AIM: To investigate the relationship between serum paraoxonase (PON1), AST, ALT, GGT, and arylesterase (AE) activity alterations and the degree of liver damage in patients with chronic hepatitis.METHODS: We studied 34...AIM: To investigate the relationship between serum paraoxonase (PON1), AST, ALT, GGT, and arylesterase (AE) activity alterations and the degree of liver damage in patients with chronic hepatitis.METHODS: We studied 34 chronic hepatitis patients and 32 control subjects, aged between 35 and 65 years,in the Department of Infection and Clinical Microbiology at the Firat University School of Medicine. Blood samples were collected from subjects between 8:00 and 10:00 a.m. following a 12-h fast. Baseline and salt-stimulated PON1 activities were measured by the hydrolysis of paraoxon. Phenyl acetate was used as the substrate and formed phenol was measured spectrophotometrically at 270 nm after the addition of a 10-fold diluted serum sample in AE activity measurements.RESULTS: The results of this investigation revealed that the levels of AE activity decreased from 132±52 to 94±36 (29%), baseline PON1 activity from 452±112 to 164±67 (64%), salt-stimulated PON1 activity from 746±394 to 294±220 (61%), HDL from 58.4±5.1 to 47.2±5.6(20%), triglyceride from 133±51.2 to 86±34.0 (35%),while a slight increase in the level of LDL (from 163±54.1 to 177.3±56.0; 9%) and significant increases in the levels of AST (from 29±9.3 to 98±44), ALP (from 57.2±13.1 to 91±38.1), ALT (from 27.9±3.32 to 89±19.1), GGT (from 24.3±2.10 to 94±48.2), total bilirubin (from 0.74±0.02 to 1.36±0.06; 84%) and direct bilirubin (from 0.18±0.01 to 0.42±0.04; 133%) were detected.However, the levels of albumin, total protein, cholesterol,and uric acid were almost the same in chronic hepatitis and the control subjects.CONCLUSION: Low PON1 and AE activity may contribute to the increased liver dysfunction in chronic hepatitis patients by reducing the ability of HDL to retard LDL oxidation and might be clinically useful for monitoring the disease of chronic hepatitis.展开更多
AIMTo investigate the oxidative stress status of the aqueous humor and serum of patients with pseudoexfoliation (PEX) syndrome and pseudoexfoliative glaucoma (PEG) and to measure paraoxonase (PON) and arylesterase (AR...AIMTo investigate the oxidative stress status of the aqueous humor and serum of patients with pseudoexfoliation (PEX) syndrome and pseudoexfoliative glaucoma (PEG) and to measure paraoxonase (PON) and arylesterase (ARE) levels.METHODSA total of 78 patients were enrolled in the study, with 26 patients in each separate group. The patients were divided into three groups: the first group entailed PEX syndrome patients, while the second group consisted of patients with PEG and the third group involved patients with no additional systemic diseases, other than the diagnosis of cataract as control. Total oxidative stress (TOS), total antioxidant capacity (TAC), PON, and ARE levels in aqueous humor and serum were measured.RESULTSTAC, PON and arylesterase levels in aqueous humor and serum of the PEX syndrome and PEG patients were significantly decreased compared with control group (P<0.05). TOS values were higher in patients with PEX syndrome and PEG than controls (P<0.05). TAC, PON and ARE levels of aqueous humor did not differ significantly between the PEX syndrome and PEG groupsCONCLUSIONThese findings are potentially of significance and add to the growing body of evidence for oxidative stress in PEX syndrome and PEG. Decreased antioxidant defense and increased oxidative stress system may play an important role in the pathogenesis of PEX syndrome and PEG.展开更多
Objective To investigate the possible mechanism by which curcumio protects stomach during the acute chronic phase of gastric ulcer disease. Methods The rats were divided into four groups and fasted for 2 days with fle...Objective To investigate the possible mechanism by which curcumio protects stomach during the acute chronic phase of gastric ulcer disease. Methods The rats were divided into four groups and fasted for 2 days with flee access to water. On the third day, the animals were fasted for a further 24 h with no access to water followed by surgery. Rats received different doses of curcumin （20, 40, and 80 mg/kg） or vehicle by oral gavage. Nineteen hours after ulcer induction, the rats were killed by decapitation. Stomach was opened along the greater curvature and ulcerative lesions were counted. Total juice acidity, neutrophils activity, mitochondrial activity, total antioxidants, paraoxonase （PON 1）/arylesterase and total peroxides were evaluated. DNA fragmentation （%） and pro-inflammatory cytokine IL-6 level were measured. The level of different gastro-cytoprotective effectors including total antioxidants and paraoxonase （PON 1）/arylesterase activities was measured. Results The anti-ulcer activity of curcumin was displayed by attenuating the different ulcerative effectors including gastric acid hyper-secretion, total peroxides, myeloperoxiase （MPO） activity, IL-6 and apoptotic incidence. Conclusion Cureumin appears to have a propitious protective effect against gastric ulcer development.展开更多
Objective: To investigate the reliability for fast estimation of Michaelis-Menten constant (Km) with calibrated specific activity at only two medium concentrations of substrate by both simulation and experimentation w...Objective: To investigate the reliability for fast estimation of Michaelis-Menten constant (Km) with calibrated specific activity at only two medium concentrations of substrate by both simulation and experimentation with arylesterase (ArE)as model. Methods: Initial rates were simulated by randomly inserting uniform absolute error, and the experimental initial rates of ArE were determined by measuring the increaser of product absorbance. Calibrated specific activities at two substrate concentrations were obtained by regression analysis, and Km was calculated according to Michaelis-Menten equation. Results: By simulation with calibrated specific activities at two medium substrate concentrations, Km could be calculated according to Michaelis-Menten equation with reasonable precision and accuracy. By experimentation with substrates of 2-naphthyl acetate, phenyl acetate, and p-nitrophenyl acetate, there were no differences between the mean and SD of Km of ArE for either substrate by this linear kinetic method and the Lineweaver-Burk plot. Conclusion: This linear kinetic method was reliable for fast estimation of the Km of some specified enzyme on its substrate of lower solubility or lower sensitivity for quantification by common methods.展开更多
文摘AIM: To investigate the relationship between serum paraoxonase (PON1), AST, ALT, GGT, and arylesterase (AE) activity alterations and the degree of liver damage in patients with chronic hepatitis.METHODS: We studied 34 chronic hepatitis patients and 32 control subjects, aged between 35 and 65 years,in the Department of Infection and Clinical Microbiology at the Firat University School of Medicine. Blood samples were collected from subjects between 8:00 and 10:00 a.m. following a 12-h fast. Baseline and salt-stimulated PON1 activities were measured by the hydrolysis of paraoxon. Phenyl acetate was used as the substrate and formed phenol was measured spectrophotometrically at 270 nm after the addition of a 10-fold diluted serum sample in AE activity measurements.RESULTS: The results of this investigation revealed that the levels of AE activity decreased from 132±52 to 94±36 (29%), baseline PON1 activity from 452±112 to 164±67 (64%), salt-stimulated PON1 activity from 746±394 to 294±220 (61%), HDL from 58.4±5.1 to 47.2±5.6(20%), triglyceride from 133±51.2 to 86±34.0 (35%),while a slight increase in the level of LDL (from 163±54.1 to 177.3±56.0; 9%) and significant increases in the levels of AST (from 29±9.3 to 98±44), ALP (from 57.2±13.1 to 91±38.1), ALT (from 27.9±3.32 to 89±19.1), GGT (from 24.3±2.10 to 94±48.2), total bilirubin (from 0.74±0.02 to 1.36±0.06; 84%) and direct bilirubin (from 0.18±0.01 to 0.42±0.04; 133%) were detected.However, the levels of albumin, total protein, cholesterol,and uric acid were almost the same in chronic hepatitis and the control subjects.CONCLUSION: Low PON1 and AE activity may contribute to the increased liver dysfunction in chronic hepatitis patients by reducing the ability of HDL to retard LDL oxidation and might be clinically useful for monitoring the disease of chronic hepatitis.
文摘AIMTo investigate the oxidative stress status of the aqueous humor and serum of patients with pseudoexfoliation (PEX) syndrome and pseudoexfoliative glaucoma (PEG) and to measure paraoxonase (PON) and arylesterase (ARE) levels.METHODSA total of 78 patients were enrolled in the study, with 26 patients in each separate group. The patients were divided into three groups: the first group entailed PEX syndrome patients, while the second group consisted of patients with PEG and the third group involved patients with no additional systemic diseases, other than the diagnosis of cataract as control. Total oxidative stress (TOS), total antioxidant capacity (TAC), PON, and ARE levels in aqueous humor and serum were measured.RESULTSTAC, PON and arylesterase levels in aqueous humor and serum of the PEX syndrome and PEG patients were significantly decreased compared with control group (P<0.05). TOS values were higher in patients with PEX syndrome and PEG than controls (P<0.05). TAC, PON and ARE levels of aqueous humor did not differ significantly between the PEX syndrome and PEG groupsCONCLUSIONThese findings are potentially of significance and add to the growing body of evidence for oxidative stress in PEX syndrome and PEG. Decreased antioxidant defense and increased oxidative stress system may play an important role in the pathogenesis of PEX syndrome and PEG.
文摘Objective To investigate the possible mechanism by which curcumio protects stomach during the acute chronic phase of gastric ulcer disease. Methods The rats were divided into four groups and fasted for 2 days with flee access to water. On the third day, the animals were fasted for a further 24 h with no access to water followed by surgery. Rats received different doses of curcumin （20, 40, and 80 mg/kg） or vehicle by oral gavage. Nineteen hours after ulcer induction, the rats were killed by decapitation. Stomach was opened along the greater curvature and ulcerative lesions were counted. Total juice acidity, neutrophils activity, mitochondrial activity, total antioxidants, paraoxonase （PON 1）/arylesterase and total peroxides were evaluated. DNA fragmentation （%） and pro-inflammatory cytokine IL-6 level were measured. The level of different gastro-cytoprotective effectors including total antioxidants and paraoxonase （PON 1）/arylesterase activities was measured. Results The anti-ulcer activity of curcumin was displayed by attenuating the different ulcerative effectors including gastric acid hyper-secretion, total peroxides, myeloperoxiase （MPO） activity, IL-6 and apoptotic incidence. Conclusion Cureumin appears to have a propitious protective effect against gastric ulcer development.
文摘Objective: To investigate the reliability for fast estimation of Michaelis-Menten constant (Km) with calibrated specific activity at only two medium concentrations of substrate by both simulation and experimentation with arylesterase (ArE)as model. Methods: Initial rates were simulated by randomly inserting uniform absolute error, and the experimental initial rates of ArE were determined by measuring the increaser of product absorbance. Calibrated specific activities at two substrate concentrations were obtained by regression analysis, and Km was calculated according to Michaelis-Menten equation. Results: By simulation with calibrated specific activities at two medium substrate concentrations, Km could be calculated according to Michaelis-Menten equation with reasonable precision and accuracy. By experimentation with substrates of 2-naphthyl acetate, phenyl acetate, and p-nitrophenyl acetate, there were no differences between the mean and SD of Km of ArE for either substrate by this linear kinetic method and the Lineweaver-Burk plot. Conclusion: This linear kinetic method was reliable for fast estimation of the Km of some specified enzyme on its substrate of lower solubility or lower sensitivity for quantification by common methods.
基金supported by grants from the Fundamental Research Funds for the Central Universities(CQDXWL-2012-014,CDJZR10220004)The National Natural Science Foundation of China(20805060)~~
