Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




SPACE MEDICINE
Orbital samples with sight-saving potential
by Staff Writers
Houston TX (SPX) Dec 16, 2013


Expedition 33 flight engineer Akihiko Hoshide of the Japan Aerospace Exploration Agency performs ultrasound eye imaging in the Columbus laboratory of the International Space Station. Human research adds to model animal studies to build knowledge of eye health during spaceflight. Credit: NASA.

Those who travel to space are rewarded with a beautiful sight - planet Earth. But the effects of space travel on the human sense of sight aren't so beautiful. More than 30 percent of astronauts who returned from two-week space shuttle missions and 60 percent who spent six months aboard the International Space Station were diagnosed with eye problems.

Two recent investigations examined mechanisms that may explain eye changes in spaceflight, help find ways to minimize this health risk to astronauts and eventually prevent and treat eye diseases on Earth.

Mice were flown aboard shuttle flights STS-133 in March 2011 and STS-135 in July 2011 as part of the Commercial Biomedical Testing Module-2 (CBTM-2) and CBTM-3 investigations into how space affects muscle and bones. These sets of mice found second life, contributing to other studies through a tissue-sharing program. Two studies used eye tissue from the mice to provide the first direct evidence that spaceflight causes cellular-level damage that has the potential to cause long-term vision problems.

Susana Zanello, Universities Space Research Association scientist at NASA's Johnson Space Center in Houston, examined eye tissue for changes in gene expression in the retina-the sensory tissue at the back of the eye. That study is the subject of a paper, "Spaceflight Effects and Molecular Responses in the Mouse Eye: Preliminary Observations after Shuttle Mission STS-133," recently published in Gravitational and Space Research.

Results from a study of mice from the second flight were detailed by Xiao W. Mao, MD, a researcher in the Division of Radiation Research at Loma Linda University and Medical Center in California, and her colleagues in "Spaceflight Environment Induces Mitochondrial Oxidative Damage in Ocular Tissue," published in Radiation Research.

Both studies implicated oxidative stress in eye damage. Spaceflight exposes astronauts - and mice - to radiation, hypothermia, hypoxia and variations in gravity, all of which may play roles in tissue injury, and, in particular, oxidative stress. Oxidative stress reflects an imbalance between the reactive oxygen that is generated by normal cell metabolism and the cell's ability to handle toxic byproducts from that metabolism.

The imbalance created by oxidative stress produces peroxides and free radicals, which contribute to a number of degenerative conditions, including aging. They also are known to cause damage to DNA, proteins, cell membranes and organelles inside cells.

These organelles include mitochondria that convert oxygen and nutrients into energy. Mitochondria are particularly sensitive to oxidative stress and, therefore, to the effects of microgravity and radiation in space. Mitochondria are thought to play an important role in damage to the retina and have been linked to age- and disease-related eye problems.

Mao's study examined mitochondria-associated gene expression in the mouse eye tissue and found significant changes in several genes involved in oxidative stress response. "We measured 84 genes and found nine that are really critical for developing these changes and associated with damage," she said. "These changes were after short-term flight and might be reversible or might deteriorate over time. But the data so far do indicate a risk to astronauts from oxidative changes."

In the STS-133 samples, Zanello found increased expression of genes involved in response to oxidative stress in retina tissue. "We saw this effect immediately after landing, which means it was a defensive increase in response to oxidative stress," she said. Also notable was that a week after spaceflight, the response had decreased, indicating that the damage may be reversible. "That opens the door to the possibility of countermeasures, such as nutritional anti-oxidants," Zanello said.

The Zanello study also reports the presence of two indicators of optic nerve damage, glial fibrilar acidic protein (GFAP) and beta-amyloid. GFAP is known to be elevated by stress and inflammation in the central nervous system and present following retina injury. Studies have found beta-amyloid in tissue following traumatic brain injury and as evidence of optic nerve damage in shaken-baby syndrome.

Both researchers say more work needs to be done to confirm these results and to develop appropriate countermeasures. This follow-up investigation also could use the tissue-sharing program, but researchers say they need a larger number of samples from model organisms that had longer exposure to space.

These investigations move scientists closer to development of countermeasures, such as drugs or dietary supplements, to protect the eyes and vision of astronauts. People on Earth with eye problems related to aging, such as macular degeneration, and diseases, such as diabetic glaucoma, also would benefit. That will mean more people can enjoy beautiful sights, whether in space or on the ground.

.


Related Links
NASA/Johnson Space Center
Space Medicine Technology and Systems






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SPACE MEDICINE
Robots from Space Lead to One-Stop Cancer Diagnosis Treatment
Huntsville AL (SPX) Nov 06, 2013
We may not be driving flying cars to work yet, but that doesn't mean we don't have a lot to be excited about from technology advances related to the space age. Instead of zipping past traffic jams, International Space Station-derived robotic capabilities are giving us a fast pass to life-saving surgical techniques with cancer-fighting finesse. According to the National Cancer Institute, an ... read more


SPACE MEDICINE
China's Lunar Lander May Provide Additional Science for NASA Spacecraft

China plans to launch Chang'e-5 in 2017

Mining the moon is pie in the sky for China: experts

Ancient crater could hold clues about moon's mantle

SPACE MEDICINE
Opportunity Communications Remain Slow Due To Odyssey Issues

New Views of Mars from Sediment Mineralogy

NASA poised to launch Mars atmosphere probe

The Tough Task of Finding Fossils While Wearing a Spacesuit

SPACE MEDICINE
IBM sees five tech-powered changes in next five years

European consortium space company to offer 'affordable' trips to space

Planning group calls for National Space Policy in Britain

Quails in orbit: French cuisine aims for the stars

SPACE MEDICINE
Chinese sci-fi writers laud moon landing

China deploys 'Jade Rabbit' rover on moon

The Dragon Has Landed

Chinaese moon rover and lander photograph each other

SPACE MEDICINE
Altitude of International Space Station raised

NASA mulls spacewalks to fix space station

NASA reports coolant loop problem at ISS

Space station cooling breakdown may delay Orbital launch

SPACE MEDICINE
India to decide December 27 on GSAT-14 launch date

Arianespace orders 18 rockets for 2 bn euros

Iran sends second monkey into space

SpaceX to bid for rights to historic NASA launch pad

SPACE MEDICINE
Astronomers solve temperature mystery of planetary atmospheres

Nearby failed stars may harbor planet

Innovative instrument probes close binary stars, may soon image exoplanets

Feature of Earth's atmosphere may help in search for habitable planets

SPACE MEDICINE
Inertial Sensor Head shaken but not disturbed

Programming smart molecules

SOFS Take to Water

Rock points to potential diamond haul in Antarctica




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement