Connect with us

Health

From Marie Curie to the Demon Core: When Radiation Kills

Cherenkov radiation glowing in the core of the Advanced Test Reactor at Idaho National Laboratory. (Credit: Argonne National Laboratory)

When we hear the word “radiation,” we tend to think of atomic bombs (like the ones that fell on Hiroshima and Nagasaki), or environmental mishaps like the three-eyed fish living outside Springfield’s nuclear power plant on The Simpsons. But radiation – a term that refers to the transmission of energy through waves and particles – is not always a destructive force.

“The word radiation is a lot broader than people realize,” says Johnathan M. Links, a medical physicist and professor at Johns Hopkins School of Public Health. “When people say radiation, what they usually mean is ionizing radiation, which has sufficient energy to eject electrons from atoms. Non-ionizing radiation doesn’t have that capability, and that’s an important distinction. When you eject electrons from atoms you can break chemical bonds, and that’s what leads to the microscopic and macroscopic damage that radiation causes.”

By breaking those chemical bonds inside our bodies, ionizing radiation can destroy or damage critical components of our cells, leading to injury, and at high enough doses, death. And low-level exposure can damage our DNA, potentially creating harmful mutations down the road.

Human beings are exposed to radiation everywhere in our environment: Heat up leftovers in the microwave or turn on a lightbulb, and you’re getting a dose of non-ionizing radiation. But even ionizing radiation – the kind that’s capable of causing cellular damage – is everywhere, from the soil to the foods we consume. Each year, human beings are exposed to 300 millirads of naturally-occurring ionizing radiation, what’s called “background radiation.”

Exposure to ionizing radiation over time (even in small doses) increases the risk of developing cancer. But the amount of background radiation we’re exposed to yearly is so small, human beings would have to live for thousands of years before it could do any damage. However, when humans are exposed to very large amounts of ionizing radiation in a short period of time, Acute Radiation Syndrome (ARS) occurs.

“There’s a very noticeable threshold for developing radiation sickness, and in big round numbers that threshold is around 100 rads,” says Links. (For context, a mammogram is only 0.4 rads, or approximately 7 weeks of background radiation exposure.) People exposed to 100 rads start to show signs of ARS, which include fatigue, nausea, vomiting, diarrhea, and seizures – and the higher the dose, the more likely death is to occur.

“Depending on the dose, you could die in 2-3 weeks as the blood-forming cells in your bone marrow shut down, or you might die in a matter of days because your GI tract is affected and you can’t absorb nutrients,” Links says. Generally speaking, anything over 600 rads is considered a lethal dose.

And it’s happened before, although such incidents are fairly rare. Whether it was because the effects and sources of radiation weren’t fully known or because of an unfortunate accident, human beings have encountered deadly doses of radiation before. Here are five of the most notable incidents.

Ebenezer Byers

Born in 1880, Ebenezer (“Eben”) Byers was a wealthy socialite and amateur golf champion from Pittsburgh, PA. After an injury in 1927, Byers was prescribed a tonic called Radithor in the hopes it would ease his pain and improve his health. (It didn’t.) Over the next two years, Byers guzzled an estimated 14,000 bottles of Radithor, causing his jaw, teeth, and parts of his skull to dissolve. After a protracted illness, Byers died of radiation sickness in March 1932 at the age of 51.

Marie Curie

Internationally renowned chemist and physicist Marie Curie is famous for discovering the radioactive elements polonium and radium, along with being the first woman to snag the Nobel prize in physics and chemistry. But what she’s also famous for is carrying vials of radium around in the pocket of her lab coat or storing them in her desk, marveling at their unearthly blue-green glow. Unfortunately, the habit exposed Curie to high levels of ionizing radiation. She succumbed to aplastic anemia in 1934, a condition characterized by bone marrow cells that don’t produce new blood cells. Curie was exposed to such a large dose of radiation, in fact, that her personal effects are still radioactive and will remain so for another 1500 years. Visiting scientists who want to view Curie’s notebooks are required to sign a waiver and wear protective gear.

The Radium Girls

Radium dial painters working in a factory. (Credit: Wikimedia Commons)

Radium dial painters working in a factory. (Credit: Wikimedia Commons)

After Marie Curie discovered it in 1898, radium started appearing everywhere. Not just in tonics like Radithor, but as an additive in everything from toothpaste to cosmetics. In 1916, the United States Radium Corporation opened a factory in Orange, NJ and hired 70 young women to paint numbers on wristwatches with luminous paint. Because the toxic effects of radium were not totally known (the girls, in fact, thought working around radium would improve their health), the factory workers painted the radium on their nails and skin, admiring the way they glowed after a day of work. What’s worse, their employers had the girls draw the brushes between their lips to create a fine point on the end of the paintbrush – meaning they were literally ingesting radium every single day. When the factory workers – now known as “the radium girls” – started showing signs of sickness and bone decay, they sued the U.S. Radium Corporation – and won. Many of the original radium girls were dead of radiation sickness within five years.

The Demon Core Incidents

After the incidents of the 1920s, the acute and chronic effects of ionizing radiation exposure were more clearly understood. Thanks to the outspokenness of the Radium Girls and coverage from the news media, radium was taken off the market and civilian exposure became much more rare. However, scientists were beginning to study nuclear energy to develop the atomic bomb for military use – and sometimes, radiation sickness resulted.

A replica of what the Demon Core would have looked like at the time of the accident. (Credit: Los Alamos National Laboratory/Wikimedia Commons)

A replica of what the Demon Core would have looked like at the time of the accident. (Credit: Los Alamos National Laboratory/Wikimedia Commons)

At the Los Alamos National Laboratory in New Mexico, Manhattan Project physicist Harry K. Daghlian was conducting an experiment alone, at night, with an enormous round sphere of plutonium. The sphere was the exposed core of a nuclear weapon, and Daghlian was attempting to build a neutron reflector, a device that would make it easier to produce a nuclear reaction, from stacked bricks of tungsten carbide. The sphere was stable, but as more neutrons were reflected back it inched closer to criticality, the point at which a sustainable nuclear reaction would begin. As Daghlian layered his bricks, his monitoring equipment told him that the core was about to turn supercritical. Daghlian attempted to remove a brick – but instead dropped it on the plutonium sphere, rendering the sphere supercritical and exposing himself to thousands of rads of ionizing radiation. He died 25 days later.

Strangely, one year later, another physicist named Louis Slotin was conducting a similar criticality experiment on the core and dropped it. The sphere sent out a burst of radioactivity in a bright blue flash of light, and Slotin was exposed to a similarly intense burst of radiation. Although he initially seemed fine, Slotin quickly developed nausea, vomiting and radiation burns, and his white blood cell count plummeted. He was hospitalized and died of radiation sickness within 9 days.

Zaragoza Radiotherapy Incident

Ionizing radiation gets a bad rap. Even though exposure can increase the likelihood of getting cancer over a lifetime, it can also diagnose and treat cancer as well. Since its invention in 1895, people have used X-rays to locate cancerous tumors in the body and relied on radiation therapy to shrink them.

In one unfortunate accident in 1990, cancer patients receiving radiation treatments at the Clinic of Zaragoza, in Spain, were blasted with a high dose of radiation during therapy – up to seven times higher than the appropriate dose, thanks to faulty machinery. In all, 27 patients were irradiated, causing damage to their skin and internal organs. 20 of the 27 patients who were irradiated developed sickness from radiation exposure and died of various ailments within five years.

Radiation is a powerful force – able to kill and to save lives. When radiation kills, it can be disastrous – but these disasters have also taught us to be careful with this powerful phenomenon. It’s a hard-earned lesson indeed.

Continue Reading
Advertisement
Click to comment

Health

Strange Drug Overdoses Are Mystifying Hospitals

A new wave of synthetic drugs is causing overdoses across the country. (Credit: busliq/shutterstock)

An explosion of strange new narcotics is hitting the streets, as clandestine chemists rush to produce drugs that exist outside the law.

One United Nations report tallied 644 new drugs discovered across 102 countries and territories between 2008 and 2015. And in an interview last year, a Drug Enforcement Administration spokesperson said they encounter previously unheard of drugs on an almost weekly basis.

Known as new psychoactive substances (NPS), these drugs appear faster than governments can ban them — not that banning does much. But the speed means drug users sometimes don’t know what they’re taking. And in cases of overdose, medical professionals are sometimes at a loss for how to treat patients.

A newly released study funded by the Office of National Drug Control Policy gives a small picture into just how bad the problem is. A team of researchers in Maryland wanted to see the prevalence of new drugs in hospital visits, especially synthetic cannabinoids (SC), drugs colloquially known as “Spice” or “K2” that can mimic some of the effects of marijuana.
Rashes of overdoses across the U.S. have been linked to synthetic cannabinoids, including last week when more than 100 people overdosed (but didn’t die) in New Haven, Connecticut, in just 48 hours. These new drugs have been implicated in “zombielike” behavior, psychosis, cardiac arrest and seizures, or have been laced with brodifacoum, a rat poison.

So there’s strong incentive for emergency rooms to know what they’re dealing with. Yet this group of researchers at the ONDCP found it was harder than they expected to figure out what specific drugs were causing these overdoses.

What’s In Your Urine?

In 2016, the researchers obtained nearly 200 urine samples from two hospital emergency departments in Maryland and screened for 169 different drugs, including 26 synthetic cannabinoids. They wanted to include more, but in some cases, these drugs are so new that reference standards for urine testing didn’t yet exist. Typically, the hospitals screen for less than nine drugs — but not any synthetic cannabinoids.

The 175 patients who provided their pee either showed up in the ER complaining of symptoms related to SC use, were caught with it by police or medical staff, or seemed to be agitated, hallucinating, or unresponsive thanks to an unknown drug.

Yet only one sample came back positive for SCs, which suggested that these overdoses were caused by drugs not included in the test panel. So a year later, the researchers retested the urine for an additional 20 synthetic cannabinoid metabolites.

Still, only about a quarter of the specimens returned with positive results, which was much lower than expected. The most commonly found synthetic cannabinoid was MDMB-FUBINACA, which is now illegal, but has been sold in vaporizer e-liquids and was linked to 25 deaths and hundreds of hospitalizations in Russia, according to the state-controlled news site RT.

“Even after we excluded the persons enrolled in the study for agitation from an unknown cause, we found that the percentage testing positive for SC only increased to about 24 percent in each hospital,” the researchers wrote. “On the other hand, these specimens were found to contain a variety of other drugs, many in combination with one another, that had likely caused their symptoms.”

Testing, Testing…

Even with the 175 patients tested in this study, it’s a small sample size that may not represent the majority of people who use synthetic cannabinoids, especially given the high rate of multiple drug use in these cases. An average of 91 percent of those who tested positive for SC in this study had at least one other drug in their system.

And it’s not clear if the patients always knew what they were taking — they may not have even known they were taking SCs — but certain chemical combos can have different adverse effects.

“The continuously changing nature of the substances available make it difficult to develop urine tests for all of the new drugs as quickly as they are discovered,” the scientists wrote. “Even though we re-tested our specimens with a larger panel of SC metabolites, it is still possible that our results underdetected the SC that these patients might have used.”

Some patients were not included in the study because urine samples couldn’t be obtained. It’s also possible that some urine samples degraded before they could be detected.

This study demonstrates how difficult it is — and how ill-equipped most hospitals are — to detect and treat overdoses from new psychoactive substances. Even if your urine screen can expose hundreds of chemicals, it needs to be updated frequently, which is why some compare this issue to a game of Whac-a-Mole. As soon as one drug is made illegal, another, often more deadly drug, takes its place.

Continue Reading

Health

People Were Definitely High For the 2017 Solar Eclipse, Study Finds

(Credit: Thanakrit/Santikunaporn)Shutterstock)

Day turning to dusk in the span of minutes, sunsets all around, a jewel-bright ring in the sky where the sun once stood — an eclipse is an otherworldly experience. But, if there’s one thing we like to do with amazing experiences, it’s try to make them better. Though you may have already guessed, a new study provides the confirmation: Lots of people got high for the 2017 solar eclipse.

The new data comes courtesy of a study from a group of researchers from Murray State University in Kentucky looking at how celebratory events affect drug use. They compared two towns in Kentucky on a normal week and the Fourth of July, and looked at the solar eclipse in one town and the first week of a college semester in the other.

In the Water

Drug use being the kind of thing people don’t necessarily like to make public, the researchers turned to a clever, and increasingly common, method of assessing what and how much people were putting into their bodies: They simply analyzed the sewage water. What goes into our bodies must come back out, and most drugs show up in our urine wholesale or betray their presence through signature metabolites our bodies break them down into. It’s a much more accurate and timely method of measuring drug use than relying on self-reported surveys or estimates based on drug busts, and it’s been used all over the world, though not often in the U.S.

“We can utilize this technique to determine the level of drugs people are consuming yesterday, today,” says Bikram Subedi, an assistant professor at Murray State University and a co-author of the study. “Within 24 hours we can get all the results.”

The researchers took samples from wastewater treatment plants before, during and after big events and sampled them in the lab for the markers of drug use. Big celebrations, unsurprisingly, have a noticeable effect on drug use, they found, in research presented today at the 256th National Meeting & Exposition of the American Chemical Society. Both the Fourth of July and the solar eclipse produced significant spikes in levels of a range of drugs, from weed to cocaine to MDMA, when compared to a baseline reading.

Black Hole Sun

Compared to a more prosaic celebration like the Fourth of July, though, the eclipse seems to have encouraged a somewhat different kind of drug use. Marijuana, MDMA and amphetamine (a broad class of stimulants that includes drugs like Adderall and Vyvanse) use were all significantly higher during the eclipse than during the Fourth. More worryingly, though, drugs like morphine, cocaine and methamphetamine all spiked during the eclipse, though not as much as during the Fourth. The researchers didn’t look at other psychedelic drugs like LSD, psilocybin or DMT.

The one drawback to the work, however, is that they weren’t able to control for the massive influx of people the eclipse, and to a lesser extent events like the Fourth, brought. Some towns in the path of totality saw more than 10,000 people flood in for the event, so it’s impossible to say whether people did more drugs during the eclipse, or if there were simply more people around to do them.

The takeaway here is two-fold. One, we can prove that, yes, people did get high during the eclipse, using the stunning celestial alignment as a opportunity to try and expand their minds further under the influence of psychoactive substances. (No one seems to have gone blind while tripping on LSD , though, as one bit of 1960s anti-drug propaganda had it.)

On another level, however, it reveals that celebrations present an even greater danger for people addicted to already harmful drugs like meth and opioids. What’s more, that correlation holds whether it’s an established holiday like the Fourth of July or a more uncommon event like the eclipse. As the opioid crisis continues, the information could be helpful for everyone from police officers to hospital administrators who must deal with the the effects of addiction and overdose.

Their work, and similar analyses worldwide, are indicating that we may have underestimated howe many drugs are actually being consumed, something that has real implications for public health agencies. In the future, Subedi hopes that such wastewater monitoring can be carried out in larger cities and over extended periods of time. Such a project would track the ebb and flow of drug use to better inform the ways that we as a society deal with illicit substances.

And, with another eclipse set to blaze a path across the U.S. in 2024, the study offers a preview of what we might expect in terms of some people’s viewing plans.

Continue Reading

Health

Uncertain Hope Blooms for Tasmanian Devils

Using remote camera traps, photographer Heath Holden captured rare images like this one of wild Tasmanian devils (Sarcophilus harrisii) in their natural habitat. The animals’ bright red ears and eerie, raucous scuffles earned the scrappy marsupials their haunting common name. (Credit: Heath Holden)

On a misty summer morning in 2015, Manuel Ruiz ditched his pickup truck along a dusty two-track road in northwest Tasmania and trod into a grove of eucalyptus. He was searching for a devil. “If I were a devil, this would be a nice place to spend the night,” thought Ruiz, a wildlife veterinarian and doctoral candidate at the University of Tasmania.

The Tasmanian devil (Sarcophilus harrisii) is the world’s largest carnivorous marsupial. Despite that distinction, the animal is only about the size of a raccoon. But what the species lacks in heft, it makes up for with tenacity. At night, devils hunt and scavenge wallabies, possums, and other small mammals under the cover of their black fur. During the day, they retreat to underground dens and sleep off the rigors of their nighttime exploits.

As picturesque and wild as northwest Tasmania’s landscape may be, it is also a battleground for disease, and in 2015, Ruiz was patrolling the epidemic front lines. It didn’t take him long to find evidence of the fight. A few dozen paces into the undergrowth, he knelt to inspect a white cylindrical trap nestled amidst a lush cluster of ferns. Inside, a female devil peered down her pointed, whiskered snout at Ruiz. He had seen this individual, nicknamed Leesa, once before. A raw, oozing tumor as large as a ping-pong ball gaped behind the right corner of her mouth—the mark of a debilitating cancer.

Leesa and thousands of other devils suffer from what’s known as devil facial tumor disease. The cancer was first detected in 1996 in eastern Tasmania. Since then, it has spread rapidly across the island state, causing an overall species decline of 80 percent, with localized declines of more than 90 percent. A decade ago, scientists predicted imminent extinction for the critically endangered species.

Since then, some wild devils have begun to show signs of resistance, offering new hope for the species’ survival. And while the quickly spreading cancer has wrought great devastation, it has also offered scientists a rare window into the progression of cancer at large. Researchers are monitoring the disease as it runs its course, searching for clues that will help them derail it. They’re hopeful that their findings might soon be applied to combatting cancers in other species—maybe even in humans someday.

A Tasmanian devil with two large facial tumors walks along a fire trail at night. These tumors, caused by a form of cancer, can grow so large that they ultimately prevent the animal from feeding.

A Tasmanian devil with two large facial tumors walks along a fire trail at night. These tumors, caused by a form of cancer, can grow so large that they ultimately prevent the animal from feeding. (Credit: Heath Holden)

no matter what species it’s in,” says Greg Woods, an immunologist who recently retired from the Menzies Institute for Medical Research at the University of Tasmania after two decades studying the devils. Genetic mutations trigger runaway tissue growth, which leads to detectable tumors in most forms of cancer. “It’s the same mechanism,” says Woods, “just in the devils’ case it’s transmissible.”

Most cancers arise within their hosts and die along with them. But some are infectious, shuttled by agents like viruses (as in California sea lions), bacteria, or other microscopic vehicles. In devil facial tumor disease, the cancer cells themselves are the infectious agents—making the tumors transmissible from one individual to another. Transmissible cancers are not well understood, partly because they only recently landed on researchers’ radar screens. Of the eight known transmissible cancers identified so far in devils, dogs, and marine invertebrates, seven were detected within the past three decades.

A devil is captured with a visible DFTD (Devil Facial Tumour Disease) near the upper canine and is checked out and a biopsy is taken for further study.

A devil is captured with a visible DFTD (Devil Facial Tumour Disease) near the upper canine and is checked out and a biopsy is taken for further study. (Credit: Heath Holden)

Devil facial tumor disease is passed from devil to devil through physical contact. Individuals brawl, bite, and scratch one another in competition for food and throughout the breeding season. (Early European settlers likened the haunting hisses and growls of their scuffles to the sounds of the Devil, and the name stuck.) During these clashes, an infected individual can transfer live tumor cells from its open wounds to a healthy devil’s face. The cells then grow into disfiguring, puffy blights that bloom in and around the animal’s mouth, face, and neck. Once contracted, the cancer is almost always the kiss of death.

Tumors may take down their host in a number of ways: by acquiring deadly bacterial infections; by growing so large they physically prevent the devil from feeding; or by metastasizing to other systems in the body and eventually causing organ failure. Once facial tumors appear, the cancer typically kills its host within six months to a year.

Scientists from government agencies and research institutions across Tasmania are tracking how devil populations fare in the wake of the cancer’s swift spread. Monitoring teams routinely visit sites across the island, staggering their data collection geographically to complement one another. Ruiz, who is a member of the University of Tasmania team, tracks the devil’s physiological response at several sites stricken by cancer in the northwest region. Out in the field, he and his colleagues snap mugshots of all individual devils they capture, which, when viewed as a collection, are reminiscent of a Most Wanted poster. Along with tissue samples, these photos allow the team to assess tumor growth over time.

Visitors observea captiveTasmanian devilat Trowunna Wildlife Sanctuary, one of the first facilities to successfully breed devils in captivity and now a recognized authority on devil husbandry.

Visitors observea captiveTasmanian devilat Trowunna Wildlife Sanctuary, one of the first facilities to successfully breed devils in captivity and now a recognized authority on devil husbandry. (Credit: Heath Holden)

The scientists also analyze blood samples to chart the devils’ immune response as the cancer progresses. “We can be collecting blood samples, and the devils are just snoring away without a care in the world,” says Ruiz, who has trapped, micro-chipped, and tracked more than 400 devils. “They seem like a little teddy bear when they’re asleep—but with big jaws that can chop your finger off at any time.”

Even perfectly healthy devils are short-lived: Most individuals live just six years. Since the cancer’s outbreak two decades ago, several generations of devils have come and gone, and that short generation time may confer a selective advantage. People often think of evolution as happening over thousands or millions of years, but, according to Ruiz, it’s happening right now in Tasmanian devils and their cancer. “This is one of the most interesting systems in the world for understanding the evolution of pathogens and their hosts,” Ruiz says.

Once it emerged, devil facial tumor disease moved swiftly. Its progression through Tasmania was so alarming that the government launched the multi-stakeholder Save the Tasmanian Devil Program a mere seven years later. As an insurance measure, the program established a disease-free population of devils on an island off the Tasmanian coast. Nearly two-dozen zoos and wildlife parks across mainland Australia and Tasmania also pitched in to help maintain genetic diversity in captive populations. By 2013, the program had raised more than 500 captive, healthy devils. But officials were reluctant to re-introduce these individuals into the wild; odds were too high that the animals would contract the cancer and die.

An expectant mother will lay down a trail of saliva for newborn pups to follow as they wriggle from the birth canal to her pouch. There they find warmth, protection, and nourishment.

An expectant mother will lay down a trail of saliva for newborn pups to follow as they wriggle from the birth canal to her pouch. There they find warmth, protection, and nourishment. (Credit: Heath Holden)

That same year, scientists discovered that devil facial tumor disease had the capacity to hide markers on its cell surfaces. These molecules are what typically signal to the immune system that an intruder is present. With this discovery in mind, a team led by Woods at the Menzies Institute set out to develop a vaccine that could direct the devil’s immune system to recognize and target the cancer cells despite the inherent absence of more obvious signals. They first treated dead cancer cells with cytokines, special molecules that force the disease cells to express their surface markers. This makes the cancer recognizable to the body’s immune defenses. The team then injected these modified cancer cells into healthy devils. By delivering two types of immune-activating molecules known as antigens and adjuvants at the same time, the devils’ immune systems sprang into action—flagging the injected cells and producing antibodies to fight back. “We’re fighting cancer with cancer,” says Woods.

The scientific community was buoyed by the promise of this finding. But the trials had their limitations. Sample sizes were small, and vaccinated individuals released into the wild were sometimes difficult to catch again, making it a challenge to measure the vaccine’s effectiveness. Additionally, most of the animals that were eventually recaptured came back with malignant growths, indicating that while the vaccine could stimulate the immune system to produce tumor-fighting antibodies, it wasn’t protecting the devils from contracting cancer in the wild.
A year later, just as vaccine research was gaining momentum, researchers detected a new transmissible facial cancer in devils—a genetically distinct cell line that also causes tumorous boils across the face. So far, scientists have diagnosed only about a dozen devils with the new cancer. But they already know that it’s possible for an individual to contract both types simultaneously.

“There’s something that might make devils more susceptible to disease,” says Rodrigo Hamede, a research fellow at the University of Tasmania, and one of Ruiz’s advisors, who studies the ecology of transmissible cancer. According to Hamede, the emergence of a second transmissible cancer in the same species is rare and raises many questions about the perfect storm of factors that has targeted devils twice in just 20 years. He hopes to identify what makes devils susceptible; his findings may shed light on whether we could see a transmissible cancer emerge in humans someday.

A curious Tasmanian devil peeks through a window at Trowunna Wildlife Sanctuary.In the wild, devils roam highly diverse habitats, from sandy beaches to lush rainforests and the high alpine.

A curious Tasmanian devil peeks through a window at Trowunna Wildlife Sanctuary.In the wild, devils roam highly diverse habitats, from sandy beaches to lush rainforests and the high alpine. (Credit: Heath Holden)

When Ruiz first trapped Leesa in the summer of 2015, four of her teats were engorged, a sign that she had nursing pups awaiting her return to the den. Despite the gaping wound on her face, she was docile and calm when he interacted with her, which is typical of wild devils. (Captive devils often show more aggression toward humans.) When Leesa showed up in one of his traps a third time, five months later, Ruiz was happy to see that she had survived the disease long enough to raise and wean her pups. And to his delight, her tumor had taken an unexpected turn.

Once raw and red, the lump on her right cheek now gleamed with healthy tissue. Ruiz thumbed through Leesa’s previous datasheets in excitement to confirm before phoning Hamede from the field: Leesa’s tumor had naturally regressed. Somehow, she had developed antibodies to fight the disease.

Leesa was not the first wild devil to show spontaneous tumor regression. The University of Tasmania team had detected six other individuals with naturally regressing tumors before Leesa’s case was documented. Since then, eight more animals—a total of 15 devils at northwest monitoring sites—have shown signs of regression. And other individuals are simply living longer with their tumors; although transmission rates have remained high in northwest Tasmania, mortality rates and the overall devil population in the region have stabilized.

Adult female devil, Leesa is released from the scientist, Manuel Ruiz's mesh bag after her checkup. Leesa is one of very few devils who has been recored to have tumour regression in the wild.

Adult female devil, Leesa is released from the scientist, Manuel Ruiz’s mesh bag after her checkup. Leesa is one of very few devils who has been recored to have tumour regression in the wild. (Credit: Heath Holden)

Armed with this information, scientists have been working to understand why some individuals are responding differently to the disease. Two years ago, a team that included Hamede looked at whether the species could be evolving natural mechanisms to combat devil facial tumor disease. They compared individuals from three sites across Tasmania, all born four to six generations after the cancer’s outbreak, and detected rapid changes in their genomes; two regions of genetic code in particular looked different. These regions contain genes that are known to influence cancer risk and immune function in humans—suggesting that devils could be evolving resistance. If scientists can firmly establish that certain devils have evolved resistance to the cancer, they may be able to accelerate the recovery of the species by introducing immune individuals into populations that currently lack genes for resistance.

Devils aren’t the only species benefitting from this research. Hamede hopes that what we learn from devils will inform immunotherapy—harnessing the body’s immune system to combat cancer—when treating other cancers, even those in humans. He and his colleagues are investigating differences in immune profiles in wild devils and the role they might have in the animals’ ability to resist tumors. By analyzing facial tumor disease and human cancer side by side, scientists can learn more about the fundamental role the immune system plays in combatting disease. “We have a more holistic view of cancer now that we wouldn’t have had without devils,” says Hamede.

Meanwhile, Woods’s team continues working to develop a vaccine that can prevent devils from contracting facial tumor disease. In the most recent trials, the team vaccinated more than 50 disease-free individuals from insurance populations and released them into the wild. Some animals were fitted with GPS collars to allow for higher recapture success and follow-up immunizations. The study found that 95 percent of vaccinated individuals produced antibodies that combat the disease.

The next step is seeing whether the vaccine can be strengthened in a way that would lead to tumor regression and keep devils from contracting facial tumor disease in the first place. The team remains optimistic that in the not-too-distant future, captive devils destined for the wild might be released with full immunity to the disease. These introductions will bolster wild populations that are still hanging on, despite the dire predictions issued a decade ago.

Ruiz last trapped and released Leesa in August of 2016, when she was an elderly 7 years old. While he assumes she no longer patrols the eucalyptus forests of northwest Tasmania, he feels strongly that Leesa likely died of old age or another natural cause—not from cancer.

[This article originally appeared in bioGraphic.]

Continue Reading

#Parasites

@VP Remove these #PARASITES FROM OUR COUNTRY Punish all the material supporters of #IllegalImmigrants

Ancient Roman 🏛️ Poop 💩 Shows Rich And Poor Were Infected By Different Parasites 🐛 via @forbes forbes.com/sites/kristina… #roman #archaeology #parasites #poop #feces

#Ivermectin

Trending