TIP SHEET: RECENT SCIENCE ADVANCES FROM HOPKINS MEDICINE
Listed below are story ideas from the Johns Hopkins Medical Institutions. To pursue any of these stories contact Joanna Downer at (410) 614-5105 or [email protected]
JOHNS HOPKINS SCIENTISTS FIND BRAIN'S NOSE PLUG
Scientists from The Johns Hopkins University School of Medicine and elsewhere have found the brain's "nose plug" - the switch in the brain that lets us stop smelling something, even though the odor is still there.
Two papers published in a recent issue of Science show that a protein called CNGA4 helps plug the "nose" of odor receptor cells -- neurons whose job is to detect smells and send that information to the brain as an electrical signal. The "nose" is really a channel in the neurons' membrane that opens when an odor is presented and closes as the neuron becomes desensitized to that smell.
By measuring the signals from these odor receptor cells in genetically engineered mice, one research team showed that mice lacking CNGA4 could sense odors but could not adapt to them. Other scientists studied the molecule's behavior in laboratory-grown cells and reported that CNGA4 speeds up the "nose's" closing. Without CNGA4, the closing took 100 times longer.
Full Release: http://www.hopkinsmedicine.org/press/2001/DECEMBER/011207.htm
Primary Authors:Randall Reed, Ph.D., a Howard Hughes Medical Institute (HHMI) investigator and a molecular biologist and neuroscientist at Hopkins' Institute for Basic Biomedical Sciences
Jonathan Bradley, Ph.D., a postdoctoral fellow in neuroscience in HHMI at Johns Hopkins
EAT YOUR VEGGIES: INDIRECT ANTI-OXIDANTS PROVIDE LONG-TERM PROTECTION
A cancer-preventing compound in broccoli, first isolated a decade ago at Hopkins, may protect against a much broader spectrum of diseases. A new study shows that the compound, sulforaphane, helps cells defend themselves for two or three days against highly reactive and toxic molecules called oxidants.
Unlike standard anti-oxidants that use the molecular equivalent of hand-to-hand combat, broccoli's compound is a covert operative that works indirectly. Oxidants are like molecular hit men, damaging DNA and killing cells, eventually leading to cancer, retinal degeneration, atherosclerosis and other conditions unless they are neutralized.
According to the investigators, it turns out that sulforaphane's anti-cancer properties and its indirect anti-oxidant effects are both due to its ability to make cells create a diverse group of enzymes, called "phase 2" enzymes, that protect against cancer by blocking select chemicals from becoming carcinogens. Not previously considered oxidant fighters, the enzymes have the ability to detoxify oxidants, which increases their value in disease prevention, say the scientists.
The scientists studied sulforaphane's effects on a variety of cell types and oxidants in laboratory experiments, they report in a recent issue of the Proceedings of the National Academy of Sciences. Sulforaphane is particularly abundant in three-day-old broccoli sprouts.
Full Release: http://www.hopkinsmedicine.org/press/2001/DECEMBER/011218A.htm
Primary Author:
Paul Talalay, M.D., J.J. Abel Distinguished Service Professor of Pharmacology at the Johns Hopkins School of Medicine
NOTE: Talalay, his colleagues and Johns Hopkins hold patents related to the sulforaphane and broccoli sprout research. In 1998, Talalay, in cooperation with Johns Hopkins University, formed Brassica Protection Products LLC, a Baltimore firm that commissions the growth, harvest and marketing of broccoli sprouts with tested and guaranteed levels of sulforaphane. The terms of this arrangement are being managed by the University in accordance with its conflict of interest policies.
TETHER FOR WATER CHANNELS FOUND: MAY IMPACT RESEARCH ON BRAIN SWELLING
A team of scientists from Johns Hopkins and elsewhere has discovered that a protein involved in muscle-wasting diseases plays a role in moving water in and out of brain cells. The finding opens new avenues of inquiry for treating potentially lethal brain swelling from injury and stroke.
Brain swelling occurs when water molecules pass through a microscopic "channel" into certain brain cells. In a recent issue of the Proceedings of the National Academy of Sciences, the scientists report that the alpha-Syntrophin protein keeps these prevalent water channels where they belong.
By tethering the water channel protein, Aquaporin-4 (AQP4), to the tips of certain brain cells, Syntrophin keeps the openings for water right next to blood vessels. Without Syntrophin, the water channels are everywhere on the brain cells except where they are supposed to be, the scientists found. They are still evaluating the effect this shift has on mice.
In addition to influencing research on brain swelling, the finding also creates a new view of the invisible barrier between the blood and the brain, one that involves a separate barrier for water, the scientists suggest.
Full Release: http://www.hopkinsmedicine.org/press/2001/NOVEMBER/011119A.htm
Primary Author:
Peter Agre, M.D., professor of biological chemistry in the Johns Hopkins School of Medicine's Institute for Basic Biomedical Sciences
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