Connect with us

Health

10 Ways Space Changes the Body

Former astronaut Mark Kelly (left) poses with his identical twin brother, astronaut Scott Kelly (right). As part of NASA’s Twins Study, Scott spent nearly a year in space, while Mark stayed here on Earth. This gave researchers a chance to study the health effects of long-term spaceflights. (Credit: NASA)

Scott and Mark Kelly are identical twin brothers. Though that alone does not make them unique, what does is the fact that they are also both astronauts. In order to take advantage of the Kellys’ unique situation, NASA scientists decided to conduct a detailed study on the twins, aimed at unraveling how nature versus nurture plays out in space.

As part of NASA’s Twins Study, researchers collected biological samples from each of the Kellys before sending Scott to the International Space Station for a year starting in March 2016. Meanwhile, his brother Mark, who retired as an astronaut in 2011, remained on Earth to serve as the control subject. By analyzing how each twins’ biological markers evolved during the mission, the researchers learned a great deal about how the human body reacts — both physically and mentally — to extended periods of spaceflight.

The NASA Twins Study is made up of ten distinct research projects, which all focus on different aspects of the human body. And last month, after nearly two years of study, the ten separate research teams confirmed their preliminary findings (which were initially released in 2017), as well as presented details on their postflight follow-up results.

Later this year, the findings for each of the various projects will be integrated together and released as one summary paper, which will be followed by several companion papers focusing on the individual studies. In the meantime, here is a summary of the most recent findings for each of the research projects that were carried out as part of the Twins Study.

#1 – Telomeres get longer during spaceflight

Telomeres are the caps that shield the ends of our chromosomes, protecting DNA strands from damage and degradation. In a study led by Susan Bailey of Colorado State University, researchers tracked the length of each twins’ telomeres before, during, and after Scott’s yearlong spaceflight.

The researchers found that Scott’s telomeres significantly increased in length while he was in space, which was not the case with his Earth-bound brother Mark, whose telomeres remained relatively stable. Previous research has shown that longer telomeres are associated with fewer age-related problems.

Though Scott’s telomeres were found to lengthen while he was in space, postflight measurements showed that the telomeres underwent rapid shortening within about 48 hours of landing back on Earth. Eventually, they returned to their preflight lengths. The team believes that the temporary lengthening of Scott’s telomeres could be a side effect of his rigorous exercise routine and restricted, low-calorie diet.

#2 – Decreased body mass and increased folate in orbit

A study conducted by Scott M. Smith of the NASA Johnson Space Center monitored the biochemical profiles of each twin to identify any changes. To do this, his team tracked the brothers’ heights and weights and analyzed their blood and urine samples throughout the duration of the mission.

The researchers not only found that Scott’s body mass noticeably dropped during his time in space, but also that his levels of folate — a beneficial form of folic acid often used to treat anemia — significantly increased.

Much like Bailey’s findings on telomere lengthening, Smith believes the drop in body mass and increase in folate could simply be a result of eating healthier and exercising more often.

#3 – Mentally fit in space, foggy back on Earth

Mathias Basner of the University of Pennsylvania conducted a study that monitored the cognition of both twins over the duration of the mission. By requiring each twin to perform ten different cognitive tests multiple times (preflight, inflight, and postflight), the researchers were able to track how spacefaring Scott’s mental faculties were affected by microgravity.

Using the preflight test results as a baseline, Basner found that Scott’s yearlong mission aboard the ISS did not significantly impair his cognitive abilities while inflight. However, when Scott returned to Earth, the researchers did detect a more pronounced decrease in his speed and accuracy on cognitive tests.

The researchers believe that readjusting to Earth’s gravity may be the cause of Scott’s postflight cognitive decline, but further study is needed to confirm. They also point out that Scott’s performance could have suffered when returning to Earth as the result of a very hectic postflight schedule.

#4 – Flu vaccine stimulates immune system, even in space

To investigate how space affects a human body’s immune system, Emmanuel Mignot of Stanford University conducted a study that introduced the flu vaccine to Scott and Mark on two separate occasions spaced one year apart — during preflight and postflight.

On both occasions, after the vaccines were administered, the twins displayed similar increased immune cell responses to the flu. When the human body is vaccinated against the flu, weakened or dead flu virus cells are injected into the bloodstream. This triggers the body to produce antibodies that seek out and destroy the viral cells, thus preventing any healthy flu cells from multiplying and overwhelming the body’s defenses.

Because the twins showed similar immune responses to both vaccinations, the researchers concluded that being in space does not prevent the flu vaccine from producing the desired immune response.

#5 – Inflammation increases while in space

Mike Snyder of Stanford University carried out a study that investigated whether or not space affects inflammation in the human body. Using blood tests to measure lipids (fats) and cytokines (proteins in the blood that serve as well-known indicators of inflammation), Snyder was able to compare how the inflammatory responses of the brothers differed while Scott was in space.

In this study, the researchers found multiple lines of evidence suggesting that Scott’s body was more prone to inflammation in a microgravity environment than Mark’s was on Earth. For one, the researchers found that Scott had altered levels of a lipid panel taken in space, indicating increased inflammation in his body. The researchers also noted that a certain group of Scott’s cytokines were found to be elevated before the flight, and they remained elevated throughout the mission. Furthermore, another group of Scott’s cytokines spiked just after he returned to Earth. This group of cytokines remained elevated for six months.

Additionally, the study showed that Scott’s body experienced an increase in some proteins that are known to help regulate normal insulin activity. Since inflammation can cause insulin resistance, the increase in Scott’s proteins may have been a counter-measure executed by his body to help combat the insulin resistance associated with inflammation.

#6 – Space affects the microbiome

Inside of each of our guts lives a vast community of microorganisms, known as the microbiome, which plays an important role in our overall health. To study how living in a microgravity environment impacts the microbiome, Fred Turek of Northwestern University monitored the state of each twin’s microbiome before, during, and after the yearlong mission.

The researchers found that the microbiomes of both Scott and Mark were drastically different at all times throughout the project, but the differences were somewhat expected considering microbiomes are very sensitive to environmental variances such as diet and individual immunity. However, the researchers point out that Scott’s microbiome was different in space than it was preflight, displaying a decreased presence of one branch of bacteria known as Bacteroidetes. However, these changes did not persist upon Scott’s return to Earth.

Even though the study showed that Scott’s microbiome changed when switching settings between Earth and space, the changes that were observed were similar to those that would be expected if someone on the ground significantly modified their diet or was exposed to a new environment.

#7 – Spaceflight can trigger gene mutations

Chris Mason of Weill Cornell Medicine used the Twins Study as an opportunity to investigate how space travel can influence genetics. By looking for chemical changes in RNA and DNA through the use of whole-genome sequencing, the researchers showed that Scott experienced hundreds of unique gene mutations compared with his twin.

Though some distinct gene mutations were to be expected, even in twins, the sheer amount of changes surprised the researchers. A few of the gene changes, which were discovered only after Scott returned to Earth, were even found on cell-free DNA and RNA that was circulating in his bloodstream. The researchers believe that these gene changes resulted from the stresses of space travel, which can alter the biological pathways within cells, causing them to eject DNA and RNA. These free-floating DNA and RNA molecules can then trigger the production of new fats or proteins, or even turn specific genes on and off. Though 93 percent of the genes that expressed themselves differently while Scott was in space returned to normal postflight, the researchers found a subset of several hundred “space genes” that remained disrupted after his return.

Of the many gene-induced changes Scott’s body experienced, the researchers found five to be of particular relevance for future missions: (1) Hypoxia, which was likely caused by a lack of oxygen and a surplus of carbon dioxide; (2) Mitochondrial stress and increased levels of mitochondria in the blood, which suggests damage was done to the “power plants” of cells; (3) Telomere lengthening, DNA repair, and DNA damage, which could be a result of living a healthy lifestyle while constantly exposed to radiation; (4) Decreased collagen production, blood clotting, and bone formation, which was likely a combined result of living in microgravity and of fluids shifting around within the body; and (5) Hyperactive immune activity, which may be an effect of living in a new environment.

#8 – Living in space changes how genes are expressed

Similar to the previous project, Andy Feinberg of Johns Hopkins University conducted a study that tracked how each of the twins’ epigenetics (the way that genes express themselves) differed based on their environment.

In two separate populations of white blood cells, Feinberg found multiple regions of the genome where DNA methylation — the process responsible for turning genes on and off — had occurred. These chemical modifications to Scott’s genome were found near two interesting regions. One was close to a gene known to help regulate telomere growth, and another was found near a gene related to collagen production.

Although Scott did experience epigenetic changes during his time in space, the researchers found that the majority of changes were within the expected range of variability for his twin on Earth. However, the results related to telomere growth and collagen production are consistent with the findings of other Twins Study projects.

#9 – Artery walls thicken while in space

Stuart Lee of KBRWyle at NASA Johnson Space Center’s Cardiovascular and Vision Lab performed a study on how inflammation and oxidative stress (damage by free radicals in the air) can impact the structure and effectiveness of arteries. To do this, the researchers examined the twins’ arteries using ultrasound, as well as collected blood and urine samples throughout the mission.

Both during and immediately after the mission, the researchers found that Scott’s inflammation biomarkers were elevated and that the wall of his carotid artery was thicker than it was preflight. Neither of these changes were seen in Mark during his stay on Earth.

At this point, the researchers do not know whether the thickening of Scott’s carotid artery is a temporary and reversible adaptation to living in space, or if it is evidence of permanent and premature arterial aging. Further study is needed to put these findings into clearer focus.

#10 – Proteins that regulate fluids increase while in space

In order to investigate how spaceflight impacts the body’s ability to form and modify proteins, Brinda Rana of the University of California carried out a study that collected urine samples from Scott and Mark before, during, and after the mission. This allowed Rana to identify certain biomarker proteins that are associated with space-related bodily changes, such as muscle and bone loss, metabolic and cardiovascular changes, and the altered regulation of fluids within the body.

The researchers found that while Scott was in space, he excreted some proteins at different concentrations than his Earth-bound brother Mark. In particular, Scott had elevated levels of a protein called aquaporin 2, which helps form the pathways used to carry water through cell membranes in the kidneys. Because aquaporin 2 helps regulate how water is transported within the body, it also serves as a valuable indicator of a body’s overall hydration status.

Notably, the researchers also found that Scott’s increase in aquaporin 2 during spaceflight was correlated with higher levels of plasma sodium — an indicator of dehydration. Though further study is needed, the researchers believe that the increase in aquaporin 2 and plasma sodium may be tied to fluids shifting throughout Scott’s body while he was in a microgravity environment. This is important because, as has been documented with other space-bound astronauts, fluids tend to migrate to the head, causing visual impairment and intracranial pressure.

What’s next?

By taking advantage of an extremely unique opportunity, NASA’s Human Research Program has carried out the first genomic evaluation of the potential risks the human body faces during extended periods of spaceflight. While the results of NASA’s Twins Study are far from conclusive — the sample size is one set of twins and not every variable was strictly controlled for — the study does provide researchers with a wealth of data to guide future studies on the risks of human spaceflight.

As NASA said in a press release, “observations guide development of future hypotheses,” and NASA’s Twins Study has taken the first step to observing how our genomic blueprint is affected by long-term exposure to microgravity and an increased radiation environment. With the information collected as part of this medley of studies, NASA has the preliminary data it needs to inform countless more projects for years to come.

In the meantime, make sure to check back later this year when NASA releases its Twins Study summary paper, which will integrate the results from all ten of the individual studies. Shortly thereafter, each individual study will be releasing its own companion paper.

This post originally appeared in Astronomy.com.

Continue Reading
Advertisement
Click to comment

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

Health

A “Zombie Gene” in Elephants Could Protect Them From Cancer

(Credit: Gregory Zamell/Shutterstock)

Millions of years ago, a gene in mammals became useless. Now scientists have discovered the gene has come back to life in elephants, where it’s exceptionally good at killing damaged cells. The “zombie” gene may explain why the long-lived pachyderms rarely develop cancer and how large animals evolved.

A Cancer Mystery

Elephants are a paradox for scientists. The giants appear largely resistant to cancer, which is odd as their long lifespans and humongous size ought to make them highly susceptible to the disease. The thinking goes that the longer one lives, the more time the body has to pick up cancer-causing mutations. Likewise, big bodies have more cells than small ones. Since all cells are equally vulnerable to damage, more cells mean higher risk for developing the condition. Elephants are guilty on both counts, yet the behemoths get cancer far less than scientists expect.

Vincent Lynch, a geneticist and evolutionary biologist at the University of Chicago in Illinois, wanted to know what gives elephants this cancer immunity. He figured long-lived, sizable animals like elephants must have evolved a way to protect themselves from the disease.

So, he and his team probed the genomes of more than 50 long-living mammals that run the gamut of animal body sizes from bowhead whales to bats, voles and naked mole rats. Their analysis revealed that elephants, as well as manatees and hyraxes, have seven to 11 extra copies of a gene called LIF, whereas every other animal they investigated has only one.

LIF6, the Zombie Gene

In most mammals this single copy of the LIF gene can help prevent cancer development under the right circumstances, so elephants’ numerous duplicates seem like a boon. But it turns out that most of these extra LIF genes don’t do anything anymore.

“We found that elephants and their relatives have many non-functioning copies of the LIF gene,” Lynch said in a statement. But “elephants themselves evolved a way to turn one of these copies, LIF6, back on.”

The researchers had shown in previous work that elephant’s cells are highly sensitive to DNA damage. So, to figure out if LIF6 might play a role, the team stressed the cells with carcinogens. Although LIF6 is normally turned on at very low levels, when DNA damage occurs, it gets expressed at much higher rates. That activates a series of reactions that lead to cellular suicide in the potentially cancerous cells, the team reported August 14 in the journal Cell Reports.

“The elephant cells just died; they were entirely intolerant of DNA damage in a way their relatives’ cells were not,” Lynch said. “Because the elephant cells died as soon as their DNA was damaged, there was no risk of them ever becoming cancerous.”

When the team put the gene into other animals’ cells growing in petri dishes, those cells also died. That makes LIF6, the zombie gene that came back from the dead to kill weak cells, a potential cancer-fighter in other species besides elephants as well.

The work also begins to solve the mystery of elephant’s large size and long lifespan. An evolutionary comparison of LIF6 in elephants, mammoths and mastodons revealed LIF6 came back to life in elephant ancestors around the same time the animals became giants, meaning the gene may have played a role in allowing animals to evolve large bodies.

Continue Reading

#Parasites

@cooper_m He's from a well known hurling stronghold. Fk him. Fk them all #parasites #HurlingToTheCore #Stand4Truth

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