Dual fluorescent in situ hybridisation for simultaneous detection of X and Y chromosome-specific probes for the sexing of human preimplantation embryonic nuclei.

Dual fluorescent in situ hybridisation has been used for the simultaneous detection of X and Y chromosome-specific probes in single cleavage nuclei from disaggregated 4- to 7-cell human embryos. Based on the presence of a Y signal or 2 X signals in the absence of a Y, 89% of poor quality metaphases and 72% of interphase nuclei could be classified as male or female. With further refinements, this technique will offer a credible alternative to the polymerase chain reaction for the diagnosis of sex in human preimplantation embryos in families segregating for X-linked genetic disease.

Resources for infertility treatment.

Infertility is common, a serious medical problem in both advanced and underdeveloped countries. At present, medical resources are often used very haphazardly and frequently extravagantly to combat fertility problems. Whilst it seems very unlikely that society will be able to prevent infertility effectively, there is no doubt that the resources available could be better organized for greater benefit.

Beneficial effects of a 24 h delay in human chorionic gonadotrophin administration during in-vitro fertilization treatment cycles.

We used a gonadotrophin-releasing hormone agonist (buserelin) and human menopausal gonadotrophin (HMG) for superovulation for in-vitro fertilization (IVF) in 143 patients. The patients were prospectively allocated to two balanced groups. In one group (47 patients) human chorionic gonadotrophin (HCG) was given when the three largest follicles were greater than or equal to 17 mm in diameter, with consistent levels of plasma oestradiol (standard group).

Microsurgical salpingostomy is not an obsolete procedure.

Objective: A review of the results of microsurgery for bilateral distal tubal blockage.

Design: A retrospective review.

Setting: Hammersmith Hospital London and local private hospitals.

Programming in vitro fertilization for a 5- or 3-day week.

Objective: To schedule oocyte retrievals on either 5 or 3 days per week in in vitro fertilization (IVF) cycles.

Design: Human chorionic gonadotropin (hCG) administration was delayed by at least 24 hours in patients undergoing superovulation to avoid egg collections on weekends (group 1). Encouraged by the results, a further prospective study in which oocyte retrievals were programmed for only 3 days a week was undertaken (group 2).

Attitudes towards gamete donation among couples undergoing in vitro fertilization.

The attitudes of 234 anonymous couples undergoing in vitro fertilization toward sperm and oocyte donation were explored by questionnaire. All the questionnaires were returned of which 222 (95%) were complete and analysed. A high proportion of couples found the use of donor sperm acceptable for therapeutic, diagnostic and treatment purposes (77%, 90% and 97% respectively) and 72%, 84% and 90% respectively were willing to donate oocytes for these purposes.

Caveats and suggestions for the ELISA.

This study identifies three categories of errors that may arise from faulty procedures utilized in the ELISA and offers suggestions for their recognition and avoidance. The first deals with the potential sources of 'background' values indicating that the practice of subtracting those values from the total OD measurements of the reactivity of a specific antigen-antibody system is not valid in all instances. A simple method of curve analysis has been devised for determining whether that correction is valid.

Profiles of hypoxanthine guanine phosphoribosyl transferase and adenine phosphoribosyl transferase activities measured in single preimplantation human embryos by high-performance liquid chromatography.

The profiles of hypoxanthine guanine phosphoribosyl transferase (HGPRT) and adenine phosphoribosyl transferase (APRT) activities were examined in normally fertilized human embryos developing at the normal rate in vitro between the 2-4-cell stage on Day 2 and the blastocyst stage on Day 6 after insemination. The activities of both enzymes were assayed simultaneously in extracts of single embryos by measuring the rate of production of the reaction products, inosine monophosphate (IMP) and adenine monophosphate (AMP), separated by high-performance liquid chromatography (HPLC). The activity profiles of the two enzymes over this period showed marked differences.

Fluorescent in-situ hybridization to interphase nuclei of human preimplantation embryos with X and Y chromosome specific probes.

Fluorescent in-situ hybridization (ISH) to interphase nuclei of human preimplantation embryos has been demonstrated with the X and Y chromosome-specific DNA probes, pBamX7 and pHY2.1, respectively. Assigning the sex on the basis of the number of hybridization signals in the majority of nuclei, the efficiencies with both probes to nuclei from male embryos were considerably higher than those previously reported for pHY2.

Inhibition of oestradiol production by epidermal growth factor in human granulosa cells of normal and polycystic ovaries.

Anovulation in women with polycystic ovary syndrome results from a disorder of FSH-mediated follicular maturation which may involve paracrine modulation of FSH action by intra-ovarian factors. Epidermal growth factor (EGF) is a potent inhibitor of FSH-stimulated oestradiol production in the rat and has also been shown to inhibit aromatase activity in human granulosa cells obtained after superovulation. The purpose of this study was to investigate the action of EGF on granulosa cell function in human ovaries which had not been previously exposed to treatment with exogenous gonadotrophins and to compare the responses in tissue obtained from normal and from polycystic ovaries.

Human preimplantation development in vitro is not adversely affected by biopsy at the 8-cell stage.

Normally fertilized human embryos biopsied 3 days after in-vitro fertilization (IVF) have been examined for effects on viability and development in vitro after removal of one or two cells at the 8-cell stage (1/8 and 2/8) from each embryo. A high proportion of 7/8 and 6/8 biopsied and unmanipulated embryos developed to the blastocyst stage between days 5 and 6 (79, 71 and 59%, respectively), and many biopsied embryos (56%) hatched from the zona pellucida in vitro. The viability of biopsied embryos which developed to the blastocyst stage was assessed by daily non-invasive measurement of the uptake of two energy substrates, glucose and pyruvate.

Pregnancies from biopsied human preimplantation embryos sexed by Y-specific DNA amplification.

Over 200 recessive X chromosome-linked diseases, typically affecting only hemizygous males, have been identified. In many of these, prenatal diagnosis is possible by chorion villus sampling (CVS) or amniocentesis, followed by cytogenetic, biochemical or molecular analysis of the cells recovered from the conceptus. In others, the only alternative is to determine the sex of the fetus.

Non-invasive measurement of pyruvate and glucose uptake and lactate production by single human preimplantation embryos.

The consumption of pyruvate and glucose and the production of lactate by 40 single human preimplantation embryos has been measured using a non-invasive technique. Twelve of the embryos showed abnormal fertilization. Of the 28 normally fertilized embryos, nine (32%) developed to the blastocyst stage in culture while the remainder degenerated or arrested during cleavage.

Nine cases of heterotopic pregnancies in 4 years of in vitro fertilization.

The incidence of simultaneous intrauterine and extrauterine pregnancy increased after wider use of ovulation induction and the advent of techniques of assisted reproduction. Nine cases of heterotopic pregnancies are reported after in vitro fertilization (IVF) and embryo transfer (ET) between September 1984 and November 1988. The incidence of heterotopic pregnancies in clinical IVF pregnancies was 9 of 312 (2.