Cold meds send 7000 kids to hospitals
Mon, 28 Jan 2008 22:42:07 GMTBy MIKE STOBBE, AP Medical Writer
ATLANTA - Cough and cold medicines send about 7,000 children to hospital emergency rooms each year, the U.S. government said Monday in its first national estimate of the problem.
About two-thirds of the cases were children who took the medicines unsupervised. However, about one-quarter involved cases in which parents gave the proper dosage and an allergic reaction or some other problem developed, the study by the U.S. Centers for Disease Control and Prevention reported.
The study included both over-the-counter and prescription medicines. It comes less than two weeks after the U.S. Food and Drug Administration warned parents that over-the-counter cough and cold medicines are too dangerous for children younger than 2.
The study's findings about the proportion of properly dosed kids who end up in the ER is likely to contribute to FDA discussions about recommendations of cough and cold medicines in the 2-to-6 age group, CDC officials said.
CDC researchers gathered case reports of children 11 and under who had taken cough and cold medications and wound up in 63 hospitals studied in 2004 and 2005. They used that number to come up with the national estimate.
About 1,600 of the estimated 7,100 children are under 2, so the FDA's guidance — if followed — should reduce such ER cases by 23 percent.
Nearly two-thirds of the cases involved kids ages 2 to 5, the CDC found.
"The main message is no medication left in the hands of a 3-year-old is safe," said the CDC's Dr. Melissa Schaefer.
Many of the ER case reports were not specific about symptoms, and the researchers did not follow cases through to conclusion. So they did not know if — or how many — deaths resulted, said Schaefer, an epidemiologist who was the study's lead author.
For the children whose symptoms were reported, allergic reactions like hives and itching were most common, and neurological symptoms like drowsiness and unsteady walking were next, she said.
Most of the medicines involved were liquid combinations of cough and cold treatments, CDC researchers said.
Of the children who reportedly got the right dose of medication, about a third were younger than 2, but more than half were ages 6 to 11, the study found.
Some children suffer side effects from medications, so those results aren't necessarily unexpected, Schaefer said. The FDA will have to balance data like this against the medicines' benefits and other factors, she added.
"What we gave them was a piece of the puzzle," she said.
Parents should not encourage children to take medicine by telling them it's candy, and parents should also avoid taking adult medications in front of kids, CDC officials said.
The study tells a story of the misuse of medications, said Linda Suydam, president of the Consumer Healthcare Products Association, a trade group that represents manufacturers and distributors of over-the-counter medicines.
"These medicines are safe when used as directed, and this government review underscores the importance of educating consumers — especially those with small children — on the safe use and safekeeping of medicine," Suydam said, in a prepared statement.
The study was published online Monday. It will appear in the April issue of Pediatrics, a journal of the American Academy of Pediatrics.
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On the Net:
CDC Web page on medication safety:
http://www.cdc.gov/ncipc/factsheets/poisonprevention.htm
)
New treatment can clear brain clots
Mon, 28 Jan 2008 19:16:57 GMTBy LAURAN NEERGAARD, AP Medical Writer
WASHINGTON - It's a tiny vacuum cleaner for the brain: A new treatment for stroke victims promises to suction out clogged arteries in hopes of stopping the brain attack before it does permanent harm.
Called Penumbra, the newly approved device is the latest in a series of inside-the-artery attempts to boost recovery from stroke, the nation's No. 3 killer.
Now the question is how to determine which patients are good candidates — because, illogical as it may sound, unclogging isn't always the best option.
"Is the patient at a stage of stroke where you're going to hurt them by pulling a clot out, or show benefit?" asks Dr. Walter Koroshetz of the National Institutes of Health. "It's good we have devices. Now we have to learn how to use them."
More than 700,000 Americans suffer a stroke each year, and more than 150,000 of them die. Survivors often face serious disability.
Most strokes occur when blood vessels feeding the brain become blocked, starving delicate brain cells of oxygen until they die. For those, the clot-busting drug TPA can mean the difference between permanent brain injury or recovery — but only if patients receive intravenous TPA within three hours of the first symptoms.
Yet fewer than 5 percent of stroke sufferers get TPA, because they don't get specialized care in time. And of those treated, it only helps about 30 percent, because the clot is often too big or tough for TPA to bust.
Enter Penumbra, an option for patients who miss out on early care — it can be tried up to eight hours after a stroke strikes — or if standard TPA treatment fails.
Specialists thread a tiny tube inside a blood vessel at the groin and push it up the body and into the brain until it reaches the clog. Just like a vacuum cleaner, it sucks up the clot bit by bit to restore blood flow.
For the right patient, Penumbra can produce dramatic help, says Dr. Demetrius Lopes of Chicago's Rush University Medical Center, one of two dozen hospitals that tested the device in 125 severe stroke patients.
He points to 45-year-old Aretha Streeter, whose left side remained paralyzed almost an hour after a big dose of TPA. Lopes scanned her brain and spotted a key artery completely blocked. She agreed to the Penumbra experiment, and started moving as Lopes suctioned out the clot. Streeter was walking the next day, and was left with weakness in her arm instead of paralysis.
The study's full results will be presented next month at a meeting of the American Stroke Association.
But the device vacuumed out clots well enough to earn California-based Penumbra Inc. a surprise speedy approval from the Food and Drug Administration in late December. Rush's Lopes says it caused few serious side effects, and that about 42 percent of successfully treated patients showed significant recovery a month later.
Penumbra isn't the only mechanical clot-buster. Doctors also can try threading a corkscrew-shaped wire called the Merci Retriever through the clot and tugging it out. Researchers also are experimenting with dripping TPA directly on the clot instead of the old IV method, and even beaming the clog with ultrasound waves for an extra jolt.
Here's the rub: Unclogging sometimes does more harm than good in bad strokes, says Koroshetz, deputy director of NIH's National Institute for Neurological Disorders and Stroke.
When the dam is broken and blood rushes into oxygen-deprived brain tissue, it sometimes triggers swelling or a brain hemorrhage. Either can kill.
So treatment is a balancing act: Using brain scans to estimate if the stroke already has killed all the brain tissue it's going to, or if enough still could be salvaged that it's worth the risk of this injury, Koroshetz explains.
"Your ability to succeed with taking the clot out depends on what's going on in the brain," he cautions.
The NIH is funding a 900-patient study comparing standard therapy with different inside-the-artery treatments — the TPA drip, ultrasound, and the Merci Retriever — to tell if and how they should be used. Researchers will decide soon whether to include the new Penumbra device in that study.
What treatment to pick is a doctor's dilemma. For patients, the message is clear: Call 911 as soon as you experience stroke symptoms. They include sudden numbness or weakness, especially on one side; confusion, trouble speaking or walking; or an abrupt terrible headache.
Aretha Streeter didn't realize the worst headache of her life meant a stroke had begun, although her mother had died of a stroke and her sister had survived one. Fortunately she went on to her job as a hospital technician at Rush, so care was just steps away when she slumped over.
"It came and went so fast," Streeter says in amazement at both the speed of the stroke, and its treatment.
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EDITOR's NOTE — Lauran Neergaard covers health and medical issues for The Associated Press in Washington.
Pats Bruschi inspires stroke survivors
Tue, 29 Jan 2008 00:12:40 GMTBy DENNIS WASZAK Jr., AP Sports Writer
SCOTTSDALE, Ariz. - There was a time when Tedy Bruschi was unsure he'd be able to go to a football game again, let alone play in one.
Yet here he is nearly three years later, fully recovered from a stroke and back at the Super Bowl as one of the unbeaten New England Patriots' defensive leaders.
"To help this team get back to this point is a victory for me in itself," the playmaking linebacker said. "I have been working with the American Stroke Association a lot and I know this is a victory for all stroke survivors, as well. I realize the whole group of things I've been able to accomplish."
What he's done has been nothing short of incredible. Bruschi led the Patriots for the second straight season in tackles despite the stroke, which severely impaired his vision and affected his motor skills in February 2005.
"People have talked to me about being an inspiration to them and a lot of stroke survivors talk to me," he said. "I respect that and I am humbled by it. It is something that I am proud to call myself: a stroke survivor."
Just 10 days after helping New England win the Super Bowl, and three days after playing in the Pro Bowl, Bruschi was hospitalized with what was described as a minor stroke. For a 31-year-old football player whose life is all about hitting others with as much force as possible, there was nothing minor about it.
"What he went through was something that very few people really go through, especially at that age," coach Bill Belichick said. "I know there were difficult times for him and times that he didn't ever think he would play football again."
In the weeks afterward, Bruschi had blurred vision and had to relearn how to walk. Even as he left a Boston hospital after being treated, he walked tentatively, his wife, Heidi, beside him and football the furthest thing from his mind.
But after having surgery to repair a hole in his heart, Bruschi vigorously began an improbable comeback.
"I think the one thing they had to watch out for most was that they had to monitor the device in my heart," he said. "What they told me was that I was in a data-free zone. There weren't really tests that I could base myself off of. No one had really done this before."
Bruschi said the battery of tests were nerve-racking and he wondered what would happen if the device dislodged or didn't take correctly.
"My doctors pretty much assured me that it wouldn't, but when you talk to people in the medical profession, words that they use are 'shouldn't' or 'We don't think it will happen,'" he said. "But there is always that slight possibility. Hearing that, that sort of plants a seed in your mind that this could happen, that this could happen or this can possibly happen. I think those tests and seeing those tests are really confidence builders for me, and that it was going to be OK."
Bruschi missed the first six games of the 2005 season before being cleared to return. He then played nine in a row, including a 10-tackle performance against Buffalo in his first game back.
"I'll always remember being on the field and starting next to Tedy that game after he came back from a stroke," fellow linebacker Mike Vrabel recalled. "I'll remember the reaction from the fans and the reaction from the players. It was special."
Bruschi still hears from fans who have been inspired by his courageous comeback or are going through a similar situation.
"Constantly," he said. "Letters, fan mail, e-mails. They tell me their story and how relates to them. My doctors tell me that their patients light up every time they tell somebody, 'This is the same thing Ted Bruschi went through. If he can get back to playing professional football, then you can be a normal, functioning human being also.'"
This Super Bowl has taken on even more special meaning for Bruschi: He attended the University of Arizona. He was a defensive force for the Wildcats, tying the NCAA Division I sacks mark with 52, and was drafted by the Patriots in the third round of the 1996 draft.
Bruschi is preparing for the big game in enemy territory, though, because New England is practicing at Arizona State's football facility.
"It was our archrival in college," he said with a smile. "Being here on campus is ironic to me. When Coach Belichick told us we were practicing at the Arizona State facility, it gave me a little chill. But still, the entire state of Arizona is a state I feel very fond of."
He hopes to leave the Valley of the Sun a champion again.
"We don't consider ourselves invincible. The minute you consider yourself invincible, you're letting your guard down," Bruschi said. "If you think you can't be beat, that's the wrong thought to have. ... The way you do win football games is by doing the things that help you win — preparing during the week and playing good football."
Lead linked to aging in older brains
Sun, 27 Jan 2008 20:28:14 GMTBy MALCOLM RITTER, AP Science Writer
NEW YORK - Could it be that the "natural" mental decline that afflicts many older people is related to how much lead they absorbed decades before?
That's the provocative idea emerging from some recent studies, part of a broader area of new research that suggests some pollutants can cause harm that shows up only years after someone is exposed.
The new work suggests long-ago lead exposure can make an aging person's brain work as if it's five years older than it really is. If that's verified by more research, it means that sharp cuts in environmental lead levels more than 20 years ago didn't stop its widespread effects.
"We're trying to offer a caution that a portion of what has been called normal aging might in fact be due to ubiquitous environmental exposures like lead," says Dr. Brian Schwartz of Johns Hopkins University.
"The fact that it's happening with lead is the first proof of principle that it's possible," said Schwartz, a leader in the study of lead's delayed effects. Other pollutants like mercury and pesticides may do the same thing, he said.
In fact, some recent research does suggest that being exposed to pesticides raises the risk of getting Parkinson's disease a decade or more later. Experts say such studies in mercury are lacking.
The notion of long-delayed effects is familiar; tobacco and asbestos, for example, can lead to cancer. But in recent years, scientists are coming to appreciate that exposure to other pollutants in early life also may promote disease much later on.
"It's an emerging area" for research, said Dr. Philip Landrigan of the Mount Sinai School of Medicine in New York. It certainly makes sense that if a substance destroys brain cells in early life, the brain may cope by drawing on its reserve capacity until it loses still more cells with aging, he said. Only then would symptoms like forgetfulness or tremors appear.
Linda Birnbaum, director of experimental toxicology at the U.S. Environmental Protection Agency, said infant mice exposed to chemicals like PCBs show only very subtle effects in young adulthood. But more dramatic harm in areas like movement and learning appears when they reach old age.
Animal studies also show clear evidence that being exposed to harmful substances in the womb can harm health later on, she said. For example, rodents that encounter PCBs or dioxins before birth are more susceptible to cancer once they grow up.
Studying delayed effects in people is difficult because they generally must be followed for a long time. Research with lead is easier because scientists can measure the amount that has accumulated in the shinbone over decades and get a read on how much lead a person has been exposed to in the past.
Lead in the blood, by contrast, reflects recent exposure. Virtually all Americans have lead in their blood, but the amounts are far lower today than in the past.
The big reason for the drop: the phasing out of lead in gasoline from 1976 to 1991. Because of that and accompanying measures, the average lead level in the blood of American adults fell 30 percent by 1980 and about 80 percent by 1990.
That's a major success story for environmentalists. But work by Schwartz and Dr. Howard Hu of the University of Michigan suggests that the long-term effects of the high-lead era are still being felt.
In 2006, Schwartz and his colleagues published a study of about 1,000 Baltimore residents. They were ages 50 to 70, old enough to have absorbed plenty of lead before it disappeared from gasoline. They probably got their peak doses in the 1960s and 1970s, Schwartz said, mostly by inhaling air pollution from vehicle exhaust and from other sources in the environment.
The researchers estimated each person's lifetime dose by scanning their shinbones for lead. Then they gave each one a battery of mental ability tests.
In brief, the scientists found that the higher the lifetime lead dose, the poorer the performance across a wide variety of mental functions, like verbal and visual memory and language ability. From low to high dose, the difference in mental functioning was about the equivalent of aging by two to six years.
"We think that's a large effect," Schwartz said.
Hu and his colleagues took a slightly different approach in a 2004 study of 466 men with an average age of 67. Those men took a mental-ability test twice, about four years apart on average. Those with the highest bone lead levels showed more decline between exams than those with smaller levels, with the effect of the lead equal to about five years of aging.
Nobody is claiming that lead is the sole cause of age-related mental decline, but it appears to be one of several factors involved, Hu stressed.
If so, it would join such possible influences as high blood pressure, diabetes, stroke, emotional stress and maybe education level, said Bradley Wise of the National Institute on Aging. Nobody knows exactly what causes mental decline with age, he said.
Although the studies by Hu and Schwartz suggest lead is involved, Wise and others say they don't prove the link.
"I think many things impact how we age, but I think right now it's maybe premature to be giving lead a huge role in our age-related cognitive decline," said Dr. Margit L. Bleecker, director of the Center for Occupational and Environmental Neurology in Baltimore. Still, she called the lead hypothesis "a very interesting idea" deserving more study.
Others were more impressed.
"The new evidence from these studies should concern people" said epidemiologist Andrew Rowland of the University of New Mexico. "These two research groups are finding adverse effects on the aging brain at low levels of lead exposure. More work needs to be done, but these studies are raising important questions."
In any case, scientists still face some basic mysteries about the delayed effects of lead. For example, when does it actually harm the brain? Does a high level in the shinbone merely identify those who were the most harmed by chronic exposure decades ago? Or does lead in the bone continue to do its dirty work over a lifetime, leaching into the bloodstream and continuously hammering the brain?
"I think that both things are happening," Schwartz said, though he suspects most of the damage occurred in the past, during years of higher exposure. Hu's suspicions are similar.
Just how lead impairs brainpower is still a mystery. And so is the question of whether anything can be done to help people who have absorbed a lot of lead over a lifetime.
A medical procedure called chelation can remove lead from the body, but it wouldn't help in this case, said experts, who had few suggestions.
For younger people, prevention is a clearer strategy, Hu said. He called for tougher federal standards on lead exposure in the workplace.
And plenty of low-income neighborhoods could use a strong effort to remove lead from old houses, many of which still have lead paint, Rowland said. "It's there on the walls, it's on the radiators, it's underneath the top layers of paint. In places where the paint is crumbling, there's still exposure going on," he said.
Yet another question: Who really has to worry about long-ago lead affecting their brainpower? What about people born after the high lead levels of the 1970s were history?
Schwartz noted that most Americans younger than 30 have gotten much less lead from the environment than the men in his study did. And Hu hopes that the lead effect will peter out in the future.
However, Hu points out that there's still lead in the environment, and exposure remains especially high in many developing countries. And citing evidence that lead can cross the placenta, he says women who grew up in the 1970s might dose their fetuses with the metal.
"Kids who grew up in the 21st century have a lot less to worry about" than their elders, Hu said. But "it's hard for me to be totally optimistic the current generation is completely scot-free."
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On the Net:
Lead information: http://www.epa.gov/lead/index.html
EU health chief uses food labels to fight obesity
Mon, 28 Jan 2008 19:05:11 GMTBy Darren Ennis
BRUSSELS - The European Union's health chief wants to introduce tougher food labeling rules to combat the growing problem of obesity across Europe, but is facing stiff political and industrial opposition.
EU Health Commissioner Markos Kyprianou is due to unveil plans on Wednesday that would require food and drink companies to shake up labeling procedures and detail energy, sugar, salt and fat contents on the front of the packages they produce.
In an interview with Reuters last year, Kyprianou described obesity as "the greatest health threat facing the EU."
"General labeling ... and nutrition labeling is an established way for providing information to consumers to support health conscious food choices," reads the plan's latest draft, obtained by Reuters.
"labeling can be strengthened as a means to support a consumers' ability to choose a balanced diet," it says.
According to the World Health Organization, obesity has more than trebled in most EU countries since the 1980s with the number of obese or overweight children in the bloc rising from 14 million in 2005 to 22 million in 2007.
But Kyprianou is under intense industry pressure, notably from the alcohol sector -- and also some EU governments -- to water down his proposals before a key vote on the blueprint at a meeting of the 27-strong European Commission on Wednesday.
INDUSTRY ANGRY
The Confederation of Food and Drink Industries , representing companies such as Nestle, Kraft and Coca-Cola, favors a more self-regulatory approach and is especially unhappy with the "front of pack" requirement.
"We believe ... that the provision of information concerning a minimum 5 nutrients on front of pack is too much, and that it falls into the trap of 'too much information kills information,"' CIAA said in a letter sent to Kyprianou.
"Industry would like to remain in a position to take self-regulatory initiatives," said the letter, seen by Reuters.
The draft proposals exempt alcohol from declaring salt, sugar and fats, although do call for mandatory labeling of energy content for alcohol.
But the alcohol lobby want a complete exemption from all the rules and the European Spirits Organization -- which includes Diageo and Pernod Ricard -- is angry at Kyprianou's concession to the wine industry.
"It provides for specific rules to be adopted for beer and spirits whilst it foresees an exception from ingredient list labeling for wine," the draft proposal says.
A senior Commission source said Kyprianou had "a battle on his hands" and "may be forced to compromise on many points."
But an official close to Kyprianou, who has up until now shied away from mandatory rules for industry in his fight against obesity, said the Cypriot commissioner would not yield.
"He is very serious about this and will push very hard on every point. The issue of obesity is non-negotiable as far as he is concerned," the official said.
Don39t stop Brazil Carnival but be careful Lula
Mon, 28 Jan 2008 14:40:48 GMTBy Angus MacSwan
SAO PAULO - As Brazilians get ready for their annual Carnival celebrations, the government is urging them to practice safe sex and avoid drinking too much.
"Everybody has the right to have fun and enjoy themselves but it is important to remember that the next week we have to work and look after our families," President Luiz Inacio Lula da Silva said on Monday.
The government also started handing out millions of free condoms at the weekend as part of its campaign to combat AIDS and other sexually transmitted diseases during Carnival.
Five days of frenzied festivities kick off on Friday, with the biggest parties in Rio de Janeiro, Salvador and Recife.
Latin America's largest country stops work and indulges in a riot of drinking, dancing and parades accompanied by often licentious behavior.
Lula appealed in his weekly radio address for people to be careful during the partying.
"No one needs to drink or do anything more than normal to enjoy themselves," he said.
Lula is known as a gregarious character who himself enjoys a drink. His dour warning appeared to be partly prompted by a rise in deaths and accidents from drunken driving during the Christmas holidays.
The Health Ministry launched its annual safe sex campaign on Sunday under the slogan "Good in bed means wearing a condom."
"We have to let people know the importance of prevention," Health Minister Jose Gomes Temporao said at an event in Rio.
States and municipalities in the world's largest Roman Catholic country will distribute 19.5 million free condoms for Carnival.
An education program will focus on alerting young women to the dangers of unprotected sex and encourage them to demand that their partners wear condoms.
Thousands of bandanas and temporary tattoos with safe sex slogans will also be handed out to revelers in the big cities.
Recife city also plans to distribute morning-after contraceptive pills -- a move that has angered the Roman Catholic Church hierarchy.
The church opposes Brazil's much lauded anti-AIDS campaign on the grounds that it promotes contraception.
Bishop Antonio Augusto Dias Duarte of the National Bishops Conference of Brazil said last week that while the church was not against people having fun in Carnival, the morning-after pill and condom campaign "will only serve to diminish inhibitions and encourage orgiastic behavior."
Pediatricians group wants show canceled
Tue, 29 Jan 2008 00:55:27 GMTBy LINDSEY TANNER, AP Medical Writer
CHICAGO - The nation's largest pediatricians' group on Monday said ABC should cancel the first episode of a new series because it perpetuates the myth that vaccines can cause autism.
ABC's new drama, "Eli Stone," debuts on Thursday. It features British actor Jonny Lee Miller as a prophet-like lawyer who in the opening episode argues in court that a flu vaccine made a child autistic. When it is revealed in court that an executive at the fictional vaccine maker didn't allow his own child to get the shot, jurors side with the family, giving them a huge award.
The show's co-creators say they're not anti-vaccine and would be upset if parents chose not to immunize their children after seeing the show.
But, said Dr. Renee R. Jenkins, president of the influential American Academy of Pediatrics, "A television show that perpetuates the myth that vaccines cause autism is the height of reckless irresponsibility on the part of ABC and its parent company, The Walt Disney Co."
"If parents watch this program and choose to deny their children immunizations, ABC will share in the responsibility for the suffering and deaths that occur as a result. The consequences of a decline in immunization rates could be devastating to the health of our nation's children," Jenkins said in a statement.
Autism is a complex disorder featuring repetitive behaviors and poor social interaction and communication skills. Scientists generally believe that genetics plays a role in causing the disorder; a theory that a mercury-based preservative once widely used in childhood vaccines is to blame has been repeatedly discounted in scientific studies.
The academy released the text of a letter Jenkins wrote on Friday, addressed to Anne Sweeney, president of Disney-ABC Television Group. In the letter, Jenkins writes that many viewers "trust the health information presented on fictional television shows, which influences their decisions about health care. "
Jenkins noted that erroneous reports in the United Kingdom linking the measles vaccine to autism prompted a decline in vaccination and the worst outbreak of measles in two decades.
Greg Berlanti, a co-creator of the show, said the episode is fictional but designed "to participate in what is a national conversation" about a controversial subject. He said the boy who plays the autistic child has autism, but that the show's producers have no connection with advocates involved in the autism debate.
"We would be deeply upset" if parents opted against vaccination because of the episode, Berlanti said.
Marc Guggenheim, who helped create the show, said the first episode shows how a fictional company covered up a study that raised questions about its product, and that the message is really about "the downside of the corporatization of America."
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On the Net:
Academy: http://www.aap.org
ABC: http://www.abc.com
Alzheimer39s Research Target May Be a Dead End
Tue, 29 Jan 2008 00:02:12 GMTBy E.J. Mundell
HealthDay Reporter
SUNDAY, Jan. 27 -- A once-promising pathway for research into preventing and treating Alzheimer's disease may have been derailed by a surprise chemical finding, researchers report.
Scientists in laboratories around the world have been investigating drug candidates called amyloid inhibitors, which many experts believed could keep proteins such as amyloid-beta from sticking together in brain tissue.
This type of "sticky" protein plaque build-up is a hallmark of Alzheimer's disease. It also characterizes brain illnesses such as Huntington's disease and "mad cow" disease.
But the new study, published Jan. 27 in the journal Nature Chemical Biology, may sound an unexpected death knell for amyloid inhibitor research.
In the study, a team of chemists at the University of California, San Francisco, found that these candidate drugs form large, unwieldy clumps themselves, rendering them useless as targeted therapy against amyloid in the brain.
High-tech research in the lab is revealing that typical amyloid inhibitors "seem to act not in the way people expect them to and want them to," explained study senior author Brian Shoichet, professor of pharmaceutical chemistry at UCSF.
Once these drugs aggregate into clumps, "they no longer have the right pharmacology, they won't cross the [brain's] membrane barriers, and they inhibit everything -- any protein will bind with them," he said.
In other words, the drugs lose their ability to migrate to the brain to fight amyloid plaque. They also give up their targeted specificity against amyloid, Shoichet said. "They end up inhibiting everything -- any protein that sees them will be sequestered by them," he said. This molecular clumping process is largely inevitable, Shoichet added.
His advice to neuroscientists investigating these agents as potential Alzheimer's therapies: "They should stop."
Another expert agreed.
David Lynn is a Howard Hughes Institute investigator and professor of biological chemistry at Emory University in Atlanta. "I think that Brian's paper argues that [scientists] have been missing the boat here," he said. "It's not clear that you are ever going to get the concentrations that you need of these agents at the right site to be able to have any therapeutic intervention."
On the level of basic chemistry, attacking Alzheimer's and other protein-clumping diseases by preventing amyloid from concentrating has "always been a long shot," Lynn said. That's because amyloid proteins are incredibly "sticky," chemically speaking.
"To find things that will competitively stick and stop them from assembling is theoretically hard to imagine," Lynn said. It was thought that individual molecules of amyloid inhibitors might do so, but the new finding -- that the molecules inevitably bind together in a more impractical mass -- renders them therapeutically useless.
But other avenues of Alzheimer's research remain promising, Lynn said.
"There are certainly other strategies that have potential," he noted, including antibody-focused strategies aimed at eliminating plaques, or treatments focused on easing the downstream effects of amyloid buildup.
Both scientists stressed that it's still not certain whether protein plaques even cause Alzheimer's and other brain diseases, or whether they are merely byproducts of the disease process. "That's really another open area of research," Shoichet said.
"The problem with these diseases is that it is such a moving target," Lynn said. "And so, different people are looking at different things."
More information
There's much more on Alzheimer's disease at the Alzheimer's Association.
Cancer risk growing in developing world UN agencies
Mon, 28 Jan 2008 19:16:53 GMTGENEVA - Developing countries are facing a growing cancer epidemic and expected to see more than two thirds of new cases worldwide over the next 10 years, UN health officials warned on Monday.
Some 84 million people risk dying from cancer over the next decade, the World Health Organisation and the International Atomic Energy Agency said.
The IAEA, the UN atomic watchdog, is involved in the fight agaist the disease through its Programme of Action for Cancer Therapy division, which shares the organisation's knowledge of radiotherapy techniques with other partners in the field.
PACT head Massud Samiei told journalists that "the cancer epidemic will gather pace in developing countries."
Cancer killed 7.6 million people in 2005, according to WHO statistics, making it the single biggest cause of death, ahead of AIDS, TB and malaria combined.
Samiei said that 70 percent of new cancer cases in the next decade are likely to occur in developing countries, where a lack of training, staff, resources and money mean millions of people do not get the care they need.
In Africa, for example, less than half of the continent's 53 countries offer any form of radiotherapy to cancer patients.
The IAEA estimates that around one billion dollars will be needed to develop radiotherapy and other forms of treatment in developing countries over the next decade.
However, "being diagnosed with cancer should not equal a death sentence," Samiei said.
Effective monitoring can catch a third of cases before they become a health risk, while prompt and efficient treatment can help heal another third of cases, he added.
