Note : Just for online reading, not for redistribution * Icecap Seen on Mars' North Pole SAN FRANCISCO (AP, 7/12/98) ? Some scientists think Mars' north pole looks like a hockey puck. Others liken it to an icy meringue. Its frosty surface slopes as gently as a beginner's ski run in some places, but it's also riddled with gorges and cliffs; one trough plunges deeper than the Grand Canyon. On one thing planetary scientists analyzing the first close-up views of the top of Mars can agree: It looks like nothing they've seen before. ``Similar features do not occur on any glacial or polar terrain on Earth,'' said Maria Zuber of the Massachusetts Institute of Technology. Researchers discussed the new three-dimensional images supplied by the Mars Global Surveyor spacecraft on Sunday at the American Geophysical Union meeting here. More details on the Martian pole will be published Friday in the journal Science. It's the latest discovery in what is now a two-year mission by the spacecraft to orbit the Red Planet and capture images of its surface with a variety of instruments, providing detail that is not available even for some locations on Earth. The north pole images have left many researchers intrigued, but perhaps a little disappointed. It is made of water ice, which could be a good omen for finding at least traces of ancient life somewhere on the planet. But while the northern ice cap covers an area 50 percent greater than Texas, researchers had expected it to be bigger. Even with Mars' very cold climate, it is only half the size of the ice cap covering Greenland and only 4 percent of the Antarctica's combined ice sheets. The amount of water trapped in the ice cap is not sufficient to have carved the deep gullies that scar the surface of the planet, and is about 10 times less than the minimum volume that researchers believe would have been necessary to fill an ancient ocean. It rests in a deep basin at the top of the planet that might have been created by an asteroid impact similar to craters on the Moon. The ice cap measures 750 miles and is 1.8 miles thick. ``It looks like a hockey puck in a shallow depression,'' said David Smith of NASA-Goddard Space Flight Center in Greenbelt, Md. Mars Global Surveyor is gradually descending into the Martian atmosphere using its own aerodynamic drag to slow down. Since last summer it has made over 180 looping orbits around the planet's poles, passing as close as 80 miles above the ice cap. Carbon dioxide clouds over the ice cap are likely to be composed of carbon condensed out of the frigid atmosphere during the winter in the northern hemisphere, researchers said. The new images raise more questions about past conditions on Mars than they answer. For example, how did the ice cap form? Because the ice cap rests in a basin, it is likely that liquid water on the planet's surface flowed north from the equator to the pole. If true, it would mean that scientists must reconsider theories of the hydrologic cycle on Mars. Features apparent in other images of Mars' northern hemisphere show evidence of ancient springs. These springs may have supplied the additional water required to carve surface features. ``The springs apparently were fed by groundwater,'' said Michael Carr of the U.S. Geological Survey. ``The amount of ice in the cap cannot possibly explain the features that we see. I think the water is there now.'' NASA plans to launch its next unmanned satellite to study the Martian climate on Thursday. In January, the space agency plans to launch another spacecraft to study the south pole of Mars. * Jupiter's Fault Is Like San Andreas SAN FRANCISCO (AP, 7/12/98) ? New pictures from the Galileo spacecraft orbiting Jupiter show that a fault line on one of the giant planet's moons is similar to the infamous San Andreas fault. The fault on the moon Europa extends for more than 500 miles and curves down and across the bottom of the moon. The images show that about 30 miles of displacement, or movement, has taken place along the fault. Like the San Andreas, it is a strike-slip fault. Rather than moving up and down, the sides of the fault move horizontally past each other like opposing lanes of traffic. Unlike the California fault, scientists believe the fault on Europa is not active. But that doesn't make it any less interesting ? or satisfying ? to study, they said. ``I think it is a beautiful structure,'' said Randy Tufts of the University of Arizona, one of the scientists examining the images of the fault, which has been named Astypalacea Linea. ``Comparisons between it and faults on Earth may generate ideas we can use in studying movements here on our planet,'' Tufts said. ``On Europa, we can see this structure very clearly. It's not covered by trees like the San Andreas.'' Images of the fault were among several discoveries about Jupiter discussed Monday at a meeting of the American Geophysical Union. Galileo and Earth-_base_d telescopes have been examining enormous storms in Jupiter's swirling atmosphere. They persist for decades, or even centuries; the Giant Red Spot has been raging for at least 300 years. In a study released Monday, scientists said two of three large storms in the planet's southern hemisphere known as the White Ovals merged in February. The White Ovals have been active since at least 1938. But it is the fault line on Europa that is attracting most of the attention from the Galileo mission at the moment. Europa is a very different world than Earth, and scientists say different forces probably controlled the fault despite its outward resemblance to the San Andreas. On Earth, quakes are triggered by grinding movements and pressures exerted by the planet's rocky crust. But Europa is not solid. It is encased in a _layer_ of ice, but beneath it probably is a huge body of salt water. The presence of water and residual heat from the moon's formation has raised scientists' hopes that Europa might have harbored early life. ``We see a cold, hard, brittle outer _layer_, but a lot of activity underneath,'' said James Head, a geologist at Brown University. ``Does it represent an ocean under there, or warm ice moving around?'' Tidal forces generated by Jupiter's powerful gravity field tugging on Europa's icy shell probably trigger motion along the fault line. Material from beneath the ice cap has welled up into the breach. In many places, tidal forces apparently opened the fault, caused it to slip in one direction and closed it up again, Tufts said. A secondary force might be a slightly unsynchronous orbit that would create different stresses on the moon's brittle ice shell, he said. Galileo was launched in 1989. It arrived at Jupiter on Dec. 7, 1995 and aimed its sensors on the giant planet for two years. It will examine Jupiter's primary moons until 2000 or longer. NASA plans to dispatch another spacecraft to Jupiter in 2003. * Houston, We Have a Space Station HOUSTON (Reuters, 7/12/98) - The International Space Station became a reality on Sunday as its first two components were brought together in orbit by the crew of the US space shuttle Endeavour. The Russian-built Zarya power module and the US-built Unity module were the first of more than 100 space station components scheduled to be added over the next five years in one of the most ambitious and expensive engineering feats ever undertaken. We have capture of Zarya, shuttle commander Robert Cabana reported to Mission Control as the newly joined complex passed some 200 miles above the South Pacific. We copy, called back spacecraft communicator Chris Hadfield from Houston. Congratulations to the crew of the good ship Endeavour. As Endeavour's robot arm held Zarya in place a few inches above Unity, already secured to the shuttle's own docking bay, Cabana nudged Endeavour toward Zarya, causing the modules to gently bump together and locking their docking mechanisms in place. Sixteen nations are involved in the $60 billion space station project, which will require more than 40 manned missions and hundreds of hours of space walks during the construction phase. Endeavour's six-member crew will enter the station on Thursday, but the first crew to live there will go up in 2000 after a Russian command module with living quarters is in place. Endeavour, carrying Unity in its payload bay, had chased the unmanned space station component for two days. Mission specialist Nancy Currie used the 50-foot robot arm to position Zarya, which was sent aloft last month, within a few inches of Unity, already upright and rising three-stories above the shuttle's docking bay. Zarya will supply power and navigational control during the early stages of space station construction. Unity is a honeycomb of hatches and docking ports that will _link_ a half-dozen science, service and living modules. It also has a docking port for future shuttle missions. The start of the Zarya rendezvous was delayed when Cabana fired Endeavour's jets early on Sunday to move it away from the path of space debris left from the Nov. 6 launch of a Delta II rocket from Vandenberg Air Force _base_ in California. Endeavour would have missed the debris by 1.6 miles (2.5 km), but Flight Director John Shannon in Houston decided to put the shuttle well out of harm's way, NASA spokesman James Hartsfield said. The Endeavour crew trained for two years for this mission, delayed by a year as the cash-strapped Russian space programme struggled to complete a third station component, a command module with living space for rotating crews of three. When that piece is added, the space station will become functional. * Radiation Belts Pose Risks in Space SAN FRANCISCO (AP, 7/12/98) ? The radiation belts surrounding Earth can become extremely powerful in a matter of seconds, posing far greater risks to spacewalking astronauts and communication satellites than previously believed, scientists said Monday. ``We had thought the radiation belts were a slow, lumbering feature of Earth, but in fact they can change on a knife's edge,'' said space physicist Daniel Baker of the University of Colorado. The new observation, discussed at the American Geophysical Union meeting here, caught scientists by surprise. Originally detected 40 years ago, the doughnut- shaped structures known as the Van Allen Belts extending more than 20,000 miles around the planet were thought to be very stable, waxing and waning over a period of months. New observations by an array of satellites show changes in the planet's own magnetic field can accelerate electrons in the belts to nearly the speed of light, transforming them into what some researchers describe as ``killer electrons.'' The mechanism by which the acceleration occurs is unclear, but its effects are more obvious. Under such intense conditions, the charged particles can pierce a sheet of aluminum a half-inch thick. That could result in a catastrophic accumulation of charged particles in the sensitive electronics of hundreds of orbiting satellite, and perhaps endanger astronauts. Shielding people and hardware in space is expensive and heavy, and the discovery may compel space engineers to design orbiting systems differently. ``Many of the satellites up there now, and future spacecraft like the space station, have the potential to be severely impaired by light-speed electrons,'' Baker said. Consumers already have experienced a taste of what can happen when the Van Allen Belts, in the words of one researcher, ``get whipping along.'' In early May, sensors on at least 10 science satellites started picking up indications that electrons were accelerating into an intense flux. On May 19, a heavily used telecommunications satellite, Galaxy 4, failed suddenly and 45 million customers lost pager service. Scientists think the electron flow contributed to the outage. Such fluxes also may have contributed to the failure of a Canadian telecommunications satellite, Anik E1, in 1996. The risk to NASA's manned space program is less certain. Satellites orbit 22,000 miles above the planet in the midst of the most energetic fields of the Van Allen Belts. The space shuttle and the space station orbit within about 250 miles of Earth. Scientists said that during intense periods the charged particles pulse down into the atmosphere. Researchers said they cannot yet precisely forecast when the belts of highly charged electrons will peak in intensity, but they are advising NASA when conditions appear to be changing so the agency can decide whether to delay space missions. NASA plans more than two dozen spacewalks a year during the assembly of the international space station. The first spacewalk was scheduled for Monday evening. The health risk to astronauts ? as well as the space shuttle's electronics ? is unclear. ``If one of these events occurs during the space station assembly, do you have the astronauts hurry up and risk ripping a glove?'' said space physicist Terry Onsager of the National Oceanic and Atmospheric Administration. ``Or do you let the mission go as planned?'' Scientists expect the Van Allen belts to become highly dynamic beginning in late 2000 during the Solar Max. That's the peak of a cyclical period of violent storms on the sun that fill the solar system with charged particles. ``We can expect to see dramatic events during Solar Max,'' Onsager said. * Space Walkers Finish Connections SPACE CENTER, Houston (AP, 7/12/98) ? Two spacewalking astronauts hooked up all 40 electrical connections between the first two pieces of the international space station on Monday. To NASA's surprise, the critical wiring job took less time than expected. Jerry Ross, NASA's most experienced spacewalker, snapped the connectors together as James Newman handed him the attached cables. They were mightily impressed with the seven-story station towering above them. ``This is sure a beautiful piece of hardware,'' Newman said. Ross worked n_onstop_ from the end of Endeavour's 50-foot robot arm, starting at the bottom with the American-made Unity module. He attached jumper cables there before being hoisted more than 40 feet to the Russian-built Zarya stacked on top. ``Jerry, How's the view?'' Newman called out from below. ``Fantastic if I had time to look,'' Ross replied. Ross and Newman completed the electrical connections four hours into their planned 6 1/2 -hour spacewalk, the first of three scheduled for this week. The next step was for flight controllers to turn on the power inside the fledgling station; electricity had been turned off to the cables before the spacewalk began, for the astronauts' safety.  Endeavour's crew used the robot arm and thruster rockets Sunday to snap together Zarya and Unity, forming a 77-foot, 35-ton tower in Endeavour's cargo bay. Construction of the space station hinged on making the electrical hookups, said NASA's lead flight director, Bob Castle. Unity, a connecting passageway, needs the solar power generated by the Zarya control module to survive. Working 240 miles above Earth, Ross and Newman had 135 tools at their disposal and a horde of engineers standing by in two countries to offer advice. The spacewalkers tied the most important tools to a pole that jutted from the top of the robot arm ? a floating tool belt. Newman also strapped a set to his waist; the tools stretched out behind him as he used a newly installed slide wire to get from one end of the stack to the other. Newman had the more unwieldy job, Ross the more hand-intensive. It was up to Newman to unclamp the 20- to 30-foot power cables and hand them, one at a time, to Ross to _link_ to the mate on the other side. At times, cables seemed to float every which way ? an octopus, the spacewalkers laughingly called it. The colder the cables, the stiffer they became, making it difficult for Ross to join them. Before locking the connectors together, Ross inspected each end to make sure the dozens of tiny pins inside were not bent or caked with debris. He handled the connectors gently so as not to damage them. Each was numbered so there would be no mistakes. Despite the interfering cold, the work went quickly. ``Looking good man,'' Ross told Newman, ``keep it coming.'' Each man's spacesuit was equipped with a mini jetpack in case their safety lines to the shuttle broke. Endeavour is so loaded that it would be difficult for it to dash after a runaway spacewalker. NASA deliberately picked two pros for the job and, even then, had both men go through 200 hours of training underwater, the closest approximation to weightlessness on Earth. Ross, 50, a husky Air Force colonel, has made four previous spacewalks and also has real construction experience. He worked in a steel mill and did highway construction work back in his college days. The taller, thinner Newman, a 42-year-old physicist, conducted a station- practice spacewalk in 1993. * Radiation fluctuates in magnetosphere SAN FRANCISCO, Dec. 7 (UPI) Radiation levels in Earth's magnetic field, where satellites orbit and astronauts must build the space station, fluctuate much more quickly than scientists previously thought. The radiation comes from electrons in space that are sped up to near the speed of light. These high-speed electrons carry millions of electron-volts, which can cause miniature lightning bolts within satellite circuitry as well as create a hazardous work environment for humans. Now a collection of satellites reveals that the energy pump for these electrons is Earth's magnetic field itself, researchers report today at the fall meeting of the American Geophysical Union, or AGU. It's like a superconducting supercollider in the sky, team leader Geoffrey Reeves described for United Press International. Reeves, a space scientist at New Mexico's Los Alamos National Laboratory, says the findings will help make weather maps and forecasts for space similar to those that satellites now make for Earth's weather. Researchers used to believe the energy came from particles carried in the solar wind. Earth's magnetic field, or magnetosphere, was more or less just a receptacle for that energy, they thought. As a passive p_layer_, its radiation changes would typically occur over weeks or months. Instead, says Reeves, Earth's magnetosphere is a giant particle accelerator. It collects energy from surrounding space, channeling it to whip electrons up into high-energy states in a matter of hours and even minutes. Reeves says the team's data comes from about a dozen satellites. They include spacecraft from the Department of Defense, NASA, and the National Oceanic and Atmospheric Administration (NOAA), as well as instruments aboard some global- positioning satellites. Their presentation before the AGU in San Francisco is the first clear demonstration of Earth's dynamic magnetosphere, he says. The new tools we have are more satellites, he points out. Before, it was like flying one airplane through a tornado once, and then trying to figure out what it was like and where it would go. The space equivalent of tornadoes are geomagnetic storms, such as the 1989 event that overwhelmed Quebec's power grid and plunged most of the Canadian province into darkness for several hours. The source of such storms is ultimately the sun, whose bursts of high-speed solar wind, coronal mass ejections, and shock waves wax and wane in cycles. Terry Onsager, a NOAA space physicist who works to predict space weather and its effects, says the next solar cycle of activity is just beginning. With it, we're seeing not only enhanced activity on the sun, but also in the near-space region and on the ground, Onsager says. What these findings are making clear is that Earth's role in these two areas is much more dynamic than we used to think. The fact that Earth had a magnetosphere was discovered by James Van Allen 40 years ago. Often called the Van Allen belt, its magnetic field lines surround Earth like a doughnut and channel in and out of the planet at its poles. Moving along the field lines are electrons and protons, trapped by their electrical charge. The particles originate from two sources of atoms and molecules: Earth's atmosphere and the sun itself. However, says Reeves, the new data confirms that electrons in the solar wind don't carry enough energy into the magnetosphere to be the engine behind the pumped-up electrons. The solar-wind electrons have energies of roughly 2,000 electron-volts apiece. The high-speed electrons, on the other hand, each carry a charge of several million electron-volts the equivalent of nearly one million 9- volt batteries wired together. This discrepancy in energy means that the Earth's magnetosphere is somehow collecting other forms of energy from the sun and channeling it to the electrons. The mechanism by which it achieves this particle acceleration is still unclear. That these rapid changes in radiation levels can affect satellites, however, is more clear. Reeves also has data showing a magnetic storm occurred at the same time the Galaxy 4 satellite stranded thousands of pagers last May. Although the satellite had survived such space weather before, Reeves says, this storm could well be a contributing cause of its failure. We are a spacefaring nation now, whether we like it or not, he says. Whenever we make a long-distance phone call, watch television, or use the Internet, there's a satellite somewhere that's likely involved. * Syphilis and gonorrhea down in U.S. DALLAS, Dec. 7 (UPI) The Centers for Disease Control and Prevention says syphilis and gonorrhea have reached all-time lows in the United States overall, but a number of cities in the South and Northeast continue to battle high rates of both diseases. The CDC said today that 15 cities have the highest rates of the two diseases. They are, in alphabetical order, Atlanta, Baltimore, Birmingham, Chicago, Detroit, Memphis, Milwaukee, Nashville, Newark, New Orleans, Norfolk, Oklahoma City, Richmond, St. Louis, and Washington, D. C. Baltimore had the highest rate of both diseases, the CDC said. In a report to the 1998 National STD Prevention Conference in Dallas, the CDC said the new data will help identify areas where increased attention must be focused in the next era of sexually transmitted disease prevention. Dr. Helene Gayle, director of CDC's National Center for HIV, STD, and TB Prevention, said: For far too long, our nation has accepted the consequences of STDs as an unavoidable reality. Fortunately, for the health of women and children, things are beginning to change. But we must gain momentum if we are serious about further reducing the still staggering toll. Gayle said gonorrhea and syphilis are now primarily isolated geographically, but other diseases such as chlamydia, herpes, and human papillomavirus remain extremely widespread. The latest estimates indicated that 15 million Americans become newly infected with an STD each year. Dr. Jeffrey Koplan, CDC director, says syphilis is now confined to only 1 percent of the counties in the United States and has never been more vulnerable to elimination. Although progress is being made against gonorrhea and syphilis, the CDC said it receives more reports of chlamydia each year than any other infectious disease. The disease often has no symptoms and often goes undiagnosed. It can cause severe problems for women, including infertility and potentially fatal tubal pregnancies. The 10 states with the most severe levels of chlamydia among young women ages 15-24 tested in family planning clinics, include Arkansas, 11.2 percent; South Carolina, 11.1; Mississippi 11.0; North Carolina, 10.7; Alabama, 10.6; Louisiana, 10.2; Texas, 8.2; Georgia, 7.6; Illinois, 7.4, and Florida, 7.2. * Surgeon General pushes sex education HONOLULU, Dec. 6 (UPI) The nation's top health officer says Americans have to get real about educating their children about sex. At the interim meeting of the American Medical Association's House of Delegates in Honolulu today, Surgeon General David Satcher urged sex education be used to teach children responsible sexual behavior that includes abstinence where appropriate. Satcher said that in an education vacuum, children learn about sex in all the wrong places: from people on the street, from movies and television shows and from the Internet. People have got to get real about talking to children about sex, Satcher said at the opening session of the AMA meeting at which delegates will tackle numerous policy decisions. Satcher said proper sex education programs can help children and teenagers feel good enough about themselves to be abstinent until they are involved in a committed relationship. He said such education can help protect young girls from older men, often responsible for fathering children of these teenagers. We know that the rates of teenage pregnancy in this country, although they are on the decline, are still higher than any of the developed nations, Satcher said. Yet we refuse to teach sex education. He said there are still a million teenage pregnancies, there are 12 million cases of sexually transmitted diseases and AIDS is growing fastest in American among those in their teens and early 20s. It's time to start putting children first, Satcher said. The surgeon general also said that the states which receive money from the $206 billion tobacco settlement should use that money to prevention children from becoming addicted to tobacco as a first priority. Then he suggested the funds be used to help people quit smoking and also to try and prevent illness in smokers and ex- smokers. * Pacific Rim Smog Degrading Air Quality in U.S. SAN FRANCISCO (Reuters, 7/12/98) ? The United States is importing more than automobiles and VCRs from the Pacific Rim. Smog is crossing the ocean, too. Scientists said Sunday they have documented for the first time that industrial pollution and dust from Asia travels thousand of miles across the Pacific and degrades air quality over the United States. In some cases during the past two years, levels of airborne particles that originated in China and central Asia spread as far as Texas and briefly spiked some U.S. pollution levels as high as two-thirds of federal health standards. However, the pollution is diluted as it hitches a ride on mid-level winds circulating around the globe and poses no real public health threat in most instances, scientists said at the meeting of the American Geophysical Union. In most cases, the concentrations are going to be low, and we could expect very low health impacts, said Dan Jaffe, an atmospheric chemist at the University of Washington-Bothell. But everybody's garbage goes someplace. The Asian pollution transfer occurs mostly in the spring and fall. The international contribution to a metropolitan area's total volume of air pollution remains very small, but could increase as industrialization, rain forest burning and other polluting sources grow, scientists said. I think we're being bombarded on a regular basis, said Douglas L. Westphal, a marine meteorologist with the Naval Research Laboratory in Monterey, Calif. It's much more often than I expected. Scientists presented preliminary data on a pair of instances when satellites spotted signs that large amounts of dust and industrial pollution were rapidly moving across the Pacific towards the United States. The pollution clouds were confirmed by ground-_base_d stations in the western United States. On March 29, 1997, researchers at the Cheeka Peak Observatory in Washington state measured carbon monoxide levels that were 10 percent higher than average and fine particulate levels that were 50 percent higher than average. The station is located in the remote Olympic Peninsula and the pollution levels could not have come from a local source, Jaffe said. And from April 25 to May 2 of this year, huge volumes of dust from the Gobi Desert in Mongolia and other Asian deserts traveled in a cloud across the Pacific, reaching as far east as Texas. In Seattle, Portland and other western U.S. cities, the sky turned milky white from the dust. Mineralogical tests showed the grit originated in Asia. Scientists said dust transport probably always has occurred. It leaps across the ocean on winds in the troposphere to about 20,000 feet, or below the jet stream. The winds travel about 60 mph. Of greater concern to scientists and public health researchers are fine particles of industrial pollution and soot from Asian factories, where pollution controls are not as stringent as in the United States. Burning rain forests is another source of far-ranging soot and combustion chemicals. These particles lodge deeply in the lungs and are believed to be _link_ed to cardiovascular and respiratory disease. Similar intercontinental movements of dust and pollution occur between the United States and Europe and between other continents, but those atmospheric patterns have not been as closely studied. * Inner-city mothers often depressed NEW YORK (Reuters, 7/12/98) ? Up to 40% of inner city women with young children may have symptoms of depression, findings from a US study suggest. Women receiving public assistance and those in poor health are most likely to suffer from depression, according to the researchers who conducted the study. But symptoms of depression in these women often go undiagnosed and untreated, according to Dr. Amy M. Heneghan of Albert Einstein College of Medicine in the Bronx, NY, and colleagues. As a result, women can experience significant psychologic, social, and occupational disability,'' they write. Depressive symptoms in mothers of young children also place children at risk for developmental, behavioral, and emotional problems.'' To determine which inner-city mothers are most likely to be depressed, Heneghan and colleagues gave a brief test designed to diagnose depression to 279 women ? ages 14 to 48 ? who brought their infants and toddlers to an inner city pediatric clinic. They also interviewed the women, asking them about their educational, financial, health, and employment status, and how happy they were. Nearly 40% of the women had test scores suggesting high levels of symptoms,'' they researchers found. And about 20 % of the mothers had scores suggesting major depression. Mothers receiving public assistance, and those who were in poor health ran a higher risk of depression than other mothers, Heneghan and colleagues report. Other sociodemographic indicators ? including race, age, employment and marital status ? were not as closely correlated with depression, they found. These findings suggest that health care providers can identify mothers most likely to be depressed by asking a few questions about their health, and financial situation, or by simply asking, How are things going?'' Heneghan and colleagues suggest. Since most mothers bring their children to the pediatrician on a regular basis ? even if they do not see a doctor regularly themselves ? it is important for pediatricians to know how to identify these women, and refer them to treatment centers, the researchers write. Early treatment could prevent the progression of depressive symptoms into an episode of major depressive disorder,'' they report. * New clue to muscular dystrophy NEW YORK (Reuters, 7/12/98) ? New findings about blood flow during exercise may provide a clue to the cause of muscular dystrophy ? a degenerative disease affecting muscles that results in disability, deformity, and death ? according to a report in the December 8th issue of the Proceedings of the National Academy of Sciences. In experiments with mice, Dr. Gail D. Thomas, of the University of Texas Southwestern Medical Center in Dallas, and colleagues found that neuronal nitric oxide synthase (nNOS), a gas found in healthy muscles, helps keep blood flowing to muscles during exercise by inhibiting the normal process of vasoconstriction ? narrowing of the blood vessels. The researchers injected mice with norepinephrine, a drug that induces vasoconstriction. To simulate exercise, they used electric stimulation to contract the muscle in the animals' hindlimbs. In normal nice, there was less vasoconstriction during muscle contraction, presumably because the muscle released nNOS, the investigators observed. But vasoconstriction was not inhibited in mice that lacked the gene that produces nNOS, or in mice that had muscular dystrophy and therefore had low levels of nNOS. We propose that contraction-induced activation of nNOS plays an important role in the regulation of skeletal muscle blood flow during exercise,'' the authors write. Patients with muscular dystrophy have been found to have low levels of nNOS, the research team explains. The team suggests that, in patients with muscular dystrophy, the reduced levels of nNOS may allow blood vessels to become constricted too often, depriving muscle fibers of blood and oxygen and thus contributing to their destruction. * Kids with ADHD injured more often NEW YORK (Reuters, 7/12/98) ? Children with attention deficit hyperactivity disorder (ADHD) are more likely to be seriously injured than children who do not have ADHD, according to a study in the December issue of Pediatrics. In light of these findings, those who care for children with ADHD should be more vigilant, encourage these children to be more vigilant in potentially dangerous situations, and insist on more consistent use of safety devices such as bicycle helmets,'' the researchers who conducted the study advise. ADHD, characterized by hyperactivity and difficulty in sustaining attention, is one of the most common childhood developmental disorders, note the researchers, led by Dr. Carla DiScala, of Tufts University Medical School, in Boston, Massachusetts. Roughly 1% to 3% of children in the US have been diagnosed with the disorder, which is considerably more common among boys than girls. In their study, DiScala and colleagues reviewed the medical records of children, ages 5 to 14, admitted to more than 70 US hospitals for injuries between 1988 and 1996. The researchers compared the records of those who had ADHD with the records of children who did not have the disorder. Children with ADHD were more likely to be injured while walking than were children without ADHD, the researchers found. In fact, among children with ADHD, pedestrian injuries were the number one cause of injury leading to hospitalization. The increased number of pedestrian injuries among children with ADHD seems to be consistent with the observation that although children with ADHD understand the dangers associated with a situation, they are unable to develop adequate safety responses,'' DiScala and colleagues write. Overall, injuries related to transportation ? such as motor vehicle, pedestrian, and cycling injuries ? were more common among children with ADHD than those without. Nearly 60% of all injuries to children with the disorder were transportation-related, compared with 49.8% of injuries to children without ADHD, the researchers report. In light of these findings , pediatricians and other health care workers should counsel caregivers of children with ADHD about increasing vigilance of behavior in traffic and consistent use of safety devices such as bicycle helmets,'' DiScala and colleagues conclude. * Heroin Use Up Among U.S. Teens CHICAGO (AP, 7/12/98) ? Heroin use has risen rapidly in recent years among U.S. teens, with many middle-class youngsters snorting the drug in the mistaken belief that it's less addictive than shooting up, experts say. The proportion of American 12th-graders who had used heroin doubled between 1990 and 1996, from 0.9 percent to 1.8 percent, according to a study in the December issue of the journal Pediatrics. And the rate edged up again last year, to 2.1 percent, with some states reporting even higher percentages, said the study's author, Dr. Richard H. Schwartz of the Inova Hospital for Children in Falls Church, Va. He cited data from the federal government and other sources. While the overall share of adolescents using the drug remains low, the highly addictive nature of heroin and the devastating consequences of getting hooked make the trend troubling, he said. Dr. Alan I. Leshner, director of the National Institute on Drug Abuse, said the increase in heroin use is similar to that observed for cocaine and appears to be leveling off. ``There's been an increase in purity of heroin on the street, and that increase in purity is drawing a generation of heroin sniffers, snorters, intranasal users, rather than injectors,'' Leshner said. ``They foolishly think if you don't inject it, it's not addicting, which is incredibly wrong. And so you're seeing middle-class, upper middle-class yuppies using heroin, where five years ago, they wouldn't go near it.'' Schwartz said the average price of heroin has dropped by nearly two-thirds, while purity has gone from 10 percent to more than 50 percent. * Teens' Cholesterol Inches Lower WASHINGTON (AP, 7/12/98) ? Teen-agers' cholesterol levels are inching downward, says a study comparing today's teens to those of the late 1960s. The government calls the 4 percent drop impressive because it gives teens a better chance at healthy adulthood. Even so, only one in six children eats a heart-healthy diet. ``The drop ... doesn't necessarily knock your socks off,'' acknowledged Dr. James Cleeman, the study's co-author and the cholesterol coordinator for the National Institutes of Health. ``But if (teens) maintain a seven-point lower cholesterol for a lifetime, that can make a big difference.'' Unfortunately, cholesterol matters even to children. Heart disease is the nation's leading killer, and autopsies of children killed in accidents show its roots are in childhood ? because those kids' arteries already were clogging with the fat. Moreover, other heart risks are on the rise among children: Studies show more and more are overweight, and only about half of teens get enough exercise. The new study, in this month's issue of the journal, Preventive Medicine, used a massive federal health data_base_ to estimate the cholesterol levels and eating habits of children and teens. Cleeman then compared those numbers to earlier studies that measured the cholesterol levels of adolescents ages 12 to 17. The average cholesterol level of today's teens is 160, down from a level of 167 in the late 1960s, Cleeman reported Monday. Every 1 percent drop in people's cholesterol levels translates into a 2 percent to 3 percent drop in the chances a person will have heart disease in the future, he said. So the 4 percent drop in teen cholesterol levels could prove significant ? if this generation of Americans can maintain the lower levels as they age. During the same time period, adults' cholesterol levels dropped by 10 points, but Cleeman couldn't say why adult levels dropped more than the teens'. Heart specialists, however, said doctors stress the importance of lowering cholesterol to adults, so the children's levels may have dropped merely as a side benefit of parents changing a family menu. Teens' daily consumption of fat dropped from 37 percent of their calories in the late 1960s to 34 percent today, and their daily cholesterol intake fell from 350 milligrams to 265 milligrams. ``This is a splendid drop,'' said Dr. David A. Meyerson, a cardiologist at Johns Hopkins University and spokesman for the American Heart Association. But Cleeman also reported that: ?Black teens had cholesterol levels about 6 points higher than whites, and black girls had the highest average level of any demographic group studied, 168. The disparity was puzzling, because black adults generally have lower cholesterol levels than white adults, but Cleeman said black teens also were more likely to be overweight. ?The worst 5 percent of teens had much higher cholesterol levels, reaching 216. ?Only one in six kids meets national dietary guidelines ? limiting daily fat consumption to less than 30 percent of calories; saturated fat to less than 10 percent; and cholesterol consumption below 300 milligrams. Doctors do not recommend giving cholesterol tests to typical kids, unless their parents have super-high cholesterol or early heart disease, Cleeman stressed. That's because cholesterol normally fluctuates at different points in childhood, particularly during puberty. So Monday's take-home message: Parents must instill heart-healthy eating habits in children early, before they hit adolescence and start hanging out at fat- clogging fast-food joints, said the heart association's Meyerson. Infants and toddlers need to eat fat for proper brain development. But parents should start tapering that off after age 2 ? a good time to start switching from whole milk to 2 percent milk and then, in elementary school, even less fatty milk, said Meyerson, who said his own children drink skim milk. A little cake and ice cream is OK every so often, but a bologna sandwich every day or regularly eating hot dogs is too much fat, he said. Improving diet during childhood ``will translate to far fewer heart attacks and strokes in the future,'' Meyerson said. ``The earlier we start (heart disease) prevention, the better it's going to work.'' * It May Be Debilitating Pain Syndrome TRENTON, N.J. (AP, 6/12/98) ? Mary Anne Nelson went through dozens of doctors, surgeries and other painful procedures trying to discover ? and stop ? whatever began ravaging her legs after a skateboard ride left her with a sore foot when she was 14. Most were baffled, some of their treatments made things worse and many tried to convince her parents she was imagining the whole thing. Today, at 37, Nelson is mostly paralyzed from the waist down by a debilitating affliction called Complex Regional Pain Syndrome. Often triggered by a minor nerve injury, and sometimes with no obvious source, the syndrome causes horrible pain, swelling, skin sensitivity, sweating, and discoloration and skin breakdown as circulation deteriorates. Nelson, who lives in Montville, recalls one awful day in 1984 when, with her left leg a swollen purple blob, she said to her doctor: ``Why can't you just amputate it?'' The doctor wouldn't do it, but William Swanson's did 3 1/2 years ago after he sprained his right ankle in a fall at work and his ordeal with the syndrome began. At Swanson's insistence, a surgeon cut off the leg just below the knee after it turned purple. Pain in the amputated leg gradually faded, but after an 18-month respite during which Swanson was finally able to walk with a prosthetic, severe pain returned in the stump and it turned purple again. ``So I'm right back where I was five years ago, still in a wheelchair,'' said Swanson, who lives in Barnegat. He has endured repeated medical complications caused by heavy medications for pain and for depression brought on when his wife left him because of his health problems. While Nelson and Swanson are praying for minor improvement, doctors and therapists who treat patients with CRPS ? previously called Reflex Sympathetic Dystrophy ? say 95 percent of those diagnosed quickly are promptly cured or made better. ``Up to three to four years ago, it was grossly, grossly underdiagnosed,'' said Dr. Wen-Hsien Wu, director of the Pain Management Center at the University of Medicine and Dentistry of New Jersey-New Jersey Medical School in Newark. Physicians have written about patients with such symptoms dating at least as far back as the Civil War, said Dr. James N. Campbell, professor of neurosurgery at Johns Hopkins University School of Medicine in Baltimore. Wu's clinic, one of the nation's first to specialize in the syndrome, sees patients with advanced and complicated cases. The center focuses on ``reducing enough of the pain so they can go on living.'' Treatments include pain killers and muscle relaxers, physical therapy, injections of nerve blockers, morphine pumps implanted in or near the spinal column and electrodes threaded near the spine to block the pain. Wu describes the syndrome as ``a vicious cycle'' that begins with a perhaps- unnoticed ``tiny nerve injury'' amplified when the spinal cord, as if on autopilot, rekindles the pain signal in the limb's sympathetic nerves so that nearby areas are oversensitized. The sympathetic nervous system controls involuntary activities of the glands and organs, including sweating, blood flow, heart rate, bowel and bladder functions, and skin reactions such as goosebumps. Over time, hypersensitivity at the injury site can spread via the spinal cord to other body parts. Hands and feet are most often affected, with patients often unable to wear long pants or shirts, socks or gloves. Many build ``tents'' with their bedding to keep sheets off affected limbs so sensitive to the touch that even a gentle breeze can cause excruciating pain, according to Nancy Just, director of psychological services at Wu's center. Just is directing a study in which some patients will be injected with a drug to stop muscle spasms by blocking nerve signals. That should allow enough pain relief for patients to participate in physical therapy, she said. Campbell isn't convinced. ``It may be that it helps some people in ways that are useful, (but) I don't see this as a big breakthrough,'' he said. Despite the unencouraging prognosis facing them, Nelson and Swanson are hoping for brighter days. Swanson, happy with a new girlfriend, said his medications allow him to do chores around the house and some volunteer work. ``I want to get my health back so I can be a father to my kids,'' now 6 and 4, he said. Nelson regained some use of her legs through rehabilitation. She's waiting for new leg braces that may enable her to walk with crutches. She married eight years ago and her pain gradually decreased after she became paralyzed so she's able to go to physical therapy regularly. ``I'm going to get better,'' Nelson said. ``This is just a long, temporary thing.'' This e-mail address is being protected from spam bots, you need JavaScript enabled to view it