In-vitro fertilization (IVF) embryos are selected for transfer on the basis of morphology and rate of development. However, when a number of embryos have similar characteristics, the selection of the best embryos is left to chance. Recently, we proposed a simple, novel method to overcome this problem, based on pre-selection of embryos cleaving early to the two-cell stage. In this study we have adopted the same method to choose embryos fertilized after intracytoplasmic sperm injection (ICSI). Fertilized embryos that had cleaved to the two-cell stage by 27 h post-injection were designated as 'early cleavage' embryos, while those that had not yet reached the two-cell stage were designated as 'no early cleavage'. In all cases, the early cleavage embryos were transferred when available. Early cleavage was observed in 54 (61.4%) of the 88 cycles assessed. There were significantly (P = 0.04) more clinical pregnancies in the early cleavage group, 14/54 (25.9%), compared with the no early cleavage group 2/34 (3.2%). No differences between the groups were found when comparing key parameters (age, stimulation protocol and semen characteristics) of the couples. Using the ICSI technique, we have shown that early cleavage to the two-cell stage is not influenced by the timing of fertilization, and is more likely due to intrinsic factors within the oocyte or embryo that promote embryo cleavage after fertilization.
Leptin, the product of the ob gene, is a small peptide molecule synthesized by white adipocytes with an important role in the regulation of body fat and food intake. Leptin and leptin receptor mRNA were first detected in the brain and hypothalamus but now their ubiquitous presence has been demonstrated. Leptin receptor signal transduction involves the activation of signal transducer and activator of transcription (STAT)-3, a member of the transcription family of proteins. Leptin is regulated by hormones and cytokines, interleukin-1, tumour necrosis factor-alpha and transforming growth factor-beta, linking this molecule with the inflammatory response. In addition, emerging evidence has demonstrated that this molecule is related to reproductive function. This small protein is present in the ovary and decidua, in mature oocytes and during embryonic development and trophoblast invasion. Animal models have demonstrated that leptin-deficient ob/ob mice are sterile; however, fertility can be restored by exogenous leptin. In addition, embryos implanted in STAT-3-deficient mice degenerate rapidly and are the target disruption of STAT-3-provoked embryonic lethality. Leptin acts as a novel placental hormone participating in the control of fetal growth and development. Leptin could be a modulator for invasive features of cytotrophoblast cells. We postulate that leptin may have an autocrine/paracrine role in human implantation and placentation.
Background: Externalization of phosphatidylserine (EPS) occurs in apoptotic-like spermatozoa and could be used to remove them from sperm preparations to enhance sperm quality for assisted medical procreation. We first characterized EPS in sperms from infertile patients in terms of frequency of EPS spermatozoa as well as localization of phosphatidylserine (PS) on spermatozoa. Subsequently, we determined the impact of depleting EPS spermatozoa on sperm quality.
The aim of this study was to determine the effects of tumour necrosis factor alpha (TNF), interleukin-1 alpha (IL-1alpha), macrophage colony-stimulating factor (MCSF) and transforming growth factor beta (TGFbeta) on the secretion of matrix metalloproteinases (MMP), human chorionic gonadotrophin (HCG) and fetal fibronectin (fFN) by purified first trimester cytotrophoblastic cells (CTB) in vitro. CTB were obtained from legal abortions and cultured in vitro in the presence or absence of the different cytokines. Secreted gelatinases were analysed in the culture supernatants by zymography, by measurements of the total gelatinolytic activity and by enzyme immunoassays. HCG and fFN were measured by commercially available immunoassays. TNF increased the total gelatinolytic activity by increasing MMP-9 activity (P = 0.025-0.0177) but decreased MMP-2 activity (P < 0.03) and immunoreactivity (P < 0.05), fFN (P < 0.02) and HCG (P < 0.01). IL-1alpha significantly increased the secretion of fFN (P < 0.02), the activity (P < 0.02) and immunoreactivity (P < 0.05) of MMP-9 but had no effect on the other parameters. MCSF increased MMP-9 immunoreactivity (P < 0.05) and moderately decreased HCG. TGFbeta inhibited total gelatinolytic activity, MMP-9 activity and immunoreactivity, but was without effect on MMP-2 concentrations and activity. TGFbeta decreased HCG (P < 0.041) and increased fFN (P < 0.042). Our results indicate that TGFbeta, TNF and IL-1alpha are important regulators of trophoblastic MMP secretion.
The success of intracytoplasmic sperm injection (ICSI) warrants further study on the role of paternal factors in early human embryogenesis. To investigate whether poor sperm parameters can influence embryo development, we examined the development of ICSI-fertilized embryos to the blastocyst stage. We present results of blastocyst development from supernumerary ICSI embryos after co-culture on monkey kidney epithelial cells. In addition, we compare the development of supernumerary embryos to the blastocyst stage after ICSI and in-vitro fertilization (IVF). Of 168 supernumerary ICSI embryos, 45 (26.8%) developed to blastocysts. Sperm concentration and morphology did not influence blastocyst development. In contrast, blastocysts arose from spermatozoa that had a significantly higher (P = 0.015) forward progressive motility compared with spermatozoa from those patients who failed to produce blastocysts (42.7% versus 28.2%, respectively). Overall the rate of embryo development to the blastocyst stage after ICSI was lower (26.8%) than that after IVF (47.3%). When the rate of blastocyst development was calculated for patients with three or more supernumerary embryos, it remained significantly higher for the IVF patients than for the ICSI patients (45.6% versus 30.0%). There was no significant difference in the mean cell number and quality of the supernumerary embryos between the IVF and ICSI patients. This study confirms previous reports that have postulated that abnormal spermatozoa may manifest a negative paternal effect on preimplantation embryo development.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.