One of the characteristics of embryonic stem cells is their ability to form unusual tumors called teratomas. These tumors, which contain a mixture of cells from a variety of tissues and organs of the body, are typically benign. But they present a major obstacle to the development of human embryonic stem cell therapies that seek to treat a variety of human ailments such as Parkinson's, diabetes, genetic blood disorders and spinal cord injuries.

The mammalian fucose mutarotase enzyme is known to be involved in incorporating the sugar fucose into protein. Female mice that lack the fucose mutarotase (FucM) gene refuse to let males mount them, and will attempt copulation with other female mice. Researchers writing in BioMed Central's open access journal BMC Genetics created the FucM mouse mutants in order to investigate the role of this enzyme in vivo.

UT Southwestern Medical Center researchers have found a compound that preserves newly created brain cells and boosts learning and memory in an animal study.

In a fascinating example of vocal mimicry, researchers from the Wildlife Conservation Society (WCS) and UFAM (Federal University of Amazonas) have documented a wild cat species imitating the call of its intended victim: a small, squirrel-sized monkey known as a pied tamarin. This is the first recorded instance of a wild cat species in the Americas mimicking the calls of its prey.

A specific and remarkably small fragment of RNA appears to protect rats against cocaine addiction—and may also protect humans, according to a recent study funded by the National Institute on Drug Abuse (NIDA), a component of the National Institutes of Health. The study was published today in the journal Nature.

Scientists have discovered two potent human antibodies that can stop more than 90 percent of known global HIV strains from infecting human cells in the laboratory, and have demonstrated how one of these disease-fighting proteins accomplishes this feat. According to the scientists, these antibodies could be used to design improved HIV vaccines, or could be further developed to prevent or treat HIV infection. Moreover, the method used to find these antibodies could be applied to isolate therapeutic antibodies for other infectious diseases as well.