Search results for " acting"
showing 10 items of 80 documents
Polyamine Oxidase 5 loss-of-function mutations in Arabidopsis thaliana trigger metabolic and transcriptional reprogramming and promote salt stress to…
2017
The family of polyamine oxidases (PAO) in Arabidopsis (AtPAO1-5) mediates polyamine (PA) back-conversion, which reverses the PA biosynthetic pathway from spermine, and its structural isomer thermospermine (tSpm), into spermidine and then putrescine. Here, we have studied the involvement of PA back-conversion in Arabidopsis salinity tolerance. AtPAO5 is the Arabidopsis PAO gene member most transcriptionally induced by salt stress. Two independent loss-of-function mutants (atpao5-2 and atpao5-3) were found to exhibit constitutively higher tSpm levels, with associated increased salt tolerance. Using global transcriptional and metabolomic analyses, the underlying mechanisms were studied. Stimul…
Kinetic studies on protoporphyrinogen oxidase inhibition by diphenyl ether herbicides
1991
Diphenyl ethers (DPEs) and related herbicides are powerful inhibitors of protoporphyrinogen oxidase, an enzyme involved in the biosynthesis of haems and chlorophylls. The inhibition kinetics of protoporphyrinogen oxidase of various origins by four DPEs, (methyl)-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (acifluorfen and its methyl ester, acifluorfen-methyl), methyl-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-chlorobenzoate (LS 820340) and methyl-5-[2-chloro-5-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (RH 5348), were studied. The inhibitions of the enzymes from maize (Zea mays) mitochondrial and etiochloroplastic membranes and mouse liver mitochondrial membranes were com…
Characterization of (3H) acifluorfen binding to purified pea etioplasts, and evidence that protoporphyrinogen oxidase specifically binds acifluorfen
1992
It is now generally accepted that protoporphyrinogen oxidase is the target-enzyme for diphenylether-type herbicides. Recent studies [Camadro, J-M., Matringe, M., Scalla, R. & Labbe, P. (1991) Biochem. J. 277, 17–21] have revealed that in maize, diphenyl ethers competitively inhibit protoporphyrinogen oxidase with respect to its substrate, protoporphyrinogen IX. In this study, we show that, in purified pea etioplast, [3H]acifluorfen specifically binds to a single class of high-affinity binding sites with an apparent dissociation constant of 6.2 ± 1.3 nM and a maximum density of 29 ± 5 nmol/g protein. [3H]Acifluorfen binding reaches equilibrium in about 1 min at 30°C. Half dissociation occurs…
Synthesis and properties of a photoaffinity labeling reagent for protoporphyrinogen oxidases, the target enzymes of diphenyl ether herbicides
1994
A diazoketone 3 has been synthesized in two steps from acifluorfen 1, a diphenyl ether herbicide. Like the parent compound 1, the diazoketone 3 is toxic to plant cells and inhibits protoporphyrinogen oxidase, the molecular target of diphenyl ether herbicides. On photolysis of 3 in methanol, the generated carbene mainly undergoes the Wolff rearrangement to a ketene which further adds methanol, but many other products are observed. A tritiated derivative of 3 has been prepared which is suitable for photoaffinity labeling experiments.
Hepatitis C Virus Eradication by Direct Antiviral Agents Improves Carotid Atherosclerosis in patients with Severe Liver Fibrosis.
2018
Abstract BACKGROUND AND AIM: Recent studies suggest an association between HCV infection and cardiovascular damage, including carotid atherosclerosis, with a possible effect of HCV clearance on cardiovascular outcomes. We aimed to examine whether HCV eradication by direct antiviral agents (DAA) improves carotid atherosclerosis in HCV-infected patients with advanced fibrosis/compensated cirrhosis. MATERIALS AND METHODS: One hundred eighty-two consecutive HCV patients with advanced fibrosis or compensated cirrhosis were evaluated by virological, anthropometric and metabolic measurements. All patients underwent DAA-based antiviral therapy according to AISF/EASL guidelines. Intima-media thickne…
Real life experiences in HCV management in 2018
2019
Introduction: Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, with approximately 71 million chronically infected individuals worldwide. Treatment of chronic hepatitis C has considerably improved in the last few years thanks to the introduction of direct-acting antivirals able to achieve sustained virological response in more than 95% of patients. Successful anti-HCV treatment can halt liver disease progression and solve the HCV-related extra-hepatic manifestations, eventually reducing liver-related and overall mortality. Areas covered: With the aim to respond to unmet needs in patient’s identification, universal access to antiviral therapy and treatment optimiza…
Hepatocellular carcinoma and direct-acting antivirals: A never ending story?
2017
Further delineation of a rare recessive encephalomyopathy linked to mutations in GFER thanks to data sharing of whole exome sequencing data
2017
Background Alterations in GFER gene have been associated with progressive mitochondrial myopathy, congenital cataracts, hearing loss, developmental delay, lactic acidosis and respiratory chain deficiency in 3 siblings born to consanguineous Moroccan parents by homozygosity mapping and candidate gene approach (OMIM#613076). Next generation sequencing recently confirmed this association by the finding of compound heterozygous variants in 19-year-old girl with a strikingly similar phenotype, but this ultra-rare entity remains however unknown from most of the scientific community. Materials and methods Whole exome sequencing was performed as part of a "diagnostic odyssey" for suspected mitochon…
Hepatitis C virus early kinetics and resistance-associated substitution dynamics during antiviral therapy with direct-acting antivirals
2018
The emergence of resistance-associated substitutions (RASs) can compromise the high efficacy of direct-acting antivirals (DAAs). Little is known about RASs selection at very early time points during DAA treatment. Therefore, we analyzed the potential emergence of RASs immediately after therapy initiation. Samples of 71 patients treated with different DAAs were collected at baseline, during therapy (hours 4 and 8; days 1-7; weeks 2-4) or until target not detected. HCV-RNA levels were determined by qPCR, and RASs were detected by deep sequencing. Sixty-three (89%) patients achieved a sustained virological response (SVR), 7 (10%) relapsed, and 1 (1%) experienced a breakthrough. Almost all non-…