Monthly Archives: September 2012

27 September 2012 Last updated at 13:20 ET

Police forces in England and Wales have begun a large-scale operation to collect DNA samples from about 12,000 serious offenders who are not on the national DNA database.

Operation Nutmeg will see officers collect swabs from sex offenders and murderers living in the community.

Criminals are often not on the database if they were convicted before 1994, when sample-taking became routine.

The scheme has been launched after a successful pilot exercise in Hampshire.

Police hope the collection of thousands of new samples could help to solve so-called cold-cases, where a new sample is linked to a past crime.

Speaking at a briefing on Thursday, Amanda Cooper, director of information, science and technology at Thames Valley Police, said officers would approach individuals between now and next summer to collect the samples.

Police forces have been given lists of offenders living in their areas and will work though them to collect the samples.

The lists have been drawn up based on information from the Police National Computer, which was first used in the 1970s.

Alex Marshall, the chief constable of Hampshire police, said 167 samples were taken from a list of 471 convicted criminals during the pilot operation.

Continued here:
New drive to take criminals' DNA

In the first study of its kind, researchers have discovered that male DNA is commonly found in the brains of women a finding that could hold important implications for diseases like Alzheimers disease and cancer.

Male DNA is likely transferred to female brains during pregnancy, according to researchers from the Fred Hutchinson Cancer Research Center in Seattle. During this time, mothers and fetuses exchange and harbor genetic material and cells in a phenomenon called microchimerism.

This means, if a mother is pregnant with a boy, she will end up with male DNA in her system potentially for the rest of her life. If the fetus is female, the mother will end up with genetic material from her daughter, though it is difficult for researchers to distinguish between two sets of female DNA in microchimerism studies.

What this means for treating diseases

Prior studies have observed fetal DNA in many other of the mothers tissues and organs, but this is the first to confirm fetal cells can cross the blood-brain barrier and reside in the mothers brain beyond pregnancy.

We were interested in looking at the human brain because its never been looked at before, and it was really unknown if the cells of fetal origin could reach the brain, study senior author Dr. Lee Nelson, a member of the Fred Hutchinson Cancer Research Center and professor of medicine at the University of Washington, told FoxNews.com. Nelson and her colleagues performed autopsies on 59 brains of deceased females and detected male microchimerism in 63 percent of them.

Male microchimerism was distributed across multiple regions of the female brain, including those affected by dementia, and could persist for decades potentially even an entire human lifespan. According to the study, the oldest female with microchimerism detected in her brain was 94.

The question naturally arises what role might the cells have in benefiting health and what role they play in diseases, Nelson added.

The researchers hope further studies on microchimerism might shed new light on various diseases that affect the brain, such as Alzheimers, Parkinsons or even brain tumors.

These cells have access to the brain could help us understand different treatment options for diseases that arent well treated, Nelson said. Its a very exciting new area that opens up different possibilities, such as, what if these cells have anti-tumor potential? For example, glioblastomas are deadly tumors, (which) have poor treatment options. Were very much in need of new potential options.

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Many female brains contain male DNA

By Melissa Lee Phillips, ScienceNOW

Giving a whole new meaning to pregnancy brain, a new study shows that male DNA likely left over from pregnancy with a male fetus can persist in a womans brain throughout her life. Although the biological impact of this foreign DNA is unclear, the study also found that women with more male DNA in their brains were less likely to have suffered from Alzheimers disease hinting that the male DNA could help protect the mothers from the disease, the researchers say.

During mammalian pregnancy, the mother and fetus exchange DNA and cells. Previous work has shown that fetal cells can linger in the mothers blood and bone for decades, a condition researchers call fetal microchimerism. The lingering of the fetal DNA, research suggests, may be a mixed blessing for a mom: The cells may benefit the mothers health by promoting tissue repair and improving the immune system but may also cause adverse effects, such as autoimmune reactions.

One question is how leftover fetal cells affect the brain. Researchers have shown that fetal microchimerism occurs in mouse brains, but they had not shown this in humans. So a team led by autoimmunity researcher and rheumatologist J. Lee Nelson of the Fred Hutchinson Cancer Research Center in Seattle, Washington, took samples from autopsied brains of 59 women who died between the ages of 32 and 101. By testing for a gene specific to the Y chromosome, they found evidence of male DNA in the brains of 63 percent of the women. (The researchers did not have the history of the womens pregnancies.) The male DNA was scattered across multiple brain regions, the team reports online today in PLoS ONE.

Because some studies have suggested that the risk of Alzheimers disease (A.D.) increases with an increasing number of pregnancies, the team also examined the brains for signs of the disease, allowing them to determine whether A.D. correlated with the observed microchimerism. Of the 59 women, 33 had A.D. but contrary to the teams expectation, the women with A.D. had significantly less male DNA in their brains than did the 26 women who did not have A.D..

Whether that correlation means that fetal male DNA helps protect women against A.D. is unclear, however. To me, this suggests that the presence of fetal cells in the female brain prevents disease, says cardiologist Hina Chaudhry of Mount Sinai School of Medicine in New York City.

In a study published online in Circulation Research late last year, Chaudhry and colleagues found that fetal cells in mice migrated to the mothers heart, differentiated into functioning cardiac cells, and accelerated repair to damaged heart tissue. So, Chaudhry says, a similar thing could be happening when fetal cells migrate to the brain. I would bet these cells are getting into the maternal brain and are able to differentiate into neurons.

A 2010 study in Stem Cells and Development showed that fetal cells can migrate to the brain of a mother mouse and mature into neurons, Nelson says. But, she adds, it remains unclear if something similar is happening in humans and its also difficult to reach any firm conclusions about a potential link between microchimerism and A.D. Part of the problem is that her team had little information about the pregnancy histories of the women in their study. We have to say we really dont know, she says. I hope that kind of work can be done in the future, but its very difficult to do with human samples.

This story provided by ScienceNOW, the daily online news service of the journal Science.

Excerpt from:
Bearing Sons Leaves Male DNA Traces in Mom's Brain