Soy may benefit stroke patients

A chemical found in soybeans and chickpeas could benefit people who have suffered a stroke, say researchers.

The University of Hong Kong team say the treatment effect of the chemical, isoflavone, is comparable to that of cholesterol-busting statin drugs.

The European Heart Journal study showed isoflavone helped improve blood flow through the arteries.

Previous research has suggested that eating soy may help prevent breast and prostate cancer and lower cholesterol.

Protective effect

Soya isoflavones in particular have been shown to reduce cardiovascular disease risk as they inhibit the growth of cells that form artery-clogging plaque.

All of the 102 patients in the latest trial had suffered a first or recurrent ischaemic stroke -caused by a blood clot – in the previous six months and had established heart disease.

The patients were split into two groups, with one receiving a 12-week course of isoflavone as an 80mg daily dietary supplement, and the other given a dummy pill or placebo.

Diets with higher isoflavone contents might be beneficial in reducing cardiovascular risk in ischaemic stroke patients Lead researcher Professor Hung-Fat Tse

The scientists measured the way the brachial artery – the main artery of the arm – dilated in response to an increase in blood flow.

This measurement, the flow-mediated dilatation (FMD), is an indicator of the functioning of the cells that line the inner surfaces of blood vessels – the endothelium – which are implicated in cardiovascular disease.

At the start of the study the prevalence of impaired FMD was similar between the two groups.

But after 12 weeks, the FMD improved significantly in the patients given the isoflavone supplement.

High-soy diet

Lead researcher Professor Hung-Fat Tse said: “These findings suggest that isoflavone reverses endothelial dysfunction.”

He said there were important clinical implications, as the benefit of the treatment was conferred to the group of patients with the highest risks for cardiovascular events, and the effect persisted, even at a rather late stage of disease.

Professor Tse said it was too early to recommend the use of isoflavone supplements.

But he said: “Diets with higher isoflavone contents might be beneficial in reducing cardiovascular risk in ischaemic stroke patients.”

He said the mechanism by which isoflavone produces these changes in FMD were still not completely understood.

Isoflavone is a major class of phytoestrogens, naturally occurring chemicals that mimic the effect of the human hormone oestrogen. Oestrogen is known to protect against heart disease.

Dr Peter Coleman from The Stroke Association said: “This is an important and interesting study showing that dietary supplementation with isoflavones in people who have had a stroke may reduce their risk of further stroke or cardiovascular disease.

“Whilst this is a positive finding, it was a small study and further research is needed to discover how plant isoflavones could reduce stroke risk.”

 

Expert explores chemistry of love

Expert explores chemistry of love

Love can be put down to an increase in hormones, scientists say The science behind mother and baby bonding and sexual chemistry between partners is to be explained in a St Valentine’s Eve lecture. Edinburgh brain expert Professor Gareth Leng will examine how the hormone oxytocin helps forge permanent ties between lovers, after the initial rush of excitement of a new relationship. The hormone works by “changing the wiring” of billions of brain circuits. Prof Leng is a neuroscientist at the University of Edinburgh. Maternal behaviour He will provide a breakdown of the brain’s functions in relation to love during a lecture in London on Friday, 13 February entitled “How does a brain fall in love?” According to Prof Leng, oxytocin helps bond a mother and her baby and is also released during both childbirth and orgasm. He said it acts like a “master switch” in the brain, opening up new patterns of interaction between nerve cells. How a single, albeit prolonged, exposure to oxytocin can produce such profound and prolonged changes in behaviour is not known, but we are trying to find answers Prof Leng He also claims that people who have fewer of the special brain receptors needed to take up the oxytocin may have difficulties in making successful permanent bonds with their partners. Research has found that the hormone, which is released into the brain in large amounts during labour and during sexual activity, is an important trigger of maternal behaviour in animals. Its crucial role in sexual bonding has been observed by North American scientists studying the prairie vole. Professor Leng said: “The prairie vole mates for life and this life-long bond is established over the 48 hours of intense mating activity that is its first experience of sex. “During this time, large amounts of oxytocin are released within the brain. Prairie voles have oxytocin receptors in different parts of their brains, and scientists have found that blocking these receptors prevents the formation of pair-bonding in females. “How a single, albeit prolonged, exposure to oxytocin can produce such profound and prolonged changes in behaviour is not known, but we are trying to find answers. “Understanding this process is essential to understanding how drugs can influence mood and behaviour, for good or bad.”

Shopping urges ‘spotted in brain’

Shopping urges ‘spotted in brain’

Volunteers were scanned as they looked at desirable goods The moment when a shopper decides to buy can now be clearly seen on a brain scan, thanks to a US study.Volunteers were scanned as they looked at desirable goods and their prices, and the most active brain areas recorded. The results suggest different parts of the brain anticipate having the item, and feel the ‘pain’ of preparing to part with money. The Stanford University study was published in the Neuron journal. The experiment used an MRI scanner set up to detect brain activity. Deal or no deal Pictures of goods such as boxes of chocolates were shown, then a few seconds later, the price flashed up on the screen, before the volunteers were asked to decide whether or not to buy. The timing meant that the mental battle between desire for the object, and caution about spending, was clearly shown. This finding has implications for understanding behavioural anomalies, such as consumers’ growing tendency to overspend…when purchasing with credit cards Stanford University researchers If the volunteer wanted the product, a part of the brain called the nucleus accumbens lit up. Then, when the price appeared, a high price activated a part called the insula, and deactivated other parts. In this way, the researchers were able to predict the outcome. The researchers said the results clearly demonstrated the truth of the principle that purchasing is a mental ‘trade-off’ between the pleasure of acquisition and the pain of paying. Card trick They said that the study could reveal how credit cards ‘trick’ the brain into buying more. They wrote: “This finding has implications for understanding behavioural anomalies, such as consumers’ growing tendency to overspend and under save when purchasing with credit cards rather than cash.” Dr Alain Dagher, from the Montreal Neurological Institute, said that the brain mechanisms in action were evolved to suit more primitive uses. He said: “Human financial behaviour is often seemingly irrational, a fact that provides employment for advertisers, casino workers, insurance salesmen, and economists.” He said that it might be possible to understand more about compulsive shoppers and gamblers by spotting problems in the brain areas revealed by the scans.

Spinal fluid protein points to Alzheimer’s test

Spinal fluid protein points to Alzheimer’s test

Thursday, June 19, 2008

Content provided by Reuters

NEW YORK (Reuters Health) – Postmortem studies have identified an abnormal complex of two proteins in the spinal fluid of people with various degrees of cognitive impairment. Researchers say it could lead to a test for early Alzheimer’s disease.

Dr. Mark A. Lovell and colleagues at the University of Kentucky in Louisville measured levels of the complex, made up of an enzyme called prostaglandin-d-synthase and a protein called transthyretin, in autopsy samples from 7 normal people, 12 who had died of various diseases, 4 subjects with mild cognitive impairment and 8 individuals with late-stage Alzheimer’s disease.

As they report in the medical journal Neurology, the researchers found a significant increase in the complexes in the cerebrospinal fluid of the subjects with mild cognitive impairment and in those with late Alzheimer’s disease, but not in the others.

The team also measured levels of the complex in cerebrospinal fluid obtained by lumbar punctures in living individuals — 15 subjects with probable Alzheimer’s disease and 14 age-matched normal “controls.”

They investigators found six-fold higher levels in the probable Alzheimer’s subjects compared with the controls.

What gives rise to the formation of the abnormal protein complex is not known. Nonetheless, Lovell and colleagues say, measuring concentrations of the complex may “may allow identification of subjects with Alzheimer’s disease early in the disease … and could be developed as a useful diagnostic tool in the clinical setting.”

SOURCE: Neurology, online June 6, 2008.

Sexuality shown by thumbprints say scientists

Sexuality shown by thumbprints say scientists

First it was the so-called “gay gene” and now scientists say they have proof homosexuals have different fingerprints.

Chandler Burr, science journalist and gay man, speaking about the nature/nurture argument (1′ 23″)

Professor Richard Green, from London’s Charing Cross Hospital, says gay men have significantly fewer ridges on their right thumbs than heterosexual men.

The inference is that a gene, responsible at least in part, for shaping fingerprints also, somehow, has a role in determining sexual orientation.

The discovery, made after extensive comparisons of the prints of gay and “straight” men, is likely to reignite the age-old argument about whether sexual orientation is predestined or not.

It also raises the prospect of a genetic test for homosexuality and the question of whether parents, or society, should be allowed to take any action based on such information.

Science journalist Chandler Burr, himself a gay man, is the author of “A Separate Creation: How Biology Makes Us Gay”.

He says the study provides further ammunition to those, like him, who claim sexual orientation is predestined at birth.

Mr Burr says it is clear homosexuality is an inborn instinct and not a “frivolous lifestyle” which was chosen at whim.

He says not all people with gay orientations choose to “come out” and some stay in their “closets” all their lives.

Anya Palmer, of the gay and lesbian rights group Stonewall, comments on the research (21″)

Anya Palmer, from the gay and lesbian rights group Stonewall, says the question of whether an individual’s homosexuality is innate or imported is irrelevant.

She says it is more important to make sure all homosexuals’ human rights are protected.

 

Womb environment ‘makes men gay’

Womb environment ‘makes men gay’

Scientists think antibodies produced in the womb may be responsible A man’s sexual orientation may be determined by conditions in the womb, according to a study.Previous research had revealed the more older brothers a boy has, the more likely he is to be gay, but the reason for this phenomenon was unknown. But a Canadian study has shown that the effect is most likely due to biological rather than social factors. The research is published in the journal of the Proceedings of the National Academy of Sciences. Professor Anthony Bogaert from Brock University in Ontario, Canada, studied 944 heterosexual and homosexual men with either “biological” brothers, in this case those who share the same mother, or “non-biological” brothers, that is, adopted, step or half siblings. These results support a prenatal origin to sexual orientation development in men Professor Anthony Bogaert He found the link between the number of older brothers and homosexuality only existed when the siblings shared the same mother. The amount of time the individual spent being raised with older brothers did not affect their sexual orientation. ‘Maternal memory’ Writing in the journal, Professor Bogaert said: “If rearing or social factors associated with older male siblings underlies the fraternal birth-order effect [the link between the number of older brothers and male homosexuality], then the number of non-biological older brothers should predict men’s sexual orientation, but they do not. “These results support a prenatal origin to sexual orientation development in men.” He suggests the effect is probably the result of a “maternal memory” in the womb for male births. A woman’s body may see a male foetus as “foreign”, he says, prompting an immune reaction which may grow progressively stronger with each male child. The antibodies created may affect the developing male brain. In an accompanying article, scientists from Michigan State University said: “These data strengthen the notion that the common denominator between biological brothers, the mother, provides a prenatal environment that fosters homosexuality in her younger sons.” “But the question of mechanism remains.” Andy Forrest, a spokesman for gay rights group Stonewall, commenting on this and other studies, said: “Increasingly, credible evidence appears to indicate that being gay is genetically determined rather than being a so-called lifestyle choice. “It adds further weight to the argument that lesbian and gay people should be treated equally in society and not discriminated against for something that’s just as inherent as skin colour.”

Scans see ‘gay brain differences’

Scans see ‘gay brain differences’

The study suggests sexual orientation may be set in the womb The brains of gay men and women look like those found in heterosexual people of the opposite sex, research suggests. The Swedish study, published in the Proceedings of the National Academy of Sciences journal, compared the size of the brain’s halves in 90 adults. Gay men and heterosexual women had halves of a similar size, while the right side was bigger in lesbian women and heterosexual men. A UK scientist said this was evidence sexual orientation was set in the womb. As far as I’m concerned there is no argument any more – if you are gay, you are born gay Dr Qazi Rahman Queen Mary, University of London Scientists have noticed for some time that homosexual people of both sexes have differences in certain cognitive abilities, suggesting there may be subtle differences in their brain structure. This is the first time, however, that scientists have used brain scanners to try to look for the source of those differences. A group of 90 healthy gay and heterosexual adults, men and women, were scanned by the Karolinska Institute scientists to measure the volume of both sides, or hemispheres, of their brain. When these results were collected, it was found that lesbians and heterosexual men shared a particular “asymmetry” in their hemisphere size, while heterosexual women and gay men had no difference between the size of the different halves of their brain. In other words, structurally, at least, the brains of gay men were more like heterosexual women, and gay women more like heterosexual men. A further experiment found that in one particular area of the brain, the amygdala, there were other significant differences. In heterosexual men and gay women, there were more nerve “connections” in the right side of the amygdala, compared with the left. The reverse, with more neural connections in the left amygdala, was the case in homosexual men and heterosexual women. The Karolinska team said that these differences could not be mainly explained by “learned” effects, but needed another mechanism to set them, either before or after birth. ‘Fight, flight or mate’ Dr Qazi Rahman, a lecturer in cognitive biology at Queen Mary, University of London, said that he believed that these brain differences were laid down early in foetal development. “As far as I’m concerned there is no argument any more – if you are gay, you are born gay,” he said. The amygdala, he said, was important because of its role in “orientating”, or directing, the rest of the brain in response to an emotional stimulus – be it during the “fight or flight” response, or the presence of a potential mate. “In other words, the brain network which determines what sexual orientation actually ‘orients’ towards is similar between gay men and straight women, and between gay women and straight men. “This makes sense given that gay men have a sexual preference which is like that of women in general, that is, preferring men, and vice versa for lesbian women.”

What do you remember?

What do you remember?

Eyewitnesses were badly wrong about the shooting of Jean Charles de Menezes By Rebecca Fordham If someone was killed in front of you would you remember what happened? Many experts are challenging the view that eyewitnesses recounting what they saw is the best way of tapping their memory. Some think brain scans could be the way forward. Think of a journey you made yesterday. I’m sure you remember it. So can you remember whom you sat next to? Can you remember what the weather was like? Who was in front of you in the petrol queue? Was it a man or a woman? FIND OUT MORE… Law in Action is on Radio 4 on Tuesday, 1600 BST Or catch up at Radio 4’s Listen Again site Naturally, most of the time we don’t remember these details. But what if someone got knifed in the petrol station? Then we become witnesses to a crime. And our ability to recall these minor details may have a significant role in authenticating our memory of the offence. Some researchers suggest that we shouldn’t need to remember these details. They are increasingly questioning the way that the police, lawyers and the courts think about memory. They argue that this conventional model of memory – like a detailed photograph or video film – is fundamentally flawed. One of the most prominent of these researchers, Prof Elizabeth Loftus of the University of California at Irvine, even says that courts should have a new oath for witnesses: “Do you swear to tell the truth, the whole truth, or whatever it is you think you remember?” Memory research Now Prof Martin Conway, a cognitive psychologist at Leeds University, has drawn up a report for the British Psychological Society and the Law Society calling for a major rethink of memory and the law. He suggests his guidelines will help scientists who specialise in memory research when they testify as expert witnesses to help the courts assess the evidence. Neuroimaging could offer a way forward in court Memories are essentially a construct from a variety of sources and experiences, Prof Conway says. They are not necessarily a factual account of what happened. What’s more, a significant proportion of people seem to be highly suggestible and will quite readily change what they remember if given appropriate cues. In one famous study, Dutch researchers questioned people about a 1992 accident in which a cargo plane had crashed into a block of flats near Schiphol Airport. Ten months later, they conducted a survey asking if people remembered seeing the TV film of the plane hitting the building. More than half of the respondents said they had. A later study found that the proportion had gone up to two-thirds. The problem is, there is no TV film of the accident. Asking the question had itself apparently changed people’s memories. A similar phenomenon happened with the shooting in London of the suspected terrorist Jean Charles de Menezes at Stockwell Underground Station. EYEWITNESS ERRORS Jean Charles de Menezes: Eyewitnesses claimed to have seen bulky jacket, victim jumping barriers – not correct Jennifer Thompson: US rape victim identified wrong man with absolute certainty – suspect exonerated by DNA evidence Initially witnesses claimed that he was wearing bulky clothing and that he had vaulted the ticket barriers as he ran from police. A police spokesman said on the day that, “his clothing and behaviour added to their suspicions”, and that he ran onto the train after police had issued warnings. These claims were incorrect. But people still express surprise when told he wasn’t wearing a large coat and are confused about how he entered the tube because the inaccurate reports became cemented into individual memories. So are witnesses consciously or subconsciously having their memories altered? There is little data available regarding the extent of suggestive questioning of eyewitnesses. One British study using actual interviews indicates that approximately one out of every six questions posed to eyewitnesses was in some way suggestive. The police say they are already aware of the risks and do their utmost to avoid them. Doubtful memory At Hendon Police Training College, in north London, one of the courses trains officers in interviewing eye witnesses. The officers are shown a video of a dramatised murder and then questioned by a colleague. One half-remembered a northern accent. When questioned further, she said she thought the accent was Mancunian but she couldn’t be sure. The interviewer pressed the would-be witness on the detail despite the original uncertainty. Our faculties are often impaired by the nature of the scene we are witnessing Prof Conway argues this sort of detail can mislead and that the interviewing process could turn a doubtful memory into fact. One technology that could help in future is brain scanning. Neuroimaging has now been developed in which objects unique to a crime scene are shown to witnesses, such as a lampshade or a particular colour. These would only be recognised if the person had been there. Witnesses’ brains are monitored to see if areas associated with memory light up when they see the objects. But it will be many years before such evidence is admissible in court. And many involved in the criminal justice system argue that the courts already have a good record of separating reliable and unreliable memories. Former judge Gerald Butler QC says jurors can use their commonsense to decipher the evidence and he is wary about introducing a new set of experts into the process. “I have had a long term concern about the evidence of experts,” he says. “I have heard so many experts giving evidence one way and then another expert giving evidence the other way. It’s very difficult to judge the expert and know which one is right and which one is wrong.”

More deaths for Caesarean babies

More deaths for Caesarean babies

Labour appears to help prepare the baby for life outside the womb Babies born by Caesarean are nearly three times more likely to die in the first month than those born naturally, US research shows. The findings, based on over 5.7 million births, are particularly important given the growing trend of women opting for Caesareans, say the authors. More than one in five of all British babies are now born by Caesarean. The Birth journal study included women with no obvious medical risks who had elected to have a Caesarean. Higher risk Even after adjusting the results for social and medical differences among the women, babies born by caesarean were still at more than twice the risk of dying in the first month of life. From 1998 to 2001, the death rate among those delivered by Caesarean was 1.77 per 1,000 live births compared to 0.62 for vaginal deliveries. This is a relatively small risk but it is there and people need to know that Professor James Walker of the Royal College of Obstetricians and Gynaecologists Generally, neonatal deaths are rare for low-risk women, in the order of one death per 1,000 live births, according to the lead researcher Dr Marian MacDorman of the Centers for Disease Control and Prevention. However, the study only include babies that were born alive, which the researchers said would change the results. Had stillbirths been included, the risk of vaginal deliveries would have been closer to that of Caesarean deliveries. Also, the deliveries in the study ranged from 37 weeks’ gestation to full-term or 41 weeks. In the UK, planned Caesarean sections are performed after 39 weeks’ gestation because it is known that deliveries earlier than this carry a higher risk to the baby. And the risks of both types of delivery are still extremely small. Explanation The researchers suggest that the process of labour helps prepare the baby for life outside of the womb. As well as squeezing fluid out of the lungs, it may promote the release of hormones that encourage healthy lung function. Dr MacDormac said: “Labour is an important part of the birthing process because it gets infants ready to breathe air and function outside the womb.” Professor James Walker, consultant obstetrician at St James’s University Hospital in Leeds and spokesman for the Royal College of Obstetricians and Gynaecologists, said women should not be alarmed by the findings but should be informed. “The absolute risk is still very small. “But it should open people up to the fact that there are risks and benefits of everything. This is a relatively small risk but it is there and people need to know that.” Belinda Phipps of the National Childbirth Trust said: “I think that the study does need to be taken pretty seriously.” She said that earlier studies had already hinted that babies born by Caesarean are more likely to experience breathing problems.

Caesarean ‘raises womb-tear risk’

Caesarean ‘raises womb-tear risk’

Around a third of women try for a vaginal birth after a Caesarean A Caesarean section increases the risk by 50-fold that a woman’s uterus will rupture during a subsequent vaginal delivery, research suggests.A torn uterus can put the life of both the mother and baby in danger. US and Swedish researchers found the condition afflicted nine in every 1,000 mothers who opted to try for a vaginal birth after a previous Caesarean. In contrast, the BJOG study found the rate among women with no history of a Caesarean was just 0.18 per 1,000. Although uterine rupture is a relatively rare occurrence, the consequences can be devastating Professor Philip Steer BJOG editor-in-chief Many women who have previously had a Caesarean are offered the option of another, planned Caesarean second time around. However, around a third of women opt to try for a vaginal birth to avoid what is a major operation which carries risk both for the mother and baby. The findings were based on a study of more than 300,000 Swedish women by Emory University, Atlanta, and the Karolinska Institute in Stockholm. Fourteen of the 274 women who suffered a torn uterus lost their baby – a death rate of 51 per 1,000. In contrast, the neonatal death rate among women who did not develop the condition was just 1.4 per 1,000. Other risk factors A prior Caesarean section was not the only factor which increased risk. Women who gave birth aged 35 or older were nearly three times more vulnerable to a uterine tear than women aged 24 or younger. Clinically obese women had more than twice the risk of women who were not overweight. And inducing labour appeared to double the risk, compared to labour which began spontaneously. The researchers suggested the chemicals used to induce birth weakened previous Caesarean scars, making them more likely to rip. Women who gave birth late were discovered to be more at risk than those who gave birth after a normal-length pregnancy, regardless of whether they had had a Caesarean section before. And women who gave birth to babies weighing at least 4kg were at twice the risk than women whose babies were less than 4kg. Researcher Dr Melissa Kaczmarczyk, of Emory University, said it was important that patients were made fully aware of the risks, and that those at higher risk were carefully managed through labour. Professor Philip Steer, BJOG editor-in-chief, said: “The rate of Caesarean deliveries continues to increase in the developed world which means that a growing percentage of women will experience birth following a previous Caesarean section. “Although uterine rupture is a relatively rare occurrence, the consequences can be devastating. “The link between a prior Caesarean section and uterine rupture during subsequent delivery warrants very careful management of pregnancy and labour so that early signs of difficulty can be speedily detected.” Mervi Jokinen, of the Royal College of Midwives, said the study highlighted the fact that a Caesarean carried a long-term risk to health. “We believe the Caesarean rate should be between 10% and 15%, but at present it is 23% in the UK,” she said. “We should be asking ourselves why the Caesarean rate is so high.”