the-BA : Science News Digest

Children looking surprised (image copyrigh: istockphoto.com)

In the news this week: cloned immune cells clear a patient’s cancer, meteorites that could offer clues to the origins of life and the solar system, and the science of why we scream…

A patient whose skin cancer had spread to his lungs and groin has become the first person to benefit from a new treatment involving his own immune cells. The 52-year-old’s cancer had failed to respond to conventional treatments, but within 2 months of undergoing the experimental therapy his tumours were undetectable. Two years later, he remained tumour-free, reported the Guardian.

A team at the Fred Hutchinson Cancer Research Centre in Seattle identified that the man’s CD4 T cells – a type of immune cell – naturally attacked a protein found on nearly three-quarters of his cancer cells. The team used cloning techniques to replicate the T cells until there were more than 5 billion of them, and then injected them into the patient. They began attacking the cancer immediately and, interestingly, the rest of the man’s immune system gradually mounted a wider offensive against all the cancer cells.

The researchers, who published their work in the New England Journal of Medicine, believe the technique could be applied to around a quarter of skin cancer patients that have immune cells already primed to attack their tumours. While the results are encouraging, the researchers and clinicians at Cancer Research UK agree that the effectiveness of the therapy would need to be confirmed in a larger study.
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A number of traits and skills are said to differ between men and women – including empathy, aggression, risk-taking and navigation. Now, a new study has found that there are differences in the expression of hundreds of genes in male and female brains and suggests that they may in part influence such traits, potentially via a different architecture of male and female brains.

‘The obvious question to follow is whether or not these signatures of sex in the brain have physiological significance for brain physiology and/or behaviour,’ the researchers wrote in the journal Public Library of Science Genetics.
(Read more in the Times)
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In another brain-related study involving 90 volunteers, researchers from Sweden’s Karolinska Institute found that the brains of gay men shared characteristics with those of straight women, while those of lesbians shared similarities with the brains of heterosexual men.

Brain scans revealed that the brains of heterosexual men and homosexual women were slightly asymmetric – with the right hemisphere slightly larger than the left, whereas those of homosexual men and heterosexual women were not. Likewise, the same similarities were found when the blood flow in the area of the brain responsible for emotion, mood and anxiety, was measured.

The work reported in the Proceedings of the National Academy of Sciences highlights ‘the potential biological underpinning of sexuality’ says the Independent, but the researchers emphasized that the study doesn’t clarify whether the differences in brain shape are inherited or caused by exposure to hormones such as testosterone in the womb, nor whether they are responsible for sexual orientation.
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According to research published in Nature Neuroscience, the ‘hunger hormone’ ghrelin may play a role in comfort eating. In both humans and mice, the levels of ghrelin in the gut rise when they don’t eat, sending increased hunger signals to the brain. Experiments in mice have now shown that levels of the hormone also increase in response to stress, apparently helping to combat the depression and anxiety that stress can cause.

‘Our findings in mice suggest that chronic stress causes ghrelin levels to go up and that behaviours associated with depression and anxiety decrease when ghrelin levels rise,’ lead researcher Dr Jeffrey Zigman of the University of Texaz Southwestern Medical Centre in Dallas told the Times. ‘An unfortunate side-effect is increased food intake and body weight.’

Another member of the team, Michael Lutter, added: ‘Our findings support the idea that these hunger hormones don’t do just one thing. Rather, they coordinate an entire behavioural response to stress and probably affect mood, stress and energy levels.’
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The Telegraph reported findings presented at The Endocrine Society’s 90th Annual Meeting in San Francisco that suggest some men could benefit from ‘testosterone replacement therapy’.

A study of almost 2,000 men aged between 20 and 79 indicated that men with low levels of the hormone were 2.5 times more likely to die during the next 10 years than men with higher levels. Testosterone deficiency becomes more common with age. Low levels of testosterone are linked with metabolic syndrome that increases the risk of heart disease, stroke, type 2 diabetes, and other health problems such as depression, loss of bone and muscle mass, and decreased sex drive.

Other research presented at the meeting showed that treatment with a slow-release, injectable form of testosterone for a year led to progressive improvements – significantly reducing waist circumference, lowering ‘bad’ cholesterol, triglycerides (fats) and body fat, and increasing ‘good’ cholesterol. While the researchers concluded that it was worth treating elderly men for testosterone deficiency, they highlighted that it was important to first exclude any suspicion of prostate cancer as the treatment could aggravate it.
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The Independent revealed that scientists have found the first evidence of complex organic compounds in meteorites that are essential components of DNA and RNA. Uracil and xanthine, precursors of nucleobases that make up genetic material, were discovered in the Murchison meteorite that landed in Australia in 1969. It is already known to contain sugars and phosphates that are also essential components of the self-replicating molecules.

Researcher Professor Mark Sephton of Imperial College London, said: ‘At the compound-class level, you have all the basic components needed to make the building blocks of DNA in a single meteorite. It’s not the complete jigsaw to explain the origin of life, but it is the partial jigsaw. This discovery lends weight to the idea that the building blocks of life came from space.’

Lead author of the Earth and Planetary Science Letters journal article, Dr Zita Martins, added: ‘Because meteorites represent leftover materials from the formation of the solar system, key components for life – including nucleobases – could be widespread in the cosmos.’
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Another important meteorite has been purchased by London’s Natural History Museum. The Ivuna meteorite, that landed in Tanzania in 1938, has an extremely rare make-up. Only nine of the 35,000 known meteorites have the same composition, which matches that of the Sun. The stone was split into samples, most of which are held by the Tanzanian government or in private collections. The UK sample, which could hold clues to the birth of the Solar System, will now be studied in detail.

It’s a particularly important specimen to science because it’s been so well preserved,’ Natural History Museum meteorite curator Dr Caroline Smith told BBC News. ‘We’re all incredibly excited about it because it’s so pristine.

‘These types of meteorite are very susceptible to alteration on Earth. Changes in humidity, for example, can change their composition. But this meteorite is important as it fell relatively recently and has been kept under nitrogen in a sealed environment for the last two or three decades.’
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Environment Minister Phil Woolas, would like to look at GM crops as a potential way to help the developing world out of the current food price crisis. He wants further debate on the issue and examination of the benefits that such crops could offer, such as higher yields.

The Independent reported that Ministers had told the paper that ‘rocketing food prices and food shortages in the world's poorest countries mean the time is right to relax Britain's policy on use of GM crops.’

In 2004 it was decided after a heated public debate that commercial production would be assessed on a case-by-case basis, and approval would be granted if evidence showed that there was no risk to human health or the environment.

According to the Independent, ‘Those ministers who favour a renewed push believe there are no scientific arguments against the idea. They argue that Britain has a duty to look at the issue on the grounds that boosting production is the best way to reduce global food prices.

‘They want the new debate to focus on the science to avoid a re-run of the one in 2004, when the GM industry was accused of trying to bounce the Government into giving the go-ahead for purely commercial reasons.’
(Read more)
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It is estimated that loggers in the Congo Basin forest ‘destroy an area the size of 25,000 football pitches every week’, reported the Times. But there are plans for a satellite camera that will record the world’s second-largest tropical forest in more detail than ever before – helping politicians and scientists to know where the impact of logging is at its worst and therefore where deforestation efforts should be concentrated. It is expected to be operational by the end of 2010.

Since the huge quantities of carbon absorbed by trees are released when they are cut down, the preservation of forests is a major aim for those trying to reduce carbon emissions.

‘Protecting the rainforest will help us all in the fight against climate change and also the 50 million people who rely on the Congo forests for their livelihoods,’ said Douglas Alexander, the International Development Secretary.
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Other news in brief:

The Principal Investigator of Nasa’s Phoenix Mars lander mission believes the craft may have already found ice. Photographs revealed bright material that was absent a few days later.

‘These little clumps completely disappearing over the course of a few days, that is perfect evidence that it’s ice,’ he said. ‘There had been some question whether the bright material was salt. Salt can’t do that.’
(The Telegraph)
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Six Degrees: Our Future on a Hotter Planet, Mark Lynas’ book about global warming, has won this year’s Royal Society prize for popular science writing.
(BBC News)
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An independent review into the operation of the Science and Technology Facilities council has been announced. It follows widespread concern from the scientific community after the council, responsible for funding UK astronomy and physics, announced a £80 million shortfall in its budget through to 2011 – putting a number of major existing science projects at risk as well as posing a threat to university physics departments. ‘An assessment of where the STFC’s yearly half-a-billion-pound budget should be focussed is currently underway and will be published next month’ reports BBC News.
(Read more in the Times)
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And finally…

New research has revealed that our facial expressions don’t just tell other people how we’re feeling – they actually have a purpose for the individual making them too. Looking frightened – which commonly involves wide eyes and open mouth – actually makes you more alert, according to a study published in the journal Nature Neuroscience. People asked to make this expression had a ‘wider range of vision, faster eye movements and an increased sense of smell as they breathed more rapidly through their nostrils’ reported the Telegraph.

Likewise, an expression of disgust – which commonly involves a wrinkled nose and scrunched up mouth – results in a ‘smaller range of vision and decrease in nasal volume’, therefore reducing your exposure to an offensive sight or sound.

However, while expressions such as these are shared by people all around the globe, according to another recent study not everybody possesses all 19 facial muscles that control expressions.

Everyone has the five core facial muscles that enable us to convey anger, happiness, surprise, fear, sadness and disgust. But it seems ‘some less common facial expressions may be unique to certain people’, says Dr Bridget Waller, a researcher at the University of Portsmouth. For example, the risorius muscle, which controls expressions of extreme fear, is only found in two thirds of people.

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