Gülen Yerlikaya-Schatten

Gülen Yerlikaya-Schatten

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 August 2016 in Ultrasound in Obstetrics & Gynecology
Verified
Journal Article
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LPLiona C. Poon
Liona C. Poon
MTM. Y. Tan
M. Y. Tan
GYGülen Yerlikaya-Schatten
Gülen Yerlikaya-Schatten
ASArgyro Syngelaki
Argyro Syngelaki
KNKypros Herodotos Nicolaides
Kypros Herodotos Nicolaides
Objective: To establish a normal range of birth weights for gestational age at delivery and to compare the proportion of live births and stillbirths that are classified as small‐for‐gestational age (SGA) according to our normal range vs that of the INTERGROWTH‐21st standard.Methods: The study population comprised 113 019 live births and 437 (0.4%) stillbirths. The inclusion criterion for establishing a normal range of birth weights for gestational age was the live birth of a phenotypically normal neonate ≥ 24 weeks' gestation and the exclusion criteria were smoking and prepregnancy hypertension, diabetes mellitus, systemic lupus erythematosus or antiphospholipid syndrome, pre‐eclampsia, gestational hypertension, gestational diabetes mellitus or iatrogenic preterm birth for fetal growth restriction in the current pregnancy. Inclusion criteria were met by 92 018 live births. The proportions of live births and stillbirths with birth weights < 5th and < 10th percentiles of our normal range and those according to the INTERGROWTH‐21st standard were determined and compared by the chi‐square test and McNemar test.Results: The proportions of live births and stillbirths with a birth weight < 5th percentile according to our standard were significantly higher than and discordant with the proportion according to the INTERGROWTH‐21st standard (live birth: 5.6% vs 3.4%; stillbirth: 37.2% vs 22.7%). Similarly, the proportion of live births and stillbirths with a birth weight < 10th percentile according to our standard were significantly higher than and discordant with those according to the INTERGROWTH‐21st standard (live birth: 11.2% vs 6.9%; stillbirth: 44.3% vs 32.6%).Conclusion: The INTERGROWTH‐21st standard underestimates the proportion of SGA live births and stillbirths in our population. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

22 July 2015 in Reproductive Biology and Endocrinology
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Journal Article
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KPKatharina Proestling
Katharina Proestling
PBPeter Birner
Peter Birner
SGSusanne Gamperl
Susanne Gamperl
NNNadine Nirtl
Nadine Nirtl
EMErika Marton
Erika Marton
HHHeinrich Husslein
Heinrich Husslein
Epithelial to mesenchymal transition (EMT) is a process in which epithelial cells lose polarity and cell-to-cell contacts and acquire the migratory and invasive abilities of mesenchymal cells. These abilities are thought to be prerequisites for the establishment of endometriotic lesions. A hallmark of EMT is the functional loss of E-cadherin (CDH1) expression in epithelial cells. TWIST1, a transcription factor that represses E-cadherin transcription, is among the EMT inducers. SNAIL, a zinc-finger transcription factor, and its close relative SLUG have similar properties to TWIST1 and are thus also EMT inducers. MYC, which is upregulated by estrogens in the uterus by an estrogen response cis-acting element (ERE) in its promoter, is associated with proliferation in endometriosis. The role of EMT and proliferation in the pathogenesis of endometriosis was evaluated by analyzing TWIST1, CDH1 and MYC expression. CDH1, TWIST1, SNAIL and SLUG mRNA expression was analyzed by qRT-PCR from 47 controls and 74 patients with endometriosis. Approximately 42 ectopic and 62 eutopic endometrial tissues, of which 30 were matched samples, were collected during the same surgical procedure. We evaluated TWIST1 and MYC protein expression by immunohistochemistry (IHC) in the epithelial and stromal tissue of 69 eutopic and 90 ectopic endometrium samples, of which 49 matched samples were analyzed from the same patient. Concordant expression of TWIST1/SNAIL/SLUG and CDH1 but also of TWIST1 and MYC was analyzed. We found that TWIST1, SNAIL and SLUG are overexpressed (p < 0.001, p = 0.016 and p < 0.001) in endometriosis, while CDH1 expression was concordantly reduced in these samples (p < 0.001). Similar to TWIST1, the epithelial expression of MYC was also significantly enhanced in ectopic endometrium compared to eutopic tissues (p = 0.008). We found exclusive expression of either TWIST1 or MYC in the same samples (p = 0.003). Epithelial TWIST1 is overexpressed in endometriosis and may contribute to the formation of endometriotic lesions by inducing epithelial to mesenchymal transition, as CDH1 was reduced in ectopic lesions. We found exclusive expression of either TWIST1 or MYC in the same samples, indicating that EMT and proliferation contribute independently of each other to the formation of endometriotic lesions.

1 January 2013 in Reproductive Biology and Endocrinology
Verified
Journal Article
Open access
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AKAngela Köninger
Angela Köninger
AKAlexis Kauth
Alexis Kauth
BSBörge Schmidt
Börge Schmidt
MSMarkus Schmidt
Markus Schmidt
GYGülen Yerlikaya-Schatten
Gülen Yerlikaya-Schatten
CBCahit Birdir
Cahit Birdir
The number of unintentionally childless couples is increasing as more couples seek to conceive for the first time in the third or fourth decade of the woman’s life. Determination of ovarian reserve is an essential component of infertility assessment. The Anti-Müllerian-Hormone (AMH) seems to be the most reliable predictor of ovarian reserve. In this study we analyzed AMH in a cohort of pregnant women without fertility impairment to determine age-dependent decline and possible AMH fluctuations during pregnancy and postpartum. A total of 554 healthy women aged 16 to 47 years without history of infertility or previous surgery on the ovaries were enrolled in the study between 1995 and 2012. In 450 women, a single measurement of AMH was taken during pregnancy, allowing for cross sectional analysis of trimester- and age-related differences in AMH levels. For another 15 women longitudinal data on AMH levels for all trimesters was recorded. In addition, for 69 women AMH was measured at the time just before and after delivery, and for another 20 AMH was measured just before delivery and once on each of the first four days after delivery. We used AMH-Gen-II ELISA (Beckman Coulter, Immunotech, Webster, USA) for the assessment of AMH levels. Non-parametric statistical tests were used to compare AMH levels between age groups, trimesters and postpartum. Comparison between the trimesters revealed a significant difference in AMH values at each trimester (first trimester: 1.69 ng/ml (IQR 0.71–3.10), second trimester: 0.8 ng/ml (IQR 0.48–1.41), third trimester: 0.5 ng/ml (IQR 0.18–1.00)). AMH significantly dropped during the course of pregnancy and immediately after delivery, whereas an increase was observed over the first four days postpartum. Women, greater than or equal to 35 years, showed significant lower AMH levels than those <35 years across all trimesters. AMH levels decrease during pregnancy. The decline in AMH levels during pregnancy indicates ovarian suppression. AMH levels recover quickly after delivery. AMH levels assessed in pregnant women are not an accurate indicator of ovarian reserve, since AMH levels during pregnancy seem not to be independent of gestational age.

23 February 2017 in Human Reproduction
Verified
Journal Article
Closed access
LKL Kuessel
L Kuessel
RWR Wenzl
R Wenzl
KPKatharina Proestling
Katharina Proestling
SBS Balendran
S Balendran
PPP Pateisky
P Pateisky
HHHeinrich Husslein
Heinrich Husslein
Do cell adhesion molecules play a role in endometriosis, and can they be used as a biomarker for diagnosing endometriosis? Altered expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in the endometrium and peritoneum may play a key role in endometriosis and the soluble VCAM-1/soluble ICAM-1 ratio is a promising biomarker. Cell adhesion molecules are cell surface proteins that mediate cellular adherence, inflammatory and immune responses, and cancer-related biological processes. Altered expression of VCAM-1 and ICAM-1 in women with endometriosis has been investigated previously; however, gene expression levels in tissues and protein levels in the serum have not been investigated in the same patients. We performed a prospective, longitudinal study (the Endometriosis Marker Austria) in patients who underwent a laparoscopy for benign gynecological pathology in a university-based tertiary referral center for endometriosis. From a total of 138 women who were included in the study from July 2013 through September 2014, 97 had not received hormonal treatment for at least 3 months prior to recruitment and were included in the analysis; 49 (50.5%) of these women had endometriosis, and the 48 (49.5%) who did not have endometriosis served as a control group. During laparoscopy, tissue samples were obtained from ectopic and eutopic endometrium, and from normal pelvic peritoneum. In addition, serum samples were collected immediately before and 6-10 weeks after surgery. The mRNA levels of VCAM-1, ICAM-1 and epithelial cell adhesion molecule (EpCAM) were measured using quantitative real-time PCR, and serum protein levels of soluble VCAM-1 (sVCAM-1), ICAM-1 (sICAM-1) and EpCAM (sEpCAM) were measured using ELISA and correlated with endometriosis status. The mRNA levels of both VCAM-1 and ICAM-1 were higher in ectopic endometriotic lesions than in eutopic endometrium (P < 0.001). Moreover, the mRNA levels of both VCAM-1 and ICAM-1 were higher in normal peritoneum samples obtained from women with endometriosis compared to those from controls (P = 0.038 and P = 0.009). The mRNA levels of VCAM-1 were also higher in the eutopic endometrium samples obtained from women with endometriosis compared to controls (P = 0.018). With respect to serum protein levels, compared to controls, the women with endometriosis had lower serum levels of sICAM-1 (P = 0.042) and higher levels of sVCAM-1 (P < 0.001). Our analysis revealed that the serum levels of sVCAM-1 were not affected by lesion entity, menstrual cycle phase or disease severity. An receiver operating characteristics curve, calculated to determine whether preoperative serum sVCAM-1 concentration can be used to predict endometriosis, found an AUC of 0.868 with 80% specificity and 84% sensitivity at a cutoff value of 370 pg/ml. This predictive performance can be further improved by calculation of the sVCAM-1/sICAM-1 ratio, leading to an AUC of 0.929 with 86.7% specificity and 90.3% sensitivity at a cutoff ratio value of 1.55. Not applicable. The relatively small sample size in the expression analyses is a possible limitation of this study. Our findings could contribute to an improved understanding of the pathogenesis of endometriosis and the role of cell adhesion molecules. In addition, the results may lead to the development of new, non-invasive tools for diagnosing endometriosis. The ability to diagnose patients by measuring serum sVCAM-1 levels or the sVCAM-1/sICAM-1 ratio would have considerable clinical value. The Ingrid Flick Foundation (Grant no. FA751C0801), which played no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors declare no competing interests.

5 October 2016 in Ultrasound in Obstetrics & Gynecology
Verified
Journal Article
Closed access
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GYGülen Yerlikaya-Schatten
Gülen Yerlikaya-Schatten
RARanjit Akolekar
Ranjit Akolekar
KMK. McPherson
K. McPherson
ASArgyro Syngelaki
Argyro Syngelaki
KNKypros Herodotos Nicolaides
Kypros Herodotos Nicolaides

1 September 2016 in European Journal of Obstetrics & Gynecology and Reproductive Biology
Verified
Journal Article
Closed access
GYGülen Yerlikaya-Schatten
Gülen Yerlikaya-Schatten
SBSukirthini Balendran
Sukirthini Balendran
KPKatharina Proestling
Katharina Proestling
TRTheresa Reischer
Theresa Reischer
PBPeter Birner
Peter Birner
HHHeinrich Husslein
Heinrich Husslein