Higher concentrations of melanin - the color pigment in skin and hair - may be placing darker pigmented smokers at increased susceptibility to nicotine dependence and tobacco-related carcinogens than lighter skinned smokers, according to scientists.

A two-year study conducted by researchers at George Mason University, INOVA Fairfax Hospital and the National Cancer Institute may open the door to new therapies for combating chronic diseases associated with obesity, a condition that affected more than 33 percent of American adults in 2005-06 according to the Centers for Disease Control and Prevention.

The production of melanin gives us sunburns, but it also helps invertebrate animals to encapsulate attacking fungi and parasites. Uppsala University researchers, in collaboration with Korean and Thai colleagues, can now show that melanin also protects against bacterial infections, at least in crayfish. The study is published in the latest Net edition of Journal of Biological Chemistry.

In an early step toward nonsurgical screening for malignant skin cancers, Duke University chemists have demonstrated a laser-based system that can capture three-dimensional images of the chemical and structural changes under way beneath the surface of human skin.