Dietary restriction of amino acids other than methionine prevents oxidative damage during aging: Involvement of telomerase activity and telomere length

Aims: It has been suggested that variations in the proportions of some dietary amino acids can slow down aging. In this study, the influence of amino acids other than methionine on aging was investigated

Vitamin E and ATPases: Protection of ATPase activities by vitamin E supplementation in various tissues of hypercholesterolemic rats

It has been shown that the lipid composition of plasma membrane can be modified in vivo by dietary fat. It has also been observed that an increase in the cholesterol content of plasma membranes results in decreased activities of ATPases. In the present study, we evaluated the changes in the activities of ATPases from erythrocytes, hepatocytes, and kidney cortex caused by cholesterol-rich diet in rats and subsequently examined the role of vitamin E administration on the cholesterol-induced effects in these tissues. Administration of hypercholesterolemic diet to the rats for 4.5 months, significantly decreased membrane Na+-K+-ATPase and Ca+2-ATPase activities in comparison to the controls in all tissues studied, Vitamin E supplementation to the hypercholesterolemic rats led to a recovery in membrane ATPase activities

Thymosin alpha-1: Evidence for an antiatherogenic effect

In the present study, the effects of thymosin alpha(1) on lipid peroxidation were studied in an in vivo model of experimental hypercholesterolemia. In groups II-IV, rabbits were fed a high-cholesterol diet 2% (w/w) for 10 weeks. Thereafter, rabbits in group III were fed a normal diet for another 14 days and those in group IV were given a normal diet plus 25 mu g/kg thymosin alpha(1) intraperitoneally every other day for the same period. At the end of this period, plasma and erythrocyte lipid levels and susceptibility of erythrocytes to lipid peroxidation were determined in all groups. Hypercholesterolemic rabbits had high plasma and erythrocyte lipid peroxide (TBARS) levels compared to control animals fed a normal diet. Plasma and erythrocyte TEARS levels significantly decreased in the thymosin-alpha 1-injected rabbits. In thymosin-alpha(1)-treated animals (group IV), most of the lipid plaques were replaced by fibrous tissue. These findings suggest that thymosin alpha(1) may have some beneficial effects on the treatment of atherosclerosis by normalizing blood lipid levels and by substantially protecting endothelial cells against free radical injury

Plasma and erythrocyte lipid peroxidation in smokers

Smoking has been associated with the pathogenesis of many diseases and clinical conditions such as chronic obstructive lung disease, atherosclerosis and cancer. However, free-radical mediated lipid peroxidation has been associated with the pathogenesis of many diseases. Smokers, a group at high risk of cardiovascular disease, are exposed to large quantities of reactive free radicals present in gas and tar phases of tobacco smoke. In the present study, we studied the lipid composition, lipoproteins, lipid peroxides and glutathione in plasma and erythrocyte of smokers and nonsmokers

Modified risk associations of lipoproteins and apolipoproteins by chronic low-grade inflammation

Introduction: Lipoproteins and the apolipoproteins (apo) that they carry are major determinants of cardiovascular diseases (CVD) as well as metabolic, renal and inflammatory chronic disorders either directly or through mediation of risk factors. The notion that elevated low-density lipoprotein cholesterol (LDL-C) and apoB levels are related to the acquisition of CVD and, high-density lipoprotein cholesterol (HDL-C) and apoA-I indicate protection against CVD has been challenged in the past decade. Advanced age, adiposity, ethnicity or impaired glucose intolerance rendered autoimmune activation in an environment of pro-inflammatory state/oxidative stress and may disrupt the linear risk association between lipoproteins

Performance of automated urine analyzers using flow cytometric and digital image-based technology in routine urinalysis

The purpose of this study was to evaluate the analytical performances of Sysmex UF-5000 and Dirui FUS-200 and to compare the results with manual microscopy and between each other. Two hundred fifty urine samples were analyzed for evaluation. Mid-stream specimens were studied sequentially using Dirui FUS-200 and Sysmex UF-5000, and also with manual microscopy within one hour. The physical and chemical components of urinalysis, and sediment results were investigated. The precision results of the FUS-200 and UF-5000 for WBCs, RBCs, and ECs were acceptable. The both analyzers demonstrated good linearity (r > 0.97), with no carry-over. The comparisons of FUS-200 and UF-5000 with manual microscopy for RBCs, WBCs, and ECs on 250 samples exhibited good agreement with little bias (R > 0.780). Only, the moderate agreements were obtained for calcium oxalate for both analyzers (R = 0.512, and 0.648, respectively). The sensitivities of the FUS-200 and UF-5000 were 75.8% and 86.8%, with specificities of 92.3% and 87.8% for WBCs, for RBCs the sensitivities were 91.1%, and 84.4% with specificities of 82.2%, and 89.6% for both analyzers. Kappa values of the UF-5000 were higher than FUS-200 for WBCs, RBCs, ECs, and calcium oxalate. The FUS-200 and UF-5000 urine analyzers, are both accurate, very precise systems and can be safely used in clinical laboratories. However, due to the technological characteristics of the UF-5000 analyzer, its positive impacts on the morphologic recognition and enumeration of RBCs and WBCs should be taken into account, particularly in university hospital laboratories with high patient volumes

Oxidant and antioxidant systems in NIDDM patients: Influence of vitamin E supplementation

Free radical-mediated oxidative stress has been implicated in adverse tissue changes in a number of diseases. In view of the role of oxidative processes in non-insulin dependent diabetes mellitus (NIDDM), in this study, we investigated the oxidant and antioxidant status of plasma in patients with NIDDM and the effect of vitamin E (800 IU/day) supplementation on oxidative stress, antioxidant defense system, fructosamine levels and insulin action. Thirty controls and 40 NIDDM patients were studied. In controls and patients, plasma lipids, vitamin E, lipid peroxide, total thiols (t-SH), superoxide peroxidase (SOD) and glutathione peroxidase (GPx) were measured in the basal state and after vitamin E (800 IU/d) supplementation for a month. All lipids and lipid fractions in plasma were significantly decreased, whereas the HDL-C level was changed in diabetic patients supplemented with vitamin E when compared with baseline values. Vitamin E administration also significantly reduced fasting glucose and fructosamine levels, whereas increased significantly reduced fasting glucose and fructosamine levels, whereas increased significantly plasma C-peptide and insulin levels (p < 0.01, p < 0.001, respectively). Following vitamin E supplementation, TBARs levels were found to be significantly lower (p < 0.001) than the baseline value NIDDM patients are. On the other hand, activities of GPx and SOD were significantly higher (p < 0.001) than baseline values. A similar trend was observed for total thiols contents, but in this case, the increase was not significant. In conclusion, this study demonstrates that vitamin E improved beta-cell function and increased plasma insulin and C-peptide levels, possibly by inducing the antioxidant capacity of the organism and/or reducing the peripheral resistance in NIDDM. Long-term studies are needed to demonstrate the beneficial effects of vitamin E on treatment/prevention of NIDDM

Effect of chronic smoking on the rheological behaviour and lipid composition of erythrocytes

The rheological properties of blood have important effects on blood circulation. Chronic cigarette smoke is a generally accepted major cardiovascular risk factor, but the mechanisms by which it promotes ischaemic vascular diseases are not fully understood. The changes might contribute to an explanation of how chronic smoking alters the rheological behaviour of red blood cells and increases both plasma and blood viscosity in ischaemic vascular disease. We have now assessed 25 healthy controls and 25 chronic smokers for their erythrocyte deformability, plasma and blood viscosity and Htc, and also determined erythrocyte cholesterol, total and cholinated phospholipids. When we compared healthy controls with chronic smokers, erythrocyte deformability, plasma and blood viscosity and Htc were significantly different (P < 0.01, P < 0.001 respectively). Cigarette smoking caused significant changes in the erythrocyte cholesterol, total and cholinated phospholipid levels (P < 0.001). These results suggest that chronic smoking may increase the risk of ischaemic vascular disease by changing the rheological behaviour and composition of phospholipids in the erythrocytes. Med Sci Res 27:825-826 (C) 1999 Lippincott Williams & Wilkins

Effects of thymosin alpha-1 on erythrocyte lipid levels and erythrocyte membrane (Na+-K+)-ATPase activity in experimental hypercholesterolemia

Thymosin alpha-1 is an active polypeptide isolated from thymus. This polypeptide is widely used in the diagnosis and treatment of many diseases, especially immune diseases. In this present study, we examined the effects of thymosin alpha-1 on plasma and erythrocyte lipid levels and the changes in erythrocyte membrane (Na+, K+)ATPase activity in hypercholesterolemic rabbits. The erythrocyte lipid levels decreased, whereas the erythrocyte membrane (Na+, K+)ATPase activity increased significantly in these rabbits after thymosin alpha-1 injection. These findings suggest that thymosin alpha-1 is effective on both the lipid level and erythrocyte membrane (Na+, K+)ATPase activity