Search results for "embryonic structures"
showing 10 items of 623 documents
Female obesity increases the risk of miscarriage of euploid embryos.
2020
Objective To determine whether female body mass index (BMI) is associated with an increased risk of miscarriage after euploid embryo transfer. Design A retrospective, observational, multicenter cohort study. Setting University-affiliated in vitro fertilization center. Patient(s) In this study, 3,480 cycles of in vitro fertilization with preimplantation genetic testing for aneuploidy (PGT-A) in the blastocyst stage and euploid embryo transfer were divided into four groups according to patient BMI. Intervention(s) In vitro fertilization with PGT-A. Main Outcome Measure(s) The primary outcome was the miscarriage rate, which included both biochemical and clinical miscarriages. Secondary outcome…
Automatic time-lapse instrument is superior to single-point morphology observation for selecting viable embryos: retrospective study in oocyte donati…
2016
Objective To correlate the different categories provided by a commercial diagnostic test with blastocyst formation, quality, implantation potential, and ongoing pregnancy (OPR) for the purpose of validating the automatic annotations and the classification algorithm. Design Observational, retrospective, multicenter cohort study. Setting University-affiliated private IVF center. Patient(s) A total of 3,002 embryos, including 521 transferred embryos with known implantation, from 626 IVF cycles that were incubated in a conventional incubator and monitored with an automatic time-lapse test. Interventions(s) None. Main Outcome Measure(s) Embryo selection was based on morphology and the classifica…
Morphokinetic analysis and embryonic prediction for blastocyst formation through an integrated time-lapse system.
2015
Objective To describe the events associated with the blastocyst formation and implantation that occur in embryos during preimplantation development based on the largest sample size ever described with time-lapse monitoring. Design Observational, retrospective, single-center clinical study. Setting University-affiliated private IVF center. Patient(s) A total of 7,483 zygotes from 990 first treatments of intracytoplasmic sperm injection (ICSI; 627 of oocyte donor vs. 363 autologous oocyte cycles), of which 832 blastocysts were transferred. Intervention(s) No patient intervention. Embryos were cultured in a time-lapse monitoring system, and the embryos were transferred on day 5 after ICSI. Emb…
Theory about the Embryo Cryo‐Treatment
2017
Background To create hypothesis, which can give a logical explanation related to the benefits of freezing/thawing embryos. Cryopreservation is not only a technology used for storing embryos, but also a method of embryo treatment that can potentially improve the success rate in infertile couples. Methods From the analysis of multiple results in assisted reproductive technology, which have no satisfactory explanation to date, we found evidence to support a ‘therapeutic’ effect of the freezing/thawing of embryos on the process of recovery of the embryo and its subsequent implantation. Results Freezing/thawing is a way to activate the endogenous survival and repair responses in preimplantation …
Identification and Characterization of Extracellular Vesicles and Its DNA Cargo Secreted During Murine Embryo Development
2020
Extracellular vesicles (EVs) are known to transport DNA, but their implications in embryonic implantation are unknown. The aim of this study was to investigate EVs production and secretion by preimplantation embryos and assess their DNA cargo. Murine oocytes and embryos were obtained from six- to eight-week-old females, cultured until E4.5 and analyzed using transmission electron microscopy to examine EVs production. EVs were isolated from E4.5-day conditioned media and quantified by nanoparticle tracking analysis, characterized by immunogold, and their DNA cargo sequenced. Multivesicular bodies were observed in murine oocytes and preimplantation embryos together with the secretion of EVs t…
Knowledge, Awareness And Perceptions Of Females On Clandestine Abortion In Kintampo North Municipality, Ghana
2016
Clandestine Abortion will continue to be an integral part of human society as long as people continue to accept and engage in sexual activities without being prepared to give birth. Despite the risks (death and other health complication) involved in clandestine abortion, people continue to engage in the act. The central inquiry is; why do people continue to do clandestine abortions despite its associated risk? Do people have knowledge on abortion concerning its legalities and associated risks? This paper thus seeks to clarify the above questions by examining the knowledge, awareness and perceptions of females on abortion, with focus on clandestine abortion in the Kintampo North Municipality…
09-P102 Somitogenesis and development of primary motor neurons: The role of the homeobox uncx4.1
2009
The gene uncx4.1 is a paired-type homeobox transcription factor, expressed during zebrafish embryonic development in branchial arches, somites, CNS and pronephric ducts. In particular, the expression at the somite level is detectable from 5ss stage and becomes progressively posteriorly and ventrally restricted to the presumptive myoblast cells in later stages. Interestingly, the progressive restriction of uncx4.1 activity anticipates and accompanies the appearance of the first outgrowing primary motor axons. Indeed, after uncx4.1 expression is not detected anymore in medial somitic cells, a ventrally projecting CaP motor axons emerge from the ventro-lateral spinal cord. In relation with mus…
Self-organised symmetry breaking in zebrafish reveals feedback from morphogenesis to pattern formation
2019
A fundamental question in developmental biology is how the early embryo breaks initial symmetry to establish the spatial coordinate system later important for the organisation of the embryonic body plan. In zebrafish, this is thought to depend on the inheritance of maternal mRNAs [1–3], cortical rotation to generate a dorsal pole of beta-catenin activity [4–8] and the release of Nodal signals from the yolk syncytial layer (YSL) [9–12]. Recent work aggregating mouse embryonic stem cells has shown that symmetry breaking can occur in the absence of extra-embryonic tissue [19,20]. To test whether this is also true in zebrafish, we separated embryonic cells from the yolk and allowed them to deve…
Neuromesodermal Progenitors are a Conserved Source of Spinal Cord with Divergent Growth Dynamics
2018
AbstractDuring gastrulation, embryonic cells become specified into distinct germ layers. In mouse, this continues throughout somitogenesis from a population of bipotent stem cells called neuromesodermal progenitors (NMps). However, the degree self-renewal is associated with NMps in the fast-developing zebrafish embryo is unclear. With a genetic clone tracing method, we labelled early embryonic progenitors and find a strong clonal similarity between spinal cord and mesoderm tissues. We then followed individual cell lineages by light-sheet imaging and reveal a common neuromesodermal lineage contribution to a subset of spinal cord tissue across the anterior-posterior body axis. An initial popu…
La hipoxia fetal valorada mediante métodos objetivos y su relación con el Factor de crecimiento del Endotelio Vascular (VEGF) en gestaciones gemelare…
2008
Introducción Para el correcto desarrollo placentario y fetal, se requieren los procesos de vasculogénesis y angiogénesis que están regulados entre otros por la familia VEGF y el Factor de crecimiento placentario (PlGF) que traducen sus señales uniendose a sus receptores transmembrana, el VEGFR1 y 2. El VEGFR1 tiene una forma soluble ( s.Flt-1) que actúa como un inhibidor del VEGF y del PlGF . El VEGF-A es el principal regulador de la angiogénesis siendo el VEGF-121 y VEGF-165 las 2 isoformas más predominantes e importantes, y estando su expresión regulada por la hipoxia. La hipoxia debida a insuficiencia placentaria se observa en gestaciones gemelares con discrepancia ponderal entre los fet…