SKIN CELLS INTO STEM CELLS
In a pair of landmark studies, two groups of scientists announced in November that they have reprogrammed human skin cells to act like embryonic stem cells, whose potential to mature into any other kind of cell in the body ultimately may prove key to curing a number of diseases. For instance, diabetes occurs when pancreas cells that produce insulin are damaged or die. If those cells could be replaced by healthy cells, the disease might be cured. The two separate research teams were from Japan and the University of Wisconsin. Their discoveries raise the prospect that stem cells from human embryos might no longer be needed - thereby avoiding thorny ethical and theological concerns. The research was published in the journal Cell and the journal Science.
I CAN SEE CLEARLY NOW
This work is still in the early stages, but researchers at Harvard Medical School are working to restore sight in congenitally blind people by placing an implant in the brain. The implant translates images from a digital camera into neural impulses and then feeds that information into the visual system. Viola! Now the blind can see. The Harvard researchers are focusing on the lateral geniculate nucleus (LGN), a relay station on the route from the optic nerve to the visual cortex, a hard-to-reach and previously ignored part of the vision system.
SYNTHETIC SKIN
Burn victims may soon have more options. Several universities and research labs are trying to develop artifi cial skin that breathes and sweats, unlike the skin substitute now used for people with severe burns. Harvard Medical School is using a growth factor to draw stem cells in a patient's own blood to the wound. This would improve the artificial skin's resistance to infection. Preliminary studies done on mice demonstrated a faster healing time and the animals appeared to have regenerated new tissue. At the Shriners Children's Hospital in Connecticut, scientists engineered bacteria resistant skin cells in a lab and are testing them on animals.
They hope to produce a skin that will sweat, tan and fi ght off
infection. These test-tube grown, genetically modifi ed skin
cells produce a higher level of a needed antibacterial protein.
THE TINY HAND THAT HEALS
With an opposing finger and thumb and extreme range of motion, a tiny micro-hand may one day be used for microsurgery. Chang-Jin Kim, a lead researcher at the University of California, Los Angeles, developed the experimental surgical implement. It is less than one millimeter wide and can clutch and release a fi sh egg under water or on dry land. The "hand" consists of four finger-like projections with polymer balloons doing the work of the "muscles" at the joints. The tiny grasper uses micro-electromechanical systems to mimic the human hand, only on a micro-scale, making surgeries less invasive.
INCISORS, MOLARS AND CANINES, OH MY!
What if you never needed dentures or dental implants? How cool would it be if they found a way to grow new teeth? Well, they have. Takashi Tsuji, an associate professor from the Tokyo University of Science, led a Japanese team that regrew a tooth from cells extracted from mouse embryos. The researchers then transplanted the new tooth into an adult mouse and the tooth continued to grow to full size. Mice teeth form during embryonic development, as do human teeth. Using multiple mouse embryos, the team isolated two major cell types that form teeth, epithelial and mesenchymal, and transferred them to a collagen gel culture, where the cells interacted to form a tooth bud. The bud was transferred to the liver of an adult mouse, where the increased blood supply proved fertile tooth-growing ground. Takashi then inserted the tooth into the mouse's mouth where it grew to full size. Meanwhile, Paul Sharpe, head of the Craniofacial Development Department at King's College in London, saw success using bone-marrow stem cells, forming teeth and transplanting them into adult mouse cavities. In the next three years, Sharpe hopes to identify other stem cells able to form not only teeth, but roots.
