Here is the latest American Chemical Society (ACS) Office of Public Affairs Weekly PressPac with news from ACS’ 34 peer-reviewed journals and Chemical & Engineering News.
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Please cite the individual journal, or the American Chemical Society, as the source of this information.
Journal: Environmental Science & Technology
Journal Article: “Differential Toxicity of Carbon Nanomaterials in Drosophila: Larval Dietary Uptake is Benign, but Adult Exposure Causes Locomotor Impairment and Mortality”
A new study raises the possibility that flies and other insects that encounter nanomaterial “hot spots,” or spills, near manufacturing facilities in the future could pick up and transport nanoparticles on their bodies, transferring the particles to other flies or habitats in the environment. The study on carbon nanoparticles — barely 1/5,000th the width of a human hair —is scheduled for the Aug. 15 issue of ACS’ Environmental Science & Technology, a semi-monthly journal.
David Rand and Robert Hurt and colleagues note that emergence of a nanotechnology industry is raising concerns about the potential adverse health and environmental effects of nanoparticles. These materials show promise for use in a wide range of products, including cosmetics, pharmaceuticals, and electronics.
The study focused on determining how different kinds of exposure to nanoparticles affected larval and adult fruit flies. Scientists use fruit flies as stand-ins for humans and other animals in certain kinds of research. There were no apparent ill effects on fruit fly larvae that ate food containing high concentrations of nanoparticles. However, adult flies died or were incapacitated when their bodies were exposed to large amounts of certain nanoparticles. During the experiments, the researchers noted that contaminated flies transferred nanoparticles to other flies, and realized that such transfer could also occur between flies and humans in the future. The transfer involved very low levels of nanoparticles, which did not have adverse effects on the fruit flies. Since larvae can tolerate very high doses of nanoparticles in the diet, but adult flies show very different sensitivities, the environmental impact depends on the ecological context of nanoparticle release.
In a finding that challenges the increasingly popular belief that smoking marijuana is less harmful to health than smoking tobacco, researchers in Canada are reporting that smoking marijuana, like smoking tobacco, has toxic effects on cells. Their study is scheduled for the Aug. 17 issue of ACS' Chemical Research in Toxicology, a monthly journal.
Rebecca Maertens and colleagues note that people often view marijuana as a “natural” product and less harmful than tobacco. As public attitudes toward marijuana change and legal restrictions ease in some countries, use of marijuana is increasing. Scientists know that marijuana smoke has adverse effects on the lungs. However, there is little knowledge about marijuana's potential to cause lung cancer due to the difficulty in identifying and studying people who have smoked only marijuana.
The new study begins to address that question by comparing marijuana smoke vs. tobacco smoke in terms of toxicity to cells and to DNA. Scientists exposed cultured animal cells and bacteria to condensed smoke samples from both marijuana and tobacco. There were distinct differences in the degree and type of toxicity elicited by marijuana and cigarette smoke. Marijuana smoke caused significantly more damage to cells and DNA than tobacco smoke, the researchers note. However, tobacco smoke caused chromosome damage while marijuana did not.
At a time when water supplies are scarce in many areas of the United States, scientists in Minnesota are reporting that production of bioethanol — often regarded as the clean-burning energy source of the future — may consume up to three times more water than previously thought. Their study appeared in ACS’ journal Environmental Science & Technology.
Sangwon Suh and colleagues point out in the study that annual bioethanol production in the U.S. is currently about 9 billion gallons and note that experts expect it to increase in the near future. The growing demand for bioethanol, particularly corn-based ethanol, has sparked significant concerns among researchers about its impact on water availability. Previous studies estimated that a gallon of corn-based bioethanol requires the use of 263 to 784 gallons of water from the farm to the fuel pump. But these estimates failed to account for widely varied regional irrigation practices, the scientists say.
The scientists made a new estimate of bioethanol’s impact on the water supply using detailed irrigation data from 41 states. They found that bioethanol’s water requirements can be as high as 861 billion gallons of water from the corn field to the fuel pump in 2007. And a gallon of ethanol may require up to over 2,100 gallons of water from farm to fuel pump, depending on the regional irrigation practice in growing corn. However, a dozen states in the Corn Belt consume less than 100 gallons of water per gallon of ethanol, making them better suited for ethanol production. “The results highlight the need to take regional specifics into account when implementing biofuel mandates,” the article notes.
In an advance that could help ease the antibiotic drought, scientists in Massachusetts are describing successful use of a test that enlists pinhead-sized worms in efforts to discover badly needed new antibiotics. Their study appeared in ACS Chemical Biology, a monthly journal.
Frederick Ausubel and colleagues note in the new study that existing methods for identifying germ-fighting drugs involve adding the potential drug to cultures of bacteria or cells and watching the results. These tests sometimes do not work well. They may give passing grades to potential drugs that are toxic, or that fight bacteria in the same ways as existing antibiotics that are loosing effectiveness against drug-resistant bacteria. A much better test would involve screening of potential new antibiotics in living animals infected with bacteria to see the effects on the entire body of the animal.
The scientists describe successful use of such a whole-animal high throughput screening test — automated with a robot — to test the effects of 37,000 potential drugs on C. elegans (a type of worm) infected with E. faecalis (a type of bacteria). That bacterium causes life-threatening infections in humans. C. elegans are tiny nematode worms that are widely used in scientific research. The tests identified 28 potential new drugs never before reported to have germ-fighting effects. Some of the potential new drugs worked in ways that appeared to be totally different than existing antibiotics.
Growing scientific evidence indicates that people who adhere to a special calorie-restricted diet can improve their health and could potentially add years to their lifespan, according to an article in the current issue of Chemical & Engineering News, ACS’ weekly newsmagazine.
C&EN contributing editor Laura Cassiday notes in the article that researchers have known for decades that calorie restriction — reducing calorie intake without compromising nutrition — slows aging, extends lifespan, and fights disease in animals. Mice fed a calorie-restricted diet, for example, had a 30 percent increase in lifespan, while calorie-restricted monkeys were healthier and had a three-times lower rate of death from age-related causes than controls, the article notes. Recent studies suggest that people on these diets may gain similar benefits.
But scientists are unclear exactly why or how caloric restriction works. Scientists believe, however, that it may work by blocking an important chemical signaling pathway in the body, called the TOR pathway, that helps control cell growth. Other signaling pathways may also be involved, researchers say. For those who can’t adhere to a strict low-calorie diet, some pharmaceutical companies are attempting to develop drugs that mimic the effects of caloric-restriction without requiring drastic changes in eating habits. Scientists appear to be moving ever closer to the elusive Fountain of Youth, the article suggests.
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PressPac information is intended for your personal use in news gathering and reporting and should not be distributed to others. Anyone using advance PressPac information for stocks or securities dealing may be guilty of insider trading under the federal Securities Exchange Act of 1934.
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 154,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.