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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The dynamics of free radical processes during the acute stage of ischemic stroke and their relationship with the clinical status of patients were studied. An enhanced extracellular generation of reactive oxygen species (ROS) by peripheral phagocytes was observed in severe stroke patients during the whole acute stage. This generation correlated positively with the size of infarct, the severity of neurological deficit and handicap and correlated negatively with the improvement of the neurological status of patients. An increase in the activity of two enzymes from the antioxidant defense mechanism, catalase and glutathione peroxidase, was registered during the whole acute phase of stroke, regardless of its severity. The concentration of lipid peroxidation products increased over time. Blood concentration of thiobarbituric acid-reactive material (TBARM) correlated positively with the size of infarct, the severity of neurological deficit and handicap. In conclusion, extracellular ROS generation by phagocytes and blood TBARM concentration could be used as indicators for stroke outcome.
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PMID:Dynamics of free radical processes in acute ischemic stroke: influence on neurological status and outcome. 1517 93

NaoXinQing (NXQ) is a patented and approved drug of Traditional Chinese Medicine that has been used for years for the treatment of syndrome of apoplexy, but the underlying mechanism remains unclear. The present study is designed to investigate the effects of NXQ on hydrogen peroxide (H(2)O(2))-induced cell damage in NG108-15 cells. Exposure to H(2)O(2) induces apoptosis-like cell injury. Preincubation of cells with NXQ alleviated H(2)O(2)-induced cell injury and apoptosis. This herb medicine also improves redox imbalance in cells under the exposure of H(2)O(2) as indicated by the attenuation in the reduction of activities of intracellular endogenous antioxidants, glutathione and glutathione peroxidase as well as catalase, and by the decrease in the leak of lactate dehydrogenase and the accumulation of malondialdehyde. These results indicate that NXQ significantly protects NG108-15 cells against H(2)O(2) challenge by improving redox imbalance and inhibiting apoptosis, which might represent mechanisms underlying its potential usage in the prevention and treatment of syndrome of apoplexy.
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PMID:NaoXinQing, an anti-stroke herbal medicine, reduces hydrogen peroxide-induced injury in NG108-15 cells. 1518 56

The brain is deficient in oxidative defense mechanisms and hence is at greater risk of damage mediated by reactive oxygen species (ROS) resulting in molecular and cellular dysfunction. Emerging evidence suggesting the activation of glutamate gated cation channels, may be another source of oxidative stress, leading to neuronal degeneration. Oxidative stress has been implicated in the development of neurodegenerative diseases like Parkinsonism, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, epileptic seizures, and stroke. Melatonin, the pineal hormone, acts as a direct free radical scavenger and indirect antioxidant. It is suggested that the increase in neurodegenerative diseases is attributable to a decrease in the levels of melatonin with age. Melatonin has been shown to either stimulate gene expression for the antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase) or to increase their activity. Additionally, it neutralizes hydoxyl radical, superoxide radical, peroxyl radical, peroxynitrite anion, singlet oxygen, hydrogen peroxide, nitric oxide, and hypochlorous acid. Unlike other antioxidants, melatonin can easily cross all morphophysiological barriers, e.g., the blood brain barrier, and enters cells and subcellular compartments. Though evidence are accumulating to suggest the potential of melatonin in neurodegenerative conditions, much information needs to be generated before the drug can find place in neurology clinics.
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PMID:Neuroprotective role of melatonin in oxidative stress vulnerable brain. 1526 48

We previously showed that sunlight-mimicking light induces genotoxic damage not only in skin but also even in lung, bone marrow, and peripheral blood of hairless mice. Moreover, light and smoke acted synergically in the respiratory tract. To clarify the mechanisms involved, we investigated by cDNA-arrays the expression of 746 toxicologically relevant genes in skin and lungs of mice exposed for 28 days to light and/or environmental cigarette smoke. Glutathione-S-transferase-Pi and catalase were overexpressed in the lungs of mice exposed to light only. Moreover, the light induced in skin the expression of genes involved in carcinogenesis, photoaging, and production of genotoxic and oxidizing derivatives traveling at a distance. Smoke induced the expression of multiple genes in both skin and lung, which reflect adaptive responses and mechanisms related to cancer and, possibly, to emphysema and stroke. As shown in mice exposed to both light and smoke, the light tended to increase smoke-induced gene expression in lungs, while smoke tended to attenuate light-induced gene expression in skin. The oral administration of the nonsteroidal anti-inflammatory drug sulindac inhibited the light-induced overexpression of cyclooxygenase-2 and oxidative stress-related genes in skin, and down-regulated smoke-induced genes involved in oxidative stress, removal of damaged proteins, inflammation, and immune response in lung. These results provide a mechanistic insight explaining the systemic alterations induced by both light and smoke in mouse skin and lungs.
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PMID:Alterations of gene expression in skin and lung of mice exposed to light and cigarette smoke. 1528 47

Erythrocyte membrane lipid peroxidation and consequent percentage hemolysis and related antioxidant enzymes viz., superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase were determined in 16 cases of hemorrhagic stroke and 30 cases of thrombotic stroke. The results obtained were compared with 50 age and sex matched controls. 12 thrombotic stroke patients who showed symptomatic recovery after medication were considered for follow up. Lipid peroxidation and percentage hemolysis in patients with thrombotic stroke and hemorrhagic stroke was significantly elevated when compared to controls. Glutathione reductase and superoxide dismutase levels were found to be significantly reduced in thrombotic stroke and hemorrhagic stroke respectively, when compared to healthy subjects. There was no significant difference in the other parameters when compared to controls. In post treatment thrombotic stoke, catalase and glutathione reductase levels increased significantly and oxidative hemolysis decreased compared to their pretreatment values. Thus, our results indicate considerable oxidative stress in stroke.
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PMID:Lipid peroxidation, hemolysis and antioxidant enzymes of erythrocytes in stroke. 1552 59

Production of reactive oxygen species (ROS) increased in diabetic patients and oxidative damage may contribute to the development of diabetic complications. Malondialdehyde is known as marker of the oxidative damage. Catalase is one of antioxidative factors involved in elimination of ROS In this study, the plasma level of lipid peroxides and plasma catalase activity in 315 patients with diabetes mellitus were assayed. We also included 114 non-diabetic healthy controls whose age, sex were matched to the diabetic patients. The plasma levels of lipid peroxides (LPO) were determined by spectrophotometric method modified by Satoh and Yagi. Lipid peroxidation was estimated by the plasma level of malondialdehyde (MDA). In controls mean value of plasma lipid peroxides was 1.329 +/- 0.118 nmol/ml. In diabetic patients with ischemic stroke MDA level was 2.919 +/- 0.182 nmol/l; p<0.001, and in patients without ischemic stroke the MDA level was 2.329 +/- 0.149 nmol/l; p<0.05; between diabetic patients with ischemic stroke and patients without ischemic stroke p<0.01. The high level of lipid peroxides might induce a self-maintained chronic process which, in time, might lead to the aggravation of the macro- and microangiopathy in diabetes. The plasma levels of catalase were determined by Goth's spectrophotometric method. In 114 healthy persons the mean value of plasma catalase (CAT) activity was 115.3 +/- 14.5 MU/l with less plasma catalase for females (108.7 +/- 12.4 MU/l) than for males (118.9 +/- 16.6 MU/l). Mean value of plasma CAT was (102.4 +/- 12.7 MU/l in patients with ischemic stroke, p<0.001 and 116.3 +/- 18.7 MU/l in patients without ischemic stroke, p<0.05); between diabetic patients with ischemic stroke and patients without ischemic stroke p<0.01. Our results revealed a decrease in plasma CAT activity in patients with diabetes mellitus and ischemic stroke as compared to patients with diabetes mellitus without ischemic stroke. We can conclude that in diabetic patients the decrease in plasma CAT activity is the consequence of oxidative modifications. These results suggest that diabetic patients have significantly increased oxidative damage.
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PMID:Lipid peroxidation and catalase in diabetes mellitus with and without ischemic stroke. 1552 32

Flavonoids from the leaves of Diospyros kaki L (FLDK-P70) are main therapeutic components of NaoXingQing, which is a novel and patented Traditional Chinese Medicine drug used for the treatment of syndrome of apoplexy for years in China. The present study investigated the effects of FLDK-P70 on hydrogen peroxide (H2O2)-induced apoptosis-like damage of NG108-15 cells. Pretreatment of cells with FLDK-P70 alleviated H2O2-induced cell injury and apoptosis by upregulating Bcl-2 expression and improving redox imbalance as indicated by the alleviation of the decline in the intracellular endogenous antioxidants: glutathione and glutathione peroxidase as well as catalase, with the decrease of the leak of lactate dehydrogenase and the reduction of the accumulation of malondialdehyde. These results indicate that FLDK-P70 may be potentially used in the prevention and treatment of ischemia/reperfusion injury and other neurodegenerative disease. Upregulating bcl-2 and improving cellular redox state by FLDK-P70 may play critical roles in attenuating oxidative injury.
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PMID:Flavonoids from the leaves of Diospyros kaki reduce hydrogen peroxide-induced injury of NG108-15 cells. 1570 80

We present the results of the first theoretical investigation of salen-manganese complexes as synthetic catalytic scavengers of hydrogen peroxide molecules that mimic catalase enzymes. Catalase mimics can be used as therapeutic agents against oxidative stress in treatment of many diseases, including Alzheimer's disease, stroke, heart disease, aging, and cancer. A ping-pong mechanism approach has been considered to describe the H2O2 dismutation reaction. The real compounds reacting with a peroxide molecule were utilized in our BP density functional calculations to avoid uncertainties connected with using incomplete models. Part I of the dismutation reaction-converting a peroxide molecule into a water molecule with simultaneous oxidation of the metal atom of the catalyst-can be done quite effectively at the Mn catalytic center. To act as catalytic scavengers of hydrogen peroxide, the oxomanganese salen complexes have to be deoxidized during part II of the dismutation reaction. It has been shown that there are two possible reaction routes for the second part of the dismutation reaction: the top and the side substrate approach routes. Our results suggest that the catalyst could be at least temporarily deactivated (poisoned) in the side approach reaction route due to the formation of a kinetically stable intermediate. Overall, the side approach reaction route for the catalyst recovery is the bottleneck for the whole dismutation process. On the basis of the detailed knowledge of the mode of action of the (salen)MnIII catalase mimics, we suggest and rationalize structural changes of the catalyst that should lead to better therapeutic properties. The available experimental data support our conclusions. Our findings on the reaction dismutation mechanism could be the starting point for further improvement of salen-manganese complexes as synthetic catalytic scavengers of reactive oxygen species.
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PMID:(salen)MnIII compounds as nonpeptidyl mimics of catalase. Mechanism-based tuning of catalase activity: a theoretical study. 1573 83

Korean ginseng tea (KGT), prepared from the roots of Panax ginseng, is widely used by Korean people for antistress, antifatigue, and endurance promoting effects. In the present study we evaluated neuroprotective/cerebroprotective actions of KGT in stroke, using rat global and focal models of ischemia. Varied biochemical/enzymatic alterations, produced subsequent to the application of middle cerebral artery (MCAO) and bilateral carotid artery occlusion (BCAO) followed by reperfusion viz. increase in lipid peroxidation (LPO) and decrease in glutathione (GSH), glutathione reductase (GR), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GPx) and superoxide dismutase (SOD), were markedly reversed and restored to near normal levels in the groups pre-treated with KGT (350 mg/kg given orally for 10 days). It is concluded that the protective action, exhibited by KGT against hypoperfusion/reperfusion induced brain injury, suggests its therapeutic potential in cerebrovascular diseases (CVD) including stroke. These findings are important because: (a) the present treatment strategies for CVD are far from adequate and (b) KGT with wide usage is known to be a safe natural product.
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PMID:Cerebroprotective effect of Korean ginseng tea against global and focal models of ischemia in rats. 1597 Apr 12

The study of oxidative contributions to aging has reached sufficient maturity to support the development of interventional strategies designed to forestall or reverse protein cross-linking, oxidation of DNA and lipids, and mitochondrial senescence associated with chronic pathology and aging. Catalytic antioxidants, including combined superoxide dismutase (SOD) and catalase mimics, extend the lifespan of oxidatively compromised animals such as Mn-SOD knockout mice, and will be entering the clinic for radiation-induced dermatitis. Substituted phenacylthiozolium compounds that slow the formation and break extant protein cross-linkages formed via Maillard reactions, restoring vascular compliance in aged animals, and are showing efficacy in clinical trials. Non-feminizing estrogen analogs (eg, 17- alpha estradiol) block cytotoxicity in a host of oxidative stress models and moderate neuronal loss in MCAO stroke models. Efficacy of the polycyclic phenols is synergistically amplified by glutathione supplementation, suggesting that the two function as a redox couple analogous to vitamin E and ascorbate. Finally, discovery of novel small molecules designed to stabilize mitochondrial function during Ca(2+)-induced oxidative stress, such as that occurring during stroke or myocardial ischemia reperfusion, will be accelerated by a proprietary fluorescence resonance energy transfer assay developed at MitoKor. Maintaining mitochondrial function under these circumstances will improve cellular bioenergetic and oxidative status, and hence moderate secondary necrosis and apoptosis.
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PMID:Oxidative Stress and Aging - Second International Conference. Technologies for assessment and intervention strategies. 2-5 April 2001, Maui, USA. 1599 30


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