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Biomedical subjects

W R Edirisinghe

Publications and source records attributed to W R Edirisinghe.

At least 37 records · Page 2Linked to original sources
PubMed1990

Influence of pentoxifylline in severe male factor infertility.

Two in vitro fertilization sperm preparation protocols using pentoxifylline (long and short exposure before insemination) were studied in 57 couples (61 cycles) with male factor infertility. For each cycle, oocytes were divided into two groups for insemination using either pentoxifylline-treated or control semen. Fertilization rates improved over controls in the short protocol (P less than 0.001) and fewer couples experienced fertilization failure (P = 0.02). Sixteen pregnancies ensued (30% per collection with the short protocol), and 4 were from cases with less than 1.0 X 10(6) progressively motile sperm count per milliliter, 1 being as low as 0.2 X 10(6) progressively motile count per milliliter. Seventeen healthy infants have now delivered and pregnancy wastage is not increased. Pentoxifylline is thus a useful sperm treatment for cases of male factor infertility.

Clinical Trials as Topic↗
PubMed1989

Ultrastructural observations on gamete interactions using micromanipulated mouse oocytes.

Cumulus-free mouse oocytes were subjected to zona opening by cracking with microhooks (ZC) or acid drilling (ZD) and fixed 30-90 min after insemination (10(5) pre-capacitated motile sperms/ml). Ultrastructural observations were made on serially thin-sectioned oocytes: 15 ZC and 12 ZD. The zona lesion in ZC oocytes was a clean cut, whereas in ZD oocytes it formed a patchy area of partial zona loss, with reduced microvillar height on the underlying oocyte surface. Spermatozoa were observed within the perivitelline space and partially fusing with the oocyte after 30 min in both situations. Only acrosome-reacted sperm heads were observed to fuse: acrosome intact forms were generally in contact with the zona pellucida, either with the inner or outer surface. Acrosome-intact spermatozoa were also observed deeply embedded in the zona matrix, possibly indicating surface enzyme activity preceding the membrane fusion events of the acrosome reaction proper. The observations are consistent with the need for spermatozoa to make contact preferentially with the zona pellucida during the course of the acrosome reaction.

Acrosome↗
PubMed1989

Pituitary down-regulation using leuprolide for the intensive ovulation management of poor prognosis patients having in vitro fertilization (IVF)-related treatments.

A review of 118 treatment cycles in 115 women under prolonged GnRH analogue (GnRHa; leuprolide) treatment is presented. Patients were selected for treatment primarily on the grounds of poor previous response to stimulation (n = 40), advanced age (greater than 35 years; n = 29), previous premature luteinizing hormone (LH) surge (n = 30), polycystic ovarian disease (PCO; n = 12), and elevated androgens without evidence of PCO (n = 5). An overall pregnancy rate of 28.8% per treatment cycle was attained, compared with a pregnancy rate of 6.2% (6/97, of which none went to term) in the previous completed treatment cycle for the same patients. Ovarian response, as measured by oocytes recovered and maximum estradiol levels observed, was significantly improved in all groups and this was associated with a prolonged follicular phase, significantly more human menopausal gonadotropin (hMG) stimulation and a relatively high incidence of ovarian hyperstimulation, particularly in pregnant patients. Of specific techniques in the GnRHa cycle, GIFT produced a pregnancy rate per treatment of 50% (10/20); IVF-ET, 22% (8/36); PROST, 28% (13/46); and TEST, 19% (3/16). No cycles were abandoned, compared with a cancellation rate of 24% in previous cycles without GnRHa. Patients with PCO performed particularly well on GnRHa management, with a pregnancy rate per treatment of 58% (7/12). Pregnancy rates per treatment for the other groups were as follows: elevated age, 27% (9/33), high androgens, 40% (2/5); premature LH surges, 32% (9/28); and poor responders, 17.5% (7/40).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Volume of fluid and concentration of cations and energy substrates in the uteri of mice during early pseudopregnancy.

Estimates of the volume of fluid and the concentration of cations in the uterus were made by flushing the uterine cavity of mice mated to vasectomized males and measuring the concentrations of sodium and potassium cations in the recovered fluid. On day 1 following mating, large volumes of fluid (greater than 90 microL) were found in the uterus but, from days 2 to 5, only 2-5 microL of fluid were present. The ratio of sodium to potassium fell from 4.5:1 on day 1 to 1.8:1 on days 2 to 5 of pseudopregnancy, indicating that uterine fluid in the mouse has a high K+ content ranging from 35 mEq L-1 on day 1 to 75 mEq L-1 on day 5. Glucose, lactate and pyruvate in uterine flushings were also assayed and their concentration in uterine fluid calculated using the volumes found above. The level of all substrates was low on day 1 after mating. From day 2 onwards approximately 1 mM glucose was present in the fluids. The concentration of lactate was more variable, and peaked at 4 mM on day 2 of pseudopregnancy. In general, the concentration of pyruvate was 10% of the lactate value.

Animals↗
PubMed1988

The relative chance of pregnancy following tubal or uterine transfer procedures.

In a 7-month study period, a total of 113 pregnancies were generated in 380 women (30%) undergoing transfers in one of four assisted conception procedures: gamete intrafallopian transfer (GIFT), pronuclear stage tubal transfer (PROST), tubal embryo stage transfer (TEST), and in vitro fertilization and embryo transfer (IVF-ET). It was shown that both the pregnancy rate per transfer procedure and the number of pregnancy sacs arising per embryo transferred were significantly higher among the groups having tubal transfer (P less than 0.001). There were no significant differences in the pregnancy or implantation rates among the three groups having tubal transfer procedures when the GIFT results were adjusted for a 72% fertilization rate noted in the combined IVF-ET and PROST groups. Early pregnancy wastage showed a similar pattern among the four groups and, overall, 67% of pregnancies advanced beyond 20 weeks.

Adult↗
PubMed1988

Preliminary results using pentoxifylline in a pronuclear stage tubal transfer (PROST) program for severe male factor infertility.

In vitro trials with washed spermatozoa incubated in medium containing 1 mg/ml of the methyl xanthine phosphodiesterase inhibitor PF showed improved counts of total motile and total progressively motile spermatozoa in cases of oligospermia/asthenospermia. Application of this agent in a PROST program for a series of nine couples presenting for treatment with histories of failed fertilization in vitro resulted in five pregnancies (four singleton, one triplet) and the subsequent delivery of normal infants. The results warrant further evaluation of this sperm treatment for cases of severe male factor infertility.

Embryo Transfer↗
PubMed1988

Methods of water purification for the preparation of culture media in an IVF-ET programme.

Five methods of water purification for culture media preparation have been described. The quality of media thus prepared has been assessed retrospectively by relating to the fertilization and pregnancy rates of a total of 646 treatment cycles in an in-vitro fertilization and embryo transfer (IVF-ET) programme. All media for human use was subjected to quality control assessment in a mouse embryo culture system. Although no differences were seen in the fertilization rates or the proportion of women proceeding to embryo transfer, significant differences were seen in the pregnancy rates. The highest pregnancy rates were obtained using rainwater distilled six times (22/100, 22%) or eight times (40/184, 21.7%), and water polished using a Milli-Q water purifying system (41/181, 22.7%). Significantly lower pregnancy rates were obtained when the water was purified using an alternative Milli-Q system (9/89, 10.1%) or dam water distilled six times (6/63, 9.5%). These findings may reflect contamination of local dam water supplies but demonstrate the difficulty in purifying water for the preparation of culture medium.

Culture Media↗
PubMed1988

The treatment of normospermic infertility by gamete intrafallopian transfer (GIFT).

Gamete intrafallopian transfer (GIFT) was applied in 207 treatment cycles in 73 couples. The pregnancy rate in cycles with only one (2/21, 9.5%) or two (2/29, 6.9%) oocytes transferred was significantly less than that in which four oocytes (36/116, 31.0%) were replaced. The collection of more than four oocytes did not influence the pregnancy rate in that treatment cycle. The overall pregnancy rate was 24.2% (50 of 207) and was similar in the four infertility groups studied (non-occlusive tubal disorders, endometriosis, cervical factor and unexplained infertility) with 28 (56%) of the pregnancies delivered at greater than or equal to 20 weeks. The pregnancy wastage included 4 (8%) ectopic pregnancies and 3 (6%) late pregnancy losses. The 12 multiple pregnancies occurred following the transfer of three and four oocytes.

Fallopian Tubes↗
PubMed1987

Human follicular fluid levels of calcium, copper and zinc.

Human follicular fluid was collected under laparoscopic vision from 33 follicles in patients stimulated with clomiphene-human menopausal gonadotrophin in an IVF programme. Thirty-one oocytes were obtained from 26 follicles from which clear follicular fluid was obtained, and 16 oocytes fertilized and cleaved. The follicular fluid was analysed for calcium, copper and zinc using atomic absorption spectroscopy. The mean levels of calcium, copper and zinc were 86.9 +/- 11.6, 1.16 +/- 0.29, and 0.72 +/- 0.12 micrograms/ml, respectively. Their levels were not significantly different in the follicular fluid collected from follicles of different sizes, with or without oocyte, and follicles with oocytes that were fertilized and were unable to be fertilized. Therefore, the concentrations of these elements do not seem to reflect oocyte status or maturity.

Calcium↗
PubMed1986

Superovulation of mice with human menopausal gonadotropin or pure follicle-stimulating hormone in combination with human chorionic gonadotropin and the effects of oocyte aging on in vitro fertilization.

The response of female mice of F1 hybrids (CBA x C57/BL) to superovulatory doses of human menopausal gonadotropin (hMG) or pure follicle-stimulating hormone (FSH) in combination with human chorionic gonadotropin (hCG) was studied. Furthermore, the effect of oocyte aging in vivo on the subsequent rate of fertilization in vitro was also investigated. The oocytes were collected at 12, 18, and 24 hr after hCG injection and in vitro fertilization (IVF) was carried out in T6 medium. A higher proportion of animals responded to hMG stimulation (32/70) compared to pure FSH (15/66). Furthermore, hMG gave a higher oocyte recovery (454/32) than pure FSH (77/15). Fertilization rates of 57.8, 51.5, and 53.5% were obtained for the 12-, 18-, and 24-hr groups, respectively, after correction for parthenogenetic division of oocytes in the controls. No significant differences in fertilization rates were observed among the three time intervals used in recovering oocytes. However, as the degeneration and parthenogenetic division increased with the delay in collection of oocytes, 12 hr post-hCG injection was the best time to collect oocytes to obtain optimum results in in vitro fertilization.

Animals↗
PubMed1985

Follicular-phase response in two clomiphene-human menopausal gonadotropin regimes for an in vitro fertilization program.

Two clomiphene-human menopausal gonadotropin regimes were assessed for our in vitro fertilization and embryo replacement (IVF and ER) program since September 1983. Clomiphene, 50 mg bd, was taken from day 2 for 5 days. Human menopausal gonadotropin (hMG) was given from day 6; for the first regime, 75 IU/day was given for the first 3 days, and for the second, 150 IU/day. The subsequent dosages were dependent on the estradiol response. There were 9 cases for the first regime and 10 cases for the second. The mean number of hMG ampoules given was 16.5 and 19.25, respectively. The number of follicles seen on ultrasound was 3.0 +/- 0.5 and 3.4 +/- 1.2 (mean +/- SD), respectively. There was no statistical difference in the estradiol response up to the day of laparoscopic ova recovery for the two regimes. However, a spontaneous luteinizing hormone (LH) surge was observed in 4 of 9 cases in the first group and 6 of 10 cases in the second group. When a comparison was made between cases that had a spontaneous LH surge and cases that were given human chorionic gonadotropin (hCG), there was a higher estradiol level on the day of the laparoscopy in the hCG group with the lower hMG regime (P less than 0.05). There were no other differences. Our small series shows a 52.6% incidence of spontaneous LH surge with clomiphene-hMG. Hence such stimulated regimes can result in a high proportion of spontaneous LH surges; this may be an index of satisfactory endocrinological control in spite of an increase in the number of follicles.

Clomiphene↗
PubMed1985

Influence of environmental factors on the metabolism of glucose by preimplantation mouse embryos in vitro.

The metabolism of glucose by late preimplantation mouse embryos was studied in a variety of media whose composition had been changed to reflect the environmental conditions in the uterus more closely than do standard culture media. The effects of combinations of energy substrates, the presence or absence of amino acids and the level of potassium in the medium were investigated. The use of energy substrates for in vitro culture at levels present in the uterine environment resulted in rates of synthesis and degradation of glycogen pools similar to those obtained using standard in vitro culture conditions but elevated incorporation into non-glycogen macromolecules. Amino acids influenced the metabolism of glucose by limiting the entry of glucose carbon into the non-glycogen macromolecular pool and directing more glucose into the synthesis of acid-soluble glycogen. Increasing the K+ concentration to 60 mM in the culture medium caused a small but significant increase in the number of eight-cell embryos degenerating during culture for 24 h but the metabolism of glucose was unaffected over this time. At the time of morula transformation to the blastocyst this level of potassium ions suppressed glycogen synthesis by 50% over 5 h but did not affect its turnover during chase culture. It is concluded that factors other than those studied here contribute to the maintenance of the low glycogen levels found in uterine embryos.

Amino Acids↗
PubMed1985

Metabolism of glucose by preimplantation mouse embryos in the presence of glucagon, insulin, epinephrine, cAMP, theophylline and caffeine.

Neither insulin nor epinephrine influenced the incorporation of glucose into the acid-soluble or acid-insoluble glycogen pool of mouse embryos at the morula-early blastocyst stage during 5 h culture in the presence of radiolabelled glucose. During a 5 h chase culture of pulse-labelled embryos at this stage of development, acid-soluble glycogen labelled during the pulse was not utilized by the embryo but acid-insoluble glycogen was reduced. Addition of glucagon, insulin, epinephrine, cAMP, theophylline or caffeine during chase culture had no effect on the turnover of label in the glycogen pools of the embryo. These results indicate that the turnover of embryonic glycogen observed in vivo is not due to the direct effect of the hormones that regulate glycogen metabolism in the mother. Insulin was found to stimulate incorporation of glucose into non-glycogen macromolecules during both pulse and chase culture. Thus, whilst an effect of insulin on glycogen metabolism was absent, the anabolic effects of this hormone appear to have been expressed in the embryo at this stage of development.

Animals↗
PubMed1985

The origin and distribution of cortical granules in human oocytes with reference to Golgi, nucleolar, and microfilament activity.

The origin and distribution of cortical granules were investigated in human preovulatory oocytes at various phases of maturation. Twenty-five oocytes obtained from unstimulated small antral follicles and from stimulated large antral and mature follicles were examined by transmission electron microscopy. Ovarian stimulation in women was accomplished by administering Clomid followed by hMG or hCG or both. Small antral follicle oocytes were dissected from ovarian biopsies, while the other oocytes were recovered by laparoscopy. Some oocytes were allowed to mature in Ham's F-10 or Whittingham's T-6 media before routine fixation in glutaraldehyde/osmium. Cortical granules originate from typical, hypertrophic Golgi complexes during early maturation and continue till its completion. Evidently there are two waves of cortical granule synthesis, the first more prolific than the second. The first occurred in small antral follicle oocytes, when there was a peak in Golgi activity, and the second was observed at the germinal vesicle stage, particularly at the onset of resumption of meiosis. Golgi complexes became progressively scarce as oocytes completed first maturation. Golgi membranes were also involved in the formation of lysosomes. A well-defined band of microfilaments was detected in small antral follicle oocytes which seemed to prevent the cortical granules, organized in a single layer, from migrating to the periphery. This band gradually became disorganized at the germinal vesicle stage as oocytes resumed meiosis, when cortical granules were apparently migrating to the surface. Metaphase I and mature oocytes had one to three discontinuous layers of cortical granules beneath the oolemma. The general organization of oocytes was also investigated and the roles of the nucleolus and endoplasmic reticulum in relation to Golgi activity and cell secretion were discussed.

Cell Nucleolus↗
PubMed1984

Synthesis and degradation of labelled glycogen pools in preimplantation mouse embryos during short periods of in vitro culture.

The incorporation and turnover of glucose carbon by mouse embryos during short periods of in vitro culture were studied using [U-14C]glucose as marker. Particular attention was given to the synthesis and degradation of the acid-soluble and acid-insoluble glycogen pools. During a 5-h culture period, incorporation into all fractions isolated increased during development from the 1-cell to the early blastocyst stage. During maturation of the blastocyst, incorporation into acid-insoluble glycogen fell whilst that into acid-soluble glycogen continued to rise linearly over this 24 h period. At the late blastocyst stage over 80% of total glucose carbon accumulated was in this latter fraction. The decrease in acid-insoluble glycogen observed above was found to occur as a sudden change between 96 and 104 h post-hCG. The turnover of glucose carbon incorporated into the glycogen pools was studied using pulse-chase culture techniques. The results indicate that the considerable amounts of glycogen accumulated at the later stages of preimplantation development cannot act as a major energy source in vitro except in the absence of energy substrates. Under these conditions of energy starvation, however, the breakdown of acid-insoluble glycogen is inhibited. The findings show that the late preimplantation embryo accumulates large amounts of acid-soluble glycogen in vitro due to increased rate of synthesis and low rate of degradation. It is suggested that the falling levels of glycogen reported in the uterine embryo are most likely a result of environment factors other than the availability of energy substrates.

Animals↗