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Featured researches published by Onder Celik.


International Journal of Infectious Diseases | 2010

Prevalence and antibiotic susceptibility of Mycoplasma hominis and Ureaplasma urealyticum in pregnant women

Mehmet Refik Bayraktar; Ibrahim Halil Ozerol; Nilay Gucluer; Onder Celik

BACKGROUND Mycoplasma hominis and Ureaplasma urealyticum are important opportunistic pathogens implicated in urogenital infections and complicated pregnancy. We aimed to study the role of these pathogens in symptomatic and asymptomatic pregnant women and determine their clinical significance and antibiotic susceptibility. METHODS One hundred pregnant women were included in the study, 50 symptomatic patients and 50 asymptomatic controls. Duplicate endocervical samples were taken from each individual and analyzed using the Mycoplasma IST-2 kit and A7 agar medium. Antimicrobial susceptibility was tested against doxycycline, josamycin, ofloxacin, erythromycin, tetracycline, ciprofloxacin, azithromycin, clarithromycin, and pristinamycin using the Mycoplasma IST-2 kit. RESULTS Twelve symptomatic pregnant women had spontaneous abortions. Of these, eight (66.7%) cases had been colonized with M. hominis and/or U. urealyticum. Of the pregnant women infected with M. hominis and/or U. urealyticum, 40.7% delivered a low birth weight infant. M. hominis was successfully cultured in five women (5%) and U. urealyticum in 27 (27%). Among positive cultures, 15.6% and 84.4% of isolates were M. hominis and U. urealyticum, respectively. M. hominis and U. urealyticum were uniformly susceptible to doxycycline, tetracycline, and pristinamycin, which may be successfully used in the empirical therapy of infected individuals. CONCLUSIONS It can be concluded that genital colonization with M. hominis and U. urealyticum may predispose to spontaneous abortion and low birth weight.


Human Reproduction | 2008

Reply: Combating endometriosis by blocking proteasome and nuclear factor-κB pathways

Onder Celik; Seyma Hascalik; Koray Elter; M.E. Tagluk; Bilgin Gurates; Nasuhi Engin Aydin

BACKGROUND The objective of this study is to investigate the effect of pyrrolidine dithiocarbamate [PDTC; a nuclear factor-kappaB (NF-kappaB) inhibitor] and bortezomib (Velcade; a proteasome inhibitor) on the development of experimental endometriotic implants in rats. METHODS Endometriosis was surgically induced in 30 rats using the method of Vernon and Wilson. Three weeks later the viability and volume of the implants were recorded and classified. Afterwards, rats were put into three groups with equal numbers. The groups were labelled as the control, the PDTC and the bortezomib groups. Seven days after treatment, a third laparotomy was done and the volume of implants was measured again. The animals were then sacrificed, and the implants were stained with Ki67, proliferating cell nuclear antigen (PCNA), CD34, CD31 and Massons trichrome histochemical staining. RESULTS In 80% of the implanted rats, vesicles at the suture region were observed, and the rats graded according to average vesicle diameter (D) as: Grade 1 (no vesicle, 20% of rats), Grade 2 (D < 2 mm, 33.3% of rats), Grade 3 (2 mm 4.5 mm, 26.7% of rats) and Grade 4 (D > 4.5 mm, 20% of rats). After treatment with PDTC or bortezomib, these percentages were decreased for Grades 3 and 4, and increased in Grade 1. The post-treatment implant volumes were decreased in the PDTC and bortezomib groups (P < 0.002 and P < 0.001), and slightly increased in the control group (P = 0.279). In the PDTC and bortezomib groups, CD34, CD31, PCNA and Ki67 expression levels were similar but were significantly reduced compared with the control group. CONCLUSIONS PDTC and bortezomib may represent a novel therapeutic strategy for treatment of endometriosis.


Journal of Pineal Research | 2004

Melatonin reduces torsion-detorsion injury in rat ovary: biochemical and histopathologic evaluation

Yusuf Turkoz; Onder Celik; Seyma Hascalik; Yilmaz Cigremis; Mehmet Hascalik; Bulent Mizrak; Saim Yologlu

Abstract:  This experimental study was designed to determine the effects of melatonin on the levels of malondialdehyde (MDA), reduced glutathione (GSH), xanthine oxidase (XO) after adnexial torsion/detorsion (ischemia/reperfusion, I/R) of the ovaries of in rats. Forty adult albino rats were divided into five groups: sham operation, torsion, I/R plus saline, I/R plus melatonin and torsion plus melatonin. Rats in the sham‐operated group underwent a surgical procedure similar to the other groups but the adnexa was not occluded. Rats in the torsion group were killed after adnexal torsion for 3 hr. Melatonin and saline were injected intraperitoneally (10 mg/kg) 30 min before detorsion to the I/R plus melatonin group and I/R plus saline group respectively. After 3 hr of ovarian detorsion, the rats were killed and ovaries were removed. Melatonin was injected intraperitoneally (10 mg/kg) 30 min before torsion to the torsion plus melatonin group. After 3 hr of ovarian torsion, the rats were killed and ovaries were harvested. The tissue levels of MDA, GSH and XO were measured. MDA and XO levels in the I/R plus saline group increased significantly when compared with torsion and sham‐operated groups (P < 0.001). MDA and XO levels in the I/R plus melatonin group were lower than I/R plus saline and differences between the two groups were statistically significant (P < 0.001). GSH levels in the I/R plus saline group decreased significantly when compared with ischemia and sham‐operated groups (P < 0.001). GSH levels in the I/R plus melatonin treated rats were significantly higher than I/R plus saline and ischemia groups (P < 0.001). The tissue levels of XO, MDA and GSH were similar between ischemia and ischemia plus melatonin groups. Morphologically, polymorphonuclear neutrophil infiltration and vascular dilatation were obvious in the I/R‐damaged ovaries, and the changes also partially reversed by melatonin. This study demonstrates that melatonin protects the ovaries against oxidative damage associated with reperfusion following an ischemic insult.


Gynecologic and Obstetric Investigation | 2004

Resveratrol, a Red Wine Constituent Polyphenol, Protects from Ischemia-Reperfusion Damage of the Ovaries

Seyma Hascalik; Onder Celik; Yusuf Turkoz; Mehmet Hascalik; Yilmaz Cigremis; Bulent Mizrak; Saim Yologlu

Objective: The aim of this study is to investigate the effects of resveratrol on histopathological changes, antioxidant status and lipid peroxidation, in torsion-detorsion injury in rat ovaries. Method: To determine whether ischemia followed by reperfusion can induce ovarian oxidative damage, we created a model of adnexal ischemia-reperfusion by using rats. Ischemia was induced by unilateral occlusion of the tubo-ovarian vessels for 3 h. Reperfusion was achieved by releasing the occlusion and restoring the circulation for 3 h. Thirty-two adult female albino rats were divided equally into 4 groups: sham operation, torsion, saline/detorsion and resveratrol/detorsion. Rats in the torsion group were killed after 360° clockwise adnexal torsion for 3 h. Resveratrol was injected intraperitoneally 30 min before detorsion in the resveratrol/detorsion group, and saline was administered in the saline/detorsion group. After 3 h of adnexal detorsion in both of these groups, the rats were killed and adnexa were removed. The tissue levels of malondialdehyde, reduced glutathione and xanthine oxidase activity were measured. Results: Malondialdehyde and xanthine oxidase levels in the saline/detorsion group were increased significantly when compared to the torsion and sham operation groups (p < 0.001). Malondialdehyde levels in the resveratrol group were lower than in the saline/detorsion group, and differences between the two groups were statistically significant (p < 0.001). Xanthine oxidase levels in the resveratrol group were lower than in the saline/detorsion and torsion groups, and differences between these groups were statistically significant (p < 0.001). Reduced glutathione levels in the saline/detorsion group were decreased significantly when compared to the torsion and sham operation groups. Reduced glutathione levels in the resveratrol group were significantly higher than in the saline/detorsion group (p < 0.006). Histological examination showed a significant improvement in ovarian morphology in the resveratrol-treated rats compared with the ischemia and ischemia-reperfusion groups. Conclusion: Our results demonstrated that intraperitoneal resveratrol administration reduced the lipid peroxidation products of ischemic rats and ovarian damage was reduced as indicated by histological examination.


Journal of Perinatal Medicine | 2013

Maternal and fetal adropin levels in gestational diabetes mellitus

Ebru Celik; Ercan Yilmaz; Onder Celik; Mustafa Ulas; Ilgin Turkcuoglu; Abdullah Karaer; Yavuz Simsek; Yagmur Minareci; Suleyman Aydin

Abstract Aim: To evaluate maternal and cord blood serum adropin concentrations in pregnant women with gestational diabetes mellitus (GDM). Study design: Twenty pregnant women with GDM and 20 gestational age-matched healthy pregnant women participated in the study. Maternal serum and cord blood adropin levels were assessed using an enzyme immunosorbent assay, at the time of birth. The relation of maternal serum and cord blood adropin levels with metabolic parameters were also assessed. Results: The mean maternal and cord serum adropin in the GDM group were significantly lower than those of the control women (P=0.01 and P<0.001, respectively). Maternal serum adropin levels did not correlate with either fetal serum adropin levels or maternal metabolic values. Conclusion: The data suggest that low adropin levels may contribute to the underlying pathogenesis of GDM.


Peptides | 2015

Peptides: Basic determinants of reproductive functions

Onder Celik; Suleyman Aydin; Nilufer Celik; Musa Yilmaz

Mammalian reproduction is a costly process in terms of energy consumption. The critical information regarding metabolic status is signaled to the hypothalamus mainly through peripheral peptides from the adipose tissue and gastrointestinal tract. Changes in energy stores produce fluctuations in leptin, insulin, ghrelin and glucose signals that feedback mainly to the hypothalamus to regulate metabolism and fertility. In near future, possible effects of the nutritional status on GnRH regulation can be evaluated by measuring serum or tissue levels of leptin and ghrelin in patiens suffering from infertility. The fact that leptin and ghrelin are antagonistic in their effects on GnRH neurons, their respective agonistic and antagonistic roles make them ideal candidates to use instead of GnRH agonist and antagonist. Similarly, kisspeptin expressing neurons are likely to mediate the well-established link between energy balance and reproductive functions. Exogenous kisspeptin can be used for physiological ovarian hyperstimulation for in-vitro fertilization. Moreover, kisspeptin antagonist therapy can be used for the treatment of postmenapousal women, precocious puberty, PCOS, endometriosis and uterine fibroids. In this review, we will analyze the central mechanisms involved in the integration of metabolic information and their contribution to the control of the reproductive function. Particular attention will be paid to summarize the participation of leptin, kisspeptin, ghrelin, NPY, orexin, urocortin, VIP, insulin, galanin, galanin like peptide, oxytocin, agouti gene-related peptide, and POMC neurons in this process and their possible interactions to contribute to the metabolic control of reproduction.


Gynecologic and Obstetric Investigation | 2005

Metabolic Changes in Pelvic Lesions: Findings at Proton MR Spectroscopic Imaging

Seyma Hascalik; Onder Celik; Kaya Saraç; M. Mutlu Meydanli; Alpay Alkan; Bulent Mizrak

Objective: The purpose of this study is to investigate the in vivo magnetic resonance spectroscopic (MRS) features of pelvic lesions using long echo time and to characterize the spectral patterns of various pathological entities. Materials and Methods: 17patients with surgically and histopathologically confirmed pelvic lesions underwent long echo-time MRS, and the results obtained were analyzed. Before laparotomy, choline (Cho), lactate, lipid and creatine (Cr) levels of all lesions were measured by single voxel MRS (point-resolved spectroscopy technique, TE 136 ms). Voxels were placed in the center of the lesions. The MRS results of lesions were compared with the final histopathological diagnoses. Results: Spectroscopy analysis of serous, mucinous and undifferentiated carcinoma of the ovary revealed Cho, lactate and lipid signals, but granulosa-theca cell tumor showed only a lipid signal. The Cho signal was obtained from only 3 patients with mature cystic teratoma but none of the other benign ovarian tumors and pelvic abscesses. A lipid signal was detected in 3 patients diagnosed with pelvic abscess and all benign ovarian tumors. In addition to the lipid signal, a lactate signal was detected in the spectra of two pelvic abscesses. One case of endometrioma and 1 case of teratoma did not show any signal. Conclusion: MRS demonstrates significant differences in metabolite concentration between benign and malignant ovarian tumors and pelvic abscesses. MRS may therefore be helpful in the differential diagnosis of adnexal lesions.


International Journal of Gynecology & Obstetrics | 2003

Reversible posterior leukoencephalopathy in eclampsia

Onder Celik; Seyma Hascalik

Posterior leukoencephalopathy syndrome (RPLS) is a newly recognized brain disorder that predominantly affects the cerebral white matter w1x. Its causes are diverse, but common precipitants are acute elevations of blood pressure, immunsuppressive drugs, hypertensive encephalopathy and eclampsia w1,2x. Sudden elevation in mean arterial pressure exceeds the autoregulatory capability of the brain vasculature and results in vasogenic edema w2x. T2-weighted images characteristically show symmetrical diffuse hyperintensity selectively involving the parieto-occipital lobe w1x. MR spectroscopy (MRS) is powerful and non-invasive chemical analysis tool and is widely used for brain lesions such as tumors, metabolic and neurodegenerative diseases w3x. Only isolated reports of MRS for RPLS accompanied by eclampsia have been published w4,5x. We calculated metabolite ratios in parieto-occipital lobes using single voxel MRS in a patient with RPLS initially and 4 months later. A 21-year-old, primigravid woman was seen at term with severe


Gynecologic and Obstetric Investigation | 2004

Magnetic Resonance Spectroscopy Features of Uterine Leiomyomas

Onder Celik; Kaya Saraç; Seyma Hascalik; Alpay Alkan; Bulent Mizrak; Saim Yologlu

Objective: The purpose of this study is to investigate the in vivo magnetic resonance spectroscopy features of uterine leiomyomas using long echo time and to characterize the spectral patterns of these lesions. Methods: We calculated metabolites in 15 patients with uterine leiomyomas and myometrium of 20 healthy control subjects using single-voxel proton MR spectroscopy (point resolved spectroscopy technique, TE:136 ms). Voxels were placed at the center of the uterine leiomyomas. The peak areas of creatine, choline, lipid and lactate were determined. The MR spectroscopy results of uterine leiomyomas were compared with the spectroscopy results obtained from the myometrium of healthy control subjects. Results: The characteristically obtained signal was choline, which was detected not only in 14 of the 15 leiomyomas (93.3%) but also in 18 of the 20 myometrium of control subjects (90%). The lipid signals were determined in 9 of 15 patients with uterine leiomyomas (60%) and 8 of 20 control subjects (40%). The lactate signal was obtained from six of 15 patients with leiomyomas (40%) but only two of myometrium (10%). The creatine signal was obtained from 4 of 15 patients with leiomyomas (26.6%) and 5 of 20 myometrium (25%). Among the tested parameters only lactate peak was statistically significant (p < 0.05). Conclusion: Proton MR spectroscopic imaging may be helpful for the investigation of the underlying pathophysiology of uterine leiomyomas. The presence of lactate and lipid signals in the spectrum may be a useful indicator of metabolic pathway of uterine leiomyomas.


Fertility and Sterility | 2015

Laparoscopic endometrioma resection increases peri-implantation endometrial HOXA-10 and HOXA-11 mRNA expression

Onder Celik; Cihat Unlu; Baris Otlu; Nilufer Celik; Eray Caliskan

OBJECTIVE To determine whether laparoscopic endometrioma resection alters peri-implantation endometrial HOXA-10, HOXA-11, LIF, ITGB3 and ITGAV mRNA expression. DESIGN Case-control study. SETTING Medical school. PATIENT(S) Twenty infertile patients with uni- or bilateral endometrioma, five infertile patients having nonendometriotic benign ovarian cyst, and five fertile control subjects. INTERVENTION(S) Mid-luteal-phase endometrial sampling was performed at the time of surgery. Second endometrial biopsies were obtained 3 months after laparoscopic endometrioma resection during the mid-luteal phase of the cycle. MAIN OUTCOME MEASURE(S) Endometrial HOXA-10, HOXA-11, LIF, ITGAV, and ITGB3 mRNA expressions were evaluated with the use of reverse-transcription polymerase chain reaction. RESULT(S) Significantly decreased endometrial ITGAV mRNA expression was noted in biopsies obtained from endometrioma and nonendometriotic cyst groups before surgery. Trends toward decreased endometrial HOXA-10, HOXA-11, LIF, and ITGB3 mRNA expressions were noted in the endometrioma and nonendometriotic cyst groups before surgery compared with the fertile subjects. However, the differences failed to show statistical significance. Compared with preoperative values, significantly increased HOXA-10 (12.1-fold change) and HOXA-11 (17.2-fold change) mRNA expressions were noted in endometrial biopsies obtained from subjects who were undergoing endometrioma surgery. Fold change in endometrial ITGAV mRNA after endometrioma surgery was found to be 30.1 and indicated a positive regulation. However, this fold increase was statistically insignificant. Expressions of these endometrial receptivity markers did not change significantly after surgical removal of nonendometriotic benign ovarian cysts. CONCLUSION(S) Laparoscopic endometrioma resection increases peri-implantation endometrial HOXA-10 and HOXA-11 mRNA expression, suggesting an improvement in endometrial receptivity.

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