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

Hormone replacement therapy: relation to homocysteine and prooxidant-antioxidant status in healthy postmenopausal women

Studies have consistently shown a lower cardiovascular risk in women who received postmenopausal hormone replacement therapy (HRT)

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

THE EFFECTS OF CEFTRIAXONE, TEICOPLANIN AND MEROPENEM ON THE HEMORHEOLOGICAL PARAMETERS

Objective: Microcirculatory blood flow is altered in sepsis. Changes in hemorheological parameters may contribute to the alterations in microcirculatory blood flow. This study was conducted to observe the effects of ceftriaxone, teicoplanin and meropenem, commonly used antimicrobial agents in sepsis, on hemorheological properties

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

The benefits of hormone replacement therapy on plasma and platelet antioxidant status and fatty acid composition in healthy postmenopausal women

Oxidative stress is suggested to play an important role in the pathogenesis of cardiovascular disease (CVD). Various hormone replacement therapy (HRT) protocols are used to reduce the CVD risk in postmenopausal women. Recent studies found that HRT lowers lipid levels and improves vascular endothelial function in postmenopausal women. In this study the effects of HRT on plasma and platelet membrane fatty acid composition and the oxidant-antioxidant system in postmenopausal women are investigated. Blood samples were obtained from 50 postmenopausal women. Before starting treatment, all participants underwent clinical, biochemical and hormonal screening procedures including gynecologic and physical breast examination. Then oral HRT (2mg estrodiol valerate+1mg cyproterone acetate) were given to all subjects for 1 year. Levels of malondialdehyde (MDA), total thiol (t-SH) and fatty acid contents, activities of glutathione-Stransferase (GST) and superoxide dismutase (SOD) were measured before and after treatment. Platelet membrane palmitic, stearic and oleic acid contents decreased (6.5%, 22.5% and 21.9% respectively) and linoleic and arachidonic acid contents increased (21.2% and 25.4% respectively) after HRT. Platelet MDA, GST and SOD levels were lower and t-SH content was higher than pre-treatment levels. These results indicate that hormone replacement therapy may affect platelet membrane fatty acid content and oxidant-antioxidant balance in postmenopausal women

Urinary glycosaminoglycan levels in patients with Graves' opthalmopathy: An effective parameter for the grading of ophthalmopathy

An increased accumulation of glycosaminoglycans (GAGs) in retrobulbar tissues has been reported in patients with Graves' ophthalmopathy (GO). We examined quantitative urinary GAGs excretion in patients with different grades of GO. 36 patients with Graves' disease were included in the study. They were classified according to their grade of ophthalmopathy: Grade 2 (n=14), Grade 3 (n=14) and Grade 4 (n=8). When GAG levels of patients with ophthalmopathy were compared to controls, a significant increase was observed in both Grade 3 and Grade 4 patients, whereas no significant difference was found in Grade 2 patients. These results show that urinary excretion of GAGs is a possible marker for the activity of Graves' ophthalmopathy. Determination of urinary level of GAGs is recommended as a simple laboratory method for estimating the grade of ophthalmopathy