Masum Ibn Musa via Wikimedia Commons // CC BY-SA 4.0
Masum Ibn Musa via Wikimedia Commons // CC BY-SA 4.0

The Devious Strategy of the Mind-Controlling Cat-Poop Parasite

Masum Ibn Musa via Wikimedia Commons // CC BY-SA 4.0
Masum Ibn Musa via Wikimedia Commons // CC BY-SA 4.0

Toxoplasma gondii, a parasitic protozoan, infects more than 50 percent of people on Earth and millions of cats and other animals, yet the secrets to its success have largely remained a mystery—until now. A new study published in the journal Structure concludes that the parasite can hack into and rewire its host’s immune system to suit its own purposes.

You may not recognize this parasite by name, but you’ve probably heard it mentioned. T. gondii infection, better known as toxoplasmosis, has the power to produce strange changes in its hosts. The parasite can only reproduce within a cat’s body, and scientists believe that it can manipulate other animals to make that happen. Mice with toxoplasmosis lose their healthy fear of cats and will stroll right up to their predators, essentially delivering their parasitic passengers directly into the mouth of the beast.

Some scientists believe that toxoplasmosis can also influence human behavior, and studies have linked infection to symptoms of schizophrenia, bipolar disorder, and intermittent explosive disorder. Other researchers say these findings are overhyped, overblown, and impossible to reproduce.

Whether or not T. gondii can change our minds, it’s definitely changing our bodies. Toxoplasmosis can be dangerous for pregnant women and people with compromised immune systems, but most people never even know they’re sick—which is not how our bodies are supposed to work. Our immune systems are supposed to protect us from parasites like T. gondii, or, if they can’t, at least alert us by getting riled up and inflamed.

But somehow, this intruder found a way to override our personal security systems. The first clue to its strategy came last year, when scientists at the Institute for Advanced Biosciences discovered that T. gondii makes a protein called GRA24 that in turn convinces the body to make an inflammatory protein called p38α.

This raised a new question, one which became the focus of the new study: Why would a parasite ever want to trigger inflammation?

The researchers cultured human cells in the laboratory, then gave them toxoplasmosis and monitored the molecular-level interactions between the two proteins. They discovered that GRA24 can essentially hot-wire the security system and bypass multiple steps of the immune response process. By making its own p38α, T. gondii can control the flow and extent of inflammation. It doesn’t shut down the immune system; doing so could make its host sick and jeopardize the parasite’s new, cushy existence. Instead, it muffles the system just enough to keep itself safe and undetectable.

Watch your back, T. gondii. We're on to you.

Jamie McCarthy/Getty Images for Bill & Melinda Gates Foundation
Bill Gates is Spending $100 Million to Find a Cure for Alzheimer's
Jamie McCarthy/Getty Images for Bill & Melinda Gates Foundation
Jamie McCarthy/Getty Images for Bill & Melinda Gates Foundation

Not everyone who's blessed with a long life will remember it. Individuals who live into their mid-80s have a nearly 50 percent chance of developing Alzheimer's, and scientists still haven't discovered any groundbreaking treatments for the neurodegenerative disease [PDF]. To pave the way for a cure, Microsoft co-founder and philanthropist Bill Gates has announced that he's donating $100 million to dementia research, according to Newsweek.

On his blog, Gates explained that Alzheimer's disease places a financial burden on both families and healthcare systems alike. "This is something that governments all over the world need to be thinking about," he wrote, "including in low- and middle-income countries where life expectancies are catching up to the global average and the number of people with dementia is on the rise."

Gates's interest in Alzheimer's is both pragmatic and personal. "This is something I know a lot about, because men in my family have suffered from Alzheimer’s," he said. "I know how awful it is to watch people you love struggle as the disease robs them of their mental capacity, and there is nothing you can do about it. It feels a lot like you're experiencing a gradual death of the person that you knew."

Experts still haven't figured out quite what causes Alzheimer's, how it progresses, and why certain people are more prone to it than others. Gates believes that important breakthroughs will occur if scientists can understand the condition's etiology (or cause), create better drugs, develop techniques for early detection and diagnosis, and make it easier for patients to enroll in clinical trials, he said.

Gates plans to donate $50 million to the Dementia Discovery Fund, a venture capital fund that supports Alzheimer's research and treatment developments. The rest will go to research startups, Reuters reports.

[h/t Newsweek]

A New Analysis of Chopin's Heart Reveals the Cause of His Death

For years, experts and music lovers alike have speculated over what caused celebrated composer Frederic Chopin to die at the tragically young age of 39. Following a recent examination of his heart, Polish scientists have concluded that Chopin succumbed to tuberculosis, just as his death certificate states, according to The New York Times.

When Chopin died in 1849, his body was buried in Paris, where he had lived, while his heart was transported to his home city of Warsaw, Poland. Chopin—who appeared to have been ill with tuberculosis (TB)—was terrified of the prospect of being buried alive, and nostalgic for his national roots. He asked for his heart to be cut out, and his sister later smuggled it past foreign guards and into what is now Poland.

Preserved in alcohol—likely cognac—and stored in a crystal jar, Chopin's heart was laid to rest inside Holy Cross Church in Warsaw. (It was removed by the Germans in 1944 during the Warsaw Uprising, and later returned.) But rumors began to swirl, as the same doctor tasked with removing the heart had also conducted an autopsy on the composer's body, according to the BBC.

The physician's original notes have been lost, but it's said he concluded that Chopin had died not from TB but from "a disease not previously encountered." This triggered some scholars to theorize that Chopin had died from cystic fibrosis, or even a form of emphysema, as the sickly musician suffered from chronic respiratory issues. Another suspected condition was mitral stenosis, or a narrowing of the heart valves.

Adhering to the wishes of a living relative, the Polish church and government have refused to let scientists conduct genetic tests on Chopin's heart. But over the years, teams have periodically checked up on the organ to ensure it remains in good condition, including once in 1945.

In 2014, a group of Chopin enthusiasts—including Polish scientists, religious officials, and members of the Chopin Institute, which researches and promotes Chopin's legacy—were given the go-ahead to hold a clandestine evening meeting at Holy Cross Church. There, they removed Chopin's heart from its perch inside a stone pillar to inspect it for the first time in nearly 70 years.

Fearing the jar's alcohol would evaporate, the group added hot wax to its seal and took more than 1000 photos of its contents. Pictures of the surreptitious evening procedure weren't publicly released, but were shown to the AP, which described Chopin's preserved heart as "an enlarged white lump."

It's unclear what prompted a follow-up investigation on Chopin's heart, or who allowed it, but an early version of an article in the American Journal of Medicine states that experts—who did not open the jar—have newly observed that the famed organ is "massively enlarged and floppy," with lesions and a white, frosted appearance. These observations have prompted them to diagnose the musician's cause of death as pericarditis, which is an inflammation of tissue around the heart. This likely stemmed from his tuberculosis, they said.

Some scientists might still clamor at the prospect of testing tissue samples of Chopin's heart. But Michael Witt of the Polish Academy of Sciences—who was involved in this latest examination—told The Guardian that it was unnecessary to disturb what many consider to be a symbol of national pride.

"Some people still want to open it in order to take tissue samples to do DNA tests to support their ideas that Chopin had some kind of genetic condition," Witt said. "That would be absolutely wrong. It could destroy the heart, and in any case, I am quite sure we now know what killed Chopin."

[h/t The New York Times]


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