Search results for "cysteine"

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…

Hyperhomocysteinemia in hemodialysis patients: Is it a risk factor for cardiovascular disease?

2005

Elevated Expression of Liver γ-Cystathionase Is Required for the Maintenance of Lactation in Rats

1999

Liver gamma-cystathionase activity increases in rats during lactation; its inhibition due to propargylglycine is followed by a significant decrease in lactation. This is reversible by N-acetylcysteine administration. To study the role of liver gamma-cystathionase and the intertissue flux of glutathione during lactation, we used lactating and virgin rats fed liquid diets. Virgin rats were divided into two groups as follows: one group was fed daily a diet containing the same amount of protein that was consumed the previous day by lactating rats (high protein diet-fed rats); the other virgin group was fed the normal liquid diet (control). The expression and activity of liver gamma-cystathionas…

L-cysteine and glutathione metabolism are impaired in premature infants due to cystathionase deficiency.

1995

There are conflicting reports in the literature as to whether L-cysteine is an essential amino acid in premature infants as the result of the absence of hepatic cystathionase activity. To analyze the physiological importance of the cystathionase deficiency, we studied sulfur amino acid metabolism in human neonates of different gestational ages. Plasma cystathionine concentrations are higher in premature infants < or = 32 wk gestation (group 1) than in premature infants of 33-36 wk gestational age (group 2) or in full-term infants (group 3), whereas plasma cysteine concentrations are much lower in group 1 and 2 premature infants than in mature infants. Furthermore, erythrocytes from group 1 …

The deubiquitinating enzyme CYLD regulates the differentiation and maturation of thymic medullary epithelial cells.

2014

The cross talk between thymocytes and the thymic epithelium is critical for T-cell development and the establishment of central tolerance. Medullary thymic epithelial cells (mTECs) are located in the thymic medulla and mediate the elimination of self-reactive thymocytes, thereby preventing the onset of autoimmunity. Previous studies identified the deubiquitinating enzyme CYLD as a critical regulator of T-cell development by activating proximal T-cell receptor signaling during the transition of double-positive to single-positive thymocytes. Here we evaluated the impact of the naturally occurring short-splice variant of the cyld gene (sCYLD) on the development and maturation of mTECs. We foun…

Comparative cytoprotective effects of carbocysteine and fluticasone propionate in cigarette smoke extract-stimulated bronchial epithelial cells

2013

Cigarette smoke extracts (CSE) induce oxidative stress, an important feature in chronic obstructive pulmonary disease (COPD), and oxidative stress contributes to the poor clinical efficacy of corticosteroids in COPD patients. Carbocysteine, an antioxidant and mucolytic agent, is effec- tive in reducing the severity and the rate of exacerbations in COPD patients. The effects of carbocysteine on CSE-induced oxidative stress in bronchial epithelial cells as well as the comparison of these antioxidant effects of carbocysteine with those of fluticasone propionate are unknown. The present study was aimed to assess the effects of carbocysteine (10−4 M) in cell survival and intracellular reactive o…

Effect of oral glutathione on hepatic glutathione levels in rats and mice

1989

Administration of oral glutathione (GSH) increases hepatic GSH levels in fasted rats, in mice treated with GSH depletors such as diethyl maleate and in mice treated with high doses of paracetamol. An increase in hepatic GSH levels after administration of oral GSH does not occur in animals treated with buthionine sulphoximine, an inhibitor of GSH synthesis. Administration of oral GSH leads to an increase in the concentration of l-cysteine, a precursor of GSH, in portal blood plasma. Oral administration of l-methionine produced a significant decrease of hepatic ATP in fasted rats, but not in fed rats. Administration ofN−acetylcysteine or GSH did not affect the hepatic ATP levels. The results …

Liver specific deletion of CYLDexon7/8 induces severe biliary damage, fibrosis and increases hepatocarcinogenesis in mice

2012

Background & Aims CYLD is a tumor suppressor gene that is mutated in familial cylindromatosis, an autosomal dominant predisposition to tumors of skin appendages. Reduced CYLD expression has been observed in other tumor entities, including hepatocellular carcinoma. In the present study, we analyzed the role of CYLD in liver homeostasis and hepatocarcinogenesis in vivo . Methods Mice with liver-specific deletion of CYLDexon7/8 ( CYLD FF xAlbCre ) were generated. Liver tissues were histologically analyzed and oval cell activation was investigated. Hepatocarcinogenesis was induced by diethylnitrosamine/phenobarbital (DEN/PB). Microarray expression profiling of livers was performed in untreated …

Hyperhomocysteinemia and the methylene tetrahydrofolate reductase C677T mutation in splanchnic vein thrombosis

2010

Introduction: The role that hyperhomocysteinemia (HH) and the C677T mutation in 5,10-methylenetetrahydrofolate reductase (MTHFR) play in splanchnic vein thrombosis (SVT) remains unclear due to this unusual thrombotic location. Objective: To analyse the possible association of HH with the C677T mutation in the MTHFR gene in SVT. Material and methods: We determined homocysteine levels and the C677T MTHFR mutation, along with classical cardiovascular risk factors, in 48 patients with SVT (18 Budd-Chiari syndrome, 11 mesenteric vein thrombosis, 19 portal vein thrombosis) and 84 controls. Results: In the univariate analysis, patients with SVT showed statistically higher homocysteine levels (P = …

Cardiovascular Risk Factors - Association with Lower Extremity Versus Coronary Artery Disease

2021

Abstract Atherosclerosis is the main cause of lower extremity artery disease (LEAD) and coronary artery disease (CAD). These two arterial territories share the major cardiovascular risk factors: smoking, hypertension, dyslipidaemia and diabetes. Current guidelines draw attention to other possible risk factors: homocysteine level, inflammation markers (e.g. high-sensitive C reactive-protein (CRP), interleukin 6) and chronic kidney disease (CKD.) The objective of this study was to evaluate the cardiovascular risk factors strength association with LEAD and CAD on a study population of 203 patients. Our study concluded that smoking seems to be the most powerful risk factor for LEAD, especially …