AIM: To determine serum γ-glutamyltransferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity, and to assess their correlation with demographic and clinical findings in healthy bl...AIM: To determine serum γ-glutamyltransferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity, and to assess their correlation with demographic and clinical findings in healthy blood donors. METHODS: This cross-sectional study was performed in 934 male blood donors, aged 18 to 68 years, who consecutively attended Tehran blood transfusion service in 2006. All participants were seronegative for HBV or HCV infections, non alcohol users, and all underwent a standard interview and anthropometric tests. Clinical and biochemical parameters including AST, ALT, and GGT activities were determined. Patients taking drugs known to cause hepatic fat deposition were excluded. For AST, ALT, and GGT variables, we used 33.33 and 66.66 percentiles, so that each of them was divided into three tertiles. RESULTS: Mean AST, ALT, and GGT activities were 25.26 ± 12.58 U/L (normal range 5-35 U/L), 33.13 ± 22.98 (normal range 5-35 U/L), and 25.11 ± 18.32 (normal range 6-37 U/L), respectively. By univariate analyses, there were significant associations between increasing AST, ALT, or GGT tertiles and age, body weight, body mass index, and waist and hip circumferences (P < 0.05). By multiple linear regression analyses, ALT was found to be positively correlated with dyslipidemia (B = 6.988, P = 0.038), whereas ALT and AST were negatively correlated with age. AST, ALT, and GGT levels had positive correlation with family history of liver disease (B = 15.763, P < 0.001), (B = 32.345, P < 0.001), (B =24.415, P < 0.001), respectively.CONCLUSION: Although we did not determine the cutoffs of the upper normal limits for AST, ALT, and GGT levels, we would suggest screening asymptomatic patients with dyslipidemia and also subjects with a family history of liver disease.展开更多
A total of 69 strains of thermophilic bacteria were isolated from water, soil and sediment samples from three Indonesia's hot spring areas (Pantai cermin, Kalianda and Banyu wedang) by using Minimal Synthetic Medi...A total of 69 strains of thermophilic bacteria were isolated from water, soil and sediment samples from three Indonesia's hot spring areas (Pantai cermin, Kalianda and Banyu wedang) by using Minimal Synthetic Medium (MSM). The extreme thermophile Brevibacillus sp. PLI-1 was found to produce extracellular thermophilic alkaline protease with optimal activity at 70℃ and pH 8.0-9.0. The molecular weight of the protease was estimated to be around 56 kD by SDS-PAGE. The maximum activity of the protease was 26.54 U mL-1. The protease activity did not decrease after 30 min and still retained more than 70% of relative activity after 60 min at 70℃ and pH 8.0. The ion Mg2+ was found to promote protease activity at both low and high concentrations, whereas Cu2+ and Zn2+ could almost completely inhibit the activity. Divalent cation chelator EDTA inhibited the enzyme activity by 55.06% ± 0.27%, while the inhibition caused by PMSF, Leupeptin, Pepstain A and Benzamidine were 66.78% ± 3.25%, 52.37% ± 0.25%, 62.47% ± 2.96% and 50.99% ± 0.24%, respectively. Based on these observations, the enzyme activity was conspicuously sensitive to the serine and cysteine protease inhibitors. All these results indicated that the protease isolated from the strain PLI-1 was a thermophilic protease and had a high-temperature stability and a pH stability.展开更多
AIM: To evaluate serum alanine aminotransferase (ALT)activity in a well-characterized group of uncomplicated obese subjects and its correlation with insulin resistance,plasma adiponectin, and leptin concentrations.MET...AIM: To evaluate serum alanine aminotransferase (ALT)activity in a well-characterized group of uncomplicated obese subjects and its correlation with insulin resistance,plasma adiponectin, and leptin concentrations.METHODS: One hundred and five uncomplicatedobese subjects (87 women, 18 men, age 34.3±9.6 years,BMI 39.9±8.3 kg/m2)were studied. Serum ALT activity was evaluated. Insulin sensitivity was assessed by euglycemic hyperinsulinemic clamp (M index) and fasting insulin. Plasma leptin and adiponectin levels were also measured.RESULTS: Serum ALT concentration in the whole group of uncomplicated obese subjects was 17.73±6.33 U/L with none of the subjects presenting ALT levels greater than 43 U/L and only 9 (11%) women and 3 (19%) men showed ALT levels ＞19 and ＞30 U/L for women and men,respectively. No significant difference was detected in serum ALT levels between severe obese subjects (BMI ＞40 kg/m2) and those with BMI ＜40 kg/m2 (18.63±6.25 vs 17.26±6.02 U/L). ALT was significantly correlated with fasting insulin (r = 0.485, P = 0.02) and triglycerides (r= 0.358, P= 0.03).CONCLUSION: Serum ALT activity is practically normal in uncomplicated obese subjects, independently of their obesity degree. These findings suggest the role of obesityrelated comorbidities and not of BMI as main risk factors for elevated ALT levels in obese subjects.展开更多
AIM： To assess whether portacaval anastomosis （PCA） in rats affects the protein expression and/or activity of glutaminase in kidneys, intestines and in three brain areas of cortex, basal ganglia and cerebellum and ...AIM： To assess whether portacaval anastomosis （PCA） in rats affects the protein expression and/or activity of glutaminase in kidneys, intestines and in three brain areas of cortex, basal ganglia and cerebellum and to explain the neurological alterations found in hepatic encephalopathy （HE）. METHODS： Sixteen male Wistar rats weighing 250-350 g were grouped into sham-operation control （n=8） or portacaval shunt （n = 8）. Twenty-eight days after the procedure, the animals were sacrificed. The duodenum, kidney and brain were removed, homogenised and mitochondria were isolated. Ammonia was measured in brain and blood. Phosphate-activated glutaminase （PAG） activity was determined by measuring ammonia production following incubation for one hour at 37 ℃ with O-phthalaldehyde （OPA） and specific activity expressed in units per gram of protein （pkat/g of protein）. Protein expression was measured by immunoblotting. RESULTS： Duodenal and kidney PAG activities together with protein content were significantly higher in PCA group than in control or sham-operated rats （duodenum PAG activity was 976.95±268.87μkat/g of protein in PCA rats vs 429.19±126.92.μkat/g of protein in shamoperated rats; kidneys PAG activity was 1259.18±228.79 μkat/g protein in PCA rats vs 669.67±400.8 μkat/g of protein in controls, P〈0.05; duodenal protein content： 173% in PCA vs sham-operated rats; in kidneys the content of protein was 152% in PCA vs sham-operated rats）. PAG activity and protein expression in PCA rats were higher in cortex and basal ganglia than those in shamoperated rats （cortex： 6646.6 ±1870.4 μkat/g of protein vs 3573.8± 2037.4 μkat/g of protein in control rats, P〈 0.01; basal ganglia, PAG activity was 3657.3± 1469.6 μkat/g of protein in PCA rats vs 2271.2±384 μkat/g of protein in sham operated rats, P〈0.05; In the cerebellum, the PAG activity was 2471.6±701.4 μkat/g of protein vs 1452.9 ±567.8 μkat/g of protein in the PCA and sham rats, respectively, P〈0.05; content of protein： cerebral cortex： 162% ±40% vs 100% ± 26%, P〈 0.009; and basal ganglia： 140% ±39% vs 100% ±14%, P〈0.05; but not in cerebellum： 100% ±25% vs 100% ± 16%, P= ns）. CONCLUSION： Increased PAG activity in kidney and duodenum could contribute significantly to the hyperammonaemia in PCA rats, animal model of encephalopathy. PAG is increased in non-synaptic mitochondria from the cortex and basal ganglia and could be implicated in the pathogenesis of hepatic encephalopathy. Therefore, PAG could be a possible target for the treatment of HE or liver dysfunction.展开更多
Objective: To investigate whether fused hirudin peptide has both antithrombin and antiplatelet functions. Methods: The core region of fused hirudin was the C-terminal tail of hirudin(hirudin_ 53-64),which could bind t...Objective: To investigate whether fused hirudin peptide has both antithrombin and antiplatelet functions. Methods: The core region of fused hirudin was the C-terminal tail of hirudin(hirudin_ 53-64),which could bind to the anion binding exosite (ABE) of thrombin.Arg-Pro-Pro-Gly-Phe(RPPGF) amino acid sequence,a metabolite of bradykinin,was added to the N-terminus of hirudin_ 53-64.It bound to the active site of thrombin.Additionally,Arg-Gly-Asp(RGD)amino acid sequence,an inibitor of glycoprotein Ⅱb/Ⅲa( GP Ⅱb/Ⅲa) receptor,was linked to C-terminus of hirudin_ 53-64.This 26-animo acid-fused hirudin peptide was artificially synthesized,purified and analysed. Results: Fused hirudin peptide significantly lengthened the activated partial thromboplastin time(APTT),thrombin time(TT)and prothrombin time(PT) and inhibited the amidolytic activity of thrombin.The ADP-induced platelet aggregation was markedly inhibited by fused hirudin peptide. Conclusion: Fused hirudin peptide has activity of antithrombin as well as antiplatelet.Therefore bifunctional anticoagulation peptide has capacity to target various components of haemostatic process and may become more powerful antithrombosis agent.展开更多
A novel Enterococcus faecalis strain designated N J402 was found with high activity of arginine deiminase （ADI）. The optimum condition for catalytic activity was determined in terms of temperature （about 40℃）, th...A novel Enterococcus faecalis strain designated N J402 was found with high activity of arginine deiminase （ADI）. The optimum condition for catalytic activity was determined in terms of temperature （about 40℃）, thermostability （available 37℃） and pH （6-7）. The effects of substrate and product concentration were studied. The effects of various metal ions added in reaction mixtures on the biocatalyst were investigated and ADI of N J402 was found to exhibit Co^2＋ dependence, different from previous reports. Surfactant, cetyl trimethyl ammonium bromide, was one of the most important keys for producing L-citrulline. The enzyme in resting cells possessed the quality of high stability for reuse.展开更多
文摘AIM: To determine serum γ-glutamyltransferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity, and to assess their correlation with demographic and clinical findings in healthy blood donors. METHODS: This cross-sectional study was performed in 934 male blood donors, aged 18 to 68 years, who consecutively attended Tehran blood transfusion service in 2006. All participants were seronegative for HBV or HCV infections, non alcohol users, and all underwent a standard interview and anthropometric tests. Clinical and biochemical parameters including AST, ALT, and GGT activities were determined. Patients taking drugs known to cause hepatic fat deposition were excluded. For AST, ALT, and GGT variables, we used 33.33 and 66.66 percentiles, so that each of them was divided into three tertiles. RESULTS: Mean AST, ALT, and GGT activities were 25.26 ± 12.58 U/L (normal range 5-35 U/L), 33.13 ± 22.98 (normal range 5-35 U/L), and 25.11 ± 18.32 (normal range 6-37 U/L), respectively. By univariate analyses, there were significant associations between increasing AST, ALT, or GGT tertiles and age, body weight, body mass index, and waist and hip circumferences (P < 0.05). By multiple linear regression analyses, ALT was found to be positively correlated with dyslipidemia (B = 6.988, P = 0.038), whereas ALT and AST were negatively correlated with age. AST, ALT, and GGT levels had positive correlation with family history of liver disease (B = 15.763, P < 0.001), (B = 32.345, P < 0.001), (B =24.415, P < 0.001), respectively.CONCLUSION: Although we did not determine the cutoffs of the upper normal limits for AST, ALT, and GGT levels, we would suggest screening asymptomatic patients with dyslipidemia and also subjects with a family history of liver disease.
基金supported by the Basic Scientific Research Foundation of FIO, SOA (2010G13)the National Natural Science Foundation of China (41076108)+1 种基金the Science Foundation for Youth Scholars of State Oceanic Administration (2012131)the Public Welfare Project of Marine Science Research (200805039)
文摘A total of 69 strains of thermophilic bacteria were isolated from water, soil and sediment samples from three Indonesia's hot spring areas (Pantai cermin, Kalianda and Banyu wedang) by using Minimal Synthetic Medium (MSM). The extreme thermophile Brevibacillus sp. PLI-1 was found to produce extracellular thermophilic alkaline protease with optimal activity at 70℃ and pH 8.0-9.0. The molecular weight of the protease was estimated to be around 56 kD by SDS-PAGE. The maximum activity of the protease was 26.54 U mL-1. The protease activity did not decrease after 30 min and still retained more than 70% of relative activity after 60 min at 70℃ and pH 8.0. The ion Mg2+ was found to promote protease activity at both low and high concentrations, whereas Cu2+ and Zn2+ could almost completely inhibit the activity. Divalent cation chelator EDTA inhibited the enzyme activity by 55.06% ± 0.27%, while the inhibition caused by PMSF, Leupeptin, Pepstain A and Benzamidine were 66.78% ± 3.25%, 52.37% ± 0.25%, 62.47% ± 2.96% and 50.99% ± 0.24%, respectively. Based on these observations, the enzyme activity was conspicuously sensitive to the serine and cysteine protease inhibitors. All these results indicated that the protease isolated from the strain PLI-1 was a thermophilic protease and had a high-temperature stability and a pH stability.
文摘AIM: To evaluate serum alanine aminotransferase (ALT)activity in a well-characterized group of uncomplicated obese subjects and its correlation with insulin resistance,plasma adiponectin, and leptin concentrations.METHODS: One hundred and five uncomplicatedobese subjects (87 women, 18 men, age 34.3±9.6 years,BMI 39.9±8.3 kg/m2)were studied. Serum ALT activity was evaluated. Insulin sensitivity was assessed by euglycemic hyperinsulinemic clamp (M index) and fasting insulin. Plasma leptin and adiponectin levels were also measured.RESULTS: Serum ALT concentration in the whole group of uncomplicated obese subjects was 17.73±6.33 U/L with none of the subjects presenting ALT levels greater than 43 U/L and only 9 (11%) women and 3 (19%) men showed ALT levels ＞19 and ＞30 U/L for women and men,respectively. No significant difference was detected in serum ALT levels between severe obese subjects (BMI ＞40 kg/m2) and those with BMI ＜40 kg/m2 (18.63±6.25 vs 17.26±6.02 U/L). ALT was significantly correlated with fasting insulin (r = 0.485, P = 0.02) and triglycerides (r= 0.358, P= 0.03).CONCLUSION: Serum ALT activity is practically normal in uncomplicated obese subjects, independently of their obesity degree. These findings suggest the role of obesityrelated comorbidities and not of BMI as main risk factors for elevated ALT levels in obese subjects.
基金Supported by funding from the Spanish Ministry of Health (grants # PI040384 and # 03/155-2002) awarded to the Spanish Network of Hepatic Encephalopathy Research and a grant from PAI (CTS-532)
文摘AIM： To assess whether portacaval anastomosis （PCA） in rats affects the protein expression and/or activity of glutaminase in kidneys, intestines and in three brain areas of cortex, basal ganglia and cerebellum and to explain the neurological alterations found in hepatic encephalopathy （HE）. METHODS： Sixteen male Wistar rats weighing 250-350 g were grouped into sham-operation control （n=8） or portacaval shunt （n = 8）. Twenty-eight days after the procedure, the animals were sacrificed. The duodenum, kidney and brain were removed, homogenised and mitochondria were isolated. Ammonia was measured in brain and blood. Phosphate-activated glutaminase （PAG） activity was determined by measuring ammonia production following incubation for one hour at 37 ℃ with O-phthalaldehyde （OPA） and specific activity expressed in units per gram of protein （pkat/g of protein）. Protein expression was measured by immunoblotting. RESULTS： Duodenal and kidney PAG activities together with protein content were significantly higher in PCA group than in control or sham-operated rats （duodenum PAG activity was 976.95±268.87μkat/g of protein in PCA rats vs 429.19±126.92.μkat/g of protein in shamoperated rats; kidneys PAG activity was 1259.18±228.79 μkat/g protein in PCA rats vs 669.67±400.8 μkat/g of protein in controls, P〈0.05; duodenal protein content： 173% in PCA vs sham-operated rats; in kidneys the content of protein was 152% in PCA vs sham-operated rats）. PAG activity and protein expression in PCA rats were higher in cortex and basal ganglia than those in shamoperated rats （cortex： 6646.6 ±1870.4 μkat/g of protein vs 3573.8± 2037.4 μkat/g of protein in control rats, P〈 0.01; basal ganglia, PAG activity was 3657.3± 1469.6 μkat/g of protein in PCA rats vs 2271.2±384 μkat/g of protein in sham operated rats, P〈0.05; In the cerebellum, the PAG activity was 2471.6±701.4 μkat/g of protein vs 1452.9 ±567.8 μkat/g of protein in the PCA and sham rats, respectively, P〈0.05; content of protein： cerebral cortex： 162% ±40% vs 100% ± 26%, P〈 0.009; and basal ganglia： 140% ±39% vs 100% ±14%, P〈0.05; but not in cerebellum： 100% ±25% vs 100% ± 16%, P= ns）. CONCLUSION： Increased PAG activity in kidney and duodenum could contribute significantly to the hyperammonaemia in PCA rats, animal model of encephalopathy. PAG is increased in non-synaptic mitochondria from the cortex and basal ganglia and could be implicated in the pathogenesis of hepatic encephalopathy. Therefore, PAG could be a possible target for the treatment of HE or liver dysfunction.
文摘Objective: To investigate whether fused hirudin peptide has both antithrombin and antiplatelet functions. Methods: The core region of fused hirudin was the C-terminal tail of hirudin(hirudin_ 53-64),which could bind to the anion binding exosite (ABE) of thrombin.Arg-Pro-Pro-Gly-Phe(RPPGF) amino acid sequence,a metabolite of bradykinin,was added to the N-terminus of hirudin_ 53-64.It bound to the active site of thrombin.Additionally,Arg-Gly-Asp(RGD)amino acid sequence,an inibitor of glycoprotein Ⅱb/Ⅲa( GP Ⅱb/Ⅲa) receptor,was linked to C-terminus of hirudin_ 53-64.This 26-animo acid-fused hirudin peptide was artificially synthesized,purified and analysed. Results: Fused hirudin peptide significantly lengthened the activated partial thromboplastin time(APTT),thrombin time(TT)and prothrombin time(PT) and inhibited the amidolytic activity of thrombin.The ADP-induced platelet aggregation was markedly inhibited by fused hirudin peptide. Conclusion: Fused hirudin peptide has activity of antithrombin as well as antiplatelet.Therefore bifunctional anticoagulation peptide has capacity to target various components of haemostatic process and may become more powerful antithrombosis agent.
基金Supported by the Innovation Foundation of China (No. 02CJ-13-01-16).
文摘A novel Enterococcus faecalis strain designated N J402 was found with high activity of arginine deiminase （ADI）. The optimum condition for catalytic activity was determined in terms of temperature （about 40℃）, thermostability （available 37℃） and pH （6-7）. The effects of substrate and product concentration were studied. The effects of various metal ions added in reaction mixtures on the biocatalyst were investigated and ADI of N J402 was found to exhibit Co^2＋ dependence, different from previous reports. Surfactant, cetyl trimethyl ammonium bromide, was one of the most important keys for producing L-citrulline. The enzyme in resting cells possessed the quality of high stability for reuse.
