Originally created 07/03/97

Smoke cripples cells



Scientists have found genetic damage in the lungs of current and former smokers, strengthening the direct evidence that cigarette smoke causes cancer.

Last year, researchers reported that they had found a precise mechanism that a chemical in cigarette smoke uses to help cripple the genetic material of a cell.

Scientists from the University of Texas M.D. Anderson Cancer Center in Houston searched for cell damage in the lungs of 54 smokers and former smokers who did not have cancer, then did the same with nine people who had never smoked.

This month in the Journal of the National Cancer Institute, they reported that 82 percent of the current smokers and 62 percent of the former smokers showed some genetic alterations in their lung tissue. Similar changes were rare among the nonsmokers. The high rate even in current smokers shows that "genetic damage persists even after smoking cessation."

Warming kills krill

On the surface of the frigid waters of the Antarctic, billions of tiny shrimplike creatures cling to floating ice for their survival.

Now years of global warming are melting that ice, and as the ice dwindles, the population of those creatures, known as krill, is slipping away, according to a report last week in the journal Nature.

Marine biologists studying waters near the South Pole found that krill, a food of blue whales and penguins, are much less prevalent now than they were in the 1970s. In 1977, for example, there were 133,000 krill in every cubic meter of water. The most seen in the past 10 years has been 79,000.

Way cool

Come Saturday night, you may want to put up your hair, put on your boots, and head to the coolest spot you can find.

But you'd have to travel 5,000 light years to get there.

Astronomers have found the coolest spot in the universe. The coldest naturally occurring place lies in the Boomerang Nebula, in the southern constellation Centaurus.

The temperature in this natural refrigerator is about minus 458 degrees Fahrenheit, or 1 degree on the Kelvin scale. Zero degrees Kelvin is absolute zero, the lowest possible temperature.

Raghvendra Sahai of the Jet Propulsion Laboratory in Pasadena, Calif., and Lars-Ake Nyman of the European Southern Observatory discovered the chilly spot by scrutinizing the leftover heat still pervading the universe from the big bang. That residual heat measures just below 3 degrees Kelvin.

Scientists have recently identified peptides that appear to form a natural chemical shield to help protect the skin, lungs and other parts of the body from infection.

Natural peptides are already known to help animals defend against microbes. The first such human compound, named hBD-1, was described in 1995.

Researchers from Germany named their new discovery hBD-2, and it appears to kill the bacteria E. coli and Pseudomonas aeruginosa, as well as a common cause of yeast infection. A peptide is a snippet of amino acids, shorter than a regular-length protein. They reported their findings last week in the journal Nature.

At Johns Hopkins University School of Medicine, researchers studied cystic fibrosis patients. Lung infections with Pseudomonas aeruginosa are a common problem with this disease. The Johns Hopkins team found that a similar peptide, which they named hTAP, protected healthy lung cells, but not lung cells from people with cystic fibrosis. Their work is described in a recent issue of the Federation of European Biochemical Societies Letters.

Heroin-dependent patients reduced their use of the drug by about 90 percent after treatment with a medication similar to methadone, Johns Hopkins University researchers have reported.

The study, published last week in the Journal of the American Medical Association,tested levomethadyl acetate hydrochloride, or LAAM, in 180 heroin-dependent volunteers.

By comparing three dosages, the researchers showed that LAAM was increasingly effective with increasing doses. After 16 weeks of treatment, patients at the highest dose had decreased their heroin use to an average of 2.5 days out of 30 days, compared with an average of 29 days out of 30 before treatment.

LAAM, approved by the Food and Drug Administration in 1993, needs to be taken only three times a week. Researchers believe that it offers advantages over methadone, a widely used heroin treatment, which needs to be taken daily.

Hookworm infections appear to have dramatically increased in Haiti as a direct result of the country's deforestation, researchers are reporting.

Intestinal parasites are common in the impoverished Caribbean nation, but hookworm infection has traditionally been rare. However, beginning in 1990, the prevalence of hookworms among young children in one Haitian community increased from zero percent to about 12 to 15 percent in 1996.

Reporting in the current issue of Emerging Infectious Disease, researchers from the University of Alabama at Birmingham and the Centers for Disease Control and Prevention noted that forests around the community studied were wiped out.