Adult stem cells originate in a different part of the brain than is commonly believed, and with proper stimulation they can produce new brain cells to replace those lost to disease or injury, a study by UC Irvine scientists has shown.

The chromosomal abnormality that causes a rare, but often fatal, disorder that affects infants has been identified by researchers at the University of California, San Diego School of Medicine, who happened to treat two young children with the disease in San Diego – two of perhaps a dozen children in the entire country diagnosed with the disorder.

CD4+ T lymphocytes, or simply CD4 T cells, are the "brains" of the immune system, coordinating its activity when the body comes under attack. They are also the cells that are attacked by HIV, the devastating virus that causes AIDS and has infected roughly 40 million people worldwide. The virus slowly eats away at CD4 T cells, weakening the immune system.

A new study by researchers at Yale School of Medicine could explain why the cold and flu virus symptoms that are often mild and transient in non-smokers can seriously sicken smokers. Published in the Journal of Clinical Investigation, the study also identified the mechanism by which viruses and cigarette smoke interact to increase lung inflammation and damage.