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Friday, July 15, 2011

Scientists Discover New Role for Vitamin C in the Eye and the Brain

ScienceDaily

Friday, July 15, 2011

ScienceDaily (July 15, 2011) — Nerve cells in the eye require vitamin C in order to function properly -- a surprising discovery that may mean vitamin C is required elsewhere in the brain for its proper functioning, according to a study by scientists at Oregon Health & Science University recently published in the Journal of Neuroscience.

"We found that cells in the retina need to be 'bathed' in relatively high doses of vitamin C, inside and out, to function properly," said Henrique von Gersdorff, Ph.D., a senior scientist at OHSU's Vollum Institute and a co-author of the study. "Because the retina is part of the central nervous system, this suggests there's likely an important role for vitamin C throughout our brains, to a degree we had not realized before."

The brain has special receptors, called GABA-type receptors, that help modulate the rapid communication between cells in the brain. GABA receptors in the brain act as an inhibitory "brake" on excitatory neurons in the brain. The OHSU researchers found that these GABA-type receptors in the retinal cells stopped functioning properly when vitamin C was removed.

Because retinal cells are a kind of very accessible brain cell, it's likely that GABA receptors elsewhere in the brain also require vitamin C to function properly, von Gersdorff said. And because vitamin C is a major natural antioxidant, it may be that it essentially 'preserves' the receptors and cells from premature breakdown, von Gersdorff said.

The function of vitamin C in the brain is not well understood. In fact, when the human body is deprived of vitamin C, the vitamin stays in the brain longer than anyplace else in the body. "Perhaps the brain is the last place you want to lose vitamin C," von Gersdorff said. The findings also may offer a clue as to why scurvy -- which results from a severe lack of vitamin C -- acts the way it does, von Gersdorff said. One of the common symptoms of scurvy is depression, and that may come from the lack of vitamin C in the brain.

The findings could have implications for other diseases, like glaucoma and epilepsy. Both conditions are caused by the dysfunction of nerve cells in the retina and brain that become over excited in part because GABA receptors may not be functioning properly.

"For example, maybe a vitamin C-rich diet could be neuroprotective for the retina -- for people who are especially prone to glaucoma," von Gersdorff said. "This is speculative and there is much to learn. But this research provides some important insights and will lead to the generation of new hypotheses and potential treatment strategies."

Scientists and students in von Gerdorff's lab in OHSU's Vollum Institute are dedicated to basic neuroscience research. The vitamin C research work was done using goldfish retinas, which have the same overall biological structure as human retinas.

The retina research work was done by Ph.D. student Evan Vickers, working as part of the von Gersdorff lab. The work was in collaboration with Cecilia Calero in the lab of Dr. Daniel J. Calvo from the University of Buenos Aires, Argentina, and Gustavo Cid and Luis Aguayo from the University of Concepcion, Chile.

The work was funded by the Consejo Nacional de Investigaciones Científicas y Tecnicas (Argentina), the Pew Foundation, the International Brain Research Organization and the National Eye Institute of the National Institutes of Health.

The study was published online in the June 29 issue of the Journal of Neuroscience, which is the official journal of the Society for Neuroscience.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Oregon Health & Science University.

Journal Reference:

S. Cho, G.-L. Li, H. von Gersdorff. Recovery from Short-Term Depression and Facilitation Is Ultrafast and Ca2 Dependent at Auditory Hair Cell Synapses. Journal of Neuroscience, 2011; 31 (15): 5682 DOI: 10.1523/JNEUROSCI.5453-10.2011

Alcohol Affects Left, Right Heart Chambers Differently

HealthDay News

Friday, July 15, 2011

FRIDAY, July 15 (HealthDay News) -- The left and right ventricles of the heart have very different reactions to small amounts of alcohol, a new study finds.

Researchers in Italy examined 64 healthy volunteers in their 20s after they drank a small amount of red wine and an equal amount of fruit juice.

After drinking the wine, participants' left ventricular function decreased, according to the findings. The left ventricle receives oxygen-rich blood from the left atrium of the heart and pumps it into the aorta, or the main artery of the body, which supplies tissues with oxygen.

But in the right ventricle, the wine led to an increase in function. The right ventricle pumps blood to the lungs through the pulmonary arteries, so it can be refreshed with oxygen again before going to the left ventricle.

The two chambers of the heart "are like two different worlds," said corresponding author Matteo Cameli, a cardiologist at Italy's Cardiologia Universitaria of Siena, in a university news release.

"Little data exist regarding the acute effects of alcohol on the heart," Cameli said. "Previous studies have reported a reduction in [left ventricular] performance after an assumption of moderate or high doses of alcohol, but the effects of low doses are still unknown."

The possible toxic effects of low doses of alcohol on the heart are important given that light drinking is so common, he added.

The study's findings will be published in the October 2011 issue of Alcoholism: Clinical & Experimental Research.

More information

The American Heart Association provides more information on alcohol and heart disease.

Natural Chemical Found in Grapes May Protect Against Alzheimer's Disease

ScienceDaily

Friday, July 15, 2011

ScienceDaily (July 15, 2011) — Researchers at Mount Sinai School of Medicine have found that grape seed polyphenols -- a natural antioxidant -- may help prevent the development or delay the progression of Alzheimer's disease.

The research, led by Giulio Maria Pasinetti, MD, PhD, The Saunder Family Professor in Neurology, and Professor of Psychiatry and Geriatrics and Adult Development at Mount Sinai School of Medicine, was published online in the current issue of the Journal of Alzheimer's Disease.

This is the first study to evaluate the ability of grape-derived polyphenols to prevent the generation of a specific form of β-amyloid () peptide, a substance in the brain long known to cause the neurotoxicity associated with Alzheimer disease. In partnership with a team at the University of Minnesota led by Karen Hsiao Ashe, MD, PhD, Dr. Pasinetti and his collaborators administered grape seed polyphenolic extracts to mice genetically determined to develop memory deficits and neurotoxins similar to those found in Alzheimer's disease. They found that the brain content of the *56, a specific form of previously implicated in the promotion of Alzheimer's disease memory loss, was substantially reduced after treatment.

Previous studies suggest that increased consumption of grape-derived polyphenols, whose content, for example, is very high in red wine, may protect against cognitive decline in Alzheimer's. This new finding, showing a selective decrease in the neurotoxin *56 following grape-derived polyphenols treatment, corroborates those theories.

"Since naturally occurring polyphenols are also generally commercially available as nutritional supplements and have negligible adverse events even after prolonged periods of treatment, this new finding holds significant promise as a preventive method or treatment, and is being tested in translational studies in Alzheimer's disease patients," said Dr. Pasinetti.

The study authors emphasize that in order for grape-derived polyphenols to be effective, scientists need to identify a biomarker of disease that would pinpoint who is at high risk to develop Alzheimer's disease.

"It will be critical to identify subjects who are at high risk of developing Alzheimer's disease, so that we can initiate treatments very early and possibly even in asymptomatic patients," said Dr. Pasinetti. "However, for Alzheimer's disease patients who have already progressed into the initial stages of the disease, early intervention with this treatment might be beneficial as well. Our study implicating that these neurotoxins such as *56 in the brain are targeted by grape-derived polyphenols holds significant promise."

This research was funded by a grant from the National Institutes of Health. Dr. Giulio Pasinetti is a named inventor of a pending patent application filed by Mount Sinai School of Medicine (MSSM) related to the study of Alzheimer's disease. In the event the pending or issued patent is licensed, Dr. Pasinetti would be entitled to a share of any proceeds MSSM receives from the licensee.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by The Mount Sinai Hospital / Mount Sinai School of Medicine, via EurekAlert!, a service of AAAS.

Journal Reference:

Peng Liu, Lisa J. Kemper, Jun Wang, Kathleen R. Zahs, Karen H. Ashe, Giulio M. Pasinetti. Grape Seed Polyphenolic Extract Specifically Decreases *56 in the Brains of Tg2576 Mice. Journal of Alzheimer's Disease., Volume 26, Number 4, (in press)

Thursday, July 14, 2011

Are narrow blood vessels to blame in MS?

By Genevra Pittman

Reuters Health

Thursday, July 14, 2011

NEW YORK (Reuters Health) - Despite a few well-publicized studies and many hopeful patients waiting for treatment, there is no good evidence that multiple sclerosis, or MS, is caused by a blood vessel condition, a fresh look at the medical literature finds.

That means patients with MS shouldn't have surgery to open veins that connect the brain and spinal cord to the heart, researchers say.

"It's so appealing, the idea of a quick fix, of a surgical amelioration," Dr. Bridget Bagert, whose findings are published in the Archives of Neurology, told Reuters Health.

But, she added, "It's really not the right thing to do if the problem isn't established as being real."

MS occurs when the protective coating around nerve fibers begins to break down, slowing the brain's communication to the rest of the body. It's typically thought of as a disorder of the immune system and has no cure.

In 2009, however, Italian researchers led by Dr. Paolo Zamboni linked MS to a blood vessel condition called chronic cerebrospinal venous insufficiency, or CCSVI. The theory is that veins bringing blood from the brain and spine back to the heart become too narrow, causing some of that blood to leak back into the brain tissue.

Zamboni and his colleagues figured that might trigger inflammation, eventually leading to the balance and muscle problems seen in MS. Indeed, the Italian team's initial studies suggested that CCSVI is very common in MS patients and scarce in people without the disease.

But three independent studies published since then haven't found a clear link, according to the new report.

"That really casts a lot of doubt on to whether CCSVI exists at all, let alone whether or not it's the cause of MS," Bagert, from the Ochsner Clinic Foundation in New Orleans, told Reuters Health.

After Zamboni's initial findings were published, hopeful MS patients started requesting blood-vessel opening procedures, and a few doctors became well known in the MS community for being willing to perform them.

To determine if a person has CCSVI, a picture of the veins is taken using ultrasound or another type of scan. If the blood vessels look too narrow, doctors may open them up by inflating a small balloon in the veins.

Those procedures are typically used in people at risk of a heart attack, and they come with a risk of complications, including bleeding and infection.

But researchers said it's hard for doctors to even know what they're looking for on blood vessel scans, and whether anything that looks strange could be playing a part in MS symptoms.

"There's still considerable information and understanding that we don't have about this observation" on the role of CCSVI in MS, said Timothy Coetzee, chief research officer at the National Multiple Sclerosis Society in New York.

"There's no question that there has been considerable ambiguity and questions about some of the studies that were 100 percent (in favor of the link) and some that showed nothing," he told Reuters Health.

Bagert said there is also controversy over the methods used in the original Italian studies, which could have let potential investigator bias creep into the findings.

Because of the inconsistency in past reports, the National Multiple Sclerosis Society has spent more than $2 million funding research on how often blood vessel abnormalities show up in people with MS.

"Resolving this issue matters to a lot of people," said Coetzee, who was not involved in the new study.

He added that speculation about possible causes of MS -- which has included theories about infections and vitamin D -- is nothing new.

And as long as people with MS are well informed about the pros and cons of getting the procedure to open their blood vessels, he's not opposed to patients going ahead with the treatments for now.

But Dr. Ellen Marder of the University of Texas Southwestern Medical Center at Dallas, another author on the new paper, said the data doesn't support that idea.

"We don't think (CCSVI) is the cause of multiple sclerosis," she told Reuters Health. "We would not advise our patients to be tested for this or act on any recommendations based on this sort of testing."

Source: http://bit.ly/nwrGWI

Archives of Neurology, online July 11, 2011.

Exposure to Common Chemicals May Affect Thyroid Function

HealthDay News

Thursday, July 14, 2011

THURSDAY, July 14 (HealthDay News) -- Chemicals called phthalates and bisphenol-A (BPA) that are found in solvents, plastics and numerous household products may alter levels of thyroid hormones in the body, according to a new study.

Thyroid hormones play a role in many critical bodily functions, including reproduction and metabolism.

Researchers from the University of Michigan School of Public Health used data from the U.S. National Health and Nutrition Examination Survey to compare thyroid levels and traces of phthalates and BPA in urine samples of 1,346 adults and 329 teenagers. Their findings confirmed previous research linking BPA -- used in certain plastic water bottles and the linings of canned foods -- with disruptions in thyroid hormone levels, they said.

Overall, higher concentrations of the chemicals had an inverse impact on thyroid levels, said study lead author John Meeker, an assistant professor, in a university news release. The greater the exposure to phthalates and BPA, the lower the thyroid hormone levels.

The strongest link occurred with exposure to DEHP, a phthalate commonly used as a plasticizer, which people come into contact with through diet.

In the cases of DEHP ingestion, urine samples showed that the greatest exposure was associated with as much as a 10 percent drop in thyroid hormones.

"This seems like a subtle difference," said Meeker, "but if you think about the entire population being exposed at this level you'd see many more thyroid related effects in people."

The authors concluded that additional research is needed. In other ongoing studies, they are assessing the chemicals' potential effects on pregnancy outcomes and child development.

Developing fetuses and children may be particularly vulnerable to disruptions in thyroid hormone levels associated with exposure to these and other environmental chemicals, Meeker said.

The researchers, acknowledging some limitations of their study, said their work could be improved by following people over time and collecting several urine samples, since these chemicals metabolize quickly and one single sample may not represent the true chemical exposure.

The findings were published online July 11 in the journal Environmental Health Perspectives.

More information

The U.S. Department of Health and Human Services provides more information on the safety of phthalates and BPA.

Do tea, coffee drinkers have lower "superbug" risk?

By Amy Norton

Reuters Health

Thursday, July 14, 2011

NEW YORK (Reuters Health) - People who regularly drink tea or coffee may be less likely to carry the antibiotic-resistant "superbug" MRSA in their nostrils, a new study suggests.

Researchers found that of more than 5,500 Americans in a government study, those who drank hot tea or coffee were about half as likely as non-drinkers to harbor MRSA bacteria in their nostrils.

Exactly what it all means, though, is unclear.

MRSA (pronounced "mersa") stands for methicillin-resistant Staphylococcus aureus, a type of bacteria that causes staph infections that are resistant to several common antibiotics. In hospital patients, MRSA can cause life-threatening pneumonia or blood infections. In the general public, it typically causes painful skin infections, but those can sometimes develop into serious invasive infections.

A small segment of the population -- about one percent -- carries MRSA in the nose or on the skin but does not get sick.

For the new study, reported in the Annals of Family Medicine, researchers looked at whether coffee or tea drinkers were any less likely than other people to harbor MRSA in the nose.

The idea for the study came from the fact that, in both the lab dish and in humans, topically applied or inhaled tea extracts have shown some anti-MRSA activity, explained lead researcher Dr. Eric M. Matheson, of the University of South Carolina, Charleston.

Less research has been done on coffee compounds, he told Reuters Health, but there is some evidence of antibacterial powers there as well.

Matheson's team found that, indeed, tea and coffee drinkers were less likely to carry MRSA.

Overall, 1.4 percent of the study group harbored the bacteria in their noses. But those odds were about 50 percent lower among people who said they drank hot tea or coffee, versus non-drinkers.

The big caveat, though, is that the link does not prove that tea or coffee, themselves, are the reason for the lower risk.

The study shows an association between the two, Matheson said, "but you never can conclude causation from an association."

"I can't tell you that this finding isn't just a coincidence," he said.

The researchers tried to account for several other factors -- like whether differences in age, income or self-rated health explained the difference between tea or coffee drinkers and non-drinkers. And the beverages were still linked to lower odds of being a MRSA carrier.

But, Matheson said, there could still be other explanations for the connection.

For now, he stopped short of recommending that people start drinking coffee or tea in the hopes of fending off MRSA.

"Based on one association study, that would probably be saying too much," Matheson said.

Another question is, even if coffee and tea drinkers do have a lower chance of carrying MRSA, are they any less likely to get sick? Matheson said there is still debate about whether MRSA carriers are at increased risk of developing an active infection.

It's estimated that in 2005, MRSA caused severe infections in 95,000 Americans, killing nearly 19,000.

The rate of hospital infections has gone down in recent years, according to the Centers for Disease Control and Prevention, but MRSA infections in the general population have been on the upswing since the 1990s and have shown no reversal yet.

To cut the risk of contracting the superbug, experts advise that people regularly wash their hands, keep skin wounds covered, and avoid sharing personal items like towels, washcloths and razors.

And those preventive steps are key, Matheson noted, whether you're a java lover or not.

Source: http://bit.ly/qA66m7

Annals of Family Medicine, July/August 2011.

Certain Painkillers May Raise Odds of Stroke, Heart Attack: Study

HealthDay News

Thursday, July 14, 2011

THURSDAY, July 14 (HealthDay News) -- Heart disease patients with high blood pressure who take a class of painkillers called non-steroidal anti-inflammatory drugs (NSAIDs) are at greater risk for heart attack, stroke or even death, new research shows.

NSAIDS include popular medications such as such as aspirin, Celebrex, ibuprofen (Advil, Motrin) and naproxen (Aleve). The results are published in the July issue of The American Journal of Medicine.

"Among coronary artery disease patients with hypertension, chronic self-reported use of NSAIDs was associated with harmful outcomes, and this practice should be avoided where possible," Dr. Anthony A. Bavry, assistant professor in the division of cardiovascular medicine at the University of Florida, Gainesville, said in a journal news release.

In conducting the study, Bavry and colleagues followed 882 long-term NSAID users and almost 22,000 people who used NSAIDs intermittently over an average of about three years.

Patients with high blood pressure and coronary artery disease who took NSAIDs regularly had a 47 percent increase in the rate of death as well as nonfatal heart attack and stroke. After a period of five years, those rates jumped to 126 percent for death and 66 percent for heart attack, the investigators found.

Because there's a lack of data to help researchers understand why people with heart disease and high blood pressure who take NSAIDs are at greater risk for adverse events, the study authors suggested that these patients should consider alternative methods of pain relief until more research is done.

Commenting on the findings, Dr. Howard S. Weintraub, clinical director of the Center for the Prevention of Cardiovascular Disease and clinical associate professor of medicine at NYU Langone Medical Center in New York City, noted that the new study had several strengths.

"It is taken from a large group of patients with coronary artery disease in a generally older population," he said. "But the findings seem to cast more concern about the safety of NSAID's in higher risk patients. It is notable that the risk increased with higher blood pressure."

Still, he added, "one of the concerns about incriminating NSAID's is that the use of certain [cholesterol-lowering] drugs such as statins was lower in the chronic-use group. Hence, their [heart] risk could be expected to be higher. We are also not able to distinguish risk within the class."

"Once again it sounds like it is the length of use or perhaps more accurately the cumulative exposure to this class [that is driving the risk]. This would suggest that more occasional use could be okay," according to Weintraub.

Adding his perspective, Dr. Victor Khabie, co-chief of the Orthopedics and Spine Institute at Northern Westchester Hospital in New York, said that, "as an orthopedic sports medicine specialist I see a lot of baby boomers who use NSAIDs to ease their joint pain with sports. Perhaps acetaminophen or topical agents . . . should be considered in these individuals. Sports medicine specialists should be aware of the potential risk NSAIDs cause in this patient population and counsel their patients appropriately."

More information

The U.S. National Library of Medicine has more on pain relievers.

Vitamin A may not prevent asthma: study

By Genevra Pittman

Reuters Health

Thursday, July 14, 2011

NEW YORK (Reuters Health) - Despite the important role of vitamin A in lung development, researchers have found that giving the nutrient to pregnant women or preschoolers in Nepal doesn't protect kids against asthma.

But the findings don't mean vitamin A isn't important, especially in regions where vitamin deficiencies are common, according to the scientists.

Women taking vitamin supplements had a lower chance of dying during pregnancy, for instance. And those who took vitamin A while pregnant had kids with larger lungs, which have been linked to better survival.

"We're kind of narrowing down what the effect of vitamin A is," said Dr. William Checkley, from Johns Hopkins University in Baltimore, who worked on the study.

The lungs need vitamin A as they are developing and the nutrient is also involved in keeping lung tissue healthy over time, the researchers explain in the European Respiratory Journal.

In addition, previous studies hinted that people with lower levels of vitamin A in their blood are more likely to have asthma. But those kinds of studies, called observational studies, can't tease out cause and effect. Checkley and his colleagues wanted to see if by adding vitamin A to kids' or pregnant women's diets, they might lower the children's risk of asthma.

So the team followed up on two different trials that gave vitamin A or vitamin-free placebo pills to Nepalese women or kids.

The studies involved more than 5,000 kids and young adults, age nine to 23, who had gotten vitamin A or a placebo as preschoolers, or whose mothers had done so before and during pregnancy. All of them were living in an area of rural Nepal where vitamin deficiency is common.

Researchers asked all the kids if they had problems with wheezing or coughing or had ever had asthma. They also tested how well the kids' lungs were working using a device called a spirometer.

Between zero and two percent of the kids said they had had asthma at some point, and less than one percent currently did so -- with no differences between the placebo and vitamin groups.

There were no differences in how many kids reported wheezing or coughing in the two groups either, or in how well their lungs worked.

Still, Checkley said the findings might have looked different in another location.

"The effect of vitamin A may vary as to the setting," he told Reuters Health. "The prevalence (of asthma) was low in Nepal."

In the U.S., for example, nearly 10 percent of kids are diagnosed with the disease.

It's possible that in an urban area where asthma is more common to begin with, giving pregnant moms or kids vitamin A may better protect kids against asthma, Checkley said.

It's also not clear how the findings would apply to a population where vitamin A deficiency wasn't such a problem.

More than 300 million people worldwide have asthma, Checkley said, and increases in asthma rates have put researchers on a search for possible culprits. Pollution and allergies have been linked to asthma, and food and nutrition are other targets of investigation.

"Obviously diet is still one of those questions -- is it important or not?" Checkley said. Researchers are still wondering, "Can we prevent or reduce the risk of asthma by giving (vitamin A) supplements?"

So far, his work suggests the answer is no -- at least in this group of kids, in one part of the world.

Source: http://bit.ly/pHaFUy

European Respiratory Journal, online June 23, 2011.

Vitamin C from food tied to lower cataract risk

Reuters Health

Thursday, July 14, 2011

NEW YORK (Reuters Health) - Older adults who get very little vitamin C in their diets may have an increased risk of developing cataracts, a study in India finds.

Cataracts are a clouding of the eye's lens that commonly cause vision problems in older people. Some studies, but not all, have found that people with higher intakes of antioxidants, including vitamin C, may have a lower risk of developing the condition.

But those studies have been done in Western countries -- and not in lower-income countries like India, where people's vitamin C levels tend to be very low and rates of cataract are particularly high.

For the new study, researchers evaluated more than 5,600 Indian adults age 60 and up for cataracts. They also interviewed them about their diets and lifestyle habits, and measured their blood levels of vitamin C.

Overall, nearly 73 percent of the study participants were found to have cataracts. But that risk dipped as vitamin C blood levels and vitamin C intake rose.

In the roughly one-quarter of older adults with the highest vitamin C levels, the risk of cataract was 39 percent lower than in people with the lowest levels of the nutrient. That was with factors like income, smoking habits, high blood pressure and diabetes taken into account.

But vitamin C levels were generally very low. More than half of the study participants were deficient, and the bottom 30 percent of the group had vitamin C concentrations below the level of detection (2 micromoles per liter).

Anything below 11 micromoles per liter is considered a vitamin C deficiency.

Even in the group with the highest vitamin C levels, the typical amount was just 38 micromoles per liter. By comparison, in cataract studies in Europe and the U.S., the "high-C" groups have had levels of 70 micromoles or higher.

The findings, reported in the journal Ophthalmology, do not prove that adequate vitamin C protects against cataracts.

But it's biologically plausible, said senior researcher Astrid E. Fletcher, a professor at the London School of Hygiene & Tropical Medicine in the UK.

Vitamin C is an antioxidant, which means it helps protect body cells from damage caused by so-called oxidative stress.

"Laboratory and animal studies show vitamin C plays a very important part in defending the lens of the eye against oxidative stress," Fletcher explained in an email.

"The eye is particularly vulnerable to oxidative stress as the 'seeing' organ of the body," she added. "Light is essential for vision but light is also very damaging. The lens absorbs ultraviolet radiation, a major source of oxidative stress."

But that biological plausibility does not mean that older adults should load up on vitamin C supplements to ward off cataracts.

Fletcher said the current findings have relevance primarily for India, where people's vitamin C levels are generally low. They might also have implications for other lower-income countries, she added, but those studies have not been done yet.

In Western countries, studies have come to conflicting conclusions as to whether people with high vitamin C intakes have a lower cataract risk.

What's more, clinical trials that have tested high doses of vitamin C and other antioxidants for preventing cataracts have failed to show a benefit.

One reason, Fletcher noted, may be that well-nourished people in high-income countries already have fairly high vitamin C levels, and an extra dose from a pill has little benefit to offer. Vitamin C is water-soluble, and excess amounts are quickly excreted from the body.

Another possibility, according to Fletcher, is that taking a few nutrients in pill form simply does not mimic the effects of a good diet.

Foods high in vitamin C include citrus fruits like oranges and grapefruit, green and red peppers, kiwifruit, strawberries, broccoli and tomatoes. In the U.S., the official recommendation is for men to get 90 milligrams of vitamin C per day, while women should get 75 milligrams.

In this study, most older Indian adults were getting well below that.

If extra vitamin C was shown to lower cataract risk in India, the benefits could be substantial.

"India has the highest burden of blindness in the world," Fletcher said, "and the main cause is cataract."

Source: http://bit.ly/pdR2l1

Ophthalmology, online June 27, 2011.

Wednesday, July 13, 2011

Diesel Fumes Pose Risk to Heart as Well as Lungs, Study Shows

ScienceDaily

Wednesday, July 13, 2011

ScienceDaily (July 13, 2011) — Tiny chemical particles emitted by diesel exhaust fumes could raise the risk of heart attacks, research has shown. Scientists have found that ultrafine particles produced when diesel burns are harmful to blood vessels and can increase the chances of blood clots forming in arteries, leading to a heart attack or stroke.

The research by the University of Edinburgh measured the impact of diesel exhaust fumes on healthy volunteers at levels that would be found in heavily polluted cities.

Scientists compared how people reacted to the gases found in diesel fumes -- such as carbon monoxide and nitrogen dioxide -- with those caused by the ultrafine chemical particles from exhausts.

The research, funded by the British Heart Foundation, showed that the tiny particles, and not the gases, impaired the function of blood vessels that control how blood is channelled to the body's organs.

The 'invisible' particles -- less than a millionth of a metre wide -- can be filtered out of exhaust emissions by fitting special particle traps to vehicles. Particle traps are already being fitted retrospectively to public transport vehicles in the US to minimise the potential effects of pollution.

The results are published in the European Heart Journal.

Dr Mark Miller, of the University of Edinburgh's Centre for Cardiovascular Science, said: "While many people tend to think of the effects of air pollution in terms of damage to the lungs, there is strong evidence that it has an impact on the heart and blood vessels as well.

"Our research shows that while both gases and particles can affect our blood pressure, it is actually the miniscule chemical particles that are emitted by car exhausts that are really harmful.

"These particles produce highly reactive molecules called free radicals that can injure our blood vessels and lead to vascular disease.

"We are now investigating which of the chemicals carried by these particles cause these harmful actions, so that in the future we can try and remove these chemicals, and prevent the health effects of vehicle emissions"

Researchers want environmental health measures that are designed to reduce emissions to be tested to determine whether they reduce the incidence of heart attacks.

Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation, said: "We've known for a long time that air pollution is a major heart health issue and that's why we're funding this team in Edinburgh to continue their vital research. Their findings suggest that lives could be saved by cutting these harmful nanoparticles out of exhaust -- perhaps by taking them out of the fuel, or making manufacturers add gadgets to their vehicles that can trap particles before they escape. The best approach isn't clear yet.

"For now our advice remains the same -- people with heart disease should avoid spending long periods outside in areas where traffic pollution is likely to be high, such as on or near busy roads."

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Edinburgh, via EurekAlert!, a service of AAAS.

Journal Reference:

Nicholas L. Mills et al. Combustion-derived nanoparticulate induces the adverse vascular effects of diesel exhaust inhalation. European Heart Journal, July 13, 2011 DOI: 10.1093/eurheartj/ehr195

Immune System Suppression Linked to Blood Vessel Formation in Tumors

ScienceDaily

Wednesday, July 13, 2011

ScienceDaily (July 13, 2011) — Targeted therapies that are designed to suppress the formation of new blood vessels in tumors, such as Avastin (bevacizumab), have slowed cancer growth in some patients. However, they have not produced the dramatic responses researchers initially thought they might. Now, research from the Perelman School of Medicine at the University of Pennsylvania might help to explain the modest responses.

The discovery, published in the July 14 issue of Nature, suggests novel treatment combinations that could boost the power of therapies based on slowing blood vessel growth (angiogenesis).

The Penn investigators, led by George Coukos, MD, PhD, Celso-Ramon Garcia Professor of Reproductive Biology, found that ovarian cancer cells grown under low oxygen conditions -- which promote blood vessel formation -- secrete chemical signals that suppress the patient's immune system, preventing it from killing off the abnormal cancer cells.

"For the first time, we are realizing that the two programs -- angiogenesis and immune suppression -- are co-regulated and the two programs are mediated by the same cell types," Coukos says. "This creates new therapeutic opportunities, since the study reveals that in order to effectively suppress angiogenesis, one should also suppress a type of immune cell, called regulatory T cells.Thus, commonly used anti-angiogenesis therapies should be combined with therapeutic maneuvers that eliminate regulatory T cells."

Following hints that there might be cross-talk between the two systems, first author Andrea Facciabene, PhD, research assistant professor of Obstetrics and Gynecology, and colleagues grew ovarian cancer cells under normal oxygen conditions or low oxygen (hypoxic) conditions. When the team looked for differences in the proteins called chemokines secreted under the two growth conditions, they found that one signaling molecule, CCL28, was more abundant in low oxygen cultures. CCL28 was also commonly expressed in hypoxic areas of tumors in animal models.

The Penn investigators found that CCL28 recruited regulatory T cells (called T-regs) in experimental situations. Because T-regs suppress local immune responses, including immune cells that kill tumor cells, the researchers hypothesized that CCL28 signaling could induce immune tolerance. In fact, when they looked at tumors grown in animal models, they found that tumors engineered to express CCL28 grew significantly faster than tumors lacking CCL28 expression.

Together the data suggest that hypoxic conditions suppress the immune reaction through T regulatory cells while promoting blood vessel formation. Therefore, to get the most out of anti-angiogenesis drugs, clinicians might need to combine them with drugs that block T-regs.

"The tools to eliminate T-regs effectively are not presently available in the clinic, but the field is definitely advancing, with several candidate strategies currently being tested," Coukos said.

"The other implication of this study is that if anti-angiogenesis therapy induces tumor hypoxia, that could create a rebound increase in regulatory T cells," he continued. "That rebound could account for some of the resistance that is commonly seen in the clinic after anti-angiogenesis therapy is instituted."

Co-authors on the study include Xiaohui Peng, Klara Balint, Ian S. Hagemann, Andrea Barchetti, Li-Ping Wang, Phyllis A. Gimotty, Priti Lal, and Lin Zhang, all from Penn, and C. Blake Gilks of the University of British Columbia, Vancouver.

The study was funded through grants from the National Cancer Institute and the Ovarian Cancer Research Fund.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Pennsylvania School of Medicine.

Journal Reference:

Andrea Facciabene, Xiaohui Peng, Ian S. Hagemann, Klara Balint, Andrea Barchetti, Li-Ping Wang, Phyllis A. Gimotty, C. Blake Gilks, Priti Lal, Lin Zhang, George Coukos. Tumour hypoxia promotes tolerance and angiogenesis via CCL28 and Treg cells. Nature, 2011; 475 (7355): 226 DOI: 10.1038/nature10169

Tuesday, July 12, 2011 

Molasses Extract Decreases Obesity Caused by a High-Fat Diet

ScienceDaily

Tuesday, July 12, 2011

ScienceDaily (July 12, 2011) — Experimental results to be presented at the upcoming annual meeting of the Society for the Study of Ingestive Behavior (SSIB), the foremost society for research into all aspects of eating and drinking behavior, suggests that dietary supplementation with molasses extract may provide a novel approach for weight management in humans.

The study, conducted in mice by Richard Weisinger, Ph.D., investigated the impact of adding molasses extract to a high fat diet. Molasses extract is rich in polyphenols, a group of chemical compounds found in plants that are known for their antioxidant properties. Mice were given either an unaltered high fat diet, or the same diet supplemented with 2% or 4% molasses extract. After 12 weeks on these diets, mice that consumed the diet containing 4% molasses extract had lower body weight, reduced body fat, and decreased blood levels of leptin, a hormone produced by fat cells. However, mice consumed similar amounts of each diet. Additional studies showed that molasses supplementation led to increased energy excretion (that is, more calories lost in feces), and increased gene expression for several liver and fat cell biomarkers of energy metabolism.

"The addition of molasses extract to a high fat diet appears to reduce body weight and body fat levels primarily through reduced caloric absorption. Due to the increasing worldwide prevalence of obesity and associated health problems, supplementing food with molasses extract might be a way to address the escalating rates of overweight and obesity," said Weisinger. Clinical trials scheduled next year will provide the opportunity to evaluate the efficacy of molasses extract for weight control in humans.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Society for the Study of Ingestive Behavior.

More U.S. Men Die From Cancer Than Women: Study

By Steven Reinberg
HealthDay Reporter

HealthDay News

Tuesday, July 12, 2011

TUESDAY, July 12 (HealthDay News) -- Men in the United States are much more likely than women to die of cancer, a new report from the U.S. National Cancer Institute found.

Gender differences in cancer incidence -- more men than women develop cancer in the first place -- rather than differences in cancer survival appeared to drive the findings, the researchers said.

"If we can identify modifiable causes of sex difference in cancer incidence and mortality then preventative actions could reduce the cancer burden in both men and women," said lead researcher Michael B. Cook, a National Cancer Institute epidemiologist.

Cook said that for many cancers, male and female incidence rates, and by extension death rates, have changed disproportionately over time.

This is likely because of differences in "carcinogenic exposures, metabolism and susceptibility," he said. Increased rates of smoking among men, and differences in infections, hormones and contact with toxic metals may all come into play, he said.

In terms of survival, however, the gender gap was minimal, the researchers found.

The study is published in the August issue of Cancer Epidemiology, Biomarkers & Prevention.

To look for gender differences in cancer deaths and survival rates, Cook's team used information from the NCI's Surveillance, Epidemiology and End Results database, which includes information on survival and deaths for 36 different cancers.

Lip cancer, for example, killed 5.51 men for every 1 woman. Larynx cancer claimed the lives of 5.37 men for every 1 woman; throat cancer, 4.47 men for each woman; and urinary bladder cancer, 3.36 men per 1 woman.

Examining cancers with the highest death rates overall, the researchers again found higher mortality among men than women. For example, lung and bronchus cancer killed 2.31 men for every 1 woman. Liver cancer killed 2.23 men for every woman; colon and rectum cancer took 1.42 males' lives for every woman; pancreatic cancer, 1.37 men for each woman; and leukemia, 1.75 men for every woman.

The research team found that gender was not a major factor in five-year survival when age, year of diagnosis and tumor stage were taken into account.

"But, for certain cancers we did observe slight sex differences in survival," Cook said, adding it is difficult to assign any root cause to that observation.

"This is not really a novel finding," said Rebecca Siegel, an epidemiologist at the American Cancer Society, commenting on the study. "We know that men have a higher risk of developing and dying from cancer for a variety of reasons, and some reasons which we don't fully understand," she added.

"The fact they didn't find large differences in survival is comforting," she said.

The death rates reflect different smoking and drinking patterns, Siegel pointed out. Also, cancers related to work exposures are more common among men, she noted.

Because smoking among women peaked in the 1970s and 1980s, Siegel said she expects to see the gender difference in cancer deaths start to narrow.

Men may get diagnosed later than women because they tend to see their doctors less often, and this could affect mortality rates, Siegel also suggested.

Future studies should explore the factors responsible for the disparity, the study authors said.

More information

For more information on cancer, visit the American Cancer Society.

Indirubin, Component Of Chinese Herbal Remedy, Might Block Brain Tumor's Spread, Study Suggests

ScienceDaily

Tuesday, July 12, 2011 

ScienceDaily (July 12, 2011) — The active ingredient in a traditional Chinese herbal remedy might help treat deadly brain tumors, according to a new study by researchers at the Ohio State University Comprehensive Cancer Center -- Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC -- James).

The researchers discovered that the compound, indirubin, both blocks the migration of glioblastoma cells, preventing their spread to other areas of the brain, and the migration of endothelial cells, preventing them from forming the new blood vessels that the tumor needs to grow.

Glioblastomas occur in about 18,500 Americans annually and kill nearly 13,000 of them yearly. Glioblastoma multiforme is the most common and lethal form of the malignancy, with an average survival of 15 months after diagnosis.

The research is published online in the journal Cancer Research.

"We have pretty good methods to stop glioblastoma from growing in the human brain, but these therapies fail because tumor cells migrate from the original site and grow elsewhere in the brain," says co-principal investigator Dr. E. Antonio Chiocca, professor and chair of neurological surgery and co-director of the Dardinger Center for Neuro-oncology and Neurosciences.

"Our findings suggest that indirubins offer a novel therapeutic strategy for these tumors that simultaneously targets tumor invasion and angiogenesis," Chiocca says.

"This study shows for the first time that drugs of the indirubin family may improve survival in glioblastoma, and that these agents inhibit two of the most important hallmarks of this malignancy -- tumor-cell invasion and angiogenesis," says co-principal investigator Dr. Sean Lawler, senior scientist and group leader of the Translational Neurooncology Group at the Leeds Institute of Molecular Medicine.

Indirubin is derived from the Indigo plant. It is the active ingredient in the Chinese herbal remedy called Dang Gui Long Hui Wan, which is used to treat chronic myeloid leukemia.

Chiocca, Lawler and their collaborators used multiple glioblastoma cell lines and two animal models to examine three derivatives of indirubin. Key findings include the following:

When human glioblastoma cells were transplanted into one brain hemisphere of mice, indirubin-treated animals survived significantly longer than controls and showed no migration of tumor cells to the opposite hemisphere.

In a separate experiment, indirubin reduced the migration of tumor cells by 40 percent in treated animals versus controls.

Treated tumors showed a lower density of blood vessels, and new blood-vessel growth was reduced up to three-fold in intracranial tumors, depending on the tumor-cell line.

A laboratory assay showed that indirubins reduced endothelial-cell migration by 52 to 41 percent compared with untreated controls.

"Overall, our findings suggest that indirubins reduce tumor invasion and tumor vasculature because of their antimigratory effects on both tumor and endothelial cells," Chiocca says.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Ohio State University Medical Center, via EurekAlert!, a service of AAAS.

Journal Reference:

S. P. Williams, M. O. Nowicki, F. Liu, R. Press, J. Godlewski, M. Abdel-Rasoul, B. Kaur, S. A. Fernandez, E. A. Chiocca, S. E. Lawler. Indirubins decrease glioma invasion by blocking migratory phenotypes in both the tumor and stromal endothelial cell compartments. Cancer Research, 2011; DOI: 10.1158/0008-5472.CAN-10-3026

Scientists Spot Possible Target in Ovarian Cancer

HealthDay News

Tuesday, July 12, 2011

TUESDAY, July 12 (HealthDay News) -- Researchers seeking a way to beat cancer have found that a particular gene, known as PAX8, is altered in a significant number of ovarian tumors, according to a new study.

The research is part of Project Achilles, a comprehensive effort by scientists from the Broad Institute of MIT and Harvard, and the Dana-Farber Cancer Institute to identify weaknesses in cancers.

After analyzing the cells of more than 100 tumors, including 25 ovarian cancer tumors, the researchers reported that identifying genes like PAX8 might help in the battle against certain types of cancer.

"In this project, we're looking for all of the Achilles' heels of cancer. That is to say, we're looking for any instance where you inactivate a gene and affect the survival of cancer cells," William Hahn, a senior associate member of the Broad Institute and an associate professor at Dana-Farber and Harvard Medical School, said in an institute news release.

The researchers suppressed more than 10,000 genes in an attempt to find those needed for cancer cells to grow and survive. The PAX8 gene was identified in nearly one-fifth of the ovarian tumors analyzed.

"Not only can we characterize what genes are mutated or altered, but we can also simultaneously assess which of those are important functionally," Hahn said.

In identifying these specific genes, the investigators hope to predict the effect of treatments targeting specific genes. They also noted that going forward, it may be more telling to identify tumors based on genetic mutations rather than their organ or tissue of origin.

"Many of us in the genomics field . . . were thinking that maybe someday, we won't care about the organs that cancers come from, that we will only care about the genetic mutations that drive them," said Hahn.

In the near future, the researchers said they plan further investigation of the notoriously treatment-resistant PAX8 gene in order to find just one gene among hundreds of thousands capable of neutralizing it.

The study findings are published in the July 11 online edition of the Proceedings of the National Academy of Sciences.

More information

The U.S. National Cancer Institute provides more information on ovarian cancer.

Effects of Exercise On Meal-Related Gut Hormone Signals

ScienceDaily

Tuesday, July 12, 2011

ScienceDaily (July 12, 2011) — Research to be presented at the upcoming annual meeting of the Society for the Study of Ingestive Behavior (SSIB), the foremost society for research into all aspects of eating and drinking behavior, finds that alterations of meal-related gut hormone signals may contribute to the overall effects of exercise to help manage body weight.

Regular exercise is important in maintaining low body weight and also is known to facilitate weight loss in obese subjects. Running exercise is known to increase sensitivity to leptin, a hormone released from fat cells that inhibits food intake. The authors' new study reveals additional mechanisms that contribute the beneficial effects of exercise.

Gut hormones are released before and after a meal to initiate and terminate food intake. The authors measured gut hormone release after a palatable tasty meal before and after rats exercised in running wheels. In rats with a lot of running wheel experience, consuming a tasty meal led to increased blood levels of an inhibitory feeding hormone, amylin. After the meal, the same rats showed a more rapid rebound of a stimulatory feeding hormone, ghrelin. The authors also demonstrated that compared to sedentary control rats, exercise-experienced rats decrease their food intake more robustly after treatment with CCK, a gut hormone that limits meal size.

Dr. Nu-Chu Liang reports, "Our new results indicate that the beneficial effects of exercise to control body weight might occur by altering the way in which meals release gut hormones that regulate food intake, and also by changing the sensitivity of individuals to these gut hormone signals. Furthermore, these findings suggest that both body and brain mechanisms are involved in the effects of exercise to modulate food intake."

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Society for the Study of Ingestive Behavior.

Alzheimer's Brain Protein Scanning Moves Forward

By By Ellin Holohan
HealthDay Reporter

HealthDay News

Tuesday, July 12, 2011

TUESDAY, July 12 (HealthDay News) -- The use of brain scans to diagnose Alzheimer's disease may have just taken a small step forward.

Longer-lasting radioactive "tracers" used in the brain-scanning process could allow wider use of the imaging technique that, to date, has required costly equipment, according to two new studies funded by the manufacturers of the tracers.

PET scans, or brain scans, create images using the tracers, known as florbetapir and flutemetamol. Using the images, doctors diagnose the existence of beta-amyloid, the protein plaques in the brain linked to Alzheimer's disease.

Before now, PET scans (positron emission tomography) could only be done in a facility that owned a cyclotron, a particle accelerator used to make radioactive material, because the tracer compound needed to do the scan did not last long enough to transport it.

The new imaging compounds last much longer, and once produced, can be transported and used in the scanning technology.

The two new studies are published online July 11 in Archives of Neurology.

In one study, conducted by Dr. Adam S. Fleisher at the Banner Alzheimer's Institute in Phoenix, Ariz., researchers compared brain images of 68 people with probable Alzheimer's disease to 60 participants with mild cognitive, or memory, problems and 82 healthy volunteers. The participants were mostly in their early to mid-70s.

The study found a high correlation between PET scan readings for amyloid and both the disease, and milder symptoms. Healthy adults showed only very low levels of amyloid.

Fleisher said, however, that not enough is known to use the procedure for routine screenings.

"Without anti-amyloid therapy available, there are ethical questions regarding using this type of imaging as a screening tool for patients without any symptoms " because no treatment could be offered, Fleisher said.

In the other study, conducted by Dr. David Wolk at the University of Pennsylvania in Philadelphia, researchers compared brain tissue samples of seven patients undergoing a procedure for hydrocephalus (a degenerative brain disease) with PET scans performed at a later date. People with hydrocephalus often also have Alzheimer's.

The Pennsylvania researchers found a high correlation between amyloid in the brain tissue and PET scans showing the plaque. The average age of patients in that study was 70.

A big issue for research is being able to test drugs on people who actually have Alzheimer's, said Wolk, assistant director of the Penn Memory Center in Philadelphia.

By helping to diagnose Alzheimer's early, PET scans using the new tracers will improve drug testing, treatment and prevention, Wolk added.

Wolk's study was sponsored by GE Healthcare, which manufactures flutemetamol. Fleisher's study was supported by funding from Avid Radiopharmaceuticals, a subsidiary of Eli Lilly and Co., which manufactures florbetapir.

One expert agreed that the longer-lasting tracers could help speed progress in treating the disease.

"There are a couple of different potential uses, both in terms of current clinical care, but more importantly for the future for testing drugs that may be able to intervene in the disease process," said Dr. Marc Gordon, a neurologist at the Feinstein Institute for Medical Research in Manhasset, N.Y.

By improving early diagnosis, the technology will be useful in identifying the "correct population" for drug testing when patients are "pre-symptomatic," before dementia occurs, said Gordon.

Alzheimer's disease affects about 5 million Americans, 90 percent over the age of 65, according to the National Institutes of Health. But another form of the illness, "early onset" Alzheimer's, can develop in the 30s, 40s or 50s, is genetically based and runs in families, the NIH says. Genetic and lifestyle factors contribute to the late onset of the disease.

The presence of amyloid doesn't mean someone will "necessarily develop Alzheimer's," said Gordon, noting that about 30 percent of elderly people have plaque, but not Alzheimer's.

There are some drugs for treating Alzheimer's, the most common form of dementia, but they don't slow the disease. Their benefits are "modest, they are not cures," said Gordon.

In June, a study presented at a Society of Nuclear Medicine meeting suggested that PET scans for detecting Alzheimer's could be commercially available this year, although experts said such scans could be expensive. In the past, diagnosis has relied on psychological tests and family reports.

More information

To learn more about Alzheimer's, visit the U.S. National Institutes of Health.

Seven in One Blow: Scientists Discover DNA Regions Influencing Prostate Cancer Risk

ScienceDaily

Tuesday, July 12, 2011

ScienceDaily (July 12, 2011) — Doctors have known for a long time that prostate cancer "runs in the family." Men with relatives who have been diagnosed with prostate cancer have an elevated risk of also developing this type of cancer. It was only last year that DKFZ scientists calculated that this risk rises with the number of affected direct family members and also depends on the relatives' age at outbreak of the disease.

The exact DNA variants that contribute to prostate cancer risk have now been published by an international research consortium with participation of scientists from the German Cancer Research Center. In a multi-stage study, the collaborators systematically searched the whole genome of cancer patients and healthy controls for specific gene variants. Then they calculated whether specific variants are found more often in patients than in healthy people.

Professor Dr. Hermann Brenner, one of the DKFZ researchers participating in the consortium, explains: "Each of these gene variants taken on its own is associated with only a slight increase in prostate cancer risk by a few percent. However, by taking account of the different variants at the same time it becomes possible to identify groups of persons who have a significantly elevated risk. Examining the genetic material for such risk variants might therefore improve medical consultation on the prevention and early detection of prostate cancer in the future."

Such DNA variants are scientifically called single nucleotide polymorphisms (SNPs). They are defined as a single variation of a nucleotide which occurs with varying frequency in the whole population. If a relationship in numbers is found between a particular SNP and cancer incidence, researchers conclude that a gene within the affected DNA region plays a role in cancer.

The first two study stages conducted by the consortium had already identified 16 SNPs in 16 different DNA regions to be associated with an elevated prostate cancer risk. Together with the results of prior association studies, about 30 risk genes for prostate cancer were known then. In the third and last round the research consortium searched in 4,574 cancer patients and 4,164 controls for another 1,536 SNPs. The emerging associations with cancer risk were then verified once more using 51,311 DNA samples of cancer patients and healthy men.

Alongside a number of already identified variants, the investigators found seven SNPs that emerged for the first time in association with an elevation in prostate cancer risk. The variants are all located in DNA regions that also contain genes for which the scientists consider it plausible that they play a role in carcinogenesis. However, an association with the malignancy of cancer could not be established for any of these variants. With the seven newly discovered DNA regions, scientists are now able to explain about 25 percent of familial cancer risk.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Helmholtz Association of German Research Centres, via EurekAlert!, a service of AAAS.

Journal Reference:

Zsofia Kote-Jarai et al. Seven prostate cancer susceptibility loci identified by a multi-stage genome-wide association study. Nature Genetics, 2011; DOI: 10.1038/ng.882

Monday, July 11, 2011

Psoriatic Arthritis Patients Seem to Lack Enough Vitamin D

HealthDay News

Monday, July 11, 2011

MONDAY, July 11 (HealthDay News) -- Vitamin D insufficiency is common among people with psoriatic arthritis, but levels of the vitamin in the blood do not affect disease activity, a new study finds.

People with psoriatic arthritis have the chronic skin disorder psoriasis accompanied by inflammatory arthritis.

The study, published in the July 11 issue of the journal Arthritis Care & Research, included more than 300 patients living in Toronto and Haifa, Israel, two geographically diverse locations. Vitamin D levels in the blood -- known as 25-hydroxyvitamin D [25 (OH) D] -- were measured in the summer and winter.

Vitamin D is produced by the skin in response to exposure to sunlight. It is also found in certain foods, including eggs, fish and fortified foods such as dairy products and breakfast cereals.

In the Canadian patients, 56 percent had insufficient 25 (OH) D levels during the winter and 59 percent had insufficient levels during the summer. In the Israeli patients, 51 percent had insufficient levels in the winter, and 62 percent had insufficient levels in the summer, the investigators found.

Vitamin D deficiency was found in 3 percent of the Canadian patients only in winter, 4 percent of Israeli patients in winter, and 1 percent of Israeli patients in summer.

Seasonal or geographic differences in vitamin D levels were not statistically significant, and vitamin D levels did not affect disease activity, concluded lead author Dr. Dafna Gladman, director of the University of Toronto Psoriatic Arthritis Clinic, and colleagues.

However, further research is required to determine if psoriatic arthritis patients require a higher-than-normal intake of vitamin D in order to maintain healthy levels, the researchers pointed out in a journal news release.

More information

The National Psoriasis Foundation has more about psoriatic arthritis.

Do-It-Yourself Brain Repair Following Stroke

ScienceDaily

Monday, July 11, 2011

ScienceDaily (July 11, 2011) — Stroke is a leading cause of long-term disability and death in the United States. A team of researchers -- led by Gregory Bix, at Texas A&M College of Medicine, College Station -- has identified a way to exploit one of the brain's self-repair mechanisms to protect nerve cells and enhance brain repair in rodent models of stroke. The authors suggest that this approach could provide a nontoxic treatment for stroke.

The most common form of stroke (ischemic stroke) occurs when a blood vessel that brings oxygen and nutrients to the brain becomes clogged, for example with a blood clot, causing nerve cells in the affected area to die rapidly. In their study, Bix and colleagues detected in rodent models of stroke elevated levels of domain V, a naturally occurring fragment of the molecule perlecan, suggesting it might have a natural role in repairing the brain after a stroke.

When administered in these models 24 hours after stroke, perlecan domain V protected nerve cells from death and promoted blood vessel growth, a key component of brain repair. The authors therefore suggest that perlecan domain V could provide a therapy that improves stroke outcome by protecting nerve cells and enhancing brain repair.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Journal of Clinical Investigation, via EurekAlert!, a service of AAAS.

Journal Reference:

Boyeon Lee, Douglas Clarke, Abraham Al Ahmad, Michael Kahle, Christi Parham, Lisa Auckland, Courtney Shaw, Mehmet Fidanboylu, Anthony Wayne Orr, Omolara Ogunshola, Andrzej Fertala, Sarah A. Thomas, Gregory J. Bix. Perlecan domain V is neuroprotective and proangiogenic following ischemic stroke in rodents. Journal of Clinical Investigation, 2011; DOI: 10.1172/JCI46358

Folic acid tied to better grades in Swedish teens

By Frederik Joelving

Reuters Health

Monday, July 11, 2011

NEW YORK (Reuters Health) - Swedish teenagers who consumed more folic acid got better school grades, a small study published in the journal Pediatrics has found.

But don't run out and stock up on the B vitamin with the rest of your school supplies just yet, one expert warns.

"There is very little deficiency of folic acid in North America," Deborah O'Connor, a nutrition researcher who was not involved in the study, told Reuters Health. "If you're already sufficient, there is not a lot of evidence that taking more supplements will help."

She said the teens in the study might have been deficient in folic acid, with levels a few times lower than what's typically seen in North American kids.

Because a lack of the nutrient during pregnancy can cause severe birth defects in babies, certain foods are fortified with folic acid, also called folate, in North America. Most of the population is thought to get adequate amounts for that reason.

During the study, Sweden did not fortify foods, nor did kids use a lot of supplements. Folic acid is naturally present in green, leafy vegetables and legumes.

The new study is among the first to examine whether folate is tied to school achievements, according to Dr. Torbjorn Nilsson of Orebro University Hospital and his colleagues.

The researchers looked at 386 15-year-olds who were finishing up ninth grade. When all their grades from ten core classes were added up, there was a clear difference between teens who got the most and the least folic acid in their diets.

Teens in the top third of folic acid intake -- more than 253 micrograms per day for girls and 335 for boys -- scored grades of 139 out of 200, on average. Those in the bottom third -- less than 173 micrograms folic acid per day for girls and 227 for boys -- had an average score of only 120.

The differences remained even after the researchers accounted for gender, smoking, the mothers' education and which schools the kids went to.

O'Connor, of the University of Toronto and the Hospital for Sick Children in Ontario, Canada, called the findings "pretty significant."

Still, she said, you can't be sure if the kids who performed better had a better diet in general or if some other hidden factor could explain the results.

"It's not a randomized controlled trial, so you always wonder, are there other things going on that you weren't able to control for?" she said. "Like most studies, it probably raises more questions than it answers."

In the U.S., kids aged 9 to 13 should get a total of 300 micrograms of folate a day from food and supplements according to the Institute of Medicine's "Dietary Reference Intakes." Kids 14 and older and adults are urged to get 400 micrograms a day and pregnant women should get 600 micrograms.

Source: http://bit.ly/cxXOG

Pediatrics, online July 11, 2011.

Older Adults Have to Exercise More to Maintain Muscle Size, Study Finds

HealthDay News

Monday, July 11, 2011

MONDAY, July 11 (HealthDay News) -- Older adults have to exercise more than younger adults in order to maintain muscle size, according to a new study.

Researchers examined how much exercise was needed to maintain or increase muscle mass, size and strength in adults ages 20 to 35 and ages 60 to 75.

In the 16-week first phase of the study, all the participants did three sets of resistance training exercises (leg press, knee extensions and squats) three times a week. In the 32-week second phase, participants were dividing into three groups: some were assigned to stop resistance training altogether, some were told to reduce training to one day a week, and others were asked to cut down training to one day and one set of resistance exercises (as opposed to three sets) a week.

In the younger adults, muscle size was maintained in both groups that reduced their training. This was not the case in the older adults, whose muscle size shrank even if they did one to three sets of the exercises one day a week.

However, one day of resistance training a week was enough for both younger and older adults to maintain their strength -- at least for an extended period of time.

"We are not advocating that people only train one day a week indefinitely, but we do believe such a program can be effective during temporary periods when it is difficult to maintain a consistent, intensive exercise regimen several days per week," study leader Marcas Bamman, of the University of Alabama at Birmingham, said in a news release from the American College of Sports Medicine.

The study appears this month in the journal Medicine & Science in Sports & Exercise.

"Our data are the first to suggest that older adults require greater weekly maintenance dosing than younger individuals to maintain resistance-training-induced increases in muscle mass," Bamman added.

Bamman said all adults "should include progressive resistance exercise in their weekly regimen, but there will always be times, such as extended travel or a family illness, when exercise is difficult to sustain." In such cases, the study suggested, resistance exercises once a week are certainly better than none.

More information

The U.S. Centers for Disease Control and Prevention has more about strength training for older adults.

High salt + low potassium = early death: study

By Julie Steenhuysen

Reuters

Monday, July 11, 2011

CHICAGO (Reuters) - Put down the salt shakers. Eating too much salt and too little potassium can increase the risk of death, U.S. government researchers said on Monday.

The findings from a team at the U.S. Centers for Disease Control and Prevention are a counterpoint to a fiercely-debated study released last week that found no evidence that making small cuts in salt intake lowers the risk of heart disease and premature death.

"Salt is still bad for you," said Dr. Thomas Farley, Health Commissioner for New York City, which is leading a campaign to reduce salt in restaurant and packaged foods by 25 percent over five years.

Most health experts agree with Farley that consuming too much salt is not good for you and that cutting salt intake can reduce high blood pressure, which raises the risk of heart attack and stroke. Salt intake has been rising since the 1970s, with Americans consuming about twice the recommended daily limit.

The CDC study, published in the Archives of Internal Medicine, specifically focused on growing research that shows a diet high in salt and low in potassium is especially risky.

Farley, who wrote an editorial on the CDC study, said it is one of the best yet looking at the long-term effects of eating too much salt.

"It is entirely consistent with what we've said all along about sodium intake," Farley said in a telephone interview.

For the study, researchers looked at the long-term effects of sodium and potassium intake as part of a 15-year study of more than 12,000 people.

By the end of the study period, 2,270 of the study participants had died; 825 of these deaths were from heart disease and 433 were from blood clots and strokes.

Potassium Is Key

They found that people who had a high salt intake and a low potassium intake were most at risk.

"People who ate a diet high in sodium and low in potassium had a 50 percent increased risk of death from any cause, and about twice the risk of death -- or a 200 percent increase -- from a heart attack," said Dr. Elena Kuklina of the CDC who helped lead the study.

She said consumers need to increase the levels of potassium in their diet by adding more servings of fresh fruits and vegetables, such as spinach, grapes, carrots, sweet potatoes, and low fat milk and yogurt.

The Salt Institute, an industry group, challenged the findings, pointing out that the CDC study found that the link between salt intake and heart disease was statistically insignificant.

"This is a highly flawed publication that reveals more about the anti-salt agenda being pursued by the CDC than about any relationship between salt and health," said Mort Satin, the Salt Institute's Director of Science and Research.

"The only significance is between low potassium and mortality," Satin said in a statement.

Dr. Robert Briss, director of the National Center for Chronic Disease Prevention and Health Promotion at the CDC, said the findings support the general weight of evidence and suggests that higher doses of sodium are linked with poor health consequences.

And it suggests "that higher potassium may be better for you," Briss said in a telephone interview.

"About 90 percent of Americans consume more sodium than is recommended. This impacts their blood pressure," Briss said.

"Most of that sodium is not related to the salt shaker but it is in foods and especially processed and restaurant foods that we buy and order from restaurants. Consumers, even motivated ones, don't have as much choice as they could," he said.

Kuklina said potassium often counteracts the effects of salt in the diet. This equilibrium is affected when people eat highly processed foods, which tend to increase sodium levels and decrease potassium content.

"If sodium increases your high blood pressure, potassium decreases it. If sodium retains water, potassium helps you get rid of it," she said.

Instead of focusing only on salt, Kuklina said researchers should focus on the balance between potassium and salt.

"We need to strive to do both -- decrease your sodium intake and increase your potassium intake," she said.

(Editing by Sandra Maler)

ADHD, Learning Issues May Be Linked to Secondhand Smoke

By By Randy Dotinga
HealthDay Reporter

HealthDay News

Monday, July 11, 2011

MONDAY, July 11 (HealthDay News) -- Children exposed to secondhand smoke in their homes face a higher risk of developing attention-deficit/hyperactivity disorder, other behavioral problems and learning disorders, a new study finds.

The research doesn't definitively prove that tobacco smoke can harm children's brains, and it doesn't say how much smoke is too much. However, it does add to the evidence that children may be especially vulnerable to the effects of smoke exposure.

"They're in a developmental stage and their body is growing," potentially putting them at greater risk of disruptions to their brains than adults, said study co-author Hillel R. Alpert, a research scientist at Harvard School of Public Health's Center for Global Tobacco Control in Boston.

It's difficult to confirm whether secondhand smoke causes children's health problems because it would be unethical to expose kids to smoke and watch what happens to them. Instead, researchers often must look backward, as they did in this study, and try to eliminate all explanations but one for a link between smoke exposure and illness.

For their study, published online July 11 in the journal Pediatrics, researchers examined the results of a 2007 U.S. telephone survey of families that included 55,358 children under the age of 12. Six percent of them were exposed to secondhand smoke in the home.

After adjusting their numbers to improve their validity from a statistical point of view, the researchers found that about 8 percent of the kids had learning disabilities, 6 percent had attention-deficit/hyperactivity disorder, and almost 4 percent had behavioral and conduct disorders, such as oppositional defiant disorder.

Those who lived in homes with smokers were more likely to have at least two of the conditions, even after the researchers adjusted their statistics to account for such factors as income and education levels of parents.

The researchers estimated that secondhand smoke may be responsible for 274,100 extra cases of the three types of disorders examined.

Older children, particularly those between 9 and 11 years old, boys and poor children were most at risk of developing the disorders as a result of smoke exposure, the researchers found.

Children with smoke exposure at home were also more likely to receive behavioral counseling or treatment, which greatly increases health care costs, the survey found.

"Parents should consider banning smoking from their homes," Alpert said.

No only are children vulnerable because of their physiology, "they're also vulnerable because they do not necessarily have the choice about being exposed to smoke or not," he added.

According to the U.S. Environmental Protection Agency, secondhand smoke has been linked to increased severity of asthma in 200,000 to 1 million children and 150,000-300,000 lower respiratory tract infections in babies. Secondhand smoke is also linked to increased risk of sudden infant death syndrome.

Based on the survey results, the researchers concluded that about 4.8 million U.S. children under the age of 12 live in homes with a smoker, which is slightly less than previous estimates.

More information

For more on secondhand smoke, visit the U.S. Environmental Protection Agency.

Sunday, July 10, 2011 

Vitamin D Lower in NFL Football Players Who Suffered Muscled Injuries, Study Suggests

ScienceDaily

Sunday, July 10, 2011

ScienceDaily (July 10, 2011) — Vitamin D deficiency has been known to cause an assortment of health problems. Now, a recent study -- being presented at the American Orthopaedic Society for Sports Medicine's (AOSSM) Annual Meeting in San Diego -- suggests that lack of the vitamin might also increase the chance of muscle injuries in athletes, specifically NFL football players.

"Eighty percent of the football team we studied had vitamin D insufficiency. African American players and players who suffered muscle injuries had significantly lower levels," said Michael Shindle, MD, lead researcher and member of Summit Medical Group.

Researchers identified 89 football players from a single NFL team and provided laboratory testing of vitamin D levels in the spring 2010 as part of routine pre-season evaluations. The mean age of the players was 25. The team provided data to determine the number of players who had lost time due to muscle injuries. Vitamin D levels were then classified based on player race and time lost due to muscle injury.

Twenty-seven players had deficient levels (< 20 ng/ML) and an additional 45 had levels consistent with insufficiency (20-31.9 ng/mL). Seventeen players had values within normal limits (>32 ng/mL). The mean vitamin D level in white players was 30.3 ng/mL while the mean level for black players was 20.4 ng/mL. Sixteen players suffered a muscle injury with a mean vitamin D level of 19.9.

"Screening and treatment of vitamin D insufficiency in professional athletes may be a simple way to help prevent injuries," said Dr. Scott Rodeo, MD, Co-Chief of the Sports Medicine and Shoulder Service at the Hospital for Special Surgery. "Further research also needs to be conducted in order to determine if increasing vitamin D leads to improved maximum muscle function," said Dr. Joseph Lane, MD, Director of the Metabolic Bone Disease Service at the Hospital for Special Surgery."

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Orthopaedic Society for Sports Medicine, via EurekAlert!, a service of AAAS.