Marine toxin can target colon cancer
GAINESVILLE, Fla., Aug. 31 (UPI) -- U.S. researchers say they've modified a toxic chemical produced by marine microbes and successfully tested it against laboratory models of colon cancer.
Chemists at the University of Florida took a generally lethal byproduct of marine cyanobacteria, apratoxin, and made it more specifically toxic against cancer cells, a UF release said Wednesday.
Given in low doses to mice with a form of colon cancer, the compound inhibited tumor growth without the overall poisonous effect of the natural chemical, they said.
"Sometimes nature needs a helping human hand to further optimize these products of evolution to treat human diseases," Hendrik Luesch, a professor of medicinal chemistry at UF's College of Pharmacy, said. "Based on what we learned about apratoxins' mechanism of action, we knew this compound class had great potential for use in anticancer therapies; however, the natural product itself is too toxic to become a therapeutic."
The researchers synthesized several apratoxin compounds that were similar to the original except for slight differences in composition, creating one that proved to be extremely potent against the cancer cells in cultures and in mice.
"Marine cyanobacteria produce a huge diversity of compounds," Luesch said. "About half of anti-cancer drugs are based on natural products. "When we studied the biological effects of apratoxin, we predicted it would be particularly useful against colon cancer if we could engineer it to be more selective."
Solar power brings lead pollution threat
KNOXVILLE, Tenn., Aug. 31 (UPI) -- Solar power, heavily reliant on lead batteries to store the energy it creates, could greatly boost lead pollution in developing countries, U.S. researchers say.
A study led by University of Tennessee researcher Chris Cherry projects lead pollution from expected investments in solar power by 2022 would be equivalent to one-third of current global lead production. The push for solar energy has the potential to release more than 2.4 million tons of lead pollution in China and India, countries heavily involved in lead mining, smelting, battery manufacturing and recycling, the researchers warn.
The battery industry is the largest consumer of lead and is growing rapidly in much of the world to meet demand for batteries for solar power and other applications.
Lead poisoning can cause damage to the central nervous system, the kidneys, the cardiovascular system, and the reproductive system.
The UT study follows reports of a large number of mass lead poisoning incidents around lead battery recycling and manufacturing plants in China.
"The solar industry has to step up and take responsibility for ensuring that their lead battery suppliers are operating with adequate controls as long as they are going to be reliant on this technology," said study co-author Perry Gottesfeld of Occupational Knowledge International. "Without major improvements in the manufacturing and recycling [of] lead batteries in these countries, we expect that lead poisoning will increase as the industry grows."
Astronomers create movies of star births
PARIS, Aug. 31 (UPI) -- New stars emit jets of glowing gas at supersonic speed through space, a process that's now been captured in a "movie" created by U.S. and European astronomers.
Astronomers have looked at still pictures of stellar jets for decades, but now they can watch movies of the phenomena thanks to the Hubble telescope and NASA and European Space Agency scientists.
A team led by astronomer Patrick Hartigan of Rice University has collected enough high-resolution Hubble images over a 14-year period to stitch together time-lapse movies of jets ejected from three young stars, a release from ESA headquarters in Paris said Wednesday.
The moving pictures offer a new take on stellar processes that change and evolve over just a few years, compared with most astronomical processes that change over timescales longer than a human lifetime.
"For the first time we can actually observe how these jets interact with their surroundings by watching these time-lapse movies," Hartigan said. "Those interactions tell us how young stars influence the environments out of which they form.
"With movies like these, we can now compare observations of jets with those produced by computer simulations and laboratory experiments to see which aspects of the interactions we understand and which we don't understand."
Soot's role in climate warming examined
DENVER, Aug. 31 (UPI) -- Cutting soot emissions from diesel engines and other sources could be the fastest, most economical way to slow global warming, a U.S. scientist says.
Mark Z. Jacobson says reducing soot could slow melting of sea ice in the arctic, considered by many as a tipping point for Earth's climate, a point of no return. That's because the ice, which reflects sunlight and heat back into space, would, as it melts, expose darker water that absorbs heat and makes global warming worse, he said at a meeting of the American Chemical Society in Denver.
Jacobson says his calculations show controlling soot could reduce warming above parts of the Arctic Circle by almost 3 degrees Fahrenheit within 15 years, virtually erasing all of the warming that has occurred in the region during the last 100 years, a society release reported Wednesday.
"No other measure could have such an immediate effect," Jacobson said. "Soot emissions are second only to carbon dioxide [CO2] in promoting global warming, but its effects have been underestimated in previous climate models.
"Soot emissions account for about 17 percent of global warming, more than greenhouse gases like methane.
"Soot's contribution, however, could be reduced by 90 percent in 5-10 years with aggressive national and international policies."
Decreasing soot could have a rapid effect, Jacobson explained, because unlike carbon dioxide, which remains in the atmosphere for years, soot disappears within a few weeks.
