Detection and characterization of hepatitis C virus RNA in seminal plasma and spermatozoon fractions of semen from patients attempting medically assisted conception.

To investigate the risk of transmission of hepatitis C virus (HCV) via semen in assisted reproduction techniques, semen samples from 32 men chronically infected with HCV attending a center for assisted procreation were tested for HCV RNA by a reverse transcription-PCR protocol by using a modified version of the Cobas AMPLICOR HCV assay (version 2.0; Roche Diagnostics). The sensitivity of the test was 40 copies/ml.

Apoptosis in preimplantation mammalian embryo and genetics.

The presence of dead cells in the preimplantation mammalian embryo has been well described. Since Kerr et al. (1972), it has become apparent that these cells die by apoptosis, a form of programmed cell death.

Transmission risk of hepatitis C virus in assisted reproductive techniques.

Medical assistance for procreation in a couple where one or both parents has hepatitis C viral infection (HCV) raises the issue of the transmission of the infection to the baby and/or of possible contamination of both the technicians and the gametes or embryos from virus-free parents in the laboratory. It becomes essential to assess transmission risk in assisted reproductive techniques in order to define clearly the management of couples according to their viral status. To define the HCV transmissibility risk in assisted reproduction related to the presence of virus in semen from infected infertile men, HCV RNA detection was performed in sera, and semen and sperm fractions obtained after Percoll gradient centrifugation.

[Apoptosis in the pre-implantation embryo].

It has been well shown that apoptosis occurs in mammalian embryos as early as the blastocyst stage, in order to regulate the importance of the inner cell mass. We have looked for apoptosis at the cleavage stage, in human embryos that could not be transferred because of a high degree of fragmentation (grade IV) or a blockage in embryo development. Most of these embryos had blastomeres with condensed or fragmented chromatin, evocating apoptosis.

Laser scanning confocal imaging of abnormal or arrested human preimplantation embryos.

Purpose: The improved resolution and optical sectioning of a confocal microscope make it an ideal instrument for extracting three-dimensional information, especially from extended biological specimens such as human embryos. The staining of actin together with chromatin allowed us to specify the architecture of the embryo and the appearance of the nucleus.

Methods: F-Actin and chromatin distributions were visualized using laser scanning confocal microscopy in "fresh" and "cryopreserved" human preimplantation embryos obtained by in vitro fertilization.