Jet Lag of the Liver Adjusting meal times may help travelers avoid the stomach upset sometimes associated with jet lag, suggests new research on circadian rhythms. The bane of globe-trotters, jet lag occurs when a person's sleep schedule is at odds with local time. Sunlight helps adjust the body clock, and now there may be another way to help get the system acquainted to a new time zone. In today's Science, researchers report that the timing of meals can reset a biological clock in the liver, which might help it rev up enzyme production at the right time for digestion. The finding may one day help doctors optimize the timing of treatments for liver diseases. The body is full of clocks. These circadian rhythms--such as waxing and waning levels of the expression of certain genes--tick in organs from the lungs to the liver. Normally, these rhythms are in step with a master clock in the brain that is controlled by the cycle of daylight and darkness. However, it's not known if the brain synchronizes the other clocks directly (through the timed release of hormones, for example) or if external stimuli play a role in setting them. --GREG MILLER Copyright © 2001 by the American Association for the Advancement of Science.

Keyword:
Link ID: 167 - Posted: 10.20.2001

Protein May Tie Obesity to Diabetes Nathan Seppa The high incidence of obesity among people with type II diabetes suggests a connection between the two conditions. Scientists have sought a link by studying insulin resistance, the trademark symptom of type II, or adult-onset, diabetes. But they still don't know why cells in people with insulin resistance ignore insulin's signals to process blood glucose for use by muscles and other tissues. Researchers working with mice have now identified a hormone, called resistin, that is secreted by fat cells and appears to play a direct role in type II diabetes. Healthy mice given doses of extra resistin for 2 days develop insulin resistance, researchers at the University of Pennsylvania in Philadelphia report in the Jan. 18 Nature. From Science News, Vol. 159, No. 3, Jan. 20, 2001, p. 36. Copyright © 2001 Science Service. All rights reserved.

Keyword: Obesity
Link ID: 166 - Posted: 10.20.2001

How Your Brain Knows Your Face Breakthrough tests show self-recognition is an ability of the right lobe Keay Davidson, Chronicle Science Writer Thursday, January 18, 2001 Somewhere inside the brain, obscured by thickets of neural circuitry and throbbing blood vessels, is the "self" -- that murky whatever-it-is that makes you feel like a conscious, self-aware human being. For centuries, scholars have debated what the self is. Is it a nonmaterial entity -- a little ghost, as it were -- that can't possibly be explained in terms of biology, physics or chemistry? Or is it a purely material thing, one that generates a person's sense of selfhood as a cathode-ray tube generates TV images? Now -- with a little help from Marilyn Monroe, Princess Diana, Bill Clinton and Albert Einstein -- scientists are beginning to analyze the neurological machinery that enables one to look in a mirror and say: "That's me." ©2001 San Francisco Chronicle Page A2

Keyword: Attention
Link ID: 163 - Posted: 10.20.2001

Link found between diabetes and obesity DAVID ADAM More than 80% of diabetics are also obese, but a link between the two conditions has proved difficult to find. Now, in a series of experiments with mice, Mitchell Lazar and his colleagues at the University of Pennsylvania School of Medicine, Philadelphia, show that a protein called resistin, which is produced by fat cells, plays a role in diabetes. The team suggests that, if the action of human resistin is similar to mouse resistin, new drugs targeting the hormone could bring relief from diabetes, which can lead to heart disease, stroke, kidney failure and nerve damage. Diabetic mice with both diet-induced and genetic obesity have higher resistin levels. The researchers also show that an antidiabetic drug reduces resistin, and that administering an antiresistin antibody improves blood-sugar control and insulin action in mice on a high-fat diet. .... 1.Steppan, C. M. et al. The hormone resistin links obesity to diabetes. Nature 409, 307–312 (2001). © Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Obesity
Link ID: 162 - Posted: 06.24.2010

Boom and bust DAVID ADAM Gravel in a man's throat means hair on his chest, or so women believe. Ladies rate unseen men with deeper voices as more attractive, older, heavier and hairier, new research reveals. But arranging a blind date over the telephone could be surprising - baritone blokes are no more likely to be muscle-bound than are their soprano-sounding friends. Sarah Collins, a behavioural biologist at the Institute of Evolutionary and Ecological Sciences in Leiden, the Netherlands, recorded Dutch men's voices and played them to Dutch women, who then tried to predict what the speakers looked like. 1.Collins, S. Men's voices and women's choices. Animal Behaviour 60, 773–780 (2001). © Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Sexual Behavior
Link ID: 161 - Posted: 06.24.2010

New Haven, Conn. -- Continued use of anti-depressants leads to new cell growth in an area of the brain known to suffer cell death and atrophy as a result of depression and stress, a study by Yale researchers shows. Depression affects an estimated 12 percent to 17 percent of the population at some point during their lifetime. Anti-depressants are commonly prescribed for depression and other affective disorders, but the drugs' therapeutic effects on the molecular and cellular level are not clearly understood.

Keyword: Depression
Link ID: 160 - Posted: 10.20.2001

Birds Follow the Sun Following the sun imperfectly turns out to be the perfect solution for navigation if you're a bird in the Arctic, researchers have found. By using the sun to orient themselves, tundra-breeding shorebirds end up approximating the "great circle routes" used by airplanes and ships--routes that minimize the distance between two points on the surface of a sphere. Birds can travel thousands of kilometers and arrive at breeding and wintering grounds with pinpoint precision. Fascinated, biologists have investigated this ability for decades. They've learned that birds take their bearings from such things as stars, the sun, landmarks, and Earth's magnetic field. But existing ideas didn't explain why some birds in the Arctic fly east before heading south. So ornithologist Thomas Alerstam of Lund University in Sweden and colleagues used the radar on a Canadian icebreaker in the Northwest Passage to measure the direction of migrating birds flying past. .... --JAY WITHGOTT Copyright © 2001 by the American Association for the Advancement of Science.

Keyword: Miscellaneous
Link ID: 159 - Posted: 10.20.2001

Academic impacts of vegetarian childhoods By Janet Raloff Teens are always looking for creative excuses for late homework, low test scores, and waning attention in class. Any who stumbled onto a copy of the September AMERICAN JOURNAL OF CLINICAL NUTRITION may have uncovered the basis for a particularly novel rationalization: "My parents made me a vegetarian." Plants do not make vitamin B-12, also known as cobalamin. Diets that eschew all animal products can therefore lead to B-12 deficiencies. Because the vitamin plays a key role in some brain functions, toddlers raised from weaning on strictly plant-based foods can experience delays in the acquisition of certain motor skills. In a few instances, infants in strictly vegetarian families have shown severe anemia, dramatic growth retardation, irritability-and in at least one case, went into a coma. References: Louwman, M.W.J., et al. 2000. Signs of impaired cognitive function in adolescents with marginal B-12 status. American Journal of Clinical Nutrition 72(September):762. Watanabe, F., et al. 1998. Effects of microwave heating on the loss of vitamin B12 in foods. Journal of Agricultural and Food Chemistry 46(January):206. Copyright © 2001 Science Service. All rights reserved.

Keyword: Development of the Brain
Link ID: 158 - Posted: 10.20.2001

MIT researchers find individual brain cells 'tuned' to entire categories of information Monkeys learn to see differences between cats and dogs JANUARY 11, 2001 Contact information CAMBRIDGE, Mass. -- Researchers at the Massachusetts Institute of Technology found that individual neurons in monkeys' brains can become tuned to the concept of "cat" and others to the concept of "dog. The study suggests that people, too, have individual neurons sensitive to categories of our most familiar things. This is the first time, the MIT researchers report in the Jan. 12 issue of Science, that individual brain cells have been linked with one of the brain's most important cognitive functions: the ability to instantly categorize what we see.

Keyword: Neurotoxins
Link ID: 157 - Posted: 10.20.2001

Herring aid DAVID ADAM Fish living in the murky rivers of West Africa have evolved their own hearing-aids. A tiny gas-filled bubble inside the ear of the mormyrid electric fish vibrates as mating calls or alarm signals pass through the water. The fish hears the sounds because the bubble brushes against sensory hairs. Deflating the bubble renders the fish deaf, Lindsay Fletcher and John Crawford at the University of Pennsylvania, Philadelphia, now report. Biologists have suspected that the bubbles are crucial to mormyrid hearing since the 1930s, but advances in surgery have only now allowed the idea to be tested. 1.Fletcher, L. B. & Crawford, J. D. Acoustic detection by sound-producing fishes (Mormyridae): the role of gas-filled tympanic bladders. Journal of Experimental Biology 204, 175–183 (2001). 2.Yan, H. Y. & Curtsinger, W. S. The otic gasbladder as an ancillary auditory structure in a mormyrid fish. Journal of Comparative Physiology A 186, 595–602 (2000). .© Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2000 Reg. No. 785998 England.

Keyword: Animal Communication
Link ID: 154 - Posted: 06.24.2010

Eavesdropping on Secrets of Elephant Society By ANDREW C. REVKIN Katharine Payne is one of science's consummate listeners. Starting first with whales, and then moving ashore to study elephants 16 years ago, she has built a career divining the significance of sounds emitted by two of the world's largest, and most mysterious, mammals. Andrea Turkalo is one of science's consummate watchers. A former biology teacher in the South Bronx, she has spent a decade perched on a rough- hewn platform in an opening in the rain forests of the Central African Republic, intently observing the interactions of hundreds of forest elephants that briefly leave the dense jungle to partake of the minerals and water in mudholes there. It is estimated that perhaps half of Africa's remaining elephants are of the forest-dwelling subspecies, and thus live largely out of sight and are barely understood. Copyright 2001 The New York Times Company

Keyword: Animal Communication
Link ID: 153 - Posted: 10.20.2001

GenSAT, others to house rapidly expanding genetic data
By Jean McCann
Researchers maintain and constantly add to numerous gene databases as science progresses in its effort to map the human body. The recent announcement of a major new database initiative, however, may, as one researcher noted, "change the culture of neuroscience." Thanks to financial support from the National Institute of Neurological Disorders and Stroke, explained Gabrielle LeBlanc of NINDS during the recent Society for Neuroscience annual meeting in New Orleans, neuroscientists will be able to access images of gene expression from the brain in one database instead of gathering data from many disparate sources. The GenSAT project, named after NASA's LANDSAT, which shows population densities or other features as captured by satellites, will show regions of density of highly activated gene expression as seen through fluoroscopic microscopes. "We expect this to be a tremendous resource for the community, because now they won't have to do this piecemeal on a lab-by-lab basis, but everyone will have a common pool of knowledge that they can look at and analyze how genes are expressed," said LeBlanc, who demonstrated a prototype of the database at the neuroscience meeting. She also described how the database could interact with microarray and mutational analysis for the better understanding of gene function. Jean McCann (jmmednews@aol.com) is a science writer in Cleveland Heights, Ohio. The Scientist 15[1]:8, Jan. 8, 2001 © Copyright 2001, The Scientist, Inc. All rights reserved.

Keyword: Genes & Behavior
Link ID: 151 - Posted: 10.20.2001

Music Through the Years and Ears Scientists say a taste for melody crosses lines of time and species David L. Chandler, Boston Globe Friday, January 5, 2001 It has long been a cliche that music is universal, but now science is proving just how deeply true the old saying really is. While scientists can't do much better than the rest of us in defining exactly what music is -- although they know it when they hear it -- they have shown that human appreciation of music is remarkably ancient, begins astonishingly early in life, and to a surprising extent may be shared by whales, birds and even rats. ©2001 San Francisco Chronicle Page A8

Keyword: Hearing
Link ID: 148 - Posted: 10.20.2001

DURHAM, N.C. - In experiments using cell cultures and gene-altered mice, researchers have found that switching on just two genes can induce considerable regeneration of damaged nerve fibers in the spinal cord. Their finding suggests that genetic therapy or drugs that activate perhaps only a handful of genes might be enough to induce regeneration of spinal cords in humans with spinal cord injury or other central nervous system damage. In addition, the scientists said their in vitro method of testing the effects of such treatments on cultured nerve cells should speed research on such therapies.

Keyword: Regeneration
Link ID: 147 - Posted: 10.20.2001

Brain Damage In Autism: Not What Scientists Once Thought Deepening the mystery of autism's origins, a Johns Hopkins Children's Center study has failed to link the typical autistic child's fixation on spinning objects and constant whirling around to long-suspected damage to the brain's control center for movement, balance and equilibrium. Reporting in the December 2000 issue of the Journal of Autism and Developmental Disorders, the Hopkins team said test results of parts of the cerebellum in 13 autistic children were the same as in normal children without autism.

Keyword: Autism
Link ID: 146 - Posted: 10.20.2001

Combination of Two Widely Used Pesticides Linked to Parkinson's Disease Scientists have shown that the combination of two widely used agricultural pesticides-but neither one alone-creates in mice the exact pattern of brain damage that doctors see in patients with Parkinson's disease. The research offers the most compelling evidence yet that everyday environmental factors may play a role in the development of the disease. The latest findings of the team led by Deborah Cory-Slechta, Ph.D., professor of environmental medicine and dean for research at the University of Rochester School of Medicine and Dentistry, appear in the Dec. 15 issue of the Journal of Neuroscience. The scientists caution that more studies are necessary to explain the link, since it's probable that many factors contribute to a complex disease like Parkinson's, and they say it's unlikely that the pesticides on their own actually cause the disease. ©Copyright University of Rochester Medical Center, 1999-2000.

Keyword: Parkinsons
Link ID: 145 - Posted: 10.20.2001

A Way to Shrink Brain Tumors Patients with a particularly aggressive type of brain cancer typically don't have many treatment options. But a new technique tested in mice and rats might provide a tool to combat the lethal tumors, known as glioblastomas. The strategy is to deliver growth-suppressing drugs directly and sustainedly to the tumor. If it works in humans, the technique could prolong the lives of some brain cancer patients, and it might be applicable to other types of cancer as well. Glioblastomal tumors make up about one-quarter of the cases of brain cancer, and most patients survive for no more than 18 months past diagnosis. But the cancer's fast growth makes it a good candidate for tumor-shrinking compounds called angiogenesis inhibitors. These proteins, such as endostatin, inhibit the growth of blood vessels that the tumors need to grow and spread (ScienceNOW, 23 January 1997). Getting angiogenesis inhibitors into brain tumors and keeping them there, however, has been a problem. .... --JOHN S. MacNEIL Copyright © 2001 by the American Association for the Advancement of Science.

Keyword: Glia
Link ID: 144 - Posted: 10.20.2001

Schizophrenia: volume matters XAVIER BOSCH Some early-stage schizophrenics may have a brain region that is smaller than average. Tonmoy Sharma of King's College London, UK and colleagues used magnetic resonance imaging to reveal that the volume of the thalamus differed by about 5% between 38 first-episode schizophrenic patients and 29 healthy subjects. Imaging studies and postmortem evidence has suggested before that this might be the case but Sharma's group provides the first concrete evidence for a volume discrepancy in untreated, nascent schitzophrenia in their American Journal of Psychiatry1 report. 1.Ettinger U, Chitnis XA, Kumari V, et al. Magnetic Resonance Imaging of the Thalamus in First-Episode Psychosis. American Journal of Psychiatry 158, (2001). .© Macmillan Magazines Ltd 2000 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2000 Reg. No. 785998 England.

Keyword: Schizophrenia
Link ID: 143 - Posted: 10.20.2001

IMPRINTED GENE FOUND ON HUMAN CHROMOSOME 19; MOUSE VERSION INVOLVED IN NURTURING BEHAVIOR DURHAM, N.C. - Duke University Medical Center researchers report that an unusual gene-control mechanism called "imprinting" is at work on human chromosome 19. For imprinted genes, the gene copy that is turned on depends only on whether it came from the mother or father, rather than on the classic laws of Mendelian genetics, where genes are either dominant or recessive. In the Jan. 1, 2001, issue of Genomics, the researchers report that a particular gene called PEG3, or paternally expressed gene 3, is imprinted in humans, just as it is in mice. Mouse studies have shown that only the copy of PEG3 that is inherited from the father is functional, and the Duke researchers now have confirmed that is true in humans as well.

Keyword: Genes & Behavior
Link ID: 142 - Posted: 10.20.2001

By ERICA GOODE Here is the problem, as Dr. Linda Bartoshuk sees it: Say that two men, call them Richard and John, are both suffering from depression, and a researcher wants to find out if a particular medication will offer them relief. Asked to rate the intensity of his depression on a scale of 1 to 10, Richard selects a 6. John, given the same rating scale, also picks a 6. But does he feel the same degree of depression as John? Copyright 2001 The New York Times Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 141 - Posted: 10.20.2001