Search results for "OXIDATIVE STRESS"

Acute methionine load‐induced hyperhomocysteinemia enhances platelet aggregation, thromboxane biosynthesis, and macrophage‐derived tissue factor acti…

1997

A moderate elevation of plasma homocysteine is a risk factor for atherosclerosis and arterial and veinous thrombosis. However, the mechanisms leading to vascular disorders are poorly understood because studies that have investigated the potential atherothrombogenicity of hyperhomocysteinemia in vivo are scarce. Using a rat model, we were the first to show that dietary folic acid deficiency, a major cause of basal hyperhomocysteinemia, is associated with enhanced macrophage-derived tissue factor and platelet activities. We proposed that an homocysteine-induced oxidative stress may account for this hypercoagulable state. To determine the true thrombogenicity of moderate hyperhomocysteinemia a…

Phosphodiesterase-4 inhibition improves corticosteroid insensitivity in pulmonary endothelial cells under oxidative stress.

2012

Several clinical studies have shown that smoking in asthmatics and chronic obstructive pulmonary disease patients is closely associated with corticosteroid refractoriness. In this work, we have analyzed glucocorticoid insensitivity in human pulmonary artery endothelial cells (HPAECs) under cigarette smoke extract (CSE) exposure as well as the possible additive effects of the combination therapy with a phosphodiesterase (PDE)-4 inhibitor. Interleukin (IL)-8 was measured in cell supernatants by ELISA. Histone deacetylase (HDAC), histone acetylase (HAT), and intracellular cAMP levels were measured by colorimetric assays and enzyme immunoassay, respectively. PDE4 isotypes and glucocorticoid rec…

CRP-induced levels of oxidative stress are higher in brain than aortic endothelial cells

2010

C-reactive protein (CRP) has been demonstrated to induce blood-brain barrier disruption (BBB) involving NAD(P)H-oxidase dependent oxidative stress. It is unclear why CRP affects the BBB and not other vascular beds following stroke. Therefore we examined CRP receptor and NAD(P)H-oxidase expression levels in bovine brain- (BEC) and aortic endothelial cells. Dichlorodihydrofluorescein measurements revealed significantly higher CRP-induced reactive oxygen species (ROS) levels in BEC. Protein expression of the CRP-receptors CD16, CD32 and of the NAD(P)H-oxidase subunit p22phox were also significantly higher in BEC. In conclusion BEC show a higher vulnerability to CRP due to increased levels of C…

Role of cytokines and oxidative stress in the pathophysiology of acute pancreatitis: therapeutical implications.

2002

Abstract Severe acute pancreatitis causes a high incidence of mortality due to the systemic inflammatory response syndrome leading to multiple organ failure. At present, there is no treatment against severe acute pancreatitis, other than supportive critical care. The relationship between pancreatic injury and the uncontrolled systemic response is not completely understood. Nevertheless, experimental and clinical evidences have shown that pro-inflammatory cytokines and oxidative stress are critically involved in the development of local and systemic complications associated with severe acute pancreatitis. Serum levels of pro-inflammatory cytokines, such as TNF-alpha and IL-1beta, increase du…

Oxidative stress and innate immunity status in chickens exposed to high dose of ascorbic acid

2013

The effects of high dose ascorbic acid (10 000 mg·kg–1 in the diet) and the transition metal on the presence of oxidative stress in the internal organs of growing chicks, as well as on the innate immune system status, were investigated. Supplementation with a high dose of ascorbic acid had pro-inflammatory effects on the intestinal mucosa, and lysozyme levels were decreased significantly in all organs studied. High-dose ascorbic acid caused an imbalance between prooxidative and antioxidative activities and was associated with the generation of semiquinone radicals. We observed that ascorbic acid increased iron and cadmium absorption. When a high dose of ascorbic acid was applied, elevated k…

Evaluation of oxidative stress in hypertensive patients with transplanted kidney

2005

Oxidative tissue damage after phacoemulsification: influence of ophthalmic viscosurgical devices.

2003

To quantify the oxidative tissue damage after phacoemulsification, correlate the damage to the energy applied, and investigate the influence of ophthalmic viscosurgical devices (OVDs).Department of Ophthalmology, University of Mainz, Mainz, Germany.The study comprised 130 eyes operated on by 1 surgeon using the same phacoemulsification machine. Some eyes received an OVD before phacoemulsification and some did not. Energy values were expressed as phaco time; that is, ultrasound (US) time (seconds) after conversion to 100% phaco power. Patients were grouped as follows: Group 1, phaco time less than 20 seconds and no OVD; Group 2, phaco time 20 to 40 seconds and no OVD; Group 3, phaco time mor…

Non-alcoholic fatty liver disease pathogenesis: The present and the future

2008

Non-alcoholic fatty liver disease is the clinical hepatic expression of metabolic syndrome. The prevalence of non-alcoholic fatty liver disease is around 20-30%, and with a rapid increase in the metabolic risk factors in the general population, non-alcoholic fatty liver disease has become the most common cause of liver disease worldwide. A fraction (20-30%) of non-alcoholic fatty liver disease patients develop a potentially progressive hepatic disorder, namely non-alcoholic steatohepatitis, leading to end-stage liver disease. The pathogenesis of non-alcoholic fatty liver disease is not entirely understood, and even if insulin resistance is a major pathogenetic key, many other factors are im…

Therapy with non-invasive ventilation in patients with obstructive sleep apnoea: effects on atherogenic lipoprotein phenotype.

2009

Patients with obstructive sleep apnoea are at increased risk of atherosclerotic morbidity and mortality. Abnormalities in lipid metabolism that occur in response to chronic intermittent hypoxia in patients with sleep-disordered breathing may increase the cardiovascular risk in an already susceptible population. Atherogenic lipoprotein phenotype and small, dense LDL have an independent predictive role for future cardio- and cerebro-vascular events in patients with the metabolic syndrome. Therefore, testing the hypothesis that therapy of obstructive sleep apnoea may reduce atherogenic lipoprotein phenotype might have significant clinical implications. We suggest that abolition of obstructive …

Effect of different antioxidants in experimental alcoholic optic neuropathy

2008

Purpose To establish the possible beneficial effects of three synthetic antioxidants: S-adenosil-L-methionine (SAMe), N-acetyl-L-cysteine (NAC) and Ebselen in optic nerve damage following chronic ethanol feeding in adult rats. Methods Twenty male Sprague-Dawley rats (five groups of four animals each) were fed a liquid, ethanol-containing diet with littermates given isocaloric amounts of ethanol-free diet serving as controls. Antioxidants were administered by dissolving them in the liquid diet at 0.4 mg/ml (SAMe), 0.163 mg/ml (NAC) and 5.33 mg/ml (Ebselen). After 6 weeks, optic nerves were obtained and parameters that are relevant for the modulation of oxidative stress, such as antioxidants …