Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of interferon therapy on liver histologic findings were assessed in a randomized controlled trial consisting of 80 patients with chronic non-A,non-B hepatitis. Twenty-eight patients received 1 million units of recombinant interferon alpha-2b; 25 patients received 3 million units, subcutaneously, three times a week for 24 weeks; and 21 patients were observed as untreated controls; all of them underwent liver biopsy within 6 months from the beginning of the study and on the last day of therapy. Six patients were withdrawn from the study because of inadequate liver biopsy specimens. Alanine aminotransferase levels were determined before, during, and after therapy. For each biopsy, a semiquantitative score of histologic features, the histologic activity index, and the overall histologic assessment were performed. Ninety-five percent of patients tested positive for hepatitis C virus antibody. Portal inflammation, piecemeal and spotty necrosis, and bile duct proliferation were significantly decreased in patients with normalized alanine aminotransferase. The effectiveness of therapy was dose dependent: piecemeal and spotty necrosis and the histologic activity index showed a significant decrease only in 3-million-unit-treated patients. Hepatocellular degeneration and fibrosis did not change significantly after treatment.
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PMID:Histologic changes in liver biopsy specimens produced by recombinant interferon alpha-2b therapy for chronic non-A,non-B viral hepatitis. A randomized controlled trial. 141 21

Three tamarins (Saguinus labiatus), two of which had previously been infected with hepatitis A virus and parenteral non-A, non-B hepatitis, were inoculated intravenously with the agent of GB hepatitis. All three animals developed alanine aminotransferase abnormalities 2 weeks after inoculation. Peak alanine aminotransferase levels were recorded 4 weeks postinoculation. These declined thereafter but continued to fluctuate at abnormal levels for 32 weeks. Liver biopsies showed liver cell swelling and inflammation with focal necrosis. Portal tracts and areas around central veins were heavily infiltrated with mononuclear cells. A fourth animal (no previous exposure to hepatitis viruses) inoculated with GB was killed on Day 15 postinoculation. Serum and extracts of liver and feces from this day were used as inocula for three other animals. Only the serum and liver extract transmitted GB hepatitis. The fecal specimen did not transmit and a fecal extract taken at a later date from another animal was also noninfectious. GB hepatitis virus is distinct from the viruses causing Type A and blood-borne non-A, non-B-hepatitis. Although the virus is present in serum and has previously been transmitted per os, it is not shed in feces.
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PMID:Studies of GB hepatitis agent in tamarins. 253 47

We studied portal hemodynamic changes by using duplex Doppler in 10 pigs with hepatic artery embolization (HAE) and hepatic artery ligation (HAL) and in 5 with HAL only. Serum concentration of alkaline phosphatase, ALT, direct and indirect bilirubin were determined simultaneously. Hepatic angiography and hepatic vascular cast were performed in the 5 pigs, and pathological examination in others. Portal venous velocity (PVV) and portal blood flow (PBF) increased after HAE, ALP, ALT, direct indirect bilirubin slightly elevated (P > 0.05) in the two groups after operation and most of them decreased subsequently within 7 days. Linear regression of PBF with ALP, ALT, direct and indirect bilirubin occurred in the experimental group. Liver necrosis was seen in all pigs of the experimental group and only one in the control group. Angiography and vascular cast showed that hepatic artery collaterals occurred at the portal hilus in the two groups and were more rich in the control group. Extrahepatic and intrahepatic arterial collaterals were seen from 1 to 3 weeks after HAE. The estimation of PVV and PBF by duplex Doppler may reflect the development of collaterals indirectly and is helpful in assessing the effect of HAE.
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PMID:[Experimental study of portal hemodynamic changes after hepatic artery embolization]. 825 4

1. Isolated perfused cirrhotic rat livers were used to study the effects of an increase in portal perfusion pressure and portal flow on the microcirculation and viability of the hepatocytes. Cirrhosis was induced by CCl4, and Krebs-Ringer bicarbonate buffer solution was used as the perfusate. Portal perfusion pressures were increased incrementally between 25 and 45 cm H2O. The viability of the livers was assessed and histological studies were performed under light and electron microscopy. 2. An increase in portal perfusion pressure induced an increase in hepatic flow in all the experiments (P < 0.05). Hepatic flow was 2.52 ml min-1g-1 of liver (SD 0.67; n = 5) at basal pressure compared with 4.19 ml min-1g-1 of liver (SD 0.93; n = 5) and 5.91 ml min-1g-1 of liver (SD 0.63; n = 5) when pressures were raised to 25 and 45 cmH2O, respectively. Portal perfusion pressure and hepatic flow were correlated (r = 0.908; P < 0.001; n = 30). 3. Production of the enzyme alanine aminotransferase (EC 2.6.1.2) increased significantly from 5.69i.u. ml-1min g-1 of liver (SD 3.62; n = 5) to 23.53i.u. ml-1min g-1 of liver (SD 16.7; n = 5) when the perfusion pressure was raised from baseline to 30 cmH2O. In all the cases the porto-caval gradient of enzyme production was within the normal range. No correlation existed between the release of enzyme and portal perfusion pressures.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Augmented portal flow in the isolated perfused cirrhotic rat liver: a haemodynamic and morphological study. 838 84

The changes of hepatic hemodynamics and hepatic oxygen metabolism after portal arterialization (APS) were studied. Beagle dogs were used for the experiments. Dogs were grouped as follows: group I (n = 6) had 2 days of APS, group II (n = 6) had 1 week of APS, group III (n = 6) had 4 weeks of APS. Portal arterialization performed by the anastomosis between the end of the hepatic artery and the hepatic portion of the side of the portal vein following ligation of the hepatic artery, the gastro-duodenal artery and the right gastric artery. It has been confirmed that arterio-portal shunt flow of this experimental model is the optimal arterio-portal shunt flow by the basic study. In all groups, total hepatic blood flow increased more than about 120% of its initial value, and was controlled after 2 days, 1, or 4 weeks, there were no significant variation with the first postoperative determination. Portal vein pressure, portal vein resistance did not present significant changes compared with the preoperative determination. Hepatic oxygen delivery, hepatic oxygen consumption and hepatic oxygen extraction ratio presented no significant changes compared with the preoperative determination in all groups. Concentration levels of serum GOT, GPT, total bile acid elevated significantly in group I, but in group II and III, there was no significant difference compared with the preoperative level. AKBR and mGOT were not significantly different compared with the preoperative level in all groups. Histologically, the liver structure, common bile duct and portal vein showed no ischemic change compared with the control biopsy in all groups. In conclusion, this study showed portal arterialization under the optimal arterio-portal shunt flow has beneficial effects on liver under hepatic arterial obstruction for 4 weeks.
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PMID:[Experimental studies concerning about the effects of the portal arterialization 4 weeks after ligation of hepatic artery under the optimal arterio-portal shunt blood flow]. 936 66

The histopathology and clinical picture of hepatocellular carcinoma (HCC) varies between individual patients and regions. These variations are perhaps due to differences in the genetic alterations that precede hepatocarcinogenesis. In this study, the clinicopathological features of HCC were compared between southern African blacks and Japanese, indicating large differences in the frequency of underlying cirrhosis, grade of cancer cell differentiation and clinical course. Intra-abdominal bleeding and febrile, rapidly progressive HCC are more common among blacks. Such a difference is accounted for, in part, by frequent encapsulation of the tumour which is well differentiated, and grows slowly in an expanding fashion in Japan. Encapsulated HCC was not seen among the black patients studied. Other distinct clinicopathological types discussed in this paper include diffuse-type HCC which is usually caused by multiple portal spread occurring almost simultaneously; the clinical course is fulminant. Sclerosing carcinoma is frequently associated with hypercalcaemia in the United States, but not in Japan. Fibrolamellar carcinoma is nearly non-existent in Asia, whereas it is common among young adults in the West. Its prognosis is generally better than ordinary HCC. Hepatocellular carcinoma has a strong propensity to invade vessel and duct systems. Portal invasion does not produce distinct clinical signs although it may aggravate portal hypertension. Patients with tumour occlusion in the major portal vein may give rise to ischaemic hepatitis when blood pressure drops suddenly in the preterminal stage. Liver parenchyma develops submassive necrosis and clinically there is an acute rise in alanine aminotransferase (ALT). Invasion into a major hepatic vein and the inferior vena cava also occurs, but less frequently compared with portal invasion. The patient can live even with a tumour thrombus in the atrium crossing the tricuspid valves. Intraductal invasion causes acute jaundice as well as an occasional haemobilia with pain. We recently found that a distinct pathological type called 'extrahepatic growth' or 'pedunculated HCC' develops as a result of fusion of right-sided adrenal metastasis of HCC and the liver, perhaps through the 'adreno-hepatic fusion' which is rather common in cirrhotic livers.
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PMID:Hepatocellular carcinoma: clinicopathological aspects. 940 52

The role of nitric oxide (NO) on liver oxidative stress and tissue injury in rats subjected to tourniquet shock was investigated. This shock model differs from others in that injury is a consequence of remote organ damage. Liver oxidative stress becomes evident after hind limb reperfusion, as evidenced by the loss of total tissue thiols; by increases in tissue oxidized glutathione (GSSG), lipid peroxidation (LPO), plasma aminotransferases (alanine aminotransferase (ALT) and (aspartate aminotransferase (AST)), and plasma nitrites; and by a 36% loss in total superoxide dismutase (SOD) activity. Portal blood flow is reduced by 54.1% after 2 h of hind limb reperfusion. Inhibition of NO synthesis with Nomega-nitro-L-arginine methyl ester or L-arginine methyl ester increased mean arterial blood pressure; further reduced portal blood flow; and aggravated liver injury as assessed by further loss in total thiols, increased LPO and GSSG content, and further increases in plasma ALT and AST. Total plasma nitrites were lower than in control animals, and total tissue SOD activity decreased by more than 80%. Treatment with the NO donor sodium nitroprusside reverted the decrease in portal blood flow and also reverted tissue thiol loss, LPO, and GSSG increases, as well as the loss of ALT and AST to plasma and of SOD activity to levels comparable to untreated control shock animals. As expected, plasma nitrites were greater than in tourniquet control animals. These data support the hypothesis that endogenous NO formation protects the rat liver from the consequences of oxidative stress elicited by hind limb reperfusion in rats subjected to tourniquet shock.
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PMID:Inhibition of nitric oxide synthesis aggravates hepatic oxidative stress and enhances superoxide dismutase inactivation in rats subjected to tourniquet shock. 961 80

The purpose of this study was to prove the hypothesis that ET-1 production is increased in the splanchnic-hepato circulation during cardiopulmonary bypass (CPB) with or without hypothermia and this greatly affects hepatocellular function after surgery. Twelve Japanese white rabbits were used. In group I (n = 6), the rectal temperature was kept at 37.0 degrees C during CPB (90 min). In group II (n = 6), the rectal temperature was lowered to 26 degrees C during the first 30 minutes and then increased to 37 degrees C for the following 60 minutes. In group I, surface liver tissue blood flow (LBF) remained stable during CPB. While, in group II, LBF was significantly reduced to 66.9% of baseline values during hypothermic CPB, but it increased during the rewarming phase to 84.3% of the baseline value (p = 0.0070). At the end of CPB, portal ET-1 levels were increased in both groups, but they were significantly higher in group II (7.32 +/- 0.50 pg/ml and 9.29 +/- 0.61 pg/ml, respectively). Serum GOT, GPT, LDH and arterial ammonia levels were also higher in group II. Portal ET-1 levels had a significant positive correlation with those liver enzymes. Histopathological examination after CPB showed severe damage of the hepatic parenchyma in zone 3 associated with microvesicular fatty infiltration in group II.
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PMID:Increased portal endothelin-1 level is associated with the liver function after cardiopulmonary bypass in rabbits: influence of hypothermia on the damage. 984 52

This study was performed to determine whether ischemia/reperfusion (I/R) injury in rat liver results in alterations in endothelin receptor expression. Hepatic ischemia was produced in rats for 60 min followed by 6 or 24 h reperfusion. Portal inflow pressure was increased (7.38+/-0.60 mmHg) at 24 hours after reperfusion. Serum ALT increased significantly at both 6 and 24 h (6 h; 258.3+/-74.3, 24 h; 243.1+/-74.8 IU/L). Portal vascular response to an endothelin-B receptor agonist (IRL 1620) was significantly increased in the I/R livers compared to control and this was potentiated by L-NAME. IRL 1620 also caused LDH release from I/R livers but not controls. LDH release after IRL 1620 in I/R livers correlated with increased portal pressure response. To determine whether the altered response might be the result of altered endothelin receptor expression, livers were harvested after reperfusion and total endothelin binding sites were determined by competitive binding with ET-1. Proportion of endothelin receptor subtypes (ET(A)/ET(B)) was determined using the ET(A) antagonist BQ-610 (1 microM) and ET(B) agonist IRL-1620 (100 nM). There were no significant changes in Kd but Bmax for endothelin-1 was decreased in I/R group especially non-ischemic lobe at 24 h. ET(A) receptors were significantly decreased whereas ET(B) receptors were increased. These changes were more pronounced at 24 h after reperfusion than at 6 h. Interestingly, the changes in ET receptors was observed identically both in ischemic and non-ischemic lobes (ischemic lobe ET(A) 41.9%, ET(B) 51%; non-ischemic lobe ET(A) 38.8%, ET(B) 49.5%). These results indicate that the major functional endothelin receptor subtype upregulated in I/R is the ET(B) receptor and that this upregulation may contribute to microvascular dysregulation and hepatic injury.
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PMID:Altered endothelin receptor subtype expression in hepatic injury after ischemia/reperfusion. 1063 73

Increased gut permeability (leaky gut) and endotoxin-mediated Kupffer cell activation are proposed as the mechanisms of alcoholic liver injury. Although ethanol feeding is shown to sensitize the liver for injury induced by parental administration of lipopolysaccharide (LPS), how enteral LPS loading affects alcoholic liver injury is yet to be tested. The present study provides direct evidence for enhanced entrance to portal circulation of LPS enterally administered to the intragastric ethanol infusion model. Portal and systemic blood endotoxin levels increased to 43.0 +/- 4.1 and 6.2 +/- 4.3 pg/mL at 2 hours following enteral LPS administration (5 mg/kg) in alcohol-fed animals, while no such increases were observed in pair-fed controls. However, endotoxin levels in systemic blood of alcohol-fed rats were reduced to 0 to 1. 5 pg/mL 16 hours after LPS administration. Weekly enteral administration of LPS to the model for 9 weeks exacerbated an increase in plasma alanine transaminase (ALT) levels (227 +/- 75 vs. 140 +/- 70; P <.01), mononuclear infiltration (25 +/- 22 vs. 6.4 +/- 4.4/10 mm(2); P =.02), sinusoidal congestion, and spotty necrosis, and induced diffuse coagulative necrosis and centrilobular fibrosis in some animals. Reverse-transcription polymerase chain reaction (RT-PCR) analysis confirmed the LPS effect at the tissue level by demonstrating accentuated induction of tumor necrosis factor alpha (TNF-alpha) and Cox-2 mRNA. In conclusion, enteral LPS administration potentiates alcoholic liver necrosis, inflammation, and fibrosis despite efficient endotoxin clearance by the liver and mild systemic endotoxemia that occurs episodically following enteral LPS challenge.
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PMID:Exacerbation of alcoholic liver injury by enteral endotoxin in rats. 1105 51


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