In an article in PLoS Medicine, Gert Meijer (University Medical Centre Utrecht, The Netherlands) and colleagues discuss what kind of progress there has been in restoring the function of diseased or damaged bone by bone tissue regeneration.

The life cycles of many viruses include a self-assembly stage in which a powerful molecular motor must pack the DNA genome into the virus's preformed shell (the capsid). How it manages this intricate feat has been subject to debate, but we know that the DNA passes into the capsid shell through a channel formed by a structure called the connector. Scientists have speculated that rotation of the connector complex might feed the DNA into the capsid as it turns.

How does the heart attain its characteristic shape? Shape may be sculpted by cell movement, cell division, or changes in cell size and shape, all of which can be influenced by the local environment. The heart appears as a simple tube early in development; later, the tube walls bulge outward to form the cardiac chambers.

By first probing the way primitive yeast make cholesterol, a team of scientists has discovered a long-sought protein whose human counterpart controls cholesterol production and potentially drug metabolism.

A test for the two strains of human papillomavirus responsible for most cervical cancers is under study.

Studying DNA obtained from teeth of ancient cave bears, researchers have been able to identify a shift in a particular population of the bears inhabiting a European valley in the late Pleistocene era. The findings illustrate the ability of DNA sequence analysis to reveal aspects of animal population dynamics in the distant past and potentially illuminate the influence of human migrations in animal population changes. The new work, reported by a collaborative group of researchers including Michael Hofreiter of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, appears in the February 20th issue of the journal Current Biology, published by Cell Press.

A newly released study suggests that the majority of cases of drug-resistant tuberculosis (TB) among patients undergoing treatment for the disease may be due to new infections, not acquired resistance. If confirmed in future studies the research, in the March 15 issue of The Journal of Infectious Diseases, may drive a major shift in strategy for controlling TB.

A promising approach to gene therapy involves short DNA fragments (interfering RNA) that bind to specific genes and block their "translation" into the corresponding, disease-related protein. A stumbling block has been the efficient and targeted delivery of RNA into the cells. Researchers led by Hongjie Dai at Stanford University have chosen to use carbon nanotubes as their "means of transport".

As evidence mounts that the body's normally protective inflammation response can drive some precancerous tissues to become fully malignant, UCSF scientists report discovering an apparent trigger to this potentially deadly process.

Three years ago Mark Kay, MD, PhD, published the first results showing that a biological phenomenon called RNA interference could be an effective gene therapy technique. Since then he has used RNAi gene therapy to effectively shut down the viruses that cause hepatitis and HIV in mice.

Many commercially prized fish from the depths of the world's oceans are severely threatened by over-fishing and the species' ability to recover is constrained by the fishes' long lifespans and low reproductive success, a panel of experts said today at the annual meeting of the American Association of the Advancement of Science. Some of the fish species living at depths greater than 500 meters take decades to reach breeding maturity, so there are no quick-fix remedies available to replenish the population, said Selina Heppell, a fisheries biologist from Oregon State University.

An international team of researchers from 19 countries has identified one gene and a previously unidentified region of another chromosome as the location of another gene that may contribute to a child's chances of having autism.