Breathe Easy, and Pity the Lonesome Mollusk
This week, we’ve gathered some tidbits from biomedical research. It’s hard, we admit, not to get sidetracked while perusing the latest scientific reports: Who wouldn’t be enthralled by the news that University of Florida entomologists are making strides in their studies of homosexuality in beetles, or that time is running out for Abigail the rare white abalone, the only one of her kind in captivity, who needs a male partner if she’s to breed?
But we digress.
* From New Scientist magazine, we learn that a Spanish chemist has devised a scheme for an accurate, pocket-size breath analyzer. People could use it to tell if their breath was getting overly ripe instead of resorting to that age-old, not very accurate method of cupping the hand over the mouth and breathing out while simultaneously trying to smell.
* Anyone left cold by the plight of poor old Abigail the abalone should jolly well be more grateful after reading this report, again in New Scientist: British researchers have devised a way to mass-produce--in a plant--a glue that mollusks like Abigail use to stick tight onto rocks. The glue might one day have medical uses, such as fixing broken teeth or rips in tissue.
* If you think making shellfish glue in plants is bizarre, have we got an item for you: Nature Biotechnology reports that French scientists have genetically engineered mice so that they produce human growth hormone in their semen. If large animals like boars were similarly engineered, they suggest, drug companies would have large amounts of human growth hormone, for medical uses, on tap. So to speak.
What an image. Let’s move on.
One Spider’s Web Is Another Man’s Suture
After reading about mollusk glue, we searched for other examples of useful medical proteins from odd animals. Halloween being so fresh in our minds--it’ll be weeks before we get rid of all those fake cobweb strands--it didn’t take long for us to think about spiders. And guess what? According to a scholarly paper titled (somewhat predictably) “Oh What a Tangled Web,” spider-web silk--so strong, so elastic--has been used through the ages for all kinds of (highly doubtful) medical applications.
People have wrapped warts with spider silk and then set them ablaze. They’ve dressed wounds with silk to stop bleeding and aid healing. Colonial Americans swallowed webs as a cure for asthma. The ancient Roman scholar-philosopher Pliny wrote that silk from a spider going up on its thread would help with diarrhea, while thread from a spider going down would cure constipation. (Really? Is that true?)
To learn more, we called molecular biologist Randy Lewis of the University of Wyoming in Laramie, who studies spider silk genes. Spiders make different kinds of silk, he says. Only one--dragline silk--is the really strong and stretchy protein that might one day make super-thin sutures for surgery; tough, stretchy artificial ligaments; or bionic dressings for wounds.
The mixed nature of webs, he says, is why there aren’t any big spider farms--that and the fact that spiders will kill other spiders that come too close. You’d need way too much acreage to get enough silk. Instead, Lewis’ lab and companies are trying to mass-produce the proteins other ways--in bacteria or by genetically engineering goats to produce them in milk.
That’s Disgusting! Just Ask Anybody
Talking of milking (the topic of Halloween, that is):
I recently co-hosted, at my kid’s school, one of those deals where you mix together strange-feeling and strange-smelling foods and label them things like “lizard guts” and “rotting vampire fingers.” All evening, kids dragging reluctant parents came up, felt the food, then ran away shrieking with disgust.
This got us wondering: Why do humans feel disgust anyway? What good is it?
Charles Darwin wrote that people all over the world seem to get disgusted and make the same expression when they feel it, implying that we inherit the capability. It’s been proposed that we evolved to feel disgust so we’d be less prone to eat bad-smelling, nasty-looking food that might poison us. But scholar William Ian Miller, of the University of Michigan in Ann Arbor--and author of “The Anatomy of Disgust” (Harvard University Press, 1997)--thinks disgust isn’t just to protect us against bad food. Feeling disgust, he says, helps us identify with people who are like us and revile those who are different. Which, though it may be evolutionarily useful, can also be--like--just gross.
