Stories tagged RNA

Jun
16
2008

Where are you going?: I'm going home.
Where are you going?: I'm going home.Courtesy Mila
New tests performed on a meteorite found in Australia suggest that life on earth could have had its start in space; it’s possible that the first components of self-replicating genetic material came from outer space.

This particular meteorite only struck Earth about 40 years ago, but new studies confirm that the molecules uracil and xanthine (which are found in our RNA) were present in the meteoritic fragments before human contamination.

Uracil and xanthine are “nucleobases,” and play an important role in the replication of DNA. Some have argued that these molecules could have originally formed on Earth, but these researchers claim that the atmospheric conditions on the planet at the time the first organic molecules are thought to have appeared would have prohibited a terrestrial origin. Going even further, they state that it’s possible—assuming that there are all these vital molecules floating out there on meteors—that life, or at least the key components for life (a big difference I suppose), could be widespread in the universe.

I prefer extraterrestrial life delivery by spaceship, but I guess I’ll take what I can get. Wild.

Jun
27
2007

Have you ever wondered why medicine seems to be so ineffective in dealing with many neurological diseases? We have treatments and drugs to combat disorders throughout the rest of the body, but diseases like Alzheimer’s or Parkinson’s remain difficult to treat.

A team of scientists recently created a drug that can cross the blood-brain barrier to treat neurological diseases in mice. Capillary walls in the brain are very effective at controlling which molecules can pass into the spaces between neurons. This protects the brain from potentially harmful chemicals in the blood. Until now, this also prevented much needed medicines from penetrating into an affected brain!

But, wait. If the brain is so great at preventing molecules from penetrating capillary walls, how do diseases get through? Some viruses, such as rabies, are able to trick the barrier into letting them through. Researches attached one of these trickster molecules from rabies onto a drug, and found that the drug was delivered through the capillary wall and into the brain.

In this study, scientists infected mice with Japanese encephalitis. Medicine delivered using the new method kept 80 percent of diseased mice alive for 30 days, while all of the untreated mice died.

While researchers tested this technique only on mice, soon this could provide huge benefits to humans. The drug used to combat encephalitis in mice uses a kind of RNA, short-interfering RNAs (siRNAs), that block the activity of a gene. This type of RNA can be custom tailored to target almost any disease-causing gene or protein. Combined with the molecules that can break through the blood-brain barrier, scientists could more effectively treat Alzheimer’s, Huntington’s, Parkinson’s and many more neurological diseases.