Biomedical subjects

K Benfer

Publications and source records attributed to K Benfer.

5 recordsLinked to original sources

PubMed1997

11 beta-Hydroxysteroid dehydrogenase enzyme activity in granulosa cells derived from ovarian follicles of in vitro fertilization patients.

11 beta-Hydroxysteroid dehydrogenase (HSD) activity was measured in freshly frozen granulosa cells isolated from follicles of twenty-one infertility patients undergoing in vitro fertilization-embryo transfer (IVF-ET). A total of 213 follicles were analyzed for 11 beta-HSD activity. Both nicotinamide-adenine dinucleotide (NAD) and nicotinamide-adenine dinucleotide phosphate (NADP) dependent 11 beta-dehydrogenase activities were measured in granulosa cells. The activity in reductive direction (11-oxoreductase activity) was not measurable either with NADH or NADPH as cofactors. NAD- and NADP-dependent dehydrogenase activities are in comparable levels at 100 nmol/l and 1 mumol/l corticosteroid concentrations. For comparing enzyme activities of individual follicles, significant enzyme activity was considered to be a level of > 2 nmol/l/min/mg. 41.3% of the follicles demonstrated enzyme activity, 58.7% did not. The mean 11 beta-dehydrogenase (11 beta-DH) activity was calculated for each patient. Those patients with levels > 2 nmol/l/min/mg were considered enzyme positive; those with mean levels < 2 nmol/l/min/mg were considered negative. No significant association was noted between follicle size, oocyte maturity or fertilization rates and 11 beta-DH activity. This study noted the presence of 11 beta-DH activity in granulosa cells, however, no association with oocyte maturity and fertilization was found.

11-beta-Hydroxysteroid Dehydrogenases↗

PubMed1996

Transfer of cryopreserved embryos improved pregnancy rates in patients with damage to the functional integrity of the sperm membrane as measured by the hypo-osmotic swelling test.

OBJECTIVE: To compare the pregnancy rates (PRs) after transfer of cryopreserved embryos in patients who have damage to the functional integrity of the sperm membrane as measured by the hypo-osmotic swelling test to those without this defect. DESIGN: Prospective clinical study. SETTING: University-associated IVF center. PATIENTS: Fifty-four patients enrolled in a matched prospective study to evaluate the effects of low HOS scores (<50%) on PRs after IVF-ET were followed to determine the PR after transfer of cryopreserved embryos. MAIN OUTCOME MEASURE: Clinical PRs and implantation rates. RESULTS: Fourteen patients with low hypo-osmotic swelling test scores underwent 21 frozen ET cycles, achieved for clinical pregnancies for a PR per cycle of 19.0% and an implantation rate of 7.1%. Twelve patients with normal hypo-osmotic swelling test scores underwent 21 frozen ET cycles, achieved five preganancies for a clinical PR per cycle of 23.8% and an implantation rate of 9.3%. CONCLUSION: Previous studies have demonstrated an adverse effect of low hypo-osmotic swelling test scores on PRs after IVF-ET despite normal fertilization. This adverse effect was not found in the transfer of cryopreserved embryos from males with hypo-osmotic swelling test scores. Further investigation is required to determine how cryopreservation improves the chances of implantation of these embryos.

Cell Membrane↗

PubMed1995

A comparative prospective study using matched samples to determine the influence of subnormal hypo-osmotic test scores of spermatozoa on subsequent fertilization and pregnancy rates following in-vitro fertilization.

The achievement of pregnancies in vivo is rare in couples where the male partner has defective sperm membranes as shown by hypo-osmotic swelling (HOS) test scores of < 50%. However, there have been mixed reports on the value of the HOS test in predicting outcome following invitro fertilization; some studies suggest reduced fertilization rates and others find little, if any, predictability of decreased fertilization. The assumption has been made that fertilization rates are proportional to pregnancy rates; however, this may not necessarily be true since defective spermatozoa could lead to a less viable pre-embryo and therefore a decreased viable pregnancy rate. We performed a comparative prospective study using matched controls to evaluate fertilization rates and to determine subsequent pregnancy rates. The mean HOS scores were 70.0 and 36.7% respectively, with mean motile sperm concentrations of 35.7 and 34.0 x 10(6)/ml in 27 matched pairs. There was no difference in the mean number of oocytes retrieved, fertilization rates or number of embryos transferred between the two groups by HOS score. The clinical and viable pregnancy rates and implantation rates were 25.9, 18.5 and 9.9% for normal versus 3.7, 3.7 and 1.1% for subnormal groups. These data suggest that low HOS scores may be associated with the formation of defective embryos, leading to low pregnancy rates but normal fertilization rates.

Female↗

PubMed1995

Chymotrypsin-galactose treatment of sperm with antisperm antibodies results in improved pregnancy rates following in vitro fertilization.

PROBLEM: To determine if chymotrypsin-galactose (CG) treatment of sperm bound with antisperm antibodies (ASA) improves pregnancy rates (PRs) following in vitro fertilization (IVF). METHOD: Patients with > 50% ASA who failed to conceive despite six intrauterine insemination (IUI) cycles were included. Initially the sperm treatments were randomized with CG vs culture medium; subsequently only CG treatment was used. RESULTS: There was a significantly lower fertilization rate in those patients inseminated with sperm incubated in culture medium vs CG (27% vs 47%, P < .05 t-test). Similarly, a higher percentage of patients receiving culture medium treatment of sperm had failed fertilization (45%) compared to CG (11%). Though the clinical PRs were higher with CG (21%) tham medium (9.5%), there was no statistical difference. CONCLUSIONS: Though the percentage of sperm bound with antibodies are not reduced, we hypothesize that the CG treatment improves fertility by possibly mitigating the antagonistic action of these antibodies.

Autoantibodies↗

PubMed1994

Comparison of the cumulative probability of pregnancy after in vitro fertilization-embryo transfer by infertility factor and age.

OBJECTIVE: To compare the cumulative probability of pregnancy after multiple IVF cycles by age and cause of infertility. DESIGN: A prospective study was done in which patients were followed from the time they registered for their first IVF cycle until they achieved a clinical pregnancy, withdrew from treatment, or study was terminated. PATIENTS, SETTING, TREATMENTS: Infertile women undergoing IVF-ET at the Cooper Institute for In Vitro Fertilization were enrolled in this study if the luteal phase leuprolide acetate (LA) and hMG controlled ovarian hyperstimulation (COH) regimen was used. MAIN OUTCOME MEASURES: Clinical pregnancy, as determined by a positive beta-hCG level and ultrasonographic confirmation of a gestational sac, and delivery rates based on number of women with live births were compared by infertility factor and age. RESULTS: The 3-month cumulative probability of pregnancy based on life table analysis was 33% in women with tubal factor who were < or = 35 years of age, 25% in women with tubal factor who were > 35 years of age, 30% for women with multiple factors who were < or = 35 years of age, and 14% for women with multiple factors who were > 35 years of age. The rate for the older women with multiple factors was significantly lower than that for the other groups. The delivery rates were lower for the women with multiple factors than for women under 35 with tubal factor only. CONCLUSIONS: There is a significant effect of age and infertility factor on pregnancy and delivery rates. Physicians should consider these factors in evaluating their patients' prospects for success in IVF-ET.

Adult↗