Oxidative stress is a process in which "free radicals" in the body damage DNA, including telomeres.

Scientists have identified the first direct link between stress and aging, a finding that could explain why intense, long-term emotional strain can make people get sick and grow old before their time, psychport.com reported.
Chronic stress appears to hasten the shriveling of the tips of the bundles of genes inside cells, which shortens their life span and speeds the body's deterioration, according to a small, first-of-its-kind study involving mothers caring for chronically ill children.
"There is this deeply held belief that stress leads to premature aging. But there is no hard evidence for how this might happen," said Elissa Epel, a psychiatrist at the University of California at San Francisco (UCSF), who helped conduct the research.
While cautioning that the findings need to be confirmed by additional research, other scientists said the results represent an unprecedented step in deciphering the intricacies of the mind-body connection.
"This is a real landmark observation," said Robert M. Sapolsky of Stanford University, who wrote a commentary accompanying the paper in today's issue of the Proceedings of the National Academy of Sciences.
The new study "demonstrated that there is no such thing as a separation of mind and body -- the very molecules in our bodies are responsive to our psychological environment."
Epel and her colleagues studied 39 women ages 20 to 50 who had been experiencing grinding stress for years because they were caring for a child suffering from a serious chronic illness, such as autism or cerebral palsy, and 19 other very similar women whose children were healthy.
The researchers examined structures inside cells called telomeres. Telomeres are the caps at the ends of chromosomes--the molecules that carry genes. Every time a cell divides, telomeres get shorter. In the natural aging process, the telomeres eventually get so short that cells can no longer divide, and they then die.
As more and more cells reach the end of their telomeres and die, the inexorable process produces the effects of aging--muscles weaken, skin wrinkles, eyesight and hearing fade, organs fail, and thinking abilities diminish.
The researchers also measured levels of an enzyme called telomerase, which helps rebuild telomeres to stave off this process. Telomerase levels naturally decline with age.
The researchers found that chronic stress appears to accelerate this process. The longer a woman had been caring for a sick child, the shorter her telomeres, the lower her levels of telomerase and the higher her levels of "oxidative stress." Oxidative stress is a process in which "free radicals" in the body damage DNA, including telomeres.
A key factor appears to be people's perception of how much stress they are under, the researchers found. The greater a woman's perception of her stress in the study, the worse she scored on all these factors. Compared with women with the lowest levels of perceived stress, women with the highest perceived stress had telomeres equivalent to someone 10 years older, the researchers found.
It is unclear exactly how stress might affect telomeres and telomerase levels, but it could be that chronically elevated levels of stress hormones such as cortisol damage the telomeres and other genes in the body and lower telomerase levels, inhibiting the cells' ability to respond.

In the future, the phrase smarty pants might be taken quite literally, referring to trousers embedded with electronic "intelligence" so that they change color, for example, in response to their surroundings, brightsurf.com said.
The timing of this vernacular twist will depend on when plastic "chips" become practical--so cheap and reliable that electronic circuits can be printed not only on clothing but also on paper, billboards and nearly anything else. Unlike today's largely silicon-based technologies, organic (carbon-based) materials are flexible, can be processed at low temperatures and lend themselves to large-area applications, such as wall-sized electronic murals.
Before the emerging field of organic electronics can deliver on its commercial promise, however, new measurements, standards and processing capabilities must be developed.
Unfortunately, the job of filling this void is especially challenging. The range of potential materials for organic electronics--from polymers to nanocomposites--is enormous. The number of synthesis and processing methods under consideration is also daunting.
Accurate, reliable measurements will help solve current manufacturing issues and speed widespread use of the new microchips. Ultimately, says Lin, National Institute of Standards and Technology (NIST) plans to develop an "integrated measurement platform."
The envisioned tool will allow scientists and engineers to predict the performance of organic electronic devices based on composition, structure and materials properties.

Psychological stress may be enough to age a woman's chromosomes by 10 years, a new study suggests.
According to New Scientist, the link between stress, ageing and health at the cellular level is unclear, but a team led by Elissa Epel of the University of California at San Francisco, US, has now looked at the effect of stress on the cell.
A piece of DNA called a telomere caps the ends of each chromosome, protecting those ends and promoting genetic stability. Each time a cell divides, the telomeres shorten so that daughter cells have slightly shorter telomeres than their parents.
But in young people, an enzyme called telomerase corrects the process, regenerating the ends. However, in older people the telomeres shorten significantly and eventually their replication stops altogether.
To study the effect of stress on the cell, Epel and her colleagues looked at the chromosomes in the white blood cells of 58 mothers, two-thirds of whom had chronically ill children. The other women had healthy children so may be expected to suffer less stress.
There was no difference in the telomere length of the two groups, but women in both groups who reported the most stress also had the shortest telomeres. And the effect was so large that it represented nine to 17 years' worth of cell ageing.