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Biomedical subjects

J D Stanger

Publications and source records attributed to J D Stanger.

28 records · Page 2Linked to original sources
PubMed1984

Failure of human oocyte release at ovulation.

Among 150 patients admitted for ovum aspiration, in vitro fertilization, and embryo transfer in Perth, Western Australia, 14 were found to have had at least one ovulated follicle at the time of laparoscopy. Based upon ultrasound estimation of follicle diameter 24 hours previously, ovulation occurred in 6 of 22 follicles less than 1.7 cm in mean diameter and in 16 of 19 follicles greater than 1.7 cm in mean diameter. When the ruptured follicles were flushed with heparinized fertilization medium, oocytes were collected in 13 of the 22 dispersed follicles. Twelve oocytes developed pronuclei 16 hours after the addition of spermatozoa, and 11 cleaved to the 4-cell stage within 44 hours of insemination. Oocytes were recovered from 6 of 11 patients stimulated with clomiphene alone and from all 3 patients stimulated with clomiphene supplemented with human menopausal gonadotropin. These observations suggest that oocyte release and follicle rupture are not necessarily synonymous events and that the incidence of retained oocytes in ovulated follicles following stimulation with clomiphene or clomiphene plus human menopausal gonadotropin could be on the order of 60%.

Clomiphene↗
PubMed1984

Assessment and hormonal treatment of the luteal phase of in vitro fertilization cycles.

Luteal phase lengths and hormonal profiles (progesterone, oestradiol-17 beta, beta HCG and prolactin) have been documented in 77 cases derived from a series of patients undergoing IVF. Nineteen pregnancies were generated during this series and 12 healthy infants have already been delivered. Luteal phase lengths were 14.5 +/- 0.5 days with 14.3% demonstrating mid-luteal progesterone levels of less than 31 nmols/l, considered to be low for successful conception. A random study of luteal support regimens comparing HCG or medroxyprogesterone acetate (MPA) with nil therapy was studied in a series of 44 consecutive embryo transfers during which 10 pregnancies were achieved. No difference was noted in the pregnancy rates for the 3 groups but the pregnancy outcome was better in those who had HCG support and this was more apparent in the overall series of 19 pregnancies. A significant luteotrophic effect was noted with HCG support regimens whilst MPA appeared to have a luteal suppressant action. Six pregnancies which aborted with blighted ova were derived from cycles in which the luteal phase progesterone levels were low raising the possibility that a poor hormonal environment may predispose to blighted ova.

Abortion, Spontaneous↗
PubMed1984

Combined pregnancy after gonadotropin therapy.

Three cases of combined pregnancy are described after gonadotropin therapy; two cases after human pituitary gonadotropin and one after human menopausal gonadotropin administration. In each case the intrauterine gestation was a multiple pregnancy. After salpingectomy, two of the women have proceeded to the delivery of healthy infants; the third woman aborted. In each case the gonadotropin stimulation regimen was ceased at the appropriate stage when the estriol excretion was between 60 and 125 micrograms/day, but the subsequent rate of rise of estriol was 2.3- to 3.2-fold during the coasting phase before the human chorionic gonadotropin trigger when the estriol excretion rate was 140 to 350 micrograms/day.

Abortion, Spontaneous↗
PubMed1984

Monozygotic twins from in vitro fertilization.

A case of identical twins following in vitro fertilization and embryo transfer ( IVF -ET) is described. Two embryos were transferred, but it is apparent that only one implanted and subsequently divided in the early implantation phase to produce identical male twins within a monochorionic , diamniotic placental and membrane configuration. Additional marker studies provide an overall probability of less than 0.001 for dizygosity . There is unlikely to be any relationship between this event and the technique of IVF -ET.

Adult↗
PubMed1983

The relationship between motility and the FITC-BSA binding properties of mouse epididymal spermatozoa.

Mouse epididymal spermatozoa exposed to fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) immediately following dilution or after a 2-hour incubation period under fertilization conditions, were assessed by fluorescence microscopy for albumin adsorption. Motile spermatozoa exhibited light fluorescence in the midpiece and tail but not in the head. In contrast the majority of nonmotile spermatozoa displayed a strong and characteristic fluorescence in the post acrosomal region of the sperm head as well as the midpiece. Spermatozoa immobilised by short-term heat stress exhibited fluorescence in the post acrosomal region and midpiece as before but also in the acrosomal cap. The equatorial region failed to fluoresce. The significance of these observations on the involvement of albumin in capacitation is discussed.

Acrosome↗
PubMed1982

Effect of polyamines on fertilization of mouse ova in vitro.

After a 1-hour preincubation of epididymal mouse spermatozoa at a concentration of 2 X 10(6)/ml in 0.23 mM spermine, the proportion of F1(C57BL X CBA) mouse ova fertilized after 1 and 2 hours was significantly greater than with untreated spermatozoa. Spermine also significantly increased the proportion of ova fertilized at the sub optimal sperm concentration of 2 X 10(5)/ml. The stimulatory effect was lost when the protein source in the fertilization medium was changed from human serum albumin V (HSA) to HSA crystalline. This provides indirect evidence that albumin is directly involved in the capacitation process and that the crystalline is more potent than the fraction V preparation. At equimolar concentrations, spermidine was partially and putrescine was totally inhibitory to fertilization. Mechanisms whereby spermine may affect metabolic activity or sperm-zona binding are discussed. It is suggested spermine may also be present in ovulatory fluid and therefore could potentially be involved in fertilization in vivo.

Animals↗
PubMed1982

Interaction of semen with ova in vitro.

Spermine had a beneficial effect on the fertilization of zona-free mouse ova in vitro. A deleterious effect of spermine or seminal plasma on gametes only occurred if normal, untreated BSA was present in the incubation medium. This was due to the activity of spermine oxidase, which could be assayed in the untreated BSA and which was removed by TCA-purification of the BSA. The addition of a spermine oxidase inhibitor, isoniazid, or the use of the TCA-purified BSA preparation allowed the direct effects of spermine or seminal plasma on mammalian fertilization to be assessed. Human seminal plasma retarded the acquisition of fertilizing ability in human spermatozoa and prevented it in mouse spermatozoa. The fertilizing ability of the spermatozoa of both species was unaffected, when spermatozoa were preincubated to achieve capacitation before adding the seminal plasma.

Animals↗
PubMed1981

Fertilization of pronase-treated mouse ova in vitro.

In order to obtain consistently a large number of zona-free mouse ova for studies of sperm-egg interactions, a study was made of the relative effectiveness of removing the zona pellucida from ova by mechanical or enzymatic treatments. Ova exposed to pronase before mechanical removal of the zona pellucida in medium devoid of pronase had similar fertilization rates in vitro compared with ova mechanically denuded in the absence of pronase. Ova with pronase-weakened zonae were easier to denude and survived the mechanical manipulations better than the ova denuded by vigorous aspiration in narrow-bore pipettes. However, exposure to pronase did significantly lower the incidence of polyspermy in the naked ova, indicating that some of the enzyme may have diffused across the perivitelline space and damaged sperm-binding sites on the vitelline plasma membrane. The enzyme treatment also reduced the fertilization rate of zona-intact ova.

Animals↗