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SCIENCE NOTES
NEWS IN GENETICS, ASTRONOMY

Engineering opium poppies to produce different drugs

Scientists have created genetically engineered opium poppies that can barely produce the morphine, codeine and other potent drugs that make the plants so highly prized on the black market. Instead, the gene-altered flowers build up caches of other chemicals that can be used to make new medications.

Australian researcher Philip Larkin and his team reported in the online issue of Nature Biotechnology that they knew poppies make morphine from the simple amino acid tyrosine in a series of 18 steps. At each step, a different enzyme turns one chemical compound into another.

Using a recently developed genetic technique that allows scientists to block the activity of individual enzymes, Larkin's group dammed the synthetic pathway midstream, causing a buildup of the chemical precursors of morphine. One of the precursors that accumulated at especially high levels, called (S)-reticuline, had already shown promise for a number of conditions ranging from baldness to malaria.

-- Washington Post

Lower levels of DHEA may be tied to aging

Giving elderly people supplements of a hormone that tends to decrease as people age may help prevent weight gain and the increased risk of diabetes that often accompanies aging, according to a preliminary study.

The hormone dehydroepiandrosterone (DHEA) is produced by the adrenal glands. Levels peak at about age 20 and then gradually decline with age. By the time most people are about 70, their DHEA levels have fallen to only about 20 percent of their peak levels. Scientists have speculated that dropped DHEA levels may help explain many of the effects of aging.

Dennis T. Villareal and John O. Holloszy of Washington University School of Medicine in St. Louis gave 28 men and 28 women ages 65 to 78 either 50 milligrams of DHEA each day or a placebo.

After six months, those getting DHEA had 7.4 to 10.2 percent less fat in their abdomens than those getting the placebo, the researchers found. And those getting the hormone appeared to control their blood sugar levels better than those who got the placebo, indicating they may be less likely to develop diabetes. No adverse effects occurred, the researchers wrote in the Journal of the American Medical Association.

-- Washington Post

Young planet could be cause of star gap

Using the sensitive infrared spectrograph on NASA's Spitzer Space Telescope, University of Rochester astronomers earlier this year observed a gap that appears like a moat surrounding CoKu Tau 4, a young star about 1 million years old.

Astronomer Dan Watson said in a telephone interview that the only explanation that appeared to make sense was that a planet even younger than the star was plowing a trough in the disc and had taken up all the material in the gap.

"All young stars have discs around them, and they tend to be dusty and dense," Watson said. Planets eventually form from the material in dust discs, but not -- at least according to prevailing theories -- so quickly.

Last week, a second team of University of Rochester astronomers reported that by analyzing Watson's data, they were able to demonstrate that a Saturn-sized planet or larger could have dug the trough surrounding CoKu Tau 4.

-- Washington Post

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