Friday, January 28, 2011

Star Trek in the real world

From the Edmonton Journal:
A team of Vancouver-based scientists have created a hand-held device that will help doctors diagnose sick patients in a quick test that identifies the bugs patients are carrying by separating human DNA from virus DNA.

Finding a virus's DNA from a throat-swab test is similar to "looking for a needle in a haystack," says Andre Marziali, a physics professor at the University of British Columbia, because the sample is crowded with human DNA. He and his team are hoping his medical "tricorder" invention — a portable, battery-powered device that can pinpoint the specific DNA signature of the virus — will help the medical community.

"Researchers often can't identify viruses that are infecting someone because of the amount of human DNA in the background. That is exactly the situation they're in now," Marziali said. "What this can do is it can pick out specific DNA sequences for analysis. This is huge.

"We have an incredible ability to reject background DNA."

Marziali's work was recognized as one of nine UBC advances that will "transform" the world in the university's Next Big Thing in 2011 report. His team is still developing the technology by testing accuracy and speed, but they anticipate the tricorder could be available in as early as three years if they obtain appropriate funding.

The device will have various ways of taking samples from patients — such as blood tests or throat swabs — that can be placed in the main instrument for real-time analysis.

Marziali couldn't suggest a cost estimate for the tricorder, but noted its success depended on being inexpensive because users would need to buy cartridges to hold samples.

The device is developed using the similar technology to the Aurora, a machine used by forensics researchers to extract DNA from the dirtiest of samples, including dirt and tar.

Marziali is president of Boreal Genomics, a company that currently sells the Aurora.

Marziali and his colleague, Lorne Whitehead, co-invented the computer-sized product — which was also used by RCMP to test forensics samples — in 2009. He said the researchers are the first to use electric fields to clean and untangle DNA.

Doctors are about 70 per cent accurate when diagnosing patients during flu season, which is why the tricorder's accuracy would be extremely beneficial, said Dr. Don Low, chief microbiologist at Toronto's Mount Sinai Hospital.

"There's no question it would be useful to the medical community," he said. "It would have an incredible use at the front line as a utility in doctors' offices, walk-in clinics and in the emergency department."

Three influenza strains — including H3N2 — are currently circulating across the country this flu season and Low said symptoms can be extremely similar, making diagnosing and determining appropriate treatments — from bed rest to antibiotics — a challenge.

"If a patient comes in with a sore throat, fever or cough, there's a good likelihood it's influenza. But we don't know if it's influenza A, or influenza B, or if it's one of the viruses circulating. These different kinds of viruses are closely related to each other," Low says.

"It's really empiricism, and only if you're lucky will you get a laboratory test to confirm for deny it," he added, noting that samples taken to a lab could leave doctors waiting up to five days before results are received. "By that point, you've decided how to manage that patient. With 70 per cent sensitivity, you're misdiagnosing."

Low said the device would also help doctors quickly discover if their patients have sexually transmitted diseases or other infections, aside from the common cold or flu.

For his part, Marziali is convinced the device would also be of use in other markets — such as security and pandemic control — and in remote areas where access to doctors and hospitals are limited.
A Medical Tricorder... how cool is that??
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