Search results for "Reactive"
showing 10 items of 1469 documents
Hyperhomocysteinemia and Cardiovascular Risk: Effect of Vitamin Supplementation in Risk Reduction
2010
Abstract Homocysteine is a sulfur-containing aminoacid produced during metabolism of methionine. Since 1969 the relationship between altered homocysteine metabolism and both coronary and peripheral atherotrombosis has been known; in recent years experimental evidences have shown that elevated plasma levels of homocysteine are associated with an increased risk of atherosclerosis and cardiovascular ischemic events. Several mechanisms by which elevated homocysteine impairs vascular function have been proposed, including impairment of endothelial function, production of Reactive Oxygen Species (ROS) and consequent oxidation of low-density lipids. Folic acid and B vitamins, required for remethyl…
Impact of therapeutically induced reactive oxygen species and radical scavenging by α-tocopherol on tumor cell adhesion
2007
Many tumor treatment modalities such as ionizing radiation or some chemotherapy induce reactive oxygen species (ROS) resulting in therapeutic cell damage. The aim of this study was to analyze whether such ROS induction may affect the mechanical stability of solid tumor tissue by degradation of the extracellular matrix proteins or by a loss of cell adhesion molecules. Additionally, the protective impact of alpha-tocopherol treatment on these processes was studied. Experimental DS-sarcomas in rats were treated with a combination of localized 44 degrees C hyperthermia, inspiratory hyperoxia and xanthine oxidase in order to induce pronounced oxidative stress. A second group of animals were pret…
Role of glutathione in plant signaling under biotic stress
2012
International audience; Glutathione (GSH) is a non-protein thiol compound which has been repeatedly reported to play an important role in plant responses during biotic stresses. However, our knowledge of glutathione-related molecular mechanisms underlying plant defense responses still remains limited. We first discovered that the Arabidopsis thaliana phytoalexin deficient 2-1 (pad2-1) mutant was linked to glutathione deficiency since the mutation was identified in the GSH1 gene encoding the first enzyme of glutathione biosynthesis: Glutamate Cysteine Ligase (GCL). Interestingly, this glutathione-deficient mutant pad2-1 also displays a high susceptibility to a wide range of invaders. We rece…
Characterization of a new, nonpathogenic mutant of Botrytis cinerea with impaired plant colonization capacity.
2006
International audience; Botrytis cinerea is a necrotrophic pathogen that attacks more than 200 plant species.Here, the nonpathogenic mutant A336, obtained via insertional mutagenesis, was characterized.Mutant A336 was nonpathogenic on leaves and fruits, on intact and wounded tissue, while still able to penetrate the host plant. It grew normally in vitro on rich media but its conidiation pattern was altered. The mutant did not produce oxalic acid and exhibited a modified regulation of the production of some secreted proteins (acid protease 1 and endopolygalacturonase 1). Culture filtrates of the mutant triggered an important oxidative burst in grapevine ( Vitis vinifera ) suspension cells, a…
Role for mitochondrial reactive oxygen species in brain lipid sensing: redox regulation of food intake.
2006
0012-1797 (Print) Journal Article Research Support, Non-U.S. Gov't; The ability for the brain to sense peripheral fuel availability is mainly accomplished within the hypothalamus, which detects ongoing systemic nutrients and adjusts food intake and peripheral metabolism as needed. Here, we hypothesized that mitochondrial reactive oxygen species (ROS) could trigger sensing of nutrients within the hypothalamus. For this purpose, we induced acute hypertriglyceridemia in rats and examined the function of mitochondria in the hypothalamus. Hypertriglyceridemia led to a rapid increase in the mitochondrial respiration in the ventral hypothalamus together with a transient production of ROS. Cerebral…
Design, construction and operational results of a pilot plant for the treatment and valorization of pickling waste solutions
2021
An innovative hybrid technology for both minimizing the waste production and optimizing the pickling process through the continuous control of pickling baths composition has been proposed by means of a pilot-plant installed at the Tecnozinco Srl, Carini (PA) hot-dip galvanizing plant. The recovery process has been accomplished by coupling a diffusion dialysis (DD), where HCl is recovered, a membrane distillation (MD), where HCl is concentrated, and a reactive precipitation (RP), where metal ions are recovered as iron hydroxide and ammonium/zinc chloride solution, to be used in the fluxing baths of the plant. The pilot plant was commissioned and operated using synthetic HCl solutions first a…
Structure and function of the vacuolar Ccc1/VIT1 family of iron transporters and its regulation in fungi
2020
Iron is an essential micronutrient for most living beings since it participates as a redox active cofactor in many biological processes including cellular respiration, lipid biosynthesis, DNA replication and repair, and ribosome biogenesis and recycling. However, when present in excess, iron can participate in Fenton reactions and generate reactive oxygen species that damage cells at the level of proteins, lipids and nucleic acids. Organisms have developed different molecular strategies to protect themselves against the harmful effects of high concentrations of iron. In the case of fungi and plants, detoxification mainly occurs by importing cytosolic iron into the vacuole through the Ccc1/V…
HNO3 partitioning in cirrus clouds
1999
During the 1997 POLSTAR-1 winter campaign in northern Sweden a flight was performed across a cold trough of air (similar or equal to 196 K) in the tropopause region. Measurements of total water vapour, nitric acid, particles and reactive nitrogen (NOy) were taken. The particle measurements indicate that about 3% of the particles in the moist tropospheric air were ice particles. Forward and backward facing NOy inlets were used simultaneously to determine condensed phase HNO3. The combined NOy and particle measurements reveal that less than 1% of a monolayer of NOy could have resided on the ice particles. This casts doubt on the hypothesis that sedimenting cirrus particles generally lead to a…
Disulfide stress and its targets in acute pancreatitis
2014
Under physiological conditions, the balance between ROS production and removal properly maintains the intracellular redox-sensitive signaling as well as the appropriate status of protein thiols and disulfides. However, inflammation among other factors can modify this balance causing a rapid increase in intracellular ROS levels and hence thiol oxidation, eventually leading to oxidative stress. In the case of acute pancreatitis, both redox signaling and oxidative stress seem to contribute to the progression of the severe form of the disease. In this review we will focus on the reversible oxidation of protein cysteines during the course of acute pancreatitis. We describe disulfide stress in an…
Interaction of Human Phagocytes with Pigmentless Aspergillus Conidia
2000
ABSTRACT A defect in the pksP gene of Aspergillus fumigatus is associated with the loss of conidial pigmentation, a profound change of the conidial surface structure, and reduced virulence. The structural change of the conidial surface structure was not observed in similar A. nidulans wA mutants. Our data indicate that the pigment of both species is important for scavenging reactive oxygen species and for protection of conidia against oxidative damage.