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The aim of our study was to compare levels of antioxidative agent -total SH groups and the final product of lipid peroxidation- malondialdehyde (MDA) in serum, and glutathione (GSH) and MDA in nucleocortical parts of lens after extracapsular extraction of cataract. Patient were (38 with cataract and 38 controls) matched by sex and years of life. Diagnosis of cataract was established by complete ocular examination. All results are expressed as mean ± S.D. A Student's t-test was used to estimate differences between the groups. The level of significance was p<0.05. Total sulfhydryl groups were determined in serum by the method of Ellman as well as GSH content in nucleocortical parts of lenses using the method of Sedlak and Lindsay. Lipid peroxidation, evidenced by formation of thiobarbituric acid reactive substances (TBARS), was determined in nucleocortical parts of the lens and in serum. Our results show a statistical significance in concentration of total SH groups (225.37±82.19µmol/L, controls 311.03±60.37µmol/L p<0.05) and MDA (20.24±8.12, and controls 8.73±2.53µmol/L, p<0,001) in serum among patients with age related cataract and controls. There was no statistical significance in concentration of total SH groups and MDA in serum among patients with different type of age related cataract and in nucleocortical parts of lens. The present study concludes that there is a statistical significance in concentration of total SH groups and MDA in serum among patients with age related cataract and controls, but there were no statistical significance in concentration of GSH and MDA in serum and nucleocortical parts of lens in patient with different type of cataract.

Objective: Reactive oxygen species play a crucial role in the pathogenesis of diabetic nephropathy (DN). The present study was performed to assess oxidative stress parameters-thiobarbituric acid reactive substances (TBARS), reactive carbonyl derivates (RCDs), and total sulfhydryl groups (TSHGs)-in serum and urine of patients with DN., Methods: All parameters were determined in patients with type 2 and type 1 diabetes mellitus and microalbuminuria (DMT2-MIA, DMT1-MIA, respectively) and patients with type 2 diabetes mellitus and macroalbuminuria (DMT2-MAA) compared to healthy controls., Results: Serum and urine TBARS levels were higher in all patients with DN and microalbiminuria compared to the control group. RCD levels significantly increased in serum of patients with DMT2 relative to the controls as well as in urine of patients with DMT2-MAA and DMT1-MIA. In all groups of patients, TSHGs decreased in serum but not in urine of patients with DMT2-MAA., Conclusion: Urine TBARS, RCDs, and TSHGs could be proposed as possible markers for oxidative damage of kidney in DN.

Objectives: Oxidative stress has been implicated in numerous pathological conditions including chronic tonsillitis. The aim of this study was to assess levels of lipid peroxidation, evidenced by formation of thiobarbituric acid reactive substance (TBARS), level of total sulfhydryl groups (TSH), and carbonyl content in patients with tonsillar hypertrophy (TH) and recurrent tonsillitis (RT), before and after tonsillectomy., Methods: In this study the serum and tonsillar tissue levels of TBARS, TSH and carbonyl content were investigated in 35 patients with TH and RT, before and 1 month after the operation, compared to 30 age-matched controls., Results: In both TH and RT groups, a significantly higher serum TBARS levels were observed before and 4 weeks after tonsillectomy in comparison with healthy subjects. The serum level in TH patients after operation was even higher compared to the levels before. There was statistically significant difference in serum TSH levels between patients with RT before operation compared to the control group. After tonsillectomy the serum levels of TSH were higher compared to control groups and TH and RT patients before operation. Carbonyl content was attenuated only in TH patients after tonsillectomy. In tonsillar tissue, significantly lower level of glutathione content (GSH) has been observed in RT related to TH patients., Conclusions: Oxidative stress, in patients with tonsillar hypertrophy and recurrent tonsillitis, is still present 1 month after the removal of tonsillar tissue. Antioxidant therapy, during the recovery period after tonsillectomy, could be optional treatment.

The oxidative damage of proteins and lipid peroxidation of membrane lipoproteins has already been described as a possible pathogenic mechanism for liver injury. The aim of the present study was to examine the mechanism that could be responsible for the oxidative modification of rat liver 5'-nucleotidase during exposure to different free radical generating systems: FeCl2/ascorbate, xanthine/xanthine oxidase and H2O2. The level of lipid peroxidation products malondialdehyde (MDA), as well as the level of protein carbonyl groups formation was measured in cells and extracellular medium. The activity of 5'-nucleotidase was linearly decreased in both hepatocytes and extracellular medium after exposure to the FeCl2/ascorbate system indicating that the possible mechanism for oxidative modification could be a metal-binding site of the enzyme. In xanthine/xanthine oxidase system the enzyme activity of hepatocytes had decreased in hepatocytes but increased in the extracellular medium indicating that proteolysis of membrane proteins could he responsible for enzyme release in the extracellular medium. When hepatocytes were exposed to a H2O2 free-radical generating system, the activity of 5'-nucleotidase tended to be decreased in cells and decreased in extracellular medium too, indicating that H2O2 could be less reactive in producing an oxidative modification of the enzyme. In order to support the hypothesis that the cation-binding site can be responsible for oxidative modification of the enzyme, the isolated hepatocytes were preincubated with a Ca(2+)-channel blocker (Verapamil) and then exposed to different radical-generating systems. Verapamil had only a slight effect in potentiating the inhibition in the FeCl2/ascorbate system. This probably means that the cellular cation flux and cation binding may be included as a vulnerable site with the greatest importance in the oxidative modification of 5'-nucleotidase.

Introduction/Objective. Intensive oxidative stress is proven in patients with diabetes mellitus and important in the development of a microvascular complication of type 2 diabetes mellitus. The aim of the study was to investigate the relationship between morphometric parameters of retinal blood vessels in patients with diabetic retinopathy (DR) and the levels of parameters of oxidative stress: advanced oxidation protein product (AOPP), thiobarbituric acid reactive substances (TBARS), and total sulfhydryl (SH) groups in blood samples. Methods. The patients (the group with DR and controls) were sex- and age-matched. Glycaemia, hemoglobin A1C HbA1C, total cholesterol and its fractions, and triglycerides were measured in blood samples. AOPP and total SH groups were determined in the plasma by specific methods. Modification of the thiobarbituric acid method was used for the determination of TBARS. The number and diameter of retinal blood vessels, as morphometric parameters on digital retinal photography, was determined by using the ImageJ software. Student’s t-test was used as the statistical method for the evaluation of differences between the morphometric and blood test parameters. The significance of differences in morphometric parameters of retinal blood was establish by one-way ANOVA. Results. Significantly higher levels of parameters of oxidative stress (AOPP and TBARS) were in the group of patients with DR than in the controls. This difference was also present among the patients with mild and severe forms of DR (AOPP F 77.03, p < 0.001) (TBARS F 63.28, p < 0.001). The diameter of retinal blood vessels correlated with levels of AOPP, but only in patients with mild DR. Conclusion. Parameters of oxidative stress, AOPP and TBARS, may be important for the follow-up of DR. In early stages in diabetic retinopathy, AOPP can be a valuable biomarker.

Introduction/Objective. An unfavorable prognosis of membranous nephropathy (MN) is determined by the presence of persistent proteinuria and extensive tubulointerstitial lesions at initial biopsy. Our study investigated the value of markers of renal cell dysfunction (glomerular filtration rate, urinary excretion of protein, ectoenzyme proximal tubular epithelial cells, and oxidative stress) in patients with MN, and points to the use of these markers in a possible therapeutic modification. Methods. The study included 28 patients with MN and 30 healthy individuals as control. In addition to the basic laboratory studies, enzyme [aminopeptidase N (APN), plasma cell glycoprotein-1 (PC-1), N-acetyl- β-D-glucosaminidase (NAGA), and dipeptidyl peptidase-4] activity was determined in serum and urine, as well as parameters of oxidative damage [thiobarbituric acid concentration of substance-responders (TBARS), malondialdehyde, and the concentration of the total sulfhydryl (SH) group]. Results. In patients with MN, serum activity of PC-1 and APN and urinary excretion of NAGA were significantly higher than in the control group. Also, significant correlation between daily proteinuria and serum PC-1 activity and urinary excretion of NAGA was found in patients with MN. Serum and urine levels of TBARS as well as total SH group levels were significantly lower in patients with MN than in healthy controls. Conclusion. Kidney damage in MN is accompanied by the release of several tubular enzymes, with potential diagnostic and prognostic significance. The study suggests a possible role of oxidative stress in pathogenesis of MN and the use of antioxidants in preventing impairment as part of future therapy. [Project of the Ministry of Science and Environmental Protection of Serbia, Grant No. 175092]

Background: The primary goal of this study was to evaluate the influence of cytochrome P450 (CYP) 3A5 (6986A>G) and ABCB1 (3435C>T) polymorphisms on tacrolimus (TAC) dosage regimen and exposure. Second, we evaluated the influence of TAC dosage regimen and the tested polymorphisms on renal oxidative injury, as well as the urinary activities of tubular ectoenzymes in a long-term period after transplantation. Also, we aimed to determine the association between renal oxidative stress and tubular damage markers in the renal transplant patients. Methods: The study included 72 patients who were on TAC based immunosuppression. Allele-specific PCR was used for polymorphism determination. We measured the urinary thiobarbituric acid reactive substances (TBARS) and reactive carbonyl derivates (RCD) in order to evaluate oxidative injury, as well as the urinary activities of ectoenzymes (N-acetyl-b-Dglucosaminidase, aminopeptidase N and dipeptidyl peptidase IV) to evaluate tubular damage. Results: The carriers of CYP 3A5*1 allele required statistically higher daily doses of TAC than CYP *3/*3 carriers, as well as the carriers of C allele of ABCB1 gene compared to those with T T genotype. Also, there were no differences in TBARS, RCD and the activities of ectoenzymes between the patients' genotypes. Our results showed significant correlations between urinary TBARS and RCD and the ectoenzymes' activities. Conclusions: Our findings suggest that CYP 3A5 and ABCB1 3435 polymorphism may affect TAC daily doses, but not the drug's tubular toxicity. Furthermore, tubular damage may be associated with increased renal oxidative stress.

Background: The aim of the study was to evaluate parameters of oxidative and nitrosative stress as well as antioxidative parameters in a group of renal transplant recipients with stable graft function and no clinical signs of cardiovascular disease. We also aimed to determine the correlations among these parameters and to evaluate potential differences in all the biomarkers with regard to the immunosuppression protocol. Methods: We enrolled 57 renal transplant recipients and 31 controls who were age and sex matched with the renal transplant recipients. All of the patients included in this study had post-renal transplant surgery at least 12 months earlier and were on standard immunosuppressive therapy. In this study, we determined thiobarbituric acid-reactive substances in plasma and red blood cells and advanced oxidation protein products, nitrosative stress parameters (asymmetric and symmetric dimethylarginine - ADMA and SDMA), and antioxidative parameters (total SH groups and catalase activity). Results: The results of our study demonstrated that the levels of oxidative and nitrosative stress were significantly increased compared to the healthy population (p < 0.01 except for plasma catalase activity p < 0.05). Correlation analysis showed significant positive correlations between: ADM A and SDMA (p < 0.01); ADM A and nitrates (p< 0.05); SDMA and nitrates (p < 0.05); between OS parameters in the experimental group; AOPP and SH groups (p < 0.05) and TBARS in plasma and SH groups (p < 0.01), SDMA and AOPP (p< 0.05); SDMA and TBARS in plasma (p < 0.05); SDMA and SH groups (p < 0.01); nitrates and SH groups (p < 0.05). Conclusion: There was no significant difference in oxidative and nitrosative stress parameters with respect to the immunosuppressive protocol.

Background/Aim. Reperfusion of previously ischemic tissue leads to injuries mediated by reactive oxygen species. The aim of the study was to investigate the effects of different anesthesia techniques on oxidative stress caused by tourniquetinduced ischemia-reperfusion (IR) injury during extremity operations at children's age. Methods. The study included 45 patients American Society of Anesthesiologists (ASA) classification I or II, 8 to 17 years of age, undergoing orthopedic procedures that required bloodless limb surgery. The children were randomized into three groups of 15 patients each: general inhalational anesthesia with sevoflurane (group S), total intravenous anesthesia with propofol (group T) and regional anesthesia (group R). Venous blood samples were obtained at four time points: before peripheral nerve block and induction of general anesthesia (baseline), 1 min before tourniquet release (BTR), 5 and 20 min after tourniquet release (ATR). Postischemic reperfusion injury was estimated by measurement of concentration of malondialdehyde (MDA) in plasma and erythrocytes as well as catalase (CAT) activity. Results. Plasma MDA concentration in the group S was significantly higher at 20 min ATR in comparison with the groups T and R (6.78 ± 0.33 μmolL-1-1 vs 4.07 ± 1.53 and 3.22 ± 0.9. μmolL-1-1, respectively). There was a significant difference in MDA concentration in erytrocythes between the groups S and T after 5 min of reperfusion (5.88 ± 0.88 vs 4.27 ± 1.04 nmol/mlEr, p < 0.05). Although not statistically significant, CAT activity was slightly increased as compared to baseline in both groups S and R. In the group T, CAT activity decreased at all time points when compared with baseline, but the observed decrease was only statistically significant at BTR (34.70 ± 9.27 vs 39.69 ± 12.91 UL-1, p < 0.05). Conclusion. Continuous propofol infusion and regional anesthesia techniques attenuate lipid peroxidation and IR injury connected with tourniquet application in pediatric extremity surgery.

Oxidative stress is considered to be a unifying link between diabetes mellitus (DM) and its complications, including nephropathy (DN). The aim of this study was to determine the parameters of oxidative injury of lipids and proteins as well as the activity of ectoenzymes in the urine of DN patients. The study included 40 individuals: 10 patients with type 2 diabetes mellitus and microalbuminuria (DMT2-MIA), 10 type 2 diabetic patients with macroalbuminuria (DMT2- MAA), 10 patients with type 1 diabetes and microalbuminuria (DMT1-MIA) and 10 age- and sex-matched healthy subjects (control). In the urine we determined TBA reactive substances (TBARS), reactive carbonyl groups (RCG), and the activity of ectoenzymes N-acetyl-b-d-glucosaminidase (NAG), plasma cell differentiation antigen (PC-1), aminopeptidase N (APN) and dipeptidyl peptidase IV (DPP IV). A higher concentration of TBARS in the urine was found in DMT2-MIA and DMT1-MIA, compared to the control group (p