Massachusetts Institute of Technology
Massachusetts Institute of Technology

Scientists Develop Germ-Fighting Fake Mucus

Massachusetts Institute of Technology
Massachusetts Institute of Technology

We really don’t talk enough about the wonders of mucus. The goo produced by your nose, mouth, eyes, guts, and other parts is one of your greatest defenders, working hard to keep you safe in a germ-filled world. Now scientists have harnessed some of that power, creating a synthetic mucus that may help fight antibiotic-resistant bacteria. The research will be presented this week at the Experimental Biology 2017 meeting in Chicago.

Each of us produces about a gallon of mucus per day, enough to provide a thin coating over 2000 square feet of our innards. It’s a surprisingly versatile substance, for us and other animals. Last year, acoustic scientists reported that dolphins’ snot may be an essential ingredient in producing the clicks and whistles they use for echolocation. More recently, drug researchers found a powerful flu-fighting compound in the slime secreted by a tiny Indian frog.

Massachusetts Institute of Technology

Katharina Ribbeck is a tissue engineer at the Massachusetts Institute of Technology.

“I am so excited about mucus,” she said in a statement, “because I am convinced it can help us find new strategies for protecting us from infections, in particular those that relate to an overgrowth of harmful microbes.”

"Over millions of years, the mucus has evolved the ability to keep a number of these problematic pathogenic microbes in check,” she said, “preventing them from causing damage. But the mucus does not kill the microbes. Instead, it tames them."

Ribbeck and her colleagues focused on strand-like mucus molecules called mucins (shown above), specifically one called MUC5B that’s found in our spit. They pitted MUC5B against two common oral bacteria: the cavity-causing Streptococcus mutans and the beneficial Streptococcus sanguinis. Left to their own devices, harmful S. mutans rapidly overwhelmed S. sanguinis and created a dangerous imbalance. But when the researchers introduced the bacteria to an artificial mucus solution containing MUC5B, the two species played nicely, living in relative harmony.

"We conclude from these findings that MUC5B may help prevent diseases such as dental caries [cavities] by reducing the potential that a single harmful species will dominate," said Ribbeck.

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The Surprising Reason Why Pen Caps Have Tiny Holes at the Top
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iStock

If you’re an avid pen chewer, or even just a diehard fan of writing by hand, you’re probably well acquainted with the small hole that tops off most ballpoint pen caps, particularly those classic Bic Cristal pens. The reason it’s there has nothing to do with pen function, it turns out. As Science Alert recently reported, it’s actually designed to counter human carelessness.

Though it’s arguably unwise—not to mention unhygienic—to chomp or suck on a plastic pen cap all day, plenty of people do it, especially kids. And inevitably, that means some people end up swallowing their pen caps. Companies like Bic know this well—so they make pen caps that won’t impede breathing if they’re accidentally swallowed.

This isn’t only a Bic requirement, though the company’s Cristal pens do have particularly obvious holes. The International Organization for Standardization, a federation that sets industrial standards for 161 countries, requires it. ISO 11540 specifies that if pens must have caps, they should be designed to reduce the risk of asphyxiation if they’re swallowed.

It applies to writing instruments “which in normal or foreseeable circumstances are likely to be used by children up to the age of 14 years.” Fancy fountain pens and other writing instruments that are clearly designed for adult use don’t need to have holes in them, nor do caps that are large enough that you can’t swallow them. Any pen that could conceivably make its way into the hands of a child needs to have an air hole in the cap that provides a minimum flow of 8 liters (about 2 gallons) of air per minute, according to the standard [PDF].

Pen cap inhalation is a real danger, albeit a rare one, especially for primary school kids. A 2012 study [PDF] reported that pen caps account for somewhere between 3 and 8 percent of “foreign body aspiration,” the official term for inhaling something you’re not supposed to. Another study found that of 1280 kids (ages 6 to 14) treated between 1997 and 2007 for foreign body inhalation in Beijing, 34 had inhaled pen caps.

But the standards help keep kids alive. In that Beijing study, none of the 34 kids died, and the caps were successfully removed by doctors. That wasn’t always the case. In the UK, nine children asphyxiated due to swallowing pen caps between 1970 and 1984. After the UK adopted the international standard for air holes in pen caps, the number of deaths dropped precipitously [PDF]. Unfortunately, it’s not foolproof; in 2007, a 13-year-old in the UK died after accidentally swallowing his pen cap.

Even if you can still breathe through that little air hole, getting a smooth plastic pen cap out of your throat is no easy task for doctors. The graspers they normally use to take foreign bodies out of airways don’t always work, as that 2012 case report found, and hospitals sometimes have to employ different tools to get the stubbornly slippery caps out (in that study, they used a catheter that could work through the hole in the cap, then inflated a small balloon at the end of the catheter to pull the cap out). The procedure doesn’t exactly sound pleasant. So maybe resist the urge to put your pen cap in your mouth.

[h/t Science Alert]

Carnivorous Hammerhead Flatworms Are Invading France

It’s no hammerhead shark, but the hammerhead flatworm has become a real menace in France. Or at least a menace to earthworms, as Earther reports.

Believed to be an invasive species from Asia, the hammerhead flatworm was only recently recorded in France, as is documented in a new study (titled "Giant worms chez moi!") published in the journal PeerJ. However, based on reports, photographs, and videos sent in by citizens across the country, scientists determined the pests have gone undetected for nearly 20 years. This came as a shock, especially because the worms can measure more than a foot in length.

In recent years, three species of the carnivorous worm have quietly taken over French gardens and have even been spotted in metropolitan areas. Some species immobolize their prey with tetrodotoxin, the same powerful neurotoxin that makes pufferfish so poisonous. The worms secrete digestive enzymes, allowing them to dissolve earthworms and slugs their size.

Jean-Lou Justine, co-author of the study, says their eating habits are a concern. "Earthworms are a major component of the soil biomass and a very important element in the ecology of soils," Justine tells Earther. "Any predator which can diminish the populations of earthworms is thus a threat to soil ecology."

Archie Murchie, an entomologist who was not involved in the study, told The Washington Post that the worms will continue to spread in step with global trade. The worms were also seen in overseas French territories, including one worm with a blue-green hue that is probably a newly detected species, Murchie tells the newspaper.

[h/t Earther]

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