Search results for "mammalia"
showing 10 items of 304 documents
Timing of cell division in human cleavage-stage embryos is linked with blastocyst formation and quality
2012
Noninvasive markers of embryo quality are being sought to improve IVF success. The present study aimed to discover possible associations between embryo division kinetics in the cleavage stage, the subsequent ability of human embryos to reach the blastocyst stage and the resulting blastocyst morphology. A retrospective cohort study analysed 834 embryos from 165 oocyte donation couples using a time-lapse monitoring system that allowed the recording of the exact timings for key events related to embryo development. Timing parameters were categorized into four quartiles. The probability of an embryo developing to a blastocyst was linked to a strict chronology of development. To further evaluate…
Clinical experience and perinatal outcome of blastocyst transfer after coculture of human embryos with human endometrial epithelial cells: a 5-year f…
2003
Abstract Objective To evaluate the reproductive and neonatal outcome of blastocyst transfer after coculture with human endometrial epithelial cells in IVF and oocyte donation. Design Retrospective study. Setting Private assisted reproductive center. Patient(s) Two hundred sixty women undergoing IVF and 469 oocyte recipients. Intervention(s) IVF or intracytoplasmic sperm injection (ICSI) and transfer of at least one blastocyst after coculture with human endometrial epithelial cells. Main outcome measure(s) Blastocyst formation rate, implantation and pregnancy rates, neonatal outcome, and congenital birth defects. Results Among patients who had transfer with their own oocytes, 1,193 of 2,349 …
Clinical validation of embryo culture and selection by morphokinetic analysis: a randomized, controlled trial of the EmbryoScope.
2014
Objective To determine whether incubation in the integrated EmbryoScope time-lapse monitoring system (TMS) and selection supported by the use of a multivariable morphokinetic model improve reproductive outcomes in comparison with incubation in a standard incubator (SI) embryo culture and selection based exclusively on morphology. Design Prospective, randomized, double-blinded, controlled study. Setting University-affiliated private in vitro fertilization (IVF) clinic. Patient(s) Eight hundred forty-three infertile couples undergoing intracytoplasmic sperm injection (ICSI). Intervention(s) No patient intervention; embryos cultured in SI with development evaluated only by morphology (control …
Improved accuracy of hysteroembryoscopic biopsies for karyotyping early missed abortions
2003
Abstract Objective To assess the potential of direct embryo and chorion biopsies obtained by hysteroembryoscopy for karyotyping early missed abortions. Design Clinical prospective descriptive study. Setting Instituto Valenciano de Infertilidad, Valencia, Spain. Patient(s) Sixty-eight women (71 gestational sacs) with missed abortions. The gestational age on ultrasound was 6.3 weeks (range, 4–10 weeks). Intervention(s) Transcervical hysteroembryoscopy before curettage. Main outcome measure(s) Comparison between the cytogenetic results from hysteroembryoscopic biospies and those of the curettage material. Result(s) Hysteroembryoscopic biopsies could be taken in 97.2% of the gestational sacs. D…
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…
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…
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…
Characterization of the interaction of the antifungal and cytotoxic cyclic glycolipopeptide hassallidin with sterol-containing lipid membranes.
2019
Hassallidins are cyclic glycolipopeptides produced by cyanobacteria and other prokaryotes. The hassallidin structure consists of a peptide ring of eight amino acids where a fatty acid chain, additional amino acids, and sugar moieties are attached. Hassallidins show antifungal activity against several opportunistic human pathogenic fungi, but does not harbor antibacterial effects. However, they have not been studied on mammalian cells, and the mechanism of action is unknown. We purified hassallidin D from cultured cyanobacterium Anabaena sp. UHCC 0258 and characterized its effect on mammalian and fungal cells. Ultrastructural analysis showed that hassallidin D disrupts cell membranes, causin…
Amyloid-β toxicity and tau hyperphosphorylation are linked via RCAN1 in Alzheimer's disease.
2011
Amyloid-β peptide (Aβ) toxicity and tau hyperphosphorylation are hallmarks of Alzheimer’s disease (AD). How their molecular relationships may affect the etiology, progression, and severity of the disease, however, has not been elucidated. We now report that incubation of foetal rat cortical neurons with Aβ up-regulates expression of the Regulator of Calcineurin gene RCAN1, and this is mediated by Aβ-induced oxidative stress. Calcineurin (PPP3CA) is a serine-threonine phosphatase that dephosphorylates tau. RCAN1 proteins inhibit this phosphatase activity of calcineurin. Increased expression of RCAN1 also causes up-regulation of glycogen synthase kinase-3beta (GSK3β), a tau kinase. Thus, incr…