Stories of Modern Science ... from UPI

URBAN AIR POLLUTION LINKED TO BIRTH DEFECTS

Exposure to two common air pollutants may increase the chance that a pregnant woman will give birth to a child with certain heart defects, according to a University of California at Los Angeles study. It provides the first compelling evidence that air pollution may play a role in causing some birth defects, says Beate Ritz, a UCLA epidemiologist. Pregnant Los

Angeles-area women living in regions with higher levels of ozone and carbon monoxide pollution were three times as likely to give birth to children who suffered from serious heart defects. The study is published in the Jan. 1 edition of the American Journal of Epidemiology. The researchers found the risk for the birth defects increased among women exposed to elevated amounts of the pollutants in the second month of their pregnancy -- a period when the heart and other organs begin developing. According to the birth defects registry, one in 33 babies in the United States is born with a serious birth defect, the leading cause of infant death. "These findings show that there are more health problems caused by air pollution than solely asthma and other respiratory illnesses," Ritz says.

MINI-LASERS, NEW TECHNOLOGY LEAD TO SPEEDIER CHIPS

Using light beams in place of metal wires, engineers at The Johns Hopkins University have devised a cost-effective method to speed up the way microchips "talk" to each other. The method takes advantage of unusual characteristics associated with "silicon on sapphire" technology, a new way to manufacture microchips. "We've developed a very fast and cost-effective way of getting data on and off a chip without using wire," says Andreas G. Andreou. "It really promises to revolutionize how computer systems for homes and businesses are put together." Andreou's team relies on the same fiber optics technology that is used to carry phone conversations across great distances. These components are incorporated into a new type of microchip technology. The microchips inside most modern computers are assembled on thin slices of silicon, a material that is a semiconductor. The Johns Hopkins engineers use microchips in which silicon is layered onto thin slices of synthetic sapphire, a material that is an insulator and also allows light to pass through it. In the microsystem devised by Andreou's team, a signal that originates in a wire is transformed into light and beamed through the transparent sapphire substrate via a laser that is only slightly larger than a human hair.

NEW METHOD OF DELIVERING VACCINES

Researchers at University of Texas Southwestern Medical Center in Dallas have developed a quicker, more cost-efficient method of delivering dendritic cell-based vaccines, a discovery that moves anti-tumor vaccines closer to a practical reality. The conventional method to develop vaccines involved extracting dendritic cells, which initiate immune responses to bacteria, viruses and cancer cells, from the body. They were then cultured and expanded in a petri dish, loaded with tumor-associated antigens and finally administered via a vaccine. Dr. Akira Takashima reports in Nature Biotechnology that this expensive and time-consuming process has prevented broader clinical applications for dendritic cell-based vaccines. In the study, Takashima developed and tested a new procedure in mice that enabled researchers to manipulate dendritic cells in the skin rather than in a petri dish. This new process streamlines the conventional method from 10 days to 24 hours. Dendritic cells are specialized white blood cells that signal T lymphocytes, critical components of the immune system, to multiply and initiate an immune response. The epidermis, or outermost layer of normal skin, contains immature dendritic cells known as Langherhans cells. "We thought these Langherhans cells would carry the tumor-associated antigen to the draining lymph nodes and initiate protective immunity against tumor development," says Takashima. "Our subsequent experiments with several tumor models have, indeed, demonstrated the preclinical efficacy of this strategy."

ANNUAL OSCILLATION OF EARTH'S SHAPE

The seasonal movement of water between north and south polar regions regularly stretches and compresses the Earth, according to researchers at the University of Nevada in Reno. Geophysicists analyzing data from the Global Positioning System were initially puzzled when a small annual Earth movement remained after they accounted for known phenomena such as tides and plate tectonics. A careful investigation showed the effect was "hidden in the theory," describing the behavior of an elastic body like the Earth, New Scientist reports. Each winter, snow and soil moisture accumulates in cold polar regions and the atmosphere becomes denser, says Geoffrey Blewett. "The elastic body theory predicts that this extra weight should slightly compress the hemisphere experiencing winter," he says. "In the North, the maximum compression should occur in February or March, when the most water has accumulated." The polar region should then dry out during spring and summer, while moisture settles out at the opposite pole. "The result is an annual oscillation of Earth's shape," says Blewett. "And this is exactly the pattern shown in the GPS data." The northern hemisphere and the southern hemisphere compress, according to Blewett. "The water that 'pushes down' the poles oscillates between the hemispheres."

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MINI-LASERS, call 410 516-7907; about VACCINES, call 214 648-3404.)