NASA satellite imaging technology used in fight against diabetes
25 June 2006
Technology that identifies landforms, geology and
vegetation types from satellite images of the earth's surface has been used
to help identify insulin-related structures in electron microscope images of
Scientists at The George Washington University, Washington,
and Cornell University, Ithaca, N.Y., helped modify the NASA technology,
which has greatly increased the speed of the research.
of a sliced rat beta cell that has been processed with the modified
NASA imaging technology. Insulin granules are the dark black spots
surrounded by a white area called a halo. Large cells have hundreds
of insulin granules. The coloured borders around the granules are
labels added to identify them and classify how they appear. Credit:
The team analyzed electron photomicrographs of beta cells from rats. The
hormone insulin, which regulates blood glucose levels, is manufactured in
beta cells in the pancreas. Microscopic structures called granules carry
insulin toward the cell wall of the beta cells, where it is secreted in
response to glucose levels in the blood.
The image analysis technology was
adapted to identify biological structures, the insulin granules, in electron
photomicrographs. The research team observed the number, size, and position
of insulin granules in the beta cells in response to glucose, which cells
use for energy.
"Previously, the analysis of each electron micrograph took
an assistant several hours to complete. Now, with the image processing
software, we can automatically analyze several dozen electron micrographs
overnight," said Tim McClanahan, a scientist at NASA's Goddard Space Flight
Center in Greenbelt, Md.
"NASA technology combined with our modifications
has provided us with new tools for fighting diabetes," said Murray Loew,
director of the Biomedical Engineering Program and professor of engineering
at The George Washington University's School of Engineering and Applied
Diabetes afflicts more than 20 million Americans. It is caused by
the body's inability to regulate glucose. Insulin regulates glucose by
unlocking the interior of cells and allowing glucose in blood to pass
through the cell wall.
Two types of diabetes exist. In Type I diabetes,
pancreatic cells are destroyed. In Type II diabetes, either pancreatic cells
don't secrete enough insulin, or cells in the body lose their responsiveness
to insulin, or both problems happen at once. Both types of diabetes cause
glucose to build up in the blood instead of being delivered to the interior
of cells, where it is needed or would be stored. Life-threatening effects
include coma, heart disease, kidney damage, nerve damage, blindness, and
loss of limbs.
We plan on an extensive collaboration in the future. The
potential for this research is excellent," said Geoffrey Sharp, a diabetes
expert in the Department of Molecular Medicine at Cornell University. The
team has submitted proposals to the National Institutes of Health and the
American Diabetes Association to further validate the technology with
additional data and to extend the work to identify and characterize other
microscopic cellular structures.