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Journal ArticleDOI

A Rapid Spectrophotometric Method for the Determination of Nitrite in Water.

23 Jan 1990-ChemInform (Wiley)-Vol. 21, Iss: 4
About: This article is published in ChemInform.The article was published on 1990-01-23. It has received 152 citations till now. The article focuses on the topics: Nitrite.
Citations
More filters
Journal ArticleDOI
TL;DR: A bacterium tentatively identified as a Pseudomonas sp.
Abstract: A bacterium tentatively identified as a Pseudomonas sp. was isolated from a laboratory aquifer column in which toluene was degraded under denitrifying conditions. The organism mineralized toluene in pure culture in the absence of molecular oxygen. In carbon balance studies using [ring-UL-14C]toluene, more than 50% of the radioactivity was recovered as 14CO2. Nitrate and nitrous oxide served as electron acceptors for toluene mineralization. The organism was also able to degrade m-xylene, benzoate, benzaldehyde, p-cresol, p-hydroxy-benzaldehyde, p-hydroxybenzoate and cyclohexanecarboxylic acid in the absence of molecular oxygen.

182 citations

Journal ArticleDOI
TL;DR: This bacterium was characterized taxonomically as being a member of the genus Burkholderia and was designated strain NF100, which first hydrolyzed an organophosphate bond of fenitrothion, forming 3-methyl-4-nitrophenol, which was further metabolized to methylhydroquinone.
Abstract: A bacterium capable of utilizing fenitrothion (O,O-dimethyl O-4-nitro-m-tolyl phosphorothioate) as a sole carbon source was isolated from fenitrothion-treated soil. This bacterium was characterized taxonomically as being a member of the genus Burkholderia and was designated strain NF100. NF100 first hydrolyzed an organophosphate bond of fenitrothion, forming 3-methyl-4-nitrophenol, which was further metabolized to methylhydroquinone. The ability to degrade fenitrothion was found to be encoded on two plasmids, pNF1 and pNF2.

119 citations


Cites methods from "A Rapid Spectrophotometric Method f..."

  • ...Nitrite was determined by the modified Griess-Ilosvay method (11)....

    [...]

Journal ArticleDOI
TL;DR: Evidence is provided that 18β-GA exerts hepatoprotective effects against CP through induction of antioxidant defenses and suppression of inflammatory response, which protects liver against the toxic effect of chemotherapeutic alkylating agents via activation of Nrf2 and PPARγ.
Abstract: 18β-Glycyrrhetinic acid (18β-GA) has been proposed as a promising hepatoprotective agent. The current study aimed to investigate the protective action and the possible mechanisms of 18β-GA against cyclophosphamide (CP)-induced liver injury in rats, focusing on the role of peroxisome proliferator-activated receptor gamma (PPARγ) and NF-E2-related factor-2 (Nrf2). Rats were administered 18β-GA at doses 25 and 50 mg/kg 2 weeks prior to CP injection. Five days after CP administration, animals were sacrificed and samples were collected. CP induced hepatic damage evidenced by the histopathological changes and significant increase in serum pro-inflammatory cytokines, liver marker enzymes, and liver lipid peroxidation and nitric oxide (NO) levels. 18β-GA counteracted CP-induced oxidative stress and inflammation as assessed by restoration of the antioxidant defenses and diminishing of pro-inflammatory cytokines, lipid peroxidation, and NO production. These hepatoprotective effects appear to depend on activation of Nrf2 and PPARγ, and subsequent suppression of nuclear factor-kappa B. In conclusion, the present study provides evidence that 18β-GA exerts hepatoprotective effects against CP through induction of antioxidant defenses and suppression of inflammatory response. This report also confers new information that 18β-GA protects liver against the toxic effect of chemotherapeutic alkylating agents via activation of Nrf2 and PPARγ.

116 citations


Cites methods from "A Rapid Spectrophotometric Method f..."

  • ...Nitric oxide (NO) was determined according to the method of Montgomery and Dymock (1961) using reagent kit purchased from Biodiagnostics (Egypt)....

    [...]

Journal ArticleDOI
TL;DR: The promising anticonvulsant and potent antioxidant effects of curcumin and NSO are reflected in reducing oxidative stress, excitability and the induction of seizures in epileptic animals and improving some of the adverse effects of antiepileptic drugs.
Abstract: Oxidative stress has been implicated to play a role in epileptogenesis and pilocarpine-induced seizures. The present study aims to evaluate the antioxidant effects of curcumin, Nigella sativa oil (NSO) and valproate on the levels of malondialdehyde, nitric oxide, reduced glutathione and the activities of catalase, Na+, K+-ATPase and acetylcholinesterase in the hippocampus of pilocarpine-treated rats. The animal model of epilepsy was induced by pilocarpine and left for 22 days to establish the chronic phase of epilepsy. These animals were then treated with curcumin, NSO or valproate for 21 days. The data revealed evidence of oxidative stress in the hippocampus of pilocarpinized rats as indicated by the increased nitric oxide levels and the decreased glutathione levels and catalase activity. Moreover, a decrease in Na+, K+-ATPase activity and an increase in acetylcholinesterase activity occurred in the hippocampus after pilocarpine. Treatment with curcumin, NSO or valproate ameliorated most of the changes induced by pilocarpine and restored Na+, K+-ATPase activity in the hippocampus to control levels. This study reflects the promising anticonvulsant and potent antioxidant effects of curcumin and NSO in reducing oxidative stress, excitability and the induction of seizures in epileptic animals and improving some of the adverse effects of antiepileptic drugs.

109 citations


Cites methods from "A Rapid Spectrophotometric Method f..."

  • ...method of Montgomery and Dymock [30] which is based...

    [...]

  • ...This method is based on the spectrophotometric method of Montgomery and Dymock [30] which is based on the measurement of endogenous nitrite concentration as an indicator of nitric oxide production....

    [...]

Journal ArticleDOI
TL;DR: Ochrobactrum sp B2, a methyl parathion-degrading bacterium, was proved to be capable of using p-nitrophenol (PNP) as carbon and energy source as mentioned in this paper.

94 citations


Cites methods from "A Rapid Spectrophotometric Method f..."

  • ...…pressure of 71 bar, column temperature at 40 1C. Sample volume was 5ml. Nitrite ion was quantitatively determined based on the standard curves prepared using sodium nitrite (DU-800 spectrophotometer, Beckman Coutler Inc., Fullerton, California, USA) by the method of Montgomery and Dymock (1961)....

    [...]

References
More filters
Journal ArticleDOI
TL;DR: A bacterium tentatively identified as a Pseudomonas sp.
Abstract: A bacterium tentatively identified as a Pseudomonas sp. was isolated from a laboratory aquifer column in which toluene was degraded under denitrifying conditions. The organism mineralized toluene in pure culture in the absence of molecular oxygen. In carbon balance studies using [ring-UL-14C]toluene, more than 50% of the radioactivity was recovered as 14CO2. Nitrate and nitrous oxide served as electron acceptors for toluene mineralization. The organism was also able to degrade m-xylene, benzoate, benzaldehyde, p-cresol, p-hydroxy-benzaldehyde, p-hydroxybenzoate and cyclohexanecarboxylic acid in the absence of molecular oxygen.

182 citations

Journal ArticleDOI
TL;DR: These findings provide the first genetic evidence linking dissimilatory metal reduction to type II protein secretion and provide additional biochemical evidence supporting outer membrane localization of S. putrefaciens proteins involved in anaerobic respiration on Fe(III) and Mn(IV).
Abstract: Shewanella putrefaciens strain 200 respires anaerobically on a wide range of compounds as the sole terminal electron acceptor, including ferric iron [Fe(III)] and manganese oxide [Mn(IV)]. Previous studies demonstrated that a 23.3-kb S. putrefaciens wild-type DNA fragment conferred metal reduction capability to a set of respiratory mutants with impaired Fe(III) and Mn(IV) reduction activities (T. DiChristina and E. DeLong, J. Bacteriol. 176:1468-1474, 1994). In the present study, the smallest complementing fragment was found to contain one open reading frame (ORF) (ferE) whose translated product displayed 87% sequence similarity to Aeromonas hydrophila ExeE, a member of the PulE (GspE) family of proteins found in type II protein secretion systems. Insertional mutants E726 and E912, constructed by targeted replacement of wild-type ferE with an insertionally inactivated ferE construct, were unable to respire anaerobically on Fe(III) or Mn(IV) yet retained the ability to grow on all other terminal electron acceptors. Nucleotide sequence analysis of regions flanking ferE revealed the presence of one partial and two complete ORFs whose translated products displayed 55 to 70% sequence similarity to the PulD, -F, and -G homologs of type II secretion systems. A contiguous cluster of 12 type II secretion genes (pulC to -N homologs) was found in the unannotated genome sequence of Shewanella oneidensis (formerly S. putrefaciens) MR-1. A 91-kDa heme-containing protein involved in Fe(III) reduction was present in the peripheral proteins loosely attached to the outside face of the outer membrane of the wild-type and complemented (Fer+) B31 transconjugates yet was missing from this location in Fer mutants E912 and B31 and in uncomplemented (Fer-) B31 transconjugates. Membrane fractionation studies with the wild-type strain supported this finding: the 91-kDa heme-containing protein was detected with the outer membrane fraction and not with the inner membrane or soluble fraction. These findings provide the first genetic evidence linking dissimilatory metal reduction to type II protein secretion and provide additional biochemical evidence supporting outer membrane localization of S. putrefaciens proteins involved in anaerobic respiration on Fe(III) and Mn(IV).

171 citations

Journal ArticleDOI
TL;DR: This bacterium was characterized taxonomically as being a member of the genus Burkholderia and was designated strain NF100, which first hydrolyzed an organophosphate bond of fenitrothion, forming 3-methyl-4-nitrophenol, which was further metabolized to methylhydroquinone.
Abstract: A bacterium capable of utilizing fenitrothion (O,O-dimethyl O-4-nitro-m-tolyl phosphorothioate) as a sole carbon source was isolated from fenitrothion-treated soil. This bacterium was characterized taxonomically as being a member of the genus Burkholderia and was designated strain NF100. NF100 first hydrolyzed an organophosphate bond of fenitrothion, forming 3-methyl-4-nitrophenol, which was further metabolized to methylhydroquinone. The ability to degrade fenitrothion was found to be encoded on two plasmids, pNF1 and pNF2.

119 citations

Journal ArticleDOI
TL;DR: Evidence is provided that 18β-GA exerts hepatoprotective effects against CP through induction of antioxidant defenses and suppression of inflammatory response, which protects liver against the toxic effect of chemotherapeutic alkylating agents via activation of Nrf2 and PPARγ.
Abstract: 18β-Glycyrrhetinic acid (18β-GA) has been proposed as a promising hepatoprotective agent. The current study aimed to investigate the protective action and the possible mechanisms of 18β-GA against cyclophosphamide (CP)-induced liver injury in rats, focusing on the role of peroxisome proliferator-activated receptor gamma (PPARγ) and NF-E2-related factor-2 (Nrf2). Rats were administered 18β-GA at doses 25 and 50 mg/kg 2 weeks prior to CP injection. Five days after CP administration, animals were sacrificed and samples were collected. CP induced hepatic damage evidenced by the histopathological changes and significant increase in serum pro-inflammatory cytokines, liver marker enzymes, and liver lipid peroxidation and nitric oxide (NO) levels. 18β-GA counteracted CP-induced oxidative stress and inflammation as assessed by restoration of the antioxidant defenses and diminishing of pro-inflammatory cytokines, lipid peroxidation, and NO production. These hepatoprotective effects appear to depend on activation of Nrf2 and PPARγ, and subsequent suppression of nuclear factor-kappa B. In conclusion, the present study provides evidence that 18β-GA exerts hepatoprotective effects against CP through induction of antioxidant defenses and suppression of inflammatory response. This report also confers new information that 18β-GA protects liver against the toxic effect of chemotherapeutic alkylating agents via activation of Nrf2 and PPARγ.

116 citations

Journal ArticleDOI
TL;DR: The promising anticonvulsant and potent antioxidant effects of curcumin and NSO are reflected in reducing oxidative stress, excitability and the induction of seizures in epileptic animals and improving some of the adverse effects of antiepileptic drugs.
Abstract: Oxidative stress has been implicated to play a role in epileptogenesis and pilocarpine-induced seizures. The present study aims to evaluate the antioxidant effects of curcumin, Nigella sativa oil (NSO) and valproate on the levels of malondialdehyde, nitric oxide, reduced glutathione and the activities of catalase, Na+, K+-ATPase and acetylcholinesterase in the hippocampus of pilocarpine-treated rats. The animal model of epilepsy was induced by pilocarpine and left for 22 days to establish the chronic phase of epilepsy. These animals were then treated with curcumin, NSO or valproate for 21 days. The data revealed evidence of oxidative stress in the hippocampus of pilocarpinized rats as indicated by the increased nitric oxide levels and the decreased glutathione levels and catalase activity. Moreover, a decrease in Na+, K+-ATPase activity and an increase in acetylcholinesterase activity occurred in the hippocampus after pilocarpine. Treatment with curcumin, NSO or valproate ameliorated most of the changes induced by pilocarpine and restored Na+, K+-ATPase activity in the hippocampus to control levels. This study reflects the promising anticonvulsant and potent antioxidant effects of curcumin and NSO in reducing oxidative stress, excitability and the induction of seizures in epileptic animals and improving some of the adverse effects of antiepileptic drugs.

109 citations