Tag Archives: microgravity

New changes to the brain found from long space missions

Scientists have discovered a “significant increase” in the brain’s white matter that occurs after astronauts have completed long missions in weightlessness.

The team conducted brain MRIs of 11 astronauts before they traveled to the ISS, and then again one day after they returned. Scans were then performed at several interval across the following year. “What we identified that no one has really identified before is that there is a significant increase of volume in the brain’s white matter from preflight to postflight,” Kramer says. “White matter expansion in fact is responsible for the largest increase in combined brain and cerebrospinal fluid volumes postflight.”

These changes remained visible one year after spaceflight, which the researchers say indicates they could be permanent alterations. Past research has suggested that changes in the volume of cerebrospinal fluid (CSF) specifically could be a key driver of Visual Impairment Intracranial Pressure in astronauts. The authors of the new study also observed an increase in the velocity of CSF through the cerebral aqueduct, along with deformation of the pituitary gland, which they believe is related to higher intracranial pressure in microgravity.

The uncertainties for this work remain very large. For one thing, the sample (11 astronauts) is very small. For another, the permanence of this change is only suggested and remains unproven.

Nonetheless, this research adds to the growing body of research that suggests that long term weightlessness is generally not good for the human body. It also reinforces the desperate need for research into the effects of even a small amount of artificial gravity. To most efficiently design spacecraft that provide some form of centrifugal force as artificial gravity, we need to find out the minimum required. It could be providing only 10% or 30% Earth gravity could be sufficient. Or not. We just don’t know.

The engineering challenges however go up significantly the more gravity you need to create. For future interplanetary travel this information is critical.

Does zero gravity cause intestinal issues?

The uncertainties of science: New research simulating microgravity on Earth now suggests that zero gravity might weaken the walls of the intestines.

The barrier function of the intestinal epithelium, he added, is critical for maintaining a healthy intestine; when disrupted, it can lead to increased permeability or leakiness. This, in turn, can greatly increase the risk of infections and chronic inflammatory conditions such as inflammatory bowel disease, celiac disease, Type 1 diabetes, and liver disease.

McCole’s team used a rotating wall vessel — a bioreactor that maintains cells in a controlled rotation environment that simulates near weightlessness — to examine the impact of simulated microgravity on cultured intestinal epithelial cells.

Following culture for 18 days in the vessel, the team discovered intestinal epithelial cells showed delayed formation of “tight junctions,” which are junctions that connect individual epithelial cells and are necessary for maintaining impermeability. The rotating wall vessel also produces an altered pattern of tight junction assembly that is retained up to 14 days after the intestinal epithelial cells were removed from the vessel.

This is good research, but it has not proved anything, merely indicated an area of research that needs a follow-up in space. I also wonder if there has been any evidence of this phenomenon from astronauts returning from long missions. As far as I know, intestinal issues have never been mentioned as a problem post flight.

Worm grows 2 heads on ISS

The uncertainty of science: For reasons that are not yet understood, a flatworm fragment flown to ISS in a microgravity experiment regenerated with two heads.

But the most dramatic difference was a type of regeneration observed in one of the 15 worm fragments sent to the ISS. That worm returned to the scientists with two heads (one on each end of its body), a type of regeneration so rare as to be practically unheard of — “normal flatworms in water never do this,” Levin told Live Science. When the researchers snipped both heads off back on Earth, the middle portion regenerated into a two-headed worm again.

“And these differences persist well over a year after return to Earth!” Levin said. “Those could have been caused by loss of the geomagnetic field, loss of gravity, and the stress of takeoff and landing — all components of any space-travel experience for living systems going to space in the future,” he said.

The flatworms that flew in space showed other significant differences from the control group that stayed on Earth, further suggesting that for flatworms at least the environment of weightlessness causes more problems that were expected.

ISS twin study suggests weightlessness stresses the body in unexpected ways

The first preliminary results from NASA’s comparison of Scott Kelly, who spent 340 days on ISS, and his twin brother Mark, who did not, suggests that weightlessness stresses the body’s genetic system in ways not previously measured.

Preliminary results are in from NASA’s unprecedented twin study — a detailed probe of the genetic differences between astronaut Scott Kelly, who spent nearly a consecutive year in space, and his identical twin Mark. Measurements taken before, during and after Scott Kelly’s mission reveal changes in gene expression, DNA methylation and other biological markers that are likely attributable to his time in orbit.

From the lengths of the twins’ chromosomes to the microbiomes in their guts, “almost everyone is reporting that we see differences”, says Christopher Mason, a geneticist at Weill Cornell Medical College in New York City. He and other project scientists reported the early results on 26 January in Galveston, Texas, at a meeting of scientists working in NASA’s Human Research Program. “The data are so fresh that some of them are still coming off the sequencing machines,” Mason says.

It remains unclear at this point the medical consequences of these genetic changes. The data from this first experiment is still too preliminary, and it only involves looking at two people, a sample that is obviously too small. Nonetheless, it is a beginning, and of some significance.

The effect of weightlessness on the spine

New observations of astronauts before and after four to seven month long missions to ISS has found the back pain many astronauts experience appears to be caused by significant muscle atrophy.

The MRI scans indicated significant atrophy of the paraspinal lean muscle mass —which plays a critical role in spinal support and movement—during the astronauts’ time in space. The lean muscle, or “functional,” cross-sectional area of the lumbar paraspinal muscles decreased by an average of 19 percent from preflight to immediate postflight scans. A month or two later, only about two-thirds of the reduction had recovered. There was an even more dramatic reduction in the functional cross-sectional area of the paraspinal muscles relative to total paraspinal cross-sectional area. The ratio of lean muscle decreased from 86 percent preflight to 72 percent immediately postflight. At follow-up, the ratio recovered to 81 percent, but was still less than the preflight value.

In contrast, there was no consistent change in the height of the spinal intervertebral discs. Dr. Chang and coauthors write, “These measurements run counter to previous hypotheses about the effects of microgravity on disc swelling.” Further studies will be needed to clarify the effects on disc height, and whether they contribute to the increase in body height during space missions, and to the increased risk of herniated disc disease.

These results are very encouraging, because they indicate that the back problems seen are mostly attributable to weakened muscles, not actual spinal damage, and can therefore be more easily mitigated by new exercises while in orbit.

Liver damage from weightlessness?

The uncertainty of science: Mice flown for almost two weeks on the last space shuttle mission in 2011 have shown evidence of the early symptoms of liver disease.

The mice spent time orbiting the Earth on the final space shuttle flight in 2011. Once they returned home, teams of scientists were allowed to share and study their internal organs.

Jonscher’s team found that spaceflight resulted in increased fat storage in the liver, comparing pair-fed mice on Earth to those on the shuttle. This was accompanied by a loss of retinol, an animal form of Vitamin A, and changes to levels of genes responsible for breaking down fats. As a result, mice showed signs of nonalcoholic fatty liver disease (NAFLD) and potential early indicators for the beginnings of fibrosis, which can be one of the more progressive consequences of NAFLD. “It generally takes a long time, months to years, to induce fibrosis in mice, even when eating an unhealthy diet,” Jonscher said. “If a mouse is showing nascent signs of fibrosis without a change in diet after 13 ½ days, what is happening to the humans?”

This result doesn’t prove that weightlessness causes liver damage. It only suggests that more research is needed, though the data from six month to year long missions suggest that the liver harm to humans is either non-existent or temporary.

Injected stem cells cure osteoporosis in mice

Scientists have discovered that an injection of stem cells into mice with osteoporosis was able to completely cure them of the bone disease.

Researchers at the University of Toronto and The Ottawa Hospital had previously found a causal effect between mice developing age-related osteoporosis and a deficiency in mesenchymal stem cells (MSCs). One of the promising attributes of MSCs is that, while they can grow into different cells in the body just like other stem cells, they can be transplanted without the need for a match. “We reasoned that if defective MSCs are responsible for osteoporosis, transplantation of healthy MSCs should be able to prevent or treat osteoporosis,” says William Stanford, senior scientist at The Ottawa Hospital and Professor at the University of Ottawa.

To put this reasoning to the test, the scientists injected MSCs into mice with the condition. Six months later, which is one quarter of the life span of the animal, they observed a healthy functional bone in place of the damaged one. “We had hoped for a general increase in bone health,” says John E. Davies, co-author of the study. “But the huge surprise was to find that the exquisite inner ‘coral-like’ architecture of the bone structure of the injected animals – which is severely compromised in osteoporosis – was restored to normal.”

The importance of this discovery for space travel is that it might eventually allow scientists to use it to somehow prevent the loss of bone density during weightlessness.

3D printed items made in space come back to Earth

NASA today released a video of engineers unpacking a box of 3D parts that had been printed on ISS and then returned to Earth for testing.

Some more details here.

The goal, Bean continued, is for NASA to develop a database of mechanical properties to see if there’s any difference in mechanical strength between identical items made in space and on Earth. During the interview last month, Bean said that while NASA didn’t yet have any hard data, there had been initial indications from videos made on the space station, that the plastics used in the 3D printing there had “adhered differently” than those in the terrestrial test. “The astronauts trying to get the parts off the plate,” Bean said, found that the plastic “seemed to be a little more stuck than on the ground.” He said that while it was too early to tell if that was actually true, his guess was that if so, “it may be due to a lack of convection in zero-gravity.”

Understanding the engineering issues of 3D printing in space will make it possible for crews to carry far less cargo on long interplanetary journeys. Instead, they would carry a much smaller amount of raw material, which they could use to manufacture items as needed, then recycled.

How scientists are using the Kelly twins during Scott Kelly’s year-long mission to ISS to learn how weightlessness effects the human body

Link here. Scott Kelly launches today to the station to begin the flight.

The article’s headline and initial focus on how the Kellys’ privacy rights might interfere with the research seems inappropriate. It is as if the author and Nature wanted to spin the story to force the Kellys to reveal private medical data they would prefer to keep private.

The real story the article tells is that an incredible wealth of knowledge about microgravity will be gained by this flight, because the Kellys are both participating. And depending on what is learned when their entire genomes are sequenced, we might also be able to study that fully as well.

A bacteria that causes urinary tract infections has been found to grow better in zero gravity than it does on Earth.

Shades of science fiction: A bacteria that causes urinary tract infections has been found to grow better in zero gravity than it does on Earth.

It was inevitable that such a bug would be found. The key here is to figure out how to keep it from getting up into space.