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Green velvet tarantula is aiding painkiller research

Venoms from spiders and other animals, fine-tuned by evolution to stun and paralyze prey, are an abundant source of painkillers and other drugs. But screening for useful toxins can be an arduous process.

Venoms contain many active toxins, not all of them suitable for use in humans. And once a potentially effective toxin is identified, researchers must run further tests to determine which neural pathways it might affect.

Researchers at Yale University now say they have sped up the process by using DNA cloning technology to build large libraries of spider venoms. This makes it easier to test the impact of a broad range of toxins on a particular neural pathway. They refer to the process as toxineering.

“This turns it around and says, for a particular ion channel target, can we identify, in the pharmacological diversity of the spider venom toxins, a toxin that is active against that desired target,” said Michael N. Nitabach, a physiologist at Yale and senior author of the paper, published in Current Biology.

Using the process, the scientists have identified a potential new painkiller: a toxin from the venom of the Peruvian green velvet tarantula that blunts activity in an ion channel linked to both inflammation and neuropathic pain known as TRPA1.

“We chose that target because it is a key factor in both normal-functioning pain as well as pathological pain syndrome,” Nitabach said.

Ethnicity influences the smell of earwax

The smell of a person’s earwax depends partly on his ethnic origin, a new study reports, suggesting that the substance could be an overlooked source of personal information.

The earwax of Caucasian men contains more volatile organic compounds than that of East Asian men, researchers at the Monell Chemical Senses Center in Philadelphia found. Twelve such compounds are common to both groups, they said, but 11 of those are more plentiful in Caucasians.

Monell researchers have previously found that underarm odor contains clues to a person’s age, health and sex. They suspected that earwax might contain similar markers, since a 2006 study found that a gene related to underarm odor, which also varies by ethnicity, helps determine a person’s type of earwax.

“We’re at the beginning of exploring a new and interesting biofluid secretion that has not been looked at in this manner before,” said George Preti, an organic chemist at Monell and the senior author of the new study, which was published in The Journal of Chromatography B.

Because of the fatty nature of earwax, or cerumen, Preti says it is a probable repository for odorants produced by diseases and the environment, and hence a potentially valuable diagnostic tool.

– New York Times