Vitamin E Study Reveals Clue About Prostate Cancer
For some time now there’s been a widely held--but still unproven--belief that vitamin E and selenium are useful against prostate cancer. Now University of Rochester scientists have uncovered an important clue to how vitamin E might do the job.
By measuring the proteins made by prostate cancer cells exposed to vitamin E in the lab, the researchers found that the vitamin inhibits the protein, or receptor, that attaches to the male hormone androgen. Prostate cancer cells need androgen to keep growing. They also found that vitamin E inhibits another protein, called prostate specific antigen, or PSA, though it’s not known what role PSA plays. (PSA is considered a marker for cancer because a high blood level of it may indicate a malignancy in the prostate gland.)
Selenium did not alter the two proteins. “It may prevent prostate cancer but function by another pathway than vitamin E,” says Shuyuan Yeh, assistant professor of urology and pathology at the University of Rochester School of Medicine and Dentistry in New York. “Different nutrients have different effects, and together they may be more beneficial. Even vitamin E may have multiple functions, but this [discovery] gives us some idea of how it works,” she says.
This finding could lead to advances in prostate cancer treatment as well as prevention. The scientists found that when alpha-tocopheryl succinate, a type of vitamin E, was added to an androgen-blocking chemotherapy drug, the cancer cells grew more slowly than when the drug was used alone.
Proceedings of the National Academy of Sciences 99 (11): 7408-7413
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Lightning Strikes
A clap of thunder or a bright flash may not be fair warning, but it may be all you get before lightning strikes. Unfortunately, most people hesitate too long or don’t know what to do in those moments, making lightning the second-leading cause of storm-related deaths in the United States (after flooding). And although 90% of people struck by lightning each year survive, many are severely injured and permanently disabled.
Since there are so many myths and misconceptions about how to stay safe, meteorological and health experts participating in the Lightning Safety Group established guidelines that have been accepted by various sports, meteorological and medical groups. The guidelines are based on the most recent research and were published in a medical journal for the first time in June.
Among the recommendations is the 30-30 rule: If the time between seeing the flash and hearing the bang is less than 30 seconds, the person should be in, or quickly seeking, a safer location.
The second “30” refers to the all-clear. “You should not resume activities until 30 minutes after the last lightning or thunder,” says Dr. Mary Ann Cooper, associate professor in the department of emergency medicine at the University of Illinois at Chicago and a member of the Lightning Safety Group.
Safer areas include large structures with plumbing and electrical wiring and fully enclosed metal vehicles (cars, trucks, buses and enclosed farm vehicles). It’s important to roll up windows and avoid contact with metal or conducting surfaces outside or inside the vehicle.
Annals of Emergency Medicine June 2002: 39: 660-664
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Quit Smoking, Live Longer
It goes without saying that the earlier you quit smoking the better your chances of living longer. Now an analysis of 15 years of data involving more than 1 million people puts some numbers behind that common wisdom.
Kicking the habit at 45 added about seven years to the lives of both men and women. Men who quit at 55 added 3.4 to 4.6 years to their lives, women who quit at 55 added 4.2 to 5.6 years to theirs. Furthermore, the researchers found that even at 65, quitting could add as much as two years to a man’s life and nearly four years to a woman’s.
“The life extension even at 65 is striking, [suggesting] the resiliency of the body,” says Donald H. Taylor Jr., assistant research professor of public policy at Duke University’s Center for Health Policy, Law and Management in Durham, N.C. However, since death from smoking begins to take its toll on those in their 50s and 60s, it may be that the 65-year-old smoker is more robust to begin with, Taylor says.
The researchers hope that if the well-known risks of the habit haven’t made people quit, the positive message of knowing how many years they could gain by giving it up will be a motivator.
American Journal of Public Health 92 (6): 990-996
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Cheerleader in the Brain
Why do some people hang in there when the going gets tough--and others quit early on? Researchers looking for that inner cheerleader may have found an explanation. Nerve cells in the part of the brain involved with performance appear to fire more strongly as the expectation of a reward approaches. The strength of that signal may vary from one person to another, ultimately explaining why we run the gamut in perseverance--from slacker to obsessive-compulsive.
Researchers at the National Institute of Advanced Industrial Scinece and Technology in Japan monitored the activity of monkeys’ brains while the animals pressed and released bars in response to seeing certain colored shapes on computer screens. When one task was done, a colored bar at the top of the screen became brighter, and the monkeys moved on to the next task. As the bar became brighter, the monkeys knew they were getting closer to their reward.
“We saw a signal [from neurons in the brain] that was getting stronger as the monkeys went through the trials ... then in the final trial it often disappeared,” says Dr. Barry J. Richmond, a coauthor of the study and chief of the section on neural coding and computation at the National Institute of Mental Health. Although Richmond says it was the increasing strength of the cheerleader signal that interested the researchers the most, they also observed that the signal started to wind down as the monkeys got closer to their payoff, a sip of juice. It’s similar to what happens in humans when they think that winning the game is a sure thing and they start to relax. “Sometimes a person relaxes a little too early and they get beaten.”
Science 296 (31): 1709-1711
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Dianne Partie Lange can be reached at diannelange@cs.com.
