Okan Ozkaya
Süleyman Demirel University
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Featured researches published by Okan Ozkaya.
Strahlentherapie Und Onkologie | 1999
Hakan Kaya; Namik Delibas; Mustafa Serteser; Engin Ulukaya; Okan Ozkaya
BackgroundBecause radiotherapy is one of the causes of primary or secondary ovarian failure, protection of ovarian functions in the patients receiving total body or pelvic radiotherapy is of importance. In this study, we investigated the role of melatonin in the oxidative damage in both whole body and ovaries, which is caused by radiotherapy.Materials and MethodsEighteen female rats were divided into 3 groups, each of which consisted of 6 rats. First group was control group receiving no treatment, second group received total body radiotherapy (RT) by 2 × 360 cGy only and third group received radiotherapy plus melatonin. Malondialdehyde (MDA) levels in both blood and ovarian tissue were detected as the indicator of free radical (FR) damage. Levels of erythrocyte superoxide dismutase (SOD) and glutathion peroxidase (GPX) in blood were measured as the indicators of antioxidant level.ResultsRadiotherapy caused a significant increase in the levels of MDA in blood and ovarian tissue (p < 0.001). However, MDA levels decreased in the radiotherapy plus melatonin group (p < 0.05). SOD and GPX levels decreased insignificantly in the radiotherapy only group while they increased in the radiotherapy plus melatonin group significantly (p < 0.01 and p < 0.05, respectively).ConclusionMelatonin, in rats, reduced the level of MDA, which is elevated by radiotherapy and increased the levels of SOD and GPX, which are involved in the antioxidant system.ZusammenfassungZielDa die Strahlentherapie eine der Ursachen der primären bzw. sekundären Ovarialinsuffienz ist, ist es wichtig, die ovariellen Funktionen der Patienten, die einer Beckenoder Gesamtkörperstrahlentherapie unterzogen werden, zu schützen. In dieser Studie untersuchten wir daher, ob Melatonin in der Lage ist, die oxidative Schädigung sowohl des Gesamtkörpers als auch der Eierstocke durch Strahlentherapie zu verringern.Material und Methode18 weibliche Ratten wurden in drei Gruppen unterteilt, von denen jede aus sechs Ratten bestand. Die erste Gruppe war die unbehandelte Kontrollgruppe, die zweite Gruppe empfing nur eine Strahlentherapie von 2mal 360 cGy, und die dritte Gruppe wurde strahlentherapiert und erhielt Melatonin (Radiotherapie + Melatonin). Der Gehalt an Malondialdehyd (MDA) im Blut und ovariellen Gewebe wurde als Indikator für die Schädigung durch freie Radikale bestimmt. Die Bestimmung von Superoxiddismutase (SOD) und von Glutathionperoxidase (GPX) diente als Indikator des antioxidativen Status.ErgebnisseStrahlentherapie verursachte eine bedeutende Zunahme des Gehalts von MDA im Blut und im ovariellen Gewebe (p < 0,001). In der Gruppe der Tiere, die Strahlentherapie und Melatonin erhielten, waren die MDA-Werte signifikant erniedrigt (p < 0,05), SOD und GPX waren in der Gruppe 2 (Radiotherapie) unverandert gegenüber der Kontrolle und erhöhten sich signifikant in der Gruppe 3 (Radiotherapie + Melatonin), (p < 0,01 für SOD und < 0,05 für GPX).SchlußfolgerungenMelatonin verringert bei Ratten den Gehalt an MDA nach Strahlentherapie und erhöht zudem den Gehalt an SOD und GPX, welche antioxidativ wirken.
Journal of Obstetrics and Gynaecology Research | 2007
Mekin Sezik; Okan Ozkaya; Fuat Demir; Hulya Toyran Sezik; Hakan Kaya
Aim: To investigate the short‐ and medium‐term consequences of performing total salpingectomy during abdominal hysterectomy (without oophorectomy) on certain ovarian reserve parameters and blood flow velocity measurements through the ovarian stroma.
British Journal of Obstetrics and Gynaecology | 2000
Hakan Kaya; Baha Oral; Ralf Dittrich; Okan Ozkaya
Objective To determine oxygen free radical activity in breech presentation at birth and relate it to umbilical cord blood acid‐base status.
Journal of The American Association of Gynecologic Laparoscopists | 2002
Hakan Kaya; Yasemin Babar; Sadik Ozmen; Okan Ozkaya; Mehmet Karci; Ali Riza Aydin; Demir Ozbasar
STUDY OBJECTIVE To investigate whether frequency of persistent ectopic pregnancy after linear salpingotomy can be reduced by prophylactic administration of a single intraoperative injection of local methotrexate. DESIGN Prospective, randomized, controlled trial (Canadian Task Force classification I). SETTING University-affiliated hospital. PATIENTS Sixty-five women with unruptured ectopic pregnancy. INTERVENTION Laparoscopic salpingotomy with or without a single intratubal dose of methotrexate 1 mg/kg. MEASUREMENTS AND MAIN RESULTS In the prophylaxis group, 22 patients received a single dose of intratubal methotrexate 1 mg/kg after linear salpingotomy; 43 controls had only linear salpingotomy. Six women (14%) in the control group developed persistent ectopic pregnancy, compared with none in the prophylaxis group (p <0.05). CONCLUSION In our opinion, intratubal methotrexate injection during laparoscopic salpingotomy is a practical option for women with unruptured ectopic pregnancy.
Journal of Obstetrics and Gynaecology Research | 2005
Okan Ozkaya; Mekin Sezik; Hakan Kaya; Raziye Desdicioglu; Ralf Dittrich
Aim: To compare vaginally administered misoprostol to rectally administered misoprostol and placebo in a prospective randomized placebo‐controlled study.
Journal of Obstetrics and Gynaecology Research | 2010
Demir Ozbasar; Ummuhan Toros; Okan Ozkaya; Mekin Sezik; Hafize Uzun; Habibe Genc; Hakan Kaya
Aim: We prospectively aimed to investigate the relationship between raloxifene administration and serum malondialdehyde (MDA), nitric oxide (NO), high‐density lipoprotein (HDL), low‐density lipoprotein (LDL), and triglyceride levels in postmenopausal women undergoing hemodialysis treatment for chronic renal failure.
European Journal of Obstetrics & Gynecology and Reproductive Biology | 2012
Mekin Sezik; Meltem Antalyalı; Ozlem Ozmen; Mehmet Haligur; Afsin Koker; Okan Ozkaya; Muhammet Kosker
OBJECTIVE To evaluate the effects of intra-amniotic (IA) and fetal injections of a single ultra-high dose of betamethasone (BM) 48 h before preterm delivery on neonatal pulmonary function, using an experimental goat model. STUDY DESIGN Eighteen date-mated singleton pregnant Hair goats were randomized into four groups. At gestational day 118 (alveolar phase, term 150-155 days) after obtaining a sample of amniotic fluid, fetuses in group 1 (n=5) received 8 mg/kg IA BM, and in group 2 (n=5) 4 mg/kg fetal IM BM. In group 3 (n=4) (0.3mg/kg/day) maternal BM was administered at day 118 and 119 with a 24h interval; control fetuses (n=4) received 1 mL/kg of IA saline at day 118. At gestational day 120, after obtaining second sample of amniotic fluids 18 kids were delivered by preterm cesarean section, entubated, weighed, and mechanically ventilated for 15 min. Arterial blood gas samples and deflation/inflation lung pressure-volume measurements were obtained. After sacrifice, lungs were removed, weighed, gross examined and processed for further histological and immunohistochemical (IHC) evaluations. On hematoxylin and eosin (HE) stained slides, presence and severity of lung emphysema was evaluated; slides stained for surfactant proteins, and caspases were used for semi-quantitative evaluation of lung maturation. Kruskal-Wallis, Mann-Whitney, Wilcoxon signed rank, and chi-square tests were used for comparisons. RESULTS IA BM was associated with increased number of stillbirths (60% vs. 0% in control) (p=0.06) and emphysematous changes. Bodyweight-adjusted pressure-volume measurements were improved after maternal, but not IA or fetal, BM (p=0.06). Following mechanical ventilation, arterial blood gas parameters did not significantly alter across maternal and fetal administrations. However, pH was significantly lower (p<0.05) and carbon dioxide partial pressure was higher (p<0.05) in the control group, indicating hypercapnic acidemia in non-treated pregnancies. None of the treatments induced measurable alterations in amniotic fluid lecithin/sphingomyelin (L/S) values. IA and fetal routes were associated with decreased surfactant protein expressions and increased apoptotic activity in alveolar and bronchio-alveolar epithelial cells. CONCLUSION Ultra-high dose IA and fetal IM BM is not superior to the standard dose and maternal way of administration in our experimental design.
Journal of Obstetrics and Gynaecology Research | 2006
Mekin Sezik; Okan Ozkaya; Hulya Toyran Sezik; Elif Gül Yapar; Hakan Kaya
Aim: To assess the consequences of consanguineous unions between first cousins on the severity of pre‐eclampsia and associated perinatal morbidity.
Journal of Perinatal Medicine | 2006
Okan Ozkaya; Mekin Sezik; Hulya Toyran Sezik; Elif Gül Yapar Eyi
Abstract In an effort to better define preeclamptic women at risk of eclampsia, we examined the predictive value of maternal demographic characteristics and admission maternal laboratory values for the risk of subsequent development of eclampsia in preeclamptic women, who were not receiving magnesium sulfate during hospitalization. The decision to use magnesium sulfate prophylaxis was at the discretion of the treating physician. Preeclamptic women admitted throughout a 3-year period and treated with a protocol exempting magnesium sulfate therapy were retrospectively included (n=497). Maternal data at admission were recorded and analyzed. Eight women developed an eclamptic seizure during subsequent hospital follow-up. Logistic regression models were used to assess the independent predictive role of each variable on the development of eclampsia. Lower serum fibrinogen values, increased leukocyte counts, and increased diastolic blood pressure at admission were independent predictors of a subsequent in-hospital eclamptic seizure. An initial diastolic blood pressure ≥120 mm Hg, blood leukocyte count >16,000/μL, and serum fibrinogen value <450 mg/dL were associated with a 25.4-, 7.1-, and 26.6-fold increased risk of eclampsia, respectively. We conclude that marked leukocytosis and diastolic blood pressure increment might precede the development of eclampsia. Serum fibrinogen concentrations >450 mg/dL seem to be protective for eclampsia. The association between inflammation and eclampsia merits further investigation.
Journal of Obstetrics and Gynaecology Research | 2004
Hakan Kaya; Mehmet Karci; Okan Ozkaya; Mekin Sezik
Aim: To investigate the prognostic significance of hysterosalpingography carried out before one‐sided gamete intrafallopian transfer for unexplained infertility.