AIM: To investigate the effects of vitamins (A, C and E) on liver injury induced by ethanol administration during liver regeneration in rats. METHODS: Male Wistar rats subjected to 70% partial hepatectomy were divided...AIM: To investigate the effects of vitamins (A, C and E) on liver injury induced by ethanol administration during liver regeneration in rats. METHODS: Male Wistar rats subjected to 70% partial hepatectomy were divided into five groups (groups 1-5). During the experiment, animals of Group 1 drank only water. The other four groups (2-5) drank 30 mL of ethanol/L of water. Group 3 additionally received vitamin A, those of group 4 vitamin C and those of group 5 received vitamin E. Subsequently serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin and bilirubin were measured colorimetrically. Lipid peroxidation (thiobarbituric-acid reactive substances, TBARS) both in plasma and liver was measured, as well as liver mass gain assessment and total DNA. RESULTS: Compared with sham group, serum AST and ALT increased significantly under ethanol treatment (43% and 93%, respectively, with P < 0.05). Vitamin C and vitamin E treatment attenuated the ethanol-induced increases in ALT and AST activity. Ethanol treatment also decreased serum albumin concentration compared to sham group (3.1 ± 0.4 g/dL vs 4.5 ± 0.2 g/dL; P < 0.05). During liver regeneration vitamins C and E significantly ameliorated liver injury for ethanol administration in hepatic lipid peroxidation (4.92 nmol/mg and 4.25 nmol/mg vs 14.78 nmol/mg, respectively, with P < 0.05). In association with hepatic injury, ethanol administration caused a significant increase in both hepatic and plasma lipid peroxidation. Vitamins (C and E) treatment attenuated hepatic and plasma lipid peroxidation. CONCLUSION: Vitamins C and E protect against liver injury and dysfunction, attenuate lipid peroxidation, and thus appear to be significantly more effective than vitamin A against ethanol-mediated toxic effects during liver regeneration.展开更多
The desolvation of erythromycin acetone solvate was investigated under non-isothermal conditions by a thermogravimetric analyzer. This paper emphasized the kinetic analysis of non-isothermal TG-DTA data by Achar metho...The desolvation of erythromycin acetone solvate was investigated under non-isothermal conditions by a thermogravimetric analyzer. This paper emphasized the kinetic analysis of non-isothermal TG-DTA data by Achar method and Coats-Redfern method to fit various solid-state reaction models, and to achieve kinetic parameters of desolvation. The mechanism of thermal desolvation was evaluated using the kinetic compensation effect. The results show that kinetics of desolvation of erythromycin acetone solvate was compatible with the mechanism of a two-dimensional diffusion controlled and was best expressed by Valensi equation. Corresponding to the integral method and the differential method, the activation energy of desolvation of erythromycin acetone solvate was estimated to be 51.26—57.11 kJ/mol, and the pre-exponential factor was 8.077×106 s-1—4.326×107 s-1, respectively.展开更多
An immobilized cell membrane bioreaction system was developed to promote cell stability. The hollow fiber membrane bioreactor with immobilized Pseudomonas putida cells, operating in continual repeated batch operation ...An immobilized cell membrane bioreaction system was developed to promote cell stability. The hollow fiber membrane bioreactor with immobilized Pseudomonas putida cells, operating in continual repeated batch operation mode was used for producing D-p-hydroxyphenylglycine from DL-5-p-hydroxyphenyl hydantoin. The concentration of N-carbamyl-D-p-hydroxyphenylglycine and D-p-hydroxyphenylglycine in the efflux was analyzed by high performance liquid chromatography at different intervals.展开更多
The reactions between gatifloxacin(GFX) and various one-electron oxidants,such as ˙OH,N3˙,Br2˙ˉ,and SO4˙ˉ,have been studied by pulse radiolysis techniques.The GFX radical anion formed in the reaction of GFX with...The reactions between gatifloxacin(GFX) and various one-electron oxidants,such as ˙OH,N3˙,Br2˙ˉ,and SO4˙ˉ,have been studied by pulse radiolysis techniques.The GFX radical anion formed in the reaction of GFX with eaqˉ could either be protonated or deprotonated,and the absorption of GFX radical anion was located at 390 nm.The transient species produced by the reaction of GFX with ˙OH radical shows a broad band in the 380?600 nm region with a shoulder,while the oxidation by N3˙,SO4˙ˉ,and Br2˙ˉ results in an absorption band with λmax = 370 nm.At neutral condition(pH 7),the rate constants of GFX reacting with ˙OH,N3˙,Br2˙ˉ,SO4˙ˉ and eaqˉ are estimated to be 1.0 × 1010,3.1 × 109,2.8 × 109,3.0 × 109,and 1.8 × 1010 dm3 mol?1 s?1,respectively.From the pH dependence on the formation of electron adducts and on the rate constant of GFX with eaqˉ,the pKa of GFX radical anion is estimated to be 5.5 and 9.3.展开更多
文摘AIM: To investigate the effects of vitamins (A, C and E) on liver injury induced by ethanol administration during liver regeneration in rats. METHODS: Male Wistar rats subjected to 70% partial hepatectomy were divided into five groups (groups 1-5). During the experiment, animals of Group 1 drank only water. The other four groups (2-5) drank 30 mL of ethanol/L of water. Group 3 additionally received vitamin A, those of group 4 vitamin C and those of group 5 received vitamin E. Subsequently serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin and bilirubin were measured colorimetrically. Lipid peroxidation (thiobarbituric-acid reactive substances, TBARS) both in plasma and liver was measured, as well as liver mass gain assessment and total DNA. RESULTS: Compared with sham group, serum AST and ALT increased significantly under ethanol treatment (43% and 93%, respectively, with P < 0.05). Vitamin C and vitamin E treatment attenuated the ethanol-induced increases in ALT and AST activity. Ethanol treatment also decreased serum albumin concentration compared to sham group (3.1 ± 0.4 g/dL vs 4.5 ± 0.2 g/dL; P < 0.05). During liver regeneration vitamins C and E significantly ameliorated liver injury for ethanol administration in hepatic lipid peroxidation (4.92 nmol/mg and 4.25 nmol/mg vs 14.78 nmol/mg, respectively, with P < 0.05). In association with hepatic injury, ethanol administration caused a significant increase in both hepatic and plasma lipid peroxidation. Vitamins (C and E) treatment attenuated hepatic and plasma lipid peroxidation. CONCLUSION: Vitamins C and E protect against liver injury and dysfunction, attenuate lipid peroxidation, and thus appear to be significantly more effective than vitamin A against ethanol-mediated toxic effects during liver regeneration.
文摘The desolvation of erythromycin acetone solvate was investigated under non-isothermal conditions by a thermogravimetric analyzer. This paper emphasized the kinetic analysis of non-isothermal TG-DTA data by Achar method and Coats-Redfern method to fit various solid-state reaction models, and to achieve kinetic parameters of desolvation. The mechanism of thermal desolvation was evaluated using the kinetic compensation effect. The results show that kinetics of desolvation of erythromycin acetone solvate was compatible with the mechanism of a two-dimensional diffusion controlled and was best expressed by Valensi equation. Corresponding to the integral method and the differential method, the activation energy of desolvation of erythromycin acetone solvate was estimated to be 51.26—57.11 kJ/mol, and the pre-exponential factor was 8.077×106 s-1—4.326×107 s-1, respectively.
文摘An immobilized cell membrane bioreaction system was developed to promote cell stability. The hollow fiber membrane bioreactor with immobilized Pseudomonas putida cells, operating in continual repeated batch operation mode was used for producing D-p-hydroxyphenylglycine from DL-5-p-hydroxyphenyl hydantoin. The concentration of N-carbamyl-D-p-hydroxyphenylglycine and D-p-hydroxyphenylglycine in the efflux was analyzed by high performance liquid chromatography at different intervals.
基金supported by the National Natural Science Foundation of China (21173252)
文摘The reactions between gatifloxacin(GFX) and various one-electron oxidants,such as ˙OH,N3˙,Br2˙ˉ,and SO4˙ˉ,have been studied by pulse radiolysis techniques.The GFX radical anion formed in the reaction of GFX with eaqˉ could either be protonated or deprotonated,and the absorption of GFX radical anion was located at 390 nm.The transient species produced by the reaction of GFX with ˙OH radical shows a broad band in the 380?600 nm region with a shoulder,while the oxidation by N3˙,SO4˙ˉ,and Br2˙ˉ results in an absorption band with λmax = 370 nm.At neutral condition(pH 7),the rate constants of GFX reacting with ˙OH,N3˙,Br2˙ˉ,SO4˙ˉ and eaqˉ are estimated to be 1.0 × 1010,3.1 × 109,2.8 × 109,3.0 × 109,and 1.8 × 1010 dm3 mol?1 s?1,respectively.From the pH dependence on the formation of electron adducts and on the rate constant of GFX with eaqˉ,the pKa of GFX radical anion is estimated to be 5.5 and 9.3.
