Doctors have long wondered why, in some people, the immune system turns against parts of the body it is designed to protect, leading to autoimmune disease. Now, researchers at the National Institutes of Health's (NIH) National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), in collaboration with the Oklahoma Medical Research Foundation, have provided some new clues into one likely factor: the early development of immune system cells called B cells.

An international team of scientists has discovered that the ubiquitous bacteria that causes most painful stomach ulcers has been present in the human digestive system since modern man migrated from Africa over 60,000 years ago. The research, published online today (7 February) by the journal Nature, not only furthers our understanding of a disease causing bacteria but also offers a new way to study the migration and diversification of early humans.

Marijuana-like chemicals in the brain may point to a treatment for the debilitating condition of Parkinson's disease. In a study to be published in the Feb. 8 issue of Nature, researchers from the Stanford University School of Medicine report that endocannabinoids, naturally occurring chemicals found in the brain that are similar to the active compounds in marijuana and hashish, helped trigger a dramatic improvement in mice with a condition similar to Parkinson's.

Researchers report discovering the receptor through which a group of life-threatening hemorrhagic fever viruses enter and attack the body's cells, and show that infection can be inhibited by blocking this receptor. The findings, to be published online by the journal Nature on February 7, give a clue to the high lethality of New World arenaviruses, suggest a way of reducing the severity of infection, and point the way toward a sorely needed treatment strategy.

Just a few whiffs of a chemical found in male sweat is enough to raise levels of the stress hormone cortisol in heterosexual women, according to a new study by University of California, Berkeley, scientists.

The first draft of the horse genome sequence has been deposited in public databases and is freely available for use by biomedical and veterinary researchers around the globe, leaders of the international Horse Genome Sequencing Project announced today.

Using a unique weaving machine of their design, Duke University Medical Center researchers have created a three-dimensional fabric "scaffold" that could greatly improve the ability of physicians to repair damaged joints with the patient's own stem cells.