Search results for "Oocyte activation"
showing 5 items of 5 documents
Kinetics of the early development of uniparental human haploid embryos
2016
Objective: To describe morphokinetically the early development of human haploid parthenotes and androgenotes and to compare them with euploid embryos. Design: Experimental study of kinetics. Setting: University-affiliated private fertility center. Patient(s): Experimental haploid parthenotes and androgenotes. Intervention(s): Kinetic study of early development (up to eight cells) of 8 parthenotes, 10 androgenotes, and 20 euploid embryos. Main Outcome Measure(s): Timing of the first seven cleavages determined according to embryo origin, then calculation of the duration of the second and third cell cycles (cc2 and cc3) of whole embryos and individual cells. Result(s): Parthenotes and androgen…
Onset of DNA synthesis in experimentally activated ascidian eggs
1994
DNA synthesis was studied autoradiographically in unfertilized ascidian eggs (Ascidia malaca and Ciona intestinalis) that had been artificially activated by a K+-free external medium or a Ca-ionophore. Naked eggs of A. malaca were incubated in K+-free seawater that contained [3H]-thymidine for 30 min, and naked eggs of C. intestinalis were incubated in seawater supplemented with a Ca-ionophore and [3H]-thymidine for 15 min. The observations revealed limited activation in eggs treated with K+-free seawater. Activation consisted of surface modifications and the onset of DNA synthesis. Incorporation of [3H]-thymidine was detected in female nuclei of treated eggs which had not ejected their pol…
Embryo morphokinetics analysis and reproductive outcomes with assisted oocyte activation by a calcium ionophore after prior fertilization failure. A …
2020
Abstract Background Fertilization failure or low fertilization rate after ICSI is around 1–3% in IVF treatments. Several strategies have been studied in order to bypass the lack of activation. The aim of this study is to evaluate embryo morphokinetics and reproductive outcomes after intracytoplasmic sperm injection (ICSI) with assisted oocyte activation (AOA) using a calcium ionophore (CaI) in patients with previous fertilization failure or low fertilization rate (under 30%) and severe male factor. Methods Multicentric retrospective cohort study including 70 patients with fertilization failure or low fertilization rate and severe male factor (sperm concentration under 1 million/mL) who unde…
Successful pregnancy and childbirth after intracytoplasmic sperm injection with calcium ionophore oocyte activation in a globozoospermic patient
2007
Objective To check the effectiveness of intracytoplasmic sperm injection (ICSI) combined with assisted oocyte activation (AOA) in a globozoospermic patient. Design Case report. Setting Instituto Valenciano de Infertilidad, Valencia, Spain. Patient(s) A patient with globozoospermia. Intervention(s) ICSI was administered in 14 oocytes. ICSI combined with AOA, in which a small amount of calcium was injected followed by calcium ionophore exposure, was done in 9 oocytes. Main Outcome Measure(s) Fertilization rate and embryo quality was assessed in both groups. Result(s) Chemical activation increased fertilization rate (55.6% vs. 35.7%) and the number of embryos with less multinucleation on day 2…
Intracellular activation of ovastacin mediates pre-fertilization hardening of the zona pellucida
2017
Study question How and where is pro-ovastacin activated and how does active ovastacin regulate zona pellucida hardening (ZPH) and successful fertilization? Study finding Ovastacin is partially active before exocytosis and pre-hardens the zona pellucida (ZP) before fertilization. What is known already The metalloproteinase ovastacin is stored in cortical granules, it cleaves zona pellucida protein 2 (ZP2) upon fertilization and thereby destroys the ZP sperm ligand and triggers ZPH. Female mice deficient in the extracellular circulating ovastacin-inhibitor fetuin-B are infertile due to pre-mature ZPH. Study design, samples/materials, methods We isolated oocytes from wild-type and ovastacin-de…