The research, published Sept. 30 in the journal PLOS One, found that rats exposed to levels of radiation similar to what an astronaut might experience on a long-term trip to Mars developed more scar tissue around the small blood vessels of their hearts than rats that were not exposed to this radiation. This scar tissue is indicative of a condition known as cardiac fibrosis, which is known to increase the risk of heart failure.
This scar tissue was observed nearly a year after the rats were first exposed to the radiation.
But since this study was in rats, it cannot definitively say whether this effect will play out in humans. For example, given that humans have a longer life expectancy than rats (80 years versus 2 to 4 years), the effects seen in rats may take around 30 years to show up in humans. However, the study authors say the research highlights the importance of following astronauts' health long after they return to Earth.
"The message that we try to convey … is that the follow-up time is really important," study co-author John Baker, a professor of surgery in the Radiation Bioscience Laboratory at the Medical College of Wisconsin, told Live Science. "When astronauts come back to the Earth, they expect — and we expect — that they're going to live for a long time. I think we have to be wary that they could well develop at least some type of cardiac disease."
How space radiation affects the heart
The link between exposure to radiation and cardiac issues has been well documented. However, "no astronaut has ever been exposed to galactic cosmic radiation for long periods of time," Baker said, which makes it difficult to determine exactly how space radiation affects the heart.
Although Baker and his team previously pinpointed cardiac issues among rats exposed to radiation, this new study utilized NASA's Simulated Galactic Cosmic Ray Simulation (SimGCRSim). This new simulator provides a more precise comparison of the levels of space radiation an astronaut might experience while exploring deep space for more than a year.
During the study, the researchers exposed rats to several minutes of radiation proportionate to their size, similar to what they might experience on a trip to Mars and back (a roughly 18-month round trip, with current technology). Some of the rats' hind legs were suspended, to "simulate conditions of weightlessness," Baker said.
After 360 days, the rats that were exposed to cosmic radiation developed twice as much scar tissue around the heart's small blood vessels than unexposed rats. This buildup of scar tissue means "the heart can't relax to the point when it needs to," thereby increasing the risk of heart failure, Baker said.
This effect was not seen in the rats who were exposed only to simulated weightlessness, confirming "it was only the radiation that produced the damaging effect on the heart," Baker said. However, long-term testing revealed that this group of rats had lower levels of key immune cells, suggesting that microgravity also may affect aspects of long-term health. (Numerous studies have shown various short-term health impacts related to microgravity.)
This study "is a very valuable contribution to space biology," Rupak Pathak, an associate professor of pharmaceutical science at the University of Arkansas for Medical Sciences who was not involved in the study but holds a doctorate in radiation biology, told Live Science. While rats and humans have clear differences, "they share more than 90% of genetic information," he said, as well as very similar cardiac systems.
Given that the study authors were able to expose the rats to radiation only once, Pathak would like to see further experiments exploring whether chronic radiation exposure affects the function of the heart and other vital organs.
Baker and his colleagues hope that future experiments can be used to help NASA implement safeguards for astronauts on long-term missions, such as providing astronauts heart medications or improving shielding for the spacecraft.
"The more we know before we start, then the better NASA is going to be at working out what types of countermeasures can be developed," said Baker.
'> Mars-bound astronauts could face years of heart scarring, rat study hints "He lived with a chronic urogenital infection," study lead author Natalia Berezina, an anthropologist at Lomonosov Moscow State University in Russia, told Live Science in an email.
"It was not a brief episode," she said. "His last years were probably marked by considerable and more or less constant pain."
Berezina and colleagues investigated a small, stone-like object found in an Early Bronze Age burial in the Stavropol Upland region of southwestern Russia. They published their findings Sept. 30 in the journal Archaeological and Anthropological Sciences.
The burial was part of a kurgan cemetery, an ancient steppe funeral tradition that involved constructing a large mound of dirt over a grave. Archaeologists discovered a catacomb when they excavated the mound, and inside was the skeleton of a man who was in his 40s when he died around 5,300 years ago. The researchers found a flint arrowhead near the man's pelvis.
But during a laboratory analysis after the skeleton was excavated, researchers noticed an odd stone-like object in the collection of hand bones. The brownish object was round with several protrusions and measured about 0.8 inches (2.1 centimeters) in diameter, or roughly the size of a grape. A small crack in the object showed a crystal-like structure inside.
To learn more, the researchers used several analytical methods to determine what the tiny object was made of. First, X-ray fluorescence analysis revealed that the main components of the object were calcium and phosphorus. Then, they used X-ray powder diffraction analysis to identify the crystal structures.
In addition to common minerals, the researchers discovered the presence of whitlockite, a rare calcium salt that is known to occur in kidney, bladder and prostate stones. These "stones," collectively called calculi, are hard masses of minerals, such as calcium-containing salts. They differ in terms of the organ they form within, the exact mechanism of how they form, and their chemical makeup, although kidney and bladder stones tend to contain very similar compounds.
Whitlockite is strongly associated with bacterial infections in the human body, which suggests that the Bronze Age man had a chronic infection that resulted in the stone, the scientists concluded.
"On the balance of the available evidence, we regard a renal [kidney] stone secondary to chronic upper urinary tract infection as the most probable origin," the researchers wrote. That is, the man dealt with chronic or recurrent UTIs, which led to the formation of the stone and likely caused him considerable discomfort. UTIs can contribute to the formation of kidney stones by altering the acidity of urine and making minerals more likely to accumulate.
The researchers aren't sure why the man had urinary tract issues or whether it contributed to his death.
Notably, kidney stones can sometimes travel to the bladder, so it's unclear exactly where the stone was in the man's body when he died. If the stone had obstructed the man's ureter — one of the two long tubes that connect the kidneys to the bladder — it may have caused kidney swelling, a secondary infection or sepsis. These conditions were frequently fatal prior to the invention of antibiotics.
Other possibilities for what caused the stone include a bacterial infection of the man's prostate gland or even a sexually transmitted infection.
The man was likely on the move frequently within this Early Bronze Age steppe society, and other injuries to his skeleton suggested he had a physically demanding life, the researchers wrote. His bones showed that he was well muscled but was also dealing with degenerative joint disease in his spine, shoulders, hips, hands and feet. He had a series of healed fractures in his right shoulder, ribs and forearm.
"These were people who worked with cattle and heavy wagons on the open steppe," Berezina said, "and the injuries that follow from that are the injuries we find." In a previous study at a nearby cemetery, Berezina and colleagues found the skeleton of a man who was injured when a wagon ran over him, several years before his death. "Against that background, four healed fractures in our man look unremarkable," she said.
But the urinary tract stone would have made the man's life difficult, the researchers noted. "This individual suffered from a painful and debilitating chronic urogenital infection, a condition that would have significantly impacted his quality of life," they wrote.
What do you know about the bones in your body? Test your knowledge with our human skeleton quiz.
'> 5,300-year-old kidney stone the size of a grape found in Bronze Age man's burial near Black Sea In the new research, published Monday (Nov. 2) in the journal PNAS, the scientists said they identified microscopic structures resembling red blood cells alongside chemical signatures of heme, the oxygen-carrying component of hemoglobin.
The new findings come from limb bones of a roughly 10-foot-long (3 meters) dinosaur called Aratasaurus museunacionali. While previous research has detected blood in dinosaur fossils, this is the first study to use chemical processes to identify heme-based signatures in dinosaur bones.
"Traditionally, fossils give us information through bones, teeth, shells and morphology. But exceptionally preserved fossils may contain another archive of information: microscopic structures and molecular traces of the original organism," study co-author Kliti Grice, a professor in the School of Earth and Planetary Sciences at Curtin University in Australia, told Live Science via email. "That opens the possibility of asking questions about ancient biology that skeletal anatomy alone cannot answer."
Deep in the bones
The team was not originally looking for traces of dinosaur blood, Grice said. Her research was driven by a broader question: How much of an ancient organism's original biology can survive fossilization?
To investigate, Grice and her team studied the limb bones of A. museunacionali, an extinct species of small theropod that lived during the Early Cretaceous period in Brazil. Theropods were a group of mostly meat-eating dinosaurs that walked on two legs. They included famous predators such as Tyrannosaurus rex and Velociraptor.
Using microscopic and chemical analysis on the theropod's limb bones, the researchers found numerous microscopic structures within vascular canals, channels that once carried blood vessels through the bone. Their shape, size and location were consistent with red blood cells, the team said.
"We combined microscopy, mineralogical analyses and molecular geochemistry," Grice said. "Critically, we investigated the chemistry in situ [in the bone itself], so we could relate the chemical signals to the microscopic structures in their physical context within the fossil. That is much stronger than simply extracting molecules from a piece of fossil and assuming where they originated."
The team's chemical analyses detected preserved heme-related compounds associated with these structures, providing more chemical evidence to support the idea that the finding could be traces of dinosaur blood, as heme is the iron-containing, ring-shaped molecule that forms a key part of the molecule hemoglobin in red blood cells.
A time capsule
Grice and the team think the conditions the theropod dinosaur was buried in could have helped preserve the vascular structures and the red blood cells within them. They suggested that the animal was rapidly covered by sediment in a low-oxygen environment containing microbial mats — thin biofilms made of microorganisms. These conditions may have altered the normal process of decomposition, helping to preserve the microscopic structures and associated chemical signatures.
An illustration of a microbial mat covering A. museunacionali's bones after it died. (Image credit: Victor O. Leshyk)"The red-blood-cell-like structures were mineralised with hausmannite, a manganese oxide mineral (Mn₃O₄)," Grice said. "We think early mineralisation helped stabilise or replicate microscopic biological structures before they were completely destroyed, while aspects of the associated chemistry also survived in altered form."
The fossil also contained preserved amino acids associated with collagen, the structural protein found in bone.
Not everyone is convinced
While blood has been found in dinosaur fossils before, not everyone agrees that these latest findings are truly red blood cells.
"I very much appreciate this team bringing rigor to the study of deep time fossils," said Mary Schweitzer, a molecular paleontologist at North Carolina State University who was not involved in the study but has previously studied soft tissues from the dinosaur age. "I am in agreement that endogenous [produced within the body] molecules can persist over geological time in some form, and that there is much these can teach us. However, I am not convinced that the images they figure are remnant RBCs [red blood cells] for several reasons."
For one, the structures do not convincingly match the expected appearance of red blood cells in nonmammalian animals, Schweitzer said. Unlike mammalian red blood cells, which lose their nuclei during development, those of birds and reptiles retain their nuclei. This typically produces a characteristic nuclear bulge in the shape of the cell.
According to Schweitzer, the latest findings show the microstructures having more of a concave shape with no nuclear bulge. The structures also were smaller than most non-mammalian red blood cells, "so morphological similarity is not met," Schweitzer said.
"I appreciate these authors bringing technological innovations to the study of dinosaur fossils," she said. "I am excited to see that this team and others are moving forward with a molecular approach to ancient fossil remains."
Editor's Note: This article was updated at 5:44 p.m. E.D.T. to remove an outside comment that suggested the study did not include resonance Raman spectroscopy. The team did perform that analysis.
'> Traces of ancient blood found in 115 million-year-old dinosaur fossil, new study claims , it was the sacred home of Wadjet, the cobra goddess of Lower Egypt, and one of the most
in the pharaonic landscape.
Archaeologists have excavated its upper layers for decades, finding remains from the rule of the Macedonian Ptolemaic dynasty (305 to 30 B.C.) and Roman era (30 B.C. to A.D. 395). But the deeper, older layers at the site — including a mound called Kom C, sitting below groundwater level in waterlogged delta clay — had stayed stubbornly out of reach. Kom C itself rises above the surface as a visible mound, but earlier excavations had reached only the Ptolemaic and Roman layers before hitting the water table.
Now, researchers have turned to noninvasive tools, including satellite imagery, to delve into the mysterious subterranean layers.
To learn more without disturbing the site, the team ran 15 parallel lines of electrical resistivity tomography (ERT) across an area of roughly 58,100 square feet (5,400 square meters). This technique reveals the underground landscape by passing electrical currents through the earth, measuring how they travel and creating a map that archaeologists can read.
The picture that came back was layered. Between the surface and 10 feet (3 m) down, the team found scattered Ptolemaic and Roman debris, including displaced mudbricks, pottery shards and broken limestone, which point to centuries of continued occupation and rebuilding on the site. Later residents dismantled older structures for reuse and left a scatter of displaced material behind.
Deeper still, between 10 and 20 feet (3 and 6 m), the researchers found a large mudbrick structure from the 26th dynasty (688 to 525 B.C.), also known as the Saite period. They were able to date this discovery based on its layer, the unique shape of the mudbricks and other artifacts such as pottery, which the team dated by style and their archaeological layer, with carbon-14 dating applied to associated organic material. The large structure may be a tomb, a house for priests or a religious shrine, the team wrote in the study, published in March in the journal Acta Geophysica.
And below that, at 20 to 23 feet (6 to 7 m) underground, the researchers unexpectedly found a thick, clean layer of sand.
That sand is the discovery within the discovery, the team wrote in the study.
"By combining satellite radar with deep ERT profiles, we didn't just map the walls of this massive Saite-era structure — we were also able to analyze the subsurface layers," study co-author author Abdelaziz Elfadaly, an associate research professor at Egypt's National Authority for Remote Sensing and Space Sciences, told Live Science. "The detection of a significant, clean sand foundation layer beneath the mudbrick walls explains how these heavy structures survived the high water table and shifting clayey soil of Buto."
The sand layer, in effect, acts as a barrier; it stops groundwater from wicking upward into the mudbrick, which would soften and dissolve it. The sand also lets water drain sideways instead of pooling against the foundation, according to Elfadaly.
A 3-by-3 foot (10 by 10 m) excavation trench that was around 20 to 23 feet (6 to 7 m) deep confirmed the presence of thick mudbrick walls resting on that sand layer, and nearby, a spread of objects that hint at the site's sacred function. According to Elfadaly, these finds included ushabti and shawabti figurines — small servant statues typically placed in tombs to serve the deceased in the afterlife — and a limestone altar whose carved channels bore dried residues consistent with animal blood, pointing to offering rituals performed at the site. The study also noted a rarer find: a faience baboon figurine, the kind associated with Thoth, the god of wisdom.
"A monumental building of this scale underscores the Saite pharaohs' intense commitment to glorifying the Delta region," Hussein Bassir, director of the Antiquities Museum at a cultural research center known as Bibliotheca Alexandrina who wasn't involved with the study, told Live Science in a WhatsApp message. "Using pure sand as a stabilizing cushion was a brilliant, deliberate tactic — the ancient builders profoundly understood their environment."
The team is planning a return visit, this time using wider-spaced electrical resistivity surveys to reach deeper layers, along with specialists who study ancient plants and also understand how geological features changed over time, which may help reconstruct what the landscape around Buto looked like when these walls were first laid.
'> Buried for 2,600 years beneath Nile mud, a massive ancient Egyptian complex was just found — from space
The idea is not new. It's been discussed in the past, but it was difficult to get a consensus on what goes in and what should not go in. That's still going to be tricky, but at least there's a broad acknowledgement that the time is ready to start introducing biology into the DSM.
It's very likely that, at the end of it, there will be meaningful changes in a positive kind of way. It's not going to make everyone happy. There are going to be gaps, but the idea is to incrementally improve this and make it more modern as we go along.
KHC: What sort of biological markers have you seen that we can actually correlate with these disorders?
AK: What the committee is doing is taking a more nuanced approach. Outside the realm of Alzheimer's disease, which I'll get into in a minute, there are no clear-cut diagnostic biomarkers — meaning no blood tests or brain scans that you can look at and say, "This person has a diagnosis of depression," or "This person has PTSD," or "This person has schizophrenia."
The committee talked about how, in addition to biological biomarkers, there's a concept of biological factors. What I mean by that is biological pathways and mechanisms that have a role in the development of a particular disorder, but the findings have not crystallized into a laboratory test.
For example, immunology — the study of the body's response to a variety of stresses, including infections and others — has been shown to be impactful in about 30% of cases of major depression. Yet there is no single biological laboratory test that is currently available that can be used [to diagnose immune-mediated depression] in clinical practice. So these come under the category of what we call biological factors.
In the Alzheimer's disease field there are clear-cut biomarkers. There are now blood tests for proteins called tau and amyloid that have been approved by the FDA [Food and Drug Administration] as biomarkers for Alzheimer's disease. Meaning, if you have a clinical picture and a mental-status exam consistent with intellectual decline, you must have a positive biomarker test to be categorized as having definitive Alzheimer's disease.
And that's new. Ten or 15 years back, there were brain scans, and if you did a lumbar puncture, you could find these proteins in the spinal fluid. But those are invasive. Now you actually have a blood test.
A neuron, in blue, is surrounded by a plaque of amyloid-beta protein, in yellow, which causes the symptoms of Alzheimer's disease. Tests can be used to detect biomarkers for Alzheimer's disease. (Image credit: JUAN GAERTNER/SCIENCE PHOTO LIBRARY via Getty Images)But that degree of precision, for lack of a better term, is not available in the other branches of psychiatry. Nonetheless, there are clues that other pathways and mechanisms are involved.
I mentioned immunology as one. Another big elephant in the room is genetics.
Most people think of genetics as an abnormal gene or a mutation — meaning a gene switches or changes and confers increased risk — as one mutation causing one disease. That's how most people in the general public think about mutations: They cause disease.
But when you get into complex diseases like heart disease and diabetes, there are multiple genes involved. And diseases may or may not be caused by a gene. Abnormal genes may or may not cause the disease, but they increase risk.
With mental disorders, the situation becomes immensely more complicated. It's not just a few genes here and there. There are hundreds of genes, each increasing the risk for depression, schizophrenia and anxiety disorders by a small amount.
So while there is no single genetic test that can now be used, large numbers of genes have consistently been shown — and many of the recent studies are strong — to be associated with certain disorders. But because there's no single gene or small group of genes, we cannot walk away from the science. Complexity doesn't mean we throw our hands up and say, "Well, it's all too much."
It may seem overwhelming, but genetic profiles are better understood today than they were 20 years ago. So that's something else this committee is thinking about and I think should take into account going forward: to somehow incorporate that into the diagnostic categories.
KHC: Do you think there's any sort of risk with adding those biological factors into the DSM?
AK: I don't think so, because if you think about genetics, it's not going to be introduced as a biological test.
Most folks know that mental disorders, like other medical disorders, run in families. And genetics is the most plausible explanation for that. What this does, I hope, is introduce a degree of more comprehensive description of these disorders. So when a busy clinician looks at it, it confirms what they already suspected: There's a family history here, and family history means genetics.
It's complex, many genes are involved, and it produces a better characterization of this. The diagnosis is still going to remain clinical, but this provides a biological context, very much like, say, diabetes or heart disease.
Genes and environment cause a variety of medical disorders. With heart disease, there's no one gene. When cardiologists develop a risk profile for heart disease, it includes genes, other physiological factors such as BMI, which is the weight-height ratio, diet and a variety of environmental factors.
That degree of classification is missing today in mental health and psychiatry. We hope this is a first step in correcting, if you will, those conceptions about what causes these disorders.
KHC: How would you end up using this in a psychiatrist's office to guide treatment?
AK: I can give you one possible example. I'm reaching a bit.
There's a term commonly used in clinical psychiatry and psychology called comorbidity. What it means is that people who are diagnosed with depression also have anxiety, or people who are diagnosed with an anxiety disorder also have substance abuse or alcoholism in general.
That is not coincidental. It's not something that we just somehow find. A lot of these disorders share genes.
For example, about 45%, roughly, of patients diagnosed with a major mood disorder also have an anxiety disorder. And you flip that around: About 45%, roughly, of patients diagnosed with an anxiety disorder — it could be generalized anxiety disorder, what we call PTSD, or a phobia — also have a mood disorder.
Patients with anxiety may also be diagnosed with a mood disorder. (Image credit: MementoJpeg via Getty Images)I think when clinicians classify them together, not as the same disorder but as sharing a lot of psychological as well as genetic risk, clinicians should be on the lookout for both. A patient with a mood disorder, for example, could either now or at some later point develop an anxiety disorder. Or someone with an anxiety disorder is at risk for substance abuse.
So treatments need to be tailored a little more broadly. I'm hoping that'll be something clinicians think about when they talk to patients and their families.
KHC: What do you think is the most unique aspect, from your perspective, of this upcoming DSM-6?
AK: My bias is the biology. I say this because a lot of the other things, the cultural factors, etc., are largely appreciated, and they'll be better characterized. Some things like cognitive changes, such as working memory and attention [tests], are not unique to any given disorder.
Exclusive to Live Science Pro
Biology will be qualitatively new when introduced into the DSM, and I hope it's done well. I hope that they do it appropriately, and I think they will [do it] correctly.
It's not going to be perfect, but it's going to be a first step. I think introducing the idea that genetics, immunology and other factors are very important in the causation of mental disorders, and explain some of the phenomena that we previously could not find an explanation for, is — I hate to use the word "leapfrog" — but that's kind of what it is.
It moves the field conceptually forward, and not as a slow, steady, gradual increase. For the DSM, it would be an important step forward.
This interview has been condensed and edited lightly for clarity.
Help us improve Live Science Pro: We're always trying to make our content better. Leave us feedback about Pro here.
'> 'Now you actually have a blood test': Psychiatry's bible, the DSM, is getting upgraded to include biological markers. A psychiatrist explains what...