Stories tagged Human Organism

Feb
14
2005

Researchers at the University of Michigan have restored the hearing of deaf guinea pigs.

Hair cells in the cochlea of each ear convert sound waves into nerve signals. The cells are easily damaged by loud noises, aging, infections, and certain medications. And, once damaged, hair cells don't grow back. But the researchers used a virus to insert a gene into ear cells that made new cochlear hair cells grow.

During fetal development, the gene makes some cells in the ear into hair cells. In other ear cells, called supporting cells, the gene is inactive. But researchers were able to use the gene to convert existing supporting cells into hair cells.

First, they deafened the guinea pigs by destroying their hair cells with antibiotics. Four days later, they used a virus to insert the corrective gene and get new hair cells to grow. The researchers observed increases in the guinea pigs' brain activity when they exposed them to noises—proof that the new cells are working.

Now researchers are studying whether or not the animals can tell the difference between loud or soft noises, or noises of different frequencies. They're also studying animals deafened in other ways, older animals, and animals deaf for longer periods of time before treatment starts. It will probably be a decade or so before the technique can be tried on human patients.

Feb
08
2005

On February 8, the British government gave a team of scientists permission to clone human embryos for medical research. Legal in the UK since 2001, this is only the second cloning project the government has allowed.

Led by Ian Wilmut, the creator of Dolly the sheep, the team plans to study motor neuron disease, or MND. The disease kills motor neurons—cells in the brain and spinal cord that control movement. MND affects about 350,000 people, and kills 100,000 each year. Wilmut's team wants to study what goes wrong in the afflicted nerve cells.

Feb
04
2005

Researchers at the Mayo Clinic have found a way to use measles to fight cancer.

Viruses are parasites. To reproduce, they seek out sites on a healthy cell, get inside, and then take over the host's cellular machinery. For years, researchers dreamed of using viruses to hijack cancer cells.

The Mayo team knew that measles kills most cancer cells, too. But to use the virus as an anti-cancer treatment, they had to change the virus so it wouldn't attack healthy cells. They eliminated the virus's ability to bind to its natural receptors, and retargeted it to zero in on ovarian cancer cells.

In lab animals implanted with human cancer cells, the virus hunted down and destroyed only infected cells. Clinical trials on patients with ovarian cancer began last summer, but it will be at least three years before the treatment is approved for use in hospitals.