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2010 Sep 11

شنبه 20 شهريور 1389

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2010-5-6

New hope for HIV vaccine efforts
They believe rare individuals who progress very slowly to Aids when infected make white blood cells that are better at fighting the virus. The findings, published in Nature, may help international efforts to design an effective Aids vaccine. But the research team at MIT and Harvard says any such vaccine is at least a decade away. The findings relate to so-called "elite controllers" - a small number of people who, when exposed to HIV, progress very slowly to Aids or never develop it at all.In the late 1990s it was discovered that these individuals - about one in 200 of those infected with HIV - carry a specific gene, known as HLA B57. The research team, led by MIT Professor Arup Chakraborty and Harvard Professor Bruce Walker, found this gene causes the body to make more potent killer T cells - a type of white blood cell that fights infections. This helps them to keep the HIV virus at bay, but also makes them more susceptible to autoimmune diseases, where the body's immune system turns on itself. The work is based on computer modelling of how immune cells develop in a specialised organ of the immune system known as the thymus.

2010-4-19

Well-done meat doubles bladder cancer risk
Frying, grilling and barbecuing until meat is charred can form cancer-causing chemicals, research shows. In a study, people whose diets included well-done meats were over twice as likely to develop bladder cancer than those who preferred meats rare. The research findings, based on over 1,700, people were presented at a US cancer research conference. The University of Texas investigators found the risk was highest for those who ate well-done red meat such as steaks, pork chops and bacon.But even chicken and fish, when fried, significantly raised the odds of cancer. Three major types of the cancer-causing chemicals, collectively called heterocyclic amines (HCAs), raised cancer risk by more than two-and-a-half. And some people appear to be genetically more susceptible to this diet-linked cancer risk, the researchers found. In the study, which took place over 12 years, the researchers analysed the DNA of all the participants to look for any differences in the way individuals metabolised the cooked meat. Having particular genes made some people almost five times as likely to develop bladder cancer when they ate a lot of red meat. Lead author of the study, Professor Xifeng Wu, told the American Association for Cancer Research: "This research reinforces the relationship between diet and cancer. "These results strongly support what we suspected - people who eat a lot of red meat, particularly well-done red meat, such as fried or barbecued, seem to have a higher likelihood of bladder cancer." According to the National Cancer Institute in the US, experts have identified 17 different HCAs that "may pose human cancer risk". Charred meat has already been linked to pancreatic cancer. Cancer experts said that more research was needed before we can say for sure whether or not regularly eating red meat affects bladder cancer risk, and if the way it is cooked has an impact.

2010-4-14

Aspirin can reduce migraine symptom pain, review says
The results come from a Cochrane Systematic Review using data from 13 studies. Researchers found that a high dose of aspirin also reduces nausea, vomiting and sensitivity to light or sound - other symptoms of a migraine. But experts stress aspirin can cause side effects and some people will still need to rely on migraine medication. In the review, which looked at the data from 4,222 participants, researchers found that severe or moderate migraine headache pain was completely relieved in one in four people. This happens within two hours, by taking a single dose of 900-1,000mg aspirin alone (a standard tablet is 300mg). In comparison, one in 10 had complete pain relief taking placebo. And for one in two people, the headache pain was reduced to no worse than mild pain, compared to one in three taking placebo. Researchers also found that a combination of aspirin plus an anti-emetic, which stops people feeling sick, was particularly good at reducing the migraine symptoms of nausea and vomiting. However, it did not produce any greater pain relief. Co-author of the study, Sheena Derry, who works in pain research at the John Radcliffe Hospital in Oxford, said the use of aspirin would not be an effective therapy for everyone with acute migraine attacks. "This is largely down to genetic differences," she said. "Different people respond to different drugs in different ways, and at different times." Researchers say that further studies are needed to establish the effectiveness of aspirin compared with other drugs.

2010-4-7

Five-a-day has little impact on cancer, study finds
The study of 500,000 Europeans joins a growing body of evidence undermining the high hopes that pushing "five-a-day" might slash Western cancer rates.The international team of researchers estimates only around 2.5% of cancers could be averted by increasing intake. But experts stress eating fruit and vegetables is still key to good health. In 1990, the World Health Organization recommended that everyone consume at least five portions of fruit and vegetables a day to prevent cancer and other chronic diseases. The advice has formed a central plank of public health campaigns in many developed countries. It has been promoted in the UK since 2003 and in the US for nearly two decades. But research has failed to substantiate the suggestion that as many as 50% of cancers could be prevented by boosting the public's consumption of fruit and vegetables. This latest study, which analysed recruits from 10 countries to the highly-regarded European Prospective Investigation into Cancer and Nutrition, confirms that the association between fruit and vegetable intake and reduced cancer risk is indeed weak. The team, led by researchers from the Mount Sinai School of Medicine, in New York, took into account lifestyle factors such as smoking and exercise when drawing their conclusions. But writing in the Journal of the National Cancer Institute, they said they could not rule out that even the small reduction in cancer risk seen was down to the fact that the kind of people who ate more fruit and vegetables lived healthier lives in many other respects too.

2010-3-30

Chocolate 'can cut blood pressure and help heart'
The study of over 19,000 people, published in the European Heart Journal, found those who ate half a bar a week had lower blood pressure. They also had a 39% lower risk of heart attacks and strokes. Heart campaigners warned that too much chocolate is damaging because is has a lot of calories and saturated fat. The study looked at the chocolate consumption of middle-aged men and women over eight years. It compared the health of those who ate the most and least chocolate.The difference between these two groups was just 6 grams a day, equivalent to one small square of chocolate a day. The lead author, Dr Brian Buijsse, from the German Institute of Human Nutrition, Nuthetal said: "Our hypothesis was that because chocolate appears to have a pronounced effect on blood pressure, therefore chocolate consumption would lower the risk of strokes and heart attacks, with a stronger effect being seen for stroke." This is, in fact, what the study found. Those who ate more chocolate cut their risk of heart attacks by around a quarter, and of stroke by nearly half, compared with those who ate the least.

2010-3-24

X-rays 'can miss many fractures', warn doctors
X-rays fail to spot up to nearly a third of fractures in the bones of the hip and pelvis, research suggests.US doctors from Duke University warn that relying on standard X-rays alone to give a clean bill of health could lead to wrong diagnoses and law suits. When they re-checked the X-ray results of 92 patients using a more detailed scanner, called MRI, they found 35 fractures that had been missed. The findings are published in the American Journal of Roentgenology. Dr Charles Spritzer, who led the research, said: "The diagnosis of traumatic fracture most often begins and ends with X-rays of the hip, pelvis, or both. "In some cases though, the exclusion of a traumatic fracture is difficult."

2010-3-14

Gum disease 'linked to early births'
Successful treatment for gum disease cuts the risk of pregnant women giving birth early, US research suggests.The preliminary research showed those whose gum disease was not treated successfully were three times more likely to give birth before 35 weeks. The study of 160 women was presented to the annual conference of the American Association for Dental Research. UK experts said the finding was "controversial" but advised pregnant women to take care of teeth and gums. Doctors have previously established that severe gum infections cause an increase in the production of prostaglandin and tumour necrosis factor, chemicals which induce labour, to be produced. The study by researchers at the University of Pennsylvania enrolled women who were between six and 20 weeks' pregnant.All of the volunteers had gum disease. These women were given treatment, which was successful in one third of the cases. The researchers found a "strong and significant association" between successful treatment and full-term births. Those whose treatment did not work were "significantly more likely" to give birth before 35 weeks.

2010-3-10

'No evidence' acupuncture boosts chances of IVF baby
There is no evidence acupuncture or Chinese herbal medicine increase the chance of getting pregnant through IVF, fertility experts say in new guidance.The methods are increasingly offered as a way of boosting the chances of a baby, but the British Fertility Society suggests couples may be wasting money. They analysed 14 trials involving 2,670 people before issuing the new guidance. But a leading practitioner said that better designed trials would show that the methods could help some couples. All the trials involved acupuncture, in which needles were inserted into different areas of the body at different stages in the in vitro fertilisation (IVF) cycle. No matter at what stage of the process acupuncture was used, it had no impact on the pregnancy or live birth rate, the BFS researchers found. They did however also find it caused no harm, with no difference in miscarriage rates. There were no published trials on the use of Chinese herbs which were rigorous enough for inclusion, so the team concluded that there was "currently no evidence to support the use of this in fertility treatments". As more couples seek IVF, there has been a growth in accompanying complementary therapies, and acupuncture has benefited. It is the most popular option for patients because it is thought to improve blood flow and increase the chance of an embryo implanting.

2010-3-4

UN warns HIV/Aids leading cause of death in women
HIV has become the leading cause of death and disease among women of reproductive age worldwide, the UN programme on HIV/Aids says.At the start of a 10-day conference in New York, UNAids launched a five-year action plan addressing the gender issues which put women at risk. One of the key issues, it says, is that up to 70% of women worldwide have been forced to have unprotected sex. UNAids says such violence against women must not be tolerated. "By robbing them of their dignity, we are losing the opportunity to tap half the potential of mankind to achieve the Millennium Development Goals," said Executive Director Michel Sidibe. "Women and girls are not victims, they are the driving force that brings about social transformation," he said. The agency says that experiencing violence hampers women's ability to negotiate safe sex. It warns that, nearly 30 years from the beginning of the epidemic, HIV services do not respond to the specific needs of women and girls. Women, it says, continue to be disproportionately affected by HIV/Aids. In sub-Saharan Africa, 60% of those living with HIV are women and in Southern Africa, for example, young women are about three times as likely to be infected with HIV than young men of the same age.

2010-3-3

'Heart risk' at football stadiums
Too many football grounds in Europe do not have the right equipment and plans to save the lives of fans who have heart attacks, a study has found.The poll of 187 stadiums found over a quarter did not have defibrillators and many did not have emergency plans. The Sweden-led study, carried out by a group of club doctors, stressed more had to be done as it was not always easy to get ill fans to hospital. Researchers said there should be mandatory rules covering the issue. At the moment, it is simply considered good practice to have defibrillators at sports grounds. But in recent years many governments - including the authorities in the UK - have been doing more to increase the availability of the life-saving equipment in public spaces. Defibrillators work by delivering a controlled electric shock through the chest wall to the heart to restore a normal heartbeat.

2010-2-22

Singing 'rewires' damaged brain
By singing, patients use a different area of the brain from the area involved in speech. If a person's "speech centre" is damaged by a stroke, they can learn to use their "singing centre" instead. Researchers presented these findings at the annual meeting of the American Association for the Advancement of Science (AAAS) in San Diego. An ongoing clinical trial, they said, has shown how the brain responds to this "melodic intonation therapy". Gottfried Schlaug, a neurology professor at Beth Israel Deaconess Medical Center and Harvard Medical School in Boston, US, led the trial.The therapy is already established as a medical technique. Researchers first used it when it was discovered that stroke patients with brain damage that left them unable to speak were still able to sing. Professor Schlaug explained that his was the first study to combine this therapy with brain imaging - "to show what is actually going on in the brain" as patients learn to sing their words.

2010-2-17

Acupuncture could help period pain, researchers say
Researchers said there was "promising evidence" for acupuncture in treating cramps, but that more work was needed. In the British Journal of Obstetrics and Gynaecology, they noted two studies found little difference between real and sham acupuncture in treating pain. Acupuncture is a less contentious form of complementary medicine than some, but its value is still disputed. Period pain can be severe in some women and may be accompanied by nausea, diarrhoea, migraine and backache. Common treatments include pain killers, applying heat and exercise - although a recent study questioned the efficacy of the latter. This latest review involved 27 studies - which included nearly 3,000 women. They addressed a variety of forms of acupuncture - from classical to acupoint injection. Traditional acupuncturists insert needles in acupuncture points located along what they describe as "energy meridians" - a concept for which many scientists say there is no evidence. Sham acupuncture places needles away from these points. It is not clear whether either form alleviates pain as a result of the placebo effect - the very ritual of undergoing acupuncture - or cause subtle changes in the nervous system and brain activity which can be beneficial.

2010-2-3

Fish oil supplements 'beat psychotic mental illness'
Taking a daily fish oil capsule can stave off mental illness in those at highest risk, trial findings suggest.A three-month course of the supplement appeared to be as effective as drugs, cutting the rate of psychotic illness like schizophrenia by a quarter. The researchers believe it is the omega-3 in fish oil - already hailed for promoting healthy hearts - that has beneficial effects in the brain. A "natural" remedy would be welcomed, Archives of General Psychiatry says. "The finding that treatment with a natural substance may prevent, or at least delay, the onset of psychotic disorder gives hope that there may be alternatives to antipsychotic drugs," the study authors said. Antipsychotic drugs are potent and can have serious side effects, which puts some people off taking them. Fish oil supplements, on the other hand, are generally well tolerated and easy to take, say the scientists. The international team from Austria, Australia and Switzerland tested the treatment in 81 people deemed to be at particularly high risk of developing psychosis.

2010-1-26

Prions 'may keep nerves healthy'
Experiments on mice may help scientists understand the workings of the prion protein linked to brain disease vCJD.Swiss researchers say there is evidence that prions play a vital role in the maintenance of the sheath surrounding our nerves. They say it is possible that an absence of prions causes diseases of the peripheral nervous system. One expert said there was growing evidence that the prion had a number of important roles in the body. As well as the latest research in the journal Nature Neuroscience, other studies have indicated prions may protect us from Alzheimer's disease or even play a role in our sense of smell.The prion protein only came to the attention of scientists in recent years as they searched for the cause of vCJD - the human variant of BSE, or Mad Cow Disease. This degenerative and incurable brain condition is now thought to be caused by a "mis-folded" version of the prion. However, there is still little understanding of what the protein is supposed to do in its normal, healthy, form.

2010-1-18

Weaker wine 'may lower the risk of some cancers'
Studies suggest that people who drink wine with an alcohol content of 10% rather than 14% might benefit, says the World Cancer Research Fund. The charity called for more low-alcohol wines and beers to be available for sale. An industry expert said UK consumers were asking for "lighter" wines. The calculation was based on figures in a 2007 report which looked at the evidence for a link between alcohol consumption and cancer. That report recommended that men should have no more than two drinks a day, and women no more than one. The figures used to reach that conclusion were detailed enough to reveal the likely extra risk posed by each extra 10 grams of alcohol - just over one unit - regularly consumed. From this, scientists calculated that, in theory, a person drinking one large 250ml glass of wine a night would have a 7% lower risk of bowel cancer if they normally drank 10% strength wine rather than 14%. From a cancer prevention point of view it is best not to drink at all. But we have to be realistic and the fact is that many people in the UK enjoy a drink and see it as part of their social life. This is only a modest decrease of risk for an individual, and there is no clear evidence about how long someone would need to substitute weaker wine for their usual tipple in order to reap this benefit. However, the charity said that for every 100 people who did it, one case of bowel cancer would be avoided. While the detailed studies only applied to bowel cancer, it said that there was no reason to believe that the risk of other cancers linked to alcohol, such as throat, oesophageal and breast, would not respond in a similar way.

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