Hasan Bilinc

Dimethoate-induced oxidative stress and DNA damage in Oncorhynchus mykiss.

The present study was conducted in order to investigate pro-oxidant activity of dimethoate in liver and brain tissues following sublethal pesticide exposure for 5, 15 and 30 d by using SOD, GPx, CAT enzyme activities and lipid peroxidation as biomarkers as well as DNA damaging potential via detecting% Tail DNA, Tail moment and Olive tail moment as endpoints in erythrocytes of Oncorhynchus mykiss in an in vitro experiment. Antioxidant enzyme activities were found to elicit two staged response which was an initial induction followed by a sharp inhibition in liver tissue while a sustained increase in GPx activity and slight stimulation in SOD activity were detected in brain tissue. Lipid peroxidation showed an ascending pattern throughout the exposure period in both tissues and a decreasing trend was determined in tissue protein levels which was proved to be positively correlated with duration. Similar findings were obtained from outcomes preferred to quantify DNA damage and TM was decided to reflect the extent of damage more sensitively because of determined positive correlation with concentrations applied. Considering these results, it can be concluded that oxidative stress condition evoked by dimethoate could not be responded effectively and genotoxic nature of pesticide was proven by determined clastogenic effect possibly via being an alkylation agent or stimulating the production of reactive species.

Paraoxonase and arylesterase activity and total oxidative/anti-oxidative status in patients with chronic adenotonsillitis

OBJECTIVES The aim of this study was to investigate serum paraoxonase, arylesterase activities along with determination of oxidative status via measurement of total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI) in children with recurrent adenotonsillitis during pre- and post-adenotonsillectomy period and to compare results with data from healthy subjects. METHODS We performed a prospective controlled trial on adenoidectomy and/or tonsillectomy patients. A total of 47 subjects, including 22 patients with recurrent adenotonsillitis and 25 healthy controls were enrolled in this study. Peripheral venous blood samples were taken from patients before adenotonsillectomy and a second sample was obtained in first month postoperatively. In the control group, blood samples from healthy volunteers were collected for one time only. Serum paraoxonase, arylesterase activities, TOS, TAS and OSI levels were measured. RESULTS Paraoxonase, arylesterase activity, TAS and TOS levels were significantly higher in preoperative group compared to control group (P<0.001, P=0.003, 0.003 and 0.005, respectively). However, OSI level was similar in preoperative group compared to control group (P=0.25). In the post-operative group, paraoxonase, arylesterase activities, TAS and OSI levels were lower as compared to preoperative group but differences were statistically insignificant (P=0.483, 0.265, 0.149 and 0.090, respectively). TOS level in post-operative group was significantly lower than the preoperative group (P<0.001). In the post-operative group, paraoxonase and arylesterase activities were significantly higher as compared to control group (P=0.004 and 0.02, respectively). TOS and OSI levels were significantly lower in post-operative group compared to control group (P=0.001 and 0.02, respectively). However, TAS was similar between post-operative and control groups (P=0.464). CONCLUSIONS Based on data obtained from this study, we may state that paraoxonase, arylesterase activities with TAS, TOS and OSI levels of patients with chronic adenotonsillitis shows alterations due to oxidant/antioxidant imbalance induced by frequent infections.

Oxidative stress in chronic otitis media

Chronic otitis media usually presents with a benign tumor-like lesion of the temporal bone known as a cholesteatoma. The role of oxidative stress in the pathogenesis of chronic otitis media and cholesteatoma has not yet been fully explored. Therefore, the aim of this study was to investigate the oxidative stress markers and antioxidant enzymes in patients with cholesteatomatous and noncholesteatomatous chronic otitis media and in healthy subjects. A prospective controlled trial was performed on cholesteatomatous and noncholesteatomatous chronic otitis media patients in a tertiary referral center in a university hospital. A total of 75 subjects, including 25 cholesteatomatous and 25 noncholesteatomatous chronic otitis media patients and 25 healthy subjects participated in this study. Serum total oxidant status (TOS) and oxidative stress index (OSI) levels were significantly increased in the patient groups with or without cholesteatoma compared with the control group. Serum total antioxidant status (TAS) levels and Paraoxonase and arylesterase activity were significantly lower in the patient groups with or without cholesteatoma compared with the control group. Serum TOS and OSI levels were lower in the noncholesteatomatous group, whereas serum TAS levels were higher compared with the cholesteatomatous group. Serum arylesterase activity was significantly lower in the noncholesteatomatous group compared with the control group. The results of this study reveal that in cholesteatoma cases, the oxidative stress and antioxidant enzyme imbalance were more significant than in cases of chronic otitis media without cholesteatoma.

Increased oxidative stress in children with attention deficit hyperactivity disorder

Objectives: The purpose of this study was to investigate oxidative stress in children with attention deficit hyperactivity disorder (ADHD). Methods: Total oxidant status (TOS), total antioxidant status (TAS), paraxonase-1 (PON-1) and arylesterase (ARE) activity were measured in 76 children (44 boys, 32 girls) diagnosed with ADHD according to the DSM-IV and 78 healthy children (46 boys, 32 girls). Results: Age and sex were similar between the groups (P > 0.05). TOS and the oxidative stress index (OSI) were higher in the patient group than the control group (P < 0.001). PON-1 (P = 0.002), ARE (P = 0.010) activity and TAS (P < 0.001) were lower in the patient group than the control group. Discussion: We found decreased PON-1, ARE activity and TAS, and increased TOS and OSI in children with ADHD. Our study showed that there is significantly increased oxidative stress in children with ADHD.

Evaluation of Oxidative Stress Parameters and Urinary Deoxypyridinoline Levels in Geriatric Patients with Osteoporosis

[Purpose] To evaluate the oxidative stress parameters and urinary deoxypyridinoline levels in geriatric patients with osteoporosis. [Subjects and Methods] Eighty geriatric patients aged over 65 years were recruited. Patients were divided into two groups: Group 1 (n=40) consisted of patients with osteoporosis, and Group 2 (n=40) consisted of patients without osteoporosis. Bone mineral density measurements were performed for all patients using DEXA. Oxidative stress parameters were analyzed in blood samples, and deoxypyridinoline levels were analyzed in 24-hour urinary samples. [Results] Compared to Group 2, the total antioxidant status and oxidative stress index levels of Group 1 were not significantly different; however, total oxidant status and 24-hour urinary deoxypyridinoline levels were significantly higher. Pearson correlation coefficients indicated that OSI and urinary deoxypyridinoline levels were not correlated with any biochemical parameters. ROC-curve analysis revealed that urinary deoxypyridinoline levels over 30.80 mg/ml predicted osteoporosis with 67% sensitivity and 68% specificity (area under the curve = 0.734; %95 CI: 0.624–0.844). [Conclusion] Our results indicate that oxidative stress would play a role in the pathogenesis of osteoporosis, and that urinary deoxypyridinoline levels may be a useful screening test for osteoporosis.

Protective activity of ischemic preconditioning on rat testicular ischemia: Effects of Y-27632 and 5-hydroxydecanoic acid

BACKGROUND/PURPOSE The aim of this study was to investigate the role of ischemic preconditioning (IPC) on ischemia/reperfusion (I/R)-induced injury of rat testis and determine the effects of 5-hydroxydecanoic acid (5-HD), a selective K(ATP) channel antagonist, and Y-27632, a selective Rho kinase inhibitor, on IPC. METHODS I/R injury was induced by 180 min ischemia and 60 min reperfusion of testis. There were 5 groups. Group 1 served as untreated controls. The rats in Group 2 were subjected to I/R only. In Group 3, 3 cycles of IPC (5 min transient ischemia plus 5 min reperfusion) were performed prior to I/R. In groups 4 and 5, the rats were treated as in Group 3 but received intraperitoneal injections of 0.3 mg/kg Y-27632 or 10 mg/kg 5-HD prior to IPC, respectively. RESULTS I/R led to severe histopathological lesions in the rat testis and significantly lowered the scoring. I/R resulted in significant elevation in tissue lipid peroxide levels, myeloperoxidase (MPO) activity, and total antioxidative capacity (TAC), total oxidative status, and oxidative stress index levels. Protective effects of IPC on I/R-induced testicular injury of rats were observed with the significant recovery in these biochemical parameters. Y-27632 treatment led to a significant decrease in MPO activity, but there were no significant changes in the remaining parameters. Effects of IPC were blocked by 5-HD except in the TAC levels. CONCLUSION Our results showed that IPC protected rat testis against I/R-induced injury via activation of KATP channels. Additionally, Rho kinase inhibition preserved the effects of IPC in testis.

The activity of paraoxonase and arylesterase in patients with osteomyelitis

Background. The aim of this study was to evaluate oxidative stress and to determine the activity of paraoxonase and arylesterase in patients with osteomyelitis compared to healthy controls. Method. In total, 30 patients diagnosed with osteomyelitis and 30 healthy volunteers were enrolled in the study. Paraoxonase and arylesterase activities were measured spectrophotometrically. Serum lipid hydroperoxide (LOOH) concentrations were measured by ferrous oxidation with xylenol orange (FOX) assay as markers of oxidative stress. Results. Serum paraoxonase and arylesterase activities were significantly lower in patients with osteomyelitis compared to control individuals (all p < 0.05). Serum LOOH concentrations were significantly higher in patients with osteomyelitis than those in controls (p < 0.05). Arylesterase activity was inversely correlated with triglyceride (r =− 0.49; p = 0.005) and cholesterol concentrations (r =− 0.41; p = 0.025). Conclusion. In light of the findings obtained from the present study, it may be assumed that decreased activity of serum paraoxonase and increased concentrations of LOOH observed in osteomyelitis patients appear to be related to the increased oxidative stress and inflammatory conditions present in these patients, and may cause a much more severe status of the disease.

Paraoxonase Activity and Oxidative Status in Patients with Tinnitus

Background and Objectives The aim of this study was to investigate serum paraoxanase-1 (PON) activity, total oxidant status (TOS), total antioxidant status (TAS), and the oxidative stress index (OSI) in tinnitus; and to compare the results with data from healthy subjects. Subjects and Methods A total of 114 subjects-54 patients with tinnitus and 60 healthy controls were enrolled in this study. Serum PON activity, TOS, TAS, and OSI levels were measured. Results In the tinnitus group, TAS, and PON were significantly lower than in the control group (p<0.001). However, the TOS, and OSI levels were significantly higher in the tinnitus group than in the control group (p<0.001). Conclusions According to the data obtained from the present study, patients with tinnitus were exposed to potent oxidative stress. Oxidative stress may be the key contributing factor to the pathogenesis of tinnitus.

Oxidant/Antioxidant Status in Cases of Snake Bite

BACKGROUND Snake bites are an important cause of mortality and morbidity worldwide, especially in rural areas. OBJECTIVE The aim of this study was to investigate serum paraoxonase (PON), arylesterase (ARLY), ceruloplasmin (Cp), and myeloperoxidase (MPO) activity and lipid hydroperoxide (LOOH) and total sulfhydryl group (-SH) levels in patients with snake venom poisoning. METHODS The study included 49 patients with snake bite envenomation (Group 1) and 39 healthy volunteers as the control group (Group 2). Plasma PON, ARLY, Cp, and MPO activity and LOOH and -SH levels were measured. Laboratory measurements of 20 patients with snake bite envenomation (Group 3) were performed again after treatment. RESULTS PON and ARLY activity and -SH levels were significantly decreased in Group 1 compared with those in Group 2. Cp and MPO activity and LOOH levels were significantly elevated in Group 1 compared with those in Group 2. PON and ARLY activity were significantly elevated in Group 3 compared with those in Group 1. Cp and MPO activity and LOOH levels were significantly decreased in Group 3 compared with those in Group 1. CONCLUSIONS Patients with snake bite envenomation had increased oxidants (MPO and LOOH) and decreased antioxidants (PON, ARLY, and -SH). Results obtained in this study demonstrate that snake bites are associated with a shift to oxidative status. Therapy with antioxidants can lead to an increase in the antioxidant defense system, and thus improvements in clinical symptoms.

Beta-globin gene mutations in children with beta-thalassemia major from Şanlıurfa province, Turkey.

OBJECTIVE The prevalence of β-thalassemia in Şanlıurfa province, Turkey is reported to be 2.6%-3.7%, whereas nation-wide the frequency of β-thalassemia is 2%. This study aimed to identify the most frequent β-thalassemia mutations in Şanlıurfa province. METHODS In total, 22 mutations were investigated in 115 pediatric patients with β-thalassemia using a commercially available reverse dot blot platform. RESULTS The study included 60 male and 55 female patients with a mean age of 7.3±4.6 years (range: 1-17 years). In total, 76% of the patients had consanguineous parents. In all, 16 different mutations were observed in the 115 patients. IVS-1-110 (G-A) (29.1%), IVS-1-1 (G-A) (13.9%), codon 39 (C>T) (10.4%), and codon 8 (-AA) (9.1%) accounted for 62.5% of all the β-thalassemia mutations, and 6% of the patients had 2 different thalassemia mutations. According to the present results, IVS-1-110 (G>A) was the most frequent mutation observed in the patients from Şanlıurfa province, as in other geographical regions of Turkey. In addition, the following 34 compound heterozygote mutant alleles were observed; IVS-1-1 (G>A)/IVS 2.848 (n=4), codon 39 (C>T)/codon 8 (-AA) (n=2), codon 6 (-A)/IVS 1.5 (G>C) (n=2), IVS-1-110 (G>A)/IVS-1-1 (G>A) (n=2), IVS-1-110 (G>A)/codon 8 (-AA) (n=1), IVS-1-110 (G>A)/codon 39 (C>T) (n=1), IVS-1-110 (G>A)/IVS-1-6 (T>C) (n=1), IVS-1-110 (G>A)/IVS-1-5 (G>C) (n=1), IVS-1-110 (G>A]/codon 8/9 (+G) (n=1), IVS-1-1 (G>A)/codon 39 (C>T) (n=1), and codon 8 (-AA)/IVS-1-5 (G>C) (n=1). The following β-globin gene promoter mutations were not observed; -101 (C>T), -87(C>T), -30 (T>A), codon 15 (TTG>TGA), codon 27 (G>T) Knossos, and IVS-1-116 (G>C). In all, 5 of the 115 patients (4.3%) had an unidentified mutation. CONCLUSION The present results illustrate the heterogeneity of β-thalassemia mutations in Şanlıurfa Province. The present findings may be of value for genetic counseling, and premarital and prenatal diagnosis in Şanlıurfa province.