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PubMed2002

Effect of immunization of hamsters against recombinant P26h on fertility rates.

Despite the various contraceptive methods available, an effective and inexpensive method remains to be established. Immunocontraception may help to achieve this goal. P26h has been proposed as a candidate for the development of a male contraceptive vaccine. P26h, a hamster sperm protein, interacts with the zona pellucida. Furthermore, in vivo fertilization can be blocked completely by active immunization of male hamsters against P26h. Maltose binding protein (MBP)-P26 shares antigenic determinants with the native P26h present on cauda epididymal spermatozoa. The aim of the present study was to reproduce the immunocontraceptive properties of native P26h by immunizing male hamsters against a recombinant P26h fused with a maltose binding protein (MBP). Active immunization of male hamsters with the MBP-P26h showed that specific anti-P26h circulating IgGs could be generated. Mating of immunized male hamsters with superovulated females resulted in a significant decrease, 20-25%, in the fertilization rate. This result is in agreement with results from in vitro sperm-zona pellucida binding assays. Indeed, the anti-recombinant P26h IgGs showed lower inhibitory properties when compared with anti-native P26h IgG. Despite the high anti-P26h IgG titres generated in hamsters, histological studies showed that active immunization has no pathological sequelae to the reproductive tissues. The potential of P26h as a candidate for a contraceptive vaccine is discussed.

Alcohol Oxidoreductases↗
PubMed1990

Transient hyperprolactinemia during cycle stimulation and its influence on oocyte retrieval and fertilization rates.

Prolactin (PRL) has been shown to have inhibitory effect on follicle-stimulating hormone induced aromatase activity and estrogen biosynthesis in human granulosa cells cultured in vitro. To investigate the validity of the hypothesis that transient hyperprolactinemia during controlled ovarian hyperstimulation might influence follicular steroidogenesis and oocyte maturation, we measured serum PRL, estradiol, and progesterone before aspiration of oocytes in women undergoing ovarian stimulation (n = 108) in in vitro fertilization-embryo transfer. No correlation was detected between PRL and total number oocytes, number mature oocytes, fertilization rate, cleavage rate, and pregnancy rate. Transient elevation of PRL was a common finding in patients (57%) but was not associated with a poor clinical outcome.

Clomiphene↗
PubMed1995

Dieldrin modifies the hydrolysis of PIP2 and decreases the fertilization rate in Bufo arenarum oocytes.

Carbachol treatment in Bufo arenarum oocytes decreases the radioactivity in [32P]PIP2 in the following 20 min after stimulation and increases the [3H]glycerol labeling of 1,2-DAG at 1 min of stimulation. On the contrary, in Dieldrin treated oocytes carbachol stimulation produces an increase in [32P]PIP2 labeling without changes in [3H]1,2-DAG radioactivity. The sustained hydrolysis of PIP2 observed in Control oocytes is necessary to generate the intracellular second messengers which initiate the fertilization pathway. The lack of response to muscarinic stimulation in Dieldrin treated oocytes, may be associated with an early activation of PIP2-PLC by the insecticide, producing a depletion of the PIP2 pool previous to the stimulation with carbachol. These changes take place simultaneously with a decrease in the ability of Bufo arenarum oocytes to be fertilized in vitro, suggesting a correlation between impairment in the PIP2 cascade and a decrease in the fertilization rate.

1-Phosphatidylinositol 4-Kinase↗
PubMed2003

Different fertilization rates between immotile testicular spermatozoa and immotile ejaculated spermatozoa for ICSI in men with Kartagener's syndrome: case reports.

We report two cases of infertility treatment in couples where males suffered from Kartagener's syndrome (KS) and a total absence of motile sperm in the ejaculate. A total of three ICSI cycles was carried out. In all cycles, viable ejaculated or testicular spermatozoa were selected using the hypo-osmotic swelling (HOS) test. Case 1: In the first ICSI cycle total fertilization failure occurred after using ejaculated spermatozoa. In the following cycle testicular spermatozoa were used for ICSI, resulting in 75% fertilized oocytes and a pregnancy. Case 2: In the same ICSI cycle 50% of the oocytes were injected with ejaculated and 50% with testicular spermatozoa. The fertilization rates were 44 and 56% respectively and high quality embryos were achieved in both groups. One single embryo derived from testicular sperm was transferred with a resulting singleton pregnancy. In conclusion, testicular sperm for ICSI seem to have reliable fertilization capacity in men with KS, while ejaculated sperm, even if tested viable, seem more unpredictable. HOS test for selection of viable sperm for ICSI is recommended when ejaculated as well as testicular sperm are used for ICSI.

Adult↗
PubMedDate not supplied

Chromatin decondensation of human sperm in vitro and its relation to fertilization rate after ICSI.

The inability of sperm chromatin to decondense has been implicated in the failure of fertilization, This study was undertaken to identify the relationship between sperm chromatin decondensation in vitro after incubation with follicular fluid at various points in time and fertilization or pregnancy rates after intracytoplasmic sperm injection. Moreover, an attempt was made to determine whether this test could be used as a predictive test for the outcome of ICSI. Thirty-two infertile couples undergoing ICSI therapy were included in this prospective study. One milliter of semen from each sample was mixed with 1 mL of follicular fluid obtained from ICSI patients at the time of oocyte retrieval and incubated for 24 h. Many smears were made directly after semen liquefaction at the following time intervals: 30, 60, and 120 min and 24 h. Chromatin decondensation was evaluated with acridine orange staining. The mean percentage of uncondensed chromatin of spermatozoa in the native semen samples was 25 +/- 18.3%, which increased within 24 h to 91 +/- 9.5%. On the other hand, the fertilization and ongoing pregnancy rates were 64 +/- 21.7% and 20%, respectively. However, no correlations were found between chromatin decondensation at various point of time (30, 60, and 120 min and 24 h) and fertilization rate. No correlation was shown between the chromatin decondensation and sperm counts in the ejaculate. morphology, or the percentage of condensed chromatin. In light of this study, chromatin decondensation in vitro cannot be recommended for predicting the fertilization potential of spermatozoa and pregnancy rates in the ICSI program. Further research is necessary, especially in cases where ICSI is being considered as a therapeutic option.

Adult↗
PubMed1984

Reduction in fertilization rate in vitro of oocytes from immature rats induced to superovulate.

Immature female rats (65-70 g) were injected with 4 i.u. PMSG (control) or superovulated with 8, 16, 24 or 40 i.u. PMSG and were killed 68-70 h later, shortly after the normally expected time of ovulation. Oocytes were recovered from the oviducts and inseminated in vitro. After 18 h oocytes were counted and classed as degenerate or 1-cell. Mean numbers of oocytes recovered were 8.2, 26.8, 50.7, 38.7 and 38.5 for each dose of PMSG respectively. The 1-cell oocytes were assessed for sperm penetration of the vitellus and pronuclear development and later for development to the 2-cell stage. Fertilization rates at the 1-cell stage were 76.8, 62.9, 53.6, 52.2 and 44.5% for the rats treated with 4, 8, 16, 24 and 40 i.u. respectively (P less than 0.001). On average, 91% of fertilized 1-cell oocytes developed to the 2-cell stage and there was no difference between treatments in this respect. Significantly more of the unfertilized oocytes were degenerate in the rats treated with 24 or 40 i.u. PMSG (34.6 and 50.4%) than in those treated with 4, 8 or 16 i.u. (7.0, 13.9, and 7.5%) (P less than 0.001). When rats were killed 63-65 h after PMSG, just before the normally expected time of ovulation, some of the rats treated with 24 and 40 i.u. PMSG had partly ovulated: of the oocytes recovered from the oviducts only 12.3% (24 i.u.) and 26.6% (40 i.u.) were fertilized. These results demonstrate that proportionately fewer oocytes recovered from superovulated rats are competent to undergo in-vitro fertilization than are oocytes recovered from control rats.

Animals↗
PubMed1975

[Study of the influence of some factors on conception and fertility rates in sheep in the anestrus period].

Experiments were carried out with a total of 520 sheep, two-breed crosses, during the anestrus period (January-May) in 1972 and 1973. Estrus was induced by means of hormonal preparations, such as implants (Silestrus), vaginal swabs (Veramix), pregnant mare sera (Rigaoux) as well as estradiol-valerianat. Both the test and the control groups of animals were divided into four lots to study: a. the effect of the interval following lambing and the season on the results of hormonal treatment; b. the conception and fertility rates in lactating ewes with weaned lambs in the anestrus period; c. the effect of hormonal treatment in young and adult ewes nursing single lambs or twins and d. the influence of the functional status on the results of hormonal treatment.

Age Factors↗
PubMed1995

High fertilization rate with intracytoplasmic sperm injection in mosaic Klinefelter's syndrome.

With the introduction of intracytoplasmic sperm injection (ICSI) as a practical successful treatment for male infertility, we are able to offer the procedure to a group of patients who probably could never father a child of their own. From a patient with mosaic Klinefelter's syndrome, sufficient motile sperm for intracytoplasmic sperm injection were obtained from a fresh ejaculate estimated to contain < 100 motile sperm. In the first IVF-ICSI attempt, out of seven oocytes that were collected from the wife, four were mature and were injected by ICSI. Fertilization occurred in all four oocytes but only one cleaved and was transferred to the uterus. Pregnancy test was negative 16 days after ET. In the second treatment cycle four out of eight oocytes were selected for ICSI. All four fertilized, three cleaved at the right time, and two were transferred into the wife's uterus. One embryo was frozen. Pregnancy test 16 days after ET was negative. The high fertilization rate achieved in this case indicates the potential of ICSI to treat extreme male infertility. Its use offers hope to those patients with conditions previously considered to be untreatable.

Adult↗
PubMed1997

An artificially induced follicle stimulating hormone surge at the time of human chorionic gonadotrophin administration in controlled ovarian stimulation cycles has no effect on cumulus expansion, fertilization rate, embryo quality and implantation rate.

In the spontaneous menstrual cycle, the mid-cycle gonadotrophin surge causes maturation of the cumulus-oocyte complex, mucification of cumulus cells and expansion of the cumulus oophorus, resumption of meiosis and maturation of the cytoplasm of the oocyte. Whether this is an effect purely of luteinizing hormone (LH) or whether follicle stimulating hormone (FSH) also plays a role is unknown. The effect of an artificially induced FSH surge at the time of human chorionic gonadotrophin (HCG) injection on maturation of the cumulus-oocyte complex was investigated in a prospective randomized double-blind trial. Twelve patients underwent controlled ovarian hyperstimulation [long gonadotrophin-releasing hormone agonist (GnRHa)/human menopausal gonadotrophin (HMG) protocol] for in-vitro fertilization (IVF) treatment. At the time of HCG administration, six patients received a bolus injection of FSH (450 IU i.m.); the other six patients received a placebo. The peak plasma concentrations of FSH of the experimental group were compared with the peak values of FSH obtained at the mid-cycle gonadotrophin surge of the natural cycle of a group of 12 volunteers to validate the bolus injection of FSH. Maturation of the cumulus-oocyte complex was quantified by measuring the expansion of the cumulus, by the fertilization rate and the implantation rate. The quality of the embryos was scored according the average morphology score. The bolus injection of FSH mimicked the mid-cycle gonadotrophin surge. The mean peak value of FSH (12.9 IU/l) in the experimental group was fully comparable with the mean peak value of FSH (10.0 IU/l) of the mid-cycle gonadotrophin surge in the natural cycle. No effect of a bolus injection of FSH on the maturation of the cumulus-oocyte complex or any other outcome variable was found. It is not advantageous to combine the final HCG injection with a bolus injection of FSH in GnRHa/HMG stimulated cycles.

Adult↗
PubMed2000

Pregnancy-associated breast cancer: a case-control study in a young population with a high-fertility rate.

Pregnancy-associated breast cancer (PABC) is not a rare event. The association frequently imposes a management challenge. We intended to review the clinical features, therapy, and outcome of patients with PABC seen at a single institution over a five-year period and to compare those with that seen in a matched control group. Data of all patients with PABC diagnosed during pregnancy were retrospectively reviewed (Group I). For each patient in Group I, three matched controls with breast cancer without pregnancy were identified (matched for age, stage, and year of diagnosis, Group II). 72 patients in Group I and 216 in Group II were identified. Their median age was similar (34 vs 35 y, respectively). The median number of prior pregnancies for patients in Groups I and II was 5. Patients had shorter duration of symptoms prior to diagnosis as compared with their controls (5.6 vs 9.4 months, P < 0.0001). 3%, 31%, 40%, and 26% of patients had Stage I to IV, respectively. A pattern that was similar to that seen in our breast cancer population. Pregnancy was terminated in 34 patients (47%), while 38 (53%) had normal spontaneous vaginal delivery. 47 patients in Group I had surgery; 37 (52%) had modified radical mastectomy and 10 (14%) had conservative surgery. In 37 patients surgery was performed after termination of pregnancy and 10 had surgery performed during pregnancy. The median number of positive lymph nodes in Group I was 4 as compared with 2 for patients in Group II. No patients in Group I had systemic chemotherapy during first trimester, while only 4 (6%) and 3 (4%) received adjuvant or neoadjuvant during second and third trimester, respectively. No congenital malformation in the newborns was diagnosed. None of the patients in Group I received radiotherapy during pregnancy. Over a median of 47.5 months, 48 (67%) patients in Group I were alive as compared to 126 (58%) in Group II, with no difference in the median survival (P= 0.79). Comparing overall survival (OS) between the two groups stage for stage also showed no significant difference. Also there was no difference in progression-free survival between the two groups. Cox proportional hazard model identified advanced stage as the only independent adverse prognostic variable that influenced OS in Group I. Despite that this series included a relatively young population with a high fertility rate, the study confirmed the lack of a survival difference between patients with PABC and their matched controls.

Abortion, Induced↗
PubMed2004

The effect of a two-hour, room temperature incubation of human spermatozoa in TEST-yolk buffer on the rate of fertilization in vitro.

PURPOSE: To reassess the use of TEST-yolk buffer (TYB) in an in vitro fertilization (IVF) program by comparing fertilization rates achieved in a glucose-free cleavage medium by the standard IVF preparation of sperm versus a 2-h, room temperature incubation of sperm in TYB. METHODS: Oocytes collected for IVF were randomly split into two groups and inseminated with either TYB-treated sperm or IVF-prepared sperm. SETTING: Stanford Reproductive Endocrinology and Infertility Center. PATIENTS: Fifty couples undergoing IVF with at least 10 mature oocytes. MAIN OUTCOME MEASURES: Fertilization rates in vitro. RESULTS: Fertilization rates were significantly higher (p = 0.015) with TYB treatment. The average 2PN fertilization rate was 49.6% (188/379) for the IVF group and 57.4% (221/385) in the IVF with TYB group. CONCLUSIONS: A 2-h, room temperature incubation of sperm in TYB produces significantly higher 2PN fertilization rates as compared to standard IVF preparation of sperm in a current generation cleavage medium.

Culture Media↗