Carbon-dating may work for human cells, too
AGING
STUDY'S PURPOSE: Researchers wanted to learn how different types of cells age and whether all cells are replaced during a person's lifetime. Better understanding how cells grow old and when they are replaced would help scientists devise strategies to replace cells that are lost to degeneration and disease.FINDINGS: Atmospheric levels of the carbon isotope 14C -- long used by archeologists to date artifacts -- peaked in the 1950s and 1960s because of nuclear weapons testing. That carbon, absorbed by human cells, can be used to date the individual cells. An international team of researchers in Sweden and the United States analyzed the amount of 14C in human DNA to estimate the age of intestine, muscle, and brain cells. Although cells in most areas of the body were regenerated, they found that brain neurons were not replaced after birth.
BOTTOM LINE: Understanding how cells age and how frequently they turn over in healthy individuals will help researchers figure out what goes wrong in a number of aging related diseases.
CAUTIONS: The topic of whether the brain generates neurons after birth is rather controversial. These findings are based on the analysis of only two brain regions from 10 individuals; it is possible that cellular regeneration may occur in other brain areas. WHAT'S NEXT: As people born in the 1950s and 1960s get older, this technique will become increasingly useful for understanding how dementia and other diseases of aging affect tissues. Researchers will also want to find out whether cells are replaced in response to injury or disease.
WHERE TO FIND THE STUDY: Cell, July 15, 2005.
ZARA HERSKOVITS
PARKINSON'S DISEASE
Medications linked to compulsive gambling
STUDY'S PURPOSE: Over the last three years, neurologists at the Mayo Clinic noticed that a number of their patients with Parkinson's disease were gambling. Some of these patients had never gambled before, while others -- such as a 54-year-old married pastor -- did not fit the usual profile for a compulsive gambler.
FINDINGS: Eleven patients who developed pathological gambling habits were all taking dopamine agonists, a class of medications that stimulates certain receptors on the surface of brain cells. When eight of the patients discontinued their medications, they stopped gambling.
BOTTOM LINE: Doctors and family members of people taking Parkinson's medications should be on the lookout for signs of addictive gambling, and bring any concerns up with their doctor.
CAUTIONS: Pathologic gambling is a rare side effect of dopamine agonists, affecting less than 2 percent of patients who take these medications.
WHAT'S NEXT: Researchers want to examine whether other addictive behaviors such as compulsive eating, increased alcohol consumption, and hypersexuality are also increased by taking these medications. They also plan to investigate whether genetic differences in dopamine receptors can predict which patients develop these side effects.
WHERE TO FIND THE STUDY: Archives of Neurology, July 14, 2005, available online at http://archneur.ama-assn.org/cgi/content/full/62.9.noc50009v1.
ZARA HERSKOVITS
ENVIRONMENT
Seabirds carry pollutants to the Arctic
STUDY'S PURPOSE: A team of Canadian researchers wanted to know how pollutants such as mercury and DDT are getting to the Arctic. Others suspected wind currents, but the researchers thought Arctic seabirds might be involved.
FINDINGS: Arctic seabirds pack a not-so-healthy dose of industrial contaminants in their guano. While researchers have previously observed that pollutants concentrate along the food chain in fish and other animals, this study is one of the first to implicate birds in the trafficking of industrial contaminants from ocean to land.
BOTTOM LINE: This research shows that seabirds can transport pollutants, and it is likely that this will be a problem in other regions. ''These chemicals have a global distribution -- they don't observe international boundaries," said Jules M. Blais, the study's lead author.
CAUTIONS: The study focused on 11 ponds in the Cape Vera region of the Arctic, and more research will need to be done to see whether pollutant trafficking occurs similarly in other ecosystems.
WHAT'S NEXT: Researchers will follow what happens to these chemicals after they have passed through seabirds, in hopes of understanding how humans can avoid contact with these chemicals.
WHERE TO FIND THE STUDY: Science, July 15, 2005.
ZARA HERSKOVITS
FOLKLORE
Native tales may referto tsunami of 1700
STUDY'S PURPOSE: University of Washington's Ruth Ludwin wanted to determine if stories told by natives in the Pacific Northwest about battles between mythological creatures Thunderbird and Whale relate to actual seismological events such as earthquakes, landslides and tsunamis.
FINDINGS: Folktales in numerous native languages from northern California to Vancouver describe floods and earth-shaking caused when the Thunderbird battles the Whale, frequently in an attempt to help humans. Nine stories told between 1860 and 1964 contained enough detail to be traced to a January 1700 earthquake and tsunami nearly as strong as the one that struck Asia last December. Tribal elders continued to avoid places flooded in the folktales into the second half of this century.
BOTTOM LINE: Native populations developed an oral tradition to pass on warning about earthquakes and the tsunamis that sometimes follow them in an earthquake-prone region. ''These past earthquakes had profound effects on the local inhabitants," Ludwin said.
CAUTIONS: The research is necessarily speculative, relying on Ludwin's interpretation of the metaphors in diverse folktales.
WHAT'S NEXT: Ludwin is studying folktales that may refer to killer whirlpools such as the one about a monster who ''when he opens his mouth, water flows into it."
WHERE TO FIND IT: Seismological Research Letters, March/April 2005. Online at www.pnsn.org, click on ''news."
SCOTT ALLEN 
