People with HIV have been living longer, healthier lives since the development of highly active antiretroviral therapy (or HAART) in 1995. In fact, most patients on the drug regimen do so well that, according to blood tests, their immune cells appear to return to pre-HIV levels. But two new studies from Rockefeller University and the Aaron Diamond AIDS Research Center (ADARC) show that the immune cells in other body tissues may never rebound, suggesting the need for additional ways to monitor immune system health, and the need for hypervigilance as HIV-positive patients live into their forties, fifties, sixties and beyond. The findings are reported in today's issue of PLoS Medicine and online in the Journal of Virology.

A new study in the December issue of the journal Cell Metabolism, published by Cell Press, offers insight into the manner in which the mammary glands of mammals meet the incredible metabolic demands of milk production. As the normal pathways of breast development undoubtedly affect breast cancer, the findings may have therapeutic implications, the researchers said.

Most of the body’s memory T cells vanish within weeks after a person is infected with the HIV virus. In a study from the Aaron Diamond AIDS Research Center and the Bernard-Nocht Institute appearing in the international open-access journal PLoS Medicine, researchers report that these memory T cells, mostly found in the digestive tract, tend not to return to normal even after years of treatment for HIV.

New research identifies an important gene that influences several aspects of nicotine-induced behaviors in the brain. The study, funded by National Institutes of Drug Abuse, was presented today at the American College of Neuropsychopharmacology's Annual Meeting.

The popular hair-growth drug finasteride, taken by millions of balding men, artificially lowers the results of the prostate-specific antigen (PSA) test, the standard screening test for prostate cancer, a multicenter study has found.

The pattern of active wnt protein (dark blue) follows the development of taste papillae and buds in the tongue of a mouse. Credit: Sarah Millar, University of Pennsylvania School of Medicine; Linda A. Barlow, University of Colorado Health Sciences Center; Nature Genetics Of the five senses, taste is one of the least understood, but now researchers at the University of Pennsylvania School of Medicine have come one step closer to understanding how the sense of taste develops. They have pinpointed a molecular pathway that regulates the development of taste buds. Using genetically engineered mice, they discovered that a signaling pathway activated by small proteins called Wnts is required for initiating taste-bud formation. They have also determined that Wnt proteins are required for hooking up the wiring of taste signals to the brain.

When a newt loses a limb, the limb regrows. What is more, a newt can also completely repair damage to its heart. Scientists at the Max Planck Institute for Heart and Lung Research in Bad Nauheim have now started to decode the cellular mechanisms in this impressive ability to regenerate and have discovered the remarkable plasticity of newt heart cells. As mammals, and therefore also humans, do not have this ability, the findings could contribute to new cell therapies for patients with damaged organs (Journal of Cell Science, 2006).

Scientists have discovered that mutations in a gene known as SOS1 account for many cases of Noonan syndrome (NS), a common childhood genetic disorder which occurs in one in 1,000-2,500 live births. NS is characterized by short stature, facial abnormalities, and learning disabilities, as well as heart problems and predisposition to leukemia.

Transplanted neural stem cells hold promise for reducing the destruction of dopaminergic cells that occurs in Parkinson’s disease and for replacing cells lost to the disease, scientists say.

The popular view is that DNA and genes control everything of importance in biology. The genome rules all of life, it is thought.

Worker bees, wasps, and ants are often considered neuter. But in many species they are females with ovaries, who although unable to mate, can lay unfertilized eggs which turn into males if reared. For some species, such as bumble bees, this is the source of many of the males in the species. But in others, like the honeybee, workers "police" each other – killing eggs laid by workers or confronting egg-laying workers.