be related to liver complications as well as to renal injury. The aim of the present study was to assess the hepatic changes during various periods of reperfusion after induction of renal ischemia.

Methods

Forty male rats were subjected to either a sham operation or to a 45-minute ischemia followed by 1, 3, 6, or 24 hours of reperfusion. Arterial pressure was continuously monitored. Blood samples were drawn to measure serum creatinine and blood urea nitrogen (BUN).

Results

We evaluated hepatic concentrations of interleukin (IL)-10 and tumor necrosis factor (TNF)-α. Ischemia reperfusion (IR) caused significant reductions in renal function as demonstrated by increased values of serum creatinine and BUN. These rats also showed significant increases in hepatic TNF-α and IL-10 concentrations. The most significant changes among inflammatory factors in the liver were observed at 3 hours of reperfusion: TNF-α, 616 ± 41 vs 215 ± 16, and IL-10, 926 ± 73 vs 125 ± 34, pg/100 mg tissue (P ≤ .05). Twenty-four-hour reperfusion reduced the extent of liver injury.

Discussion

Renal IR affects liver inflammatory status, possibly due to increased renal production or impaired clearance of mediators of tissue injury, namely proinflammatory cytokines. The reduction in liver injury at 24 hours of reperfusion compared with the other groups, suggested activation of late-protective mechanisms. These observations may be important for clinical interventions to reduce the morbidity and mortality of ARF.     

Activation of Complement in the Discordant Heart Xenotransplantation of Pig-to-Monkey Model and the Impact of Intrathymic Inoculation of Xenogeneic Antigen Combined With Whole-Body γ-Radiation

Objective

This study investigated changes in complement in discordant heart xenotransplantation using a pig-to-monkey model as well as the impact of intrathymic inoculation (IT) with xenogeneic antigen combined with whole-body γ-radiation (WBI).

Methods

In this experiment, pigs and monkeys selected as donors and recipients, respectively, were randomly divided into three groups: a blank group (group A), a whole-body irradiation group (group B) and an irradiation plus intrathymic injection group (group C). In every group, monkeys underwent heterotopic heart xenotransplantation.

Results

The results showed that the survival of donor hearts in group C was significantly longer than that of group A (P < .01). In mixed lymphocyte reactions, there was a significant reduction of the stimulation index in group C compared with group A. After xenotransplantation, the level of xenoreactive antibody in group C rose slower than that in group A or group B (P < .01). After rejection, the levels of CD46 and C3 declined greatly.

Conclusions

These results suggested that pretreatment with IT and WBI induced T-cell immunosuppression, restraining elicited xenoreactive antibody production of both immunoglobulin M and immunoglobulin G classes. However, it did not hinder complement activation via the classical pathway during hyperacute rejection and consequent xenograft rejection.     

Intracellular oxygenation and cytochrome oxidase C activity in ischemic preconditioning of steatotic rabbit liver

Background

Mild to moderate steatotic livers are used as marginal donors in liver transplantation. Very little is known about the mechanisms of ischemia reperfusion (IR) injury (IRI) in fatty liver. This study aimed to establish whether cytochrome oxidase C (COX) activity is compromised by IRI in fatty liver and whether ischemic preconditioning (IPC) can protect COX activity.

Methods

New Zealand rabbits were fed on a high-cholesterol diet for 8 weeks to induce moderate hepatic steatosis. Three groups were tested. The IR group underwent 60 minutes of ischemia, followed by 7 hours of reperfusion. The IPC group (IPC + IR) underwent 5 minutes of ischemia, followed by 10 minutes of reperfusion and then 60 minutes of ischemia and 7 hours of reperfusion. The control group (sham) underwent the same surgical procedure, but ischemia was not induced. Deoxyhemoglobin, oxyhemoglobin, and change in the redox state of COX was continuously monitored in vivo by near-infrared spectroscopy. COX and citrate synthase (CS) activity assays were carried out on liver biopsy specimens in vitro. Bile was collected continuously during the procedure and analyzed using proton nuclear magnetic resonance spectroscopy.

Results

The IR group had decreased COX activity and tissue oxygenation represented by deoxyhemoglobin, oxyhemoglobin, COX, and elevated redox ratios of lactate/pyruvate and β-hydroxybutarate/acetoacetate in vivo and a decrease in COX and CS activity in vitro. The IPC + IR group showed higher levels of all measured parameters in vivo and showed a smaller decrease in COX and CS activity in vitro.

Conclusion

This study shows that IRI affects COX activity in fatty livers. This is attenuated by IPC.     

Protective effect of erythropoietin pretreatment in testicular ischemia-reperfusion injury in rats

Background/Purpose

This study was designed to investigate the effects of recombinant erythropoietin (EPO), a hormone widely used for treatment of uremic anemia, in rats subjected to testicular ischemia and reperfusion (I/R).

Methods

Thirty-five male rats were divided into the following: control, sham operated, ischemia (I), I/R, and I/R + EPO groups. In the I group, 2 hours of left unilateral testicular torsion were performed, and in the I/R and I/R + EPO groups, an additional 2 hours of testicular detorsions were performed. The I/R + EPO group was pretreated intraperitoneally with EPO (500 IU/kg) before reperfusion. Testicular tissue samples were examined for biochemical and histopathologic parameters. Apoptotic cells in all testes were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling technique and caspase 3 immunohistochemistry.

Results

At histopathologic examination, ischemic changes in primary spermatocytes were noted in all torted testes. Cellular damage and apoptosis were more severe in ischemic groups than the EPO-pretreated group. There were statistically significant differences in tissue biochemical parameters in the I and I/R groups compared with the I/R + EPO group.

Conclusions

The results of the present study suggest that EPO exerts protective effects against I/R injury via the modulation of free radical scavenger's activities, which decreases lipid peroxidation levels and attenuation of apoptosis.     

Prolonged Cardiac Allograft Survival in Mouse Model After Complement Depletion with Yunnan Cobra Venom Factor

Background

Activation of the complement system is the leading mechanism that causes antibody-mediated acute rejection and hyperacute rejection after xenotransplantation. The major cause of acute rejection in allogeneic transplantation is the T cell–mediated specific immune response. We studied the effects of complement on acute rejection after cardiac allotransplantation using complement depletion with cobra venom factor (CVF) in the mouse.

Materials and Methods

The Balb/c-C57 mouse model of heterotopic cardiac allograft was used. The mice were divided into 2 groups, a control group and a CVF-treated group. After intravenous injection of CVF, the experimental group was observed for allograft survival time. Twelve mice from the control and experimental groups were sacrificed on days 3, 5, and 7 after the operation. The pathologic grade of acute rejection, deposition of C3 in tissue, extent of infiltration by CD4+ and CD8+ T cells, and expression of MHC-II, B7-1, and B7-2 were compared between the 2 groups.

Results

In the CVF-treated group, mean (SD) survival of the cardiac allograft was 26.2 (1.7) days, and in the control group was 8.4 (0.4) days (P < .01). Pathologic examination and immunohistochemistry demonstrated that the grade of acute rejection, deposition of C3 in tissue, extent of infiltration of CD4+ and CD8+ T cells, and expression of MHC-II, B7-1, and B7-2 were significantly decreased in the CVF-treated group.

Conclusion

Depletion of complement in the serum with CVF inhibits acute cardiac allograft rejection in the mouse.     

Greater Hemodynamic Instability With Histidine-Tryptophan-Ketoglutarate Solution Than University of Wisconsin Solution During the Reperfusion Period in Living Donor Liver Transplantation

Objective

University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solutions are the 2 most commonly used liver preservation solutions. The aim of this study was to compare cardiovascular stability, acid-base status, and potassium concentrations between patients who received grafts preserved in either UW or HTK solution in orthotopic liver transplantation (OLT).

Patients and Methods

In this retrospective study, 87 patients who underwent living donor OLT were divided into 2 groups: UW (n = 28) and HTK (n = 59). Group HTK was subdivided into group NF-HTK (n = 31; nonflushed before reperfusion) and group F-HTK (n = 28; flushed before reperfusion). We determined mean arterial pressure (MAP) and heart rate every minute for 5 minutes after reperfusion and the maximum change in these values and incidence of postreperfusion syndrome (PRS). Body temperature, cardiovascular and acid-base parameters, as well as potassium concentrations were compared at 5 minutes before and 5 and 30 minutes after reperfusion.

Results

The maximum decreases in MAP within 5 minutes after reperfusion were significantly greater in both the NF-HTK and the F-HTK groups. The rate of PRS was significantly greater in the NF-HTK compared with the UW group. Flushing with HTK solution decreased the rate of PRS; there was no significant difference between the F-HTK and UW groups. All serial changes in body temperature, cardiovascular and acid-base parameters, as well as potassium concentrations were similar among the 3 groups.

Conclusions

The incidence of PRS was greater using HTK compared with UW solution during the reperfusion period. Therefore, careful hemodynamic management is advised when using HTK solution.     

Biological Changes After Liver Transplantation According to the Presence or Not of Graft Steatosis

Aim

To assess the consequences of graft steatosis on postoperative liver function as compared with normal liver grafts.

Patients and methods

From January 2005 to December 2007, liver transplant patients were prospectively included, excluding those who experienced arterial or biliary complications or presented acute rejection. All patients had a surgical biopsy after reperfusion. Patients were compared according to the rate of macrovacuolar steatosis: namely above or below 20%.

Results

Fifty-three patients were included: 10 in the steatosis group and 43 in the control group. No significant difference was observed in terms of morbidity, mortality, and primary non- or poor function. Nevertheless, biological changes after the procedure were significantly different during the first postoperative week. Prothrombin time, serum bilirubin, and transaminases were significantly increased among the steatosis group compared with the control group (P < .05).

Conclusion

This case-controlled study including a small number of patients, described postoperative biological changes among liver transplantations with steatosis in the graft.     

Assessment of In Vitro Heparin Complement Regulation Capacity During Real-Time Cell Analyzer Antibody-Mediated Cytolysis Assay: Compatibility Studies for Pig-to-Baboon Xenotransplantation

Objective

To assess the effect of sodium heparin concentrations on antibody- and complement-mediated cytolysis by means of a real-time cell analyzer system (RTCA) investigating the complement regulation ability of heparin to reduce or prevent hyperacute in an in vitro model of pig-to-baboon xenotransplantation.

Materials and methods

Fibroblasts isolated from the skin of two transgenic pigs were cultured in microelectronic 96-well plates for 9 hours. Then, we added 20 μL of normal sera from two healthy adult olive baboons (Papio anubis) or two volunteer healthy humans. Simultaneous cultures had added heparin at 3.5, 5, 7.5, 15, and 30 IU. Moreover, rabbit complement was added for the exogenous complement group (ExC) versus the other group only with the complement present in the sera as an endogenous complement group (EnC). Cellular cultures were monitored over 150 hours after challenge. With cellular index (CI) data recorded by the xCELLigence software system, we calculate area under the curve versus concentration (AUC) and minimum CI (CImin) versus concentration.

Results

All cultures showed decreased CI after challenge with human or baboon sera. There was a high correlation for AUC (r² > 0.90) and CImin versus concentration (r² > 0.970) during the first 40 hours postchallenge among the EnC group, regardless of human or baboon sera. However, there was no correlation for AUC and CImin for the ExC group. There was a reduction of CImin related to increased heparin concentrations.

Conclusions

The addition of heparin did not reduce antibody- and complement-mediated cytolysis assessed in vitro by RTCA in pig-to-baboon compatibility assays.     

Curcumin Nutrition for the Prevention of Mesenteric Ischemia-Reperfusion Injury: An Experimental Rodent Model

Background

Curcumin is an anti-oxidant molecule known to be a potent inhibitor of nuclear factor-κB (NF-κB). It has been shown to attenuate ischemia/reperfusion (I/R) injury in several organ systems. In this study, we sought to investigate the effects of curcumin on the prevention of superior mesenteric artery I/R injury in rats.

Methods

Wistar albino rats were randomly allocated to 3 groups: group I, sham operated (n = 10); group II, I/R injury only (n = 10); group III, curcumin-treated I/R cohort (n = 10). Group I animals underwent laparotomy without I/R injury. After group II animals underwent laparotomy, 60 minutes of superior mesenteric artery ligation were followed by 3 hours of reperfusion. In the curcumin group, 15 days before I/R, curcumin (40 mg/kg) was administered by gastric gavage. All animals were sacrificed at the end of reperfusion. Intestinal tissue samples were obtained to investigate intestinal mucosal injury; in addition we estimated levels of myeloperoxidase (MPO) activity, malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH), interleukin (IL)-6, and tumor necrosis factor (TNF)-α.

Results

There were statistically significant decreases in GSH levels, along with an increase in intestinal mucosal injury scores, MPO activity, MDA levels, NO, IL-6, and TNF-α in group I when compared with groups II and III (P = .01). Curcumin treatment in group III produced a significant increase in GSH levels, as well as a decrease in intestinal mucosal injury scores, MPO activity, MDA, and NO levels when compared with group II (P < .05).

Conclusion

This study showed that curcumin treatment significantly attenuated reperfusion injury in a superior mesenteric artery I/R model in rats.     

Propofol attenuates ischemic reperfusion-induced formation of lipid peroxides in liver transplant recipients

Objective

Ischemic reperfusion (IR) injury is known to have an important influence on the success of transplant surgery and the occurrence of complications. Malondialdehyde (MDA) is an intermediate metabolite of lipid peroxidation resulting from IR-induced reactive oxygen species. This study was designed to investigate the protective effects of propofol on IR injury in liver transplant recipients.

Methods

We analyzed 19 recipients prospectively by measuring the blood levels of MDA at nine predefined intervals; before induction of anesthesia (baseline, T0), 1 hour after surgical incision (T1), 1 minute before reperfusion (T2), 30 seconds after reperfusion (T3), as well as 1, 3, 5, 30, and 60 minutes thereafter (T4-8). These patients were randomly allocated to two groups. The propofol group received an infusion (2 mg/kg per hr) after an induction bolus (2 mg/kg). The control group was prescribed midazolam (0.2 mg/kg) for induction without intravenous anesthetic infusion for maintenance.

Results

The highest MDA level occured at T6 in the controls and T7 in the propofol group. Compared with the blood levels at baseline, the MDA levels increased significantly at T2-T8 among controls versus T2, T3, T4, and T7 in the propofol group. Compared to the control group, propofol significantly lowered MDA values at T5-T8.

Conclusion

There were significantly higher MDA levels among the control versus the propofol group at 3, 5, 30, and 60 minutes after reperfusion in liver transplant recipients.     

Cardioprotection of 17,18-epoxyeicostetraenoic acid in ischemia/reperfusion is mediated by cyclooxygenase-2: a study in a rat model

Background/Purpose

Arachidonic acid and related cardioprotective eicosanoids are released in myocardial ischemia/reperfusion injury. The present study analyzes the effects of the eicosapentaenoic acid derived 17,18-epoxyeicostetraenoic acid on isolated cardiomyocytes and investigates whether 17,18-epoxyeicostetraenoic acid serves as a potential factor in the cardio-depressant postischemic effluent.

Basic Procedures

After 10 minutes of global ex vivo stop-flow ischemia, adult rat hearts were reperfused and coronary postischemic effluent was collected over a period of 30 seconds. Nonischemic effluent was collected prior to ischemia. The effects of 17,18-epoxyeicostetraenoic acid on calcium (Ca²⁺) metabolism and contraction frequency of isolated neonatal rat cardiomyocytes were tested and compared with the effects of prior collected postischemic and nonischemic effluents. Isolated neonatal cardiomyocytes were preincubated with selective (NS-398, SC-560) and nonselective cyclooxygenase inhibitors (indomethacin) to determine whether cardio-depressive effects are mediated by cyclooxygenase.

Findings

In contrast to the nonischemic effluent, both 17,18-epoxyeicostetraenoic acid and the postischemic effluent induced a comparable decrease of the Ca²⁺ transient and the contraction frequency (P < .05 vs control). The cardio-depressive effects of 17,18-epoxyeicostetraenoic acid and the postischemic effluent were significantly attenuated after preincubation with the unselective cyclooxygenase inhibitor indomethacin and the selective cyclooxygenase-2 inhibitor NS-398 (P < .05 vs control). Selective cyclooxygenase-1 inhibition with SC-560 did not influence the effect of 17,18-epoxyeicostetraenoic acid and the postischemic effluent.

Conclusions

Our data show that the cardio-depressive effects of 17,18-epoxyeicostetraenoic acid are comparable with the postischemic effluent and are mediated by cyclooxygenase-2. Our results suggest a potential cardioprotective role of the eicosanoid 17,18-epoxyeicostetraenoic acid in heart ischemia/reperfusion injury.     

Effect of systemic corticosteroids on elective left-sided colorectal resection with colorectal anastomosis

Background

The impact of systemic steroid therapy on surgical outcome after elective left-sided colorectal resection with rectal anastomosis is not well known.

Methods

We compared 606 consecutive patients including 53 patients who were on steroids and undergoing surgery between 1995 and 2005.

Results

Postoperative mortality and anastomotic leakage rates were equivalent. The postoperative complications rate, especially infections, was higher in steroid-treated patients than in non-steroid-treated patients: 38% (20 of 53 patients) versus 25% (139 of 553 patients), respectively (P = .046). In the steroid group, univariate analysis revealed 3 significant risk factors for postoperative complications: blood transfusion, preoperative anticoagulation, and chronic respiratory failure. In a multivariate analysis, blood transfusion and chronic respiratory failure remained independent factors for postoperative complications.

Conclusion

Patients on steroids have a higher incidence of postoperative complications after elective left-sided colorectal resection with rectal anastomosis.     

Hepatic stellate cell activation and hepatic fibrosis induced by ischemia/reperfusion injury

Objective

Warm ischemia causes severe allograft damage in liver transplantation. However, the long-term effects of ischemia/reperfusion injury (IRI) on fibrosis have not been fully elucidated. In this study, we used a partial warm hepatic ischemia mouse model to monitor fibrosis in the ischemic liver.

Materials and Methods

Male BALB/c mice were divided into ischemic and sham groups (n = 30/group). Via a midline laparotomy, an atraumatic clip was used to interrupt the arterial and the portal venous blood supply to the left liver lobe. After 90 minutes of partial hepatic ischemia, the clip was removed initiating hepatic reperfusion. Samples from normal, sham, and ischemic liver tissues were collected at intervals of 1, 5, 10, 15, 20, or 30 days after operation (n = 5 for each time point) for hematoxylin-eosin (H&E), Mallory's trichrome, and alpha-smooth muscle actin (α-SMA) immunohistochemical stains for fibrosis and activation of hepatic stellate cell (HSCs).

Results

IRI caused significant HSC activation in the ischemic liver tissues. Mallory's trichrome stain demonstrated that IRI caused hepatic parenchymal fibrosis near portal tracts and central veins. With prolonged reperfusion time hepatic parenchymal fibrosis was aggravated, showing the same pattern of HSC activation. IRI also caused increased portal tract fibrosis in ischemic liver tissues, especially around biliary tracts.

Conclusions

Hepatic IRI caused HSC activation, increasing hepatic parenchymal and portal tract fibrosis in ischemic liver tissues.     

Effect of university of wisconsin and histidine-tryptophan-ketoglutarate preservation solutions on blood potassium levels of patients undergoing living-donor liver transplantation

Background

The potassium content of University of Wisconsin solution (UW) is 125 mEq/L and that of histidine-tryptophan-ketoglutarate solution (HTK) only 9 mEq/L. The aim of the present study was to analyze their effects to change potassium levels on reperfusion among patients undergoing living-donor liver transplantation.

Methods

Anesthesia records of adult living-donor liver transplant patients were reviewed retrospectively. Patients received liver graft preserved in UW were grouped in group I (GI) and HTK in group II (GII). The potassium levels in the anheptic phase were compared with those 5 minutes after reperfusion using paired Student t tests. P values of <.05 were regarded to be significant.

Results

Eighty-five GI patients showed the potassium significantly decreased from 3.76 ± 0.70 to 3.60 ± 0.74, whereas the change among 355 GII patients was almost unremarkable: 4.00 ± 0.57 to 3.96 ± 0.06 mEq/L.

Conclusions

Although UW contains a higher potassium content, it seems to have no negative impact on changes in serum potassium levels; in contrast it decreased the potassium level significantly at 5 minutes after reperfusion. Both preservation solutions maintain the patients' potassium levels within the normal range.     

Sympathetic Nerves Do Not Affect Experimental Ischemia-Reperfusion Injury of Rat Liver

Background

We investigated whether sympathetic, noradrenergic nerves participate in experimental acute ischemia-reperfusion injury of the rat liver.

Methods

Female Wistar rats (200-250 g body weight) were anesthetized with pentobarbital. After tracheotomy, we cannulated a carotid artery and jugular vein. The rats were divided in 2 groups (n = 8 per group). The control group received NaCl IV and the test group received the sympatholytic agent, guanethidine (3 mg/kg, IV). After 30 minutes of drug equilibration, laparotomy was performed to arrange the liver for temporary occlusion (by a ligature) of its vascular supply, corresponding with 70% reduction in hepatic blood flow. The rats were then allowed 60 minutes of equilibration. Thereafter, regional ischemia was induced for 30 minutes. The animals were then monitored for 2 hours of reperfusion. Blood samples for alanine aminotransferase (ALT) estimation (as a measure of injury to the parenchyma) were drawn immediately before ischemia, as well as 60 and 120 minutes after reperfusion. Readings of mean arterial pressure were taken during these times.

Results

After 2 hours of reperfusion, there were no significant differences between the groups with regard to ALT or mean arterial pressure.

Conclusion

Sympathetic, noradrenergic nerves did not affect experimental ischemia-reperfusion injury of rat liver in the current model.     

Protective role of Shenfu on ischemia-reperfusion injury of rat liver grafts

Aims

We sought to investigate the protective role of Shenfu (SF),a traditional Chinese formulation comprising Radix Ginseng and Radix Aconitum Carmichaeli on ischemia-reperfusion injury in rat liver grafts.

Methods

Ninety-six male Sprague Dawley rats were used as donors (n = 48) and recipients (n = 48) of orthotopic liver transplantation. They were randomly divided into a control group with donor livers injected with saline through the portal vein immediately after recovery versus the SF group, with livers injected with SF. Each group was further divided into 3 subgroups equally to obtain bood and hepatic tissues samples at 2, 4, and 6 hours reperfusion.

Results

At each phase, the SF group, showed significantly higher bile production (P < .05) with lower serum levels of alanine aminotransferase and tumor necrosis factor-α, and nuclear factor-κB expression in the hepatic tissues. (P < .05). SF group hepatic tissues showed less injury compared with controls.

Conclusion

SF injection seemed to protect hepatocytes from injury during the early reperfusion phase and to improve subsequent rat liver graft function.     

Congenital biliary atresia: liver injury begins at birth

Background

The timing of onset of liver injury in biliary atresia (BA) is not known, although in approximately 10% of cases, biliary pathologic condition associated with the biliary atresia splenic malformation syndrome must begin well before birth.

Methods

The study involved retrospective case-note review for infants with definite BA who underwent laparotomy within first week of life.

Results

Three infants were identified who had occlusive BA evident on the first day of life. In all cases, their liver was grossly normal, and histologic changes were trivial.

Conclusion

This suggests that the detrimental cholestatic liver injury, later characteristic of BA, only begins from the time of birth despite a prenatal occlusive biliary pathology. It may be that tissue injury only occurs with the onset of the perinatal bile surge initiating periductal bile leakage and the triggering of an inflammatory and ultimately fibrotic response.     

Correlation of cell necrosis and tissue calcification with ischemia/reperfusion injury after liver transplantation

Background

The cellular events following liver ischemia/reperfusion (I/R) during transplantation are largely unknown. The spectrum of I/R damage to the liver can be clinically revealed by the development of primary graft dysfunction or nonfunction. Because viral-induced liver necrosis has been associated with the development of calcifications in an animal model, we investigated the spectrum of I/R changes identified at an ultrastructural level among livers after liver transplant (LT).

Materials and methods

Random liver biopsies from five recipients with different degrees of liver dysfunction (LD) were processed for light (LM) and electron (EM) microscopic examination. The degree of calcification was estimated as mild-moderate or severe. The degree of cell vacuolization, used as a surrogate marker of cell necrosis, was reported as mild-moderate or severe.

Results

Two patients with severe LD had obvious calcifications by LM and EM examinations. Both showed significant vacuole formation, suggesting a severe degree of cell necrosis, and both succumbed to the sequelae of their LD. One patient showed evidence of mild calcifications at EM (but not LM) examination, with mild vacuole formation. The remaining two patients displayed no microcalcifications. Both presented only mild vacuole formation. Both patients recovered from LD and are currently alive.

Conclusion

In this preliminary report, we conclude that the clinically observed degree of LD after orthotopic liver transplant (OLT)correlates well with ultrastructural modifications. These include calcification and vacuole formation. We believe that both findings can be used as surrogate markers of a clinically significant hepatic I/R injury.