Browsing by Author "Ozbey, Ulku"

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Changes in Nitric Oxide Levels and Erythrocyte Arginase Activities in Patient With Down Syndrome
(Academic Journals, 2012) Ozbey, Ulku; Seyran, Ayse; Erisir, Mine; Benzer, Fulya; Savucu, Yuksel
Down syndrome is a chromosome abnormality with specific clinical symptoms and mental retardation caused by trisomy of chromosome 21. There is evidence that oxygen free radicals play an important role in the pathophysiology of many neuropsychiatric disorders. Although, it has not been investigated yet, several recent studies proposed that nitric oxide related to oxidative stress and arginase may have a pathophysiological role in mental retardation. The purpose of this study was to determine plasma nitric oxide levels and erythrocyte arginase activities in patients with Down syndrome and in healthy children. Plasma nitric oxide levels and erythrocyte arginase activity were measured in 20 patients with Down syndrome (median age: 15.6 +/- 7.5) and 20 age-matched healthy subjects (median age: 16.2 +/- 7.4). Significant differences were found between erythrocyte arginase activity of the patients with Down syndrome (35.2 +/- 2.7 U/g hemoglobin (Hb)) and those of healthy children (43.5 +/- 2.9 U/g Hb), (P < 0.05). But we have not found any statistical difference between persons with Down syndrome and control group for nitric oxide (P > 0.05). It was concluded that the level of erythrocyte arginase activity could be considered as a useful marker for assessing the level of mental retardation in children with Down syndrome.
Investigation of Blood Antioxidant Enzyme Levels and Glutathione Peroxidase, Catalase, and Superoxide Dismutase Gene Polymorphism in Sheep With Fluorosis
(int Soc Fluoride Research, 2017) Ozbey, Ulku; Deger, Yeter; Yur, Fatmagul; Cambay, Zafer; Ozbey, Gokben
Reactive oxygen species have been considered to play a significant part in the development of fluorosis, a critical public health issue in many parts of the world. OBJECTIVES: The aims of this study, conducted on two groups of sheep, with and without fluorosis, was (i) to determine the effect of fluorosis on antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and on malondialdehyde (MDA); and (ii) to investigate the relationship between the SOD, CAT, and GSH-Px genotypes and the antioxidant enzyme levels. METHODS: The two groups of sheep were: (i) 24 Akkaraman sheep with fluorosis living in Dogubeyazit province of Agri and (ii) 20 Akkaraman sheep with no signs of fluorosis living in Van. The MDA level and the antioxidant enzyme activities were identified spectrophometrically. The genotype characteristics were determined by the PCR-RFLP method using DNA extracted from blood. RESULTS: Compared to the control sheep without fluorosis, we found in the fluorotic sheep: (i) an increase in plasma MDA levels and GSH-Px-1 activity (p<0.05), and (ii) a decrease in SOD and CAT activities (p< 0.01). There were significant differences found in the genotype and allele frequencies in both groups (p<0.01). CONCLUSIONS: Fluoride-induced oxidative stress affected the membrane structure resulting in elevated erythrocyte MDA levels and reduced enzyme activity of the enzymes SOD and CAT. According to our data, the genepolymorphisms show a tendency towards fluorosis for our local sheep population.
Investigation of Differences in P53 Gene Polymorphisms Between Schizophrenia and Lung Cancer Patients in the Turkish Population
(Hindawi Ltd, 2011) Ozbey, Ulku; Yuce, Huseyin; Namli, Mustafa; Elkiran, Tamer
Objective. The reduced incidence of cancer observed in schizophrenia patients may be related to differences in genetic background. It has been suggested that genetic predisposition towards schizophrenia is associated with reduced vulnerability to lung cancer, and p53 gene is one of the candidate genes. In our study, we aimed to investigate polymorphisms in the BstUI in exon 4 and MspI in intron 6 restriction sites of the p53 gene in Turkish schizophrenia patients, lung cancer patients, and controls. Material and Methods. Allele and genotype incidence of these polymorphisms with their haplotype combinations were studied in 100 Turkish lung cancer and schizophrenia patients and 100 controls without malignant and schizophrenia diseases. The genotype characteristics were determined by PCR-based RFLP method using DNA extracted from peripheral blood. Results. For the BstUI and MspI polymorphism, there were found significant differences in the genotype and allele frequencies between schizophrenia and lung cancer patients with control groups (P < .01). The analysis based on haplotype frequencies showed the presence of BstUI-MspI 2-1 haplotype in cancer patients (12%) in contrast to the absence of this haplotype in schizophrenia and controls. Only in lung cancer patients we found both significant decrease of A1 allele of the p53 codon 72 (OR0.23, 95% CI 0.9-0.58) and A1/A1 homozygous genotype (P < .0001, OR0.19). Conclusion. The results of this study suggest a protective effect of A1 allele against lung cancer, and the p53 MspI polymorphism may modify the susceptibility to lung cancer as a single factor rather than in combination with BstUI polymorphism.
Oxidative Stress and Altered Levels of Antioxidants in Adolescents With Down Syndrome During Pre-Exercise and Post-Exercise
(Academic Journals, 2012) Ozbey, Ulku; Arslan, Cengiz; Savucu, Yuksel; Erisir, Mine; Seyran, Ayse
The aim of this study was to determine the influence of exercise on activity of erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and plasma malondialdehyde (MDA), beta-carotene, retinol levels in adolescents with Down syndrome (DS). Twenty adolescents with DS (14.86 +/- 7.07 years) performed a 12-week training program. Body composition was measured by bioelectric impedance method. SOD, GPx, CAT, MDA, retinol, beta-carotene levels was determined spectrophotometrically. When compared to baseline, MDA level was increased (P<0.05). SOD, GPx activities and beta-carotene level were decreased (P<0.05). There was no difference during pre-post exercise in terms of CAT activity and retinol level (P>0.05). The mean value of percentage of fat mass was reduced. Regular exercise decreased SOD, GPx activities and beta-carotene level and did not affect CAT activity and retinol level in individuals with DS. Exercise increases oxidative stress depending on level of training.
Oxidative Stress and Altered Levels of Oxidants and Antioxidants in Acute Ischemic Stroke Patients in a Region of East Turkey
(Drunpp-sarajevo, 2012) Ozbey, Ulku; Seyran, Ayse; Erisir, Mine; Ozel, Seda
Background and purpose: Ischemic stroke is one of the most important diseases causing severe disability and death. Hypertension is the most important risk factor in strokes, representing roughly 70% of all cases. Oxidative stress plays an important role in acute ischemic stroke (AIS) pathogenesis. It is believed to be one of the mechanisms taking part in neuronal damage in stroke. Free radical formation and subsequent oxidative damage may be a factor in stroke severity. In 28 patients with AIS and 28 healthy individuals were investigated with regard to relationship between ischemic-stroke and glutathione peroxidase (GSH-Px), catalase (CAT) activities, malondialdehyde (MDA), glutathione, beta-carotene, vitamin A levels. Methods: GSH-Px, CAT activities and MDA, GSH, vitamin A, beta-carotene levels were measured by spectrophotometry in 28 subject (15 females and 13 males aged 67.1 +/- 13.3years) with AIS and 28 age-matched healthy subjects (13 females and 15 males aged 65.9 +/- 10.1). Results: In the patients with acute ischemic stroke, GSH-Px activity and MDA, GSH, vitamin A levels were found increased (p<0.001). Whereas there was no significant difference in level of beta-carotene and CAT activity between AIS patients and control group (p>0.005). Conclusions: Our results suggest deleterious effects of oxidative stress on clinical outcome in AIS. There was a significant increase in levels of MDA, GSH-Px and GSH. GSH elevation seemed to be a part of adaptive mechanisms
The Relationship Between Blood Antioxidant Enzyme Levels and Genotype During Migraine Attack and Initial Periods in Migraine Patients
(Walter de Gruyter Gmbh, 2011) Ozbey, Ulku; Ozel, Seda; Seyran, Ayse; Erisir, Mine; Berilgen, M. Said
Objective: In recent years, researchers have been focused on the importance of oxidative stress on migraine pathogenesis. We aimed to investigate the roles of Superoxide Dismutase (SOD), Glutathione Peroxidase (GSH-Px), Catalase (CAT), antioxidant Glutathione (GSH) and Malondialdehyde (MDA) of a lipid peroxidation product in migraine pathogenesis. Furthermore, we also aimed to investigate the incidence of the gene polymorphisms of these enzymes in Turkish population. Material and Methods: GSH-Px, CAT, SOD activities and plasma MDA and blood GSH levels were measured in 40 migraine patients at attack and initial period and 40 healthy subjects. The genotype characteristics were determined by PCR-based RFLP method using DNA extracted from peripheral blood. Results: Statistically significant decrease in GSH-Px, CAT, SOD activities and GSH levels were found in the migraine patients compared to the control group (GSH, CAT p < 0.001; GSH-Px, SOD p < 0.05). In the migraine patients and control groups no significant differences were observed for Mn-SOD and CAT genotypes, but there was a significant difference in the GSH-Px3 genotype. No difference was detected in the allele frequencies of MnSOD, GSH-Px3 and CAT gene between the patients and control group. Conclusion: Consequently, oxidative stress and antioxidant enzymes may play an important role in migraine pathogenesis, and according to our data GSH-Px3 gene polymorphism may cause a tendency to migraine for our regional community. Conflict of Interest: There is no conflict of interest between autors.