Search results for "Embryon"
showing 10 items of 988 documents
Female pelvic congenital malformations. Part I: embryology, anatomy and surgical treatment.
2011
This review covers the most important female congenital pelvic malformations. The first part focuses on the embryological development of the urogenital and anorectal apparatus, morphological features, and the diagnostic and surgical approach to abnormalities. Comprehension of the embryological development of the urogenital and anorectal apparatus is essential to understand the morphology of congenital pelvic abnormalities and their surgical treatment. Congenital pelvic malformations are characterized by specific common features; the severity of which often subverts the pelvic morphology completely and makes it difficult to comprehend before surgery. The development of imaging, mainly magnet…
Assessment of the implantation of day-2 human embryos by morphometric nonsubjective parameters
2014
Objective: To demonstrate the usefulness of image analysis in designing objective embryonic morphometric variables. Design: Retrospective study of 214 top-quality day-2 embryo photographs from 50 double-embryo transfers resulting in no pregnancy (group 0) and 57 resulting in twin pregnancy (group 1). Setting: Human reproduction unit. Patient(s): Study of 107 in vitro fertilization intracytoplasmic sperm injection (IVF ICSI) cycles in women age<36 years with doubleembryo transfer of top-quality embryos. Only the first cycle of IVF ICSI was included. Intervention(s): Standard IVF ICSI protocols. Main Outcome Measure(s): The embryo photographs were analyzed using the ImageJ program. The effect…
Limited implantation success of direct-cleaved human zygotes: a time-lapse study.
2012
Objective To evaluate embryos with direct cleavage (≤5 hours) from two to three cells (DC2–3) and correlate this morphokinetic parameter to implantation and ongoing pregnancy. Design Clinical multicenter retrospective study. Setting Private in vitro fertilization (IVF) centers. Patient(s) From three clinics, a total of 979 treatments including 5,225 embryos using autologous or donated oocytes, of which 1,659 embryos were transferred. Intervention(s) None. Main Outcome Measure(s) Clinical pregnancy confirmed by ultrasound in week 7. Result(s) Of the total embryo cohort, 715 (13.7%) underwent direct cleavage from two to three cells, 1,659 embryos were transferred to recipients, and 109 of the…
Collapse of blastocysts is strongly related to lower implantation success: a time-lapse study.
2015
Study question Is there an association between blastocyst collapse patterns and implantation potential? Summary answer Embryos that exhibit collapse are as likely to hatch as those that do not, but are less likely to implant and should not be replaced if alternatives are available. What is known already Studies of blastocyst collapse in different species of mammals have found that most blastocysts, that experience consecutive weak contractions, hatch successfully whereas those that exhibit strong contractions or collapse, fail to hatch. Study design, size, duration Retrospective cohort study. Seven hundred and fifteen transferred blastocysts were analyzed from July 2012 to May 2013. Partici…
Antral follicle count (AFC) can be used in the prediction of ovarian response but cannot predict the oocyte/embryo quality or the in vitro fertilizat…
2007
To verify whether the antral follicle count (AFC) could predict ovarian response, oocyte/embryo quality, and IVF outcome.Prospective study.Instituto Universitario-Instituto Valenciano de Infertilidad, Valencia, Spain.One thousand seventy-four donors and 975 oocyte recipient cycles.Controlled ovarian hyperstimulation (COH), endometrial preparation, IVF/intracytoplasmic sperm injection, ET.COH and oocyte/embryo quality parameters and IVF outcome.We observed lower E(2) levels and fewer mature retrieved oocyte numbers among donors who showed an AFC that was10. These donors also showed significantly higher cancellation and no-donation rates; poor and/or insufficient response was the principal ca…
Physiological changes in glutathione metabolism in foetal and newborn rat liver
1991
Glutathione metabolism was studied in isolated hepatocytes from foetal, newborn and adult rats. The GSH/GSSG ratio decreased 15-20-fold through the foetal-neonatal-adult transition. This was mainly due to an increase in GSSG. All enzyme activities involved in the glutathione redox cycle tend to increase during that transition, but the relative increases in glutathione peroxidase and glutathione S-transferase were 3-5 times those of glutathione reductase or glucose-6-phosphate dehydrogenase. GSH synthesis from methionine as a sulphur source was 6 times lower in foetal than in adult hepatocytes. However, when N-acetylcysteine was used as a sulphur donor to by-pass the cystathionine pathway, t…
The role of gonadotropin-releasing hormone in murine preimplantation embryonic development.
1999
Previous studies have established the presence of an extrahypothalamic GnRH in a variety of tissues. GnRH receptor is known to be present in the placenta, which produces and secretes the decapeptide from the very early stages of placentation. We hypothesized that GnRH may play a role in the preimplantation development of embryos. To examine this hypothesis, we assessed GnRH and GnRH receptor messenger RNA (mRNA; RT-PCR) and protein expression (Immunohistochemistry) in preimplantation murine embryos at various developmental stages. Furthermore, preimplantation murine embryos were cultured with GnRH agonist and antagonist in vitro to assess the influence of GnRH analogs on embryo development.…
Towards an ideal source of mesenchymal stem cell isolation for possible therapeutic application in regenerative medicine.
2014
Background. The possibility of obtaining mesenchymal stem cells (MSCs) from fetal tissue such as amniotic fluid, chorionic villi and placenta is well-known and a comparison between MSCs originating in different sources such as fetal tissue and those from bone marrow in terms of yield and function is a topical issue. The mesenchymal stem cells isolated from bone marrow are well-characterized. Unfortunately the low quantitative yield during isolation is a major problem. For this reason, other tissue sources for MSCs are of paramount importance. Conclusion. In this review, starting from a description of the molecular and cellular biology of MSCs, we describe alternative sources of isolation ot…
Übertragung von Verhaltensweisen durch Transplantation von Anlagen neuroanatomischer Strukturen bei Amphibienlarven
2010
By replacing parts of the neural plate (prospective medulla oblongata) of Triturus vulgaris by neural ectoderm of Xenopus laevis larval chimaeras were obtained, which showed donorlike rhythmical movements of distinct parts of the visceral musculature according to the place of implantation. Especially the branchial region with its external gills showed rhythmical movements and is the special object of this investigation.
Inhibition of Histone Deacetylase Activity in Human Endometrial Stromal Cells Promotes Extracellular Matrix Remodelling and Limits Embryo Invasion
2011
Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs). The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expressio…