Biomedical subjects

Brian Dale

Publications and source records attributed to Brian Dale.

11 recordsLinked to original sources

PubMed2006

The effect of extended culture of cumulus-oocyte complexes in follicular fluid during in vitro fertilisation cycles.

PURPOSE: To assess the clinical and biological effect of the preincubation of oocytes in follicular fluid prior to IVF and ICSI cycles. METHODS: A series of patients were treated by the preincubation of oocytes in the patients' follicular fluid for 3 h after oocyte retrieval followed by processing with standard protocols. Control oocytes were preincubated in normal IVF culture medium. Fluorescence techniques were used to examine oocyte mitochondrial membrane potential. RESULTS: Fertilisation, pregnancy, and implantation rates were all significantly improved after the preincubation of oocytes in follicular fluid. Further tests suggested that differences in pH between follicular fluid and artificial culture medium may be critical to these differences. CONCLUSIONS: Preincubation of human oocytes in follicular fluid improves the results after IVF. This may be partly due to the use of a non-"physiological" pH in artificial culture media during in vitro fertilisation procedures.

Adult↗

PubMed2005

Clinical use of the perifollicular vascularity assessment in IVF cycles: a pilot study.

BACKGROUND: In Italy, a recent law has imposed a ban on the fertilization of more than three oocytes at one time, and all resulting embryos produced must be transferred simultaneously. The aim of the present controlled study was to assess the clinical feasibility and efficacy of the perifollicular vascularity assessment for oocyte selection in IVF cycles. METHODS: Fifty-four young primary infertile non-obese women (27 cases and 27 age- and BMI-matched controls) underwent IVF cycles. The choice of the oocytes to fertilize was performed according to perifollicular vascularization in the experimental group, whereas in the control group, the standard morphologic criteria alone were used. The dose of gonadotrophins used, the dominant follicles obtained, the duration of the ovarian stimulation, the number of oocytes retrieved, the number/quality of oocytes fertilized and of cleaved embryos, cycle cancellation, implantation, clinical pregnancy, ongoing pregnancy, multiple pregnancies and ovarian hyperstimulation syndrome rates were assessed in each group. RESULTS: The assessment of perifollicular vascularity was feasible in 88.9% of cases. No difference between groups was detected in any parameter evaluated. CONCLUSION: Power Doppler assessment of perifollicular vascularity seems to have no clinical utility for oocyte selection in IVF cycles for young infertile women.

Adult↗

PubMed2005

A randomized controlled trial evaluating metformin pre-treatment and co-administration in non-obese insulin-resistant women with polycystic ovary syndrome treated with controlled ovarian stimulation plus timed intercourse or intrauterine insemination.

BACKGROUND: There are few data in the literature regarding the utility of metfomin before and during gonadotrophin administration in women with polycystic ovary syndrome (PCOS). The aim of the present study was to assess the effect of the pre-treatment and co-administration of metformin in infertile PCOS women treated with controlled ovarian stimulation (COS) followed by timed intercourse (TI) or intrauterine insemination (IUI). METHODS: Seventy insulin-resistant primary infertile women with PCOS were randomized to receive metformin cloridrate (850 mg twice daily; group A) or placebo tablets (two tablets daily; group B) for 3 months. Three trials of COS using highly purified urinary FSH (hpFSH) plus TI/IUI were performed. Number of ampoules of gonadotrophin used, duration of the ovarian stimulation, cycle cancellation, ovulation, pregnancy, abortion, live birth, mono-ovulatory cycles, multiple pregnancies and ovarian hyperstimulation syndrome (OHSS) rates were assessed. RESULTS: No difference between groups was detected in ovulation, cycle cancellation, pregnancy, abortion, live birth, multiple pregnancies and OHSS rates. The mono-ovulatory cycle rates were significantly (P = 0.002) more frequent in group A than in group B, whereas the days of stimulation for non-cancelled cycles and the number of vials of gonadotrophins used were significantly (P < 0.001) higher in group A than in group B. CONCLUSION: In insulin-resistant women with PCOS, metformin pre-treatment and co-administration with hpFSH increases the mono-ovulatory cycles.

Adult↗

PubMed2005

The maternal age effect: a hypothesis based on oxidative phosphorylation.

The 'maternal age effect' in human reproduction, characterized by a negative relationship between maternal age and reproductive efficiency, remains a poorly understood phenomenon. Current data suggest that oocyte physiology determines this relationship. In this review, we present a hypothesis of a mitochondrial role in the physiology of ageing in human oocytes. We suggest that the efficiency of oxidative phosphorylation in the ageing human oocyte is degraded by free radical attack on the primordial oocytes residing in the ovary. Although deficiencies in oxidative phosphorylation can be accounted for in the short term by anaerobic respiration, we suggest that, in the long term, the level of oxidative phosphorylation strongly influences oocyte quality.

Female↗

PubMed2004

Secondary male factor infertility after Roux-en-Y gastric bypass for morbid obesity: case report.

Surgical treatments such as the Roux-en-Y gastric bypass operation result in the successful treatment of morbid obesity; however, this type of operation may cause long-term side effects due to the reduced absorption of nutrients. Here, we present data suggesting that this operation can result in secondary infertility in males. Six healthy, previously fertile male subjects presented in our centre for secondary infertility after a Roux-en-Y gastric bypass operation for morbid obesity. Reproductive function was assessed with a series of spermiograms, and by testicular biopsy. Secondary azoospermy with complete spermatogenic arrest was diagnosed. The results suggest that weight reduction surgery may cause reproductive dysfunction.

Adult↗

PubMed2004

Preimplantation genetic diagnosis for the treatment of failed in vitro fertilization-embryo transfer and habitual abortion.

OBJECTIVE: To apply preimplantation genetic diagnosis (PGD) for the treatment of patients with a history of failed IVF-ET or habitual aborters. DESIGN: Prospective clinical study. SETTING: Tertiary center for assisted reproduction. PATIENT(S): Ninety-four couples with failed IVF-ET after >2 IVF cycles and 64 couples with >2 spontaneous abortions. INTERVENTION(S): Patients were prepared for oocyte retrieval using standard controlled ovarian hyperstimulation protocols after standard laboratory techniques. Blastomeres from 6- to 8-cell embryos were analysed using fluorescence in situ hybridization with commercial chromosomal probes, and normoploid embryos were transferred on day 3 after fertilization. MAIN OUTCOME MEASURE(S): Pregnancy and implantation rates and live births. RESULT(S): Both 3- and 5-probe PGD resulted in a significantly higher outcome than controls for failed IVF-ET. Five-probe PGD appeared to be more suitable for habitual aborters. CONCLUSION(S): This pilot study suggests that 3-probe PGD is a valid option for failed IVF-ET patients. The use of five or more probes is indicated for habitual aborters.

Abortion, Habitual↗

PubMed2003

Radial alternating TE sequence for faster fat suppression.

This study describes a steady-state sequence that uses a radial k-space trajectory and alternating echo times (TEs) between even and odd k-space views. The sequence generated a single data set that was used to reconstruct images with inherent fat suppression. This fat suppression results from the fat phase variation in alternate echoes giving rise to cancellation in the central portion of k-space. This new fat-suppression method provides inherent fat suppression in half the acquisition time relative to the radial two-point Dixon method. The improvement in k-space sampling efficiency is demonstrated in phantom and clinical images, and through measured point-spread functions (PSFs). As a result, the radial alternating TE sequence offers improved temporal resolution over a radial version of the two-point Dixon sequence by requiring fewer total projections to obtain the same effective resolution in water-based tissues.

Adipose Tissue↗

PubMed2003

Chaotic mosaicism in human preimplantation embryos is correlated with a low mitochondrial membrane potential.

OBJECTIVE: To determine the relationship between the intrinsic mitochondrial deltapsi of human embryos and the embryo karyotype. DESIGN: Analysis of mitochondrial deltapsi of living embryos followed by chromosomal enumeration with fluorescence in situ hybridization. A tertiary center for assisted reproduction technology. PATIENT(S): Fifty-two patients attending the fertility center for assisted reproduction. INTERVENTION(S): Donated embryos were loaded with a mitochondrial deltapsi-sensitive fluorescence dye. MAIN OUTCOME MEASURE(S): Mitochondrial deltapsi was measured by confocal microscopy. Subsequently, embryos were fixed and fluorescence in situ hybridization analysis was used to denote embryo karyotype. MAIN OUTCOME MEASURE(S): Mitochondrial deltapsi and embryo karyotype. RESULT(S): An association was observed between low mitochondrial deltapsi and the detection of chaotic mosaicism. Analysis of oocytes suggested that this was due to the effect of low mitochondrial deltapsi on the morphology of the meiotic apparatus. CONCLUSION(S): The data suggest that the intrinsic mitochondrial deltapsi of human oocytes programs the developmental fate of embryos through an effect on the ability of oocytes to form a normal meiotic apparatus and not through nondisjunction.

Blastocyst↗

PubMed2002

Absence of sperm sex chromosome aneuploidies in an X0/XYY man.

OBJECTIVE: To determine appropriate genetic counseling of patients with a mosaic karyotype who wished to undergo assisted reproduction technology. DESIGN: Case report. SETTING: A tertiary center for assisted reproduction technology. PATIENT(S): A male with a mosaic karyotype X0/XYY. INTERVENTION(S): Analysis of ejaculated spermatozoa by using fluorescence in situ hybridisation with probes directed against chromosomes X, Y, and 18. MAIN OUTCOME MEASURE(S): Degree of sex chromosome aneuploidies in spermatozoa. RESULT(S): Levels of sex chromosome aneuploidies in spermatozoa were normal. On the basis of these findings, the couple proceeded to assisted reproduction technology without preimplantation genetic diagnosis and conceived a healthy male baby. CONCLUSION(S): Sex chromosome mosaicism in men does not necessarily lead to high levels of abnormal spermatozoa. Sex chromosome aneuploidies may be eliminated in the testes through the selective degeneration of abnormal spermatogenic cells.

Adult↗

PubMed2002

Zygote versus embryo transfer: a prospective randomized multicenter trial.

PURPOSE: To determine the efficiency of transferring human zygotes as opposed to human day 2 or 3 embryos. METHODS: A prospective, randomized, Multicenter trial. Patients were randomized into zygote or embryo transfer. Patients were prepared for oocyte retrieval using standardized protocols. Oocyte retrieval was performed under general anesthesia. Oocytes and spermatozoa were treated using standard laboratory techniques. All protocols were coordinated by the coordinating center. RESULTS: A total of 386 patients were included in the trial. Pregnancy rates were 36.5% after zygote transfer and 42% after embryo transfer. Implantation rates were equivalent (17%) in both groups. CONCLUSIONS: No general difference was observed for zygote or embryo transfer. The results suggest that zygote transfer is a valid alternative to embryo transfer.

Adult↗

PubMed2002

High outcome predictability after IVF using a combined score for zygote and embryo morphology and growth rate.

BACKGROUND: A scoring system has been developed to determine preimplantation embryo quality, and used to select embryos for transfer into the uterus of patients. METHODS AND RESULTS: The system was used to study early embryo development and to test whether these scores alone can accurately predict IVF outcome. Following zygote and embryo scores through early development, the data showed that a top quality zygote does not necessarily indicate that the resulting embryo will be top quality after in-vitro culture. The embryo quality score can change dramatically when embryos are cultured to day 2 or 3 post-fertilization. Pregnancy rates and implantation rates were compared with the cumulative and separated zygote and embryo scores. Analysis of the predictability of scoring systems suggested that morphological scores alone are relatively unpredictive of IVF outcome. When weighted for in-vitro growth rate, scores were highly predictive, more so than the rate of development alone. CONCLUSIONS: These data suggested that a combination of in-vitro growth rate and morphological analysis both of zygotes and embryos was highly indicative of outcome after IVF. The results can be adopted to the single embryo transfer approach to IVF.

Blastocyst↗