Semen is the main vector for HIV-1 dissemination worldwide. It contains three major sources of infectious virus: free virions, infected leukocytes, and spermatozoa-associated virions. We focused on the interaction of HIV-1 with human spermatozoa and dendritic cells (DCs). We report that heparan sulfate is expressed in spermatozoa and plays an important role in the capture of HIV-1. Spermatozoa-attached virus is efficiently transmitted to DCs, macrophages, and T cells. Interaction of spermatozoa with DCs not only leads to the transmission of HIV-1 and the internalization of the spermatozoa but also results in the phenotypic maturation of DCs and the production of IL-10 but not IL-12p70. At low values of extracellular pH (∼6.5 pH units), similar to those found in the vaginal mucosa after sexual intercourse, the binding of HIV-1 to the spermatozoa and the consequent transmission of HIV-1 to DCs were strongly enhanced. Our observations support the notion that far from being a passive carrier, spermatozoa acting in concert with DCs might affect the early course of sexual transmission of HIV-1 infection.

To the best of our knowledge, these are the first pregnancies and normal births using oocytes that were cryopreserved in a choline-based medium. The small sample size prevents us from concluding that freezing in a low-sodium medium is superior to using a conventional one.

We report five cases in which no oocytes were retrieved after standard ovarian stimulation for in-vitro fertilization (IVF), and in which it was found that mistakes had been made at the time of human chorionic gonadotrophin (HCG) administration. In all five cases, oocyte retrieval was achieved after injecting HCG, when necessary, and reprogramming aspiration 24-36 h later. A mean of 7+/-3.2 MII oocytes were recovered per patient and 3.2+/-0.8 embryos were transferred. Three clinical pregnancies were obtained, and four healthy infants were born. In our programme, these were the only cases of empty follicle syndrome (EFS) that appeared over a total of 1118 cycles, and were all explained by human error in the administration of HCG. Our experience shows that human error could be considered a significant factor in the aetiology of empty follicle syndrome, and that EFS may be in part avoided by taking simple preventive measures.

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