Neutrophil and macrophage activation and anaphylatoxin formation in orthotopic liver transplantation without the use of veno-venous bypass

Background. Activation of neutrophils and activation of complement may be an aetiologic factor behind circulatory insufficiency in association with reperfusion of the grafted liver.
Methods. Neutrophil and macrophage activation (determined as PMN elastase and neopterin release) and complement activation were evaluated in 15 consecutive patients undergoing orthotopic liver transplantation without the use of veno-venous bypass.
Results. The PMN elastase concentrations were increased at the end ot the anhepatic phase, 2, 5 and 30 min after start of reperfusion and 6 and 24 h postoperatively. There were significantly higher PMN elastase concentrations in patients with circulatory instability (postreperfusion syndrome) compared with those without postreperfusion syndrome. The neopterin concentration was increased 2 min after the start of reperfusion and remained elevated until 6 h postoperatively. The plasma complement C3a concentrations were increased at the end of the anhepatic phase and 2, 5 and 30 min after the start of reperfusion. The plasma C3a levels were higher in patients with postreperfusion syndrome compared to those without.
Conclusions. Activation of neutrophils and macrophages and of the complement cascade with the formation of biologically active substances may be one explanation for the circulatory instability often seen in patients undergoing orthotopic liver transplantation.     

Portal vein pressure and graft oxygen consumption monitoring during liver transplantation

Abnormal splanchnic circulation (ASC) is often detected too late, when hepatic circulation is already irreversibly compromised. If we could detect surgical or metabolic problems early after graft reperfusion, we might be able to correct them immediately before the damage becomes irreversible. The aim of this study was to determine if ASC can be predicted early after liver transplantation (LT) using portal vein pressure measurements and graft oxygen consumption monitoring. PATIENTS AND METHODS: Twenty-patients (13 men, 7 women of mean age 46 years) undergoing LT with the piggyback technique for hepatitis C virus (HCV)/hepatitis B virus (HBV)-related cirrhosis were retrospectively divided in two groups. Group A (16 patients), in which LT was successful, and group B (4 patients) in which LT was unsuccessful because of primary nonfunction (2 patients), infrahepatic portal vein thrombosis (1 patient), or hepatic vein kinking (1 patient). We then compared the portal blood pressure values and the prehepatic and posthepatic oxygen content difference (p-pDO(2)) before portal clamping; at the end of anhepatic phase; 5, 15, and 25 minutes after portal vein (PV) reperfusion; and 5, 20, 40, and 100 minutes after hepatic artery anastomosis. RESULTS: Early after graft reperfusion; portal pressure decreased to levels lower than that at baseline in group A, but remained high until the end of surgery in group B. At the end of surgery, p-pDO(2) increased more among group B than group A. CONCLUSION: ASC, specifically an increased PV resistance, can be predicted early after LT by portal vein pressure measurements and graft oxygen consumption monitoring.     

Glucose metabolism during liver transplantation in dogs

Arterial and hepatic venous blood levels of glucose were studied in 12 dogs during orthotopic liver transplantation performed under ketamine anesthesia without exogenous glucose administration. During the early part of surgery, arterial blood glucose levels were stable: 161 +/- 12 mg/dl (mean +/- SEM) after laparotomy and 183 +/- 16 mg/dl 5 min before the anhepatic stage. During the anhepatic stage, arterial blood glucose levels decreased progressively to 135 +/- 9 and 88 +/- 8 mg/dl, 5 min in the anhepatic stage and 5 min before reperfusion of the graft liver, respectively (P less than 0.05). Reperfusion of the graft liver resulted in an increase in arterial glucose levels to 206 +/- 17 and 240 +/- 24 mg/dl, 5 and 30 min after reperfusion, respectively (P less than 0.05). Hepatic venous blood glucose levels increased after reperfusion (405 +/- 37 and 346 +/- 41 mg/dl, 5 and 30 min after reperfusion, respectively) and were significantly higher than in arterial blood (P less than 0.05). Arterial plasma insulin, measured in five animals, did not change significantly during the procedure, whereas plasma glucagon levels, stable during the preanhepatic and anhepatic stages, increased steadily after reperfusion of the graft liver, from 66.1 +/- 14.2 to 108.4 +/- 38.1 pg/ml (P less than 0.05). This study shows that in dogs with ketamine anesthesia mild hypoglycemia occurs during the anhepatic stage of liver transplantation without exogenous glucose administration followed by hyperglycemia on reperfusion of the graft liver, possibly secondary to the release of glucose from the donor liver.     

NFkappaB expression during cold ischemia correlates with postreperfusion graft function

In liver transplantation, activation of NFkappaB occurs upon reperfusion, yet few data exist regarding NFkappaB activation during cold ischemia. We hypothesized that activation of NFkappaB may initially occur during cold ischemia, prior to reperfusion, and serve as an important determinant of postreperfusion function. To test this hypothesis, serial biopsies during porcine liver harvest were obtained immediately upon laparotomy, upon completion of dissection, after 45 and 120 min of cold ischemia, and 60 and 180 min after reperfusion. Nuclear extracts were isolated for Western blot analysis of NFkappaB. Hepatic function was assessed through bile output and sorbitol dehydrogenase (SDH) activity. NFkappaB expression was maximal at 45 min of cold ischemia and decreased by 120 min. The expression at 120 min of cold ischemia correlated with markers of postreperfusion function, namely bile flow and SDH activity. During reperfusion a second distinct peak occurred at 180 min. Increased expression of NFkappaB at 180 min of reperfusion correlated directly with prior expression at 120 min during cold ischemia and with increased SDH activity. These data indicate that nuclear expression of NFkappaB demonstrate two distinct peaks of activity, one during cold ischemia and one after reperfusion. Enhanced expression of NFkappaB during cold ischemia not only correlates directly with NFkappaB expression during reperfusion, but also correlates inversely with postreperfusion graft function.     

Association of graft neutrophil sequestration with delayed graft function in clinical renal transplantation

BACKGROUND: The authors studied the impact of neutrophil activation, detected in experimental models, on reperfusion injury in clinical renal transplantation. METHODS: Forty-five patients from a larger trial comparing three immunosuppressive protocols were recruited: perioperative antithymocyte globulin (ATG) with low initial cyclosporine A (CsA) triple therapy (group A, n=15); two-dose basiliximab with low initial CsA triple therapy (group B, n=16); and conventional triple therapy (group C, n=14). Blood samples were obtained preoperatively, before reperfusion, and at 1 and 5 min after reperfusion. During reperfusion, samples were collected from the iliac artery and the graft vein for calculation of transrenal differences (Delta) of study parameters. Leukocyte differential counts, plasma lactoferrin concentration, and neutrophil CD11b and L-selectin expressions were assessed. Graft blood flow was measured at 2 and 30 min after reperfusion. RESULTS: ATG induced neutrophil activation already before reperfusion. Thus, group A was excluded, but groups B and C were pooled for analysis of reperfusion-induced neutrophil activation. At 1 min after reperfusion, lactoferrin concentration was higher in graft vein than iliac artery, yielding Delta=15 microg/L (P<0.05). Concomitantly, Delta neutrophil count correlated with both Delta L-selectin expression (R=0.49, P=0.012) and graft blood flow at 2 min (R=0.51, P=0.007). At 5 min after reperfusion, 0.17 (-1.0-0.24)x10 cells/L neutrophils were sequestered in the graft (P<0.001). This sequestration correlated with graft blood flow at 30 min (R=0.53, P=0.005) and was stronger in patients with delayed graft function (DGF) (Delta = -0.38 [-1.45 to -0.2]) than those without (Delta = -0.12 [-0.41-0.24], P<0.001). In multiple regression analysis, sequestration was the most important parameter associated with DGF. CONCLUSIONS: Neutrophils are activated and sequestered in the reperfused graft during clinical renal transplantation. Neutrophil sequestration is a powerful independent factor explaining the incidence of DGF.     

Graft rinse prior to reperfusion in liver transplantation: literature review and online survey within the Eurotransplant community

Graft rinse prior reperfusion in liver transplantation (LT) is believed to reduce the incidence of postreperfusion syndrome and improve clinical outcome. A MEDLINE search was performed to obtain a comprehensive review of the published literature dealing with graft rinse in LT. Moreover, all thirty‐four LT centers in the Eurotransplant (ET) region were invited to participate in an online survey to whether or not graft rinse is performed and whether further research in the field is needed. Seventeen reports have been found to investigate graft rinse protocols in 1894 LT recipients. Eighteen of the thirty centers that participated in the online survey performed graft rinse prior reperfusion in LT. The most commonly used rinse solution was albumin. Nineteen centers stated interest in participating in a multicenter RCT in the field. The published literature does not provide concluding appraisal of the benefit of graft rinse in LT. Graft rinse protocols are not standardized and are based on personal experience. Appropriately designed clinical trials addressing the topic are demanded. The online survey appears to be a helpful tool for the evaluation of clinical practice and future research topics in the transplant community.     

Comparison of hepatic artery and portal vein reperfusion during orthotopic liver transplantation.

BACKGROUND: During orthotopic liver transplantation (OLT), it is standard procedure to reperfuse the liver via the portal vein (PV) despite having a lower oxygen content and perfusion pressure than the hepatic artery (HA). There are no published studies that describe graft function and outcome when the HA is used for reperfusion. We report a retrospective comparison of graft outcome after HA or PV reperfusion when the piggyback technique was used. METHODS: We identified 26 patients who had undergone OLT with HA reperfusion and 26 patients reperfused via the PV. Demographics, primary diagnosis, surgeon, warm and cold ischemic times, and blood product use were recorded. In each patient, whole blood lactate concentration, prothrombin time (PT), and alanine aminotransferase (ALT) were measured at defined time points during and after surgery as indices of graft lactate metabolism, synthetic function, and reperfusion injury, respectively. Thirty-day and 1-year outcome data were recorded. Data were compared between the HA and PV groups. RESULTS: Demographics, blood product use, primary diagnosis, cold ischemic time, and surgeon were similar between the groups. Warm ischemic time was longer in the HA group (mean [SD] HA 51.2 [14.7], PV 40 [9.1] min, P=0.002). Blood lactate concentrations were similar at all time points. There was no difference in 24-hr postoperative PT between the groups (median [InterQuartile (IQ) range] HA 17.5 [16-28.3], PV 19 [16-24] sec, P=0.85). Peak postoperative ALT values were comparable (median [IQ range] HA 1031 [668-1701], PV 1107 [754-1824] IU/ml, P=0.78). There were no statistically significant differences in 30-day or 1-year mortality, but more early deaths occurred in the HA group. Using our data, we calculated that a prospective randomized trial would need approximately 300 patients to be sure that mortality was the same with both techniques. CONCLUSION: We have demonstrated no clinically or statistically significant differences in indices of graft function, reperfusion injury, or outcome between primary HA or PV reperfusion.     

19例原位肝移植术中凝血弹性图变化及与ACT相关性的临床研究

目的 探讨国人原位肝移植术中凝血弹性图（TEG）的变化及其与激活全血凝块形成时间（ACT）的相关性。方法 19例病人分为急性肝衰组（8例）与肝肿瘤组（11例）,接受原位肝移植术,无肝期采用体外静脉－静脉转流。两组病人分别于术前、无肝前（手术开始后120min,I 120)、无肝的30min（Ⅱ 30）、新肝前5min（Ⅲ－5）、新肝后5min（Ⅲ＋5）、30min（Ⅲ＋30）、60min（Ⅲ＋60）、120min（Ⅲ＋120）,8个时间点,分别观察硅燥土激活的全血TEG及ACT的变化。19例病人中有6例于新肝后5min同时观察肝素酶修正后的TEG与非肝素酶修正后的TEG及ACT的变化。结果 肝衰组TEG值（r、r k、αlpha角或α、MA）的变化主要在Ⅱ＋30min、Ⅲ－5min、Ⅲ＋5min,肝肿瘤组TEG值（r、r k、αMA）的变化均在新肝后5min、30min、60min。与术前值相比,两组TEG值的表现为r与r k延长,α与MA减小（P＜0．05、0．01）。相关研究表明,两组r k与ACT均呈正相关（r分别为0．743及0．634,P＜0．01）。其中6例于新肝后5min,有肝素酶与无肝毒酶的全血TEG值差异亦显著（P＜0．01）,后者经静注鱼精蛋白50－75mg后,两组TEG值差异无统计学意义（P＞0．05）。结论 TEG提示原位肝移植术中的凝血紊乱主要发生在无肝期及新肝早期,TEG指标r k与ACT有相关性。肝素酶修正后的全血TEG可提示新肝期体内存在肝素化效应,需用鱼精蛋白拮抗。     

Goal directed preemptive ephedrine attenuates the reperfusion syndrome during adult living donor liver transplantation

BackgroundEnd-stage liver disease is associated with marked hemodynamic disturbances that are further deteriorated during liver transplantation and is aggressively represented in the form of postreperfusion syndrome (PRS).AimThe aim was to test the hypothesis that preemptive ephedrine administration pre-reperfusion targeting a rational level of mean arterial blood pressure (MAP) of 85–100 mmHg, may reduce the incidence of PRS.Patient and methodsOne hundred recipients for adult living donor liver transplantation (ALDLT) were prospectively randomized into 2 groups; group C, control group and group E, who received ephedrine 2.5–5 mg/min starting 5 min before reperfusion till mean arterial blood pressure (MAP) reached 85–100 mmHg. Hemodynamic parameters including MAP, heart rate (HR), Transesophageal Doppler (TED) parameters including corrected flow time (FTc), systemic vascular resistance (SVR), and cardiac output (COP) were measured; just predrug administration, just before reperfusion, just after reperfusion, 5 min after reperfusion and at the end of surgery. Cold and warm ischemia times (C/WIT), duration of anhepatic phase and total duration of surgery were recorded. The incidence of PRS, the need of rescue vasoconstrictor for hemodynamic instability at time of reperfusion, need for postreperfusion vasoconstrictor infusions, over shooting of hemodynamics, postreperfusion fibrinolysis indicated by fibrinogen level and maximum lysis parameter of rotational thromboelastometry (ROTEM) were compared between both groups.ResultsThe mean dose of ephedrine required was (12.5 ± 7.5 mg). Group E had statistically significant increase in MAP, SVR, and COP; just before reperfusion, just after reperfusion and 5 min after reperfusion readings. There were no statistical significant differences between the 2 groups at the end of surgery. The incidence of PRS and the need of rescue adrenaline at the time of reperfusion, and the postreperfusion need for vasoconstrictor infusion decreased significantly in group E when compared to group C. Also postoperative mechanical ventilation decreased significantly in group E.ConclusionThe preemptive goal directed titration of ephedrine against a target MAP pre-reperfusion could decrease the incidence of PRS by 40%, attenuated the hypotensive response to reperfusion and decreased the need for postreperfusion vasoconstrictor support without over shooting of any of the monitored hemodynamic indices.     

Pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, attenuates renal injury in an experimental model of ischemia-reperfusion.

BACKGROUND: Renal dysfunction due to ischemia-reperfusion (IR) injury is a common problem following renovascular surgery or kidney transplantation. There is a lot of emerging evidence that statins, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors, have anti-inflammatory properties and exert direct beneficial effects on the vascular endothelium. The aim of this study was to determine if pretreatment with pravastatin would attenuate the acute renal dysfunction that occurs following IR injury in an experimental model. MATERIALS AND METHODS: Male Sprague-Dawley rats were randomized into four groups (n = 7 per group): control, uninephrectomy, IR group, and IR group pretreated with pravastatin (0.4 mg/kg/day for the preceding 5 days). Following a left nephrectomy the IR injury was induced by cross-clamping the right vascular pedicle for 30 min followed by reperfusion for 2 h. In a separate experiment (n = 6 per group) renal function was assessed 12 and 24 h after reperfusion. RESULTS: IR injury causes significant renal dysfunction characterized by oliguria, 0.11 (0.05) ml/h, decreased glomerular filtration rate (GFR), 0.02 (0.01) ml/min; and marked protein leakage, 7.21 (1.3) g/L, 2 h postreperfusion. This renal dysfunction was also evident 12 and 24 h postreperfusion. This was in contrast to values of 0.61 (0.13) ml/h, 0.23 (0.01) ml/min, and 1.67 (0.12) g/L in the uninephrectomy-only group and values of 2 ml/h, 7.3 ml/min, and 0.72 g/L for uninjured time-matched controls. Pretreatment with pravastatin significantly attenuated IR-induced renal injury, improving urine production to 0.62 (0.2) ml/h and GFR to 0.14 (0.02) ml/min and diminishing protein leakage to 3.76 (0.7) g/L at the 2-h time point. This renoprotective effect was also evident 12 and 24 h postreperfusion. This renal protection was associated with an upregulation of constitutive endothelial nitric oxide synthase in the pravastatin-treated group. CONCLUSION: These results show that pravastatin may play a role in modulating renal impairment following aortic or transplantation surgery, allowing earlier recovery from an IR injury.     

Influence of endothelin-1 on hemodynamics during liver transplantation with and without temporary portocaval shunt: Results of a clinical randomized study

Aims of this study are to analyze the influence of endothelin-1 (ET-1) on hemodynamic evolution during liver transplantation (LT) and study the role of a temporary portacaval shunt in ET-1 synthesis. Forty LTs in patients with cirrhosis were studied. Two groups were analyzed: the first group had a temporary portacaval shunt during the anhepatic phase, and the second group did not. Portal and systemic ET-1 levels were measured at several times. At the end of the anhepatic phase, systemic (16.1 [plusmn] 6.5 pg/mL) and portal (19.2 [plusmn] 7 pg/mL) ET-1 levels increased, whereas they decreased after reperfusion (systemic, 11.8 [plusmn] 7.1 pg/mL; portal, 13.2 [plusmn] 6.8 pg/mL). Portal flow at the beginning of LT correlated with systemic ET-1 levels (R² = 0.3; P = .004). A temporary portacaval shunt reduced portal pressure during the anhepatic phase, but did not modify ET-1 levels. Patients with reperfusion syndrome had greater systemic ET-1 levels in the anhepatic phase (19.1 [plusmn] 6.9 v 15.1 [plusmn] 6.1 pg/mL; P = .07). Although there is a relationship between ET-1 levels and portal flow and reperfusion syndrome, no clear clinical effect on hemodynamics could be shown. Creation of a portacaval shunt made no change in ET-1 levels. (Liver Transpl 2002;8:27-33.)     

Reduced need for vasopressors in patients receiving aprotinin during orthotopic liver transplantation

BACKGROUND: Graft reperfusion in orthotopic liver transplantation is often associated with significant hemodynamic changes, including decreased systemic vascular resistance and arterial blood pressure. Vasopressive drugs are often required to maintain adequate perfusion pressure during the early postreperfusion period. The exact mechanism of this postreperfusion syndrome is unknown, but release of bradykinin, a potent vasodilatator, via the kallikrein system may play a role. Aprotinin is a broad-spectrum inhibitor of serine proteases such as kallikrein and therefore may ameliorate the postreperfusion syndrome and reduce the need for vasopressors. METHODS: In a randomized, double-blind study, the authors compared hemodynamic variables (systemic vascular resistance, cardiac index, arterial blood pressure, mean pulmonary artery pressure, central venous pressure) and the requirement of epinephrine during transplantation in 67 patients who received either high-dose aprotinin (2 x 10(6) kallikrein inhibitor units [KIU] at induction, continuous infusion of 1 x 10(6) KIU/h, 1 x 10(6) KIU before reperfusion; n = 24), regular-dose aprotinin (2 x 10(6) KIU at induction, continuous infusion of 0.5 x 10(6) KIU/h; n = 21), or placebo (n = 22). RESULTS: Baseline characteristics were similar for all three groups. Erythrocyte transfusion requirement was significantly higher in the placebo group compared with both aprotinin-treated groups. No major differences in hemodynamic variables were found between the three groups. The total amount of epinephrine (median, range) used during transplantation, however, was significantly lower in patients who received aprotinin (high dose, 20, 0-170 microg; regular dose, 30, 0-140 microg), compared with patients who received placebo (70, 0-2,970 microg; P = 0.0017). This difference was largely attributable to differences in the early postreperfusion period. CONCLUSIONS: Prophylactic use of aprotinin ameliorates the postreperfusion syndrome in orthotopic liver transplantation, as reflected by a significant reduction in vasopressor requirements.     

Acute blood leukocyte reduction after liver reperfusion: a marker of ischemic injury

INTRODUCTION: Reperfusion injury occurs after ischemic storage of the liver. The release of free radicals from endothelial cells leads to increased adherence of polymorphonuclear neutrophils to endothelium and further release of proteases and free radicals that alter the microcirculation and produce graft dysfunction. Acute blood leukocyte reduction after reperfusion may be an expression of this sequestration and activation of neutrophils within hepatic sinusoids. This study sought to evaluate whether reduction in white blood cells occurring immediately after reperfusion was a marker of poor graft preservation and postoperative dysfunction. METHODS: The leukocyte count was evaluated at the end of anhepatic phase and at 5 minutes after reperfusion among 65 patients undergoing liver transplantation. Group A included patients with a leukocyte reduction between the two phases greater than 50%; group B, patients with less than 50%. Hepatic enzymes, blood lactate (60 and 120 minutes after graft reperfusion) and factor V and VII and bilirubin levels (daily for 15 days after transplantation) were compared between groups to assess graft injury and postoperative dysfunction. RESULTS: Alanine aminotransferase levels were significantly higher among group A than group B at both 60 and 120 minutes after graft reperfusion. No differences were observed in lactate, and factor V and VII levels. Total bilirubin was significantly higher among group A than group B patients at 10 and 15 days postoperative. CONCLUSIONS: The acute blood leukocyte reduction after reperfusion, probably due to sequestration and activation into hepatic sinusoids, seemed to be an early intraoperative marker for poor graft preservation and function.     

Serum Vasopressin Concentrations During Orthotopic Liver Transplantation

Background

We report measurements of the temporal response of serum vasopressin concentrations in the period after reperfusion of the liver graft during orthotopic liver transplantation (OLT).

Methods

Vasopressin concentrations were determined in 11 adult patients undergoing OLT by radioimmunoassay of samples collected after induction, at 5 minutes prior to reperfusion, and at 10, 20, 30, 40, 50, 60, 90, and 120 minutes after reperfusion.

Results

Pre-incision vasopressin concentrations ranged from <0.5 to 2.6 pg/mL (reference serum vasopressin, <1.7 pg/mL). Overall, levels increased before reperfusion, but fell thereafter. Individual patients manifested elevated levels during the period after reperfusion. Values immediately before reperfusion exhibited most variability, ranging from 0.8 to 40 pg/mL (median, 15; interquartile range [IQR], 4-29) Median vasopressin concentrations 10 minutes postreperfusion were 7.6 pg/mL (IQR, 3-27). Only 3 of the 11 patients failed to generate vasopressin levels >20 pg/mL. In each of these patients, hemodynamics were satisfactory without the need for additional pressor infusion. Maximum vasopressin concentration measured in any patient was 85 pg/mL. There was no correlation between vasopressin concentration and mean blood pressure or systemic vascular resistance index.

Conclusion

Vasopressin concentrations during OLT vary widely and are elevated periodically during the anhepatic and postreperfusion stages, with no apparent relationship between vasopressin concentrations and blood pressure. Although vasopressin concentrations were not as high as those measured during some other clinical situations, these data suggest that a relative vasopressin deficiency is not a direct cause of hypotension during OLT.     

The Comparison of Mitogen-Activated Protein Kinases That Become Activated Within the Left Ventricular and Right Atrial Tissues Following Heart Transplantation in Canine Model

The activation of p38 mitogen-activated protein kinase (MAPK) plays an important role in ischemia/reperfusion injury. Some reports have documented MAPKs activation of the myocardium in human models, using right atrial (RA) tissue for samples. This study compared the activation of MAPKs in left ventricle (LV) and RA tissues in canine heart transplantation. Four dogs were used as baseline data at two points, before and 20 min after warm ischemia (baseline model), and eight dogs (four pairs of donor and recipient) were used at other points: 4 h after cold ischemia, and at 10, 60, and 180 min after reperfusion (transplantation model). In the transplantation model, donor hearts were left in situ for 20 min after cardiac arrest, and were immersed in Celsior solution for 4 h after coronary flushing. Orthotopic heart transplantation was then performed. Two groups were created: the LV and RA groups (n = 4 in each group). Heart tissue was harvested from the left ventricular wall in the LV group and from the right atrial appendage in the RA group. The activation of MAPKs, including p38 MAPK, c-Jun N-terminal protein kinase (JNK), and extracellular signal-regulated protein kinase (ERK), was evaluated at each point. The activation patterns of p38 MAPK and ERK were similar in the RA and LV groups, but JNK activation was different in the two groups, after ischemia and reperfusion. Thus, RA tissue may be deliberately used as a substitute for LV tissue when investigating the activation of MAPKs in a human model.     

The comparison of mitogen-activated protein kinases that become activated within the left ventricular and right atrial tissues following heart transplantation in canine model.

The activation of p38 mitogen-activated protein kinase (MAPK) plays an important role in ischemia/reperfusion injury. Some reports have documented MAPKs activation of the myocardium in human models, using right atrial (RA) tissue for samples. This study compared the activation of MAPKs in left ventricle (LV) and RA tissues in canine heart transplantation. Four dogs were used as baseline data at two points, before and 20 min after warm ischemia (baseline model), and eight dogs (four pairs of donor and recipient) were used at other points: 4 h after cold ischemia, and at 10, 60, and 180 min after reperfusion (transplantation model). In the transplantation model, donor hearts were left in situ for 20 min after cardiac arrest, and were immersed in Celsior solution for 4 h after coronary flushing. Orthotopic heart transplantation was then performed. Two groups were created: the LV and RA groups (n = 4 in each group). Heart tissue was harvested from the left ventricular wall in the LV group and from the right atrial appendage in the RA group. The activation of MAPKs, including p38 MAPK, c-Jun N-terminal protein kinase (JNK), and extracellular signal-regulated protein kinase (ERK), was evaluated at each point. The activation patterns of p38 MAPK and ERK were similar in the RA and LV groups, but JNK activation was different in the two groups, after ischemia and reperfusion. Thus, RA tissue may be deliberately used as a substitute for LV tissue when investigating the activation of MAPKs in a human model.     

Correlation of hepatic injury, synthetic function, and mitochondria energy level in orthotopic liver transplantation.

The arterial ketone blood ratio (AKBR) of acetoacetate to b-hydroxybutyrate was previously shown to reflect hepatic mitochondria oxidation/reduction (redox) state and energy level. In this study we correlated AKBR to the degree of liver injury immediately following orthotopic liver transplantation (OLT). Serial measurements of AKBR in 209 patients undergoing OLT, during the anhepatic phase, and up to 60 hr following reperfusion demonstrated direct correlation between mitochondria Redox state (AKBR), hepatocyte injury (SGOT), and hepatic synthetic function (prothrombin time). AKBR levels less than 0.7 were seen in primary nonfunction grafts and were associated with raising SGOT (greater than 1000) and prolonged PT (greater than 18). Acute occlusion of arterial blood supply to the graft was seen in conjunction with low AKBR (less than 0.7). However, hepatic synthetic function and serum enzyme were stabilized or returned to normal within 24-48 hr postreperfusion. In conclusion: (1) AKBR measurements are useful in predicting graft survival, (2) reduction in liver mitochondria Redox state is seen in primary hepatocyte dysfunction and correlates well to synthetic function, and (3) acute occlusion of the arterial supply to the liver graft is associated with decreased redox state. However, with intact portal blood flow, it is still possible to preserve adequate hepatic synthetic function.     

体外静脉-静脉转流下原位肝移植术病人体、肺循环的变化

目的观察体外静脉-静脉转流下原位肝移植体肺循环血液动力学的变化。方法20例原位肝移植手术病人,在无肝期采用体外静脉-静脉转流术,采用Swaan-Ganz漂浮导管监测不同时期体、肺循环血液动力学的变化。结果与基础值相比,手术期间MAP基本稳定;中心静脉压(CVP)、心输出量(CO)、心脏指数(CI)、左心功指数(LVSW)和右心功指数(RVSW),在转流期间有降低,在开放后新肝期15分钟有增高(P<0．05);肺动脉压(PAP)和肺毛细血管楔压(PAWP)在新肝期15分钟一定增加(P<0．05);体循环阻力(SVR)在无肝期增高,在新肝期15分钟降低(P<0．05);肺血管阻力(PVR)在新肝期15分钟增高;心率在转流期间加快(P<0．05)。结论原位肝移植手术中,在无肝期采用体外静脉-静脉转流术有助于血压的稳定,但体、肺循环血流动力学在无肝期和新肝早期仍有明显的变化。     

Adipose Gene Expression Profile Changes With Lung Allograft Reperfusion

Obesity is a risk factor for primary graft dysfunction (PGD), a form of lung injury resulting from ischemia–reperfusion after lung transplantation, but the impact of ischemia–reperfusion on adipose tissue is unknown. We evaluated differential gene expression in thoracic visceral adipose tissue (VAT) before and after lung reperfusion. Total RNA was isolated from thoracic VAT sampled from six subjects enrolled in the Lung Transplant Body Composition study before and after allograft reperfusion and quantified using the Human Gene 2.0 ST array. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed enrichment for genes involved in complement and coagulation cascades and Jak‐STAT signaling pathways. Overall, 72 genes were upregulated and 56 genes were downregulated in the postreperfusion time compared with baseline. Long pentraxin‐3, a gene and plasma protein previously associated with PGD, was the most upregulated gene (19.5‐fold increase, p = 0.04). Fibronectin leucine‐rich transmembrane protein‐3, a gene associated with cell adhesion and receptor signaling, was the most downregulated gene (4.3‐fold decrease, p = 0.04). Ischemia–reperfusion has a demonstrable impact on gene expression in visceral adipose tissue in our pilot study of nonobese, non‐PGD lung transplant recipients. Future evaluation will focus on differential adipose tissue gene expression and the development of PGD after transplant.     

Intragraft coagulation events and delayed graft function in clinical renal transplantation

BACKGROUND: Cold preservation, reperfusion damage, immunosuppressive drugs, and uremia-induced acquired thrombophilias increase the risk of thrombotic complications in renal transplantation. Intragraft fibrin deposition may be associated with delayed graft function. METHODS: We studied coagulation and fibrinolysis in 45 patients of a larger trial in renal transplantation: perioperative antithymocyte globulin (group A, n=15), perioperative basiliximab (group B, n=16), and conventional triple therapy (group C, n=14). Blood samples for prothrombin fragment F1+2, plasminogen activator inhibitor (PAI)-1, d-dimer, tPA antigen, tPA activity, and platelet counts were obtained simultaneously at 1 and 5 min after reperfusion from iliac artery and graft vein for calculation of transrenal changes. Because antithymocyte globulin activates coagulation and fibrinolysis, group A was analyzed separately. Groups B and C were pooled (group BC). RESULTS: In group BC, transrenal D-dimer release occurred at 1 min, tPA-antigen release at 1 and 5 min, and transrenal PAI-1 uptake at 5 min postreperfusion. tPA activity increased marginally only at 1 min. High graft tPA-antigen release at 5 min and D-dimer release at 1 min were associated with delayed graft function. In group A, transrenal tPA-antigen release occurred at 1 and 5 min and D-dimer release at 1 min. There were no transrenal F1+2 changes in either group. CONCLUSION: Although graft PAI-1 uptake inhibits tPA activity, graft releases D-dimer at early reperfusion without concomitant F1+2 release. Data suggest thrombin and fibrin formation already before cold preservation during donor care and organ retrieval. This fibrin deposition increases risk of delayed graft function.