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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Because of the unique demographics of our patient population, we have had the opportunity to dedicate further studies of the management of hepatitis B and hepatitis C. We have experienced a very low HBV recurrence rate with the use of HBIG in patients transplanted for hepatitis B. Investigations, including the use of new antiviral agents, and the development of approaches to minimize or abrogate disease recurrence such as lower levels of immunosuppression are ongoing. Using a standardized approach to the proper evaluation and selection of patients for liver transplantation with alcoholic liver disease or other liver diseases with coexistent alcohol abuse, we report favorable long-term results in these patients. We have reviewed our results and our approach to the management of EBV and posttransplant lymphoproliferative disorder. There is a firm commitment in our laboratories and outpatient clinics to the investigation of disease prevention, reliable detection and screening methods, and treatment modalities for EBV-related disease. We have addressed specific technical considerations to pediatric liver transplant and have discussed unique aspects of postoperative management in these patients. One-third of the transplants performed at Stanford are in children, 42% of whom are less than one year old. Results with our pediatric transplant recipients compare favorably with those of our adult recipients with patient and graft survival rates approaching 90% at one year and exceeding 80% at 46 months for both groups. As a response to the limited organ supply, we have extended our criteria for suitable donors. Most notably, we have utilized older donors and grafts with significant microsteatosis and have observed good results with these grafts as long as ischemia time is minimized. We have also successfully used reduced size grafts for our pediatric patients with good results and are continuing to expand the use of living-related partial grafts and split allografts.
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PMID:Liver transplantation at Stanford University Medical Center. 1050 6

The occurrence of acute cellular rejection after orthotopic liver transplantation is common. At present, no allowance is made in immunosuppressive regimens for parameters other than weight. We investigated parameters in 121 consecutive patients receiving their primary allograft to determine if there are pretransplantation factors predicting the occurrence of acute cellular rejection after transplantation. The case notes and dietetic notes of these patients were reviewed for age at transplantation, cause of liver disease, preoperative albumin and creatinine levels, lymphocyte count, anthropometric measurements, donor age, HLA DR mismatch, and cold ischemia time. Acute cellular rejection was more likely to occur in younger patients, patients with Child's class A disease, and those with normal midarm muscle circumference. Acute rejection was increased in transplant recipients from donors aged younger than 30 and older than 50 years. Acute cellular rejection was less likely to occur in patients who underwent transplantation for alcoholic liver disease. Chronic rejection was significantly increased in women and those patients who experienced recurrent acute rejection. On multivariate analysis, the only significant predictor was the decreased likelihood of acute rejection in patients with depleted midarm muscle circumference. In conclusion, it may be possible to individualize immunosuppressive regimens on the basis of pretransplantation characteristics.
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PMID:The prediction of acute cellular rejection in orthotopic liver transplantation. 1054 33

The majority of patients undergoing orthotopic liver transplantation (OLT) have end-stage liver disease secondary to hepatitis C virus (HCV) infection. Although OLT does not cure the disease and recurrent virus is present in all patients, relatively few patients with recurrent viremia develop clinical disease. When the disease recurs, however, the results can be devastating. Factors associated with increased risk for recurrent HCV disease remain controversial. We hypothesized that preservation injury may predispose to the severity of HCV disease after OLT. We reviewed our series of OLTs performed for HCV cirrhosis between January 1994 and December 1998 (n = 56; 62 transplants). Patients were grouped according to the severity of recurrent hepatitis C. Group 1 had no or mild HCV disease (n = 36), and group 2 had moderate to severe HCV disease (n = 20). The duration of ischemic rewarming during graft implantation was significantly associated with the severity of recurrent hepatitis C (P <.04). The estimated chances of severe disease within the first year post-OLT after 30, 60, or 90 minutes of ischemic rewarming time were 19%, 40%, and 65%, respectively. Cold ischemia time, transaminase levels, and prothrombin time did not correlate with the severity of hepatitis C. In conclusion, our data suggest that the duration of ischemic rewarming predisposes to severe recurrent hepatitis C. This finding warrants the investigation of the pathogenesis of recurrent HCV disease after ischemic injury. Reduction of rewarming time should be stressed in OLT, particularly in patients with HCV cirrhosis.
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PMID:Prolonged rewarming time during allograft implantation predisposes to recurrent hepatitis C infection after liver transplantation. 1091 61

Transplants and centers Between 1988 and 1998 the number of liver transplants performed in the US more than doubled from 1,713 to 4,487; the number of centers increased from 59 to 116. The number of living donor, segmental, and multiple organ transplants also increased over time. The rate of increase in the number of centers has slowed over the last few years. Outcomes. Survival among pediatric recipients. The one- and 7-year graft survival rates for pediatric recipients were 72% and 62%, respectively. The one- and 7-year patient survival rates were 85% and 79%. Patient survival did not decrease much after the first 2 years and graft survival stabilized after 4 years posttransplant. Some of the factors associated with increased odds of graft failure and patient death at 6 months posttransplant included having a previous transplant; being hospitalized, in the ICU, or on life support at the time of transplant; creatinine > 2 mg/dl; donor age and race/ethnicity; and transplant type. Factors associated with decreased odds of graft failure or patient death were recipient gender, recipient race/ethnicity, having a metabolic disease and receiving a living donor liver. Among grafts/recipients surviving the first 6 months after transplantation, recipient race/ethnicity, primary liver disease, having a previous transplant, donor age and race/ethnicity, and transplant type were associated with a greater relative risk of graft failure and mortality. Survival among adult recipients. The one- and 7-year graft survival rates among adult recipients were 77% and 57%, respectively. The one- and 7-year patient survival rates were 85% and 67%. Survival rates decreased steadily at all time points following transplantation. Some of the factors associated with increased odds of graft failure and mortality at 6 months after transplantation were recipient age and race/ethnicity; primary liver disease; having a previous transplant; being hospitalized, in the ICU, or on life support at the time of transplant; longer cold ischemia time; older donor age, race/ethnicity, or gender; and having a non-identical recipient/donor blood type match. Having cholestatic liver disease/cirrhosis and shorter cold ischemia times were associated with decreased odds of graft failure and mortality. Many of these characteristics also affected grafts and patients surviving the first 6 months, including recipient race/ethnicity, primary liver disease, previous transplant, and donor age.
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PMID:Liver transplantation in the United States: a report from the UNOS Liver Transplant Registry. 1103 23

Normothermic ischemia and reperfusion of the liver results in microcirculatory failure followed by necrosis and cell death. Recently, another type of cell death, apoptosis or programmed cell death, was found to be activated during the early phase of reperfusion after liver ischemia. Caspases are cysteine proteinases specifically involved in the initiation and execution phases of apoptosis. The aim of this study was to demonstrate that inhibition of apoptosis by a specific inhibitor of caspases might protect the liver against ischemia/reperfusion injury. Rats were divided into three groups: group 1, control, PBS administration; group 2, Z-Asp-cmk (Z-Asp-2,6-dichlorobenzoyl-oxymethylketone) treatment; group 3, sham-operated control animals. Z-Asp-cmk (0.5 mg Z-Asp-cmk dissolved in 300 microl PBS solution containing 1% DMSO) was injected intravenously, 2 min prior to induction of 120 min ischemia. Survival rates were compared and serum activities of aspartate aminotransferases and alanine aminotransferases were assessed in the blood collected from the suprahepatic vena cava. Histology of the liver was assessed 6 h after the end of ischemia. Apoptosis was detected by the terminal deoxynucleotidyl transferase-mediated dUTP-FITC nick end-labeling method (TUNEL method) and by electrophoresis for analysis of DNA fragmentation. Caspase activity was determined by measuring hydrolysis of the CPP32-like substrate Ac-DEVD-pNA and absorption of paranitroaniline. Z-Asp-cmk treatment significantly increased 7-day survival (95%) compared with that in nontreated rats (30%, P < 0.001). Serum activities of aminotransferases and the extent of liver congestion and necrosis were significantly (P < 0.001) decreased after treatment with Z-Asp-cmk. TUNEL-positive cells were detected 3-6 h after reperfusion in the control group. In Z-Asp-cmk pretreated rats, a dramatic decrease in the number of TUNEL-positive cells was observed. Analysis of DNA fragmentation of freshly isolated hepatocytes confirmed these results. Caspase activity was increased 3-6 h after reperfusion in the control group, but significantly (P < 0.001) decreased after treatment with Z-Asp-cmk. These findings demonstrate that liver injury following ischemia and reperfusion can be prevented by inhibition of caspases. Caspase inhibitors may have important implications for therapy in liver disease and after liver transplantation.
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PMID:Caspase inhibition protects from liver injury following ischemia and reperfusion in rats. 1111 76

Apoptosis, or programmed cell death, and the elimination of apoptotic cells are crucial factors in the maintenance of liver health Apoptosis allows hepatocytes to die without provoking a potentially harmful inflammatory response In contrast to necrosis, apoptosis is tightly controlled and regulated via several mechanisms, including Fas/Fas ligand interactions, the effects of cytokines such as tumor necrosis factor alpha (TNF-alpha) and transforming growth factor beta (TGF-beta), and the influence of pro- and antiapoptotic mitochondria-associated proteins of the B-cell lymphoma-2 (Bcl-2) family. Efficient elimination of apoptotic cells in the liver relies on Kupffer cells and endothelial cells and is thought to be regulated by the expression of certain cell surface receptors. Liver disease is often associated with enhanced hepatocyte apoptosis, which is the case in viral and autoimmune hepatitis, cholestatic diseases, and metabolic disorders. Disruption of apoptosis is responsible for other diseases, for example, hepatocellular carcinoma. Use and abuse of certain drugs, especially alcohol, chemotherapeutic agents, and acetaminophen, have been associated with increased apoptosis and liver damage. Apoptosis also plays a role in transplantation-associated liver damage, both in ischemia/reperfusion injury and graft rejection. The role of apoptosis in various liver diseases and the mechanisms by which apoptosis occurs in the liver may provide insight into these diseases and suggest possible treatments.
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PMID:Apoptosis in diseases of the liver. 1134 18

Liver surgery and liver transplantation as well as circulatory shock are often associated with hepatic ischemia/reperfusion (I/R) injury. Recent evidence suggests that TNF-alpha plays a central role in I/R injury and, therefore, down-regulation of TNF-alpha seems to be a promising way to protect against the deleterious consequences of I/R. Endotoxin tolerance represents a state of unresponsiveness to endotoxin and is associated with diminished TNF-alpha production. Thus, the effect of endotoxin tolerance on hepatic I/R injury of the liver was investigated in a rat model. I/R injury was induced by temporary ischemia of the left lateral liver lobe for 90 min followed by a 3 h observation period of reperfusion. I/R injury resulted in functional hepatic disorder characterized by a decrease both in bile flow and bile acid concentration and 50% mortality. This was prevented by induction of endotoxin tolerance. Hepatic TNF-alpha mRNA expression after I/R of the liver was determined by RT-PCR. In untreated rats, TNF-alpha mRNA was induced in the liver 60 min after reperfusion and further increased until 3 h after reperfusion. In contrast, in endotoxin-tolerant rats, no increases in TNF-alpha mRNA expression were detected. This suggests that induction of endotoxin tolerance protects against hepatic I/R injury possibly via down-regulation of intra-organ TNF-alpha expression.
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PMID:Endotoxin tolerance protects against local hepatic ischemia/reperfusion injury in the rat. 1152 Oct 53

Orthotopic liver transplantation has become the treatment of choice for patients with end-stage nonmalignant liver disease. The surgical techniques and immunosuppressive therapy for this procedure have improved considerably. Nevertheless, there are still significant complications, particularly those of vascular origin, which can lead to graft failure and require retransplantation unless prompt treatment is instituted. These complications include arterial and venous thrombosis and stenosis; arterial pseudoaneurysm; biliary leakage, stricture, and obstruction; liver ischemia, infarction, and abscess; fluid collections and hematomas; lymphoproliferative disorders; recurrent tumors; hepatitis C virus infection; and splenic infarction. Since the clinical presentation of posttransplantation complications is frequently nonspecific and varies widely, imaging studies are critical for early diagnosis. Helical computed tomography (CT) is a valuable complement to ultrasonography (US) in the postoperative period and is a safe, accurate, and noninvasive method of demonstrating hepatic vessels (hepatic artery, portal vein, hepatic veins, and inferior vena cava) and evaluating nonvascular complications (in the hepatic parenchyma and bile duct abnormalities) and extrahepatic tissues. Knowledge and early recognition of these complications is essential for graft salvage, and CT can provide valuable information, particularly for patients with indeterminate US results or in whom US examination is difficult.
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PMID:Complications of orthotopic liver transplantation: spectrum of findings with helical CT. 1155 18

Liver transplantation is the only therapeutic option for patients with end-stage liver disease. Nitric oxide, a free radical produced from L-arginine, a potent vasodilator, also inhibits platelet adhesion and aggregation, reduces adhesion of leukocytes to the endothelium and suppresses proliferation of vascular smooth muscle cells. The inducible form of the nitric oxide synthase may generate large quantities of nitric oxide, and may be induced by the action of cytokines and lipopolysaccharides. Nitric oxide can be released from the hepatic vascular endothelium, platelets and Kupffer cells as a response to ischemia-reperfusion injury and circulatory shock. We analyzed the relationships between the levels of nitric oxide, hepatic enzymes and other clinical parameters (glucose, total proteins, total bilirubin, creatinine, albumin) obtained in serum samples before liver transplantation and every 48 h till day 15 in 15 patients aged 40 +/- 13 years. Aspartate aminotransferase and alanine aminotransferase levels changed from high at the beginning, to almost normal at the end of the study, cholinesterase levels remained decreased throughout the study and nitric oxide remained high, never reaching normal values.
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PMID:Nitric oxide in liver transplantation. 1175 5

Outcome of hepatectomy procedures depends greatly on proper control of intraoperative bleeding. We detail here the different techniques for vascular clamping, discussing their different indications. Four parameters can be used to define clamping: the zone of application: separate control of arterial or glisson pedicles and portal veins (pedicles, selective hilar, suprahilar and intrahilar clamps), suprahepatic veins or vena cava; selectivity: partial or total clamp of hepatic blood supply; duration, continuous or intermittent; association measures to favor tolerance to ischemia (cooling, preservation fluid) or to limit downstream consequences (extracorporal circulation, derivation). The optimal clamp depends on the localization of the lesion and its relations with the great vessels, presence of liver disease, and the patient's general and cardiovascular status as well as the experience of the operator and the anesthesist. The goal is to use clamp as sparingly as possible, favoring selective clamps to avoid ischemia.
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PMID:[Vascular clamping in hepatic surgery]. 1207 Oct 18


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