Giorgia squeri via Wikimedia Commons // CC BY-SA 4.0
Giorgia squeri via Wikimedia Commons // CC BY-SA 4.0

Are Cold Mice Skewing Cancer Study Results?

Giorgia squeri via Wikimedia Commons // CC BY-SA 4.0
Giorgia squeri via Wikimedia Commons // CC BY-SA 4.0

Designing experiments is a tricky task. In order to prove or disprove a hypothesis, scientists first have to eliminate or account for the influence of as many variables as possible. But in order to do that, first they must realize that these variables exist. A review article published today in the journal Trends in Cancer shows that standard laboratory temperatures—which are comfortable for humans but chilly for mice—are likely affecting biomedical study results. 

As oversights go, this is a pretty big one. Lab mice and rats are the subjects of more than 100,000 journal articles every year … and those are just the experiments that are published. But unlike dogs, cats, rabbits, or chimpanzees, mice and rats are not protected under the 1966 Animal Welfare Act, which regulates how research animals are treated. This lack of protection means that there has been relatively little research, and less regulation, regarding their treatment. 

This is a bad situation for rats and mice, and it’s not great for us, either. The mouse model, as it’s known, is generally seen as a pretty good indicator of how a given drug or medical occurrence may affect humans. So if tests on a cold mouse yield different results from those done on a mouse at a comfortable temperature, as two immunologists now argue, then millions of studies on drugs and disease have been affected.

Today, rodent research labs are kept between 68°F and 78.8°F. Researchers wear layers of protective gear, including gowns, gloves, and masks, so a higher temperature might cause them to overheat. Keeping the thermostat down also helps keep down the smell.

Image Credit:Guanxi (Christina) Qiao

But a mouse’s ideal temperature averages between 86°F and 89.6°F. A 70°F room will cause mice to shiver, which uses up their energy and affects their metabolism, blood flow, and heart rate. Realizing this, immunologists Bonnie Hylander and Elizabeth Repasky decided to take a look at the relationship between mouse temperature and study results. In 2013, they found that a cold mouse is less able to fend off tumors than one that’s toasty warm—a finding that had big implications for cancer drug research.

But these findings were just the start. Hylander and Repasky conducted a sweep of scientific literature, looking for studies like theirs. They found that researchers of obesity, inflammation, atherosclerosis, and a number of other diseases all concluded that keeping mice cold led to “significant differences in experimental outcomes.” 

"Most people only look at results from experiments at standard lab temperatures," Hylander said in a press statement. "They're not necessarily aware that if you repeat the experiments with mice at a different temperature, you might get a different outcome." 

Unfortunately, there’s no quick fix to be had here. “The mice want different temperatures for different parts of the day,” animal welfare scientist Brianna Gaskill told Dan Engber at Slate. “There is no way that humans can pick a single, perfect temperature for mice.” And, as mentioned earlier, what’s good for mice is not so good for researchers. 

Hylander and Repasky aren’t suggesting that labs simply turn up the heat. One approach might be for researchers to experiment with keeping the mice warm in incubators, or offering them more nesting material. They also recommend that researchers consider the effects of temperature in both their experimental design and their analysis of their results in the future. 

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IKEA
IKEA Is Recalling Its New Dog Water Fountain Due to Suffocation Risk
IKEA
IKEA

In late 2017, IKEA released LURVIG, its first-ever line for pets, a collection that included beds, leashes, food bowls, and other staple products for dogs and cats. Unfortunately, one of those products is now being recalled over safety issues, according to Fast Company. If you own the LURVIG water dispenser, you should take it away from your pet immediately.

The automatic water fountain poses a suffocation hazard, the company announced in a recent statement. The retailer has received two reports of pets dying after getting their head stuck in it.

A water fountain for pets sits next to a bowl full of dog food.
IKEA

The $8 water dispenser debuted in U.S. stores in October 2017 with the rest of its LURVIG line. Awkwardly enough, the product description included assurances of the product’s safety standards. It explained that “the LURVIG range was developed with the assistance of trained veterinarian Dr. Barbara Schäfer, who also works with product risk assessment at IKEA,” and went on to say that “the first thing to consider was safety: ‘Dogs will definitely chew on their toys and bring in dirt from their daily walks. Cats will definitely scratch on most surfaces and are sensitive to smell and texture. So safe, durable materials are very important.’”

It seems that smaller dogs are able to get their faces stuck in the dome-shaped plastic reservoir, which only appears to have one hole in it, at the bottom. As a result, dogs can suffocate if they can’t get out of it.

The product has been removed from IKEA’s website, and the retailer recommends that anyone who bought it stop using it and return it to the nearest IKEA store for a refund.

[h/t Fast Company]

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Alamy
10 Facts About the Portuguese Man O' War
Alamy
Alamy

Something a lot scarier than any Jersey Devil has been washing up on beaches in the Garden State lately: This month, the dangerous Portuguese Man O’ War—which has a potentially deadly sting—has been sighted in Cape May and Wildwood, New Jersey, which could lead to problems for beachgoers. Read on to learn more about these unusual creatures.

1. IT'S NOT A JELLYFISH.

The Portuguese Man o’ War may look like a bloated jellyfish, but it’s actually a siphonophore—a bizarre group of animals that consist of colonies made up of dozens, hundreds, or even thousands of genetically-identical individual creatures. A siphonophore starts out as a fertilized egg. But as it develops, it starts "budding" into distinct structures and organisms. These tiny organisms—called polyps or zooids—can’t survive on their own, so they merge together into a tentacled mass. They must cooperate as one in order to do things like travel and catch food.

Though the zooids within a Man O’ War are basically clones, they come in different shapes and serve different purposes [PDF]. Dactylozooids are long hunting tentacles built to ensnare prey; gastrozooids are smaller tentacles which digest the food; and gonozooids are dangling entities whose job is to facilitate reproduction. Every Man O’ War also has a pneumatophore, or “float”—an overgrown, bag-like polyp which acts as a giant gas bladder and sits at the top of the colony. Capable of expanding or contracting at will, it provides the Man O’ War with some buoyancy control. An expanded float also enables the colony to harness winds to move around.

2. A CLOSE RELATIVE IS THE INDO-PACIFIC “BLUEBOTTLE.”

A view of a bluebottle under water.
iStock

When we say “Portuguese Man O’ War,” we’re talking about Physalia physalis, the bizarre siphonophore that’s scaring New Jerseyans right now. Also known as the Atlantic Portuguese Man O’ War, it can be found in warmer parts of the Pacific, the Caribbean, the Indian Ocean, and of course, the Atlantic.

Another kind of siphonophore which regularly stings beachgoers is the so-called bluebottle, Physalia utriculus. It’s sometimes called the Indo-Pacific “Portuguese” Man O’ War and is restricted to the Pacific and Indian Oceans. It’s smaller than the Atlantic species and unlike its bigger counterpart—which has multiple hunting tentacles—it hunts with a single, elongated tentacle.

3. THE NAME “PORTUGUESE MAN O’ WAR” IS PROBABLY A NAVAL REFERENCE.

In the age of sailing, many European navies used tall warships loaded with cannons and propelled by three masts. British sailors took to calling this kind of vessel a “Man of War.”

What does that have to do with Physalia physalias? These colonies spend a lot of time floating at the water’s surface, and when the gas bladder is expanded, it looks—and acts—a bit like a sailboat, hence the “Man O’ War.” As for the Portuguese part, 19th century scientists proposed that sailors encountered it near the Portuguese island of Madeira, while modern etymologists tend to think that it looked like the Portuguese version of the ship.

Or at least that’s one explanation for the creature’s peculiar name. It’s also been suggested that Renaissance-era sailors thought the pneumatophores resembled the helmets worn by Portugal’s soldiers during the 16th century.

4. MAN O’ WAR TENTACLES CAN BE UP TO 165 FEET LONG.

Two Portuguese Man o' War washed up on the beach with their tentacles stretched out.
iStock

At least, that’s the maximum length for the dactylozooids—which are normally around 30 feet long and use venom-spewing cells to deliver painful, neurotoxic stings. When a tentacle is detached from the rest of the colony, it might wash ashore somewhere or drift around for days on end until it decomposes. Be warned: Even a severed tentacle can sting you.

5. ON RARE OCCASIONS, STINGS CAN BE FATAL TO HUMANS.

The odds of being killed by a Portuguese Man O’ War are slim. But just because deaths are rare doesn't mean you should touch one: On February 11, 2018, 204 people in Hollywood, Florida were treated for stings, which can lead to red welts on the skin, muscle cramps, elevated heart rates, and vomiting.

Still, the creatures can kill: One unlucky victim suffered a full cardiovascular collapse and died after getting too close to a Man O’ War in eastern Florida back in 1987. More recently, a woman swimming off Sardinia was stung by one and died of what was believed to be anaphylactic shock.

6. SOME FISH LIVE IN THEM.

Given that tiny fish make up about 70 to 90 percent of the Man O’ War’s diet (it also eats shrimp and other crustaceans), Nomeus gronovii, a.k.a. the Portuguese Man O’ War Fish, is playing a dangerous game: It lives among the siphonophore's tentacles even though it's not immune to its stings, swimming nimbly between the stingers. Young fish eat planktons which wander under their hosts and, as they get older, will sometimes steal the Man O’ War’s prey—or nibble on its tentacles.

7. SEA SLUGS LIKE TO STEAL THEIR TOXINS.

The Man O’ War has a long list of enemies. Loggerhead sea turtles and the bizarre-looking ocean sunfish are thick-skinned enough to eat them. There are also “blue dragon” sea slugs, which not only devour the Man O’ War but actively harvest and appropriate its toxins. After storing Man O’ War stinging cells in their own skins, the blue dragons can use it as a predator deterrent.

8. MAN O’ WAR COME IN PRETTY COLORS.

A pink-tinted Portuguese Man O' War with blue tentacles in the surf at a beach.
iStock

Although it’s translucent, the float is usually tinted with blue, pink, and/or purple hues. Beaches along the American Gulf Coast raise purple flags in order to let visitors know when groups of Man O’ War (or other potentially deadly sea creatures) are at large.

9. EVERY COLONY HAS A SPECIFIC SEX.

The Man O' War's gonozooids have sacs that house ovaries or testes—so each colony can therefore be considered “male” or “female.” Though marine biologists aren’t completely sure how the Man O’ War procreates, one theory is that the gonozooids release eggs and sperm into the open ocean, which become fertilized when they cross paths with floating eggs or sperm from other Man O’ War colonies. This “broadcast spawning” method of reproduction is also used by many species of coral, fan worms, sea anemone, and jellyfish.

10. LOOK OUT FOR MAN O’ WAR LEGIONS.

The Man O’ War isn't always seen in isolation. Legions consisting of over 1000 colonies have been observed floating around together. Because they drift along on (somewhat) predictable winds and ocean currents, it’s possible to anticipate where and when a lot of the creatures will show up. For example, the Gulf Coast’s Man O’ War season arrives in the winter months.

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