Human "spare" embryos, judged unsuitable for freezing because of their poor quality, were cocultured for 5 days on a "Vero" cell layer. These epithelial cells were selected because kidney and genital tract have a common embryologic origin and "Vero" cells are a safe and highly controlled cellular support used for vaccine production. In the control group, the embryos were cultured in culture medium alone (B2 + 15% serum). At the end of the culture, the number of blastocysts was significantly higher in the coculture group: 61% vs. 3%. Moreover, at least half of the blastocysts were expanding and hatching (13/25), with a chronologically normal development. These observations suggest that (1) the coculture system improves human embryonic development; (2) it can rescue early degenerating embryos; (3) beneficial effects of coculture are not strictly genital-tract specific, but rather epithelium dependent. This coculture system could be used for in vitro fertilization to prolong in vitro culture and thus make it possible to transfer embryos at a more appropriate time, to eliminate early-blocked eggs, and to freeze embryos at the blastocyst stage, when freezing procedures are most successful.

This paper presents the analysis of 901 cycles of intrauterine artificial insemination with the husband's spermatozoa (AIHIU) in 274 couples who obtained 80 pregnancies. The cumulative pregnancy rate after three cycles of AIHIU was 22% and reached 39% after six cycles. Univariate analysis disclosed two factors of poor prognosis: duration of infertility > 3 years (P = 0.01) and husband's age (P = 0.03). Multivariate analysis revealed that the most significant factor contributing to a decreased likelihood of pregnancy was the age of the husband (P = 0.01), then duration of infertility and dysovulation. The wife's age > or = 35 years did not appear to be of poor prognostic value when taking into consideration the three other factors.

In the present study we describe the localization of proteasomes in human spermatozoa by means of immunolabelling with different monoclonal and polyclonal antibodies detected by confocal microscopy. Western blotting confirmed the specificity of the antibodies and has shown that proteasomes are present in spermatozoa and in seminal fluid. In spermatozoa proteasomes are concentrated in the neck region where the centrioles are located. Some labelling was also detected at the periphery of the head, but no proteasomal antigens were detected in either the nucleus or associated with the flagellum. Proteasome inhibitors did not affect the motility of the spermatozoa, acrosome reaction nor zona binding. It is hypothesized that paternal proteasomes enter the oocyte during fertilization in tight association with the centrioles and may serve a special function during further development which can be associated with the function of a hypothetical proteolysis centre.

Azoospermic semen was obtained from 39 vasectomized men and 93 patients consulting for infertility. The latter underwent bioclinical investigations including measurement of plasma FSH and testicular biopsies. Carnitine content and alpha-glucosidase activity in semen samples were measured. The activity of alpha-glucosidase was determined systematically by a semiquantitative microtechnique and was verified by a spectrophotometric assay. A positive correlation was observed between carnitine and alpha-glucosidase activity. Both parameters were severely diminished in semen from the vasectomized men and the patients suffering from a complete obstruction of the genital tract. Enzyme activity was the most discriminant parameter in terms of sensitivity and specificity. The measurement of alpha-glucosidase in semen is a simple and sensitive method for determining the origin of azoospermia when used in conjunction with assays for plasma FSH.

In 1987, we became aware of the importance of remaining in contact with couples whose embryos had been cryopreserved for > 1 year. As a result, a questionnaire was designed to follow the fate of these embryos. Of 407 couples with cryopreserved embryos, 262 couples opted to use them within 1 year with the intention of fulfilling a parental plan. The remaining 145 couples were questioned by six successive questionnaires sent out between 1987 and 1992. By the end of the study, 336 of the 407 couples (82.5%) had chosen to utilize their embryos in a parental plan. In most cases, the maximum delay of response (5 years according to the Council of State) was respected. The remaining 71 couples (17.5%) either abandoned the parental plan or had not given any information by the end of the study. Initially, anonymous donation to another couple was chosen in preference to destroying the surplus embryos (32 versus 18 couples, P < 0.05). Latterly, however, these differences have balanced out (24 versus 28, not significant). Only those couples who initially opted to donate embryos to another couple changed their attitude in later years. In the long run, 62 couples decided not to pursue their parental plan; of these, 24 couples chose to make a gift to another couple, 28 couples opted for destruction, and 10 chose to make a gift to research. Nine couples (out of 71) declined to make a decision, but they had all achieved a pregnancy during an in-vitro fertilization (IVF) attempt. Three of these were lost to follow-up, i.e. 0.7% of all couples benefiting from the freezing technique.