'Lifeless' prion proteins are 'capable of evolution'

Scientists have shown for the first time that "lifeless" prion proteins, devoid of all genetic material, can evolve just like higher forms of life.

The Scripps Research Institute in the US says the prions can change to suit their environment and go on to develop drug resistance.

Prions are associated with 20 different brain diseases in humans and animals.

The scientists say their work suggests new approaches might be necessary to develop therapies for these diseases.

In the study, published in the journal Science, the scientists transferred prion populations from brain cells to other cells in culture and observed the prions that adapted to the new cellular environment out-competed their brain-adapted counterparts.

When returned to the brain cells, the brain-adapted prions again took over the population.

Charles Weissmann, head of Scripps Florida's department of infectology who led the study, said: "On the face of it, you have exactly the same process of mutation and adaptive change in prions as you see in viruses.

READ MORE: http://news.bbc.co.uk/2/hi/health/8435320.stm

Man Receives His Own Stem Cells as a Treatment for Heart Failure

Jul 27, 2009 03:45 PM By Mandy Kendrick in 60-Second Science Blog

The first person to receive a new cardiac stem cell treatment in a U.S. Food and Drug Administration clinical trial is doing well, it was announced last week.

On Friday, doctors at the University of Louisville School of Medicine, in collaboration with the nearby Jewish Hospital, issued a press release stating that one week after treatment, Mike Jones’s heart was getting stronger.

Jones, whose heart tissue is permanently scarred and weakened by two previous heart attacks, suffers from congestive heart failure, a condition affecting about five million Americans each year, according to the National Institutes of Health.

Currently, two treatment options predominate for patients with heart failure, said Mark Slaughter, a cardiovascular surgeon who aided in the trial. A person can receive a heart transplant or a mechanically assisted heart device.

The new approach, using a patient’s adult stem cells to regenerate healthy heart tissue, is currently in phase I clinical trials to test for safety. The procedure consists of removing healthy heart tissue from the patient, purifying the stem cells from the material, and allowing the stem cell population to grow. Once ready, the stem cells are reintroduced into the scarred region of the heart using a minimally invasive technique.

Since the re-injection of his own stem cells on July 17, Jones’s heart has increased its ability to pump blood by about 5 percent. Jones commented in the University of Louisville School of Medicine press release that he felt so good he might “even start jogging again.”

The doctors will continue monitoring Jones every few months for the next two years to measure his recovery. There are currently 13 more patients going through the phase I trial, and the researchers hope to eventually test a total of 20 patients.

Last month, a group at the Cedars-Sinai Heart Institute in Los Angeles made news with a similar technique that was undergoing clinical trials. Instead of using purified stem cells, the group is using a mixture of cells, including stem cells, to regenerate heart tissue. Ken Miles, the first patient to receive the treatment, told CBS’s The Early Show that he “feels great.”

Source: Scientific American