Search results for "Embryo"
showing 10 items of 1872 documents
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…
Children born after autotransplantation of cryopreserved ovarian tissue. a review of 13 live births.
2011
Abstract Introduction. Premature ovarian failure (POF) can occur naturally at an early age or be due to iatrogenic agents. Indeed, ovaries are very sensitive to cytotoxic treatment, especially to radiation and alkylating agents. Methods. Several options are currently available to preserve fertility in cancer patients and allow them to conceive when they have overcome their disease: embryo cryopreservation, oocyte cryopreservation, and ovarian tissue cryopreservation. Cryopreservation of ovarian tissue is the only option available for pre-pubertal girls and women who cannot delay the start of chemotherapy. Findings. Since the first live birth after autotransplantation of cryopreserved ovaria…
Hormonal and molecular characterization of follicular fluid, cumulus cells and oocytes from pre-ovulatory follicles in stimulated and unstimulated cy…
2012
background: The use of ovarian stimulation, to stimulate a multi-follicular response for assisted reproduction treatments, may force the production of oocytes from follicles that do not reach optimal maturation, possibly yielding oocytes that are not fully competent. The present study aimed to define the follicular environment and oocyte competence of unstimulated pre-ovulatory follicles, to compare it with that of similar-sized stimulated follicles. For this purpose, we analyzed the follicular hormonal milieu, the oocyte meiotic spindle, the embryo development and the cumulus cells gene expression (GE) profiles. methods and results: The study population was divided in two groups: (i) 42 oo…
Genetic polymorphisms of serotonin transporter and receptor 1A could influence success during embryo implantation and maintenance of pregnancy
2012
Objective To explore whether serotonin-related gene polymorphisms influence clinical outcomes of IVF treatment in recipients using donated oocytes. Design Nested case-control study. Setting University-affiliated infertility clinic. Patient(s) Two hundred forty-five women undergoing IVF treatment with donated oocytes. Intervention(s) None. Main Outcome Measure(s) Genotype and haplotype analysis of the serotonin transporter-linked polymorphic region (5-HTTLPR), rs1800532, rs6295, rs6313, and rs3813929, between recipients grouped according to the results of the oocyte donation for IVF treatment. Result(s) No differences were found between genotype distribution of the tryptophan hydroxylase 1, …
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…
Changes in metabolism of inorganic polyphosphate in rat tissues and human cells during development and apoptosis
1997
Age-dependent studies show that the amount of inorganic polyphosphate in rat brain strongly increases after birth. Maximal levels were found in 12-months old animals. Thereafter, the concentration of total polyphosphate decreases to about 50%. This decrease in the concentration of total polyphosphate is due to a decrease in the amount of insoluble, long-chain polyphosphates. The amount of soluble, long-chain polyphosphates does not change significantly in the course of ageing. In rat embryos and newborns, mainly soluble polyphosphates could be detected. In rat liver, the age-dependent changes are less pronounced. The changes in polyphosphate level are accompanied by changes in exopolyphosph…
Effects of ageing on peroxidase activity and localization in radish (Raphanus sativus L.) seeds.
2010
Peroxidase activity was assayed in crude extracts of integument, cotyledons and embryo axis of radish seeds, deteriorated under accelerated ageing conditions. Over five days of ageing, in which germination decreased from 100 to 52%, the enzyme activity in integument was higher than that in other seed parts, increasing in the first days of ageing and then decreasing sharply in extremely aged seeds. Polyacrylamide gel electrophoresis analysis showed four peroxidase isoenzymes with MM of 98, 52.5, 32.8 and 29.5 kDa in the embryo axis of unaged seeds, and only the 32.8 and 29.5 kDa MM isoforms in the integument and cotyledons. In these parts of the seed, only the 29.5 kDa MM isoenzyme increased…
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…
Morphological and biochemical effects of glucocorticoids in chick embryo hepatocytes during development
1988
Abstract The administration in ovo of hydrocortisone-21-phosphate caused, in chick embryo liver, a reduction of the number of hepatocytes which can be isolated from 1 mg dry weight of liver and a marked increase of their size. Moreover, the treatment diminished the incorporation of thymidine into acid-insoluble fraction in these cells whilst it augmented the content of protein, RNA, DNA and the level of thymidine kinase/cell. These effects were highest at 8–10 days, then declined with the age, disappearing after 18th day of incubation. Similar effects were obtained by injecting other glucocorticoids or ACTH. Combined treatment with metopirone abolished the effects found with ACTH, but did n…