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Featured researches published by A. Meissner.


Fertility and Sterility | 2014

Enrichment of spermatogonial stem cells from long-term cultured human testicular cells

Bita Nickkholgh; Sefika C. Mizrak; Cindy M. Korver; Saskia K.M. van Daalen; A. Meissner; Sjoerd Repping; Ans M.M. van Pelt

OBJECTIVE To evaluate the degree of enrichment of spermatogonial stem cells (SSCs) from human testicular cell cultures by ITGA6+, HLA-/ITGA6+, GPR125+, and HLA-/GPR125+ magnetic-assisted cell sorting (MACS). DESIGN Experimental basic science study. SETTING Reproductive biology laboratory. PATIENT(S) Multiple samples of cryopreserved human testicular cells from two prostate cancer patients with normal spermatogenesis. INTERVENTION(S) Cultured human testicular cells subjected to four sorting strategies based on MACS and xenotransplanted to the testes of mice to determine the enrichment for SSCs. MAIN OUTCOME MEASURE(S) Enrichment for human spermatogonia and SSCs tested by expression analysis of spermatogonial markers ITGA6, GPR125, ZBTB16, UCHL1, and ID4 using quantitative real-time polymerase chain reaction (qPCR) and by xenotransplantation into the testes of mice, respectively. RESULT(S) Compared with the nonsorted cultured testicular cells, only the ITGA6+ and HLA-/GPR125+ sorted cells showed enrichment for ID4. No difference in expression of ZBTB16 and UCHL1 was observed. Xenotransplantation of the sorted cell fractions showed a 7.1-fold enrichment of SSCs with ITGA6+. CONCLUSION(S) Magnetic-assisted cell sorting of cultured human testicular cells using ITGA6 allows for enrichment of SSCs, which aids in further molecular characterization of cultured human SSCs and enhances testicular colonization upon transplantation in future clinical settings.


The Journal of Sexual Medicine | 2009

Oral phosphodiesterase type 5 inhibitors alleviate recurrent priapism complicating thalassemia intermedia: a case report.

Vassilios Tzortzis; Lampros Mitrakas; Stavros Gravas; Charalampos Mamoulakis; A. Meissner; Despina Kyriakou; Michael D. Melekos

INTRODUCTION Recurrent ischemic priapism still remains a serious and difficult to treat complication of certain hematological disorders. Elucidation of the underlying pathophysiologic mechanisms and application of new effective prophylactic treatments are needed. AIM To present the efficacy of phosphodiesterase type 5 inhibitors (PDE5is) as a preventive measure against ischemic priapism recurrences complicating thalassemia intermedia. METHODS We report on the case of a 19-year-old Caucasian man with thalassemia intermedia complicated by recurrent episodes of priapism following therapeutic splenectomy. After failure of conventional measures to control recurrences, a trial of long-term PDE5is use was initiated. MAIN OUTCOME MEASURES PDE5is efficacy based on clinical patient history. RESULTS Within 2 months of PDE5i preventive strategy, priapism recurrences nearly resolved. At 6 months, prophylaxis was discontinued. At 12 months, the patient reported clear improvement and satisfaction, experiencing rare episodes of priapism and a physiologic erectile function. CONCLUSIONS PDE5 dysregulation seems to be an underline pathogenetic mechanism of thalassemia intermedia-associated priapism. It appears that PDE5is might have a role in the clinical management of such patients and their preventive efficacy warrants further testing in clinical trials.


Human Reproduction | 2016

Prediction model for obtaining spermatozoa with testicular sperm extraction in men with non-obstructive azoospermia

M. Cissen; A.M. Meijerink; K.W.M. D'Hauwers; A. Meissner; N. van der Weide; M.H. Mochtar; A.A. de Melker; Liliana Ramos; Sjoerd Repping; Didi D.M. Braat; Kathrin Fleischer; M. van Wely

STUDY QUESTION Can an externally validated model, based on biological variables, be developed to predict successful sperm retrieval with testicular sperm extraction (TESE) in men with non-obstructive azoospermia (NOA) using a large nationwide cohort? SUMMARY ANSWER Our prediction model including six variables was able to make a good distinction between men with a good chance and men with a poor chance of obtaining spermatozoa with TESE. WHAT IS KNOWN ALREADY Using ICSI in combination with TESE even men suffering from NOA are able to father their own biological child. Only in approximately half of the patients with NOA can testicular sperm be retrieved successfully. The few models that have been developed to predict the chance of obtaining spermatozoa with TESE were based on small datasets and none of them have been validated externally. STUDY DESIGN, SIZE, DURATION We performed a retrospective nationwide cohort study. Data from 1371 TESE procedures were collected between June 2007 and June 2015 in the two fertility centres. PARTICIPANTS/MATERIALS, SETTING, METHODS All men with NOA undergoing their first TESE procedure as part of a fertility treatment were included. The primary end-point was the presence of one or more spermatozoa (regardless of their motility) in the testicular biopsies.We constructed a model for the prediction of successful sperm retrieval, using univariable and multivariable binary logistic regression analysis and the dataset from one centre. This model was then validated using the dataset from the other centre. The area under the receiver-operating characteristic curve (AUC) was calculated and model calibration was assessed. MAIN RESULTS AND THE ROLE OF CHANCE There were 599 (43.7%) successful sperm retrievals after a first TESE procedure. The prediction model, built after multivariable logistic regression analysis, demonstrated that higher male age, higher levels of serum testosterone and lower levels of FSH and LH were predictive for successful sperm retrieval. Diagnosis of idiopathic NOA and the presence of an azoospermia factor c gene deletion were predictive for unsuccessful sperm retrieval. The AUC was 0.69 (95% confidence interval (CI): 0.66-0.72). The difference between the mean observed chance and the mean predicted chance was <2.0% in all groups, indicating good calibration. In validation, the model had moderate discriminative capacity (AUC 0.65, 95% CI: 0.62-0.72) and moderate calibration: the predicted probability never differed by more than 9.2% of the mean observed probability. LIMITATIONS, REASONS FOR CAUTION The percentage of men with Klinefelter syndrome among men diagnosed with NOA is expected to be higher than in our study population, which is a potential selection bias. The ability of the sperm retrieved to fertilize an oocyte and produce a live birth was not tested. WIDER IMPLICATIONS OF THE FINDINGS This model can help in clinical decision-making in men with NOA by reliably predicting the chance of obtaining spermatozoa with TESE. STUDY FUNDING/COMPETING INTEREST This study was partly supported by an unconditional grant from Merck Serono (to D.D.M.B. and K.F.) and by the Department of Obstetrics and Gynaecology of Radboud University Medical Center, Nijmegen, The Netherlands, the Department of Obstetrics and Gynaecology, Jeroen Bosch Hospital, Den Bosch, The Netherlands, and the Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, The Netherlands. Merck Serono had no influence in concept, design nor elaboration of this study. TRIAL REGISTRATION NUMBER Not applicable.


Human Reproduction | 2015

Live birth rates after MESA or TESE in men with obstructive azoospermia: is there a difference?

Madelon van Wely; Natalie Barbey; A. Meissner; Sjoerd Repping; Sherman J. Silber

STUDY QUESTION How do live birth rates compare after intracytoplasmic sperm injection (ICSI) for men with obstructive azoospermia when using sperm derived from testicular sperm extraction (TESE) versus microsurgical epididymal sperm aspiration (MESA)? SUMMARY ANSWER Our study suggests that proximal epididymal sperm (from MESA) result in higher live birth rates as compared with testicular sperm (from TESE) in couples where the man has obstructive azoospermia due to congenital bilateral absence of the vas deferens (CBAVD) or vasectomy. WHAT IS KNOWN ALREADY For couples with obstructive azoospermia, MESA (epididymal sperm) and TESE (testicular sperm) have generally been assumed to be equivalent for use in ICSI. But this assumption has never been confirmed, and this view has important clinical and basic scientific consequences. STUDY DESIGN, SIZE, DURATION This was a retrospective study of a consecutive cohort of 374 men with obstructive azoospermia and normal spermatogenesis, who underwent IVF and ICSI using either epididymal sperm or testicular sperm in the period 2000-2009. PARTICIPANTS/MATERIALS, SETTING, METHODS The study included men undergoing MESA or TESE at St. Lukes Hospital for obstructive azoospermia due to CBAVD or vasectomy. MAIN RESULTS AND THE ROLE OF CHANCE A total of 280 couples underwent MESA and 94 underwent TESE with ICSI. The live birth rate was 39% after MESA-ICSI and 24% after TESE-ICSI. The MESA-ICSI cycles also resulted in a significantly higher implantation rate and significantly higher clinical and ongoing pregnancy rates than the TESE-ICSI cycles. There was no significant difference in results between fresh or frozen sperm for both MESA and TESE. When adjusted for the available confounders, the odds ratio for live birth was significantly in favour of MESA-ICSI versus TESE-ICSI (OR 1.82; 95% CI 1.05-3.67). The only significant confounders were female age and ovarian reserve. LIMITATIONS, REASONS FOR CAUTION This is a retrospective cohort study and not a randomized clinical trial. WIDER IMPLICATIONS OF THE FINDINGS Our study suggests that some aspect of sperm maturation after the sperm leaves the testicle to enter the epididymis is required for the most optimal results, even when ICSI is used for fertilization. STUDY FUNDING/COMPETING INTERESTS No funding was used and there are no competing interests.


Tijdschrift voor Urologie | 2014

8 De spermakwaliteit bij gevaccineerde mannen na bof-geassocieerde orchitis

M. Uijldert; A. Meissner; A.A. de Melker; M. van Wely; Corien Swaan; M. van der Sande; F. van der Veen; Sjoerd Repping

SamenvattingBij 3-38% van de mannen met een bof-infectie treedt een orchitis op, hetgeen kan leiden tot verminderde spermakwaliteit en daarmee tot vruchtbaarheidsproblemen.


Archive | 2011

Pharmacology of Sexual Function

A. Meissner; Martin C. Michel

Human sexual function involves a complex interaction between the central nervous system (CNS) and peripheral organs. The CNS receives and integrates tactile, olfactory, auditory, visual, and mental stimuli to regulate various domains of sexual function. This chapter will focus on three aspects of sexual function, that is, sexual desire/arousal and, in males, erection and ejaculation. While the manipulation of desire by definition requires drug effects on central nervous function, disorders of erection and ejaculation can potentially be addressed by both centrally and peripherally acting drugs. Our emphasis will be on drug mechanisms, which already are available clinically and/or are currently in clinical development. Potential issues related to ovulation and spermatogenesis will not be discussed.


Human Reproduction | 2012

Human testis-derived embryonic stem cell-like cells are not pluripotent, but possess potential of mesenchymal progenitors

J.V. Chikhovskaya; Martijs J. Jonker; A. Meissner; Timo M. Breit; Sjoerd Repping; A.M.M. van Pelt


Human Reproduction | 2016

Prediction model for live birth in ICSI using testicular extracted sperm

A.M. Meijerink; M. Cissen; M.H. Mochtar; Kathrin Fleischer; I. Thoonen; A.A. de Melker; A. Meissner; Sjoerd Repping; Didi D.M. Braat; M. van Wely; Liliana Ramos


Human Reproduction | 2013

Session 32: Stem cells and translational research

Richard A. Anderson; Marie McLaughlin; D.C. Woods; Jonathan L. Tilly; Evelyn E. Telfer; I. Virant-Klun; M. Stimpfel; B. Cvjeticanin; E. Vrtacnik-Bokal; T. Skutella; C. Beyazyurek; C.G. Ekmekci; N. Gulum; H.A. Tac; S. Kahraman; J. Cheng; Jing Su; Lijun Ding; Guijun Yan; Yali Hu; S. Hendriks; E.A.F. Dancet; A. Meissner; F. van der Veen; M.H. Mochtar; Sjoerd Repping; Ozgur Oktem; M. Muftuoglu; Filiz Senbabaoglu; Bulent Urman


Fertility and Sterility | 2016

Behavioral, cognitive, and motor performance and physical development of five-year-old children who were born after intracytoplasmic sperm injection with the use of testicular sperm.

Aukje M. Meijerink; Liliana Ramos; Anjo J.W.M. Janssen; Nienke M. Maas–van Schaaijk; A. Meissner; Sjoerd Repping; M.H. Mochtar; Didi D.M. Braat; Kathrin Fleischer

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M.H. Mochtar

University of Amsterdam

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S Hendriks

University of Amsterdam

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Didi D.M. Braat

Radboud University Nijmegen

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Kathrin Fleischer

Radboud University Nijmegen

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Liliana Ramos

Radboud University Nijmegen

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M Hessel

Radboud University Nijmegen

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M. van Wely

University of Amsterdam

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