Early postoperative function of the heart after coronary artery bypass grafting is not predicted by myocardial necrosis and glutathione-associated oxidative stress

BACKGROUND: To investigate whether cardioplegia-related myocardial necrosis, lactate and glutathione release are predictive for early postoperative cardiac function after coronary artery bypass grafting (CABG). METHODS: Twelve patients with stabile angina scheduled for elective CABG were included. Myocardial release of troponin I (Tn I), creatine kinase MB isoenzyme mass (CK-MB), oxidized glutathione (GSSG) and lactate in blood were measured before cardioplegia, and up to 20 min thereafter. Cardiac function was assessed for 12 postoperative hours. RESULTS: Release of Tn I and CK-MB peaked at 20 min (-14.5+/-24.1 ng/ml and -23.9+/-30.6 ng/ml, respectively) and lactate at 1 min of reperfusion (-1.5+/-0.6 mmol/l). Significant GSSG release occurred at 5 min, with concomitant increase of glutathione redox ratio. The changes were not correlated to ischemic time. Cardiac index was increased after CPB and remained higher than preoperative value until the first postoperative morning. No correlations between postcardioplegic heart function and markers of tissue injury were found. CONCLUSIONS: The extent of myocardial reversible and irreversible injury does not predict early postoperative contractile function of the heart.     

Antioxidative probiotic fermented goats' milk decreases oxidative stress-mediated atherogenicity in human subjects

The increasing interest in a healthy diet is stimulating innovative development of novel scientific products in the food industry. The viable lactic acid bacteria in fermented milk products, such as yoghurt, have been associated with increased lactose tolerance, a well-balanced intestinal microflora, antimicrobial activity, stimulation of the immune system and antitumoural, anticholesterolaemic and antioxidative properties in human subjects. Recently, we have studied a human Lactobacillus spp. strain that possesses antioxidative activity. The aim of the present pilot study was to develop goats' milk fermented with the human antioxidative lactobacilli strain, Lactobacillus fermentum ME-3, and to test the effect of the fermented probiotic goats' milk on oxidative stress markers (including markers for atherosclerosis) in human blood and urine and on the gut microflora. Twenty-one healthy subjects were assigned to two treatment groups: goats' milk group and fermented goats' milk group (150 g/d) for a period of 21 d. Consumption of fermented goats' milk improved anti-atherogenicity in healthy subjects: it prolonged resistance of the lipoprotein fraction to oxidation, lowered levels of peroxidized lipoproteins, oxidized LDL, 8-isoprostanes and glutathione redox ratio, and enhanced total antioxidative activity. The consumption of fermented goats' milk also altered both the prevalence and proportion of lactic acid bacteria species in the gut microflora of the subjects. We conclude that the goats' milk fermented with our special antioxidative lactobacilli strain Lactobacillus fermentum ME-3 exhibits anti-atherogenic effects.     

Atomic layer deposition of superparamagnetic ruthenium-doped iron oxide thin film

Due to the several applications of biosensors, such as magnetic hyperthermia and magnetic resonance imaging, the use of superparamagnetic nanoparticles or thin films for preparing biosensors has increased greatly. We report herein on a strategy to fabricate a nanostructure composed of superparamagnetic thin films. Ruthenium-doped iron oxide thin films were deposited by using atomic layer deposition at 270 and 360 °C. FeCl₃ and Ru(EtCp)₂ were used as metal precursors and H₂O/O₂ as the oxygen precursor. Doping with ruthenium helps to lower the formation temperature of hematite (α-Fe₂O₃). Ruthenium content was changed from 0.42 at% up to 29.7 at%. Ru-doped films had a nano-crystallized structure of hematite with nanocrystal sizes from 4.4 up to 7.8 nm. Magnetization at room temperature was studied in iron oxide and Ru-doped iron oxide films. A new finding is a demonstration that in a Ru-doped iron oxide thin film superparamagnetic behavior of nanocrystalline materials (α-Fe₂O₃) is observed with the maximum magnetic coercive force H_c of 3 kOe. Increasing Ru content increased crystallite size of hematite and resulted in a lower blocking temperature.

In atomic layer deposited Ru-doped α-Fe₂O₃ thin films superparamagnetic behaviour of nanocrystallites is observed with the magnetic coercive force up to 3 kOe.     

Homocysteine and red blood cell glutathione as indices for middle-aged untreated essential hypertension patients

OBJECTIVE: Intracellular glutathione in its reduced state is a principal cellular biomolecule with antioxidant activity. Glutathione and homocysteine metabolism are closely associated. As both oxidative stress and hyperhomocystinemia are associated with hypertension, we assessed the relationships between these variables. DESIGN AND SETTING: An observation-based case-control study, performed at a university teaching hospital. PATIENTS: Middle-aged male patients with untreated uncomplicated essential hypertension (mean +/- standard deviation age 53.0 +/- 7.2 years, n = 48) before any treatment and controls with similar age distributions (age 51.6 +/- 5.5 years, n = 28) were evaluated. METHODS: In all subjects, the plasma levels of homocysteine, lipids, creatinine, protein, and glucose were measured. Reduced and oxidized glutathione and folic acid were measured from red blood cells (RBC). RESULTS: The hypertensive patients had decreased levels of red blood cell reduced glutathione (RBC-GSH) and increased levels of oxidized glutathione, which resulted in elevated ratio of oxidized/reduced glutathione as compared to controls (P < 0.001). Plasma homocysteine levels were significantly higher in the hypertensive patients versus the age-matched controls (P < 0.004). In the hypertensive patients, RBC-GSH correlated inversely with systolic blood pressure, serum creatinine, protein and RBC folic acid. No correlation was detected between RBC-GSH and homocysteine. In the controls, RBC-GSH correlated inversely with homocysteine, RBC folic acid and creatinine. According to multiple regression, in the hypertensive patients RBC-GSH was related to systolic blood pressure, hemoglobin, plasma homocysteine, creatinine and protein. Such a relationship was not detected for the controls. CONCLUSION: In untreated hypertensive patients both homocysteine and systolic blood pressure are associated with intracellular oxidative stress as determined by RBC-GSH.     

Lipoic acid prevents suppression of connective tissue proliferation in the rat liver induced by n-3 PUFAs. A pilot study

As previously shown, dietary n-3 polyunsaturated fatty acids (n-3 PUFAs) suppress connective tissue proliferation in the rat liver wound concurrent with an elevated level of lipid peroxidation. The present study was undertaken to investigate the influence of alpha-lipoic acid (LA), a natural anti-oxidant, on these effects of n-3 PUFAs. Rats were fed with a commercial pellet diet (control group) or with diets enriched with 10% of sunflower oil (n-6 group) or 10% of fish oil (n-3 group) for 8 weeks followed by addition of LA to the same diets for 10 days. Then a liver thermic wound was induced and the administration of LA was continued for 6 days. The proliferation of the connective tissue, the level of lipid peroxidation and their peroxidizability and the content of prostaglandins E2 and F2alpha were measured in the liver wounds. LA prevented the suppression of connective tissue proliferation in the healing wound induced by n-3 PUFAs, avoided the increase in peroxidation of lipids, reduced peroxidizability of lipids and modulated the decrease in PGE2 and PGF2alpha. The results indicate that dietary LA may prevent the suppression of liver wound healing induced by n-3 PUFAs.