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Fertilization Failure (fertilization + failure)

Distribution by Scientific Domains
Medical Sciences83%

Selected Abstracts

Effects of tumour necrosis factor alpha and interleukin-6 on progesterone and calcium ionophore-induced acrosome reaction

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 3 2009
F. Lampiao
Summary For human spermatozoa to successfully fertilize the oocyte, they need to undergo a timely acrosome reaction (AR). Factors which disturb the AR may lead to fertilization failure. The objective of this study was to investigate the effects of two cytokines namely tumour necrosis factor alpha (TNF-,) and interleukin-6 (IL-6) on the spontaneous, calcium ionophore-induced and progesterone-induced human sperm AR. Twenty-two normal semen samples were treated with increasing concentrations of TNF-, and IL-6 after spermatozoa were isolated by a double wash swim-up method. The AR was induced by calcium ionophore A23187 and progesterone. The AR was determined by using fluorescein isothiacyanate Pisum sativum agglutinin and observed under fluorescence microscope. Both TNF-, and IL-6 could decrease the spontaneous, ionophore and progesterone-induced AR (p < 0.05) in a dose-dependent manner. TNF-, showed a more potent inhibiting effect than IL-6 by inhibiting the AR at lower concentrations. This study has demonstrated that TNF-, and IL-6 play a role in inhibiting both the non-physiological as well as physiologically elicited AR by calcium ionophore and progesterone respectively. [source]

ORIGINAL ARTICLE: TH1 , TH2 Response and the Atopy Risk in Patients with Reproduction Failure

AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2009
Jana Hanzlikova
Problem, Enhanced TH2 activity is characteristic for atopic diseases and is observed also in physiological pregnancy. The immune causes of repeated pregnancy losses and/or repeated in vitro fertilization failure may be associated with TH2 hypoactivity. The association with frequency of atopic diseases is unclear. Method of Study, Intracellular production of IL-4 and IFN-, by peripheral CD4+ T lymphocytes was studied, as well as serum levels of total and allergen specific IgE. Simultaneously skin prick tests with inhalant allergens were performed, and clinical features of atopy were registered by means of a questionnaire. Results, Lower intracellular production of IL-4 by peripheral CD4+ T cells and lower frequency of elevated total and allergen specific IgE were found in women with reproduction failure compared to controls, as well as lower frequency of some symptoms possibly associated with atopy. Conclusion, Our study showed the presence of TH2 hypoactivity in women with reproduction failure, which may be associated with lower occurrence of atopic diseases. [source]

Defective sperm decondensation: a cause for fertilization failure

ANDROLOGIA, Issue 1 2002
A. D. Esterhuizen
Summary. The study aimed to evaluate the role of chromatin packaging (CMA3 staining), sperm morphology during sperm-zona binding, sperm decondensation and the presence of polar bodies in oocytes that failed in vitro fertilization (IVF). The percentage CMA3 staining categorized the data into three groups, < 44%, n = 10; , 44,59%, n = 10; and ,60%, n = 29. Morphology groups were ,,4% (n = 11); > 4,14% (n = 19); and >14% (n = 19). One hundred and seventy-two oocytes that failed IVF were evaluated for sperm-zona binding, ooplasma penetration and sperm decondensation. Odds ratio analyses indicated that being in the ,60% CMA3 staining group resulted in a 15.6 fold increase in the risk of decondensation failure, relative to CMA3 staining of <44%. For morphology, there was a 2.17 fold decrease in the risk of fertilization failure in the morphology group with >4,14% normal cells, while it increased 2.45 fold for the morphology group with ,4% normal cells. Using CMA3 fluorescence to discriminate, 51% of the oocytes in the group with elevated CMA3 fluorescence had no sperm in the ooplasma compared to 32% and 16% penetration failure in the CMA3 staining groups ,44,59% and <44%, respectively. Sperm chromatin packaging quality and sperm morphology assessments are useful clinical indicators of human fertilization failure. Immunofluorescence techniques could be used to provide a clear diagnosis of failed fertilization. [source]

Analysis of segregation distortion and association of the bovine FGF2 with fertilization rate and early embryonic survival

ANIMAL GENETICS, Issue 5 2009
X. Wang
Summary Fibroblast growth factor 2 (FGF2) plays an important role in fertility and early embryo development. The objectives of this study were to test the association of FGF2 polymorphisms with fertilization success in cattle using an in vitro fertilization experimental system and to investigate the mechanisms leading to the presence of rare alleles of FGF2 in the Holstein population. A total of 7502 fertilizations were performed and a total of 5049 embryos were produced to collect fertilization and embryo survival records. A total of 444 ovaries, from which oocytes were aspirated and fertilized, were genotyped for two single nucleotide polymorphisms (SNPs) previously identified in FGF2 (g.23G>T and g.11646A>G). Frequency of the TT genotype of the g.23G>T SNP was low in the ovary population (5.4%) and in a different Holstein cattle population (6.6%) examined in this study. Single SNP analysis showed that both SNPs were associated with early embryonic survival rate. Two-way interaction analysis revealed significant association of epistatic interaction between the SNPs with fertilization rate. To test whether or not low frequency of allele T for the g.23G>T SNP in the population is a result of a fertilization failure of T oocytes, semen from six GG bulls was used to fertilize a total of 458 oocytes obtained from 19 GT ovaries. A significant segregation distortion was observed for 169 embryos genotyped for the g.23G>T SNP. We conclude that oocytes carrying the T allele show a reduced fertilization rate and that segregation distortion leads to rarity of the TT genotype in the population. [source]