Browsing by Author "Erel, Ozcan"

Now showing 1 - 10 of 10

The Effect on Serum Myeloperoxidase Activity and Oxidative Status of Eradication Treatment in Patients Helicobacter Pylori Infected
(Pergamon-elsevier Science Ltd, 2011) Nazligul, Yasar; Aslan, Mehmet; Horoz, Mehmet; Celik, Yilmaz; Dulger, Ahmet Cumhur; Celik, Hakim; Erel, Ozcan
Objectives: Myeloperoxidase activity has been investigated after eradication of Helicobacter pylon (H. pylori) in infected patients in previous studies but the results are controversial. The aim of this study was to investigate effect on serum myeloperoxidase activity and oxidative status of eradication treatment in H. pylon-infected patients. Design and methods: Gastric biopsy specimens were obtained from 30 H. pylori infected patients. Serum Myeloperoxidase activity was measured by enzyme-linked immunoassay. Oxidative status was determined using total antioxidant capacity (TAC) and total oxidant status (TOS) measurement and calculation of oxidative stress index (OSI). Results: After 2 weeks of the eradication treatment, serum myeloperoxidase activity, TOS and OSI values were significantly lower (all: p<0.001), while TAC was significantly higher (p<0.001). Conclusions: Our results indicate that eradication treatment in H. pylori-infected patients may affect both oxidative stress and myeloperoxidase activity which is an important biomarker in pathogenesis of atherosclerosis. (C) 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
The Evaluation of Maternal Systemic Thiol/Disulphide Homeostasis for the Short-Term Prediction of Preterm Birth in Women With Threatened Preterm Labour: a Pilot Study
(Taylor & Francis inc, 2022) Cetin, Orkun; Karaman, Erbil; Alisik, Murat; Erel, Ozcan; Kolusari, Ali; Sahin, Hanim Guler
The aim of this study was to investigate maternal systemic thiol/disulphide homeostasis (TDH) for the short-term prediction of preterm birth in women with threatened preterm labour (TPL). This prospective study included 75 pregnant women whose pregnancies were complicated by TPL. Thirty-seven of them delivered within 7 days and 38 of them delivered beyond 7 days. Maternal serum samples were collected at the day of diagnosis and the TDH was measured. The maternal disulphide level was significantly higher in pregnant women who delivered within 7 days (25.0 +/- 9.8 mu mol/L vs 19.4 +/- 9.8 mu mol/L, p: .015). The threshold value of 22.1 mu mol/L for maternal disulphide level predicted delivery within 7 days with 62.2% sensitivity and 60.5% specificity (area under curve 0.651, confidence interval 0.53-0.78). The likelihood ratios for short cervix (<= 25 mm) and maternal disulphide level (>= 22 mu mol/L) to predict delivery within 7 days was found to be 8.7 and 7.3, respectively. The likelihood ratio of combining two tests to predict delivery within 7 days was found to be 11.4. The maternal TDH, which is an indicator of oxidative stress status in maternal compartment, is disturbed in TPL cases who delivered within 7 days. Elevated maternal disulphide level along with cervical length screening predicts a short latency period in pregnancies with TPL. IMPACT STATEMENT What is already known on this subject? Spontaneous preterm delivery is one of the major complication of pregnancy and the common cause of neonatal morbidity and mortality. Threatened preterm labour (TPL) is also a frequent complaint in obstetric emergency care units in all around the world. Triaging women with TPL is mandatory for planning further management therapies, since the most of them will eventually deliver at term. Only the measurement of cervical length in symptomatic women has moderate accuracy in predicting preterm delivery. Short cervix is described as an independent predictor of preterm delivery in women with TPL, its predictive accuracy as a single measurement is relatively limited. On this account, several potential markers like foetal fibronectin in the cervicovaginal fluid, salivary oestriol, prolactin in vaginal discharge, maternal serum calponin and interleukin-6 in the amniotic fluid were examined to predict preterm delivery in previous studies. However, none of them represented an excessive predictive accuracy like high sensitivity, PPV or NPV. What do the results of this study add? We report a method which has higher diagnostic and predictive performance to identifying TPL women with high risk of preterm delivery. According to the current literature, there are accumulated data about the correlation between oxidative stress (OS) and preterm delivery regardless of the amniotic membrane status. However, it is still debated whether OS is a trigger or a consequence of preterm delivery. Our study provides evidence for the first time that maternal serum thiol/disulphide homeostasis, which is an indicator of OS in maternal compartment, is disturbed in TPL cases who delivered within 7 days. The high disulphide level in maternal serum, along with cervical length measurement (short cervix) accurately predicts a short latency period in TPL cases. What are the implications of these findings for clinical practice and/or further research? This novel test combination (maternal serum disulphide level and cervical length measurement) could be used clinically to triage pregnant women presenting with TPL, avoiding overtreatment, unnecessary hospitalisations and increased medical costs. The future research would be addressed on reducing maternal OS by using new antioxidant treatment strategies to improve perinatal and long-term childhood outcomes.
Evaluation of Oxidant and Antioxidant Status in Infants With Hyperbilirubinemia and Kernicterus
(Sage Publications Ltd, 2011) Dogan, Murat; Peker, Erdal; Kirimi, Ercan; Sal, Ertan; Akbayram, Sinan; Erel, Ozcan; Tuncer, Oguz
Objective: The objective of the present study was to determine oxidant and antioxidant status in infants with hyperbilirubinemia and/or kernicterus and to find whether there is a relationship between bilirubin level and oxidant/antioxidant status. Patients: The study includes 69 full-term newborns (neonates with hyperbilirubinemia needing phototherapy [Group 1, n = 36] and neonates with kernicterus [Group 2, n = 33]) and 25 age-matched healthy newborn. Results: Plasma total antioxidant capacity (TAC) and serum total oxidant status (TOS) were significantly higher in Groups 1 and 2 than the control group. There was a significant difference between Group 1 and control cases for malondialdehyde (MDA; p < 0.001). Total free sulfhydryl group (TTHI) values were significantly elevated in Group 1 compared to Group 2 and control cases. Correlation analysis showed that the correlation between total bilirubin (TB) and TAC, TOS, MDA and oxidative stress index may be expressed by a quadratic curve. After phototherapy, a statistically significant increase in nitrite level was observed. Conclusion: We demonstrated that the relationship between serum TB and antioxidants and oxidative stress could be expressed by a quadratic correlation curve.
Impairment of Thiol-Disulfide Homeostasis in Preeclampsia
(Taylor & Francis Ltd, 2016) Korkmaz, Vakkas; Kurdoglu, Zehra; Alisik, Murat; Cetin, Orkun; Korkmaz, Hilal; Surer, Hatice; Erel, Ozcan
Aim: To investigate the effects of severity of preeclampsia on thiol-disulfide homeostasis (TDH).Material and methods: A total of 108 participants were divided into three groups: Group 1 was composed of pregnant women with no obstetric complications, Group 2 included pregnant women with mild preeclampsia, and Group 3 consisted of pregnant women with severe preeclampsia. TDH parameters were determined, and comparisons of clinical and routine laboratory test findings were made in all groups.Results: The serum native thiol level was 347.927.4 in the control group, 237.2 +/- 44.2 in the mild preeclampsia group, and 227.9 +/- 53.1 in the severe preeclampsia group (p<0.001). The serum total thiol level was 376.1 +/- 31.9 in the control group, 261.8 +/- 49.4 in the mild preeclampsia group, and 248.3 +/- 57.4 in the severe preeclampsia group (p<0.001). The disulfide level was 14.1 +/- 5.6 in the control group, 12.3 +/- 5.1 in the mild preeclampsia group, and 10.2 +/- 4.8 in the severe preeclampsia group (p=0.001). A significant correlation between impairment in degree of TDH and severity of preeclampsia was observed.Conclusion: TDH was impaired in women with preeclampsia, and this impairment increased with disease severity. Therefore, impaired TDH may have a role in the etiopathogenesis of the disease.
Maternal Serum Thiol/Disulfide Homeostasis in Pregnancies Complicated by Neural Tube Defects: Report of a Preliminary Study
(Taylor & Francis Ltd, 2017) Karaman, Erbil; Cetin, Orkun; Boza, Baris; Alisik, Murat; Erel, Ozcan; Cim, Numan; Sahin, Hanim Guler
Objective: To determine and evaluate the maternal serum thiol/disulfide homeostasis in pregnancies complicated by neural tube defects (NTD) via a novel method.Methods: Seventy-three pregnant women with NTD (study group) and seventy-one healthy control pregnant women (control group) were included in the study. A new and fully automated method was used to measure plasma native thiol, total thiol and disulfide levels, based on the reduction of dynamic disulfide bonds to functional thiol groups by sodium borohydrate.Results: The study and control groups were gestational age-matched. There were no statistical differences in demographic variables regarding age, gravidity, parity and body mass index. The serum native thiol levels (-SH) were 360.550.3 and 353.3 +/- 31.0mol/l in study and control groups, respectively, which was not statistically different (p=0.308). The native thiol/total thiol, disulfide/native thiol and disulfide/total thiol ratios were not statistically significantly different (p>0.05).Conclusion: Our preliminary results show that maternal serum thiol/disulfide homeostatis does not change in pregnancies complicated by NTD. Larger further studies are required to evaluate the relation of oxidative stress and development of NTD.
The Maternal Serum Thiol/Disulfide Homeostasis Is Impaired in Pregnancies Complicated by Idiopathic Intrauterine Growth Restriction
(Taylor & Francis Ltd, 2018) Cetin, Orkun; Karaman, Erbil; Boza, Baris; Cim, Numan; Alisik, Murat; Erel, Ozcan; Sahin, Hanim Guler
Purpose: To investigate the maternal serum thiol/disulfide homeostasis in pregnancies complicated by idiopathic intrauterine growth restriction (IUGR) and to compare the results with healthy pregnancies.Materials and methods: This descriptive cohort study included 55 pregnant women complicated by idiopathic IUGR and 57 similar gestational aged healthy pregnant women in the third trimester of gestation. Maternal serum samples were collected at the day of diagnosis and the thiol/disulfide homeostasis was measured by using an automated assay method. The patients were followed up until delivery and perinatal outcomes were recorded.Results: Maternal serum native thiol (308.140.7mol/L vs. 282.4 +/- 60.6mol/L) and total thiol (346.8 +/- 48.1mol/L vs. 324.0 +/- 62.2mol/L) concentrations were significantly lower in IUGR group compared with healthy controls (p: .010 and p: .032, respectively), whereas disulfide (19.3 +/- 8.7mol/L vs. 20.8 +/- 7.8mol/L) concentrations were similar between the groups (p: .350). Maternal serum disulfide/native thiol and disulfide/total thiol ratios were higher in IUGR group compared with healthy controls (p: .014 and p: .017, respectively), whereas native thiol/total thiol ratio was significantly lower in IUGR group compared with healthy controls (p: .016).Conclusions: This study suggests that there is an impaired maternal thiol/disulfide homeostasis in pregnancies complicated by idiopathic IUGR during the third trimester of gestation.
The Maternal Thiol/Disulfide Homeostasis Does Not Change in Pregnancies Complicated by Preterm Prelabor Rupture of Membranes
(Taylor & Francis Ltd, 2018) Cetin, Orkun; Karaman, Erbil; Boza, Baris; Cim, Numan; Erel, Ozcan; Alisik, Murat; Sahin, Hanim Guler
Purpose: To evaluate the maternal thiol/disulfide homeostasis in pregnant women complicated by preterm prelabor rupture of membranes (PPROM) and to compare the results with healthy pregnancies. Materials and methods: This cohort study consisted of thirty-nine pregnancies complicated by PPROM and 44 gestational age-matched healthy pregnancies in the third trimester of gestation. Maternal serum samples were obtained at the day of diagnosis, and thiol/disulfide profiles were measured by using an automated assay method. The patients were followed till delivery, and perinatal outcomes were noted. Results: The maternal native thiol (319.9 +/- 30.5 mu mol/L versus 305.1 +/- 49.2 mu mol/L, p:.100), total thiol (379.2 +/- 38.8 mu mol/L versus 363.6 +/- 56.4 mu mol/L, p: .142) and disulfide (29.7 +/- 11.7 mu mol/L versus 29.3 +/- 10.1 mu mol/L, p: .864) levels were similar between the groups. Maternal disulfide/native thiol, disulfide/total thiol and native thiol/total thiol ratios were similar between the groups (p: .610, p: .565 and .562, respectively). The maternal serum thiol/disulfide profiles were not significantly correlated with maternal serum C-reactive protein, white blood cell count values and ongoing pregnancy outcomes (p>.05). Conclusions: The current study demonstrated that there was not any disturbance in maternal thiol/disulfide homeostasis in pregnancies complicated by PPROM at the time of initial diagnosis. Follow-up studies with larger sample size are needed to confirm our results.
Relationship Between Maternal Blood Ceruloplasmin Level, Catalase and Myeloperoxidase Activity and Neural Tube Defects
(Via Medica, 2017) Cetin, Orkun; Karaman, Erbil; Boza, Baris; Cim, Numan; Alisik, Murat; Erel, Ozcan; Sahin, Guler Hanim
Objectives: The exact pathogenesis of neural tube defects (NTDs) is poorly understood. We aimed at evaluating maternal anti-oxidant capacity (ceruloplasmin level, myeloperoxidase and catalase activity) in pregnancies complicated by NTDs. Material and methods: Fifty-four mothers with NTD-affected pregnancies and 61 healthy mothers, matched for gestational age, were recruited. Maternal venous blood samples were obtained after detailed fetal ultrasound examination to measure myeloperoxidase, catalase activity and ceruloplasmin levels. The clinical characteristics of all participants were collected. Results: Maternal blood catalase activity was significantly lower in the study group (117.1 +/- 64.8 kU/L) as compared to controls (152.2 +/- 110.6 kU/L) (p = 0.044). Maternal blood ceruloplasmin levels were also significantly lower in the study group (180.5 +/- 37.7 U/L) as compared to controls (197.9 +/- 35.9 U/L) (p = 0.012). Myeloperoxidase activity was similar in both groups (112.6 +/- 22.2 U/L vs. 113.6 +/- 38.1 U/L) (p = 0.869). Conclusions: In the present study, maternal blood ceruloplasmin level and catalase activity were found to be lower in NTD-affected pregnancies as compared to healthy controls. Thus, it seems safe to conclude that impaired antioxidant capacity may play a role in the development of NTDs during pregnancy, in addition to the genetic, environmental and metabolic factors.
Relationship Between Thiol-Disulfide Balance and Idiopathic Sudden Sensorineural Hearing Loss
(Assoc Brasileira Otorrinolaringologia & Cirurgia Cervicofacial, 2022) Cetin, Yaser Said; Bozan, Nazim; Avci, Koray; Aslan, Mehmet; Erel, Ozcan
Introduction: Impaired cochlear perfusion is a major etiological factor in idiopathic sudden sensorineural hearing loss. Oxidative stress has been shown to be a risk factor for oxidative damage. Objectives: We investigated the role of oxidative stress in idiopathic sudden sensorineural hearing loss by comparing serum levels of oxidant and antioxidant molecules including thiol/disulfide homeostasis paraoxonase, stimulated thiol/disulfide homeostasis paraoxonase, arylesterase, ceruloplasmin and myeloperoxidase in patients who did and did not recover after treatment. Methods: The amount of dynamic disulfide was calculated by determining half of the difference between the total thiols and native thiols. After the determination of native, total thiol, and disulfide amounts, the disulfide/total thiol percent ratio, native thiol/total thiol ratio and disulfide/native thiol percent ratio were calculated and then compared between the two groups. Additionally, clinical relationship between audiological recovery and native thiol, disulfide, disulfide/native thiol percent ratio, and disulfide/total thiol percent ratio levels was investigated. Blood samples were also analyzed for the assessment of thiol/disulfide homeostasis paraoxonase, stimulated thiol/disulfide homeostasis paraoxonase, arylesterase, ceruloplasmin, and myeloperoxidase levels. Results: A significant difference was found between the two groups with regard to total oxidant status disulfide, disulfide/native thiol percent ratio, disulfide/total thiol percent ratio, and native thiol/total thiol ratio levels (p = 0.001, p = 0.001, p = 0.001, p = 0.003, p = 0.001, p = 0.002, respectively). However, no significant difference was found between the two groups with regard to thiol/disulfide homeostasis paraoxonase, stimulated thiol/disulfide homeostasis paraoxonase, ceruloplasmin, and myeloperoxidase levels (p > 0.05 for all). Conclusion: The results supported the common hypothesis that vascular pathologies are the primary cause of idiopathic sudden sensorineural hearing loss and that other etiological factors ultimately result in vascular pathologies. The oxidant-antioxidant and thiol-disulfide balances were impaired in the idiopathic sudden sensorineural hearing loss group.
Thiol/Disulfide Homeostasis as a Novel Indicator of Oxidative Stress in Obstructive Sleep Apnea Patients
(Wiley, 2017) Dinc, Mehmet Emre; Ozdemir, Cengiz; Ayan, Nilhan Nurlu; Bozan, Nazim; Ulusoy, Seckin; Koca, Cemile; Erel, Ozcan
Objectives: The aim of the present study was to assess thiol/disulfide (SS) homeostasis as a novel indicator of oxidative stress in patients with obstructive sleep apnea (OSA) and to investigate the effect of continuous positive airway pressure (CPAP) therapy on oxidative parameters. Study Design: Prospective clinical study. Methods: A total of 104 subjects, 44 in an OSA group and 60 in two control groups (control simple snoring group, control OSA group) were included. The levels of parameters were measured using the Erel and Neselioglu method in patients with moderate or severe OSA before and after CPAP therapy. Results: The serum native thiol (SH) and total SH levels as well as the % SH/total SH ratio were significantly lower (P < 0.05) in OSA patients compared to controls, and the SS level and % SS/SH and % SS/total SH ratios were significantly higher (P < 0.05). After CPAP therapy, the native SH level and % SH/total SH ratio were significantly higher (P < 0.05) than before CPAP therapy, and the SS level and % SS/SH and % SS/total SH ratios were significantly lower (P < 0.05). Significant negative correlations were evident between the apnea/hypopnea index (AHI) and the native SH level and % SH/total SH ratio (P < 0.05) before CPAP therapy; and significant positive correlations were seen between the AHI and the % SS/SH and % SS/total SH ratios but not with the SS level. Conclusion: We found that oxidative stress was increased and CPAP therapy had a positive effect in patients with moderate or severe OSA.