In the October 1 issue of G&D, Dr. Guillermo Oliver (St. Jude Children’s Research Hospital) and colleagues present new evidence to resolve a century-old debate over the origin of the mammalian lymphatic vasculature. Understanding the development of the lymphatic vasculature is integral to understanding its function in both health (mediating immunity and maintaining tissue fluid levels) and disease (lymphedema and spreading tumor metastasis).

Researchers at the Partners AIDS Research Center at Massachusetts General Hospital (PARC-MGH) may have discovered a second molecular “switch” responsible for turning off the immune system’s response against HIV. Last year members of the same team identified a molecule called PD-1 that suppresses the activity of HIV-specific CD8 T cells that should destroy virus-infected cells. Now the researchers describe how a regulatory protein called CTLA-4 inhibits the action of HIV-specific CD4 T cells that control the overall response against the virus. The report will appear in the journal Nature Immunology and is receiving early online release.

Pills, sponges, IUDs, diaphragms-- women have many options for planning their fertility, none of them quite perfect. But what if men want to help out? They have only two options -- vasectomy, which is usually permanent, and condoms, which are crucial for dating but get old in long-term relationships. Will men ever have a way to reliably make sure that nobody is every calling them "Daddy" before they are ready?

As policy makers debate what levels of ozone in the air are safe for humans to breathe, studies in mice are revealing that the inhaled pollutant impairs the body’s first line of defense, making it more susceptible to subsequent foreign invaders, such as bacteria.