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PubMed2000

Effects of the porcine oviduct-specific glycoprotein on fertilization, polyspermy, and embryonic development in vitro.

This study evaluated the effects of porcine oviduct-specific glycoprotein (pOSP) on in vitro fertilization (IVF), polyspermy, and development to blastocyst. Experiment 1 evaluated the effects of various concentrations (0-100 microgram/ml) of purified pOSP on fertilization parameters, including penetration, polyspermy, male pronuclear formation, and mean number of sperm penetrated per oocyte. Experiment 2 examined the ability of an anti-pOSP immunoglobulin G to inhibit the observed effects of pOSP on fertilization parameters. Experiments 3 and 4 examined various concentrations of pOSP (0-100 microgram/ml) on zona pellucida solubility and sperm binding, respectively. Lastly, experiment 5 assessed the effects of various concentrations of pOSP (0-100 microgram/ml) on the in vitro embryo cleavage rate and development to blastocyst. Pig oocytes matured and fertilized in vitro were used for all experiments. An effect of treatment (P < 0.05) was detected for pOSP on penetration, polyspermy, and mean number of sperm per oocyte. Concentrations for pOSP of 0-50 microgram/ml had no effect on sperm penetration rates; however, compared with the control, 100 microgram/ml significantly decreased the penetration rate (74% vs. 41%). Addition of 10-100 microgram/ml significantly reduced the polyspermy rate compared with the control (61% vs. 24-29%). The decrease in polyspermy achieved by addition of pOSP during preincubation and IVF was blocked with a specific antibody to pOSP. No effect of treatment was observed on zona digestion time relative to the control; however, the number of sperm bound to the zona pellucida was significantly decreased by treatment (P < 0.05). Compared with the control, all concentrations of pOSP examined reduced the number of sperm bound per oocyte (45 vs. 19-34). A treatment effect (P < 0.05) was observed for pOSP on embryo development to blastocyst but not on cleavage rates. Addition of pOSP during preincubation and fertilization significantly increased postcleavage development to blastocyst, but a synergistic stimulation on development was not detected when pOSP was included during in vitro culture. These results indicate that exposure to pOSP before and during fertilization reduces the incidence of polyspermy in pig oocytes, reduces the number of bound sperm, and increases postcleavage development to blastocyst.

Animals↗
PubMed2000

Microgravity and hypergravity effects on fertilization of the salamander Pleurodeles waltl (urodele amphibian).

Effects of microgravity (microG) on fertilization were studied in the urodele amphibian Pleurodeles waltl on board the MIR space station. Genetic and cytomorphologic analyses ruled out parthenogenesis or gynogenesis and proved that fertilization did occur in microG. Actual fertilization was demonstrated by the analysis of the distribution of peptidase-1 genes, a polymorphic sex-linked enzyme, in progenies obtained in microG. Further evidence of fertilization was provided by the presence of spermatozoa in the perivitelline space and in the fertilization layer of the microG eggs and by the presence of a female pronucleus and male pronuclei in the egg cytoplasm. Experiments in microG and in 1.4G, 2G, and 3G hypergravity showed for the first time that, compared to eggs in 1G, several characteristics of the fertilization process including the cortical reaction and the microvillus transformations were altered depending on the gravitational force applied to the eggs. Microvillus elevation, the most evident feature, was reduced on microG-eggs and amplified on eggs submitted to 2G and 3G. No lethal consequences of these alterations on the early development of microG-eggs were observed.

Animals↗
PubMed2001

Fertilization of sea urchin eggs and sperm motility are negatively impacted under low hypergravitational forces significant to space flight.

Sperm and other flagellates swim faster in microgravity (microG) than in 1 G, raising the question of whether fertilization is altered under conditions of space travel. Such alterations have implications for reproduction of plant and animal food and for long-term space habitation by man. We previously demonstrated that microG accelerates protein phosphorylation during initiation of sperm motility but delays the sperm response to the egg chemotactic factor, speract. Thus sperm are sensitive to changes in gravitational force. New experiments using the NiZeMi centrifugal microscope examined whether low hypergravity (hyperG) causes effects opposite to microG on sperm motility, signal transduction, and fertilization. Sperm % motility and straight-line velocity were significantly inhibited by as little as 1.3 G. The phosphorylation states of FP130, an axonemal phosphoprotein, and FP160, a cAMP-dependent salt-extractable flagellar protein, both coupled to motility activation, showed a more rapid decline in hyperG. Most critically, hyperG caused an approximately 50% reduction in both the rate of sperm-egg binding and fertilization. The similar extent of inhibition of both fertilization parameters in hyperG suggests that the primary effect is on sperm rather than eggs. These results not only support our earlier microG data demonstrating that sperm are sensitive to small changes in gravitational forces but more importantly now show that this sensitivity affects the ability of sperm to fertilize eggs. Thus, more detailed studies on the impact of space flight on development should include studies of sperm function and fertilization.

Animals↗
PubMed2005

Fibroids and in-vitro fertilization: which comes first?

PURPOSE OF REVIEW: There is no consensus about the impact of uterine fibroids on fertility. This review explores past and recent studies that investigated the effects of submucosal, intramural, and subserosal fibroids on in-vitro fertilization (IVF) outcomes. We discuss the importance of proper evaluation of the uterus and endometrial cavity, and current options for optimal fibroid management in patients desiring fertility. RECENT FINDINGS: Several studies have reviewed the data on fibroids and infertility, further exploring this potential relationship. Two recent studies investigated reproductive outcomes before and after myomectomy, and IVF outcomes based on fibroid size and location. Both studies concluded that fibroids can impair reproductive outcomes. Several papers thoroughly reviewed medical and surgical management options for patients with fibroids and desired fertility. Although several medical therapies may reduce fibroid volume or decrease menorrhagia, myomectomy remains the standard of care for future fertility. Recent data identified an increased rate of pregnancy complications after uterine artery embolization compared with laparoscopic myomectomy. A new procedure, magnetic resonance imaging-guided focused ultrasound ablation, shows promise for the management of symptomatic fibroids, and possibly for the management of fibroids prior to pregnancy. As with embolization, more data are needed to evaluate postprocedure fertility and pregnancy outcomes. SUMMARY: Fibroid location, followed by size, is the most important factor determining the impact of fibroids on IVF outcomes. Any distortion of the endometrial cavity seriously affects IVF outcomes, and myomectomy is indicated in this situation. Myomectomy should also be considered for patients with large fibroids, and for patients with unexplained unsuccessful IVF cycles.

Female↗
PubMed1998

Natural selection on age-specific fertilities in human females: comparison of individual-level fitness measures.

Lifetime reproductive success and timing of reproduction are key components of life-history evolution. To understand the evolution of reproductive schedules, it is important to use a measure of fitness that is sensitive both to reproductive quantity and reproductive timing. There is a contradiction between the theory, which mainly focuses on the rate measures of fitness (r and lambda), and empirical studies, which mainly use lifetime reproductive success (LRS), or some of its correlates, as a fitness measure. We measured phenotypic selection on age-specific fertilities in three pre-modern human populations using individually estimated finite rate of increase, er (lambda). We found that lambda and lifetime reproductive success ranked individuals differently according to their fitness: for example, a female giving birth to four children at a young age may actually have a higher fitness than a female giving birth to six children at a greater age. Increase in fertility at the young age classes (15-19 years) was favoured by selection, but the intensity of selection on fertility was higher in the older age classes (20-30 years), where the variance in fertility was highest. Hence, variation in fertility in the older age classes (20-30) was actually responsible for most of the observed variation in fitness among the individuals. Additionally, more than 90% of variation in fitness (lambda) was attributable to individual differences in LRS, whereas only about 5% of all variation in fitness was due to differences in the reproductive schedule. The rate-sensitive fitness measure did not significantly challenge the importance of total fertility as a component of fitness in humans. However, the rate-sensitive measure clearly allowed more accurate estimation of individual fitness, which may be important for answering some more specific questions.

Adaptation, Physiological↗
PubMed2004

Effect of interactions on the nutrient status of a tropical soil treated with green manures and inorganic phosphate fertilizers.

Integrated nutrient management systems using plant residues and inorganic P fertilizers have high potential for increasing crop production and ensuring sustainability in the tropics, but their adoption requires in-depth understanding of nutrient dynamics in such systems. This was examined in a highly weathered tropical soil treated with green manures (GMs) and P fertilizers in two experiments conducted in the laboratory and glasshouse. The treatments were factorial combinations of the GMs (Calopogonium caeruleum, Gliricidia sepium, and Imperata cylindrica) and P fertilizers (phosphate rocks [PRs] from North Carolina, China, and Algeria, and triple superphosphate) replicated thrice. Olsen P, mineral N, pH, and exchangeable K, Ca, and Mg were monitored in a laboratory incubation study for 16 months. The change in soil P fractions and available P was also determined at the end of the study. Phosphorus available from the amendments was quantified at monthly intervals for 5 months by 33P-32P double isotopic labeling in the glasshouse using Setaria sphacelata as test crop. The GMs were labeled with 33P to determine their contribution to P taken up by Setaria, while that from the P fertilizers was indirectly measured by labeling the soil with 32P. The P fertilizers hardly changed Olsen P and exchangeable cations during 16 months of incubation. The legume GMs and legume GM+P did not change Olsen P, lowered exchangeable Ca, and increased exchangeable K about threefold (4.5 cmol[+]kg(-1) soil) in the first 4 months, even as large amounts of NH4-N accumulated (approximately 1000 mg kg soil(-1)) and soil pH increased to more than 6.5. Afterwards, Olsen P and exchangeable Ca and Mg increased (threefold) as NH4+-N and soil pH declined. The legume GMs also augmented reversibly sorbed P in Al-P and Fe-P fractions resulting in high residual effect in the soil, while fertilizer-P was irreversibly retained. The GMs increased PR-P utilization by 40 to over 80%, mobilized soil P, and markedly enhanced uptake of N, K, Ca, and Mg. Thus GMs+PRs is an appropriate combination for correcting nutrient deficiencies in tropical soils.

Agriculture↗
PubMed2001

Fertilization selection on egg and jelly-coat size in the sand dollar Dendraster excentricus.

Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm-egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a selection experiment. We used a cross-sectional analysis of correlated characters to estimate the selection gradients on egg and jelly-coat size in five replicate male pairs of the sand dollar Dendraster excentricus. Results indicated that eggs with larger cells and jelly coats were preferentially fertilized under sperm limitation in the laboratory. The selection gradients were an average of 922% steeper for egg than for jelly-coat size. The standardized selection gradients for egg and jelly-coat size were similar. Our results suggest that fertilization selection can act on both egg-cell and jelly-coat size but that an increase in egg-cell volume is much more likely to increase fertilization success than an equal change in jelly-coat volume. The strengths of the selection gradients were inversely related to the correlation of egg traits across replicate egg clutches. This result suggests the importance of replication in studies of selection of correlated characters.

Animals↗
PubMed1985

Prognostic value of the heterologous ovum penetration test for human in vitro fertilization.

In order to evaluate the prognostic value of the heterologous ovum penetration test (HOP-test) the results of this test were compared with the fertilization rate of human ova in a programme for in vitro fertilization and embryo transfer (IVF/ET). Sperm from 29 husbands (23 normozoospermic and 6 with an abnormal semen profile) were exposed on one occasion to approximately 30 hamster ova in the HOP-test and on 1 to 3 occasions to 1 to 4 preovulatory oocytes obtained from the respective wives. The mean penetration rate (+/- SEM) of the hamster ova was 43 +/- 4% (range: 0-62%) for the normozoospermic men, and 23 +/- 6% (range: 0-47%) for the men with abnormal semen profiles. In 20 out of 23 couples in which the husbands were normozoospermic, sperm penetrated the hamster ova as well as they fertilized human ova; however, in one couple, a false-positive result was obtained (penetration of the hamster ova and no fertilization of the human oocytes) and in one couple a false-negative result occurred. One negative IVF result was correctly predicted by the HOP-test. In the 6 patients with disturbed sperm motility no correct positive or negative results were obtained, whilst 4 false-positive and 2 false-negative results occurred using the HOP-test. Although the number of patients with disturbed sperm motility was small, the data suggest that the HOP-test is of limited value in predicting fertility in an IVF program for couples with reduced fertility.

Adult↗
PubMed1991

Effects of piperine on hamster sperm capacitation and fertilization in vitro.

The effect of piperine on the fertilizing ability of hamster sperm was investigated in vitro. Sperm were incubated in a capacitation medium for 3 h prior to co-incubation with hamster eggs in a fertilization medium for another 3 h. Addition of 0.18-1.05 mM piperine to the capacitation medium reduced both the percentage of eggs fertilized and the degree of polyspermia in a dose-dependent manner. When piperine was added to the fertilization medium alone, a significant reduction in fertilization was observed only at high doses (0.70-1.05 mM). The presence of piperine in the capacitation medium inhibited the acrosome reaction in a dose-dependent manner but had no effect on sperm motility, whether this was measured quantitatively or qualitatively. Piperine also inhibited the influx of calcium into sperm during capacitation. It is suggested that such an inhibition might be a major cause of a reduction of the acrosome reaction and the subsequent impairment of fertilizing ability of sperm.

Acrosome↗
PubMed2006

Differences in fertility by HIV serostatus and adjusted HIV prevalence data from an antenatal clinic in northern Uganda.

OBJECTIVES: To estimate differences in fertility by HIV serostatus and to validate an adjustment method for estimating the HIV prevalence in the general female population using data from an antenatal clinic. METHODS: We used Cox regression models to retrospectively estimate the age-specific relative fertility (RF) of HIV-positive compared to HIV-negative women among 3314 antenatal clinic attenders in northern Uganda. RF and the age distribution of women in the general female population were used to extrapolate the antenatal clinic-based HIV prevalence. This procedure was indirectly validated by comparing the adjusted estimate with those based on standard adjustment factors derived from general female populations in Uganda and Tanzania. RESULTS: HIV-positive women reported a lower fertility than HIV-negative women [age-adjusted RF=0.83, 95% confidence interval (CI): 0.75-0.93]. Except for girls aged 15-19 (RF=0.96, 95% CI: 0.74-1.24) HIV-positive women in all age groups were less fertile (20-24 year: RF=0.83, 95% CI: 0.67-1.01; 25-29 years: RF=0.79, 95% CI: 0.62-1.00; 30-49 year: RF=0.79, 95% CI: 0.65-0.96]. Adjusting the antenatal clinic-based HIV prevalence (11.6%) for these differences yields a higher estimate (13.8%) that is lower than those based on standard adjustment factors derived from general female populations (from 14.6% to 17.7%). CONCLUSIONS: The age-specific pattern of differential fertility by HIV serostatus derived from antenatal clinic data is consistent with findings from population-based studies conducted in Africa. However, differences in fertility between HIV positive and HIV-negative clients underestimate those in the general female population yielding inaccurate estimates when used to extrapolate the HIV prevalence.

Adolescent↗
PubMedDate not supplied

Seminal plasma beta-human chorionic gonadotropin (beta-HCG): relationships with seminal characteristics and spermatozoal fertilizing capacity.

Seminal plasma beta-human chorionic gonadotropin (beta-HCG) levels were determined in 254 semen samples collected from fertile and suspected subfertile men, and their relationships with seminal characteristics and spermatozoal fertilizing capacity were evaluated. Radioimmunoassayable beta-HCG, as defined by greater than 5 mIU/ml concentration, was demonstrated in only 44.5% of all the samples studied. beta-HCG concentrations were similar in normospermic, oligospermic and azoospermic samples. There were no significant differences in beta-HCG concentration between high-motility and low-motility samples, between normal-morphology and abnormal-morphology samples, and between high-fertilizing capacity and low-fertilizing capacity samples. No significant correlations between the concentrations of beta-HCG and individual parameters of semen analysis and spermatozoal fertilizing capacity among the various groups of samples were observed. The physiological role of seminal plasma beta-HCG is presently uncertain and the relationship of its determination to male fertility requires further investigation.

Chorionic Gonadotropin↗
PubMedDate not supplied

Spermatozoal fertilizing capacity in polyzoospermia: a preliminary study.

Men with the spermatological symptom of polyzoospermia (greater than 250 X 10(6) sperm/ml) have been reported to seldom impregnate their wives. It was the aim of this study to investigate the spermatozoal fertilizing capacity in polyzoospermia by the human sperm and zona-free hamster ova penetration bioassay. General semen characteristics and in vitro spermatozoal fertilizing capacity were studied in 12 polyzoospermic male partners of couples of infertile marriages. The results were compared with those from a control group of normospermic fertile men (n = 22). No significant differences in sperm motility, normal morphology and in vitro spermatozoal fertilizing capacity were found between the two groups. The polyzoospermic men we studied did not appear to have any defect with the spermatozoal fertilizing capacity, as assessed by the heterologous sperm--ova penetration bioassay. The apparent impairment of fertility and higher abortion rate in couples with polyzoospermic male partners, as described in the literature, may be related to chromosomal aberrations and/or other unknown functional defect of the spermatozoa.

Animals↗
PubMedDate not supplied

Fertilization failure and dysfunctions as possible causes for human idiopathic infertility.

Consideration of the most common currently practiced laboratory assays for human spermatozoal fertility are discussed, with reference to the relevance of such assays to success or failure in human in vitro fertilization (IVF). Such IVF therapy should be the definitive challenge for human spermatozoal fertilization ability. However, when fertilization fails, is polyspermic, or is suboptimal, then questions concerning the step or steps in the process of fertilization which are dysfunctional remain unanswered. Quite possibly new assays need to be devised to address these problems, while in the meantime our present laboratory assay systems need to be improved to discern those defects in fertilization which operate in many cases of human idiopathic infertility.

Animals↗
PubMedDate not supplied

Acrosin activity in pelleted frozen sperm does not correlate with in vitro fertilization of oocytes.

Spermatozoa pelleted after swim-up were frozen and then analysed in batches for acrosin activity, using a spectrophotometric method, and expressed as microIU micrograms DNA-1. A total of 259 sperm samples were analysed and the acrosin activity compared with fertilization in vitro. Of these, 224 samples fertilized at least one oocyte and 35 samples failed to fertilize any oocyte. Analysis by Student's t-test indicated that there was a statistically significant difference (P = 0.02) in acrosin activity between the two groups. However, when samples that failed to fertilize were matched for concentration, motility and normal morphology with samples that fertilized, this significance was lost (P = 0.77). It is concluded that total acrosin in pelleted sperm frozen after regular swim-up, does not correlate with fertilizing ability of spermatozoa used for insemination.

Acrosin↗
PubMed2004

Relationship between protamine deficiency with fertilization rate and incidence of sperm premature chromosomal condensation post-ICSI.

After aneuploidy, sperm premature chromatin condensation (PCC) is the next prevalent cause of fertilization failure. Therefore the aim of this study was to evaluate the effect of sperm protamine deficiency on sperm PCC formation post-ICSI. Chromatin analysis was carried out on failed fertilized oocytes post-ICSI and incidences of sperm PCC were evaluated and the results were compared with the extent of protamine deficiency assessed by chromomycin A3. The results show that incidence of sperm PCC was significantly different in failed fertilized oocytes injected from semen samples with greater or less than 30% CMA3 positivity (P = 0.04). However, except for fertilization rate (P < 0.001), the mean number of MII, MI and germinal vesicles oocytes and percentage normal sperm were not significantly different between the two groups (P > 0.05). A significant correlation was observed between sperm protamine deficiency with fertilization rate. Hence sperm protamine deficiency affects fertilization rate and possibly prones sperm to PCC post-ICSI.

Adult↗
PubMed2005

Inhibition of the acrosome reaction (AR) and fertilization capacity of mouse spermatozoa by norethisterone A-ring reduced metabolite (5alpha-NET).

The contra gestational effects of norethisterone and its main metabolites, 5alpha-NET and 3beta5alpha-NET, has been demonstrated in several species. However, the focus has been mainly on their effects in the uterus. We previously reported that 5alpha-NET inhibits the progesterone-induced AR in pig spermatozoa and induces severe morphological damage to fertilized mouse oocytes. In the present study, we analysed the effects of these compounds on the fertilization process in vitro. Oocytes and spermatozoa were obtained from Balb/c female and C57BL/6J male mice, respectively. Both, the AR assays and the fertilization experiments were performed under different steroid treatment schemes using progesterone as a control. Results showed that norethisterone induced the AR, while 5alpha-NET reduced the percentage of spermatozoa that had undergone progesterone-induced AR. Both 17beta-estradiol and 3beta5alpha-NET induced the AR in a considerably lower percentage of spermatozoa than progesterone. In addition, when 5alpha-NET was added to the medium simultaneously with progesterone at the moment of fertilization, the percentage of fertilized oocytes (two-cell stage) decreased by as much as 77% as compared with the control progesterone-treated group. All results suggest that these compounds can have important effects on the fertilization process.

Acrosome Reaction↗
PubMed1993

Return of fertility after the removal of intrauterine devices: a comparison of inert and copper bearing devices.

The use of intrauterine device (IUD) has been suspected to be linked to involuntary infertility due to increased risk of pelvic inflammatory diseases. Nevertheless, it remains unclear whether the overall risk of infertility after discontinuing use of IUD increases with the duration of IUD use. Thus, the present study was designed to evaluate the return of fertility after discontinuing use of copper containing IUDs compared to inert IUD and to determine a possible relationship between the length of IUD use and return of fertility. Ninety women with Lippes Loop type D (LL), 88 women with Copper-T200 (TCu-200) and 83 women with Multiload Copper-250 (MLCu-250) were included in the analysis. The life table analysis and log rank-test showed that TCu-200 and MLCu-250 acceptors had a more rapid return of fertility compared to LL acceptors, although there was no significant difference in the return of fertility between TCu-200 and MLCu-250 acceptors. Compared to LL acceptors, the net cumulative probability of pregnancy after discontinuing use of IUD was 3 times higher in copper containing IUD acceptors in the first 3 months and somewhat higher in the first 4 to 11 months after removal of IUD. The length of use in copper containing IUDs (TCu-200 and MLCu-250) acceptors did not influence the return of fertility, whereas the return of fertility after removal of inert IUD (LL) was significantly higher in case of the use for shorter than 48 months compared to the use for longer than 48 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2005

Headaches in women undergoing in vitro fertilization and embryo-transfer treatment.

BACKGROUND: In vitro fertilization and embryo transfer has become a common therapeutic modality in modern fertility medicines. Treatment protocols are associated with exaggerated hormonal fluctuations in order to promote multiple follicular development and support of embryo survival. Estrogen is considered to be closely linked to migraine, and its extreme serum level fluctuations have been considered to trigger migrainous headaches. OBJECTIVE: To assess the prevalence, nature, and timing of headache attacks during the course of in vitro fertilization and embryo-transfer treatments. METHODS: We retrospectively evaluated the prevalence and the characteristics of headache among 98 women undergoing in vitro fertilization and embryo transfer therapy using a structured telephone interview. RESULTS: Out of the 98 evaluated patients 25 were migraine sufferers. Headache attacks during the in vitro fertilization and embryo transfer protocol were reported by 28.6% (n = 28) of the women and were significantly more prevalent among the migraineurs. The attacks were of debilitating severity in 82% (n = 23) of patients who reported headaches during treatment. Headache occurred most frequently following gonadotropin-releasing hormone (GnRH) analog induced hypothalamic-pituitary-ovarian axis downregulation, typically associated with very low 17-beta-estradiol (17-beta-E2) serum level. CONCLUSIONS: In vitro fertilization and embryo-transfer treatment might be associated with various degrees of headache. This is mostly observed in patients with migraine headache background and specifically during the downregulation stage of treatment, when very low levels of 17-beta-E2 are observed. (Headache 2005;45:215-219).

Embryo Transfer↗