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G Ndukwe

Publications and source records attributed to G Ndukwe.

9 recordsLinked to original sources
PubMed2000

The progesterone receptor and ubiquitin are differentially regulated within the endometrial glands of the natural and stimulated cycle.

The initiation of human pregnancy requires precisely timed development of the endometrium to receive the implanting blastocyst. The ovarian steroid hormones are essential for development and maintenance of a hospitable uterine environment. The hormonal regimes employed in assisted reproduction procedures are known to alter the abundance of specific endometrial receptors for these steroids. Since, in the presence of ligand, the progesterone receptor (PR) is known to be modified by the small intracellular protein ubiquitin, we have investigated the localization of ubiquitin and PR within the endometrial glands of 28 fertile women during a monitored menstrual cycle and also during a stimulated cycle prior to oocyte donation. We have also observed the number of gland cells undergoing cell division as demonstrated by the presence of Ki67 immunostaining. We demonstrate that the percentage of ubiquitin-positive nuclei increases from day four post-ovulation to day 10 post-ovulation in the natural cycle, but that this increase is not seen during a stimulated cycle. The presence of PR within glandular epithelium and the proliferation of gland cells were only observed during the early secretory phase and did not appear to vary significantly between the two cycles. We conclude that ubiquitin may play an important role in endometrial development and that perturbation of ubiquitin may be related to the lower implantation rate seen in the stimulated cycle.

Adult↗
PubMed1998

The predictive value of the zona-free hamster egg penetration test in relation to in-vitro fertilization at various insemination concentrations.

The aim of the study was to evaluate the predictive value of the zona-free hamster egg penetration test (ZHEPT) for success in in-vitro fertilization (IVF) at various insemination concentrations ranging between 0.1 and >0.6 x 10(6)/ml. The ZHEPT was assessed using sperm samples from 87 couples undergoing IVF treatment. A similar test was simultaneously performed on the same semen sample following ionophore induction of the acrosome reaction (ZHEPTii test). Both the tests were poorly correlated with the fertilization rate of IVF at all the insemination concentrations except at >0.6 x 10(6)/ml, when there was good correlation between the ZHEPTii test and the fertilization rate. Following exclusion of two cases with an oocyte problem, further statistical analysis revealed that both the ZHEPT and ZHEPTii tests were poorly correlated with fertilization rate in IVF in this treatment group. This study suggests that the ZHEPT (with and without ionophore induction of the acrosome reaction) has a poor predictive value for the success of fertilization in IVF treatment at any insemination concentration.

Adult↗
PubMed1997

Severe ovarian hyperstimulation syndrome: is it really preventable by prophylactic intravenous albumin?

OBJECTIVE: To evaluate the effectiveness of i.v. albumin in preventing severe ovarian hyperstimulation syndrome (OHSS) in patients at risk. DESIGN: Retrospective review and data analysis. SETTING: University-based tertiary referral center for assisted reproductive technologies (ART). PATIENT(S): Sixty women at high risk of developing severe OHSS after superovulation for ART. INTERVENTION(S): One liter of albumin (4.5%) administered i.v. during oocyte retrieval and immediately afterward. RESULT(S): Of the 60 women who had prophylactic i.v. albumin, 5 (8%) developed severe OHSS, which led to hospitalization. Eight (13%) developed moderate OHSS. Forty-seven (78%) did not develop any symptoms. Four of the 5 women who developed severe OHSS had ET and 3 of them (75%) were pregnant (1 twin and 2 singletons). CONCLUSION(S): Intravenous albumin administered at oocyte retrieval does not prevent the occurrence of severe OHSS, especially in cases associated with pregnancy. It is important that clinicians are not lured into a false sense of security by the early report, full of promise, on the use of i.v. albumin to prevent severe OHSS.

Albumins↗
PubMed1997

'Curing' empty follicle syndrome.

We report a novel method of rescuing empty follicle syndrome (EFS) and provide evidence that it is a drug-related problem rather than a clinical dysfunction. In a preliminary study we established that in EFS the serum beta-human chorionic gonadotrophin (beta-HCG) concentrations 36 h after HCG administration never exceeded 10 mIU/ ml. beta-HCG concentrations were thus used to confirm EFS when oocytes were not retrieved from one ovary after controlled ovarian hyperstimulation. The procedure was suspended leaving intact all follicles in the second, ovary. After confirmation of EFS, a second HCG from a different batch was administered and 36 h later mature oocytes were retrieved from the intact ovary, suggesting a fault with the HCG previously administered. Three patients have been treated in this way. In the first case, four out of five mature eggs were fertilized after intracytoplasmic sperm injection (ICSI) resulting in the transfer of three top grade (grade 1) embryos. In the second case all seven mature oocytes fertilized after in-vitro fertilization (IVF) and three grade 1 embryos were transferred resulting in a twin pregnancy, now delivered. In the third case, five out of nine oocytes were fertilized after ICSI and one out of the three treated with high insemination concentration IVF fertilized, resulting in the transfer of three ICSI embryos.

Chorionic Gonadotropin↗
PubMed1996

Predicting empty follicle syndrome.

OBJECTIVE: To determine a simple predictive test for empty follicle syndrome before oocyte retrieval. DESIGN: Retrospective correlation analysis. SETTING: Patients attending Nottingham University Research and Treatment Unit, a tertiary, university-based assisted reproductive technologies (ART) program between April 1, 1994 and March 31, 1995. PATIENT(S): Six women in whom no oocytes were retrieved after superovulation for ART (empty follicle syndrome) were compared with 11 women with successful oocyte retrieval. INTERVENTION(S): Subcutaneous buserelin acetate plus IM hMG and hCG were used for superovulation. Oocyte retrieval was transvaginal and ultrasound guided. MAIN OUTCOME MEASURE(S): Ultrasound measurement of follicular growth and serum E2 levels during superovulation. Serum beta-hCG levels before and 36 hours after hCG administration IM. Number of oocytes retrieved. RESULT(S): Before hCG administration, beta-hCG was not detectable in the serum. The serum beta-hCG 36 hours after hCG was 209 +/- 16.7 mIU/mL (conversion factor to SI units, 1.0; mean +/- SEM, range 106 to 290 mIU/mL) in women with successful oocyte retrieval and 4 +/- 1.8 mIU/mL (range 0 to 9 mIU/mL) in empty follicle syndrome. This difference was significant. CONCLUSION(S): Empty follicle syndrome is associated with very low bioavailability of beta-hCG and can be predicted by measuring serum beta-hCG level 36 hours after IM hCG administration.

Adult↗
PubMed1987

Endocrine changes following pituitary desensitization with LHRH agonist and administration of purified FSH to induce follicular maturation.

Pituitary desensitization was induced in 13 normally menstruating women by administration of an LHRH agonist, Buserelin, intranasally, 100 micrograms at intervals of 4 h, for a period of 14 days starting on day 22 of the menstrual cycle. Whilst continuing with Buserelin, multiple follicular development was induced by administration of purified FSH (Metrodin) for between 8 and 15 days at a dose of 150 i.u. daily. In one patient no follicular growth was induced after 14 days treatment. In the remaining subjects between 3 and 11 follicles with mean diameter greater than 16 mm were stimulated and between 2 and 10 mature oocytes were recovered laparoscopically for IVF, 34 h after hCG administration. Eight patients underwent embryo transfer and four conceived.

Adult↗
PubMed1987

Attempts to stimulate multiple follicular growth for IVF by administration of pulsatile LHRH.

Administration of pulsatile LHRH (14.4 microgram/pulse per 90 min) from day 5 to 9, or day 7 to 11 of the cycle following clomiphene pretreatment on days 2-6 induced multiple follicular growth for oocyte recovery for in vitro fertilisation. Administration of LHRH without clomiphene pretreatment failed to induce multiple follicular development. The same group of patients treated with clomiphene alone had fewer numbers of mature follicles, fewer oocytes recovered and less pre-embryos for transfer than when treated with clomiphene and LHRH in combination. Peak gonadotrophin release following commencement of LHRH was seen within the first 24 h of administration with a gradual fall in both LH and FSH toward baseline pretreatment values by the fourth day of administration. A discernible LH increment to LHRH was still present on the fourth day of LHRH treatment, but in many individuals no FSH increment was observed. The preovulatory oocytes recovered were predominantly mature with fertilisation rates of 70% and 85.7% for the two regimens. No pregnancy occurred in the six patients who underwent pre-embryo transfer.

Adult↗
PubMed1986

Stimulation of multiple follicular growth for in vitro fertilization by administration of pulsatile luteinizing hormone-releasing hormone during the midfollicular phase.

Pulsatile subcutaneous administration of LH-RH (14.4 micrograms/pulse/90 minutes) during the midfollicular phase (days 7 to 11) of the cycle induced significant increases in circulating LH, FSH, and E2 in all eight women treated. When CC (150 mg/day on days 2 to 6) was administered prior to the LH-RH, multiple follicular development occurred, five to seven mature follicles (greater than 16 mm) being found on day 12 of the cycle. The administration of pulsatile LH-RH in this manner may prove to be an additional regimen for use in IVF programs.

Adult↗