Araştırma Çıktıları

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Author: search.filters.author.Celik, Onder

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Now showing 1 - 7 of 7
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    Navigation problems of ICSI or naive blastocyst can be solved with artificial blastocyst
    (BIOMED CENTRAL LTD, 2018-01-01) Celik, Onder; Acet, Mustafa; Arpaci, Haldun; Dikbas, Levent; Imren, Aytac; Duran, Bulent; Celik, Nilufer; Celik, Sudenaz; Unlu, Cihat; Sahin, Ibrahim; Aydin, Suleyman
    Embryos have evolved a remarkable capacity to find implantation site. The impressive navigation ability of natural blastocysts may rely on highly sensitive signals arising from embryos and specialized signal processing strategies in the endometrium. Navigation capabilities may be compromised in ICSI embryos because of altered biochemical signaling. The design and delivery of artificial blastocyst (AB) carrying strong chemical signals may allow ICSI embryos to more easily locate to and be retained in the implantation zone. ICSI embryos will attach easily to the implantation zone after it is found by the AB. Co-transfer of the AB together with the ICSI embryo may overcome potential difficulties in implantation due to impaired embryo-maternal communication in cases with implantation failure.
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    Receptivity-based uterine fibroid surgery: an updated systematic review of the evidence
    (IMR PRESS, 2022-01-01) Celik, Onder; Koc, Onder; Yurci, Arzu; Ersahin, Aynur; Celik, Nilufer; Tanilir, Fatma; Gurkan, Naziye; Ozyurt, Ramazan; Ozcil, Mustafa Dogan; Duran, Bulent; Unlu, Cihat
    Background: Analyzing expression patterns of receptivity genes is a minimally invasive diagnostic method to identify the underlying cause of subfertility in women with uterine fibroid with a history of implantation failure or recurrent pregnancy loss. This updated systematic review was designed to determine the molecular and genetic changes in the endometrium of women with fibroid and how myomctomy affect the outcome of spontaneous or assisted conception treatment. We also discussed the extent to which we should consider the effects of fibroids on endometrial receptivity when deciding whether or not to perform myomectomy. Methods: A total of 184 articles reached as a result of PubMed research and meeting the selection criteria, were evaluated. Of these, 28 full text articles on uterine leiomyoma and endometrium, leiomyoma and receptivity, fibroid and implantation, myomectomy and implantation, fibroid and genes, fibroid surgery and receptivity, fibroid and uterine peristalsis, fibroid and immune cell were evaluated. Results: The endometrium of subfertile women with fibroid appears to have a disease specific pattern according to the type of the fibroid. The response of the endometrium to a fibroid may vary depending on whether the fibroid is close or far from it. Leiomyomas that contribute to subfertility must be near to or in contact with the endometrium, as is the case for Types 0, 1 and 2 leiomyomas. The proximity to the endometrial cavity makes the effect of fibroid on the endometrium more pronounced. While Type 3 fibroid causes subfertility similar to submucosal fibroids, the subfertility-producing effects of Type 4 fibroids have not been clearly clarified. However, the fact that the fibroid is far from the cavity should not mean that it has no effect on the endometrium. The mechanical stress created by a Type 4 fibroid that is not connected to the endometrium may be converted into biological signal and disrupt receptivity. Data on whether myomectomy restores impaired receptivity are mostly based on clinical observations, and studies evaluating endometrial receptivity before and after myomectomy are very few. Conclusions: Analysis of receptivity genes in subfertile women with fibroid may assist the clinician in deciding whether or not to perform myomectomy. If it is determined whether fibroids affect receptivity other than their mechanical effects, the indications for myomectomy may expand or narrow.
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    DHEA supplementation improves endometrial HOXA-10 mRNA expression in poor responders
    (GALENOS YAYINCILIK, 2017-01-01) Celik, Onder; Acet, Mustafa; Imren, Aytac; Celik, Nilufer; Ersahin, Aynur; Aktun, Lebriz Hale; Otlu, Baris; Celik, Sudenaz; Caliskan, Eray; Unlu, Cihat
    Objective: The study was planned to investigate whether DHEA supplementation had an impact on endometrial receptivity in women who were poor responders (POR). Material and Methods: Twenty-eight POR women who were undergoing hysteroscopy and five fertile control subjects were included. The POR women were equally subdivided into two separate groups as patients who were currently using DHEA and those who were not. Endometrial samples of the subjects were obtained during hysteroscopy at the late follicular phase. Expression levels of endometrial HOXA-10, HOXA-11, and LIF mRNA were measured with the using real-time polymerase chain reaction. Spontaneous clinical pregnancy rates were also noted. Results: Compared with POR women who were not given DHEA, upregulated endometrial HOXA-10 (7.33-fold) and HOXA-11 (2.39-fold) mRNA expression were detected in POR women on DHEA. The increase in HOXA-10 mRNA was significant (p<0.03). The fold increase in HOXA-11 mRNA was found as 2.39, which indicated a positive upregulation. However, this fold increment was insignificant (p<0.45). An insignificant increase in spontaneous clinical pregnancy rates in POR women on DHEA (53.3\%) was observed compared with POR women who were not given DHEA (43.8\%). Conclusion: Oral DHEA supplementation in POR upregulates endometrial HOXA-10 mRNA expression, which is known to positively modulate endometrial receptivity.
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    Testis spectroscopy may predict sperm retrieval rate in men with non-obstructive azoospermia undergoing micro-TESE: A pilot study
    (GALENOS YAYINCILIK, 2020-01-01) Celik, Onder; Hatirnaz, Safak; Ersahin, Aynur; Basbug, Alper; Yildirim, Gonca Yetkin; Ozener, Vahit; Gurpinar, Neslihan; Celik, Sudenaz; Celik, Nilufer; Kucuk, Tansu; Unlu, Cihat
    Objective: To investigate whether prior testis magnetic resonance spectroscopy predicts the success or failure of micro-dissection testicular sperm extraction (micro-TESE) in patients with non-obstructive azoospermia (NOA). Material and Methods: Nine men with NOA who were scheduled for micro-TESE for the first time, 9 NOA men with a history of previous micro-TESE and 5 fertile men were enrolled. All NOA patients and fertile controls underwent testis spectroscopy. A multi-voxel spectroscopy sequence was used. Testicular signals of choline (Cho), creatine (Cr), myo-inositol (MI), lactate, and lipids were analyzed quantitatively and compared with the results of the micro-TESEs. Results: The most prominent peaks were Cho and Cr in the fertile controls and NOA subjects with positive sperm retrieval in the micro-TESE. A high Cho peak was detected in 87\% of the NOA men with positive sperm retrieval. NOA men without sperm at the previous micro-TESE showed a marked decrease in Cho and Cr signals. For positive sperm retrieval in micro-TESE, the cut-off value of Cho was 1.46 ppm, the cut-off value of Cr was 1.43 ppm, and the cut-off value of MI was 0.79 ppm. Conclusion: Testis spectroscopy can be used as a non-invasive screening method to predict the success or failure of micro-TESE.
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    Fertility preservation in Turkey: a global look for nationwide strategy development
    (GALENOS YAYINCILIK, 2019-01-01) Hatirnaz, Safak; Bakay, Kadir; Hatirnaz, Ebru; Guven, Davut; Basbug, Alper; Celik, Onder; Yildirim, Gazi; Unlu, Cihat
    As the reproductive technology advanced along with the improved outcome in cancer treatment demands implementing new fertility preservation, developing algorithms on fertility preservation requires tailoring for each society. Here, the authors attempt to modify the current medical literature on fertility preservation for the Turkish population. A PubMed search was conducted using the search term fertility preservation. Initially, 280 items of literature were accessed. In the second evaluation, 126 articles were examined and 154 items were discarded due to the low quality of the literature. In the final round, only 68 publications that were the most relevant were found eligible for inclusion in this review article. In order to develop a more systematic national guideline, forming a multidisciplinary approach to create a web-based network would be the first step. Both physicians and patients will have open access to the information. This database should be linked to an international consortium to stay integrated and open for updating. The aim of this review was to evaluate the relationship between the current situation in our country and the developments in the world in light of the literature, and to establish infrastructure for the development of future approaches in our country.
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    Laparoscopic endometrioma resection increases peri-implantation endometrial HOXA-10 and HOXA-11 mRNA expression
    (ELSEVIER SCIENCE INC, 2015-01-01) Celik, Onder; Unlu, Cihat; Otlu, Baris; Celik, Nilufer; Caliskan, Eray
    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. (C) 2015 by American Society for Reproductive Medicine.
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    Germline cells in ovarian surface epithelium of mammalians: a promising notion
    (BMC, 2012-01-01) Celik, Onder; Celik, Ebru; Turkcuoglu, Ilgin; Yilmaz, Ercan; Simsek, Yavuz; Tiras, Bulent
    It is a long held doctrine in reproductive biology that women are born with a finite number of oocytes and there is no oogenesis during the postnatal period. However, recent evidence challenges this by showing the presence of germ line stem cells in the human ovarian surface epithelium (OSE), which can serve as a source of germ cells, and differentiate into oocyte like structures. Postnatal renewal of oocytes may have enormous therapeutic potential especially in women facing the risk of premature ovarian failure idiopathically or iatrogenically after exposure to gonadotoxic chemotherapy and radiation for cancer therapy. This article reviews current knowledge on germ line stem cells in human OSE.