Search results for "REDUCTASE"
showing 10 items of 798 documents
MTHFR 677C → T genotype modulates the effect of a 5-year supplementation with B-vitamins on homocysteine concentration: The SU.FOL.OM3 randomized con…
2018
Aims To study how MTHFR 677C→T genotype modulates the effect of supplementation with B-vitamins on total homocysteine (tHcy) and B-vitamin concentrations. Methods 2381 patients with a personal history of cardiovascular disease were randomly assigned to one of four groups: 1) B-vitamins alone (560 μg of 5-methyl-THF, 3 mg of vitamin B6 and 20 μg of vitamin B12), 2) n-3 fatty acids alone (600 mg of EPA and DHA in a 2:1 ratio), 3) B-vitamins and n-3 fatty acids, and 4) placebo. Participants were followed up for 4.7 years. At baseline and annually thereafter, biological parameters were assessed. Multivariate and linear mixed models were fit to study the interaction between B-vitamins and MTHFR …
Disentangling the rhizosphere effect on nitrate reducers and denitrifiers: insight into the role of root exudates.
2008
International audience; To determine to which extent root-derived carbon contributes to the effects of plants on nitrate reducers and denitrifiers, four solutions containing different proportions of sugar, organic acids and amino acids mimicking maize root exudates were added daily to soil microcosms at a concentration of 150 μg C g−1 of soil. Water-amended soils were used as controls. After 1 month, the size and structure of the nitrate reducer and denitrifier communities were analysed using the narG and napA, and the nirK, nirS and nosZ genes as molecular markers respectively. Addition of artificial root exudates (ARE) did not strongly affect the structure or the density of nitrate reduce…
Seasonal dynamics of biomarkers in infaunal clam Macoma balthica from the Gulf of Riga (Baltic Sea)
2014
Abstract Biomarkers are often regarded as “early warning” signals of environmental pollution; however seasonal changes are mentioned as one of the most important factor that influences the activity of biomarkers. The aim of our study was to assess the importance of seasonal variation of selected contaminant biomarkers in Macoma balthica to provide background information for further environmental surveys in the Gulf of Riga. Seasonal variation of biomarkers (acetylcholinesterase (AChE), catalase (CAT), glutathione reductase (GR) and glutathione- S -transferase (GST)) was measured in infaunal clam M . balthica from the southern part of the Gulf of Riga. The majority of biomarkers (GST, CAT an…
Physiology of Zymomonas mobilis: Some Unanswered Questions
2006
The ethanol-producing bacterium Zymomonas mobilis can serve as a model organism for the study of rapid catabolism and inefficient energy conversion in bacteria. Some basic aspects of its physiology still remain poorly understood. Here, the energy-spilling pathways during uncoupled growth, the structure and function of electron transport chain, and the possible reasons for the inefficient oxidative phosphorylation are analysed. Also, the interaction between ethanol synthesis and respiration is considered. The search for mechanisms of futile transmembrane proton cycling, as well as identification of respiratory electron transport complexes, like the energy-coupling NAD(P)H:quinone oxidoreduct…
New evidence for the multiplicity of ubiquinone- and inhibitor-binding sites in the mitochondrial complex I.
2000
Determination of the number of ubiquinone- and inhibitor-binding sites in the mitochondrial complex I (NADH:ubiquinone oxidoreductase) is a controversial question with a direct implication for elaborating a suitable model to explain the bioenergetic mechanism of this complicated enzyme. We have used combinations of both selective inhibitors and common ubiquinone-like substrates to demonstrate the multiplicity of the reaction centers in the complex I in contrast with competition studies that have suggested the existence of a unique binding site for ubiquinone. Our results provide new evidence for the existence of at least two freely exchangeable ubiquinone-binding sites with different specif…
Comparative genetic diversity of the narG, nosZ, and 16S rRNA genes in fluorescent Pseudomonads
2003
ABSTRACT The diversity of the membrane-bound nitrate reductase ( narG ) and nitrous oxide reductase ( nosZ ) genes in fluorescent pseudomonads isolated from soil and rhizosphere environments was characterized together with that of the 16S rRNA gene by a PCR-restriction fragment length polymorphism assay. Fragments of 1,008 bp and 1,433 bp were amplified via PCR with primers specific for the narG and nosZ genes, respectively. The presence of the narG and nosZ genes in the bacterial strains was confirmed by hybridization of the genomic DNA and the PCR products with the corresponding probes. The ability of the strains to either reduce nitrate or totally dissimilate nitrogen was assessed. Overa…
Melatonin activates the peroxidase-oxidase reaction and promotes oscillations.
2001
We have studied the peroxidase-oxidase reaction with NADH and O2 as substrates and melatonin as a cofactor in a semibatch reactor. We show for the first time that melatonin is an activator of the reaction catalyzed by enzymes from both plant and animal sources. Furthermore, melatonin promotes oscillatory dynamics in the pH range from 5 to 6. The frequency of the oscillations depends on the pH such that an increase in pH was accompanied by a decrease in frequency. Conversely, an increase in the flow rate of NADH or an increase in the average concentration of NADH resulted in an increase in oscillation frequency. Complex dynamics were not observed with melatonin as a cofactor. These results a…
Profiling the physiological and molecular response to sulfonamidic drag in Procambarus clarkii
2014
Sulfamethoxazole (SMZ) is one of the most widely employed sulfonamides. Because of the widespread use of SMZ, a considerable amount is indeed expected to be introduced into the environment. The cytotoxicity of SMZ relies mainly on arylhydroxylamine metabolites (S-NOH) of SMZ and it is associated with the production of reactive oxygen species (ROS). There is limited information about the toxic potential of SMZ at the cellular and molecular levels, especially in aquatic and/or non-target organisms. In the present study, the red swamp crayfish (Procambarus clarkii), being tolerant to extreme environmental conditions and resistant to disease, was used as a model organism to profile the molecula…
Antioxidant effect of Ajuga iva aqueous extract in streptozotocin-induced diabetic rats.
2009
The purpose of this study was to investigate the possible antioxidant effect of an aqueous extract of Ajuga iva (Ai) in streptozotocin (STZ)-induced diabetic rats. Twelve diabetic rats were divided into two groups fed a casein diet supplemented or not with Ai (0.5%), for 4 weeks. In vitro, the Ai extract possessed a very high antioxidant effect (1 mg/ml was similar to those of trolox 300 mmol/l). The results indicated that plasma thiobarbituric acid reactive substances (TBARS) values were reduced by 41% in Ai-treated compared with untreated diabetic rats. TBARS concentrations were lower 1.5-fold in liver, 1.8-fold in heart, 1.9-fold in muscle and 2.1-fold in brain in Ai-treated than untreat…
Non lipid, dose-dependent effects of pravastatin treatment on hemostatic system and inflammatory response
2000
Objectives: The aim of the present study was to evaluate the effects of pravastatin treatment on lipid, inflammation, and coagulation parameters in patients suffering from myocardial infarction with or without carotid atherosclerotic lesions (groups 1 and 2, respectively). Methods: In the first phase of the study, a cross-sectional comparison of lipid, inflammation, and coagulation parameters was performed between the patients and the control group (group 3). Highly significant differences in these parameters were observed, especially in group 1. In the second phase of the study, we assessed the effects of a persistent reduction in cholesterol synthesis induced by increasing doses of pravas…