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4 December 2009

The Flu Fighters—in Your Food

While many people are still waiting for swine-flu vaccine to become available in their area, there is a lot they can do in their own kitchens to help fight off disease and build a strong immune system.

Scientists in the growing field of nutritional immunology are unveiling new evidence of the complex role that nutrition plays in fighting off infectious diseases like influenza. A diet rich in nutrients such as vitamin A, found in colorful fruits and vegetables, and zinc, found in seafood, nuts and whole grains, can provide the critical fuel the body needs to fight off disease, heal injuries, and survive illness when it does strike, experts say.

Scientists are still studying all the complex ways in which nutrients interact with the immune system. There is still much that they don't know about minerals such as zinc, for instance, including how they are absorbed and all the roles they play in the body. But scientists do know that certain vitamins and minerals can improve the body's ability to fight off infection: Studies in healthy elderly adults, for example, have shown an improved immune response to vaccination and fewer infections after receiving extra doses of vitamin E.

To create immune cells to fight off a specific infection, the body has to rapidly draw nutrients from the bloodstream, says Anuraj Shankar, a researcher at the Harvard School of Public Health. "If you don't have an adequate intake of vitamins and minerals, you won't be able to produce the number of immune cells you need, and the immune cells you do produce may be compromised," Dr. Shankar says. That makes it impossible to mount an effective response to infection, he says.

The benefits of good nutrition may have been recognized first by Hippocrates, the ancient Greek physician who declared "let food be thy medicine, and medicine be thy food." An 18th century naval surgeon's discovery that citrus fruits could cure scurvy in sailors was later recognized as a vitamin C deficiency, and after the 1930s, when dairies began to fortify milk with vitamin D, the disease known as rickets was virtually eliminated in the U.S.

Researchers warn that malnourished people may be a breeding ground for more dangerous infectious diseases. Animal studies at the University of North Carolina show that in a host with poor nutrition, viruses mutate in the face of a weak immune response to become more powerful. And once those mutations occur, even well-nourished hosts are susceptible to the newly virulent virus. "A lot of people may think malnutrition on the other side of the world isn't their problem," says Melinda A. Beck, a researcher at the University of North Carolina, Chapel Hill. But malnutrition "is a driving force in emerging infectious diseases that are spreading around the world," she says.

The human body doesn't have to be starving to suffer from malnutrition. Studies show that obesity, in addition to its other health risks, may also make people more susceptible to infections like the flu. A diet heavy on processed and fast foods may be low in the vitamins and minerals important for health. And diets that are high in saturated fat appear to actually depress the body's immune response, increasing the risk of infections.

Dr. Beck says studies of mice show that only 4% of lean animals infected with the flu virus die. That compares with a death rate of between 40% and 60% in obese mice infected with the virus. And after a small study showed that obese people vaccinated for the flu didn't mount a strong immune response, the University of North Carolina is expanding its trials to compare vaccination response rates in lean and obese people.

3 December 2009

Diabetes expected to double, costs to triple by 2034

According to estimates from researchers at the University of Chicago, the total number of Americans with diabetes will double in the next 25 years, from the current 23.7 million to some 44.1 million in 2034. During that same time frame, annual costs for treating those patients are expected to soar—nearly tripling from the current $113 billion to some $336 billion.

If these new estimates seem troubling, they are, and what's more concerning is that they may even be on the conservative side. The figures, published in the December issue of the journal Diabetes Care, are based on obesity levels remaining stable over the next few decades. The authors based their calculations on the belief that obesity levels will plateau, and even decline, by 2033. Yet, if actual prevalence outpaces these estimates, the cases of diabetes, and resulting costs, could be even higher.

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These new estimates paint a grim vision of the future, but, the researchers say, a realistic one. Past estimates too indicated a surge in diabetes cases, but often dramatically underestimated just how quickly the problem would grow. Researchers point to figures from 1991, which projected that some 11.6 million Americans would have diabetes by 2030. In fact, that's fewer than half of the total number of Americans with diabetes today, two decades earlier than researchers had predicted.

Later research similarly undershot the magnitude of the problem. In 1998, researchers estimated there would be 22 million cases of diabetes in the U.S. by 2025. Yet, the University of Chicago team points out, we've already passed that mark—and more than 15 years earlier than anticipated.

Going forward, the incredible surge in diabetes cases and correspondingly high medical costs will largely depend on the aging population of Baby Boomers. Currently some 8.2 million diabetes patients are covered by Medicare, costing $45 billion per year. By 2034, researchers estimate that 14.6 billion diabetes patients will be covered by Medicare, and costs will balloon to a staggering $171 billion.

The study, which was originally conducted to help analyze long-term implications of the different proposals for future health care policy, underscores the essential nature of tackling this problem while it is still of relatively manageable size. And how exactly can we stop it from steamrolling into the coming decades? It's no small feat, the researchers say: as a nation, we need to completely overhaul our eating and exercise habits, and find practical, applicable ways to curb the cost of treating diabetes.

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Exercise Prevents Aging of Cells

Exercise is known to have a bounty of health benefits that can ward off age-related diseases, but a new study shows that regular physical activity has an anti-aging effect at the cellular level.

The research found that intensive exercise prevents the shortening of telomeres — the DNA that bookends chromosomes and protects the ends from damage — much like the cap on the end of a shoelace.

The shortening of telomeres limits cells to a fixed number of divisions and can be regarded as a "biological clock." Gradual shortening of telomeres through cell divisions leads to aging on the cellular level and may limit lifetimes. When the telomeres become critically short, the cell dies.

The researchers measured the length of telomeres in blood samples from two groups of professional athletes and two groups who were healthy nonsmokers, but not regular exercisers.

"The most significant finding of this study is that physical exercise of the professional athletes leads to activation of the important enzyme telomerase and stabilizes the telomere," said Ulrich Laufs, the study's lead author and professor of clinical and experimental medicine at Saarland University in Homburg, Germany.

"This is direct evidence of an anti-aging effect of physical exercise," Laufs said. "Physical exercise could prevent the aging of the cardiovascular system, reflecting this molecular principle."

In addition, the animal studies of Laufs and colleagues show that exercise exerts important cellular functions beyond the regulation of telomere length, such as protecting the cell from deterioration and programmed cell death.

In the clinical study, the researchers analyzed 32 young professional runners, average age 20, from the German National Team of Track and Field. They compared the young professional athletes with middle-aged athletes who had a history of continuous endurance exercise since their youth.

The two groups were evaluated against untrained athletes who were healthy nonsmokers, but who did not exercise regularly. They were matched for age with the professional athletes.

Long-term exercise training activates telomerase and reduces telomere shortening in human white blood cells, the researchers found. The age-dependent telomere loss was lower in the older athletes who had performed endurance exercising for several decades.

"Our data improves the molecular understanding of the protective effects of exercise on the vessel wall and underlines the potency of physical training in reducing the impact of age-related disease," Laufs said.

The study will be published in December in Circulation, a journal of the American Heart Association.

The Claim: Exercise More During the Day, and You Will Sleep Better at Night

THE FACTS It has long been said that regular physical activity and better sleep go hand in hand. Burn more energy during the day, the thinking goes, and you will be more tired at night.

But only recently have scientists sought to find out precisely to what extent. One extensive study published this year looked for answers by having healthy children wear actigraphs — devices that measure movement — and then seeing whether more movement and activity during the day meant improved sleep at night. The results should be particularly enlightening to parents.

The study found that sleep onset latency — the time it takes to fall asleep once in bed — ranged from as little as roughly 10 minutes for some children to more than 40 minutes for others. But physical activity during the day and sleep onset at night were closely linked: every hour of sedentary activity during the day resulted in an additional three minutes in the time it took to fall asleep at night. And the children who fell asleep faster ultimately slept longer, getting an extra hour of sleep for every 10-minute reduction in the time it took them to drift off.

Studies on adults have reached generally similar results, showing that an increase in physical activity improves sleep onset and increases sleep duration, particularly in people who have trouble sleeping.

THE BOTTOM LINE Studies suggest that being more physically active can lead to better sleep.

1 December 2009

New study questions effectiveness of popular cholesterol drugs

By Lyndsey Layton
Washington Post Staff Writer
Monday, November 16, 2009

A widely prescribed and expensive cholesterol drug is not as effective as niacin, a cheap vitamin, in helping to unclog coronary arteries in people already taking statins, the standard medicines used to lower cholesterol, according to a new study.

The research, which appears Monday in the New England Journal of Medicine, is sending rumbles through the medical community because it is the third recent study to raise questions about the effectiveness of Zetia and its sister drug, Vytorin, highly profitable pharmaceuticals made by Merck & Co.

"This is the third strike," said Steven Nissen, chairman of cardiovascular medicine at the Cleveland Clinic. "The studies are telling us that it doesn't appear to produce benefits. This is a drug used by millions of Americans, a very big seller, in a health-care system where costs are a major issue. And the question has to be, is this the right approach?"

Vytorin and Zetia are among the most popular prescription drugs. Last year, physicians in the United States wrote a total of more than 29 million prescriptions for them, and worldwide sales totaled $4.56 billion, according to Merck.

Although the drugs have been shown to reduce cholesterol, there is no evidence that they prevent heart attacks, strokes and other cardiovascular problems.

Top Merck executives are vigorously defending their drugs and have dismissed the new research as limited.

"I don't think a clinician or a doctor or a patient should use this as the basis for any decision-making whatsoever," said Richard Pasternak, vice president of Merck research laboratories. "I worry that people might unnecessarily come off a drug that is approved and accepted."

He and other critics said the study appearing Monday involved just 200 patients, was ended early, and examined what is known as a surrogate marker -- the amount of plaque on artery walls -- rather than evaluating the rate of heart attacks and stroke.

Because plaque can clog arteries and restrict blood flow to the heart and brain, cardiologists view plaque as a good indication for the risk of heart attack and stroke.

The study has been highly anticipated by the medical community and financial analysts, and is the buzz at the annual meeting of the American Heart Association, which began Sunday in Orlando.

Introduced in 2002 and 2004 amid heavy direct-to-consumer marketing, Zetia and Vytorin became blockbusters for Merck and Schering-Plough, which had collaborated on their development. The companies recently merged.

But new research has placed the drugs under greater scrutiny and the number of written prescriptions has been slipping, although together they still represent big business for Merck.

Last year, a study released by Merck showed that Zetia did not reduce plaque in arteries compared with patients taking only statins, which are much less expensive and available in generic form. Although released in January, the study had been completed in 2006, prompting a class-action lawsuit alleging that Merck intentionally withheld unfavorable results of a clinical trial. The company paid $41.5 million in August to settle the claims.

Another study published last year showed a potential increase in cancer among patients taking Zetia and Vytorin, compared with those taking only statins.

Taken as a whole, the new research is unnerving, said Harlan Krumholz, a Yale University cardiologist. "The accumulating evidence isn't giving you any confidence," he said. "This is a very expensive drug being used without any strong evidence that it's benefiting patients." Zetia and Vytorin should be "drugs of last resort, if used at all," Krumholz said. "And anyone who uses it should make sure patients are informed that they're taking a gamble."

Statins, such as Lipitor, have long been used to lower cholesterol and reduce cardiovascular disease. They inhibit the production of LDL, or low-density lipoprotein, often called "bad" cholesterol, which can lead to plaque buildup in arteries.

Zetia, the brand name for ezetimibe, uses a different mechanism. It blocks the absorption of cholesterol from food in the intestines. It has been shown by Merck to lower LDL by 18 percent on average. It is designed for patients who cannot tolerate statins, or for whom high-dose statins are not working.

Vytorin is Zetia combined with a statin, simvastatin, in one pill.

The study released Monday followed about 200 patients who were already taking statins. Some were also given Niaspan, a modified form of Vitamin B, or niacin. The rest took Zetia. Researchers took images of the artery leading to the brain to measure the thickness of the artery walls over 14 months.

The patients who took Niaspan had less plaque in their arteries and also had higher levels of high-density lipoprotein or HDL. Known as "good" cholesterol, HDL is believed to remove cholesterol from the arteries and carry it back to the liver, where it is passes from the body.

The patients who took Zetia had more plaque in their arteries but lower levels of LDL. They also had more heart attacks, strokes and other cardiovascular problems than the patients taking niacin. Merck President Peter Kim said the fact that Zetia lowers LDL cholesterol makes it valuable. "It's very well established that lowering LDL saves lives," he said.

Roger S. Blumenthal, a cardiologist at Johns Hopkins, criticized the new study in an editorial also published Monday in the New England Journal of Medicine. Blumenthal, who has been a paid speaker for Merck, noted that the new study was halted early, which meant results from 40 percent of the participants were not included in the final analysis.

The study's author, Allen J. Taylor of Walter Reed Army Medical Center and Washington Hospital Center, said the trial ended early because the results were quickly apparent. "It couldn't be more clear," Taylor said. "It would have been unreasonable to continue the experiment because the trial had met its objective -- niacin is superior to ezetimibe."

Kim said any conclusions about Zetia and Vytorin should wait until Merck completes a large-scale clinical trial. It involves 15,000 patients and is not expected to yield results until at least 2012.

Mad Science? Growing Meat Without Animals

By Charles Q. Choi, Special to LiveScience
posted: 19 November 2009 08:03 am ET

Winston Churchill once predicted that it would be possible to grow chicken breasts and wings more efficiently without having to keep an actual chicken. And in fact scientists have since figured out how to grow tiny nuggets of lab meat and say it will one day be possible to produce steaks in vats, sans any livestock.

Pork chops or burgers cultivated in labs could eliminate contamination problems that regularly generate headlines these days, as well as address environmental concerns that come with industrial livestock farms.

However, such research opens up strange and perhaps even disturbing possibilities once considered only the realm of science fiction. After all, who knows what kind of meat people might want to grow to eat?

Advantages touted

Increasingly, bioengineers are growing nerve, heart and other tissues in labs. Recently, scientists even reported developing artificial penis tissue in rabbits. Although such research is meant to help treat patients, biomedical engineer Mark Post at Maastricht University in the Netherlands and his colleagues suggest it could also help feed the rising demand for meat worldwide.

The researchers noted that growing skeletal muscle in labs — the kind people typically think of as the meat they eat — could help tackle a number of problems:

* Avoiding animal suffering by reducing the farming and killing of livestock.
* Dramatically cutting down on food-borne ailments such as mad cow disease and salmonella or germs such as swine flu, by monitoring the growth of meat in labs.
* Livestock currently take up 70 percent of all agricultural land, corresponding to 30 percent of the world's land surface, according to the Food and Agriculture Organization (FAO) of the United Nations. Labs would presumably require much less space.
* Livestock generate 18 percent of greenhouse gas emissions, more than all of the vehicles on Earth, the FAO added. Since the animals themselves are mostly responsible for these gases, reducing livestock numbers could help alleviate global warming.

Need to scale up

Stem cells are considered the most promising source for such meat, retaining as they do the capacity to transform into the required tissues, and the scientists pointed to satellite cells, which are the natural muscle stem cells responsible for regeneration and repair in adults. Embryonic stem cells could also be used, but they are obviously plagued by ethical concerns, and they could grow into tissues besides the desired muscles.

To grow meat in labs from satellite cells, the researchers suggested current tissue-engineering techniques, where stem cells are often embedded in synthetic three-dimensional biodegradable matrixes that can present the chemical and physical environments that cells need to develop properly. Other key factors would involve electrically stimulating and mechanically stretching the muscles to exercise them, helping them mature properly, and perhaps growing other cells alongside the satellite cells to provide necessary molecular cues.

So far past scientists have grown only small nuggets of skeletal muscle, about half the size of a thumbnail. Such tidbits could be used in sauces or pizzas, Post and colleagues explained recently in the online edition of the journal Trends in Food Science & Technology, but creating a steak would demand larger-scale production.

Dark thoughts

The expectation is that if such meat is ever made, scientists will opt for beef, pork, chicken or fish. However, science fiction has long toyed with the darker possibilities that cloned meat presents.

In Warren Ellis and Darick Robertson's epic sci-fi satire "Transmetropolitan," supermarkets and fast food joints sell dolphin, manatee, whale, baby seal, monkey and reindeer, while the Long Pig franchise sells "cloned human meat at prices you like."

"In principle, we could harvest the meat progenitor cells from fresh human cadavers and grow meat from them," Post said. "Once taken out of its disease and animalistic, cannibalistic context — you are not killing fellow citizens for it, they are already dead — there is no reason why not."

Of course, there are many potential objections that people could have to growing beef, chicken or pork in the lab, much less more disturbing meats. Still, Post suggests that marketing could overcome such hurdles.

"If every package of naturally grown meat by law should have the text, 'Beware, animals have been killed for this product,' I can imagine a gradual cultural shift," Post said. "Of course, we still have a long way to go to make a product that is even remotely competitive with current products."

Mothers' exposure to chemicals may affect boys

By Juliet Eilperin
Washington Post Staff Writer
Tuesday, November 24, 2009

Elevated levels of two plastic-softening chemicals in pregnant women's urine are linked to less-masculine play behavior by their sons several years later, according to a study published last week in the International Journal of Andrology.

Phthalates (THAL-ates), which are used in everything from vinyl floors to plastic tubing and soaps and lotions, are pervasive in the environment and have increasingly become associated with changes in development of the male brain as well as with genital defects, metabolic abnormalities and reduced testosterone in babies and adults.

A team of U.S. and British researchers posed a standard play questionnaire to the parents of 145 preschool-age children. Then they ranked the types of play on a scale from most masculine (such as play fighting or using trucks) to most feminine. An effect was identified among the sons of women with higher concentrations of di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) in their prenatal urine: On average, those boys scored 8 percent further away from the masculine end of the scale than other boys.

The presence of these chemicals, which are in polyvinyl chloride (PVC) tubing and often make it into the human body through consumption of processed food, was not associated with any differences in girls' play behavior.


"This is enough information to ask manufacturers to let people know when they're exposed, so they can make choices," said the study's lead author, Shanna Swan, a professor of obstetrics and gynecology at the University of Rochester Medical Center. "I don't think it's enough to ban these things." She said the study needs to be replicated at a larger scale in a different population.

Elizabeth Grossman, author of the new book "Chasing Molecules: Poisonous Products, Human Health, and the Promise of Green Chemistry," said when it comes to public disclosure, "we're not there yet" in terms of phthalates.

"The information that's out there and available on PVC products is very confusing and incomplete," Grossman said. For example, she said, she had found a yoga mat advertised as being made of "phthalate-free" PVC -- a contradiction in terms.

Vaccine system remains antiquated

By Rob Stein
Washington Post Staff Writer
Tuesday, November 24, 2009

After a lethal bird flu virus emerged in Asia, U.S. officials launched an intense effort to build new defenses against a pandemic, including replacing an antiquated vaccine system, which depends on millions of chicken eggs.

But six years later, as Americans from Washington to California line up to get inoculated against the swine flu, the slow progress toward developing better ways to make a vaccine has become glaringly obvious.

This lag and the shortage of H1N1 vaccine have focused attention on the status of government efforts to develop state-of-the-art techniques to make flu and other vaccines, including those needed to protect against bioterrorism, and the nation's dependence on a process that is notoriously slow and unreliable.

Several new technologies are showing promise. Spurred by $487 million in federal funding, a sprawling new vaccine factory is opening in North Carolina Tuesday that will produce shots using dog cells instead of chicken eggs. A Connecticut biotech company has also applied to sell a vaccine employing a radically different approach involving a genetically engineered virus infecting insect cells -- a strategy a Rockville firm is testing to inoculate people against the swine flu in Mexico. Dozens of other high-tech approaches are also moving through the pipeline.

While several companies are trying to ready their new techniques in case the H1N1 pandemic worsens, most of these remain years away from contributing significantly to the world's capacity to respond to a deadly new pathogen.

"If this pandemic had come next year, we might have had some of these vaccines licensed and we would have been able to use them -- our investments might have borne fruit," said Robin Robinson, of the Health and Human Services Department. "But unfortunately they didn't help us this year. Others still have a ways to go."

The most immediate solution to the vaccine shortage would be adjuvants -- compounds that boost the immune response, allowing limited stock to be stretched into more doses. H1N1 vaccine with adjuvants is available in Europe, Asia, the Middle East, Canada and Mexico. The United States has decided against using adjuvants because the Food and Drug Administration has not fully reviewed them. Officials worried that a new product would make people even more nervous about the inoculation.

'Fragile technology'

For decades, flu vaccine has been produced by identifying which strains of flu virus were most likely to be circulating, tinkering with microbes in the laboratory to create "seed" virus, injecting that virus through the fragile shells of newly fertilized chicken eggs and waiting several days for the microbes to grow.

The process takes six to nine months and is highly unpredictable. The H1N1 seed virus initially grew inside the eggs at only about a third to a quarter of the expected rate, accounting for most of the lag in production.

"It's a time-honored but nonetheless fragile technology," said Anthony S. Fauci of the National Institute of Allergy and Infectious Diseases.

In addition, the process relies on having access to millions of eggs -- each egg typically produces one to three doses of vaccine. If the next pandemic is caused by a virus that kills birds, like the H5N1 avian flu virus that emerged in 1997 in Hong Kong and reemerged in 2003, any process dependent on chickens would be vulnerable.

Pharmaceutical companies, however, have had little incentive to invest in new technologies. Flu vaccine is relatively cheap and the market is capricious -- millions of doses often end up being discarded because of tepid demand. The long, expensive process of getting new vaccines approved creates another disincentive.

"We're behind the curve in embracing new technology because we're exceedingly cautious," said Scott Gottlieb, a former deputy FDA commissioner now at the American Enterprise Institute.

But in 2006 the federal government awarded $1.3 billion to six companies to develop flu vaccines using cells to grow the virus instead of eggs, although three recipients have dropped out or stalled.

"You just take the cells out of the freezer right away and ramp up production," said Andrin Oswald of Novartis. The Swiss company already makes flu vaccine using dog kidney cells for Europe and Japan at a factory in Germany; on Tuesday, it will cut the ribbon on a massive new facility in Holly Springs, N.C., that will eventually be able to produce 150 million doses of vaccine in six months for the United States. But the factory will not be ready to start making vaccine until 2011 at the earliest.

Baxter International won approval last month to sell an H1N1 vaccine in Europe that uses a decades-old line of African green monkey kidney cells, and it is working on a vaccine for the United States.

But the Deerfield, Ill., company has not said yet whether it will build a U.S. factory, which the federal government required in the contracts. Britain's GlaxoSmithKline spent $300 million on a facility in Marietta, Pa., but it remains in the earliest stages of development.

Sanofi Pasteur shelved its efforts after studies indicated the cell-based vaccine it was developing was not superior to the traditional vaccine it makes at its new $200 million facility in Swiftwater, Pa. Solvay dropped out after deciding to expand its production capacity in The Netherlands instead of building a U.S. factory. MedImmune of Gaithersburg put its program on hold after the FDA demanded additional studies that the company argued were unnecessary.

Even if cell-based vaccines eventually make it to the U.S. market, no one sees them as a long-term solution. They may shave weeks off the production time, which this year would have made a significant difference. But they still require lengthy production schedules for purification and testing.

Latest approaches

More promising is a new generation of vaccines that do not depend on growing the virus. Instead, they exploit the latest in genetic technologies to use the viral DNA to quickly churn out key proteins to elicit a protective immune response.

Protein Sciences of Meriden, Conn., has applied to the FDA for approval to sell a vaccine made by genetically engineering flu genes into a worm virus, which then infects cells from caterpillar ovaries to produce the necessary proteins to make vaccine.

"The other approaches are evolutionary. Ours is revolutionary," said Daniel D. Adams, the company's chief executive.

After being turned down for government funding for years, the company last spring won a five-year, $147 million contract from HHS to develop the vaccine. An FDA advisory panel Thursday voted that the vaccine appeared to be effective in adults but more studies were needed, including to make sure it worked in children and was safe.

Novavax of Rockville is testing a similar vaccine on 4,000 people in Mexico in the hopes of getting an H1N1 vaccine approved by Mexican regulators.

VaxInnate of Cranbury, N.J., for example, produced an experimental H1N1 vaccine using genetically engineered E.coli bacteria, and Vical of San Diego just won a $1.25 million contract from the Navy to develop an H1N1 vaccine that involves injecting DNA sequences from the virus directly into people.

But these remain probably years away from producing a marketable vaccine, and given the skittishness of many Americans about the traditional shots and even the newer nasal spray, it remains unclear how many would feel comfortable with vaccines produced using insect cells, bacteria, animal kidney cells or other new approaches.

"It will be a uphill road in convincing people that it's safe and effective and represents an advance," said Gregory Poland, a flu vaccine expert at the Mayo Clinic.

Many experts say that while these approaches potentially offer a much quicker and easier way to produce large amounts of vaccine, they do not represent the ultimate solution.

That goal, they say, would be to produce a "universal vaccine," which would not have to be altered each year to match whatever strain of the virus is circulating.

"That would be the home run of flu vaccines," said John Treanor, a University of Rochester flu vaccine expert.

Other experts said the federal government should also take steps to guarantee vaccine makers that it would buy any excess vaccine and subsidize excess vaccine production capacity.

"Imagine if this was 1918-like influenza and lots more people were dying and we had no vaccine. We would see the world coming to a screeching halt," said Michael T. Osterholm, director of the University of Minnesota's Center for Infectious Disease Research and Policy. "This should be a wake-up call that we need to have an intervention that allows us to stay in control. Right now the virus is in charge."

Childbirth May Slow Progression of Multiple Sclerosis

By Jennifer Thomas
HealthDay Reporter by Jennifer Thomas
healthday Reporter – Tue Nov 24, 11:48 pm ET

TUESDAY, Nov. 24 (HealthDay News) -- Having children may slow the progression of multiple sclerosis, new research suggests.

Belgian researchers followed 330 women who had experienced their first MS symptoms between the ages of 22 and 38.

Women who had given birth to at least one child were 34 percent less likely to have the disease progress to a stage in which they needed walking assistance, such as a cane or brace, than women without children.

While having a baby either before or after the onset of MS symptoms seemed to help, women who had a child after they began experiencing MS symptoms were even better off. During the study, women with MS symptoms who'd had a baby were 39 percent less likely to have their disease progress to the point of needing walking assistance. In the study, women had the disease for an average of 18 years.
"Women with MS who have children seem to have a more benign MS course than those who don't," said study author Marie D'hooghe, of the department of neurology at Nationaal MS Centrum in Melsbroek, Belgium.

The research appears in the Nov. 24 online issue of the Journal of Neurology, Neurosurgery & Psychiatry.

Multiple sclerosis is an autoimmune disease in which the body's own defense system attacks myelin, or the protective fatty substance that surrounds nerve fibers in the central nervous system, according to the National Multiple Sclerosis Society. The damage causes a disruption to nerve signals traveling to and from the brain, which causes the numbness, walking problems, blurry vision and fatigue.

About 85 percent of those with MS start with a relapsing-remitting course, in which attacks are followed by partial or total recovery, according to the study. More than half go on to develop a more progressive form of the disease, in which symptoms worsen over time and there are fewer, shorter periods without symptoms. Eventually, the disease can lead to loss of vision and paralysis.

Women are twice as likely to develop MS as men, though women tend to have less severe cases than men, according to the study.

About three-quarters of the women in the study had children. The researchers measured the time it took for women to reach level 6 on the Expanded Disability Status Scale (EDSS), a rating system used by doctors to describe symptoms, with level 1 being the least severe and 10 being death due to MS. Level 6 is defined as needing a cane, crutch or brace to walk.

Women who did not have children took an average of 13 to 15 years to progress to EDSS 6, while women who had children took an average of 22 to 23 years to reach that stage, the researchers found.

"Having one or more children does seem to be beneficial," said Patricia O'Looney, director of biomedical research for the National Multiple Sclerosis Society. "But we don't know enough about the patient demographics to really draw some major conclusions."

Among the unknowns are the treatments the women in the study were getting for MS or if perhaps the women who decided to have children were feeling better and having fewer symptoms.

Though much remains to be learned about the role of pregnancy in MS, a possible reason why it may help slow the progression of the disease is that during pregnancy, the immune system is "downregulated," in part to prevent the mother's body from rejecting the fetus, O'Looney explained. Suppressing the immune system may also help to control MS, O'Looney noted.

Treatments for MS, such as interferon beta-1a and -1b, work by suppressing the immune system.

A second possibility for why childbirth might help delay the progression of MS is that during pregnancy, estrogen levels rise. Previous research has suggested estrogen may help protect from MS by stimulating the cells that make myelin. The MS Society is currently funding a clinical trial in which women with MS are given estriol, a form of estrogen, along with standard MS treatments.

"The sex hormones do seem to have some neuroprotective role, though we are not quite sure how," O'Looney said.

Still, O'Looney stressed that women should not interpret the results as reason to have a baby to delay the progression of the disease, or blame themselves if they decided not to have children.

"We still don't know a lot about the great variability of MS -- why does one person become more progressive while another follows a more benign course," O'Looney said. "What's certain is that one should not conclude it's based on whether or not you have a child. There are so many other factors, including possibly genetic factors, that determine that."

30 November 2009

Sounds During Sleep Aid Memory, Study Finds

Science has never given much credence to claims that you can learn Chinese or French by having the instruction CDs play while you sleep. If any learning happens that way, most scientists say, the language lesson is probably waking the sleeper up, not causing nouns and verbs to seep into a sound-asleep mind.

But a new study about a different kind of audio approach during sleep gives insight into how the sleeping brain works, and may eventually come in handy to people studying a language, cramming for a test or memorizing lines in a play.

Scientists at Northwestern University reported that playing specific sounds while people slept helped them remember more of what they had learned before they fell sleep, to the point where memories of individual facts were enhanced.

In a study published online Thursday by the journal Science, researchers taught people to move 50 pictures to their correct locations on a computer screen. Each picture was accompanied by a related sound, like a meow for a cat and whirring for a helicopter.

Then, 12 subjects took a nap, during which 25 of the sounds were played along with white noise. When they awoke, none realized that the sounds had been played or could guess which ones had been used. Yet almost all remembered more precisely the computer locations of the pictures associated with the 25 sounds that had been played while they slept, doing less well placing the other 25 pictures.

“We were able to cue people to specific information they had learned,” said Ken A. Paller, a cognitive neuroscientist at Northwestern and co-author of the study. “The thinking is that during sleep, memory consolidation is going on and that rehearsal is a good way to strengthen memories.

“We showed that you can get information in during sleep using the auditory system and that you can cue that rehearsal by providing sounds specific to each episode of learning.”

The study adds a dimension to a theory that sleep allows the brain to process and consolidate memories.

A 2007 study found that people who were given whiffs of rose scent as they learned a task remembered the task better when they also inhaled rose scent while sleeping. But the new research suggests that individual memories can be explicitly singled out for strengthening.

“We haven’t before been able to manipulate very specific memories,” said Matthew P. Walker, a neuroscientist at the University of California, Berkeley, who was not involved in the study.

“If you can experimentally amplify the memory-reinforcing process by forcing those sounds back into the brain while we’re asleep,” Dr. Walker said, it “may actually give us some clues as to what that mechanism is.”

Robert Stickgold, a cognitive neuroscientist at Harvard also not involved in the study, noted that the researchers did not play literal phrases recapping the memory, like “the cat is in the lower left,” but instead sound cues associated with a picture and a spatial task. The sounds made sense, too — the meow did not accompany the picture of dynamite, for example.

“It’s not really that you reminded them of what they needed to know,” Dr. Stickgold said, “but rather you reminded them of a larger memory that they needed to know.”

Not every scientist who studies sleep was impressed.

Robert P. Vertes, a neuroscience professor at Florida Atlantic University, said the results showed “such a minor effect that it’s not significant,” adding that the effect was even less significant because other study subjects who remained awake showed similarly better recall with sound cues.

The authors said more research was needed, but added that while awake people would be expected to do better with sound cues, the study was significant because it suggested that people could be coached during sleep.

Sara C. Mednick, an assistant professor of psychiatry at the University of California, San Diego, who was not involved in the study, was intrigued that the sleeping subjects appeared to show slight electrical shifts in their brain waves shortly after cues were played, suggesting that the brain replayed “prior experiences.”

The authors said they were interested in how long memory-enhancement was retained after waking and whether “this kind of thing will show up with overnight sleep,” said John D. Rudoy, a co-author and doctoral student at Northwestern.

The subjects napped 90 minutes or less, long enough to experience slow-wave or deep sleep but not REM sleep. Some scientists believe that in slow-wave sleep the brain reinforces factual memories, while in REM sleep the brain sorts and organizes memories.

The authors and other experts said the study’s primary contribution was helping to understand the brain’s memory-making process and reinforcing, as Dr. Walker put it, “how important it is to get a good eight hours.”

But Dr. Paller said he was exploring whether auditory cues could help reinforce cognitive behavioral therapy for people with depression or anxiety. And in other areas, he said, the method probably could not teach information, but reinforce something already learned.

“One of our speculations is that SAT scores could be improved,” he said.

It might help “a football player trying to learn a playbook,” Dr. Paller added. “Even remembering people’s names.”