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

---

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

Administration of a methionine and choline deficient (MCD) diet to rodents causes progressive fibrosing steatohepatitis pathologically similar to human metabolic steatohepatitis. We have previously shown that the peroxisome proliferator-activated receptor-alpha (PPARalpha) agonist, Wy-14,643, prevented the development of MCD diet-induced steatohepatitis. We have now tested whether Wy-14,643 ameliorates established steatohepatitis and fibrosis. Male C57BL6 mice were fed the MCD diet for 51 days to induce severe steatohepatitis. They were then treated with Wy-14,643 together with the MCD diet for 5 or 12 days; positive controls continued on the MCD diet for 5 or 12 days. After 5 days of Wy-14,643 treatment, alanine aminotransferase (ALT) levels were significantly decreased, steatohepatitis less severe, and hepatic lipoperoxides significantly reduced. After 12 days, hepatic triglycerides were normalized and there was near resolution of histological changes. MCD dietary feeding was associated with increased expression of vascular cell adhesion molecule (VCAM)-1, and increased numbers of activated macrophages in the liver. Treatment with Wy-14,643 reduced VCAM-1 expression and macrophage numbers. MCD diet-fed mice developed hepatic fibrosis with increased hepatic collagen alpha1(I), tissue inhibitor of metalloproteinases (TIMP)-1, TIMP-2, and matrix metalloproteinase (MMP)-13 mRNA levels. After treatment with Wy-14,643, expression of these genes was reduced in a manner that paralleled the reduction in activated hepatic stellate cells and near resolution of liver fibrosis. In conclusion, the present study shows that MCD diet-induced fibrosing steatohepatitis can be reversed by treatment with Wy-14,643. It is likely that activation of PPARalpha reverses fibrosis indirectly by reducing stimuli, such as lipid peroxides, and activation of cells responsible for promoting hepatic fibrosis.
...
PMID:Administration of the potent PPARalpha agonist, Wy-14,643, reverses nutritional fibrosis and steatohepatitis in mice. 1512 57

Obesity and type 2 diabetes are associated with nonalcoholic steatohepatitis (NASH), but an obese/diabetic animal model that mimics human NASH remains undefined. We examined the induction of steatohepatitis and liver fibrosis in obese and type 2 diabetic db/db mice in a nutritional model of NASH and determined the relationship of the expressions of osteopontin (OPN) and leptin receptors to the pathogenesis of NASH. db/db mice and the corresponding lean and nondiabetic db/m mice were fed a diet deficient in methionine and choline (MCD diet) or control diet for 4 wk. Leptin-deficient obese and diabetic ob/ob mice fed similar diets were used for comparison. MCD diet-fed db/db mice exhibited significantly greater histological inflammation and higher serum alanine aminotransferase levels than db/m and ob/ob mice. Trichrome staining showed marked pericellular fibrosis in MCD diet-fed db/db mice but no significant fibrosis in db/m or ob/ob mice. Collagen I mRNA expression was increased 10-fold in db/db mice, 4-fold in db/m mice, and was unchanged in ob/ob mice. mRNA expressions of OPN, TNF-alpha, TGF-beta, and short-form leptin receptors (Ob-Ra) were significantly increased in db/db mice compared with db/m or ob/ob mice. Parallel increases in OPN and Ob-Ra protein levels were observed in db/db mice. Cultured hepatocytes expressed only Ob-Ra, and leptin stimulated OPN mRNA and protein expression in these cells. In conclusion, our results demonstrate the development of an obese/diabetic experimental model for NASH in db/db mice and suggest an important role for Ob-Ra and OPN in the pathogenesis of NASH.
...
PMID:Obese and diabetic db/db mice develop marked liver fibrosis in a model of nonalcoholic steatohepatitis: role of short-form leptin receptors and osteopontin. 1525 62

Hepatic fibrosis involves the interplay of many factors including reactive oxygen species. Recent reports described antioxidant properties of glycosaminoglycans (GAGs). Since several findings have shown that hyaluronic acid (HYA) and chondroitin-4-sulphate (C4S) may act as antioxidant molecules, the aim of this research was to evaluate the antioxidant effects of HYA and C4S treatment in a rat model of liver fibrosis. The effect on tissue inhibitors of metalloproteinases (TIMPs) was also studied. Liver fibrosis was induced in rats by eight intraperitoneal injections of CCl4, twice a week for 6 weeks. HYA or C4S alone (25 mg/kg) or HYA and C4S in combination (12.5 + 12.5 mg/kg) were administered daily by the same route during the 6 weeks. At the end of the 6-week treatment period (24 h after the last dose of GAGs), the following parameters were evaluated: (1) serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, as index of hepatic cell disruption; (2) hepatic conjugated dienes (CD), as index of lipid peroxidation; (3) hepatic TIMPs activity and expression; (4) hepatic superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, as index of endogenous defences; (5) hepatic hydroxyproline, as index of collagen deposition. CCl4-induced liver fibrosis enhanced lipid peroxidation and TIMPs activation, increased ALT and AST, depleted antioxidants SOD and GPx, and caused collagen deposition in liver tissue. Treatment with GAGs, especially when in combination, successfully reduced ALT and AST rise, lipid peroxidation by evaluating conjugated dienes, TIMPs activation and mRNA expression, partially restored SOD and GPx activities, and limited collagen deposition in the hepatic tissue. The data obtained showed that these molecules were able to limit hepatic injury induced by chronic CCl4 intoxication and especially limited liver fibrosis. They also confirm that HYA and C4S may exert antioxidant mechanism, while reduction of TIMPs expression suggests that GAGs may influence MMPs and TIMPs imbalance in liver fibrosis.
...
PMID:The antioxidant and antifibrogenic effects of the glycosaminoglycans hyaluronic acid and chondroitin-4-sulphate in a subchronic rat model of carbon tetrachloride-induced liver fibrogenesis. 1527 69

This study found a correlation between some serum markers [AST/ALT ratio, level of matrix metalloproteinase 9 (MMP9), level of viraemia and HCV serotype] and severity of liver fibrosis in HCV-infected patients. The study included 72 human cases referred to the Early Cancer Detection Unit, for liver biopsy assessment. The severity of liver fibrosis was staged using the METAVIR scoring system into 4 stages. The level of viraemia did not differ significantly in the different stages of liver fibrosis. Also, the type of HCV had no effect on the severity of liver fibrosis. However, the transaminases ratio differed significantly in the different fibrosis stages (P < 0.01). This serum test has a relatively high sensitivity and specificity (92.6% and 94.3%, respectively) in diagnosing severe fibrosis and cirrhosis. The level of MMP9 was, however, inversely correlated with the fibrosis stages and was found to have an 88.9% sensitivity and an 88.6% specificity when diagnosing severe fibrosis and cirrhosis. Although, the sensitivity of these serum markers did not reach 100%, yet their use can reduce the number of liver biopsies when diagnosing and treating HCV-infected patients.
...
PMID:Non-histological assessment of liver fibrosis in HCV infection. 1528 65

In 10% of the patients with chronic abnormal alanine aminotransferase (ALT) levels no cause is found. The prognosis of this liver disease, the increased risk of liver fibrosis regardless of the types of histological lesions and the need for a liver biopsy are unknown. Nearly 50% of these cases are explained by non-alcoholic steatohepatitis (NASH). The aim of this study was to evaluate, in patients with accidentally detected chronically elevated ALT levels, the prevalence of fibrosis and NASH, and the clinical and biological factors associated with each entity. Retrospectively, 67 patients (mean age, 46.6 +/- 12.1 years; 45 males) were included. All patients had a liver biopsy and were hepatitis B virus, hepatitis C virus, human immunodeficiency virus seronegative without alcohol, drug, autoimmune or genetically induced liver disease, with ALT > N (the upper limit of normal). NASH was evaluated according to necroinflammatory lesions and fibrosis. Fibrosis was evaluated according to the METAVIR score. Statistical analyses were performed using Student's t test, the Mann-Whitney rank-sum test and the chi-square test. Fibrosis scores were: F0, 37.3%; F1, 32.8%; F2, 26.9%; F3, 1.5%; and F4, 1.5%. NASH was absent in 59.7% and present in 40.3%. Significant differences were observed between F < 2 and F > or = 2 fibrosis patients for aspartate aminotransferase (AST) and ALT and between patients with NASH or without for body mass index. Overall, the risk of F > or = 2 fibrosis was increased in patients with AST > N, ALT > 2N or AST > N and ALT > 2N. The prevalence of F > or = 2 fibrosis and NASH in patients with unexplained chronic abnormal ALT are 30% and 40%, respectively. Since the risk of F > or = 2 fibrosis is significantly increased in patients with AST > N and/or ALT > 2N, liver biopsy should be performed only in patients with AST > N or ALT > 2N.
...
PMID:Should a liver biopsy be done in patients with subclinical chronically elevated transaminases? 1531 12

Nonalcoholic steatohepatitis may cause severe fibrosis, cirrhosis, and hepatocellular carcinoma, but supporting evidence is based on indirect data. Few publications have examined the results of repeat liver biopsies to evaluate progression of fibrosis. The aims of this study were to assess rate of fibrosis progression in untreated patients with nonalcoholic steatohepatitis and to identify associated variables. Among 106 patients, a second liver biopsy was proposed to those who had undergone their first liver biopsy at least 3 years before. None of them had been given pharmacological therapy. Liver biopsy samples were evaluated blindly. Variables were compared between patients with (group P) and without (group NP) fibrosis progression, using a Wilcoxon rank-sum test for numerical variables and a difference of two binomial proportions for categorical ones. Twenty-two patients (median age, 45 years; age range, 20-69 years; 13 women; diabetes in 8 patients, obesity in 10 patients) underwent a second liver biopsy 4.3 years (range, 3.0-14.3 years) after the first. Fibrosis progression was found in 7 patients in group P (31.8%), no progression was found in 15 patients in group NP. There were no differences between both groups regarding age, gender, diabetes, hyperlipidemia, ALT levels, AST-to-ALT ratio levels, albumin levels, prothrombin activity, steatosis, or inflammation. Obesity was significantly more prevalent in group P (86%) than in group NP (27%; P =.01). Basal body mass index was higher in group P (median, 33.2; range, 29.1-38.2) than in group NP (median, 29.0; range, 24.0-38.1; P =.024). Time between biopsies was not different between groups. In conclusion, progression of liver fibrosis was found in a third of nonalcoholic steatohepatitis patients 4.3 years after the first liver biopsy, and obesity and body mass index were the only associated factors with such progression.
...
PMID:Natural history of nonalcoholic steatohepatitis: a longitudinal study of repeat liver biopsies. 1538 71

Although cardiac complications remain the main causes of death in thalassemic patients, right heart dysfunction has been little studied and the mechanism is still unclear. Echocardiography was performed in 39 patients with beta-thalassemia major and 35 aged-matched controls. The gender, age, heart rate, blood pressure, left ventricular ejection fraction (LVEF), acceleration time (AcT) of right ventricular outflow and right ventricular ejection time (RVET), AcT/RVET, and the presence of tricuspid regurgitation (TR) were compared between the two groups. We also compared the gender, age, age at first blood transfusion, serum ferritin level, alanine aminotransferase (ALT), the presence of antibodies to hepatitis C virus, liver fibrosis, splenectomy, platelet counts, diabetes mellitus, arrhythmia, cardiomegaly, LVEF, AcT, RVET, AcT/RVET, and signal intensity ratio (SIR) of myocardial magnetic resonance imaging (MRI) between thalassemic patients with and without TR. The incidence of TR in thalassemic patients was significantly higher than that in the control group (30.8 vs 11.4%, p=0.03). The incidences of splenectomy (p=0.03), platelet counts (p=0.01), and SIR of myocardial MRI (p=0.03) in thalassemic patients with TR were significantly higher than in those without TR. The AcT was shorter and the AcT/RVET ratio was smaller, suggesting higher pulmonary pressure in the thalassemic patients with TR. Occurrence of TR in patients with beta-thalassemia major may be a consequence of cardiac iron deposit, thrombocytosis, splenectomy, or pulmonary hypertension.
...
PMID:Tricuspid regurgitation in patients with beta-thalassemia major. 1544 31

The hepatitis C virus is a leading cause of chronic liver disease, cirrhosis and hepatocellular carcinoma in western countries. Chronic hepatitis C is highly heterogeneous and many patients present with a mild form of liver disease. Population-based studies have indeed demonstrated that around 50% of hepatitis C virus carriers have persistently normal ALT and two-third have mild histological liver lesions. Studies on the natural history of initially mild chronic disease indicate that the short-term outcome is always benign. However, progression of liver fibrosis can be observed at long-term (>5-7 years) follow-up, particularly in those cases who have elevated and/or fluctuating transaminase levels. Observational prospective studies and outcome modelling projections indicate that the risk of liver disease progression towards severe fibrosis/cirrhosis is minimal at 10-15 years in hepatitis C virus carriers with persistently normal ALT, around 5-10% in patients with elevated ALT and F0 (no fibrosis) in the initial biopsy but >30-40% in chronic carriers with elevated ALT and F1 (portal fibrosis) in the initial biopsy. Cofactors like age at infection, alcohol, coinfections and liver steatosis accelerate disease progression. On the basis of these findings, patients with initially mild chronic hepatitis C and elevated ALT should be proposed for antiviral therapy in the absence of contraindications.
...
PMID:Natural history of initially mild chronic hepatitis C. 1550 61

Forty-eight rats with biliary obstruction induced by double ligation and section of the common bile duct were randomly and blindly assigned to receive subcutaneous injection of either conventional heparin sodium (1000IU kg(-1)), three already marketed low molecular weight heparin (LMWH) preparations: nadroparin (1000 anti-Xa IU kg(-1)), tinzaparin (1000 anti-Xa IU kg(-1)), enoxaparin (180 anti-Xa IU kg(-1)) or saline. Drugs were administered once a day, starting 7 days after surgery and continued for 3 weeks. At the end of the treatment period, rats were killed and analyzed for blood biochemistry and liver pathology. Liver fibrosis was assessed by image analysis. Data indicated that treatment with nadroparin decreased plasma total bilirubin, serum alkaline phosphatase (ALP) and gamma glutamyltransferase (GGT) levels by 80.3, 70.7 and 42%, compared with bile duct ligated (BDL) control values. The reduction in plasma total protein observed in BDL controls was prevented by nadroparin. Enoxaparin-treated rats showed significant reduction in plasma total bilirubin and alanine aminotransferase levels by 32.5 and 38.4% versus BDL controls. Liver necrosis evaluated histologically was significantly reduced in the nadroparin- and enoxaparin-treated rats. Morphometric analysis showed significant reduction in fibrosis on nadroparin and enoxaparin treatment: area of fibrosis: 1.66 +/- 0.17% and 14.03 +/- 1.1% versus 18.94 +/- 2.4% (P<0.05); nadroparin and enoxaparin versus BDL control. By contrast, neither conventional heparin nor tinzaparin prevented the bile duct ligation-induced liver damage as indicated by increased plasma aminotransferases, ALP and GGT concentrations and the histological evidence of necrosis. Total serum bilirubin was increased by 27.5% in rats treated with conventional heparin, while ALP and GGT levels were 38.6 and 31.4% higher after tinzaparin treatment versus BDL controls. Significant increase in the area of fibrosis was observed after tinzaparin treatment compared to BDL control group. Results suggest a beneficial effect for nadroparin and enoxaparin in the therapy of patients with obstructive jaundice or cholestatic liver disorders. The present data from bile duct ligated rats suggest an antifibrotic effect for nadroparin and enoxaparin.
...
PMID:A study of unfractionated and low molecular weight heparins in a model of cholestatic liver injury in the rat. 1551 36

Mycelia of the edible mushroom Lentinus edodes (shiitake) were cultivated in a solid medium, and two fractions were obtained by hot-water extraction (L.E.M.) and then ethanol extraction followed by Sephadex LH-20 column chromatography (ESMe). The L.E.M. and ESMe were then examined for their hepatoprotective effect on dimethylnitrosamine-injured mice. Both fractions decreased the blood aspartate aminotransferase and alanine aminotransferase levels, partially inhibited the overaccumulation of collagen fibrils, and suppressed the overexpression of genes for alpha-smooth muscle actin and/or heat-shock protein 47 in the mice. Both fractions also inhibited the morphologic change and proliferation of isolated rat hepatic stellate cells (HSCs), which play a central role in liver fibrosis, in a dose-dependent manner and without cytotoxicity. The direct interaction between the extracts and HSCs appears to be important for the hepatoprotective activity. Polyphenols contained in both fractions are considered to be potential candidates for expressing the hepatoprotective effects. The finding of antifibrotic activity in extracts from an edible mushroom is expected to be helpful in the development of hepatoprotective agents with few side effects.
...
PMID:Hepatoprotective effect of extracts from Lentinus edodes mycelia on dimethylnitrosamine-induced liver injury. 1557 12


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---