Search results for " Free radical"
showing 10 items of 24 documents
Training session intensity affects plasma redox status in amateur rhythmic gymnasts
2016
Purpose: The aim of this study was to examine systemic responses of oxidant/antioxidant status following 2 training sessions of different intensity in amateur rhythmic gymnasts. Methods: Before the experimental training, 10 female gymnasts performed a gradually increased exercise test to assess maximal heart rate, maximal oxygen consumption, and anaerobic threshold. They executed 2 intermittent training sessions separated by 48 h of recovery (48 h-post R): the first was performed at low-moderate intensity (LMI) and the second at high intensity (HI). Blood samples were collected immediately pre- and post-training and 48 h-post R. Hydroperoxide level (OxL) and total antioxidant capacity (TAC)…
The Burden of Respiratory Syncytial Virus Disease in Pre-Term Infants
2015
This mini-review summarises the risk factors for acquiring Respiratory Syncitial Virus (RSV) infection, and describes the harmful effects of the infection in pre-term infants. Moreover, theoretical considerations are discussed for the prevention of RSV infection in high-risk infant categories, such as pre-term infants. Background: Neonates positive for RSV are more prone to severe infection than neonates infected with other common respiratory viruses. Despite RSV infection being more common in late neonates than in early ones, pre-term infants ≤ 35 wk gestational age (GA) are at high risk for developing severe RSV disease. Efforts to prevent infection include case management, vaccination an…
Biomarkers of oxidative and nitrosative damage in Alzheimer's disease and mild cognitive impairment
2009
Alzheimer's disease (AD) is the most common type of dementia in the elderly. Products of oxidative and nitrosative stress (OS and NS, respectively) accumulate with aging, which is the main risk factor for AD. This provides the basis for the involvement of OS and NS in AD pathogenesis. OS and NS occur in biological systems due to the dysregulation of the redox balance, caused by a deficiency of antioxidants and/or the overproduction of free radicals. Free radical attack against lipids, proteins, sugars and nucleic acids leads to the formation of bioproducts whose detection in fluids and tissues represents the currently available method for assessing oxidative/nitrosative damage. Post-mortem …
Physical exercise as an epigenetic modulator: Eustress, the "positive stress" as an effector of gene expression.
2012
Physical exercise positively influences epigenetic mechanisms and improves health. Several issues remain unclear concerning the links between physical exercise and epigenetics. There is growing concern about the negative influence of excessive and persistent physical exercise on health. How an individual physically adapts to the prevailing environmental conditions might influence epigenetic mechanisms and modulate gene expression. In this article, we put forward the idea that physical exercise, especially long-term repetitive strenuous exercise, positively affects health, reduces the aging process, and decreases the incidence of cancer through induced stress and epigenetic mechanisms. We pr…
Impact of high-fat diet on antioxidant status, vascular wall thickening and cardiac function in adult female LDLR<sup>–/–</sup> mice
2012
International audience; Background: Western diet, rich in saturated fatty acids and cholesterol, is associated with increased cardiovascular risk. We thus investigated in female mice the influence of this diet on plasma antioxidant status, vascular wall thickening and cardiac function. Methods and Results: Adult female C57BL/6J wild type (WT) and LDLR–/– mice were fed a normal diet (ND) or a high-fat diet (HFD) for 17 weeks. HFD induced an increase in plasma lipids and vitamin C (Vit C) levels in both groups but at a much higher level in LDLR–/– and a decrease in plasma ascorbyl free radical levels to Vit C ratio (an endogenous oxidative stress index) in LDLR–/–. We only found a slight decr…
Accessibility of Protein-Bound Chlorophylls Probed by Dynamic Electron Polarization
2018
The possibility to probe the accessibility of sites of proteins represents an important point to explore their interactions with specific substrates in solution. The dynamic electron polarization of nitroxide radicals induced by excited triplet states of organic molecules is a phenomenon that is known to occur in aqueous solutions. The interaction within the radical-triplet pair causes a net emissive dynamic electron polarization of the nitroxide radical, that can be detected by means of time-resolved electron paramagnetic resonance (TR-EPR) spectroscopy. We have exploited this effect to prove the accessibility of chlorophylls bound to a protein, namely, the water-soluble chlorophyll protei…
Copolymerization of VDF and HFP in Supercritical Carbon Dioxide: Experimental Analysis of the Reaction Loci
2010
Free radical copolymerization reactions of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) were carried out in supercritical carbon dioxide at T=50 °C. When ammonium carboxylate perfluoropolyether surfactants were used, the formation of polymer particles was observed provided that HFP mole fraction in the feed was not larger than 0.30. Under these conditions, the effect of the total interphase area of the polymer phase, Ap, on the product propertieswas investigated by comparing experiments with largely different amounts of stabilizer, i.e., ranging from precipitation (smaller Ap) to dispersion (larger Ap) polymerization systems. We found that the copolymer molecular weight distribut…
Electron Spin Resonance (ESR) dosimetry for clinical radiation beams.
2016
In the last two decades the electron spin resonance (ESR) technique has been widely adopted for dosimetry of the radiation beams used in radiation therapy. In particular, alanine dosimtery is nowadays recognized as an international standard system for transfer dosimetry and for high doses. This is because among the various solid-state dosimeters the alanine ESR detectors present several advantages such as: tissue equivalence, linearity of its dose-response over a wide range, high stability of radiation induced free radicals, no destructive read-out procedure, no sample treatment before EPR signal measurement. In this presentation the main applications of ESR dosimetry for the characterizati…
Spin trapping as tool for investigating radiation induced free radicals in biologically active molecules
2017
Since from the second half of the last century the spin trapping has found wide applications in chemistry, biology and medicine [1]. Of particular interest are the studied of the free radicals induced in biologically active molecules, such as DNA and proteins, when they are exposed to ionizing radiation. Their characterization allows to investigate the radiation-induced primary processes inside living cells. Indeed, ionizing radiations produce many kinds of free radicals through direct action; radicals can be formed also by indirect actions. However, the direct detection of these radicals is hard to obtain as they have a too short lifetime and this makes difficult to record them by conventi…