Publications by authors named "Eric Gonzalez-Merino"

7 Publications

  • Page 1 of 1

Letrozole-associated controlled ovarian hyperstimulation in breast cancer patients versus conventional controlled ovarian hyperstimulation in infertile patients: assessment of oocyte quality related biomarkers.

Reprod Biol Endocrinol 2019 Jan 3;17(1). Epub 2019 Jan 3.

Fertility Clinic, Department of Obstetrics and Gynecology, CUB-Hôpital Erasme, Université Libre de Bruxelles (ULB), Route de Lennik 808, Brussels, Belgium.

Background: Fertility preservation (FP) protocols in case of breast cancer (BC) include mature oocyte cryopreservation following letrozole associated controlled ovarian hyperstimulation (Let-COH). To date, the impact of Let-COH on the follicular microenvironment has been poorly investigated, although a high androgen/estrogen ratio was previously associated with low oocyte quality.

Methods: In this prospective study, follicular fluid (FF) steroid levels (estradiol, testosterone, progesterone) and cumulus cell (CC) gene expression related to oocyte quality (HAS2, PTGS2, GREM1) were compared between 23 BC patients undergoing Let-COH for FP and 24 infertile patients undergoing conventional COH without letrozole. All patients underwent an antagonist COH cycle, and ovulation was triggered with hCG or GnRHa in both groups.

Results: FF estradiol levels were significantly lower while testosterone levels were significantly higher in the study group compared to controls irrespective of the trigger method. However, estradiol levels increased significantly with GnRHa triggering compared to hCG in the study group (median = 194.5 (95.4-438) vs 64.4 (43.8-152.4) ng/ml, respectively, p < 0.001), but not in the control group (median = 335.5 (177.5-466.7) vs 354 (179-511) ng/ml, respectively). After hCG trigger, Cumulus cell (CC) gene expression was lower in the study group compared to the control group, and difference was significant for PTGS2. Conversely, CC gene expression of PTGS2 and GREM1 was significantly higher in the study group compared to controls when ovulation was triggered with GnRHa.

Conclusions: Let-COH triggered with hCG may negatively impact oocyte quality. However, ovulation triggering with GnRHa may improve the oocyte microenvironment and cumulus cell genes expression in Let-COH, suggesting a positive impact on oocyte quality in breast cancer patients.

Trial Registration: Clinicaltrials.gov - NCT02661932 , registered 25 January 2016, retrospectively registered.
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http://dx.doi.org/10.1186/s12958-018-0443-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6318989PMC
January 2019

Aneuploidy study in sperm and preimplantation embryos from nonmosaic 47,XYY men.

Fertil Steril 2007 Sep 22;88(3):600-6. Epub 2007 May 22.

Fertility Clinic, Erasme Hospital and Research Laboratory on Human Reproduction, Faculty of Medicine, French Speaking Free University of Brussels, Brussels, Belgium.

Objective: To determine gonosomal and autosomal aneuploidy rate in sperm and preimplantation embryos from nonmosaic 47,XYY males.

Design: Sperm and blastomere analysis by fluorescence in situ hybridization.

Setting: Fertility clinic, academic hospital.

Patient(s): Two 47,XYY men undergoing preimplantation genetic diagnosis (PGD) and eight 46,XY males distributed in two control groups (fertile and infertile).

Intervention(s): Sperm-sample collection for fluorescence in situ hybridization and PGD.

Main Outcome Measure(s): Aneuploidy frequencies for chromosomes X, Y, 13, 16, 18, 21, and 22 in sperm and embryos.

Result(s): Patients with 47,XYY presented global sperm gonosomal and autosomal aneuploidy frequency of 37.23%-37.80%, with XY disomy being the most frequent abnormality (16.70%-19.01%). This aneuploidy rate was statistically significantly different from that found in both 46,XY infertile controls (1.07%) and 46,XY fertile controls (1.04%). In total, 47 preimplantation embryos were analyzed, of which 32 were classified as normal (68%) and 15 as aneuploid (32%). Among the abnormal embryos, 9 presented gonosomal abnormalities, and 6, autosomal abnormalities.

Conclusion(s): High rate of gonosomal and autosomal aneuploidy was observed in sperm and preimplantation embryos from nonmosaic 47,XYY males. The offspring of this category of patients may be at higher risk of chromosomal abnormalities, and therefore PGD can be suggested to these patients.
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http://dx.doi.org/10.1016/j.fertnstert.2006.12.020DOI Listing
September 2007

Comparison of the validity of preimplantation genetic diagnosis for embryo chromosomal anomalies by fluorescence in situ hybridization on one or two blastomeres.

Genet Test 2004 ;8(1):69-72

Fertility Clinic and Laboratory of Research on Human Reproduction, Free University of Brussels, French Speaking, 1070 Brussels, Belgium.

Is it necessary to analyze two blastomeres in preimplantation genetic diagnosis (PGD) by fluorescence in situ hybridization (FISH) or is one blastomere enough, as suggested by some teams? We analyzed the sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), false positives (FP), false negatives (FN), and the efficiency (Eff) of FISH performed on one (Group I) or two (Group II) blastomeres. Ninety embryos were analyzed (day 3), 19 blastocysts were replaced (day 5), 64 embryos were reanalyzed (day 5), (Group I = 23; Group II = 41). No differences were observed between the two groups for all of the parameters considered, but one false negative was observed in Group I. Furthermore, two embryos from Group II, which had a discordant diagnosis at PGD (one blastomere being normal and one abnormal), were read as abnormal after reanalysis. The accidental biopsy of the normal blastomere could have lead to the selection of these 2 embryos for transfer, causing a misdiagnosis rate of 4.8%. We conclude that embryo reanalysis is a useful tool to test the reliability of PGD in each laboratory: that PGD on two blastomeres is safer because the practice of PGD on one blastomere can result in a false-negative misdiagnosis.
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http://dx.doi.org/10.1089/109065704323016058DOI Listing
November 2004

Incidence of chromosomal mosaicism in human embryos at different developmental stages analyzed by fluorescence in situ hybridization.

Genet Test 2003 ;7(2):85-95

Fertility Clinic, Department of Obstetrics and Gynaecology, and Laboratory of Research on Human Reproduction, Erasmus Hospital-ULB, Free University of Brussels, Belgium.

Chromosomal mosaicism has been reported in in vitro-cultured embryos at early cleavage stages, as well as in morulae and blastocysts. We have assessed the incidence and pattern of mosaicism during in vitro development of human embryos from early-cleavage stages to morula and blastocyst. Fifty spare embryos were fixed for fluorescence in situ hybridization (FISH) analysis for chromosomes X, Y, 13, 18, and 21 on days 2 or 3 (4- to 10-cell stage) (n = 16), on day 4 (morula stage) (n = 14), on day 5 (pre-expanded blastocyst) (n = 5), and the expanded blastocyst stages (n = 15). Blocked embryos (no cleavage observed within the last 24 hr) were not included. A total of 2367 cells were analyzed. Four early-cleavage stage embryos were found uniformly diploid; all of the others were mosaic for the chromosomes analyzed (mean diploid nuclei 48.3% +/- 28.7). All of the embryos at more advanced developmental stages, except one fully normal morula, had mosaic chromosome constitutions, with an increase in the percentage of diploid cells in morulae, pre-expanded, and expanded blastocysts, respectively (mean diploid nuclei 78.6% +/- 11.7, 66.0% +/- 20.8, 79.6% +/- 12.8), in comparison with earlier stages. Hypotheses about the origin of mosaicism and embryo regulation mechanisms will be discussed.
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http://dx.doi.org/10.1089/109065703322146768DOI Listing
April 2004

Higher degree of chromosome mosaicism in preimplantation embryos from carriers of robertsonian translocation t(13;14) in comparison with embryos from karyotypically normal IVF patients.

J Assist Reprod Genet 2003 Feb;20(2):95-100

Fertility Clinic and Laboratory of Research on Human Reproduction, Erasmus Hospital, Free University of Brussels, Belgium.

Purpose: To compare the frequency and the degree of mosaicism in human embryos from Robertsonian translocation (RT) t(13;14) carriers, with embryos from karyotypically normal IVF patients

Methods: FISH analysis of embryos from PGD cycles for RT t(13;14), with probes for chromosomes 13, 14, and 18 (Group I) and of embryos from karyotypically normal IVF patients with probes for chromosomes 13, 18, 21, X, and Y (Group II).

Results: The incidence of abnormal mosaic embryos was significantly higher in group I (38/51) as compared with group II (6/45) (chi2: P < 0.01). Furthermore, in group I the percentage of diploid cells per embryo was lower for chromosome 13 and 14 in comparison with 18, while in group II no differences were observed between the five chromosomes analyzed.

Conclusions: RT induces a high frequency of mosaicism specifically for the chromosomes implicated in the translocation; the analysis by FISH of two blastomeres is strongly recommended for these patients
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3455794PMC
http://dx.doi.org/10.1023/a:1021796226031DOI Listing
February 2003

Correlation between fluorescence in-situ hybridization analyses and in-vitro development to blastocyst stage of embryos from Robertsonian translocation (13;14) carriers.

Hum Reprod 2002 Nov;17(11):2957-62

Fertility Clinic Erasmus Hospital, French Speaking Free University of Brussels, Route de Lennik, 808, 1070 Brussels, Belgium.

Background: Little is known about the extent and timing of selection against the embryos that are carriers of unbalanced translocations.

Methods: Fluorescence in-situ hybridization (FISH) with probes for chromosomes 13, 14 and 18 was performed, mostly on day 3, on 69 human embryos which were then allowed to develop further in culture to day 5, from five carriers of Robertsonian translocation (RT) t(13;14).

Results: Twelve normal/balanced blastocysts were replaced in seven consecutive cycles (day 5). Three cycles resulted in clinical pregnancies. The proportion of blastocysts displaying a normal/balanced karyotype was 56%, while only the 20% of blocked embryos were normal/balanced (chi(2): P < 0.05). All the embryos analysed on day 5, except one, displayed mosaicism. The percentages of diploid cells for chromosomes 13 and 14 were significantly lower than for chromosome 18 (chromosome 13: 49.0 +/- 28.0; chromosome 14: 53.0 +/- 31.8; chromosome 18: 75.7 +/- 20.4; Mann-Whitney test: P < 0.01). The embryos displaying vertical line 62% of diploid cells for at least two of the three chromosomes analysed, more frequently reached the blastocyst stage (blocked embryos: blastocysts chromosome 13: 43.1 +/- 30.3, 64.9 +/- 29.0; chromosome 18: 64.9 +/- 29.0, 83.0 +/- 12.9; Mann-Whitney test: P < 0.01).

Conclusions: Normal/balanced embryos developed better but the proportion of abnormal blastocysts was still high. Preimplantation genetic diagnosis is recommended to select normal/balanced embryos from RT t(13;14) carriers.
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http://dx.doi.org/10.1093/humrep/17.11.2957DOI Listing
November 2002

Human fetuses are able to mount an adultlike CD8 T-cell response.

Blood 2002 Sep;100(6):2153-8

Laboratoire de Parasitologie, Faculté de Médecine and the Département de Génétique Médicale, Hôpital Erasme, Université Libre de Bruxelles, U.L.B. Route de Lennick 808, CP 616, B-1070 Brussels, Belgium.

Fetal/neonatal immune responses generally are considered to be immature and weaker than that of adults. We have studied the cord-blood T cells of newborns congenitally infected with Trypanosoma cruzi, the protozoan agent of Chagas disease. Our data demonstrate a predominant activation of CD8 T cells expressing activation markers and armed to mediate effector functions. The analysis of the T-cell receptor beta chain variable repertoire shows the oligoclonal expansion of these T lymphocytes, indicating that activation was driven by parasite antigens. Indeed, we have detected parasite-specific CD8 T cells secreting interferon-gamma after coincubation with live T cruzi. This response is enhanced in the presence of recombinant interleukin-15, which limits the T-cell spontaneous apoptosis. These findings point out that the fetal immune system is more competent than previously appreciated, since fetuses exposed to live pathogens are able to develop an adultlike immune CD8 T-cell response.
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September 2002
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