Necati Muslu

Role of oxidative stress enzymes in open-angle glaucoma

PurposeTo investigate the role of oxidative stress and lipid peroxidation in the pathogenesis of primary open-angle glaucoma (POAG).Materials and methodsThe activities of myeloperoxidase (MPO), catalase (CAT), and the levels of plasma malondialdehyde (MDA) were measured in 40 (15 men and 25 women) patients with POAG and 60 (30 men and 30 women) healthy controls.ResultsThere was no significant difference in the activities of CAT and MPO between the POAG patients and the controls. However, the plasma MDA level was significantly higher in patients than the controls.ConclusionThe results of this preliminary study suggest that the possible alterations of plasma MDA levels may be associated with the pathogenesis of POAG, but further research is needed to understand the role of oxidative damage in this important disorder of aging.

Changes in antioxidant enzyme activity and malondialdehyde level in patients with age-related macular degeneration.

Age-related macular degeneration is the leading cause of legal blindness in the developed world, and yet its pathogenesis remains poorly understood. Oxidative stress may play a major role in the etiology and pathogenesis of age-related disorders such as age-related macular degeneration. Catalase is an antioxidant enzyme which plays an important role in the detoxification of free oxygen radicals. Malondialdehyde is a marker that shows free radical damage. We have measured the erythrocyte activity of catalase and the serum level of malondialdehyde in 30 patients with age-related macular degeneration and 60 healthy subjects. Patients with age-related macular degeneration showed significantly lower catalase activity compared to healthy subjects (p = 0.002). Plasma malondialdehyde level of the patient group was significantly higher than that of the controls (p = 0.038).

Plasma visfatin level in lean women with PCOS: relation to proinflammatory markers and insulin resistance

Objectives. The present study was undertaken to investigate the association between plasma visfatin concentrations and inflammatory markers such as interleukin-6 (IL-6) and high-sensitive C-reactive protein (hsCRP) in company with several metabolic parameters in lean women with polycystic ovary syndrome (PCOS). Methods. The study group consisted of 21 lean women with PCOS (BMI 20.74 ± 1.74 kg/m2) and 15 healthy, normally menstruating women (BMI 20.85 ± 2.08 kg/m2 control group). PCOS was defined according to the Rotterdam criteria. Visfatin, IL-6, hsCRP, hyperandrogenism markers and metabolic markers were examined in all PCOS and control women. Results. Plasma visfatin level in the PCOS group was higher than that in the control group. Plasma hsCRP and IL-6 levels in PCOS group were similar with the control group. Plasma visfatin levels were positively associated with total cholesterol, high density lipoprotein, hirsutism score, total testosterone and FAI. Plasma visfatin level was negatively associated with SHBG. However, there were no correlation between plasma visfatin level and IL-6 and hsCRP. In multivariate regression analyses, only FAI and high density lipoprotein-cholesterol (HDL-C) showed a significant association with serum visfatin. Conclusion.  Our data indicates that plasma visfatin levels are associated with HDL-C and markers of hyperandrogenism, but it is not associated with proinflammatory markers and insulin resistance in lean women with PCOS.

Serum leptin levels in patients with allergic rhinitis

OBJECTIVE: To investigate the serum leptin levels in patients with allergic rhinitis during the symptomatic period. STUDY DESIGN AND SETTING: A randomized, prospective study was performed on 26 adult patients with allergic rhinitis and 20 control subjects with similar age, sex and body mass index in a tertiary otolaryngology center. RESULTS: Leptin levels were 28.8 ± 14.1 ng/mL in the patients with allergic rhinitis, and 20.8 ± 13.5 ng/mL in the control group respectively. The difference between the groups was statistically significant (p = 0.04). CONCLUSION: Serum leptin levels were found to be significantly higher in patients with allergic rhinitis in symptomatic period. SIGNIFICANCE: Apart from its primary role in the regulation of body weight and energy expenditure, leptin may have a role in the inflammatory process of the allergic rhinitis.

Serum retinol binding protein 4 level is related with renal functions in Type 2 diabetes

Aim: We aimed to evaluate the metabolic parameters and diabetes complications which would probably affect the serum retinol-binding protein 4 (RBP4) levels in Type 2 diabetic individuals. In addition to serum RBP4 concentration, the levels of its ligands, serum retinol and transthyretin (TTR) were also considered in this evaluation. Subjects and methods: Serum RBP4, retinol, and TTR levels were measured in 53 Type 2 diabetic subjects and 30 body mass index (BMI)-matched controls. The molar ratios of RBP4 to retinol and RBP4 to TTR were compared. Results: While the RBP4 values were similar to those in the control group in Type 2 diabetic patients, the molar ratio of RBP4 to TTR was found to be higher than that of the control group. The serum RBP4 levels in patients who had retinopathy and macrovascular disease were similar to those in patients who did not. However, the RBP4 levels, molar ratios of RBP4 to retinol and RBP4 to TTR in micro-macroalbuminuric patients were found to be significantly higher than in normoalbuminuric subjects and controls. There was no correlation between the RBP4 levels and the patients’ age, BMI, duration of diabetes, LDL, triglyceride, serum creatinine, and glycated hemoglobin values. Micro-macroalbuminuria and estimated glomerular filtration rate were independent determinants for increased serum RBP4 levels. Conclusion: According to the data obtained from this study, diabetic retinopathy and cardiovascular complications do not affect the serum RBP4 level in Type 2 diabetes. Renal functions rather than the metabolic factors of diabetes determine the RBP4 level and its relation with its ligands.

Plasma catalase activity and malondialdehyde level in patients with cataract

AbstractPurpose Oxidative mechanisms play a major role in the aetiology and pathogenesis of cataract, especially in age-related cataract. Our study aims to investigate systemic oxidant and antioxidant markers in cataract patients.Methods The activity of erythrocyte catalase and the level of malondialdehyde in plasma were measured in 40 patients with cataract and 60 healthy control subjects. The malondialdehyde level, as an index of lipid peroxidation, was determined by thiobarbitüric acid reaction according to Yagi. The determination of catalase activity was measured by a method that was defined by Beutler. Catalase enzyme activity and malondialdehyde level were evaluated to find out whether there was a significant difference in these variables. Analysis of variance was used by forming a general linear model that takes age and gender as the covariate.Results CAT activity was found to be 13 920.2±847.9 U/l in cataract patients and 16 061.3±1126.6 U/l in control subjects. CAT activity in cataract patients was significantly lower than the control subjects (P=0.008). Plasma MDA level is significantly higher in patients with cataract 4.47 ± 0.35 nmol/ml compared to the control subjects 2.94±0.26 nmol/ml (P=0.0001). There was no significant difference between different cataract subgroups when erythrocyte CAT activities and plasma MDA levels were compared (P=0.322, 0.062).Conclusion This study shows that oxidant/antioxidant balances alter in the presence of cataract.

Leukotriene C4 synthase A-444C gene polymorphism in patients with allergic rhinitis.

OBJECTIVE: To determine the frequency of leukotriene C4 synthase A-444C polymorphism in allergic rhinitis patients. STUDY DESIGN AND SETTING: A prospective, randomized, case-controlled study. Blood samples were obtained from 85 patients with allergic rhinitis and 95 healthy individuals. After the extraction of DNA from the blood samples, the leukotriene C4 synthase A-444C polymorphism was studied by a real-time polymerase chain reaction method. RESULTS: The AC and CC genotype frequencies were statistically higher in the study group (P = 0.048 and P = 0.037, respectively). In addition, the AC polymorphism carried an increased risk of developing allergic rhinitis (odds ratio = 2.18, 95% confidence interval, 1.173–4.053, P = 0.014). CONCLUSION: The C allele of the leukotriene C4 synthase gene increases the risk of developing allergic rhinitis. SIGNIFICANCE: The leukotriene C4 synthase A-444C gene polymorphism is important in susceptibility to allergic rhinitis and this is the first study of this gene polymorphism in allergic rhinitis.

The protective effects of acetylsalicylic acid on free radical production in cisplatin induced nephrotoxicity: an experimental rat model.

Abstract Cisplatin-induced nephrotoxicity is closely associated with an increase in lipid peroxidation. In several previous reports it was claimed that acetylsalicylic acid (ASA) shows its therapeutic potential as a free radical scavenger. The aim of the study was to investigate effects of ASA on cisplatin induced nephrotoxicity in an experimental rat model. Control animals (n:7) were administered 1 mL saline solution intraperitoneal (i.p.). Cisplatin group (n:7) was treated with a single dose of cisplatin i.p. (6 mg/kg), ASA group (n:7) was treated with i.p. (2.5 mg/kg) per day during the study, cisplatin plus ASA group (n:7) was administered single dose cisplatin i.p. (6 mg/kg) plus ASA (2.5 mg/kg) during 5 days. At the end of the study, Catalase (CAT), Glutathione Peroxidase (GSH-Px), Superoxide Dismutase (SOD), Nitric Oxide Synthase (NOS) enzymes activities and Malondialdehyde (MDA), Antioxidant Potential (AOP) levels were measured in both erythrocytes and renal tissues. Urea and creatinine levels and renal tissue necrosis in cisplatin plus ASA group were significantly lower than cisplatin group (p = 0.000, p = 0.014, p = 0.015). SODr activities and MDAr levels of cisplatin plus ASA group were also significantly lower than cisplatin group (p = 0.000, p = 0.029). These results show that cisplatin and ASA combination decreases the levels of urea and creatinine, reduces necrosis and improves antioxidant enzyme activities, MDA and AOP in rat kidney.

The correlation of thrombolysis in myocardial infarction frame count with insulin resistance in patients with slow coronary flow

BackgroundIt has been reported that coronary endothelial dysfunction plays an important pathogenetic role in patients with slow coronary flow (SCF). Insulin resistance is defined as impairment of insulin-stimulated glucose and/or lipid metabolism, while endothelial dysfunction is defined as paradoxical or inadequate endothelial-mediated vasodilation. In this study, we aimed to evaluate insulin resistance in patients with SCF. MethodsThe study population included 25 patients with SCF and 28 healthy controls. Insulin resistance was estimated via homeostasis model assessment insulin resistance index (HOMA-IR). ResultsPatients with SCF had higher high-sensitive C-reactive protein (hs-CRP) and HOMA-IR scores (P<0.05) than controls. Mean thrombolysis in myocardial infarction frame count had significant correlation with hs-CRP, fasting plasma insulin levels and HOMA-IR score (r=0.566, P<0.05; r=0.883, P<0.05; r=0.884, P<0.05, respectively). ConclusionIn patients with SCF, thrombolysis in myocardial infarction frame counts and hs-CRP are correlated with increased insulin resistance and thus, it can be suggested that insulin resistance and inflammation may, in part, have a role in the pathogenesis of SCF.

The effects of pentoxifylline on lung inflammation in a rat model of meconium aspiration syndrome

ABSTRACT To examine the effects of pentoxifylline (PTX) on regional pulmonary and systemic inflammation after meconium aspiration, we studied 26 anesthetized and ventilated adult rats for 3 hours. Seventeen rats were instilled with human meconium (1.5 mL/kg, 65 mg/mL) intratracheally. After instillation of meconium, PTX (20 mg/kg, i.a.; n = 9) or saline (n = 8) was given to the subjects. Nine rats that were ventilated and not instilled with meconium served as sham group. Meconium instillation resulted in increased bronchoalveolar lavage (BAL) fluid tumor necrosis factor-α (TNF-α; P = 0.004 and P = 0.002, respectively), protein (P = 0.005 and P = 0.001, respectively) levels, and arterial oxygenation index (OI) in PTX and saline groups. PTX treatment prevented the increase of BAL fluid TNF-α, protein concentrations, and OI in the meconium-instilled lungs but had no statistically significant effect. These results indicate that meconium aspiration induces severe inflammation in the lung. PTX treatment affects the TNF-α production in the lungs and it may attenuate meconium-induced derangements.