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Dive into the research topics where Andreas N. Schüring is active.

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Featured researches published by Andreas N. Schüring.


Human Reproduction | 2008

Relevance of anti-Mullerian hormone measurement in a routine IVF program

Christian Gnoth; Andreas N. Schüring; Kerstin Friol; Jürgen Tigges; Peter Mallmann; Erhard Godehardt

BACKGROUND Diminished ovarian reserve has become a major cause of infertility. Anti-Mullerian hormone (AMH) seems to be a promising candidate to assess ovarian reserve and predict the response to controlled ovarian hyperstimulation (COH). This prospective study was conducted to evaluate the relevance of AMH in a routine IVF program. METHODS Three hundred and sixteen patients were prospectively enrolled to enter their first IVF/ICSI-cycle. Age, FSH-, inhibin B- and AMH-levels and their predictive values for ovarian response and clinical pregnancy rate were compared by discriminant analyses. RESULTS A total of 132 oocyte retrievals were performed. A calculated cut-off level < or =1.26 ng/ml AMH alone detected poor responders (< or =4 oocytes) with a sensitivity of 97%, and there was a 98% correct prediction of normal response in COH if levels were above this threshold. With levels <0.5 ng/ml, a correct prediction of very poor response (< or =2 oocytes) was possible in 88% of cases. Levels of AMH > or =0.5 ng/ml were not significantly correlated with clinical pregnancy rates. CONCLUSIONS AMH is a predictor of ovarian response and suitable for screening. Levels < or =1.26 ng/ml are highly predictive of reduced ovarian reserve and should be confirmed by a second line antral follicle count. Measurement of AMH supports clinical decisions, but alone it is not a suitable predictor of IVF success.


The Journal of Pathology | 2008

Increased expression of the adult stem cell marker Musashi‐1 in endometriosis and endometrial carcinoma

Martin Götte; M Wolf; A Staebler; Olaf Buchweitz; Reinhard Kelsch; Andreas N. Schüring; Ludwig Kiesel

Adult stem cells are thought to be responsible for the high regenerative capacity of the human endometrium, and have been implicated in the pathology of endometriosis and endometrial carcinoma. The RNA‐binding protein Musashi‐1 is associated with maintenance and asymmetric cell division of neural and epithelial progenitor cells. We investigated expression and localization of Musashi‐1 in endometrial, endometriotic and endometrial carcinoma tissue specimens of 46 patients. qPCR revealed significantly increased Musashi‐1 mRNA expression in the endometrium compared to the myometrium. Musashi‐1 protein expression presented as nuclear or cytoplasmic immunohistochemical staining of single cells in endometrial glands, and of single cells and cell groups in the endometrial stroma. Immunofluorescence microscopy revealed colocalization of Musashi‐1 with its molecular target Notch‐1 and telomerase. In proliferative endometrium, the proportion of Musashi‐1‐positive cells in the basalis layer was significantly increased 1.5‐fold in the stroma, and three‐fold in endometrial glands compared to the functionalis. The number of Musashi‐1 expressing cell groups was significantly increased (four‐fold) in proliferative compared to secretory endometrium. Musashi‐1 expressing stromal cell and cell group numbers were significantly increased (five‐fold) in both endometriotic and endometrial carcinoma tissue compared to secretory endometrium. A weak to moderate, diffuse cytoplasmic glandular staining was observed in 50% of the endometriosis cases and in 75% of the endometrioid carcinomas compared to complete absence in normal endometrial samples. Our results emphasize the role of Musashi‐1‐expressing endometrial progenitor cells in proliferating endometrium, endometriosis and endometrioid uterine carcinoma, and support the concept of a stem cell origin of endometriosis and endometrial carcinoma. Copyright


Fertility and Sterility | 2011

Characterization of endometrial mesenchymal stem-like cells obtained by endometrial biopsy during routine diagnostics

Andreas N. Schüring; Nicole Schulte; Reinhard Kelsch; Albrecht Röpke; Ludwig Kiesel; Martin Götte

Endometrial cell clones derived from in vitro cultured purified stromal cells obtained by endometrial biopsy display characteristic stem cell features, including clonality; long-term culturing properties; multilineage differentiation potential; expression of CD146, CD105, CD90, CD73, MSI1, NOTCH1, and SOX2; and absence of CD34 and CD14 expression. We conclude that adult stem cells are present in endometrial biopsies performed in a routine clinical setting, offering new large-scale approaches for future research, diagnostics, and therapies involving adult stem cells.


Reproductive Biomedicine Online | 2011

Effects of the FSH receptor gene polymorphism p.N680S on cAMP and steroid production in cultured primary human granulosa cells

Verena Nordhoff; Barbara Sonntag; Dominik von Tils; Martin Götte; Andreas N. Schüring; Jörg Gromoll; Klaus Redmann; Livio Casarini; Manuela Simoni

The study was designed to evaluate in vitro the cellular mechanisms of the single nucleotide polymorphism (SNP) p.N680S of the FSH receptor gene (FSHR) in human granulosa cells (GC) and included patients homozygous for the FSHR SNP (NN/SS) undergoing ovarian stimulation. GC were isolated during oocyte retrieval and cultured for 1–7 days. Basal oestradiol and progesterone concentrations were measured after short-term culture. The kinetics of cAMP, oestradiol and progesterone concentrations in response to various amounts of FSH were analysed in a 6–7 day culture. Basal oestradiol, but not progesterone, concentrations on day 1 of GC culture, were significantly higher in NN compared with SS (P = 0.045), but non-responsive to FSH stimulation. Immunofluorescence microscopy demonstrated the re-appearance of FSHR expression with increasing days in culture. Upon stimulation with FSH, GC cultured for 6–7 days displayed a dose-dependent increase of cAMP, oestradiol and progesterone but no difference in the EC50 values between both variants. Primary long-term GC cultures are a suitable system to study the effects of FSH in vitro. However, the experiments suggest that factors down-stream of progesterone production or external to GC might be involved in the clinically observed differences in an FSHR variant-mediated response to FSH.


Gynakologisch-geburtshilfliche Rundschau | 2008

Androgens and Insulin – Two Key Players in Polycystic Ovary Syndrome

Andreas N. Schüring; Nicole Schulte; Barbara Sonntag; Ludwig Kiesel

Androgens and insulin are endocrine key players in the pathophysiology of polycystic ovary syndrome (PCOS), a heterogenic condition of unexplained etiology and a suspected genetic background. Androgens mediate the clinical phenotype of the disease. Therefore,all criteria of the recent PCOS consensus definition are based on their biological effects. Insulin resistance, followed by compensatory hyperinsulinemia, is frequently found in patients with PCOS. Insulin resistance is correlated with a risk of metabolic complications of PCOS, and recent research has focused on possible long-term health consequences of the syndrome. Newest molecular genetic findings at the receptor level of both androgens and insulin support their pivotal role in PCOS. These results could help to better characterize the heterogenic disorder, enabling a refinement of existing individualized therapeutic strategies.


Fertility and Sterility | 2011

Aberrant expression of the pluripotency marker SOX-2 in endometriosis

Martin Götte; Maria Wolf; Annette Staebler; Olaf Buchweitz; Ludwig Kiesel; Andreas N. Schüring

Expression of the pluripotency factors SOX-2, OCT-4, KLF-4, and NANOG was analyzed by quantitative real-time polymerase chain reaction, immunohistochemistry, and immunofluorescence microscopy in the endometrium, myometrium, and endometriotic tissue of 36 patients. Aberrant expression of SOX-2 may indicate a stem cell origin of endometriosis, whereas the presence of all progenitor markers in endometrial tissue marks the endometrium as a potential source for induced pluripotent stem cell generation.


Reproductive Biomedicine Online | 2015

Fertility-preservation counselling and treatment for medical reasons: data from a multinational network of over 5000 women

Michael von Wolff; Ralf Dittrich; Jana Liebenthron; Frank Nawroth; Andreas N. Schüring; Thomas Bruckner; Ariane Germeyer

Fertility-preservation techniques for medical reasons are increasingly offered in national networks. Knowledge of the characteristics of counselled patients and techniques used are essential. The FertiPROTEKT network registry was analysed between 2007 and 2013, and included up to 85 university and non-university centres in Germany, Austria and Switzerland; 5159 women were counselled and 4060 women underwent fertility preservation. In 2013, fertility-preservation counselling for medical reasons increased significantly among nullipara and women aged between 21 and 35 years (n = 1043; P < 0.001). Frequency of GnRH applications slowly decreased, whereas tissue, oocytes and zygote cryopreservation increased. In 2013, women with breast cancer mainly opted for tissue freezing, whereas women with lymphoma opted for GnRH agonist. Women younger than 20 years predominantly opted for GnRH agonists and ovarian tissue cryopreservation; women aged between 20 and 40 years underwent a variety of techniques; and women over 40 years opted for GnRH agonists. The average number of aspirated oocytes per stimulation cycle decreased as age increased (< 30 years: 12.9; 31-35 years: 12.3; 36-46: 9.0; > 41 years: 5.7). For ovarian tissue cryopreservation, removal and cryopreservation of fewer than one ovary was preferred and carried out in 97% of cases in 2013.


Reproductive Biomedicine Online | 2016

microRNA miR-200b affects proliferation, invasiveness and stemness of endometriotic cells by targeting ZEB1, ZEB2 and KLF4

Julia C. Eggers; Valentina Martino; Rolland Reinbold; S. Schäfer; Ludwig Kiesel; Anna Starzinski-Powitz; Andreas N. Schüring; Björn Kemper; Burkhard Greve; Martin Götte

Endometriosis is characterized by growth of endometrial tissue at ectopic locations. Down-regulation of microRNA miR-200b is observed in endometriosis and malignant disease, driving tumour cells towards an invasive state by enhancing epithelial-to-mesenchymal transition (EMT). miR-200b up-regulation may inhibit EMT and invasive growth in endometriosis. To study its functional impact on the immortalized endometriotic cell line 12Z, the stromal cell line ST-T1b, and primary endometriotic stroma cells, a transient transfection approach with microRNA precursors was employed. Expression of bioinformatically predicted targets of miR-200b was analysed by qPCR. The cellular phenotype was monitored by Matrigel invasion assays, digital-holographic video microscopy and flow cytometry. qPCR revealed significant down-regulation of ZEB1 (P < 0.05) and ZEB2 (P < 0.01) and an increase in E-cadherin (P < 0.01). miR-200b overexpression decreased invasiveness (P < 0.0001) and cell motility (P < 0.05). In contrast, cell proliferation (P < 0.0001) and the stemness-associated side population phenotype (P < 0.01) were enhanced following miR-200b transfection. These properties were possibly due to up-regulation of the pluripotency-associated transcription factor KLF4 (P < 0.05) and require attention when considering therapeutic strategies. In conclusion, up-regulation of miR-200b reverts EMT, emerging as a potential therapeutic approach to inhibit endometriotic cell motility and invasiveness.


Fertility and Sterility | 2015

Xenotransplantation of cryopreserved human ovarian tissue--a systematic review of MII oocyte maturation and discussion of it as a realistic option for restoring fertility after cancer treatment.

Ralf Dittrich; Laura Lotz; Tanja Fehm; Jan S. Krüssel; Michael von Wolff; Bettina Toth; Hans van der Ven; Andreas N. Schüring; Wolfgang Würfel; Inge Hoffmann; Matthias W. Beckmann

OBJECTIVE To systematically review the reporting of MII (MII) oocyte development after xenotransplantation of human ovarian tissue. DESIGN Systematic review in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). SETTING Not applicable. PATIENT(S) Not applicable. INTERVENTION(S) Formation of MII oocytes after xenotransplantation of human ovarian tissue. MAIN OUTCOME MEASURE(S) Any outcome reported in Pubmed. RESULT(S) Six publications were identified that report on formation of MII oocytes after xenotransplantation of human ovarian tissue. CONCLUSION(S) Xenografting of human ovarian tissue has proved to be a useful model for examining ovarian function and follicle development in vivo. With human follicles that have matured through xenografting, the possibility of cancer transmission and relapse can also be eliminated, because cancer cells are not able to penetrate the zona pellucida. The reported studies have demonstrated that xenografted ovarian tissue from a range of species, including humans, can produce antral follicles that contain mature (MII) oocytes, and it has been shown that mice oocytes have the potential to give rise to live young. Although some ethical questions remain unresolved, xenotransplantation may be a promising method for restoring fertility. This review furthermore describes the value of xenotransplantation as a tool in reproductive biology and discusses the ethical and potential safety issues regarding ovarian tissue xenotransplantation as a means of recovering fertility.


The Journal of Clinical Endocrinology and Metabolism | 2013

Effects of the FSH-β-Subunit Promoter Polymorphism −211G→T on the Hypothalamic-Pituitary-Ovarian Axis in Normally Cycling Women Indicate a Gender-Specific Regulation of Gonadotropin Secretion

Andreas N. Schüring; Alexander S. Busch; Nadja Bogdanova; Jörg Gromoll; Frank Tüttelmann

CONTEXT A polymorphism in the FSHB promoter (-211G→T, rs10835638) was found to be associated with decreased FSH, elevated LH, reduced testosterone, and oligozoospermia in males. Although FSH is pivotal for ovarian function, no data on consequences of FSHB -211G→T are available in females. OBJECTIVE We studied the effects of FSHB -211G→T on the hypothalamic-pituitary-ovarian axis in women. DESIGN AND SETTING In a university-based in vitro fertilization unit, women undergoing standardized diagnostics were genotyped and compared with a fertile control group. PATIENTS The study group consisted of 365 thoroughly characterized women with normal menstrual cycle intervals and proven ovulation, with predominantly male-factor infertility. The independently recruited control group included 438 women with proven fertility and no history of abortions. MAIN OUTCOME MEASURES Distribution of alleles and genotypes were compared between the study group and controls. In the study group, associations of endocrine parameters with FSHB -211G→T were assessed. RESULTS Allele and genotype frequencies were not significantly different between the study population and controls (T-allele: 14.4 vs. 16.6%; TT-homozygotes: 2.5 vs. 3.2%). The FSHB -211G→T TT-genotype was strongly associated with elevated FSH (TT-homozygosity effect 2.05 U/liter, P = 0.003). LH increased with the number of T-alleles (1.30 U/liter per T-allele, P < 0.001). Additionally, FSHB -211G→T was associated with reduced progesterone (-1.96 ng/ml per T-allele, P = 0.047). CONCLUSIONS This is a report on phenotypic consequences of FSHB -211G→T on the hypothalamic-pituitary-ovarian axis in women. The findings, partially contradictory to those in men, point to a gender-specific compensatory mechanism of gonadotropin secretion, probably involving progesterone.

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Ralf Dittrich

University of Erlangen-Nuremberg

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