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A Coruña, Spain

Buffone M.G.,CONICET | Calamera J.C.,Laboratorio Of Estudios En Reproduccion Ler | Brugo-Olmedo S.,Centro Medico Seremas | De Vincentiis S.,Centro Medico Seremas | And 5 more authors.
Fertility and Sterility | Year: 2012

Objective: To investigate the correlation between sperm superoxide dismutase (SOD) content and motility recovery after thawing of cryopreserved human sperm, based on the rationale that this antioxidant enzyme provides protection against reactive oxygen species-induced damage during cryopreservation. Design: Prospective study. Setting: Private infertility institute and university-based research laboratory. Patient(s): Forty-two consenting normozoospermic patients consulting for infertility. Intervention(s): The SOD content was measured in sperm from unfractionated samples and in sperm recovered from the pellet fraction obtained after discontinuous density gradient centrifugation. Main Outcome Measure(s): Sperm motility was evaluated post-thaw in the two sets of samples and motility recovery was plotted against the sperm SOD content to determine their correlation. Result(s): There was a significant positive correlation between motility recovery after thawing and SOD content in sperm from the 90% gradient pellet containing highly purified mature sperm. There was also a significant negative correlation between motility after thawing and SOD content in the unfractionated sample. Conclusion(s): The positive correlation between post-thaw motility recovery and SOD content in mature spermatozoa provides a good predictor of post-thaw motility recovery after cryopreservation. © 2012 American Society for Reproductive Medicine, Published by Elsevier Inc. Source

Cheuqueman C.,University of the Frontier | Loren P.,University of the Frontier | Arias M.,University of the Frontier | Risopatron J.,University of the Frontier | And 4 more authors.
Theriogenology | Year: 2015

Stress tolerance can be induced in embryos by oocyte exposure to hydrostatic pressure, osmotic agents, heat shock, or reactive oxygen species. This study assessed the effects of exposing bovine oocytes to a nitric oxide (NO) donor, sodium nitroprusside (SNP), on subsequent invitro embryo production, embryo quality and the expression of genes involved in NO production (iNOS, eNOS, and nNOS), stress tolerance (HSP70 and HSP90), oxidative stress (HIF1A and PRDX5), and apoptosis (BCL2A1). Invitro mature oocytes were incubated with SNP (control, 10-6M, 10-5M, and 10-4M) for 1hour before invitro fertilization, and cultured until Day 7. Cleavage and blastocyst rates were recorded. Next, embryo quality (ratio of inner cell mass to total cell number) and relative gene expression of iNOS, eNOS, nNOS, HSP70, HSP90, HIF1A, PRDX5, and BCL2A1 were determined in expanded blastocysts. Cleavage rates were significantly lower for 10-4M SNP compared with the control and 10-5M SNP treatments (77±7.1%, 82±8.4%, and 84.9±4.1%, respectively). Total blastocyst rates were lower in the 10-4M SNP group relative to the control group (26.2±4.9% and 34.1±7.8%, respectively). Embryo quality was similar among the groups. However, our relative gene expression analysis revealed the downregulation of endothelial oxide nitric synthase messenger RNA in expanded blastocysts in all the treatment groups compared with the control treatment. These results suggest that the short-term exposure of mature bovine oocytes to a NO donor does not induce their stress tolerance and has no beneficial effect on the invitro embryo production of bovine embryos. © 2015 Elsevier Inc. Source

Cheuqueman C.,University of the Frontier | Arias M.E.,University of the Frontier | Risopatron J.,University of the Frontier | Felmer R.,University of the Frontier | And 3 more authors.
Andrologia | Year: 2015

Gamete co-incubation generates high free radical levels surrounding growing zygotes which may impair subsequent embryo viability. Melatonin eliminates a wide variety of free radicals; hence, we tried to improve in vitro embryo production by adding melatonin to in vitro fertilisation (IVF) media in high (Exp. 1) and low concentrations (Exp. 2), and we evaluated its effect on bull sperm function during IVF co-incubation time (Exp. 3). In Experiment 1, we supplemented IVF media culture with 0.01, 0.1 and 1 mmol of melatonin, along with a no melatonin control group. In Experiment 2, melatonin levels were reduced to 10, 100 and 1000 nmol, with a no melatonin control group. In Experiment 3, spermatozoa were incubated in IVF media with melatonin (as Exp. 2) and functional parameters were analysed at 0, 4 and 18 h. In Experiment 1, only 1 mmol melatonin showed lesser blastocyst rates than control (C: 23.2 ± 6.7% versus 1 mmol: 2.0 ± 1.7%). In Experiment 2, no statistical differences were found in cleavage percentage, blastocyst percentage and total cell count for any melatonin treatment. In Experiment 3, sperm samples with 1000 nmol melatonin had a significantly higher wobbler (WOB) coefficient, a lower percentage of intact acrosomes, a lower percentage of viable spermatozoa with ROS, greater DNA fragmentation and higher DNA oxidation than controls. Total fluorescence intensity for ROS at 10 nmol melatonin was significantly greater than controls (P < 0.05). IVF media with 1 mmol melatonin is deleterious for embryo development, and in lower concentrations, it modulated sperm functionality, but had no effects on embryo production. © 2014 Blackwell Verlag GmbH. Source

Esteves S.C.,ANDROFERT andrology and Human Reproduction Clinic | Zini A.,McGill University | Aziz N.,Liverpool Womens Hospital | Alvarez J.G.,Centro ANDROGEN | And 2 more authors.
Urology | Year: 2012

In 2010, the World Health Organization established new reference values for human semen characteristics that are markedly lower than those previously reported. Despite using controlled studies involving couples with a known time to pregnancy to establish the new limits, the reference studies are limited with regard to the population analyzed and the methods used for semen evaluation. The present review discusses concerns related to the new reference values for semen characteristics, including the effect on patient referral, diagnosis, and treatment of recognized conditions, such as varicocele, and on the indications for assisted reproductive technologies. © 2012 Elsevier Inc. Source

Kocer A.,French Institute of Health and Medical Research | Henry-Berger J.,French Institute of Health and Medical Research | Noblanc A.,French Institute of Health and Medical Research | Champroux A.,French Institute of Health and Medical Research | And 13 more authors.
Free Radical Biology and Medicine | Year: 2015

Normal embryo and foetal development as well as the health of the progeny are mostly dependent on gamete nuclear integrity. In the present study, in order to characterize more precisely oxidative DNA damage in mouse sperm we used two mouse models that display high levels of sperm oxidative DNA damage, a common alteration encountered both in in vivo and in vitro reproduction. Immunoprecipitation of oxidized sperm DNA coupled to deep sequencing showed that mouse chromosomes may be largely affected by oxidative alterations. We show that the vulnerability of chromosomes to oxidative attack inversely correlated with their size and was not linked to their GC richness. It was neither correlated with the chromosome content in persisting nucleosomes nor associated with methylated sequences. A strong correlation was found between oxidized sequences and sequences rich in short interspersed repeat elements (SINEs). Chromosome position in the sperm nucleus as revealed by fluorescent in situ hybridization appears to be a confounder. These data map for the first time fragile mouse sperm chromosomal regions when facing oxidative damage that may challenge the repair mechanisms of the oocyte post-fertilization. © 2015 Elsevier Inc. All rights reserved. Source

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