Research
Researchers from the University of Utah (Salt Lake City, Utah) and the Oregon National Primate Research Center (Beaverton, Oregon) used gas chromatography–mass spectrometry-based metabolomics to analyze blood from mothers and offspring of animals fed a
high-fat diet. They found that a high-fat diet during pregnancy results in offspring with fatty livers and causes changes
in the small molecules that govern metabolism, including fatty acids and amino acids most likely to affect energy use and
fat storage. The study was led by a research group at Baylor College of Medicine (Houston, Texas). In their study, they compared three groups: mothers fed a 13% fat-control diet and their offspring, mothers fed a 35% fat
diet and their offspring, and mothers who were obese but on a control diet during pregnancy and their offspring. The metabolomic
footprint included more than 1300 chromatographic features.
• Researchers from Imperial College London and Eindhoven University of Technology (The Netherlands) have developed a sensor using fluorescence proteins that act as a molecular switch by changing color when they bind to zinc,
which can reveal the amount of zinc in cells. The development is significant because it could tell scientists more about a
number of diseases, including type-2 diabetes. The new sensor, called a fluorescence resonance energy transfer (FRET)-based
sensor, is made up of two color variants of a green fluorescent protein from jellyfish. The researchers altered the first
variant to give off light at a certain wavelength, and altered the second variant to collect that light. When the proteins
attached to zinc ions, they became pushed apart and the transfer of light between them became weaker. The researchers used
a fluorescence microscope to detect the wavelengths of light emitted by the proteins. This revealed colored patches where
the proteins detected zinc in the cell. They then used this new sensor to look for zinc in pancreatic cells, where insulin
is packaged around zinc ions. Previous research had suggested that in people with type 2 diabetes, the gene that controls
the packaging process is often defective, affecting the way insulin is stored. The researchers found a high concentration
of zinc ions inside certain parts of the cell where insulin is found. It is hoped that this new sensor might help scientists
look more closely at this to determine exactly how zinc is involved in diabetes.
• Scientists at UT Southwestern Medical Center (Dallas, Texas) are the first in the U.S. to use magnetic resonance spectroscopy (MRS) to measure the amount of pancreatic fat in humans.
Although scientists worldwide already use MRS to investigate a number of other diseases, the team at UT Southwestern has successfully
used the noninvasive technique to measure pancreatic fat. MRS uses no radiation and is completely noninvasive. The test generally
takes 20 to 30 minutes. While magnetic resonance imaging (MRI) can tell clinicians where a tumor is located, MRS can actually
tell those physicians if the tumor is malignant by providing biochemical information about specific tissues in the body rather
than simply detecting the existence of those tissues. The researchers believe that measuring pancreatic fat content could
one day serve as an effective diagnostic tool to identify those at high risk for diabetes and monitor interventions designed
to prevent the disease. • Scientists at Brown University (Providence, Rhode Island) have discovered that the moon contains distinct signatures of water. Findings from the Moon Mineralogy Mapper (M3), a NASA
instrument aboard the Indian spacecraft Chandrayaan-1, reveal the presence of water molecules and hydroxyl, a molecule consisting
of one oxygen atom and one hydrogen atom. The M3 team found water molecules and hydroxyl at diverse areas of the sunlit region
of the moon's surface, but the water signature appeared stronger at the moon's higher latitudes.
While orbiting the moon, M3's spectrometer measured light reflecting off the moon's surface at infrared wavelengths, splitting
the spectral colors of the lunar surface into small enough bits to reveal a new level of detail in surface composition. Upon
analysis of the data from the instrument, the M3 team found that the wavelengths of light being absorbed were consistent with
the absorption patterns for water molecules and hydroxyl.
Initially, the researchers believed that there must have been something wrong with the instrument on Chandrayaan-1, because
they knew that the moon had no water on its surface. M3's discovery was then confirmed by reviewing data from two other NASA
spacecrafts — the Visual and Infrared Mapping Spectrometer (VIMS) on the Cassini spacecraft that flew by the moon 10 years
ago on its way to Saturn, and the High-Resolution Infrared Imaging Spectrometer on the EPOXI spacecraft, which is headed for
a comet but passed by the moon in June. Both instruments confirmed the presence of the water-hydroxyl signature on the moon's
surface.
