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Abstract Background and Aim Maintenance haemodialysis patients have increased morbidity and mortality which is mainly driven by an elevated inflammation level due to the uraemic milieu. A major part of this increased inflammation level is the degree of oxidative stress which can be assessed by albumin redox state (ARS). Aim of this study was to evaluate how the ARS is affected by a haemodialysis treatment and different dialyzer properties. Methods ARS was determined before and after haemodialysis treatment by fractionating it into reduced human mercaptalbumin (HMA), reversibly oxidized human non-mercaptalbumin 1 (HNA-1), and irreversibly oxidized human non-mercaptalbumin 2 (HNA-2) by high-performance liquid chromatography. In healthy individuals, albumin circulates in the following proportions: HMA 70–80%, HNA-1 20–30% and HNA-2 2–5%. High flux (FX 100 [Fresenius Medical Care], BG 1.8 [Toray], Xevonta Hi 18 [B. Braun], CTA-2000 [Kawasumi]) and low flux FX10 [Fresenius Medical Care] dialyzers were used. Results 58 patients (59% male, median age 68 years, median time on haemodialysis 32 month) were included in the study. Before haemodialysis treatment, HMA (median 55.9%, IQR 50.1–61.2%) was substantially lower than in healthy individuals. Accordingly, oxidized albumin fractions were above the level of healthy individuals (median HNA-1 38.5%, IQR 33.3–43.2%; median HNA-2 5.8%, IQR 5.1–6.7%). Before haemodialysis treatment HMA was significantly higher in patients usually treated with high flux membranes (p

Background and Aim: Maintenance haemodialysis patients have increased morbidity and mortality which is mainly driven by an elevated inflammation level due to the uraemic milieu. A major part of this increased inflammation level is the degree of oxidative stress which can be assessed by albumin redox state (ARS). Aim of this study was to evaluate how the ARS is affected by a haemodialysis treatment and different dialyzer properties. Methods: ARS was determined before and after haemodialysis treatment by fractionating it into reduced human mercaptalbumin (HMA), reversibly oxidized human non-mercaptalbumin 1 (HNA-1), and irreversibly oxidized human non-mercaptalbumin 2 (HNA-2) by high-performance liquid chromatography. In healthy individuals, albumin circulates in the following proportions: HMA 70–80%, HNA-1 20–30% and HNA-2 2–5%. High flux (FX 100 [Fresenius Medical Care], BG 1.8 [Toray], Xevonta Hi 18 [B. Braun], CTA-2000 [Kawasumi]) and low flux FX10 [Fresenius Medical Care] dialyzers were used. Results: 58 patients (59% male, median age 68 years, median time on haemodialysis 32 month) were included in the study. Before haemodialysis treatment, HMA (median 55.9%, IQR 50.1–61.2%) was substantially lower than in healthy individuals. Accordingly, oxidized albumin fractions were above the level of healthy individuals (median HNA-1 38.5%, IQR 33.3–43.2%; median HNA-2 5.8%, IQR 5.1–6.7%). Before haemodialysis treatment HMA was significantly higher in patients usually treated with high flux membranes (p < 0.01). After haemodialysis treatment there was a significant increase of HMA and a decrease of HNA-1 and HNA-2 (p < 0.01). These effects were more pronounced in patients treated with high flux dialyzers (p < 0.01). There were no differences of ARS alteration with regard to the dialyzer´s sterilization mode or the presence of diabetes. Conclusion: The study confirms that the ARS is positively altered by haemodialysis and shows for the first time that this effect depends on dialyzer properties. [ABSTRACT FROM AUTHOR]

Like in many other pathologies, oxidative stress is involved in the development of neurodegenerative disorders. Human serum albumin (HSA) is the main protein in different body fluids including cerebrospinal fluid (CSF). By its redox state in terms of cysteine-34, albumin serves as marker for oxidative burden. We aimed to evaluate the redox state of HSA in patients with multiple sclerosis in serum and CSF in comparison to controls to identify possible correlations with disease activity and severity. Samples were stored at −70 °C until analysis by HPLC for the determination of albumin redox state in terms of the fractions of human mercaptalbumin (HMA), human nonmercaptalbumin1 (HNA1), and human nonmercaptalbumin2 (HNA2). Albumin in CSF showed significantly higher fractions of the reduced form HMA and decreased HNA1 and HNA2. There was no difference between albumin redox states in serum of patients and controls. In CSF of patients HNA2 showed a trend to higher fractions compared to controls. Albumin redox state in serum was associated with physical disability in remission while albumin redox state in CSF was related to disease activity. Thus, albumin redox state in serum and CSF of patients in relation to disease condition merits further investigation. [ABSTRACT FROM AUTHOR]

Elevated oxidative stress ( OS) is associated with severe cardiovascular disease and premature death among patients treated with hemodialysis ( HD). Oxidative stress is enhanced by contact between blood and dialysis membranes during HD sessions. This study aimed to clarify whether hydrogen ( H2), which is a known antioxidant, is capable of suppressing increased OS induced during HD sessions. Eight patients on regular HD treatment were studied. Two HD sessions were performed in a cross-over design trial using standard and hydrogen-enriched solutions (mean of 50 p.p.b. H2; H2- HD). Blood samples were obtained from the inlet and outlet of the dialyzer during HD to determine changes in plasma levels of glutathione, hydrogen peroxide, and albumin redox state as a marker of OS. Comparison of inlet and outlet blood revealed significant decreases in total glutathione and reduced glutathione, as well as significant increases in hydrogen peroxide in both HD treatments. However, the mean proportion of reversibly oxidized albumin in outlet serum was significantly lower than that in inlet serum following the H2- HD session, whereas no significant changes were found in the standard solution session, suggesting that 'intra-dialyzer' OS is reduced by H2- HD. In conclusion, the application of H2-enriched solutions could ameliorate OS during HD. [ABSTRACT FROM AUTHOR]

Oxidative stress is enhanced in advanced chronic kidney disease (CKD) patients and recognized as a main contributor to cardiovascular disease. Carbonyl stress is also known to be enhanced in advanced CKD; however the precise relationship between oxidative stress and carbonyl stress is not clear. The aim of this study was to investigate potential relationships between oxidative stress, carbonyl stress, and renal function among predialysis patients with CKD. A total of 32 predialysis CKD patients (22 male, 10 female) were divided into four groups according to their values for creatinine clearance (Ccr) (group A, ≥60 ml/min; group B, 45–59 ml/min; group C, 30–44 ml/min; group D, ≤29 ml/min). As main markers of oxidative and carbonyl stresses, the redox state of Cys-34 (free thiol group) of human serum albumin [HSA(Cys-34)-redox] and the carbonyl content of serum proteins were employed, respectively. The values for the fraction of both reversibly oxidized HSA [ f(HNA-1)] and irreversibly oxidized HSA [ f(HNA-2)] significantly increased with a decrease in renal function (group A, 21.0 ± 3.4 and 1.8 ± 0.3%; group D, 31.1 ± 4.1 and 2.7 ± 0.9%, respectively). The value for carbonyl content also significantly increased with a decrease in renal function (group A, 0.7 ± 0.1 nmol/mg protein; group D, 1.1 ± 0.2 nmol/mg protein). There was a significant positive correlation between carbonyl content and the f(HNA-2) value, while such a correlation was not observed between carbonyl content and the f(HNA-1) value, suggesting that there is a close relationship between serum protein carbonylation and irreversible albumin thiol oxidation. There is a close relationship between oxidative stress and carbonyl stress and these are enhanced in correlation with the level of renal dysfunction among predialysis CKD patients. [ABSTRACT FROM AUTHOR]

The article presents a study on the effects of aerobic exercises intensities during a long-term antioxidant supplementation on plasma protein modification. The study which was approved by the Human Ethics Committee at the Medical University of Graz, Austria involves 41 trained men from homogenous population, who submitted to perform cycle ergometer exercises and were randomly assigned to undergo either juice powder concentrate (JPC) or placebo capsules for 28 weeks. Blood samples were collected for analysis of the concentration of carbonyl groups on plasma proteins (CP) and the redox state of human serum albumin (HSA). The results of the study have determined that HSA can act as a redox system in plasma under arduous exercise.

Background: Oxidative stress (OS) is reportedly enhanced in patients receiving regular hemodialysis (HD). However, the in vivo redox state of HD patients, particularly after HD sessions, remains unclear. This study aimed to clarify the influence of HD on OS using the albumin redox state as a marker. Method: Blood samples of 8 regular HD patients were obtained during the course of study. The redox state of albumin was determined using high-performance liquid chromatography. Results: The mean fraction of reversibly oxidized albumin [f(HNA-1)] declined significantly over the course of the session and reached a minimum 4 h after the session had ended (pre-HD, 36.16 ± 7.50%; 4 h after HD, 25.71 ± 6.41%), then gradually rose to predialytic levels. The proportion of irreversibly oxidized albumin did not change significantly over time. Positive correlations were demonstrated between f(HNA-1) and uremic small solutes in each case. Conclusion: Accumulation of dialyzable uremic solutes may contribute to OS in HD patients. [ABSTRACT FROM AUTHOR]