Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A review of 550 consecutively transplanted liver grafts stored in University of Wisconsin solution (UW) was performed during a 4-year period to ascertain whether graft function was impaired by flushing the aorta with Eurocollins (EC) rather than UW during the harvesting. The outcome of 255 liver grafts flushed with UW in both the aorta and portal vein (group UW/UW) was compared with 295 liver grafts flushed with EC through the aorta and UW through the portal vein (group ECUW). Liver grafts in both groups were flushed with 1 L of UW during the back table procedure and subsequently stored in UW at 4 degrees C before transport. Donor and recipient characteristics, cold and warm ischemia times, and methods of transplantation were similar in both groups, except that the recipient prothrombin time (PT) before liver transplantation (LT) was lower in the UW/UW group. There was no significant difference between the groups with peak transaminases aspartate aminotransferase (AST) and alanine aminotransferase, maximum value of serum bilirubin within 10 days following LT, incidence of primary nonfunction, need for retransplantation, and patient and graft survival at 1 month. Results were improved, however, in the EC/UW group in regard to PT after LT, operative bleeding and proportion of grafts with histologic lesions at the reperfusion biopsy (P<0.001). These better results in the EC/UW group were confirmed when grafts transplanted in urgent situations were excluded from analysis and by multivariate analysis assessing the effects of pretransplant PT and AST values of the recipients combined with the method of liver cooling with each of the aforementioned criteria. In conclusion, the method of using EC for the aortic flush during liver procurement reduces the amount of UW solution by 50% with improved graft function. This method seems justified in that it is less expensive while affording improved graft function.
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PMID:Beneficial effects of Eurocollins as aortic flush for the procurement of human livers. 860 71

Liver cooling before grafting is usually achieved by aortic plus portal flushing; exclusively aortic flushing is reserved to hemodynamically unstable or non heart-beating donors. We have compared the effects of "aortic plus portal" (8 cases) and "aortic" (8 cases) cold flushing on the early function of pig liver grafts from hemodynamically stable donors. The time for liver removal (mean +/- standard deviation) was 30.4 +/- 7.1 min. in the "aortic plus portal" and 19.7 +/- 3.3 min. in the "aortic" group (p < 0.01). All the recipients survived for at least 72 hrs; only those of the "aortic plus portal" group showed some degree of primary liver dysfunction; recipient serum aspartate transaminase (AST) was significantly higher in the "aortic plus portal" than the "aortic" group. Since aortic flushing allowed for shorter operation times and was better tolerated than and at least as effective as aortic plus portal flushing, it can be proposed for routine liver procurement even from hemodynamically stable donors.
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PMID:Exclusively aortic cold flushing for liver procurement from hemodynamically stable donors. An experimental study in the pig. 867 17

Between March 1991 and August 1995, 36 livers from donors >/=70 years old were transplanted. In donors, we recorded the following risk factors: alanine aminotransferase > 120 and rising, dopamine dose > 15 microg/kg/min, hypotension (systolic blood pressure <80) >1 hr, stay in the intensive care unit >5 days and body mass index >/=27. In 35 recipients, we recorded pretransplant United Network for Organ Sharing (UNOS) status, cold/warm ischemia time, intraoperative blood loss, and occurrence of poor early graft function or primary nonfunction. Mean recipient age was 55 years (range, 25-75 years). Four recipients were UNOS status 1, 19 were UNOS 2, and 12 were UNOS 3. Two livers were used as second grafts for primary graft nonfunction. Mean donor age was 73 years (range, 70-84 years). Intracranial bleeding was the cause of death in the majority of donors. The 36 donors had 40 risk factors; 10 donors had >1 risk factor. Mean cold and warm ischemia times were 9:08 +/- 2:57 hr and 51 +/- 9 min. Mean total operative time was 7.5 hr. Posttransplant mean peak alanine aminotransferase and aspartate aminotransferase levels were 937.3 +/- 703.1 IU/L and 923.3 +/- 708.5 IU/L, respectively. Mean prothrombin time on postoperative day 2 was 14.9 +/- 1.6 sec. Average total bilirubin on postoperative day 5 was 4.9 mg/dl. Median length of stay in the intensive care unit was 4 days. One recipient had poor early graft function; two recipients had primary nonfunction. Mean follow-up was 503 days (range, 110-1714 days). Three-month actual graft and patient survival rates were 85% and 91%, respectively. One-year actuarial graft and patient survival rates were also 85% and 91%, respectively. We conclude that older livers can be used safely. Advanced donor age should not be a contraindication to liver procurement.
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PMID:Safe use of hepatic allografts from donors older than 70 years. 869 47

The uptake of hyaluronic acid (HA) was used to assess preservation damage to sinusoidal endothelial cells (SEC) during cold storage and subsequent normothermic reperfusion of rat livers. After 8, 16, 24, and 48 h storage in University of Wisconsin (UW) solution, livers were gravity-flushed via the portal vein with a standard volume of cold UW solution containing 50 micrograms/l HA. The effluent was collected for analysis of HA, aspartate aminotransferase (AST), and lactate dehydrogenase (LDH). The mean uptake of HA at 0 h was 59.1% +/- 4.6% (mean +/- SEM). After 8 h of storage, HA uptake was similar (55.5% +/- 7.3%), whereas after 16 h of storage it was reduced to 34.7% +/- 5.8%. At 24 and 48 h of storage, no uptake of HA was found. In a second series of experiments, livers were stored in UW solution and subsequently reperfused for 90 min with a Krebs-Henseleit solution (37 degrees C) in a recirculating system containing 150 micrograms/l HA. Following 8 h of storage, 34.6% +/- 8.0% of the initial HA concentration was taken up from the perfusate. After 16 and 24 h of storage, no uptake of HA was found. The results of this study indicate that damage to SEC occurs progressively during storage, leading to zero uptake of HA by the rat livers at 24 h of cold ischemia time. Additional reperfusion injury to the SEC was demonstrated by the reduced ability of the SEC to take up HA following normothermic reperfusion. The uptake of exogenous HA in preserved livers, used as a tool to assess SEC injury, enables the detection of early preservation damage.
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PMID:Hyaluronic acid uptake in the assessment of sinusoidal endothelial cell damage after cold storage and normothermic reperfusion of rat livers. 887 86

In 50 human livers harvested for transplantation, injury was assessed by determination of liver enzymes (lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, glutamate dehydrogenase, and creatine kinase) and of thrombomodulin in the effluent perfusate after cold ischemia. The results were compared with the morphology and the clinical course after transplantation. Whereas the release of the markers of endothelial cell injury correlated neither with the history of the graft nor with the postoperative course, the release of hepatocellular enzymes into the perfusate did indicate the severity of liver injury, even when biopsy showed normal liver tissue. Seven of 12 livers with high activities of hepatocellular enzymes in the effluent (activity of more than twice the median) showed delayed onset of function or primary nonfunction. In the other 38 livers with enzyme activities below this borderline, no delayed functioning or primary nonfunction was observed. Thus, determination of liver enzyme activities in the effluent makes it possible to identify those livers in which initial nonfunction is very unlikely, a potential that is especially valuable in livers shown by anamnesis or morphology to be of borderline quality.
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PMID:Determination of hepatocellular enzymes in effluent of human liver grafts for preoperative evaluation of transplant quality. 893 67

Eighty liver allografts were studied to determine the predictive value of intraoperative biopsies and postoperative liver function tests for the development of preservation injury (PI). Peak transaminase (aspartate transaminase [AST] and alanine transaminase [ALT]) and prothrombin time (PT) values achieved by each patient during postoperative days (POD) 1 through 7 were determined. PI in day 0 preperfusion biopsies (0Pre) (obtained immediately before implantation) and postperfusion biopsies (0Post) (obtained immediately after revascularization) was categorized by histological criteria as present or absent. PI in biopsies taken during POD 2 through 14 was histologically graded as either moderate-to-severe, mild, or absent. Of the 80 allografts, 8 were omitted because of primary nonfunction or postoperative complications. 0Pre and 0Post biopsies were available on 25 of 72 (35%) and 69 of 72 (96%) allografts, respectively. Only 2 (8%) of the 0Pre biopsies showed histological PI compared with 48 (70%) of the 0Post biopsies. Fifty-nine patients were biopsied between POD 2 through 14. Of these, 15, 28, and 16 patients developed moderate-to-severe, mild, or no evidence of PI, respectively. The presence of PI in the 0Post biopsy strongly correlated with the development of PI during POD 2 through 14 (P < .0005). Peak AST and ALT values in patients with moderate-to-severe PI on POD 2 through 14 were significantly elevated compared with those patients with either mild (P = .01 and .03) or no PI (P = .02 and .006). Because of extensive overlap in AST and ALT values between the three groups, however, transaminase values were not useful in predicting the presence or absence of PI in the individual case. The development of PI during POD 2 through 14 correlated with advanced donor age (P = .06) but was unassociated with 0Pre biopsy findings, cold ischemia time, or peak PT values. We conclude that the 0Post biopsy is a valuable tool for the prediction of subsequent PI in the early postoperative period. In contrast, 0Pre biopsy findings and peak AST and ALT values are not useful in the assessment of PI.
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PMID:Predictive value of intraoperative biopsies and liver function tests for preservation injury in orthotopic liver transplantation. 898 88

Activated Kupffer cells (KC) have been implicated in the damage sustained by preserved liver grafts during ischemia and reperfusion. The aim of this study was to compare ischemia/reperfusion injury in preserved, KC-depleted rat livers and preserved control livers, with special regard to sinusoidal endothelial cell (SEC) injury. Wistar rats were injected with liposome-encapsulated dichloromethylene diphosphonate, 48 hr before hepatectomy, to eliminate KC, or were withheld this pretreatment (controls). Livers were flushed with cold University of Wisconsin solution and after 0, 8, 16, or 24 hr of storage at 4 degrees C, were reperfused in a recirculation system with 200 ml of oxygenated Krebs-Henseleit solution at 37 degrees C for 90 min. Damage to SEC was measured by the uptake of hyaluronic acid (HA) from the perfusate and release of purine nucleoside phosphorylase (PNP). Perfusate samples were, furthermore, analyzed for aspartate aminotransferase (AST) and tumor necrosis factor-alpha. Carbon particles were infused in the perfusate to determine the phagocytotic capacity of KC. Biopsies were taken for histological examination and sections were stained with ED2 monoclonal antibodies to confirm the absence of KC. After 90 min of reperfusion, immediately after cold flush (t0), the uptake of HA was 72.2+/-2.3% and 69.3+/-1.3% in KC-depleted livers and in control livers, respectively (n.s.). After 8 hr of storage, HA uptake was 21.6+/-4.5% and 34.6+/-8.0%, respectively (n.s.). After 16 and 24 hr of storage and reperfusion, no uptake of HA was found in either KC-depleted or control livers, indicating abolished SEC function. PNP activities in the perfusate were higher in control livers (after 8 and 24 hr of storage), presumably due to release from damaged KC. No difference was found in AST and no tumor necrosis factor-alpha was measured in the perfusates of normal and KC-depleted livers. Electron microscopic studies showed that after 8 and 24 hr of storage and reperfusion, KC were activated and were able to phagocytose colloidal carbon. Our conclusion was that the elimination of Kupffer cells did not result in reduction of ischemic and reperfusion damage in livers preserved up to 24 hr, as assessed in vitro by SEC uptake of HA, PNP release, and AST release.
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PMID:No attenuation of ischemic and reperfusion injury in Kupffer cell-depleted, cold-preserved rat livers. 903 38

Shortage of organ donors presents a perplexing problem in liver transplantation, and improved methods for evaluating the viability of organs prior to implantation are urgently needed. In the present study, the hypothesis was evaluated that grafts from fatty livers release more amino acids than non-fatty controls during organ harvest. Amino acids in graft rinse effluents at the time of harvest and after cold storage were measured by reverse-phase high performance liquid chromatography and compared with plasma aspartate aminotransferase (AST) levels and recipient survival. Twenty-four hours after transplantation of fatty livers, AST levels in recipient rats were increased more than two-fold compared to non-fatty controls (p < 0.01). Survival in the control group was 83 percent, whereas animals receiving fatty livers from ethanol-treated rats survived no longer than 7 days after transplantation (p < 0.05). The rate of release of amino acids from the liver explant was two-fold higher during the harvest procedure (0.5 h) than during the subsequent 23.5 hour cold storage period (435 +/- 70 vs. 186 +/- 14 nmol/ml/hr/g liver, p < 0.001). Further, in the early rinse effluent, amino acids were released about two-fold faster from fatty livers than from controls (p < 0.05). This study demonstrates that the release of amino acids from liver explants increases during the harvesting procedure and is about two-fold higher in fatty livers which fail after transplantation than in surviving controls. It is proposed that amino acid release from explants after organ harvest might serve as a useful marker to evaluate graft function prior to transplantation.
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PMID:Release of amino acids from fatty livers during organ harvest for transplantation. 921 Sep 74

We measured enzyme activities along a heterothermic tissue, the visceral retia mirabilia of the bluefin tuna, to test current theories of enzyme temperature adaptation. The heterothermic tissue model is ideal for the study of fundamental temperature adaptation because it eliminates confounding effects of whole animal acclimation. Enzymes were measured at six positions along the rete at four temperatures (15, 20, 25, and 30 degrees C). Five enzymes (aspartate aminotransferase, citrate synthase, glucose-6-phosphate dehydrogenase, glutamate dehydrogenase, and pyruvate kinase) exhibited a significant positive compensatory effect, with activity at the cold end of the rete 1.2-3.1 times higher than at the warm end. Two enzymes (alanine aminotransferase and lactate dehydrogenase) exhibited no significant compensation. On the basis of activation energies of enzymes along the rete, differences in activity were due to differences in enzyme concentration and not isozymes or enzyme modification. Analysis of the compensatory responses of the enzymes in light of their thermal sensitivities leads us to conclude that the pentose phosphate shunt is especially enhanced at the cold end of the rete.
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PMID:Enzyme adaptation along a heterothermic tissue: the visceral retia mirabilia of the bluefin tuna. 922 97

Proteases as well as alterations in intracellular calcium have important roles in hepatic preservation-reperfusion injury, and increased calpain activity recently has been demonstrated in liver allografts. Experiments were designed to evaluate (i) hepatic cytosolic calpain activity during different periods of cold ischemia (CI), rewarming, or reperfusion, and (ii) effects of inhibition of calpain on liver graft function using the isolated perfused rat liver and arterialized orthotopic liver transplantation models. Calpain activity was assayed using the fluorogenic substrate Suc-Leu-Leu-Val-Tyr-7-amino-4-methyl coumarin (AMC) and expressed as mean +/- SD pmol AMC released/min per mg of cytosolic protein. Calpain activity rose significantly after 24 hr of CI in University of Wisconsin solution and further increased with longer preservation. Activity also increased within 30 min of rewarming, peaking at 120 min. Increased durations of CI preceding rewarming resulted in significantly higher activity (P < 0.01). Calpain activity increased rapidly upon reperfusion and was significantly enhanced by previous CI (P < 0.01). Calpain inhibition with Cbz-Val-Phe methyl ester significantly decreased aspartate aminotransferase released in the isolated perfused rat liver perfusate (P < 0.05). Duration of survival after orthotopic liver transplantation using livers cold-preserved for 40 hr was also significantly increased (P < 0.05) with calpain inhibitor. In conclusion, calpain proteases are activated during each phase of transplantation and are likely to play an important role in the mechanisms of preservation-reperfusion injury.
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PMID:Calpain is a mediator of preservation-reperfusion injury in rat liver transplantation. 925 86


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