Search results for "Dative"
showing 10 items of 2381 documents
Vitamin E Paradox in Alzheimer's Disease: It Does Not Prevent Loss of Cognition and May Even Be Detrimental
2009
There is controversy as to whether vitamin E is beneficial in Alzheimer's disease (AD). In this study, we tested if vitamin E prevents oxidative stress and loss of cognition in AD. Fifty-seven AD patients were recruited and divided in two groups: placebo or treated with 800 IU of vitamin E per day for six months. Of these 57 patients, only 33 finished the study. We measured blood oxidized glutathione (GSSG) and used the following cognitive tests: Mini-Mental State Examination, Blessed-Dementia Scale, and Clock Drawing Test. Of those patients treated with vitamin E, we found two groups. In the first group, "respondents" to vitamin E, GSSG levels were lower after the treatment and scores on t…
Prevention of apoptosis by deferoxamine during 4 hours of cold cardioplegia and reperfusion: in vitro study of isolated working rat heart model.
2002
INTRODUCTION: Heart transplantation is often accompanied by multiple functional alterations, especially in reperfusion period. These are probably related to the reactive oxygen species (ROS) formation catalyzed by transition metals such as iron and copper, and thus the preservation time of the donor hearts is limited. Metabolic protection of the heart grafts is a permanent objective of numerous experiments. Recently, an iron chelator deferoxamine (DFX) was proposed as antioxidant agent for storage solutions in heart grafts. Oxidative stress is also known to mediate the apoptotic cell death in different tissues during ischemia-reperfusion. METHODS: The aim of this study was to evaluate a pos…
Effect of a Diet Supplemented with alpha-Tocopherol and beta-Carotene on ATP and Antioxidant Levels after Hepatic Ischemia-Reperfusion.
2008
Ischemia-reperfusion injury associated with liver transplantation remains a serious complication in clinical practice. In the present study the effect of intake of alpha-tocopherol or beta-carotene to limit liver injury by oxidative stress in ischemia and reperfusion was explored. Wistar rats were fed with diets enriched with alpha-tocopherol (20 mg/day) or beta-carotene (3 mg/day) for 21 days. After 21 days, their livers were subjected to 15 and 30 min of ischemia and afterwards were reperfused for 60 min. The recovery of levels of ATP during reperfusion was better in the group of rats whose diets were supplemented with alpha-tocopherol or beta-carotene than in the group control. The suppl…
Evaluation of the Possible Contribution of Antioxidants Administration in Metabolic Syndrome
2011
The metabolic syndrome (MetS) is common, and its associated risk burdens of diabetes and cardiovascular disease (CVD) are a major public health problem. The hypothesis that main constituent parameters of the MetS share common pathophysiologic mechanisms provides a conceptual framework for the future research. Exercise and weight loss can prevent insulin resistance and reduce the risk of diseases associated with the MetS. Interrupting intracellular and extracellular reactive oxygen species (ROS) overproduction could also contribute to normalizing the activation of metabolic pathways leading to the onset of diabetes, endothelial dysfunction, and cardiovascular (CV) complications. On the other…
Redox modulation of mitochondriogenesis in exercise. Does antioxidant supplementation blunt the benefits of exercise training?
2015
Physical exercise increases the cellular production of reactive oxygen species (ROS) in muscle, liver, and other organs. This is unlikely due to increased mitochondrial production but rather to extramitochondrial sources such as NADPH oxidase or xanthine oxidase. We have reported a xanthine oxidase-mediated increase in ROS production in many experimental models from isolated cells to humans. Originally, ROS were considered as detrimental and thus as a likely cause of cell damage associated with exhaustion. In the past decade, evidence showing that ROS act as signals has been gathered and thus the idea that antioxidant supplementation in exercise is always recommendable has proved incorrect.…
Biochemical adaptations in middle-distance runners: an assessment of blood and anthropometric parameters
2014
In order to understand the mechanism underlying the physiological adaptation of purely aerobic workout, we investigated the effect of 2 months of training on nine males (17-22 year-old) middle distance running agonistic athletes. Blood sample was collected in the morning to analyze: hematological parameters, lipid profile, liver function enzymes [glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, gamma-glutamyl transferase (γ-GT)] and skeletal and myocardial markers of muscle damage [creatin kinase (CK) and creatin kinase MB (CK-MB)]. Endurance training, as it implies high oxygen consumption, should increase reactive oxygen species, but it has been shown that exercise lea…
Oxidative stress in vascular disease and its pharmacological prevention
2013
Cardiovascular risk factors lead to enhanced production of reactive oxygen species (ROS) generated by NADPH oxidase, xanthine oxidase (XO), the mitochondrial electron-transport chain (ETC), and dysfunctional endothelial nitric oxide synthase (eNOS). When the capacity of antioxidant defense systems [e.g., superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), heme oxygenase (HO), paraoxonase (PON)] is exceeded, this results in oxidative stress, which can promote atherogenesis. Therefore, pharmacological means to prevent oxidative stress are of major therapeutic interest. Some established drugs and novel therapeutic approaches can prevent oxidative stress and, presumably, vascula…
Overexpression of G6PD as a model of robustness
2018
Introduction Frailty is a major geriatric syndrome that has been associated to oxidative stress. The antioxidant system is largely based on the reducing power of NADPH, whose levels are mainly determined by the enzyme glucose-6-phosphate dehydrogenase (G6PD). Material and methods Using old female Tg-mice overexpressing G6PD (18 to 26 months old), we measured frailty and different muscle parameters: oxidative stress, cross-sectional area (CSA), markers regulating protein synthesis, mitochondrial dynamics, and apoptosis. Results Our results show that 18–24 months old G6PD-Tg animals performed better in the motor coordination and grip strength test than the WT. We also found lower changes in b…
Clinical and Molecular-Genetic Insights into the Role of Oxidative Stress in Diabetic Retinopathy: Antioxidant Strategies and Future Avenues
2020
Reactive oxygen species (ROS) overproduction and ROS-signaling pathways activation attack the eyes. We evaluated the oxidative stress (OS) and the effects of a daily, core nutritional supplement regimen containing antioxidants and omega 3 fatty acids (A/ω3) in type 2 diabetics (T2DM). A case-control study was carried out in 480 participants [287 T2DM patients with (+)/without (−) diabetic retinopathy (DR) and 193 healthy controls (CG)], randomly assigned to a daily pill of A/ω3. Periodic evaluation through 38 months allowed to outline patient characteristics, DR features, and classic/OS blood parameters. Statistics were performed by the SPSS 24.0 program. Diabetics displayed significantly h…
Arginine and nitric oxide synthase: regulatory mechanisms and cardiovascular aspects
2014
L-Arginine (L-Arg) is a conditionally essential amino acid in the human diet. The most common dietary sources of L-Arg are meat, poultry and fish. L-Arg is the precursor for the synthesis of nitric oxide (NO); a key signaling molecule via NO synthase (NOS). Endogenous NOS inhibitors such as asymmetric-dimethyl-L-Arg inhibit NO synthesis in vivo by competing with L-Arg at the active site of NOS. In addition, NOS possesses the ability to be "uncoupled" to produce superoxide anion instead of NO. Reduced NO bioavailability may play an essential role in cardiovascular pathologies and metabolic diseases. L-Arg deficiency syndromes in humans involve endothelial inflammation and immune dysfunctions…