Effect of methoxy polyethylene glycol-epoetin beta on oxidative stress in predialysis patients with chronic kidney disease.

BACKGROUND: There is data in the literature indicating increased oxidative stress in chronic kidney disease (CKD). Erythropoiesisstimulating agents (ESAs), which are commonly used to treat anemia in patients with CKD, seem to have an antioxidant action, which could be a part of nephroprotection. The aim of the current study was to investigate the effect of a long half-life ESA, methoxy polyethylene glycol-epoetin beta (Mircera), on some markers of oxidative stress in predialysis patients with CKD. MATERIAL AND METHODS: Peripheral blood was collected from 28 predialysis CKD patients 2 times, before Mircera treatment and after achieving target hemoglobin (Hb), and 15 healthy subjects (control group). Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activity in erythrocytes were measured according to commonly used methods as a function of the antioxidant defense system. To assess reactive oxygen species (ROS) production, malondialdehyde (MDA) concentration in erythrocytes and in plasma was measured according to a commonly used method. RESULTS: SOD, GSH-Px, and CAT activity were similar, but plasma and erythrocyte MDA concentrations were significantly higher in CKD patients before ESA treatment in comparison to the control group. SOD, GSH-Px, and CAT activity was significantly higher, but plasma and erythrocyte MDA concentrations were significantly lower, in CKD patients after ESA treatment in comparison to these patients before treatment. We did not find a significant correlation between Hb concentration and SOD, GSH-Px, and CAT activity and plasma, as well as erythrocyte MDA concentrations. Analysis of all investigated groups showed a significant negative correlation between Hb concentration and plasma MDA concentration. CONCLUSIONS: Our results suggest that treatment of anemia with methoxy polyethylene glycol-epoetin beta may inhibit oxidative stress in predialysis patients with CKD by enhancing the antioxidant defense system and reducing ROS production.

[Estimation of selected parameters antioxidant barrier and lipid parameters in children with atherosclerosis risk factors]. / Ocena wybranych parametrów bariery antyoksydacyjnej i przemiany lipidowej u dzieci ze stwierdzonymi czynnikami ryzyka miazdzycy.

UNLABELLED: Atherosclerosis is one of the most common causes of mortality in developed countries. One of the many factors in its etiopathogenesis are reactive oxygen species (ROS), excess of which comes from disturbances of enzymatic and nonenzymatic mechanisms of antioxidant barrier. THE AIM OF THIS STUDY was to estimate relations between the activity of chosen parameters antioxidant barrier and the lipid levels in children with atherosclerosis risk factors. MATERIAL AND METHODS: The study was carried out on 48 children with atherosclerosis risk factors. The control group consisted of 25 healthy children. Total cholesterol (TC), Triglycerides (TG), HDL-C, LDL-C were determined by enzymatic method. The activity of superoxide dismutase (SOD) was estimated by Misra and Fridivich's method, glutathione peroxidase (GSH-Px) with method proposed by Sedlak and Lindsay in modyfication Little and Brien and the activity o catalase (CAT) by Beer and Sizer's method. Malonyl dialdehyde (MDA) concentration was determined by Placer's method. RESULTS: Obesity, lipid disorders, and hypertension were the most frequent risk factors in the investigated children. Statistically significant higher concentration of TC, LDL-C, TG and lower HDL-C were observed in children with atherosclerosis risk factors. Activity of glutathion peroxidase was statistically significant higher in children with atherosclerosis risk factors (p < 0.001), activity of catalase was lower (p < 0.05). No significant differences in activity of superoxide dismutase and malonyl dialdehyde were observed in the investigated groups. CONCLUSION: Modificated activity of selected antioxidants in children with atherosclerosis risk factors could determine an index of antioxidant barrier and might potencially constitute the marker of early atherosclerotical risk development.

[Antioxidative defense and level of microelements in youth with hypertension]. / Status antyoksydacyjny a stezenie pierwiastków sladowych u mlodziezy z podwyzszonym cisnieniem tetniczym.

UNLABELLED: In recent years we observed increased interest of free radical processes accompanying varying physiological and pathological reactions. THE AIM OF THIS STUDY was an evaluation some of serum microelements (zinc, manganium, chromium, selenium) in serum and antioxidative defense in youth with hypertension. MATERIAL AND METHODS: The group of 88 youth aged 9-18 with normal blood pressure, prehypertension and hypertension was examined. Blood was taken to examine microelements content and antioxidative barrier activity. Microelements content was estimated with the method ICP-AES. Superoxide dismuthase activity in red blood cells was estimate with the method by Misra and Fridovich, glutatione peroxidase activity with the method by Sedlak and Lindsay in modification by Little and O'Brien and catalase activity with the method of Beers and Sizer. RESULTS: In subgroup with higher blood pressure we observed decreased tendency in enzymatic antioxidant activity (Cat, GSA-Px, SOD) in red blood cells and lowering levels of vitamins C and E in comparison to persons with normal blood pressure. Concentrations of estimated microelements drowed decreased levels in persons with hypertension. CONCLUSIONS: Results of our study suggest that disturbance in pro - and anti-oxidative balance observed in youth with first state of hypertension may play an important role in pathogenesis of hypertension.

[Assessment of malonyldialdehyde concentration as a product of lipid peroxidation and lipid metabolism in patients on chronic dialysis]. / Ocena stezenia malonylodialdehydu jako produktu peroksydacji lipidów a gospodarka lipidowa u chorych przewlekle dializowanych.

UNLABELLED: Chronic hemodialysis in patients with renal insufficiency is a factor significantly intensifying oxidative stress, resulting in increased lipid and lipoprotein peroxidation. It intensifies atherosclerotic activity. Malonyldialdehyde (MDA) concentration in serum, and isolated fraction of low density lipoprotein is indicators of lipid peroxidation intensification and therefore arteriosclerosis development. THE AIM OF THE STUDY: Assessment of MDA concentration as a product of lipid peroxidation and lipid metabolism in patients on chronic dialysis. MATERIALS AND METHODS: The study included 48 dialyzed patients, age 22-68 undergoing chronic dialysis for, on average, 56 months. On account of dialysis period the patients were included into 3 subgroups: group 1 (n = 17) dialysis period 2 years, group 2 (n = 13) dialysis period 2-5 years and group 3 (n = 18) dialysis period longer than 5 years. Control group consisted of 30 healthy subjects. We assessed: malonyldialdehyde in serum and isolated fraction of low density lipids (LDL) and high density lipid (HDL) and cholesterol (CH) and triglycerides (TG), phospholipids (PL) in serum and isolated lipoprotein fractions. RESULTS: Significantly decreased levels of HDL, LDL fractions and increased triglicerides and elevated levels of MDA in serum and isolated LDL fraction were found in patients on chronic dialysis in comparison to control group (p < 0.05). CONCLUSION: Our results indicate apparent normalization of lipid metabolism in patients on chronic dialysis and suggest that MDA assessment is better marker for arteriosclerosis risk estimation in long-term dialyzed patients.

[Nitric oxide metabolism]. / Metabolizm tlenku azotu.

Nitric oxide is an important mediator of physiological and pathological processes. It is a lipophilic molecule that contains a single unpaired electron which causes NO to be chemically reactive, and to function as a free radical with a short lifetime. NO can act by direct and indirect effects. Direct effects occur between NO and specific biological molecules whereas indirect effects are mediated by reactive nitrogen oxide species (RNOS) formed from the reaction of NO either with oxygen or superoxide. This review discusses the metabolic pathways of NO.

[The influence of selected nonsteroidal anti-inflammatory drugs on antioxidative enzymes activity]. / Wplyw wybranych niesteroidowych leków przeciwzapalnych na aktywnosc enzymów antyoksydacyjnych.

Three nonsteroidal anti-inflammatory drugs were tested: two inhibitors of COX-1 and COX-2 (acetylosalicylic acid and diclofenac), one inhibitor of COX-2 (nimesulid) and superoxide dismutase, catalase and glutatione peroxidase activity was estimated. The investigations were carried out in rats fed by gastric tube for three weeks with acetylsalicylic acid in doses of 2 and 10 mg/kg body weight, diclofenac in doses 1 and 5 mg/kg body weight and nimesulid in doses 2.5 and 12.5 mg/kg body weight. The results were compared with a control group of rats which obtained water into the stomach. No statistically characteristic changes of superoxide dismutase activity were observed. Catalase activity was statistically decreased after both doses of nimesulid and acetylsalicylic acid at the dose of 10 mg/kg body weight. Both doses of diclofenac increased catalase activity. Glutatione peroxidase activity was statistically decreased after both doses of nimesulid and in the dose 10 mg/kg body weight of acetylsalicylic acid and in the dose 5 mg/kg body weight of diclofenac.

[Assessment of 8-hydroxy-2'-deoxyguanosine concentrations in bladder cancer patients treated with intravesical BCG instillation]. / Analiza stezenia 8-hydroksy-2'-deoxyguanozyny w moczu chorych na powierzchownego raka pecherza moczowego leczonych zawiesina pratka BCG.

UNLABELLED: Increased 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentration has been proposed as reliable marker of the oxidative DNA damage, and prognostication of urological carcinogenesis, particularly in bladder cancer. Widely accepted method of treatment in early stages of bladder cancer is transurethral electro resection (TURN). Intravesical bacillus Calmette-Guerin instillation is considered to be the therapeutic agent for superficial transitional cell carcinoma (TCC) of the bladder and has been established as standard therapy in the patients. The aim of the study was to test the concentration of 8-OHdG in urine in patients with bladder cancer and the effect of TURN and BCG therapy on the 8-OHdG value. MATERIAL AND METHODS: We tested 12 patients (3 female and 9 male) with superficial bladder cancer and 31 healthy controls. Urine for the examination was drawn in 4 time points: before and 2 weeks after TURN treatment, then 6 weeks after 6 intravesical instillations of BCG (Onko BCG--BIO MED Lublin) by Morales and 12 weeks after TURN. 8-OHdG concentration in urine was tested using ELISA commercial kit (OXIS health) and the values of 8-OHdG are expressed as ng/ml of urine. RESULTS: Patients with superficial bladder cancer had 16.89 ng/ml of 8-OHdG in urine before the TURN procedure. The value was significantly (p< 0.005) higher then 12.98 ng/ml noted in healthy controls. 2 weeks after the procedure the 8-OHdG level decreased to 13.36 ng/ml. After 6 weeks of repeated 6 intravesical instillations of the BCG the concentration of 8-OHdG dropped to 10.91 ng/ml (p<0.005) and returned to the value 13.28 ng/ml after the next 4 weeks. CONCLUSIONS: Patients with bladder cancer have significantly increased concentration of 8-OHdG in urine compared to controls. 8 week combine therapy with TURN and BCG resulted in a significant decrease in 8-OHdG concentration in urine The beneficial effect of BCG instillations seems to result from strengthening of the antioxidative DNA protection.

[The use of anthocyanins in the treatment of cardiovascular diseases]. / Wykorzystanie antocyjanin w terapii chorób ukladu sercowo-naczyniowego.

Anthocyanins are common ingredients of human diet, and the rich source of them are: aronia fruits, black currant, raspberry, grapes and apples. Because of their chemical structure they are able to influence many active substances in human body having antioxidative, antiinflammatory and cardioprotective activity.

[Nitric oxide--oxidant or antioxidant?]. / Tlenek azotu--oksydant czy antyoksydant?

Nitric oxide (NO), as a free radical, seems to be a potential antioxidant. It takes part in termination of lipid peroxidation reactions. It can be also an oxidant, particularly in indirect reactions with oxygen molecules or superoxide anion.

[The influence of anthocyanins from Aronia melanocarpa on selected parameters of oxidative stress and microelements contents in men with hypercholesterolemia]. / Wplyw antocyjanin z aronii czarnoowocowej na wybrane parametry stresu oksydacyjnego i zawartosc mikroelementów u mezczyzn z hipercholesterolemia.

THE AIM OF THE STUDY: Our investigations was to estimate the influence of Aronia anthocyanins (Aronox by Agropharm) on selected parameters of oxidative and antioxidative balance as well as on the concentration of selected metals in red blood cells in men with hipercholesterolaemia. MATERIAL AND METHODS: 16 men aged 27 +/- 6.4 years old with blood cholesterol concentration on the level of 205-250 mg/dl took 240 mg of anthocyanins a day for 30 days. Before and after the period of anthocyanins administration a blood sample was taken and following parameters were estimated: lead, aluminium, cooper and zinc concentration in erythrocytes with the method of atomic emission spectrometry with induced coupling plasma (AES-ICP), concentration of substances reacting with thiobarbituric acid (TBARS) and superoxide dismutase, glutathione peroxidase and catalase activities in hemolysate. CONCLUSION: 30 days long administration of 240 mg of anthocyanins a day, caused a substantial increase of glutathione peroxidase and catalase activities. The lead, aluminium and cooper concentration was decreased while zinc concentration in red blood cells was increased.

[Effect of hyperthyreosis on the concentration of antioxidative vitamins and microelements]. / Wplyw hipertyreozy na zawartosc antyoksydacyjnych witamin i mikroelementów.

In the course of hyperthyreosis reactive oxygen production increases and oxidative stress develops. The consequences of oxidative stress comprise disturbances in balance of pro- and antioxidative agents, including changes in concentration of antioxidative vitamins and microelements. Although the results of published studies concerning changes of concentrations of vitamins and microelements in hyperthyreosis are contradictory, most frequently a decrease of zinc and magnesium concentrations was observed.

Effect of anthocyanins on selected biochemical parameters in rats exposed to cadmium.

Cadmium is a dangerous occupational and environmental toxin. It accumulates in the human organism mainly in liver and kidneys. Cadmium half-life is about 10 years, so the symptoms of cadmium intoxication may occur several years after the exposure. Until now in treating intoxication with this metal chelating compounds have been used, burdened with numerous undesirable symptoms. In our investigations anthocyanins from Aronia melanocarpa were used to reduce the harmful results caused by cadmium. Administering anthocyanins with cadmium chloride resulted in a statistically significant decrease of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity, concentration of bilirubin and urea in blood serum and decreased cadmium cumulation in liver and kidneys in relation to animals receiving cadmium chloride only.

[Effect of ethylene glycol on antioxidative enzymes and lipid peroxidation activity in erythrocytes]. / Wplyw glikolu etylenowego na aktywnosc enzymów antyoksydacyjnych i peroksydacje lipidów w erytrocytach.

Investigations were aimed at demonstrating changes in the activity of enzymes forming an antioxidative barrier and oxidative stress parameters in erythrocytes of rats which were administrated ethylene glycol during 4 weeks. Superoxide dismutase activity (CuZn-SOD) was evaluated by the Misra and Fridovich method, catalase (EC1.11.1.6.) by the Beers and Sizer method and malonyl dialdehyde concentration (MDA) with Placer et all were assessed in the obtained material through the evaluation of TBARS compounds concentration. In the 4th week of the experiment a decrease in catalase (9.3 U/gHb to 5.7 U/gHb) and superoxide dismutase (2378 U/gHb to 1759 U/gHb) activity was observed. Malonyl dialdehyde concentration increased from the initial 0.14 mumol/gHb to 0.24 mumol/gHb. The investigations carried out have demonstrated that long-term intoxication with ethylene glycol leads to a constant generation of free radicals (increase of MDA concentration) and gradual exhaustion of the antioxidative system.