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)

Increased serum activities of the enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) occurred in 12 out of 19 patients with idiopathic parkinsonism when they were treated with the ergot derivative lergotrile at an oral dose varying from 50 to 150 mg daily. Hepatocellular injury was confirmed by microscopic examination of liver biopsies obtained from 3 of these patients when the serum activities of ALT and AST were appreciably elevated. Light microscopy revealed features of mild acute hepatocellular injury, and electron microscopy showed proliferation of the smooth endoplasmic reticulum and apparently unique mitochondrial changes in hepatocytes. This is the first report of pathological changes in the liver associated with the therapeutic use of an ergot derivative. The presence of a potentially reactive cyanide group in the lergotrile molecule could be causally related to the observed hepatocellular injury. It is suggested that serum ALT and AST activities should be monitored carefully when the therapeutic potential of any new ergot derivative is assessed.
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PMID:Hepatocellular injury with distinctive mitochondrial changes induced by lergotrile mesylate: a dopaminergic ergot derivative. 3 55

Intravenous administration of the rare earth metal salt, praseodymium nitrate, induced hepatic damage in the rat, as assessed by morphologic examination (light and electron microscopy) and biochemical parameters (serum glutamic-pyruvic transaminase (EC 2.6.1.2) and glutamic-oxalacetic transaminase (EC 2.6.1.1) activity as well as hepatic triglyceride content). Praseodymium hepatotoxicity was only attained with lower doses (10, 20, or 40 mg/kg), whereas a larger dose (80 mg/kg) was inactive in this respect. As detected by electron microscopy, lower doses of the metal salt caused hepatocytic alterations consisting of degranulation and dilatation of rough endoplasmic reticulum, accumulation of smooth endoplasmic reticulum as well as numerous lipid droplets. No abnormalities were detected in the cell organelles following administration of a large dose of the metal salt; however, vacuoles containing markedly electron-dense material were seen in the cytoplasm of the hepatocytes and the sinusoidal Kupffer cells.
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PMID:Effect of praseodymium nitrate on hepatocytes and Kupffer cells in the rat. 19 Nov 66

The sequential pattern of lipid accumulation and associated biochemical changes were studied in two commonly used experimental models of nutritional fatty liver in rats. Female rats were maintained for 8 weeks on high fat, low protein diets containing adequate methionine and choline, and drinking water ad libitum (Diet 1), or deficient in methionine and choline and containing 20% ethanol as a substitute for drinking water (Diet 2). Histologically, there was a progressive increase in liver lipids, mainly in the periportal areas. Occasional foci of liver cell necrosis with lipogranuloma formation occurred in areas of severe fatty change. These changes appeared earlier and were more marked in rats maintained on Diet 2. Electron micrographs revealed large lipid droplets in the liver cells, which sometimes contained myelin figures. The mitochondria were enlarged, distorted and appeared as amorphous structures with disorientated cristae in rats on Diet 1, whereas they had a condensed conformation in rats maintained on Diet 2. Rough endoplasmic reticulum was fragmented and degranulated particularly in rats on Diet 1, and smooth endoplasmic reticulum showed hyperplasia and vesiculation in rats on Diet 2. There was a progressive increase in the total liver lipids and triglycerides in both the groups of rats. This fatty change was accompanied by a significant increase in hepatic 3-hydroxybutyrate, acetoacetate, malate, 2-oxoglutarate, citrate, lactate, ammonia, glutamate, alanine and aspartate, and a significant decrease in oxaloacetate, urea and glucose concentrations. The mass action ratios for alanine aminotransferase, aspartate amino transferase, and glutamate dehydrogenase, generally moved in a parallel direction. Hepatic ATP content was considerably reduced accompanied by a decrease in [ATP]/[ADP] ratios and a significant increased in [lactate]/[pyruvate] and [3-hydroxybutyrate]/[acetoacetate] ratios. There was a corresponding decrease in the [NAD+]/[NADH] ratios both in the cytoplasmic and mitochondrial compartments. These biochemical changes were particularly severe in rats maintained on Diet 1 and Diet 2 for 8 weeks. There was a very good relationship between impaired mitochondrial and endoplasmic reticulum functions, redox and phosphorylation states, and the relevance of their changes to the fate of fatty liver cells.
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PMID:Lipid accumulation in the rat liver: a histological and biochemical study. 23

The morphological and biochemical studies were performed on the injured livers of female rats produced by chronic administration of D-galactosamine (GALN) (250 mg/kg, i.p.) for 7 months. Light microscopically, cirrhotic changes were observed in most of the animals characterized by the proliferation of the connective tissues from portal triads into hepatic lobules. The electron microscopic study demonstrated mitochondrial proliferation and irregularities with crenated membranes, focal hypertrophy of the smooth endoplasmic reticulum, decrease of the rough endoplasmic reticulum with partial detouchment of ribosomes, slight loss of compactness of nucleoli and no remarkable accumulation of lipid droplets in the cytoplasm. The proliferation of collagen fibers was observed around the hepatocytes and acid mucopolysaccharides were seen in the space of Disse and partly in the sinusoids histochemically using electron microscope. Biochemically chronic GALN administration, which increased hepatic weight significantly, resulted in a significant decrease in microsomal protein concentration, whereas cytochrome P450 content significantly increased. There was no change in phospholipid contents. After GALN, plasma albumin concentration was significantly decreased and the value of zinc turbidity test was increased. However, there was no change in plasma GPT level and total cholesterol concentration.
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PMID:D-galactosamine induced hepatic cirrhosis: its ultrastructural and biochemical studies in rat. 65 50

In the present study an ultrastructural morphometric analysis of the rat liver 1, 3 and 7 days after bile duct ligation was performed. Corresponding biochemical investigations included the determination of the cytochrom P 450 contents in the microsomal fraction. In the serum of the rats the activities of GOT and GPT were determined. The quantitative results have shown that the decreased P 450 contents of the microsomal fraction coincided with a considerable increasement of the surface of the smooth endoplasmic reticulum. The smooth endoplasmic reticulum was significantly increased from 1.83 m2/cm3 hepatocytes to 3.49 m2/cm3 hepatocytes after 3 days and remained on this level after 7 days. These results may be considered as quantitative evidence for the term hyperplastic, hypoactive endoplasmic reticulum. - As a second important result our quantitative investigations have shown that the increasement of GLDH activity in the serum especially 1 day after ligation of the bile duct coincided with a signficantly increased mitochondrial volume at this time.
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PMID:[Combined ultrastructural morphometric and biochemical investigations on the rat liver after ligation of the bile duct (author's transl)]. 100 28

The findings in our clinical study was consistent with those reported by others that a temporary elevation of serum alanine aminotransferase activity is associated with epidemic hemorrhagic fever (EHF). However, the pathogenesis of the concomitant changes in liver function tests is still not clear. To clarify whether EHF virus is cytopathic or not for the liver, percutaneous liver biopsy was done in 19 patients with EHF within 3-12 days after the onset of symptoms. These liver biopsy specimens were examined with immunofluorescence assay and cell cultural technique, showing the presence of active viral replication in liver cells. Electron microscopy observation of the infected liver cells showed that ultrastructural distortions was accompanied by the existence of inclusion bodies of EHF virus in vacuoles of rough endoplasmic reticulum, endotheliocyte and microvilli. These findings strongly suggest that EHF virus may play a causative role in liver injury in patients suffering from EHF and hepatic microcirculation disturbance may be involved in the pathogenesis of EHF-related liver dysfunction as well.
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PMID:[A study on virus localization and microcirculation in the liver in patients with epidemic hemorrhagic fever]. 135 13

Individual serum bile acids (SBA) are emerging as potentially useful early indicators of liver injury. This study was undertaken to compare the usefulness of individual SBA with the routinely used assays for detecting the effects of the hepatotoxicants carbon tetrachloride (CCl4) and chloroform (CHCl3). Serum samples were assayed for liver injury by determination of alanine aminotransferase (ALT), aspartate amino-transferase (AST), alkaline phosphatase (ALP), bilirubin and total bile acid (by enzymatic kit). These results were compared with levels of individual SBA measured by high performance liquid chromatography (HPLC). Liver samples from CCl4-treated rats were taken for light and electron microscopic examination. The highest dose for each chemical caused increases in serum ALT and AST but not ALP. Chloroform at the highest dose increased bilirubin. Total SBA levels as assayed by the kit were elevated in response to CCl4 and CHCl3 at doses below which serum enzymes and bilirubin were increased. Some individual SBA were increased at a still lower dose for each of these two chlorinated solvents. At the lowest dose of CCl4 tested no consistent light microscopic or ultrastructural changes were found. At all the higher doses periacinar cells displayed typical accumulation of lipid droplets and degranulation and dilation of rough endoplasmic reticulum. The extent of the ultrastructural changes were dose-dependent. Thus individual SBA assayed by HPLC may be considered as a very sensitive indicator of liver injury induced by the classical hepatotoxicants carbon tetrachloride and chloroform.
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PMID:Individual serum bile acids as early indicators of carbon tetrachloride- and chloroform-induced liver injury. 145 31

We studied the histological and ultrastructural changes in the liver and alterations in the liver test results before, during, and after treatment with human interferon-beta from five patients with hepatitis B e antigen-positive chronic active hepatitis. A daily dose of 3 x 10(6) to 6 x 10(6) units of interferon-beta was given intravenously for four weeks. The total index of periportal and portal inflammation, intralobular degeneration, and focal necrosis before treatment was decreased significantly six months after treatment (P less than 0.05). Ultrastructurally, the structure of endoplasmic reticulum was irregularly shaped or fragmentally decreased during treatment, but these disappeared six or 12 months after treatment. Glycogen particles diminished greatly during treatment. The alanine aminotransferase concentrations in these patients increased during treatment. Serum albumin and cholinesterase levels decreased significantly at the fourth week of treatment (P less than 0.01) and at the third day (P less than 0.01) to the second week (P less than 0.05) of treatment, respectively. These results suggest that interferon-beta injures endoplasmic reticulum and glycogen areas and damages the cholinesterase activity in the early stage of treatment and protein synthesis in patients with hepatitis B e antigen-positive chronic active hepatitis.
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PMID:Changes in ultrastructure of hepatocytes and liver test results before, during, and after treatment with interferon-beta in patients with HB(e)Ag-positive chronic active hepatitis. 149 52

A case of apolipoprotein B-related disorder is reported in which liver fibrosis developed without long term administration of medium chain triglycerides, previously incriminated in the pathogenesis of this lesion. The patient was a young woman in whom the diagnosis of familial homozygous hypobetalipoproteinaemia was made at the age of 21. A first liver specimen taken at diagnosis revealed steatosis, hypertrophic Golgi apparatus and proliferating smooth endoplasmic reticulum. The patient was treated with vitamin A and E supplementation only. Two years later, a second liver biopsy, carried out because of increased serum alanine aminotransferase concentrations, showed fibrosis, mild cytolysis and marked mitochondrial alterations. Hepatic level of vitamin A was increased. This finding supports the hypothesis that liver disease observed in our patient might be an adverse effect of vitamin supplementation. Our observation underlines the importance of including liver function tests in the follow up of patients with apolipoprotein B-related disorders.
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PMID:Liver fibrosis in a patient with familial homozygous hypobetalipoproteinaemia: possible role of vitamin supplementation. 156 67

Asparagine-linked glycosylation is initiated by the synthesis of N-acetylglucosaminylpyrophosphoryl dolichol (GlcNAc-P-P-dolichol), which is extended by a series of glycosyltransferases to yield Glc3Man9GlcNAc2-P-P-dolichol (where Glc is glucose and Man is mannose). The oligosaccharide unit is then transferred en bloc to asparagine residues of nascent polypeptides in the lumen of the rough endoplasmic reticulum. The question here is whether GlcNAc-P-P-dolichol biosynthesis is a fixed process unaffected by cellular events, or a regulated reaction responsive to cellular requirements for glycoprotein biosynthesis. Several lines of evidence indicate that the latter is the case and that GlcNAc-P-P-dolichol biosynthesis may be subject to multiple forms of regulation. Recent information about the N-acetylglucosamine-1-P transferase (GPT) responsible for this reaction and the cloning of cDNA candidates for this enzyme have provided further insight into these mechanisms. This review will examine current hypotheses dealing with GPT and its role in the committed step of asparagine-linked glycosylation.
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PMID:Biosynthesis of N-acetylglucosamine-P-P-dolichol, the committed step of asparagine-linked oligosaccharide assembly. 166 6


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