Search results for "Blastocyst"
showing 10 items of 137 documents
Embryo effects in human implantation: embryonic regulation of endometrial molecules in human implantation.
2001
: Embryonic implantation requires coordinated development of the blastocyst and the maternal endometrium. Considerable advances have been made in the understanding of the cell biology of human embryo and maternal endometrium as separate entities. Nevertheless, communication between them and their reciprocal effects on each other constitute an exciting and as-yet unsolved problem in reproductive medicine. Cross-talk among the embryo, endometrium, and the corpus luteum are known to occur in ruminants and primates; more specifically, endometrial-embryonic interactions have been reported in rodents and primates. Here, we present updated information in humans on the embryonic regulation of endom…
Dithiothreitol prevents age-associated decrease in oocyte/conceptus viability in vitro.
1998
The present study was designed to ascertain whether the negative effects on reproductive potential of post-ovulatory ageing in vitro of oocytes can be prevented by antioxidant therapy. Mouse metaphase II (MII) oocytes were aged in vitro for 12 h prior to insemination in the presence of varying concentrations of L-ascorbic acid, 6-methoxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), L-cystine dihydrochloride, ethylenediaminetetraacetic acid (EDTA), beta-mercaptoethanol and DL-dithiothreitol (DTT). In-vitro ageing of oocytes was associated with lower fertilization rate, higher proportion of concepti exhibiting cellular fragmentation at 24 h post-insemination and lower percentage of…
Human endometrial CD98 is essential for blastocyst adhesion.
2010
Background Understanding the molecular basis of embryonic implantation is of great clinical and biological relevance. Little is currently known about the adhesion receptors that determine endometrial receptivity for embryonic implantation in humans. Methods and Principal Findings Using two human endometrial cell lines characterized by low and high receptivity, we identified the membrane receptor CD98 as a novel molecule selectively and significantly associated with the receptive phenotype. In human endometrial samples, CD98 was the only molecule studied whose expression was restricted to the implantation window in human endometrial tissue. CD98 expression was restricted to the apical surfac…
Blastocyst formation is similar in obese and normal weight women: a morphokinetic study
2021
Abstract STUDY QUESTION Does the embryo cleavage pattern and rate of blastocyst formation differ between normal weight and obese women undergoing IVF? SUMMARY ANSWER Embryo morphokinetic development, final blastocyst formation rate and blastocyst morphology do not differ between obese and normal weight women. WHAT IS KNOWN ALREADY Female obesity has been related to impaired IVF outcomes. Although the mechanisms responsible for this detrimental effect are thought to include impaired oocyte and embryo quality and reduced endometrial receptivity, they are yet to be confirmed. Embryo quality has been commonly assessed using static morphological criteria. Only three studies have analysed the pro…
Beneficial Effect of Melatonin on Blastocyst In Vitro Production from Heat-Stressed Bovine Oocytes
2013
Melatonin may play an important role in protecting gametes and embryos from the potential harmful effects of oxidative stress. In this study, we first examined two different heat stress (HS) treatments for in vitro oocyte maturation (Experiment 1: 38.5 vs 41.0°C, during the first 20 h; Experiment 2: 38.5 vs 41.5°C, during the entire period) on bovine oocyte maturation and embryo development. Second, we tested different melatonin concentrations added to the maturation and culture medium (Experiment 3: 0, 10(-12) , 10(-9) , 10(-4) m; Experiment 4: 0, 10(-3) m), both with and without HS (38.5 or 41.5°C, respectively). In Experiment 1, the HS treatment resulted in a lower maturation rate and …
Vitrification of zona-free rabbit expanded or hatching blastocysts: a possible model for human blastocysts.
2003
BACKGROUND: The purpose of this study was to test the effectiveness of one two-step (A) and two one-step (B1 and B2) vitrification procedures on denuded expanded or hatching rabbit blastocysts held in standard sealed plastic straws as a possible model for human blastocysts. The effect of blastocyst size was also studied on the basis of three size categories (I: diameter <200 μm; II: diameter 200-299 μm; III: diameter ≥300 μm). METHODS: Rabbit expanded or hatching blastocysts were vitrified at day 4 or 5. Before vitrification, the zona pellucida was removed using acidic phosphate buffered saline. For the two-step procedure, prior to vitrification, blastocysts were pre-equilibrated in a solut…
Human Endometrial Mucin MUC1 Is Up-Regulated by Progesterone and Down-Regulated In Vitro by the Human Blastocyst1
2001
Expression of MUC1 in endometrial epithelium has been suggested to create a barrier to embryo attachment that must be lifted at the time of implantation. In this study, we investigated the hormonal regulation of human endometrial MUC1 in hormone replacement therapy cycles and in the human blastocyst. We also analyzed the embryonic regulation of MUC1 in human endometrial epithelial cells (EECs) during the apposition and adhesion phases of human implantation using two different in vitro models. Our results indicate that endometrial MUC1 mRNA and immunoreactive protein increase in receptive endometrium compared to nonreceptive endometrium. Human blastocysts express MUC1, as demonstrated by rev…
Leptin and Leptin Receptor Are Expressed in the Human Endometrium and Endometrial Leptin Secretion Is Regulated by the Human Blastocyst1
2000
Embryonic implantation is a crucial event for the human reproductive function. Cytokines and paracrine molecules have been proposed as putative local regulators of this process. The leptin or the OB protein has been linked to the reproductive function and inflammatory response. In the present study, we describe for the first time the expression of leptin and leptin receptor (long form) in the secretory endometrium and that endometrial leptin secretion is regulated in vitro by the human blastocyst. Leptin and leptin receptor messenger RNA and protein were identified in secretory endometrium and in cultured endometrial epithelial cells (EECs) by RT-PCR, Western blot, and immunohistochemistry.…
The Human Blastocyst Regulates Endometrial Epithelial Apoptosis in Embryonic Adhesion1
2000
The implanting blastocyst must appose and adhere to the endometrial epithelium and, subsequently, invade it. Locally regulated uterine epithelial apoptosis induced by the embryo is a crucial step of the epithelial invasion in rodents. To address the physiological relevance of this process in humans, we investigated the effect of single human blastocysts on the regulation of apoptosis in cultured human endometrial epithelial cells (hEEC) in both apposition and adhesion phases of implantation. Here, we report a co-ordinated embryonic regulation of hEEC apoptosis. In the apposition phase, the presence of a blastocyst rescues hEEC from the apoptotic pathway. However, when the human blastocyst a…
Embryonic adhesion is not affected by endometrial leptin receptor gene silencing.
2006
Objective In rodents, evidence suggests that the leptin system is mandatory for embryonic implantation. We aimed to investigate the functional relevance of the endometrial leptin receptor (OB-R) in the adhesion phase of human implantation. Design We used an in vitro model for embryonic adhesion, composed of a human endometrial cell line (HEC1-A) and B6C3F1 mouse embryos. The OB-R gene was silenced in a stable manner by RNA interference, and embryonic adhesion rates were analyzed. Setting Research laboratory at a university-affiliated center. Intervention(s) RNA interference. Main Outcome Measure(s) Embryonic adhesion in cells treated with OB-R RNAi. Result(s) The OB-R shRNA-transfected cell…