Search results for "pero"
showing 10 items of 3365 documents
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…
Effects of Long-Term Nitroglycerin Treatment on Endothelial Nitric Oxide Synthase (NOS III) Gene Expression, NOS III–Mediated Superoxide Production, …
2000
Abstract —Long-term nitroglycerin (NTG) treatment has been shown to be associated with cross-tolerance to endothelium-dependent vasodilators. It may involve increased production of reactive oxygen species (such as superoxide, O 2 ·− ) that rapidly inactivate the nitric oxide (NO) released from the endothelial cells. It remains to be elucidated, however, whether long-term treatment with NTG alters the activity and expression of the endothelial NO synthase (NOS III) and whether this enzyme can contribute to O 2 ·− formation. We studied the influence of long-term NTG treatment on the expression of NOS III as assessed by RNase protection assay and Western blot. Tolerance was measured ex vivo i…
Islet beta-cell apoptosis triggered in vivo by interleukin-1beta is not related to the inducible nitric oxide synthase pathway: evidence for mitochon…
2003
IL-1beta is recognized as an effector cytokine contributing to islet beta-cell destruction during diabetes. We have previously shown in vitro that IL-1beta induces nitric oxide (NO) and beta-cell damage. Here, we show that IL-1beta administration in vivo to Wistar rats transiently increases manganese superoxide dismutase activity, whereas inducible NO synthase is not detected, and the levels of nitrate+nitrate do not change. Moreover, a significant decrease of mitochondrial aconitase, leading to a rise of hydroperoxides, and islet beta-cell apoptosis, involving caspase-3 and -8, is observed. Analysis of adhesion molecules in beta-cells showed that intercellular adhesion molecule-1 is highly…
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…
Guinea pig Kupffer cells can be activated in vitro to an enhanced superoxide response
1988
Summary In the preceding paper it was shown that Kupffer cells isolated by digestion of the liver and purified by centrifugal elutriation can be activated in vitro by lipopolysaccharide and muramyl dipeptide to an enhanced superoxide response upon zymosan phagocytosis. Lipopolysaccharide and muramyl dipeptide also led to a strongly increased prostaglandin E 2 release during the phagocytosis of zymosan. This activation was accompanied by an increased production of prostaglandin E 2 during the incubation with the stimuli. Prostaglandin E 2 synthesis was inhibited by the cyclooxygenase inhibitor indomethacin, reduced by dexamethasone, but only slightly decreased by the lipoxygenase inhibitor n…
Type 2 diabetes, dyslipidemia, and vascular risk: rationale and evidence for correcting the lipid imbalance.
2004
Type 2 diabetes is an important cardiovascular risk factor. A significant component of the risk associated with type 2 diabetes is thought to be because of its characteristic lipid "triad" profile of raised small dense low-density lipoprotein levels, lowered high-density lipoprotein, and elevated triglycerides (TGs). Trials of statins and fibrates have included substantial numbers of patients with diabetes and indicate that lipid lowering reduces cardiovascular event rates in these patients. However, statins alone do not always address all the lipid abnormalities of diabetes. Fibrates, which have low affinity for peroxisome proliferator-activated receptor alpha (PPARalpha), improve most asp…
PGC-1α: a master gene that is hard to master
2012
Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a transcriptional coactivator that favorably affects mitochondrial function. This concept is supported by an increasing amount of data including studies in PGC-1α gene-deleted mice, suggesting that PGC-1α is a rescue factor capable of boosting cell metabolism and promoting cell survival. However, this view has now been called into question by a recent study showing that adeno-associated virus-mediated PGC-1α overexpression causes overt cell degeneration in dopaminergic neurons. How is this to be understood, and can these seemingly conflicting findings tell us something about the role of PGC-1α in cell stress and in cont…
New approaches in the treatment of Adamantiades-Behçet's disease.
2005
Purpose of review To update clinicians on the recent advances in the treatment of Adamantiades-Behcet's disease. Recent findings Interferon-α-2a and infliximab have proved able to induce prompt remission in the vast majority of Adamantiades-Behcet's patients with DMARD-resistant uveoretinitis. Efficacy of interferon-α-2a has also been reported for mucocutaneous lesions, arthritis, and (more anecdotally) for neuro-Behcet, while results from small case series suggest that infliximab is beneficial for mucocutaneous lesions and (more anecdotally) for arthritis and gastro-intestinal manifestations. Two cases of neuro-Behcet treated with infliximab showed a complete resolution. Finally, in a rand…
Endotheliale Dysfunktion: Pathophysiologie, Diagnostik und prognostische Bedeutung
2008
The endothelium plays a crucial role in the regulation of vascular tone. Recent studies have indicated that endothelial dysfunction develops in the presence of cardiovascular risk factors such as hypertension, diabetes mellitus, hypercholesterolemia and in chronic smokers, as well as in patients with a family history of cardiovascular disease. It has now been established that endothelial dysfunction represents the first indicator of vascular damage. Endothelial function can be assessed in coronary and peripheral conductance and resistance vessels by means of invasive and noninvasive (ultrasound-guided) methods such as intracoronary infusion of acetylcholine, the endothelium-dependent vasodi…
Nitric Oxide Synthesis in Vascular Physiology and Pathophysiology
2015
Nitric oxide (NO) is produced by three NO synthase (NOS) isoforms: neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS). Under physiological conditions, vascular NO is produced by eNOS and nNOS, with both playing atheroprotective roles. Under pathological conditions, iNOS can be induced and eNOS may become uncoupled. iNOS produces a large amount of NO, induces vascular dysfunction, and promotes atherogenesis. Uncoupled eNOS generates superoxide instead of NO and contributes significantly to endothelial dysfunction and atherogenesis. Major mechanisms of eNOS uncoupling include depletion of tetrahydrobiopterin, an essential co-factor for the eNOS enzyme, and deficiency of L-a…