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12,746 articles from Guardian Unlimited Science
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FRIDAY 14. NOVEMBER, 2008
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01:06
Obese women 'more likely to miscarry'
Overweight women are more likely to lose a healthy baby, according to a study. The researchers said the findings supported advice that obese women should lose weight before trying to conceive.
"The excess miscarriage rate in overweight and obese women is due to the loss of chromosomally normal embryos," said Inna Landres, of Stanford University School of Medicine. "It's important to identify elevated BMI [body mass index] as a risk factor for miscarriage and counsel those women who are affected on the importance of lifestyle modification."
Landres' team carried out genetic analyses on 204 miscarriages in women with an average age of 35.
Of the 153 women who had a BMI of less than 25, 36.6% had miscarried foetuses with no chromosome defects, either via insertions or deletions of DNA. This compared with 52.9% of the 51 overweight women (with a BMI of more than 25).
The results were presented at the American Society for Reproductive Medicine annual meeting in San Francisco.
One possible cause is insulin resistance, the early stages of type II diabetes, which affects a woman's hormonal state.
Mark Hamilton, who is chairman of the British Fertility Society but was not involved in the study, said obesity was a recognised cause of miscarriage. He added: "This study will aid our understanding of the known association with being overweight and reproductive loss."
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THURSDAY 13. NOVEMBER, 2008
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16:34
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14:00
Overweight women are more likely to miscarry a healthy baby, according to research involving 204 women who had suffered a miscarriage.
The researchers said the findings back up advice that obese women should lose weight before trying to conceive.
"The excess miscarriage rate in overweight and obese women is due to the loss of chromosomally normal embryos," said Dr Inna Landres of Stanford University School of Medicine. "It's important to identify elevated BMI [body mass index] as a risk factor for miscarriage and counsel those women who are affected on the importance of lifestyle modification."
Landres' team carried out genetic analyses of 204 foetuses miscarried by women with an average age of 35.
Of the 153 women with normal body weight (a BMI of less than 25), 36.6% had miscarried foetuses with no chromosome defects – insertions or deletions of DNA. This compared with 52.9% of the 51 overweight women (BMI over 25).
The results were presented at the American Society for Reproductive Medicine annual meeting in San Francisco.
One possible cause of the effect is insulin resistance, which is the precursor of type 2 diabetes. This affects a woman's hormonal state, which could impact the pregnancy. Also, excess adipose (fatty) tissue leads to higher levels of oestrogen and testosterone in the body.
'We are trying to figure out what is a preventable loss of pregnancy, whether it is a natural cause or maternal influence," said co-author Dr Ruth Lathi.
Dr Mark Hamilton at the University of Aberdeen, who chairs the British Fertility Society and was not involved in the study, said obesity is a recognized cause of miscarriage. "It has not been defined if that risk is related to genetic problems for the embryos or the obesity itself is linked to implantation mechanisms," he said.
"This study will aid our understanding of the known association with being overweight and reproductive loss. We need more follow-up studies on this."
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01:07
Fertility treatment does not increase a woman's risk of developing breast cancer, according to a study of more than 25,000 women in the Netherlands.
The large study will help to reassure patients concerned that the powerful hormone doses that are part of fertility treatment might put them at risk of developing the disease in the future.
At the beginning of an IVF treatment cycle, women are given hormone drugs to stimulate their ovaries to produce more eggs so that clinicians can produce fertilised embryos in vitro. These lead to large spikes in oestrogen levels that could promote the development of breast cancer, which is sensitive to the hormone.
The study, carried out by Dr Alexandra van den Belt-Dusebout at the Netherlands Cancer Institute in Amsterdam, compared 18,970 women who had had at least one cycle of IVF treatment with 7,536 women who had not received fertility treatment between 1980 and 1995. They matched these patients to records in the National Cancer Registry.
Of the 378 women who developed breast cancer, 266 were in the IVF group and 112 were in the non-IVF group. After adjusting for known risk factors such as age, the number of children the women had and family history of breast cancer, the team found no statistical difference between the two groups, showing that IVF treatment does not increase a woman's chances of developing breast cancer.
Van den Belt-Dusebout presented her results at the American Society for Reproductive Medicine in San Francisco.
"From 10 years after treatment, breast cancer risk was moderately increased in the IVF group but also in the non-IVF group, compared to the general population," the researchers said.
Meanwhile, two new studies have revealed that women who receive acupuncture at the same time as IVF treatment are no more likely to have a baby.
Both were randomised placebo-controlled trials in which the effect of acupuncture was compared with a sham procedure. Neither the patients nor the clinician evaluating their pregnancy knew who had received the true treatment.
Acupuncture aimed at improving IVF success rates is widely offered by fertility clinics in the UK. In the first of the studies, researchers in Hong Kong split 370 women receiving IVF into two groups. One group received real acupuncture before and after having an IVF embryo implanted into their uterus. The other had the same procedure, except the treatment used retractable needles that did not penetrate the skin.
Of the 185 who received the sham treatment, 91 achieved a clinical pregnancy (foetal heartbeat identified using ultrasound) and 71 had a successful delivery. This compared with 72 clinical pregnancies in the true acupuncture group and 55 live births. The differences between the groups were not statistically significant.
Dr Ernest Ng, in the department of obstetrics and gynaecology at the University of Hong Kong, said that his methodology was the most powerful way of evaluating whether acupuncture was effective. His results are published in the journal Human Reproduction.
In a second study, researchers in Chicago used a similar design in which 124 women received true or sham acupuncture. The control group had their skin punctured by real acupuncture needles, but not at genuine "Qi-lines" on the body.
In the true acupuncture group, 43.9% achieved a clinical pregnancy, compared with 55.2% of the women given the sham treatment. The results were presented at the American Society for Reproductive Medicine's annual meeting in San Francisco yesterday.
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01:07
Farmers in Mexico have been given another reason to grow agave, the cactus-like plant used to produce the country's most potent export. In the bar room equivalent of alchemy, scientists have turned shots of tequila into diamonds.
The surprise use for the national tipple emerged when researchers at the National Autonomous University experimented with making ultra-thin films of diamond from organic solutions, such as acetone and ethanol. The mix that worked best, 40% alcohol and 60% water, was similar to the proportions used in tequila.
Diamond films are extremely durable and heat resistant and can be used to coat cutting tools. By carefully adding impurities to the films, it is also possible to make diamond semiconductors for use in electronic circuits.
Luis Miguel Apátiga, a member of the team, brought a bottle of cheap tequila into the lab to see if it could be turned into diamond. When he heated a shot to 800C it vaporised and broke down into its atomic constituents, producing a fine layer of carbon on nearby metal trays.
Close examination of the films at high magnification revealed that the carbon had formed into crystal structures identical to diamond. Each was around one thousandth of a millimetre across.
"It's true that the fact it's tequila has a certain charm. It's a Mexican product and Mexican researchers developed the project, but a businessman can say to me: 'Great, how pretty! But how can I use it?'," Apátiga said. "It would be very difficult to obtain diamonds for a ring."
The researchers plan to make tequila-based diamonds on an industrial scale from 2011, a move that could see agave growing expand beyond the tequila market.
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01:07
It seems not. After five months of exploring Mars, digging up the soil and making some startling discoveries along the way, the world's favourite interplanetary laboratory has gone off the radar - probably for good.
Earlier this week, Nasa officials finally closed the book on the Phoenix Mars Lander five months, $475m (£308m) and 605 Twitter messages after it first touched down on the red planet.
In a final message at twitter.com/marsphoenix - yes, even interplanetary craft get their own social media accounts these days (even if they are run by a team back on Earth) - Phoenix signed off with a binary representation of the word "triumph".
Veronica McGregor, from Nasa's press office at the Jet Propulsion Lab in Pasadena, California, gave Mars Phoenix its human face through Twitter - and saw its followers grow from 3,000 on landing day to more than 9,000 not long after, principally due to her willingness to respond to questions. "The Twitter audience is both intelligent and incredibly humorous. I think I was entertained by them as much as they were entertained by MarsPhoenix," she told us.
But the Twitter feed also offered news: it had the first public announcement on July 31 of the discovery of water ice: "An ice-containing sample made it into the TEGA oven. I can now say I'm the first mission to Mars to touch and then *taste* the water. FTW!" (The latter being triumphant gamer jargon - "for the win!")
"We've started other Twitter feeds at JPL, and other Nasa centres have also started accounts for their missions," McGregor said. "Personally, I'm continuing to post to @MarsRovers and I'll be starting @MarsScienceLab in the next few days. I'll post occasionally to @MarsPhoenix, too, with science updates and other news."
Over the course of its mission - which lasted five months in total, two more than initially planned - Phoenix took 25,000 images of the Martian landscape, became the first landing craft to taste the ice below the Martian surface and even found perchlorate salts, which left scientists speculating about the possibility of Martian life.
But Nasa's engineers had an off-again, on-again relationship with the machine, having lost contact last month before a brief rally when Phoenix got back in touch on Halloween. Its rise from the ashes did not last long, and communications went quiet again on November 2. This, said experts at JPL, means Phoenix is most likely now frozen beyond the point of repair.
Still, there is a faint glimmer of hope for Phoenix's legion of fans. Although the skies are too dark and the weather too cold for Phoenix to operate during the winter months, it has a special "Lazarus" mode which might see it hibernate through to the spring ... before rising once again to carry on with its mission. FTW!
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WEDNESDAY 12. NOVEMBER, 2008
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19:05
Fertility treatment does not increase a woman's risk of developing breast cancer, according to a study of more than 25,000 women with fertility problems in the Netherlands.
The study will help to reassure patients concerned that the powerful doses of hormones that are part of fertility treatment might put them at risk of developing cancer in the future.
At the beginning of an IVF treatment cycle, women are given a course of hormone drugs to stimulate their ovaries to produce more eggs than usual so that clinicians can produce several fertilised embryos in vitro.
The treatment causes large spikes in oestrogen levels in the body. In theory this could promote the development of breast cancer, which is sensitive to the hormone.
The Dutch study, carried out by Dr Alexandra van den Belt-Dousebout at the Netherlands Cancer Institute in Amsterdam, examined patient records from all 12 IVF clinics in the country between 1980 and 1995.
Her team compared 18,970 women who had had at least one cycle of IVF treatment and 7,536 other women with fertility problems who had not received fertility treatment. They matched these patients to records in the National Cancer Registry to establish whether they had gone on to develop breast cancer.
Of the 378 women who developed breast cancer, 266 were in the IVF group and 112 were in the non-IVF group. After adjusting for known risk factors such as age, the number of children the women already had, the age they began menstruating, family history of breast cancer and body mass index, the team found no statistical difference between the two groups, suggesting that IVF treatment does not increase a woman's chances of developing breast cancer.
Van den Belt-Dousebout presented her results at the American Society for Reproductive Medicine in San Francisco.
"From 10 years after treatment breast cancer risk was moderately increased in the IVF group but also in the non-IVF group, compared to the general population," van den Belt-Dousebout and her colleagues wrote in their presentation, "This may be explained by a lower number of children compared to the general population."
Having children is known to reduce the risk of breast cancer in women.
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17:04
Jeremy Ginsberg is one of the engineers on the Google Flu Trends project
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14:21
Google already has a window into our souls through our internet searches and it now has insight into our ailing bodies too.
The internet giant is using its vast database of individual search terms to predict the emergence of flu up to a two weeks before government epidemiologists.
Google Flu Trends uses the tendency of people to seek online help for their health problems.
By tracking searches for terms such as 'cough', 'fever' and 'aches and pains' it claims to be able to accurately estimate where flu is circulating.
Google tested the idea in nine regions of the US and found it could accurately predict flu outbreaks between seven and 14 days earlier than the federal centres for disease control and prevention.
Google hopes the idea could also be used to help track other diseases. Flu Trends is limited to the US.
Jeremy Ginsberg and Matt Mohebb, two software engineers involved in the project, said: "Patterns in Google search queries can be very informative."
In a blogpost on the project they wrote: "It turns out that traditional flu surveillance systems take one-two weeks to collect and release surveillance data but Google search queries can be automatically counted very quickly.
"By making our estimates available each day, Flu Trends may provide an early-warning system for outbreaks of influenza."
They explained that private information health would be kept confidential. " Flu Trends can never be used to identify individual users because we rely on anonymised, aggregated counts of how often certain search queries occur each week."
A paper on the project has been accepted by the respected journal Nature.
"This seems like a clever way of using data that is created unintentionally by the users of Google to see patterns in the world that would otherwise be invisible," Thomas Malone, a professor at the MIT Sloan school of management, told the New York Times.
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09:15
Professor Sir John Lawton on need to test nanotechnology
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01:14Obituary: Franciscan priest and archaeologist who excavated Christian sites in the Holy Land
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01:03
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00:09
It is good news for the 38-year old German woman who last year received pioneering ovary transplant surgery at the Infertility Centre in St Louis, Missouri. At 2.50pm today her baby daughter was delivered by caesarian section. She weighed in at 7lb 15oz and is 54 centimetres long.
The decision to deliver the baby by c-section at 40 weeks and one day in the pregnancy was not connected with the mother's earlier surgery, according to Dr Sherman Silber who carried out the ovary transplant. The birth is the ninth reported worldwide to use ovary tissue transplanted from one sister to another, although the first to use a whole ovary.
The patient, who has not been identified, suffered early menopause at age 15 and has been infertile ever since. She received the ovary from her identical twin sister who lives in British Columbia. Her sister already has two children.
Dr Silber believes the procedure could benefit women who are about the receive cancer treatment such as chemotherapy which can reduce their fertility. In that case a surgeon could remove an ovary, freeze it until the treatment is over, then re-transplant back into the patient so that her fertility is restored.
Another possibility is for a woman to delay reproduction by putting an ovary on ice until she is ready to have a baby. I'm very sceptical that anyone would want to go through such a drastic procedure for this purpose though. Re-connecting the ovary is a major surgical procedure which of course entails risks - plus there is the much easier alternative of freezing eggs for future use.
The Guardian's Science Weekly podcast will have an interview with Dr Silber in Monday's show.
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TUESDAY 11. NOVEMBER, 2008
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18:48
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13:55
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13:16
Statins, the cholesterol-lowering drugs, are also effective against a common condition that harms women's fertility, according to a clinical trial that compared them with a drug often used to treat the condition.
In the randomised trial, which involved 60 women in Poland, statins improved various symptoms of polycystic ovary syndrome (Pcos) including acne, excess body hair and irregular periods. The drug also lowered the patients' body weight and cholesterol levels.
"There's a growing body of evidence that statins may be very beneficial in the treatment of women with Pcos," said Dr Leszek Pawelczyk at the Poznan University of Medical Science in Poland. "I think that it is a completely new possibility for the treatment of patients."
Pcos affects around one in 10 women in the UK according to the NHS, including Victoria Beckham and Jamie Oliver's wife, Jools. The condition – which is also called Stein-Leventhal syndrome – is associated with multiple cysts in the ovaries. It is the most common cause of ovulation failure leading to infertility in pre-menopausal women.
It leads to irregular hormone levels including typically high levels of testosterone as well as unreliable egg release from the ovaries. Symptoms – which typically begin to appear in late teens or early 20s – include weight gain, acne, irregular or light periods, excess body hair and problems getting pregnant. Many women with the condition suffer very mild symptoms.
Pawelczyk and his colleagues split their 60 patients into three groups at random. All the women had Pcos and none were taking oral contraceptives. Eighteen of them received regular doses of simvastatin (one type of statin), 19 received metformin (a diabetes drug commonly used to treat Pcos) and 23 were given a combination of the two.
After six months on the medications the team found that those on simvastatin had increased their menstruation frequency by 89% compared with a 32% increase on metformin. The two drugs reduced acne by 67% and 59% respectively while the patients' cholesterol levels dropped by 17% and 1%. The two drugs reduced testosterone levels in the patients by 27% and 19% and the body mass index of the two groups of women dropped by 2.2% and 4.3% respectively. Pawelczyk reported his results at the American Society of Reproductive Medicine annual meeting in San Francisco.
"Simvastatin may be a very good option," said Pawelczyk although he stressed that it could not be given to women who were planning to get pregnant, because statins have been associated with birth defects. The results did not show any benefit to giving simvastatin and metformin together.
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12:28
Indonesia today launched a sophisticated new tsunami warning system designed to give coastal residents enough time to flee or seek shelter from an impending tidal wave.
The national system aims to protect the inhabitants of the archipelago's vast coast and prevent a deadly repeat of the 2004 Indian Ocean tsunami that killed 168,000 people in Indonesia alone.
But even as President Susilo Bambang Yudhoyono inaugurated the system in Jakarta, officials conceded it would be several years yet before it is fully complete and the whole coastline protected.
In particular, deep-sea warning buoys have yet to be installed around Bali, Flores and northern Sumatra — which includes Aceh where most lost their lives in the tsunami — with the result that there could be delays in predicting a tsunami and issuing warnings.
However, much of the complex system of sensors, satellite communications and computer modelling is already in place ahead of the 2010 completion target and was able to predict the tidal wave that struck the Sumatran coast last September.
The Boxing Day 2004 tsunami was the result of an earthquake below the seabed measuring 9.3 on the Richter scale. The surge it triggered struck the Banda Aceh coast within 15 minutes, but in the hours that followed the devastating impact left 240,000 dead around the region.
Yet Indonesia, with its 17,000 islands, remains especially vulnerable because it sits on the meeting point of three of the earth's tectonic plates, leaving 60% of the coastline at risk from tsunamis.
The new high-speed warning system connects a series of seabed sensors that detect the earthquakes that may set of a tsunami, information that is relayed to buoys on the surface.
Deep-sea pressure gauges monitor any sudden variations indicating that a tsunami is in motion, data that is enhanced by the notion of the surface buoys that carry global positioning systems.
All the information is relayed by satellite to the tsunami early warning centre in Jakarta, which is connected to 11 regional hubs across Indonesia.
The real advance, though, is that the snippets of information are fed to a computer which evaluates it in conjunction with pre-programmed scenarios that will, within minutes, give a simulation of arrival times and wave heights, enabling fast and accurate warnings to be issued in the event of an emergency.
But even a perfectly working system, which was jointly developed with Germany, can only reduce and not completely eradicate the dangers posed by such a natural catastrophe.
"We are starting the world's most advanced tsunami early warning system able to issue the quickest possible warnings with a high degree of reliability," said Thomas Rachel, Germany's parliamentary state secretary, in Jakarta.
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03:51
In the fading winter gloom as the bitter Martian chill sinks into its metal innards, Phoenix has twittered its last. The plucky robotic lander that launched from Earth on August 4th 2007 and landed on the red planet on May 25th this year has finally come to the end of its mission - nearly doubling its planned operational life of 3 months.
But shutdown had to happen eventually. The probe landed further north than any previous Martian lander and it is no longer receiving enough light during the day to charge its batteries. On top of the shorter days, dustier skies, more clouds and gathering cold have all contributed to its demise.
It has been a busy five months. In that time, Phoenix has sent back more than 25,000 images. It has verified the presence of water-ice under the surface. It has operated the first atomic force microscope ever used on another world. It has found small quantities of salts that could be substrates for life. And it made the puzzling discovery of perchlorate salts.
Phoenix's final twitter read "01010100 01110010 01101001 01110101 01101101 01110000 01101000 <3", the binary code for "triumph". And her controllers added "MarsPhoenix is finally frozen in the Martian arctic plain. Veni, vidi, fodi". If your Latin is rusty that means "I came, I saw, I dug".
The epitaph was the winner of a competition run by Wired to write the catchiest sub-140 character send off for Phoenix. My favourite though - from a certain D. Adams - was "So long and thanks for all the ice".
There is a small chance Phoenix might wake up in spring and phone home though. Watch this space.
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01:38
Using frozen rather than freshly collected embryos during IVF treatment reduces the risks of stillbirth and premature delivery, according to three separate studies published yesterday.
The findings, from the US, Finland and Australia, suggest the act of stimulating a woman's ovaries with powerful drugs and then collecting the extra eggs she produces temporarily disrupts any IVF attempt conducted shortly afterwards.
The researchers said the results argue for more IVF cycles to be completed using frozen embryos, which goes against current practice. The most recently available UK figures show that, in 2006, 29,304 patients under 35 received IVF treatment cycles using fresh embryos, while 6,894 were treated with frozen cycles. The new data suggests this preponderance of fresh cycles puts IVF babies at higher risk of being born prematurely and underweight, or dying soon after birth.
The new data poses a dilemma for IVF clinics, because fresh cycles tend to be more successful at resulting in pregnancies - 31% of fresh cycles in 2006 for under 35s resulted in a birth, compared with 20.1% for frozen cycles.
"Frozen embryo transfers are not as successful as fresh ones in terms of getting a pregnancy. So it may be that we have to balance the health of children against chances of success," said Dr Allan Pacey from the University of Sheffield, who is secretary of the British Fertility Society.
"In a normal IVF cycle patients have their embryo transfer while the uterus is still affected by the drugs they take to stimulate the ovaries. This allows the patient's body to get rid of the drugs, and to grow a new endometrial lining," said Dr Mandy Katz-Jaffe, of the Colorado Centre for Reproductive Medicine.
In the Australian study a team lead by Prof Gordon Baker at the Royal Women's hospital in Melbourne analysed data from all Melbourne's fertility centres collected between 2001 and 2004. They found 469 (11%) of the 4,279 attempts using fresh embryos resulted in babies with a low birth weight (less than 2.5 kg), compared with 163 (6.5%) of the 2,510 IVF cycles using frozen embryos. Similarly, the fresh cycles had a higher proportion of babies dying within 28 days (1.87% to 1.16%) and more pre-term births (12.3% to 9.4%) - defining pre-term as earlier than 37 weeks.
"These results suggest that adverse birth outcomes of assisted reproductive therapy are associated with fresh embryo transfers," the authors wrote.
Using frozen embryos also has benefits for the mother. One risk posed by drugs used to stimulate the ovaries is a condition called ovarian hyperstimulation syndrome (OHSS), which can be fatal in rare cases. At present, if patients begin to develop symptoms, fertility doctors typically abandon an IVF attempt using fresh embryos because the hormonal disruption of pregnancy can make OHSS worse.
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01:09
It was one of the most memorable day's fishing of my life. I was 10 and my dad took me and my friend Charlie out on a charter boat from Looe in Cornwall. Shark fishing then was just taking off as a sport, and the main quarry was the small but fast blue shark. We all caught one and it was undeniably a thrill, hearing the line squealing off the reel. Mine was only 18kg (40lb), so didn't quite feel like a real shark, but my dad caught one twice that size - and taller than me.
Looking back, I've never felt that good about it. The sharks were killed and hung up from a kind of gibbet at the back of the boat, their guts hanging out of their mouths. Even then, my pride, and anticipation of a good bragging to my landlubber friends, were tempered by a creeping sense of shame.
I hope the sharks we caught somehow got eaten. I'd feel a little better to know that, in the days before anybody even considered the "ecological impact" of shark fishing, they were at least giving somebody a good meal. But I suspect they didn't. In some coastal parts of the world shark is a traditional part of the local fish diet. But pursuing them with modern fishing vessels can only lead to their rapid demise. Despite their astonishing success as a species - they've been around unchanged since the time of dinosaurs - they have a flaw in their otherwise perfect evolutionary design. Unlike most other fish, which produce vast numbers of eggs, and swim in huge shoals, sharks are just not meant to be hunted.
Rather, their place in nature is at the top of the food chain. That's why they are slow growers, who lay small numbers of eggs - or in some cases, such as the spurdog, give birth to live young. Start killing the adult breeding stock and numbers will soon crash to a tipping point. That's why extinction is a very real risk of commercially targeting certain species of shark.
Several species of small British shark are now in serious trouble - for decades the spurdog, tope and bull huss were collectively marketed in fishmongers and chip shops as "rock salmon". You won't see them much now, because there just aren't many left. The porbeagle, our largest native shark, is now also on the endangered list - it's the latest Atlantic species to be targeted to satisfy the insatiable demand for dried shark fins in the far east.
The only shark species that I could possibly condone eating is the smallest of all our sharks, which we call the lesser spotted dogfish. Its numbers are very high because it's a highly successful scavenger, and one member of the shark family that seems to be doing well in the face of overfishing.
Any small shark is likely to be labelled "huss" at the fishmonger. Once skinned and gutted, their long tapering bodies all look the same. If it's longer than about 18in or thicker than about 2in, then it's definitely not a dogfish. It must be some other kind of shark and you should leave well alone.
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01:06
It has become commonplace for people who are overweight to attribute their waistline to their DNA. Now, celebrities caught snorting cocaine might also be able to blame their parents.
Scientists reported yesterday the discovery of a gene that increases the chances of becoming hooked on the drug. Addicts were 25% more likely to carry the gene variant than people who did not use cocaine, a study found.
The discovery is unlikely to lead to a treatment for cocaine addicts, but scientists hope it could be used to screen for those most likely to have problems kicking the habit if they ever try the drug.
"If you are a carrier of this gene variant, the likelihood of getting addicted to cocaine is higher," said Rainer Spanagel, a professor of psychopharmacology at the Central Institute of Mental Health in Mannheim, Germany, who led the study. "You can certainly use this as a vulnerability marker for cocaine addiction."
He said people found to be susceptible to cocaine addiction could be given counselling or protected with experimental vaccines now being developed. The vaccines are designed to block the "high", or euphoria, associated with the drug.
Last week, an analysis by the European Union's drug agency put Britain at the top of its list of cocaine-abusing states, with its users outnumbering all those elsewhere on the continent.
Genetic factors, scientists believe, account for 70% of cocaine addiction, making it as heritable as schizophrenia and other mental health conditions. Studies of twins suggest alcoholism is about 50% genetic.
Researchers linked a version of the CAMK4 gene with cocaine addiction after studying mice that had been genetically modified to alter the gene. One particular breed was affected more strongly by the drug and became addicted quicker than others in the group, according to the study in the US journal, Proceedings of the National Academy of Sciences.
To see if the gene played a role in cocaine addiction in humans, the researchers ran genetic tests on 670 cocaine addicts and more than 700 matched non-users. While 40% of non-users carried the gene, it was found in half of the addicts.
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01:06Obituary: A leading biochemist known for his research into carotenoids
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01:05Alarming numbers of young people are now being treated in hospital for alcohol-related problems. Cherrill Hicks looks at the long-term implications
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MONDAY 10. NOVEMBER, 2008
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21:00
August 9 2001. This date is seared in the minds of many US scientists as the most potent symbol of the Bush administration's willingness to put religious-inspired ideology over rationalism and scientific progress.
This was president Bush's cut-off date for federal funding of embryonic stem cell research. Any cell lines created after this date could not benefit from federal funding including the massive $28bn pot handed out annually by the National Institutes of Health.
Sweeping away the policy looks like being an early priority for president-elect Obama and it was a cornerstone of his science manifesto (pdf).
This is an important step that will accelerate stem cell research in the US. Private and state funding has maintained America's position as the world leader in stem cell research, but the confidence of longer term federal funding for blue skies research will undoubtedly give the field a boost.
It will also leave other countries vulnerable to an exodus of talent as research opportunities in the US spring up. The UK in particular has benefited from Bush's restrictive policies with several talented US researchers choosing to base themselves there and doubtless many more UK scientists deciding not to make the trip across the pond.
The change can only help scientists' understanding of how human tissues develop and bring forward treatments for so far intractable diseases such as Alzheimer's and Parkinson's. But it won't change anything overnight. Research is a long game and it will be years or decades before this decision bears fruit.
More importantly, it sends an early message about how this administration values research, evidence and rational argument. Many in the scientific community have spent the last eight years fighting ideological obstructions to their work.
Public health researchers under Bush were stopped from attending conferences or promoting evidence for the effectiveness of condoms against the Aids pandemic; scientific advice on climate change was doctored by administration lackeys to play down the causal role human activities; and expert advisory committees were stacked with ideologues. Even the president's science adviser was kicked out of the White House to a place in the Washington bureaucracy where he could safely be ignored. Obama has pledged to restore the position's previous authority.
Repealing Bush's stem cell law is an easy and obvious change to make. Much more significant though will be whether Obama's administration brings sound scientific advice and a thoughtful rationalist approach back into the Oval Office. The consequences of that go way beyond US science.
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