IFFS expert group report on the Whittemore study related to the risk of ovarian cancer associated with the use of infertility agents.
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Age Factors↗
Biomedical subjects
B Tarlatzis
Publications and source records attributed to B Tarlatzis.
Preimplantation diagnosis.
Although healthy babies have been born after preimplantation diagnosis for sex determination, this technique is still in an experimental phase. To date, removal by micromanipulation of one or two blastomeres from an eight-cell embryo seems an acceptable procedure. Since a reasonable number of biopsied embryos will implant and develop in utero, the methodology for the analysis of the blastomeres at the chromosomal, gene product or DNA level, needs to be improved before further clinical application. In the meanwhile, more information about early embryo development will become available.
Animals↗
Beta-N-acetylhexosaminidase activity in human oocytes and preimplantation embryos.
beta-N-acetylhexosaminidase is a lysosomal enzyme, which has two isoenzymes: beta-Hex A, a trimer consisting of one alpha-chain and two beta-chains (alpha beta 2) and beta-Hex B, a tetramer formed of four beta-chains (beta 2 beta 2). Genetic defects in the alpha-chain lead to Tay-Sachs disease, whereas mutations in the beta-chain gene lead to Sandhoff disease. In a previous study we developed a microassay for total beta-N-acetylhexosaminidase and used this for measuring activities in mouse oocytes and preimplantation embryos. In this study, to assess the feasibility of transferring this technique to the human for the purposes of preimplantation diagnosis for Tay-Sachs and Sandhoff disease, beta-Hex activity was assayed in human oocytes and embryos and in the medium in which they had been cultured. We showed that although the activity of beta-N-acetylhexosaminidase in human oocytes and embryos was > 500 times higher than in the mouse, it was not detectable in the culture medium and the activity in oocytes and embryos remained virtually constant throughout human preimplantation development, making it difficult to distinguish embryonic from maternal enzyme activity. In the absence of this distinction it would be inappropriate to use beta-N-acetylhexosaminidase activity for the purposes of preimplantation diagnosis of Sandhoff or Tay-Sachs disease. These experiments demonstrate that measuring the beta-N-acetylhexosaminidase activity in human embryos cannot be used at present for preimplantation diagnosis.
Blastocyst↗
Human chorionic gonadotropin stimulation of estradiol production and androgen antagonism of gonadotropin-stimulated responses in cultured human granulosa-luteal cells.
Baseline and gonadotropin-stimulated estradiol production were examined in long term cultures of human granulosa-luteal cells isolated from women undergoing in vitro fertilization. Estradiol production declined by 70% during the first 48 h in culture and was minimally stimulated by the addition of hCG to the culture medium. During subsequent culture from 48-120 h estradiol production was significantly increased over control levels by hCG concentrations greater than 0.1 IU/ml. Incubation with testosterone stimulated estradiol production 100-fold in the presence and absence of gonadotropin. hCG (0.01-10 IU/ml) stimulated a 3- to 13-fold increase in progesterone production. However, at hCG concentrations greater than 1 IU/ml, coincubation with testosterone (10(-7) M) significantly inhibited progesterone production. Dihydrotestosterone also inhibited progesterone production, but to a lesser extent than testosterone. Freshly isolated granulosa-luteal cells specifically bound small amounts of [125I]hCG (less than 1,000 cpm/10(5) cells). Glycine buffer wash was shown to reversibly remove more than 88% of bound hCG and, in freshly isolated cells, increased [125I]hCG binding by 100%. In 5-day cultures, specific [125I] hCG binding nearly doubled from 52,000 cpm/10(5) cells in control cultures to 87,000 cpm/10(5) cells in cultures treated with hCG (0-5 IU/ml). At the highest concentration of hCG (5 IU/ml), testosterone (10(-7) M) significantly inhibited the amount of [125I]hCG specifically bound. In summary, estradiol production in long term cultures of granulosa-luteal cells appears to be gonadotropin dependent. In addition, the presence of testosterone (10(-7) M) antagonizes hCG-stimulated progesterone and LH receptor production by these cells.
Androgens↗
Psychological interviews in screening couples undergoing in vitro fertilization.
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Attitude to Health↗
The periovulatory and luteal phase of conception cycles following in vitro fertilization and embryo transfer.
The pattern of periovulatory and luteal phase levels of serum estradiol (E2) and progesterone (P) were compared between 8 conception and 28 nonconception cycles of patients undergoing in vitro fertilization (IVF). Ten additional women served as control subjects and did not undergo follicular aspiration. Follicle growth was induced with an individualized Pergonal (human menopausal gonadotropin) regimen, and laparoscopy was performed 36 hours after human chorionic gonadotropin administration. The length of the luteal phase did not differ significantly among the three groups and was between 14 and 15 days in duration. When IVF conception cycles were compared with nonconception cycles, although no difference in the number of large follicles was observed (4.25 +/- 0.45 versus 3.6 +/- 0.25), the patterns of E2 and P differed significantly. Daily serum E2 levels tended to be higher in the periovulatory phase in conception cycles when compared with nonconception cycles, and were significantly (P less than 0.05) higher in the early, mid, and late luteal phases. Serum P levels were significantly higher (P less than 0.05) in conception cycles from the midluteal phase onward. A decline in both serum E2 and P in the midluteal phase in conception cycles suggested some degree of corpus luteum deficiency. It is suggested that high E2 levels in the periovulatory phase may be an indicator of better follicular development under human menopausal gonadotropin stimulation and that the deficiency observed in the late luteal phase is overcome with the establishment of pregnancy.
Adult↗
Improved techniques for collecting motile spermatozoa from human semen. I. A self-migratory method.
A simple apparatus to collect moving sperm by non-traumatic means which can be used for artificial insemination is described. The technique is based on enhancing the process of migration from the seminal fluid into a top-layered artificial medium in an ordinary test tube. This has been achieved by controlling 3 main variables: 1) The dilution of migrated sperm was minimize by using only 0.5 ml of the medium layered onto 1 ml semen; 2) increasing the surface area between these media by turning the test tube from a vertical to almost a horizontal position; 3) stimulating sperm activity by incubation at 37 degrees C under air: 5% CO2 for 30 min. When restored to a vertical position approximately 0.3 ml medium, sufficient for most AIH or IVF procedures, was gently aspirated. The effects of these variables on the rate of sperm migration was tested one at a time, and increments that ranged from 20% to as much as 10-fold were detected. When these 3 variables were optimized and 58 semen specimens analyzed, it was found that motility increased from 42 to 87%, velocity from 24.5 to 27.3 micron per sec, whilst abnormal forms dropped from 37 to 15%. The final concentration of motile sperm was 23 X 10(6)/ml compared to an original mean concentration of 34 X 10(6)/ml, indicating a relative recovery of 68%. Oligoasthenospermic specimens revealed similar changes in sperm motility, velocity, morphology and recovery. However, due to the low initial content of moving sperm (4.8 X 10(6)/ml), their final concentration was also low (2.7 X 10(6)/ml). Such specimens required additional preliminary preparation to increase the sperm concentration prior to the migratory procedure.
Cell Separation↗
Improved techniques for separating motile spermatozoa from human semen. II. An atraumatic centrifugation method.
A simple and atraumatic method for concentrating washed, motile spermatozoa from normal and subnormal semen specimens is described. It incorporates a modified technique of centrifugation in which sperm are spun onto a soft, fluid cushion, thereby minimizing mechanical damage. Following initial semen dilution to 5-10 ml in an artificial medium, the mixture is transferred to a test tube and layered onto 1 ml of oily contrast medium (Lipiodol). After centrifugation at 300 g for 10 min all but 0.5 ml of the supernatant is discarded, and the unshaken test tube is incubated at 37 degrees C for 15-20 min, during which time the motile sperm migrate into the upper 0.5 ml. After this incubation, 0.3 ml of the upper layer is removed which is sufficient for most IVF and AIH purposes. It contains concentrated, washed, motile spermatozoa that are free of debris and most abnormal forms. No change in pH or osmolarity and no diffusion of any iodine from the oil base into the top layer were detected.
Cell Separation↗
Spontaneous pregnancy following therapeutic approach of an infertile man with aspermia/obstructive azoospermia.
The combination of aspermia and obstructive azoospermia in the same infertile man is a rather rare entity. In the case reported here, all diagnostic criteria as well as subsequent recovery following two operations are compatible with an inflammatory origin. In such cases assisted reproduction should be recommended. However, in this case, an early spontaneous pregnancy rendered this unnecessary.
Adult↗
Seminal plasma transferrin in infertile men.
Seminal plasma transferrin levels were estimated in 51 men with various infertility problems and in 15 fertile subjects. The estimation of transferrin was carried out by using the radial immunodiffusion technique on LC-partigen transferrin plates. The mean value of transferrin decreased (p less than .05) in cases of azoospermia (91 +/- 51 micrograms/ejaculate). No significant difference was found in other sperm quality disorders (asthenoteratospermia = 227 +/- 141, mild OTA = 186 +/- 96, severe OTA = 247 +/- 137 micrograms/ejaculate). The mean value of transferrin decreased (p less than .05) in obstructive azoospermia cases (73 +/- 70 micrograms/ejaculate), whereas in the other causes of infertility no statistical differences were found. Transferrin was correlated with sperm count, sperm volume, and serum LH.
Follicle Stimulating Hormone↗
Azoospermia: clinical, hormonal, and biochemical investigation.
The aim of this study was to evaluate the clinical, hormonal and biochemical characteristics of infertile men with azoospermia. A total of 187 azoospermic out of 2610 infertile men (7.2%) were studied. Mean testicular volume and basal plasma levels of FSH were the most useful parameters concerning the evaluation of azoospermia. Basal plasma levels of LH and T were useful only in azoospermic men with hypogonadism, whereas plasma PRL levels, semen volume, and seminal plasma fructose levels were not found to be of common use except in selected cases.
Follicle Stimulating Hormone↗