Contraception for the year 2020

Ethical aspects of reproduction in the next century

Doubtless, the technological advancements achieved in the current century in the area of young women's reproductive health care have also led to the evolution of very important ethical issues that will have to be dealt with in the coming century. Abortion, perhaps the most controversial issue of all, continues to raise a number of ethical issues related to the rights of the women versus the rights of the fetus, which, in addition to the risk of sexually transmitted diseases including the human immunodeficiency virus, emphasize the need for adequate family planning and sexual education. Genetic testing for late-onset diseases, disease susceptibilities, and carrier status may offer medical or psychological benefits; however, several complex ethical, legal, and social issues have been revealed with the advent of this new information. New family structures deviating from the traditional heterosexual couple, consisting of either single or lesbian mothers, have appeared, raising serious disputes regarding the welfare of the child. Important demographic changes are expected in the world population in the 21st century, characterized mainly by a significant increase of the older age groups.

Expression of envelope proteins of endogeneous C-type retrovirus on the surface of mouse and human oocytes at fertilization

Retrovirus genomes express, among other products, the envelop (env) proteins SU (gp70) and TM (p15E). They coexist at the viral surface membrane and are able to promote immunosuppression and membrane fusion. In mouse oocytes, endogeneous retroviruses (ERV) genomes are expressed at fertilization, and antigen epitopes of the Moloney murine leukemia virus (MuLV) env protein gp70 are recognized in the cytoplasm of the oocytes before but not after fertilization. By using a panel of monoclonal antibodies (mAbs) raised against env components, we checked with laser scanning confocal microscopy (LSCM) whether gp70 and p15E were expressed also on the oocyte surface membrane (oolemma). Since we found that both mouse and human unfertilized oocytes expressed these ERV proteins on the oolemma and that the expression enfeebled significantly after fertilization, we assume that ERV genomes could play a role at the sperm-egg binding and fusion.

Capsid protein-encoding genes of hamster polyomavirus and properties of the viral capsid

On the basis of its genome organization the hamster polyomavirus (HaPV) is closely related to the murine polyomavirus Py. But HaPV infection, in contrast to Py infection, gives rise to two different tumor types; depending on the hamster strain used for infection, HaPV induces either epitheliomas or lymphomas. Although the HaPV virions were shown to be similar to those of Py and SV40, more precise information about the structure and protein composition of the HaPV capsid was still missing. Here we describe the primary structure of the capsid protein-encoding HaPV genes and the structure and protein composition of the HaPV capsid. Virions isolated from epitheliomas in HaPV-infected hamsters were shown by electron microscopy to be spherical particles with the typical icosahedral structure of polyomaviruses. However, in contrast to the capsids of SV40 and Py, a T = 7 laevo symmetry of HaPV capsids was observed. Separation of HaPV virions in SDS polyacrylamide gels and Western blotting with VP1-specific antisera identified VP1 as the major capsid protein species corresponding in its molecular weight to the predicted value of 41.8 kDa. Because of the presence of two potential translational initiation sites in the VP1 gene, the N-terminal amino acid sequence of virion VP1 was determined and found to start at the second initiation site. The amino acid homologies of HaPV capsid proteins shared with Py varied between 65.5% (VP1), 45.4% (VP3) and 44.6% (VP2), whereas the homologies to the relevant proteins of other polyomaviruses were found to range between 49.6-57.9% for VP1 and 28.9-41% for VP2/VP3.

Modulation of integrin function inhibits HIV transmission to epithelial cells and fertilization

Integrin-mediated adhesive interactions are viewed in the context of HIV transmission to susceptible cells and fertilization. The ability of a low-molecular-weight non-peptide integrin modulator to inhibit HIV infection (virus-to-cell and cell-to-cell) and sperm-egg fusion is demonstrated. It is concluded that integrin-modulating substances offer significant promise as female-controlled means for preventing sexual transmission of HIV (whatever entity acts as HIV vector in semen and other penile secretions) and as female-controlled contraceptives.