In a new study, mice bioengineered to mimic the fading memory of Alzheimer's patients got their memories restored -- either by being placed in stimulating environments or by receiving a drug most commonly used to fight cancer.
While the research remains in an early stage, it "really provides hope for human patients, especially those with dementia," said study senior researcher Li-Huei Tsai, a professor of brain and cognitive sciences at the Massachusetts Institute of Technology's Picower Institute of Learning and Memory.
Her team published its findings April 29 in the online edition of the journal Nature.
Alzheimer's disease is becoming more widespread as the population ages, and five million Americans now suffer from the illness, according to the Alzheimer's Association. By 2050, unless new ways are found to prevent or treat the disease, that total could climb to 16 million.
A gradual but inexorable loss of memory is one of the tragic hallmarks of Alzheimer's disease, but neuroscientists have never been clear as to whether memories are truly lost or simply rendered inaccessible.
According to Tsai, experts have long known that a so-called "enriched" environment can boost learning. But can it also help restore fading powers of recall?
"I don't think anyone has studied this in depth, because there's only so much you can do with humans," Tsai said. "And in terms of animal models, it's been difficult, too."
However, a few years ago her team at MIT made a kind of breakthrough in that regard. They bioengineered a strain of mice that could be induced at any time in their lifespan to mimic the steady loss of brain cells -- called neurons -- that occurs with Alzheimer's and other neurodegenerative illnesses. This steady destruction of neurons can lead to serious memory deficits.
Working with this mouse model, Tsai's group first trained a number of the rodents to perform a number of tasks. They then induced an Alzheimer's-like neuronal loss that depletes memory.
However, mice that were kept in an "enriched" environment -- rooms full of shelves, perches, nesting material, tunnels and (especially) other mice -- were still able to use their memory to find their way through mazes they had learned to navigate weeks before.
In contrast, mice kept in unstimulating surroundings typically got lost and failed to complete tasks. These rodents were seemingly unable to remember tasks they had learned before, including navigating the mazes, the researchers said.
How might stimulating surroundings preserve or boost memory? "Environmental enrichment doesn't seem to be bringing back the lost neurons -- we don't think that's the case," Tsai said. "Rather, we think that environmental enrichment promotes new neurons to grow and synapses to form. We propose that it is actually rewiring the brain."
Similar results were seen when mice with induced memory loss received a new type of drug called a histone deacetylase (HDAC) inhibitor. These agents are already being used as cancer therapy and appear to work at the molecular level to "free up" genes that produce vital growth factors and proteins.
Mice given an HDAC inhibitor had much less trouble finding their way through mazes and performing other tasks that relied on memory, compared to mice that did not receive the drug, Tsai said.
Again, she believes that HDACs may have stimulated genes crucial to learning memory in the rodents' brains. This may have led to the formation of new neural networks that gave these brain-impaired mice renewed access to useful memories.
The HDAC inhibitor finding is "really intriguing," said Dr. Paul Sanberg, director of the Center of Excellence for Aging and Brain Repair at the University of South Florida College of Medicine in Tampa.
"Especially because these drugs are already being used in cancer patients, that means that they are already available clinically, so maybe they could be developed a little faster for Alzheimer's patients," he said.
Still, many questions remain. "Exactly which genes are being increased, and which are needed? I don't think that you can tell from this paper," Sanberg said.
Tsai agreed that more study is necessary before HDACs can be tested in Alzheimer's patients. "Right now, we only show the beneficial effects in animal models. Before proceeding to humans, we really have to know more," she said.
But enriched environments -- involving both mental stimulation and physical activity -- are available to help everyone's memory, right now.
"I think that's so important, and not just for Alzheimer's patients," Tsai said. "I think that all of us should keep busy and engaged. That's definitely very beneficial for everyone."
Sunday, April 29, 2007
Scientists Restore Lost Memory in Alzheimer's-Like Mice
Memory loss caused by brain damage is reversible
Degenerative brain diseases, including Alzheimers, could one day be treated with drugs that can reverse distressing loss of memory, according to a study released Sunday.
The very term "memory loss" could be a misnomer in such cases, suggests the study, published in British journal Nature: that cherished recollection of a first kiss, seemingly destroyed by disease, may have simply been rendered inaccessible by obstructed neural pathways.
In laboratory experiments, mice suffering the type of brain damage which in humans typically leads to dementia -- robbing victims of the ability to remember past events or even to recognize loved ones -- were able to recover memories acquired during earlier conditioning, according to the study carried out by researchers at the Massachusetts Institute of Technology.
Following a period of rehabilitation through mental stimulation, the genetically modified mice successfully performed tasks they had "forgotten" in the wake of damage inflicted on specific neural networks in the brain.
The same regenerative results were also later obtained through a drug treatment.
While there is no guarantee that the same techniques will work in humans, the study does raise "the possibility of recovering long-term memories in patients" ravaged by certain neurological disorders, according to lead author Li-Huei Tsai, who conducted the study with four colleagues.
Neurodegenerative diseases attack those parts of the brain and spinal cord that control bodily movement and process information stored in the form of memories.
When brain cells deteriorate or are destroyed, they are not replaced. Earlier studies have shown, however, that healthy neurons stimulated through mental activity or directly by chemicals can grow stronger and reconfigure themselves.
Tsai's breakthrough in a series of ingenious experiments was to demonstrate that this same process of remodeling can be reparative, unlocking memories rendered inaccessible by diseases causing "significant brain atrophy and neuronal loss."
The researchers began their experiment by selecting genetically modified mice in which a protein linked to neurodegenerative disease, called p25, could be switched "on" or "off" chemically.
Before this brain-damaging protein was activated, the mice demonstrated in two tests that they had learned how to avoid an electric shock, and how to navigate a maze quickly for a food reward.
After the animals were subjected to six-weeks of neurological degeneration, they could no longer perform these tasks. But an intensive, four-week regimen of "environmental enrichment" -- scientific jargon for access to lots of toys and play -- led to a sharp increase in learning ability and memory. Indeed, the mice passed the tests almost as well as control mice.
The researchers were careful to focus on long-term memories, thought to be stored in the cortical network, and not recently learned behavior, which is initially encoded in another part of the brain, the hippocampus.
Tsai and her colleagues had a hunch as to what was going on at a molecular level when the memories were retrieved and devised a further experiment to test it by chemically inhibiting an enzyme -- histone deacetylase (HDAC) -- known to interfere with gene transcription.
The results showed the same beneficial effect as the "environmental enhancement," suggesting that it could be the basis for a pharmaceutical treatment for memory loss.
"Using small molecules that target HDACs in patients with dementia could facilitate access to long-terms memories," the study concludes.
Health Tip: Precautions While Mowing the Lawn
Playing near lawn mowers is dangerous for children and adolescents, and adults can get hurt, too, if they don't take the proper precautions. To prevent lawn mower-related injuries, follow these safety suggestions from the American Academy of Pediatrics:
- Use a mower the comes with safety features, like a control that prevents the mower from moving forward if the handles are released.
- Never let children younger than 16 use a riding mower, and children younger than 12 use a push mower.
- Never allow children to ride on mowers, even with an adult.
- Always wear sturdy, closed-toe shoes while mowing, never sandals or flip flops that leave portions of the feet exposed.
- Clean the yard of things like rocks, sticks, and toys before mowing to prevent injuries from flying objects.
- Don't allow children to be in the yard while mowing.
- Always turn the mower off and let the blades stop completely before reaching around the blades.
- Avoid mowing in reverse.
Change of Season Brings Lawn Mower Warning
Each year in the United States, about 9,400 children are treated for lawn-mower related injuries such as lacerations, fractures and amputations of the fingers, hands, toes, feet and legs, say experts at Johns Hopkins Children's Center.
"The No. 1 advice to parents is: Treat the lawn mower as hazardous equipment, not a toy. You don't let a child play with an electric saw, and that's exactly what a lawn mower is," Carol Gentry, pediatric OR nurse manager, said in a prepared statement.
Of the lawn mower accident cases treated at the Johns Hopkins Children's Center between 2000 and 2005, 95 percent involved amputations that required reattachment or reconstructive surgery.
The Hopkins experts offer tips for preventing mower-related injuries:
Church urges Mexico MDs against abortion
The Roman Catholic Church on Sunday called on doctors in Mexico City not to perform abortions and lamented the city's decision to legalize the procedure in the first 12 weeks of pregnancy.
The church has vowed to continue its anti-abortion campaign even through it is under investigation for possibly violating Mexican laws forbidding the church's participation in politics.
Mexico City officials have said doctors at city-run hospitals cannot refuse to perform abortions based on personal moral objection, but in a letter read at Sunday Mass, Cardinal Norberto Rivera said they could.
"We call on all of those of good conscience not to be responsible for the abominable act," the letter stated. "We remind the doctors, nurses, health care workers and all those affected by this unjust law, that they can invoke their human right to conscientious objection."
Archdiocese spokesman Hugo Valdemar Romero has said doctors and nurses who performed abortions and lawmakers who supported the legalization will be excommunicated.
Mexico City Mayor Marcelo Ebrard, whose leftist Democratic Revolution Party backed the bill approved by city lawmakers last week, said he would not be deterred by the church's statements.
"We are in the 21st century, not the 16th," Ebrard said. "I have a lot of respect for issues of faith. ... But this is a case where the affairs of state reign."
Elsewhere in Mexico, abortion is only allowed in cases of rape, danger to the mother's life or severe fetal defects. The only countries in the region that allow abortion are Cuba and Guyana.
Friday, April 27, 2007
Canadian mice first to be grafted with human leukemia
Canadian scientists said Friday they have grown a human cancer from scratch in a lab mouse for the first time, allowing researchers to examine its progression from start to finish.
The animal model, which researchers have pursued for years, could "translate into more effective therapies," John Dick, the lead author of the study and a senior scientist at Princess Margaret Hospital, told AFP.
"By just studying the tumor at the end, we didn't know how the tumor was created," he said.
This crucial new tool could help scientists "better understand the whole process and more rationally target the critical pathways to eradicate these cells that lie at the heart of the cancer," he said.
The study was published Friday in the journal Science.
Previously, researchers would engineer mice to develop cancer, but it was the animal form of the disease. They could also implant human cancers into mice, but missed how the disease originated.
By inserting just one cancerous gene into human stem cells, Dick and his colleagues were able to seed leukemia in specially bred lab mice.
"We haven't proven it, but we believe this process could be used for other cancers too," Dick said.
The same team of scientists were the first to isolate cancer stem cells in acute myeloid leukemia in 1994.
Imaging Technique Could Help Fight Metastatic Cancers
A new imaging technique that measures diffusion of water through tumors may help guide the treatment of advanced prostate cancer that's spread to the bones, says a study by researchers at the University of Michigan Comprehensive Cancer Center.
This technique, called a functional diffusion map, uses an MRI scan and special software to monitor the movement of water through tumor cells over the course of treatment. As tumor cells die, this diffusion of water increases, the researchers explain.
In the study, the Michigan team tested the technique in mice with metastatic prostate cancer.
Mice that received chemotherapy showed progressive changes over the three weeks of treatment, while mice that did not receive chemotherapy had little or no change in water diffusion.
When the researchers removed the tumors from the mice, they found that the functional diffusion map had accurately measured tumor response to treatment. The study was published in the April 15 issue of Cancer Research.
The findings suggest that the functional diffusion map could provide an early assessment of tumor response to treatment, the scientists said. This could help patients avoid wasting time on a treatment that isn't working before they switch to an alternative therapy.
Currently, there is no way to detect bone tumor response to therapy, study author Brian D. Ross, a professor of radiology and biological chemistry at the U-M Medical School and co-director of the Molecular Imaging Program at the U-M Comprehensive Cancer Center, said in a prepared statement.
About 500,000 people in the United States develop metastatic prostate or breast cancers that spread to the bone, he said.
New diabetes genetic risk factors found
Scientists have found clusters of new gene variants that raise the risk of Type 2 diabetes — and how the researchers did it is as important as what they found.
In one of the largest studies yet of human genetic variability, the scientists tested the DNA of more than 32,000 people in five countries to pin down spots that harbor genetic risk factors for this complicated killer.
This type of research — called a "genome-wide association" study — promises to usher in a new era of genetics. Most breakthroughs so far have come from finding a mutation in a single gene that causes illness. But some of the world's most common killers, such as heart disease and diabetes, are caused by complex interactions among numerous genes and modern lifestyles — and teasing out the genetic culprits until now has been almost impossible.
"We have been for all of the last decade or more looking under the lamppost to try to find those genes ... and lots of times the lamplight was not actually where we wanted it," said Dr. Francis Collins, genetics chief at the
National Institutes of Health, a co-author of the research unveiled Thursday.
This new approach "allows us to light up the whole street, and look what we find."
What? Four previously unknown gene variants that can increase people's risk of Type 2 diabetes, and confirmation that six other genes play a role, too.
The work, by three international research teams that shared their findings, was published online Thursday by the journal Science.
Also Thursday in the journal Nature Genetics, another team led by Iceland researchers reported separately finding one of those same new genes — and that, interestingly, it seems to increase the diabetes risk most in people who aren't obese.
Next, the researchers will have to figure out just what those genes do, in hopes they'll point toward new ways to treat or prevent a disease that affects more than 170 million people worldwide, and rising.
With Type 2 diabetes, the body gradually loses its ability to use insulin, a hormone key for turning blood sugar into insulin. It is a major cause of heart disease, as high blood sugar damages blood vessels, and leads to kidney failure, blindness and amputations.
Obesity and lack of exercise are chief risk factors. But heredity is involved, too: People with an affected parent or sibling are at 3.5 times greater risk of developing diabetes than people from diabetes-free families.
The new work scanned DNA to find patterns of small gene variations known as SNPs (pronounced "snips") more common in diabetics. SNPs can serve as signposts for tracing disease-promoting genes. To be certain the implicated SNPs were involved, the researchers then checked for them in still more volunteers, ultimately testing DNA from 32,500 people in Britain, Finland, Poland, Sweden and the U.S.
The highest-risk variants can increase by 20 percent someone's odds of developing Type 2 diabetes, the teams reported.
Cervical abnormalities common in HIV-infected girls
Sexually active teenage girls infected around the time of birth with HIV, the virus that causes AIDS, are more likely to have cervical infections and abnormal Pap test results, new research shows.
Extensive research has examined the reproductive health outcomes among teenagers who acquire HIV infection through sex, senior investigator Dr. Susan B. Brogly of Harvard School of Public Health in Boston told Reuters.
In contrast, this is the largest cohort study, and the first to publish on rates of genital infections, cervical lesions, and pregnancy among girls who had been living with HIV since birth, she said.
Their results will be published in the June issue of the American Journal of Public Health.
The study involved a total of 638 girls infected with HIV during birth, and who were 13 to 21 years old when they entered a pediatric AIDS study between 2000 and 2005. Brogly and her co-investigators estimate that 174 of the girls were sexually active. More than three-quarters were receiving HIV medication.
Pelvic examinations revealed multiple cases of genital warts. Many of the HIV-infected teenage girls were found to have sexually transmitted diseases, including trichomoniasis, chlamydia, gonorrhea and syphilis.
Of the 101 sexually active girls who had Pap tests, 30 (29.7 percent) had abnormal results at the first examination including lesions that have the potential to become cancerous called squamous intraepithelial lesions or SIL.
"We were surprised at the high rates of SIL that were observed," Brogly said. "It is concerning to find such high rates in young adolescent girls."
She and her colleagues were also taken aback by the finding that "pap smears were so infrequent among these girls identified as sexually active."
Thirty-eight girls became pregnant for the first time while in the study. Seven were pregnant more than once, resulting in 32 pregnancies that ended with live births. Of these, only one newborn was known to be HIV-infected.
The rate of pregnancy is much lower in this cohort than among HIV-uninfected girls of similar ages in the US, the team reports. Brogly attributes the low pregnancy rates to the fact that "some of these girls have severely compromised health and serious illness, making it difficult to become pregnant."
SOURCE: American Journal of Public Health, June 2007.
Health Tip: Using Car Seats
Car seats can protect children in the event of an accident, but only if they are used properly.
Here are some tips on how to make sure you are using your child's car seat correctly, courtesy of the American Academy of Pediatrics:
- Always put your child in a car seat, starting with the baby's first ride home from the hospital.
- Install the car seat in the automobile's back seat, never in the front where there's an airbag.
- Always read the seat's instructions, including how to install it, and how to attach and detach the seat and base.
- Keep the instructions and owner's manual as long as you have the seat, in case you need them.
Health Tip: Precautions While Mowing the Lawn
Playing near lawn mowers is dangerous for children and adolescents, and adults can get hurt, too, if they don't take the proper precautions. To prevent lawn mower-related injuries, follow these safety suggestions from the American Academy of Pediatrics:
- Use a mower the comes with safety features, like a control that prevents the mower from moving forward if the handles are released.
- Never let children younger than 16 use a riding mower, and children younger than 12 use a push mower.
- Never allow children to ride on mowers, even with an adult.
- Always wear sturdy, closed-toe shoes while mowing, never sandals or flip flops that leave portions of the feet exposed.
- Clean the yard of things like rocks, sticks, and toys before mowing to prevent injuries from flying objects.
- Don't allow children to be in the yard while mowing.
- Always turn the mower off and let the blades stop completely before reaching around the blades.
- Avoid mowing in reverse.
Researchers Identify Genes for Childhood Seizures
French scientists studying four generations of a single family have honed in on two genes associated with fever-related seizures in infants and children.
These "febrile" seizures are the most common seizure disorder in children, affecting 2 percent to 5 percent of children by age 6 in the United States. Most children with the disorder experience seizures only once or a few times and suffer no permanent brain damage. Some children with febrile seizures do develop other seizure disorders, such as epilepsy, later in life.
Of the 51 people in the family, 13 had childhood febrile seizures. In all cases, the seizures stopped by age 7, but six of the 13 developed epilepsy later on. The researchers compared the 13 people affected by febrile seizures to 13 other family members who did not have the attacks.
The study found that those who had febrile seizures shared similarities on chromosome 3 and chromosome 18.
The findings are published in the April 24 issue of Neurology.
"Identifying the genes responsible for febrile seizures could improve the understanding, treatment and even prevention of this disorder," study author Dr. Rima Nabbout, of the French Institute for Medical Research in Paris, said in a prepared statement.
Previous studies have identified four other chromosome areas associated with febrile seizures.
Dozens sick after meal at Chinese school
More than 50 children were poisoned by a kindergarten breakfast in central China, state media said Thursday, in the latest case highlighting problems in the country's food supply chain.
Xinhua News Agency said the children were hospitalized after eating breakfast Wednesday at a private kindergarten in Zhengzhou city in Henan province. Thirty had been released and the others remained under observation.
Doctors believe soybean milk given to the children was not boiled properly, Xinhua said.
Mass poisonings are common in China, which has been struggling to improve a dismal food safety record. Manufacturers often mislabel food products or add illegal substances to them. Cooks routinely disregard hygiene rules.
Last week there were three cases in various parts of the country involving about 280 people.
In the latest incident, the person in charge of the private kindergarten and three cooks who prepared the breakfast have been detained by police, Xinhua said.
Vitamin A May Boost Vaccine Effectiveness in Kids
Giving vitamin A supplements to young children may boost their immune system response to tetanus and other types of vaccines, U.S. researchers say.
In regions of the world where vitamin A deficiency is common, preschool-aged children are often given vitamin A supplements along with vaccinations for tetanus and other pathogens, according to background information in the study.
However, whether vitamin A supplementation has an immediate effect on the immune system's response to the vaccine, or whether vitamin A helps immune response to vaccines only later in life, had not been tested, said a team from Pennsylvania State University.
In research with rats, they found that giving vitamin A supplementation to young rats helped improve immune response to tetanus vaccinations at a later age.
If the same is true in young children, the researchers said that "neonatal-age vitamin A supplementation may benefit the vaccine response of children whose post-weaning vitamin A intake is not adequate."
Omega-3 may fight Alzheimer brain changes
A fatty acid found in fish may help thwart the buildup of brain proteins linked to Alzheimer's disease, a study in mice suggests.
In Alzheimer's disease, lesions known as "plaques" and "tangles" form in the brain, due to the abnormal clumping of two proteins called beta-amyloid and tau. The mouse study found that a diet rich in the fatty acid DHA might interfere with this process.
DHA, short for docosahexaenoic acid, is a type of omega-3 fatty acid found mainly in fatty fish like salmon and mackerel, and to a lesser extent in seaweed, eggs, organ meats and DHA-fortified foods.
While the new findings come from studying mice, they complement studies in humans that have linked higher fish intake, as well as higher blood levels of DHA, to a lower risk of Alzheimer's disease.
Such research suggests that the animal findings might well translate to people, Dr. Frank LaFerla, the senior author on the new study, told Reuters Health.
He and his colleagues at the University of California at Irvine report their results in the Journal of Neuroscience. Several co-authors on the study are with Martek Biosciences Corp., a Maryland-based company that makes a DHA product used in a range of infant formulas, foods and supplements.
For their study, the researchers used mice genetically engineered to develop Alzheimer's-like plaques and tangles. At the age of 3 months, the animals were placed on one of four diets.
One diet mimicked the typical American diet, with low amounts of omega-3 fats and far higher levels of omega-6 fats, which are found in various vegetable oils, eggs and meat. The other three diets were rich in omega-3 fatty acids; one was supplemented with DHA only, while the other two had added DHA and omega-6 fats.
After 9 months, the study found, mice on the diet supplemented with DHA alone had lower levels of beta-amyloid and tau in their brain tissue than the animals in the other three groups.
The researchers also discovered that DHA may confer its benefit by lowering levels of an enzyme needed to generate beta-amyloid.
What's needed now, according to LaFerla, are clinical trials involving people with early-stage Alzheimer's to see whether DHA supplements can slow the progression of the disease. Martek has just launched such a study, he said.
SOURCE: Journal of Neuroscience, April 18, 2007.
Depression May Be Early Sign of Parkinson's Disease
In some cases, depression can be an early manifestation of Parkinson's disease, new research suggests.
Researchers at the Harvard School of Public Health compared antidepressant use among more than 1,000 individuals with Parkinson's disease to more than 6,600 age- and gender-matched individuals without the degenerative neurological illness.
They found that people currently on antidepressants had an 80 percent higher risk of developing Parkinson's disease than those who had never taken antidepressants. This was true for both men and women, regardless of age or the class of antidepressant used.
"We think this is not actually the medication that is causing Parkinson's disease. Instead, we think people who are going to get Parkinson's disease get depression first," said study co-author Dr. Alvaro Alonso, a research associate at Harvard. "It's very important not to say that people taking antidepressants have a higher risk of developing Parkinson's disease," he said.
That's because the effect was only apparent in the year prior to disease diagnosis, and because it was true for two different types of medications, tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs), which work via wholly different mechanisms, Alonso explained.
He noted that additional data, not included in the published study, indicated that newer users of antidepressants -- those who had been on the drugs for less than one year -- had a threefold higher risk of developing Parkinson's than people who had never used antidepressants.
Alonso's interpretation: Depressive symptoms could be one of the first manifestations of Parkinson's disease.
The research is scheduled to be presented May 1 at the annual meeting of the American Academy of Neurology, in Boston.
Dr. Rajesh Pahwa, director of the Parkinson Disease and Movement Disorder Center at the University of Kansas Medical Center, in Kansas City, called the observation "interesting."
At the same time, he said, the depression-Parkinson's link is "common knowledge" among neurologists, who have long recognized that depression often occurs alongside Parkinson's disease.
However, primary care physicians and psychiatrists, who may not be aware of the link, "need to pay more attention to this issue," Pahwa said. At-risk individuals who suddenly develop depressive symptoms could in fact be showing the first signs of Parkinson's.
Neurologists could also benefit from these findings, Pahwa added.
"For us, the biggest issue is that we need to pay more attention to depression in Parkinson's disease," Pahwa said. Too often, physicians may view depression as a natural psychological reaction to a Parkinson's diagnosis. However, that may not sometimes be the case, "and we need to treat it more aggressively," he said.
According to Pahwa, Parkinson's disease is a progressive neurodegenerative disorder marked by the loss of dopamine-producing neurons in the brain. Though most commonly associated with motor deficits such as tremors and stiffness, there also are non-motor features, including urinary problems, constipation, insomnia, depression, anxiety, and dementia. There is no laboratory test for Parkinson's, so it must be diagnosed clinically. Nor is there yet any cure for this degenerative disease.
According to the National Parkinson Foundation, 1.5 million Americans currently have the illness, which strikes men and women in roughly equal numbers, usually after the age of 65.
Dr. Giselle Petzinger, a movement disorder specialist at the University of Southern California, said this study is the first to "really suggest" that non-motor features could be early indicators of Parkinson's disease.
"This is pretty convincing data," she said. "Mood probably could be an early manifestation. That's never been shown before."
Petzinger said such early symptoms could enable eventual earlier -- and thus, more effective -- use of neuroprotective medicines, though she noted that no such drug currently exists.
"You want to catch them before they develop motor symptoms," Petzinger said. "That might be a point of no return. Early recognition, that's when you want to capture people."
Program fails to curb falls in older folks
A community-based intervention designed to address multiple factors that put elderly people at increased risk for falling and injuring themselves has proven ineffective. There was no decrease in the number of falls in "at-risk" elderly individuals who completed the program.
Falls are a significant source of illness and death for older adults, Dr. Jane E. Mahoney, of the University of Wisconsin, Madison, and colleagues note in a report
They conducted a randomized, controlled trial to examine the efficacy of an intervention to reduce falls in 344 older adults living in the community. These people were at least 65 years old and had suffered two falls in the previous year, or one fall in the previous 2 years plus injury or balance problems.
In the intervention group, a trained nurse or physical therapist assessed the subjects' fall risk factors during two in-home visits, followed by 11 phone calls each month. The intervention group was also referred to physical therapy or other providers, along with a balanced exercise plan.
Individuals in the control group received the in-home assessment only and were advised to contact their physician about falls.
During follow up, which lasted at least 365 days for 274 participants, there was no significant difference in the risk of falls between the intervention group and the control group. However, the subjects in the intervention group spent fewer days in a nursing home than those in the control group.
SOURCE: Journal of the American Geriatrics Society April 2007.
Exercise May Help Ward Off Parkinson's Disease
New research suggests more evidence of yet another benefit of regular exercise: It could keep Parkinson's disease at bay.
The study doesn't conclusively link exercise to better brain health, but scientists think the connection could be more than a fluke.
"The people who seemed to have a lower risk of disease were engaging in moderate to vigorous activity for two to three hours a week," said study leader Evan Thacker, a research assistant at the Harvard School of Public Health.
Parkinson's disease is a movement disorder that worsens over time and causes a variety of symptoms, including disruptions in movement, as neurons in the brain deteriorate. The cause of the disease is not known, and there is no cure, but drug therapy and surgery can help manage symptoms, according to the Parkinson' Disease Foundation.
An estimated 1.5 million Americans have the disease, and 60,000 new cases are diagnosed each year, according to the foundation. Among famous people who have the condition are the actor Michael J. Fox and former U.S. Attorney General
Janet Reno.
In what Thacker called the largest research project of its kind, researchers looked at the results of a federal cancer study that followed 63,348 men and 79,977 women from 1992 to 2001. Of the participants -- with an average age of 63 -- 413 of them developed Parkinson's disease.
The researchers looked at exercise levels and tried to determine if they affected the rate of Parkinson's disease after adjusting the numbers to reflect the possible influence of factors such as age, gender and smoking.
People who exercised more than 75 percent of their fellow study participants were 20 percent less likely to develop Parkinson's, compared to those who didn't exercise. The risk of the disease was 40 percent lower in those who took part in the highest levels of moderate to vigorous activity, defined as exercise such as jogging, lap swimming, tennis and bicycling, the study found.
However, there's one caveat -- the researchers found no indication that physical activity at age 40 affected the risk of developing Parkinson's.
The results were expected to be reported Monday at the American Academy of Neurology annual meeting, in Boston. As is often the case with research presented at conferences, the study has not been published in a medical journal or gone through the review process that journals require.
A previous study suggested a link between exercise and Parkinson's in men, but not in women, Thacker said. The new findings show both genders may benefit.
Still, he cautioned that his study isn't "the final word."
"We can't prove there was some other factor that caused people to be different," he said. "We can just do the best we can.
Thacker said it's still not clear why exercise might influence the development of Parkinson's. One possibility could be that exercise might affect chemicals in the blood that play a role in the development of the disease, he said.
Researchers at the University of Southern California have found evidence suggesting that exercise changes the way neurons release dopamine -- a crucial brain booster -- in mice, said Michael Jakowec, an assistant professor of neurology at the school.
Disruptions in dopamine production have been linked to Parkinson's.
According to Jakowec, both animal studies and brain imaging in humans will help scientists understand the effects of exercise on the brain.
Does circumcision affect your sex life? Scientists are divided
Two studies have thrown up conflicting evidence as to whether circumcision could harm a man's sex life, New Scientist reports in its next issue.
The question is especially important, given the World Health Organisation's (WHO's) recent endorsement of circumcision in the panoply of weapons to tackle the spread of AIDS.
In a study led by Kimberley Payne of the Riverside Professional Center in Ottawa, 20 circumcised and 20 uncircumcised men watched erotic movies while their penises were measured for sensitivity at two points, using filaments that pressed down with predetermined amounts of pressure.
There was no difference in penile sensation between the two groups, according to their research.
However, a team led by Robert Van Howe of Michigan State University used a similar method, but measuring penile sensitivity at 19 points among 163 circumcised and uncircumcised men.
The five most sensitive points are all in portions of the penis removed by circumcision, especially those in folds exposed as the penis becomes erect, Van Howe believes.
"The glans of the circumcised penis is less sensitive to fine touch than the glans of the uncircumcised penis," his paper says. "(...) Circumcision ablates the most sensitive parts of the penis."
The report appears in next Saturday's issue of the British weekly. Payne's research appears in The Journal of Sexual Medicine, while Van Howe's is published by the British Journal of Urology (BJU) International.
On March 28, the WHO and other agencies in the fight against AIDS gave the stamp of approval to promoting circumcision to help prevent the spread of the human immunodeficiency virus (HIV).
Three studies carried out in southern and eastern Africa found that circumcised men were more than half less likely to be infected by HIV compared to uncircumcised counterparts.
Weighing obesity surgery risks for teens
Seventeen-year-old Amanda Munson gained confidence and energy as she lost 40 of her 296 pounds after weight-loss surgery and her diabetes went into remission.
"People have told me I not only look thinner, but I seem to glow — maybe because I'm so much happier," she said. The 5-foot-5 high school senior from nearby Burlington, Ky., hopes to lose 75 to 100 more pounds.
Munson is the first of 200 teenagers who will be enrolled in a five-year, federally funded study on the benefits and risks of bariatric surgery on adolescents.
Surgery has been effective in treating extreme obesity in adults. Researchers want to find out if adults and adolescents who have the surgery have significantly different health problems and whether there is any benefit to having the operation earlier in life.
The researchers are responding to the growing problem of extreme obesity among the young.
"We know bariatric surgery is effective for weight-loss. We just need to carefully document how teenagers respond," said Dr. Thomas Inge, associate professor of pediatrics and surgery at Cincinnati Children's Hospital Medical Center, which is leading the study.
Recent data from the Centers for Disease Control and Prevention suggest that about 2 million U.S. adolescents may be severely obese and have complications of obesity previously seen only in adults.
While adult weight-loss surgery still is more common, an estimated 2,744 youngsters nationwide had the operations from 1996 through 2003, with the pace tripling between 2000 and 2003, according to an earlier study co-written by Inge.
The doctors expect their research will show that severe obesity in teens is associated with medical and psychosocial problems which may be more effectively treated during adolescence than waiting until adulthood.
"What's fascinating is that teenagers already can have a half-dozen complications of obesity that the surgery within months — if not weeks — can remedy," he said Inge, who has been performing the surgery on adolescents for five years.
The National Institute of Diabetes, Digestive and Kidney Disorders provided more than $5 million last year for the study. Texas Children's Hospital in Houston, Children's Hospital of Alabama in Birmingham and the University of Pittsburgh also are collecting data.
Researchers will compare data before and after surgery on health factors that include cholesterol levels, liver function, cardiosvascular risk and markers for diabetes. Those findings will be compared with data from a similar study on adults who have been obese since adolescence but are only now having the surgery.
Participants must already have been scheduled for the surgery and must have compelling obesity-related complications such as Type 2 diabetes, sleep apnea, high blood pressure or other cardiovascular risk factors.
Information also will be collected on psychological and social effects of the surgery on the teenagers. Severe obesity can lead to low self-esteem, less social interaction with peers and depression.
Kerri Green, director of education for the Weller Health Education Center in Easton, Pa., believes studies are needed to find out if young people can understand the physical, psychological and emotional consequences of bariatric surgery, which she said should be done only for compelling medical reasons.
"We see a lot of what we call the 'Extreme Makeover' phenomenon, where kids see surgery as a quick fix that will make up for poor eating habits and a lack of exercise," she said.
Munson's mother, Barbara Farnsworth, said they exhausted all other options before resorting to surgery.
"It breaks your heart to see your child struggling and becoming so depressed and to hear doctors say she won't see 30 if she doesn't lose weight," Farnsworth said. "This is only a tool, but I now see a future for Amanda that just wasn't there before."
Obesity surgery in teens studied
THE ISSUE: A growing number of teenagers are fighting severe obesity and seeking ways to loss weight, including surgery.
THE QUESTION: Researchers want to know if there are benefits to having weight-loss surgery earlier in life.
THE METHOD: A federally funded study will compare health data from teens having the surgery with data from adults having the surgery.
Wednesday, April 25, 2007
Gentlemen, rate yourselves: cucumber or banana?
Gentlemen please, rate yourselves: are you a cucumber or a banana in bed?
Singapore's Society for Men's Health and a pharmaceutical firm are proposing a four-point scale for erectile dysfunction, allowing men to rate their own hardness with four categories: cucumber, unpeeled banana, peeled banana and tofu (bean curd).
"Men should aim for this," UK sex therapist Victoria Lehmann told a news conference, holding a cucumber.
The scale does not involve any scientific measurement -- patients would merely be asked to assess their own levels of hardness -- and has not been accepted by any medical authorities.
Fish oil may preserve thinking ability in elderly
High blood levels of omega-3 highly unsaturated fatty acids, found in fish oil, may help preserve thinking ability in the elderly, according to the findings of two studies published in the American Journal of Clinical Nutrition.
The results were particularly striking among subjects with high blood pressure or high cholesterol levels.
Accumulating evidence suggests that diets that include omega-3 fatty acids, specifically, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), protect against the development of dementia and Alzheimer's disease, according to a Dutch research team. However, the effect of EPA+DHA consumption on thinking ability, or "cognitive function," has received less scrutiny.
So Dr. Boukje Maria van Gelder, from the National Institute for Public Health and the Environment in Bilthoven, and associates evaluated data for 210 healthy men in the "Zutphen Study," who were 79 to 89 years old in 1990 and had normal mental capacity. Their diets were assessed in 1990, and cognitive function was tested in 1990 and again in 1995.
Subjects who ate fish had a slower decline in cognitive function than subjects who did not eat fish.
The investigators conclude that "fish consumption and EPA+DHA intake are not significantly related to cognitive impairment but are significantly related to cognitive decline."
Van Gelder's team recommends the daily consumption of roughly 400 mg of EPA and DHA, found in fish, meat, eggs, leeks, and cereal products.
In the second study, which involved 2,251 older individuals, Dr. May A. Beydoun, at the University of North Carolina at Chapel Hill, and colleagues showed that high blood levels of EPA and DHA are associated with less decline in verbal ability.
In an accompanying editorial, Dr. William E. Connor and Dr. Sonja L. Connor suggest that EPA has anti-clotting and anti-inflammatory properties that work together to help preserve cognitive function.
SOURCE: American Journal of Clinical Nutrition, April 2007.
Genes May Predict Elderly Blindness Risk
Two genes could determine an older person's vulnerability to an advanced form of age-related macular degeneration (AMD), researchers report.
People who smoked or were overweight faced an even greater risk for the potentially blinding eye condition, the study found.
"The two genetic variants are related and predict to a certain extent which individuals who have earlier-intermediate forms of macular degeneration progress to the advanced form and visual loss," explained the study's lead author, Dr. Johanna M. Seddon, director of the Ophthalmic, Epidemiology and Genetics Service in the department of ophthalmology at Tufts-New England Medical Center and New England Eye Center.
"Genetic variants are part of the way we can differentiate who gets worse, coupled with environmental factors like a high body mass index and smoking," said Seddon, whose team published its results in the April 25 issue of the
Journal of the American Medical Association.
The findings have implications for the prevention of AMD, one expert said.
"They've actually identified specific genes and specific abnormalities in specific genes that prove that macular degeneration has a strong genetic component," said Dr. Robert Cykiert, clinical associate professor of ophthalmology at New York University School of Medicine in New York City. "What this says is if you have someone in your immediate family such as parents or siblings with AMD, then you need to see an ophthalmologist and be carefully followed, because there are things that can be done to prevent progression."
Down the line, there may even be a blood test to detect these genes, further brightening the picture for prevention and early treatment, Cykiert said.
But it's too early to recommend widespread screening, the authors stated.
"Some individuals who progress do not have these genetic variants or have never smoked," Seddon said. "We need to refine this predictive measure, add more genetic variants and maybe even more environmental factors."
Age-related macular degeneration (AMD) involves damage to the inner lining of the eye and can lead to visual impairment and even legal blindness.
"There are several million people who have the earlier-intermediate stages of AMD once they reach the age of 75 or older, but [only] 6 to 8 percent of individuals have advanced disease, so the question is, how do we predict or identify those people who are at higher risk?" Seddon said.
AMD has previously been associated with variations in two genes: CFH and LOC387715. But previous studies exploring this relationship had been cross-sectional in nature, not prospective as the current one is.
For this study, Seddon and her colleagues looked at almost 1,500 white adults aged 55 to 80 with the earlier intermediate signs of macular degeneration. During an average of more than six years of follow-up, 281 individuals progressed to advanced AMD in one or both eyes.
Genotypic analysis revealed that two specific genetic polymorphisms -- CFH Y402H and LOC387715 A69S -- were linked with progression to more advanced AMD.
The risk of progression was 2.6 times higher for those with the CFH variant and 4.1 times higher for those with the LOC387715 variant, after controlling for other factors.
For people who had one of the genotypes, smoking and being overweight increased the risk 19-fold, making a strong argument for lifestyle changes in people who are identified as having the genetic risk factors.
States lag in hospice oversight
A significant number of Medicare hospice programs were not checked by state inspectors for nine years and were long overdue for certification, according to a federal report released Tuesday.
Three states — California, Illinois and Michigan — were furthest behind, accounting for 41 percent of the past-due certifications, according to the report by the inspector general's office of the U.S. Department of Health and Human Services.
Of the hospices surveyed, 46 percent were cited for at least one health deficiency, such as missing or inadequate patient-care plans.
Visits by state surveyors are the main way the federal government tracks the quality of care in hospices that get Medicare funding.
Medicare payments to hospices overdue for inspection averaged $2.7 million each in 2004, the report said.
Hospices give care, including pain management, to people with terminal illnesses. Most care takes place in a dying patient's home, with hospice staff members making regular home visits and being on call to families.
"We've been calling for more frequent surveys for some time," said Judi Lund Person of the National Hospice and Palliative Care Organization, which has 3,100 member hospices.
State surveys give "a chance to make sure providers and staff know what regulators are looking for," Person said. Currently, a hospice staff can turn over completely without a certification survey, she said.
The federal government, which contracts with states to do the hospice surveys, sets the priorities, said Bill Bell, who heads the Illinois Department of Public Health division responsible for the surveys. Hospital surveys and complaints have top priority in that system, Bell said. Even complaints from citizens about hospices go through the federal government, Bell said.
"If the federal government feels the complaint significant enough to investigate, they'll say, 'Go do this investigation,'" Bell said.
During a survey, a state can cite a hospice for problems with patient care. If problems are severe, a hospice can be eliminated from the Medicare program, but that is the only enforcement tool available to the federal government.
In contrast, the government can fine or deny Medicare payments to a nursing home with problems. The report recommends changes in the law to allow other enforcement tools for hospices. The report also recommends more frequent surveys.
The report was based on data from 2,537 active hospice providers in 2005.
"Hospice facilities should be surveyed timely so that problems can be detected and addressed," said Daniel Levinson, inspector general of the Health and Human Services Department, in a prepared statement.
The Centers for Medicare and Medicaid Services sets the frequency of hospice certification as part of its budget process. In fiscal year 2005, the centers required hospice certification surveys every six years, a standard in effect since 2000.
In 2006, the agency changed the frequency requirement to every eight years.
As of July 2005, according to the report, 14 percent of Medicare hospices were past due for certification, the report said. On average, they had not been surveyed for nine years, which was three years longer than the centers' standard at the time.
Study urges new system for elderly care
The aging baby boom generation is likely to increase the nation's disabled population, and a study says the United States needs a better system to provide care for them. More than 40 million Americans currently have some sort of disability, the Institute of Medicine reported Tuesday.
And a decline in physical activity and increase in obesity and diabetes in younger generations raises concerns that, as the nation ages, an increasing share of the population will experience disability, the Institute said.
"The number of Americans who have disabilities will grow significantly in the next 30 years as the baby boom generation enters late life," said Alan M. Jette, director of the Health and Disability Research Institute at the Boston University School of Public Health.
"If one considers people who now are disabled, those likely to develop a future disability and people who are or will be affected by the disabilities of family members or others close to them, it becomes clear that disability will eventually affect the lives of most Americans," said Jette, chairman of the committee that prepared the report.
He added: "The sobering reality, however, is that over the past two decades, far too little progress has been made in adopting major public policy and practice advances to reduce disability in America."
The Institute of Medicine is a branch of the National Academy of Sciences, which is an independent organization chartered by Congress to advise the government on scientific matters.
In a previous report in 1997, IOM said the federal research into disability was inadequate and called for more.
Nonetheless, the new report says, federal spending on this research remains "minuscule in relation to current and future needs."
The study concluded that action "taken sooner rather than later — is essential for the nation to avoid a future of harm and inequity and, instead, to improve the lives of people with disabilities."
Among the recommendations, the report called on the Congress and federal agencies to:
_Increase funding for research into clinical health services, social, behavioral and other disability problems.
_Strengthen provisions of the Americans with Disabilities Act to ensure that health care facilities are accessible to the disabled.
_Eliminate the two-year waiting period for Medicare eligibility for those who are receiving Social Security Disability Insurance.
_Modify the "in-home-use" requirement for Medicare coverage of durable medical equipment. That requirement now prevents payment for equipment that can be used both in and outside the home, the report said.
_Increase educational programs for health professionals caring for the disabled.
_Develop a system for monitoring the number and types of disabled people through the National Center for Health Statistics, Census Bureau and Bureau of Labor Statistics.
TV Food Ads Lead to Weight Gain in Kids
Television food ads prompted a 134 percent increase in the amount of food eaten by obese children, says a study by British researchers.
The study of 60 children, ages 9 to 11, also found that overweight children ate 101 percent more, and normal weight children ate 84 percent more, after they were shown a series of TV food and toy ads, followed by a cartoon.
A child's weight seemed to influence what they ate. The children in the study were provided with different kinds of foods, and the obese children consistently chose the highest fat item -- chocolate. Overweight children preferred jelly sweets, as well as chocolate.
"Our research confirms food TV advertising has a profound effect on all children's eating habits -- doubling their consumption rate. The study was also particularly interesting in suggesting a strong connection between weight and susceptibility to over-eating when exposed to food adverts on television," Dr. Jason Halford, director of the Kissileff Human Ingestive Behaviour Laboratory at the University of Liverpool, said in a prepared statement.
The study was presented this week at the European Congress on Obesity in Budapest.
The researchers plan further studies to investigate whether increased responsiveness to TV food ads or large amounts of TV viewing can predict childhood obesity.
Pneumococcal Strains Not Covered by Vaccine on the Rise
While the pneumococcal vaccine for children is highly effective, strains of the bacteria not covered by the vaccine are emerging as potential threats in certain populations.
A new U.S. government investigation has found that in Alaskan Native children who are already protected against seven strains of pneumococcal disease due to vaccination, the rate of serious infection by other strains is increasing by as much as 140 percent.
"The vaccine has been very effective and has done exactly what we hoped it would do. It's decreased the incidence of invasive pneumococcal disease (covered by the vaccine strains) by 95 percent in Alaskan Native children," said the study's lead author, Dr. Rosalyn Singelton, a visiting researcher for the U.S. Centers for Disease Control and Prevention in Anchorage, Alaska. "But, we've recently seen a significant increase in emerging non-vaccine serotypes."
The bacterium Streptococcus pneumoniae causes a variety of pneumococcal diseases, according to the CDC. Some are relatively mild, such as ear infections, while others are potentially life-threatening, such as pneumonia, meningitis and blood infections.
In 2000, the PCV7 pneumococcal conjugate vaccine first became available for infants and children. The vaccine includes the seven strains or serotypes of the bacteria that commonly cause pneumococcal disease in the United States.
Alaskan Natives have traditionally had higher rates of pneumococcal disease, according to the study. Before the introduction of the PCV7 vaccine, Alaskan Native children had three times the rate of invasive pneumococcal disease compared to the overall U.S. population. Possible reasons for this, according to Singleton, were overcrowding in small households, spending large amounts of time indoors and a lack of running water in many communities.
The new study, published in the April 25 issue of the Journal of the American Medical Association, included surveillance data from the beginning of 1995 through 2006.
The researchers found that within three years of the introduction of the vaccine, the overall rates of invasive pneumococcal disease in Alaskan Native children under age 2 was down by 67 percent.
However, when the researchers compared the two-year periods of 2001-2003 to 2004-2006, they saw an 82 percent increase in the rate of overall invasive pneumococcal disease in Alaskan Native children under 2. For strains not covered by the vaccine, the rate jumped by 140 percent compared to the pre-vaccine period.
One strain in particular, serotype 19A, was responsible for almost one-third of the non-vaccine covered disease, according to the study.
"This is a warning sign that this may occur in other populations," said Singleton, who pointed out that researchers have already been anticipating this shift and are working on second-generation pneumococcal vaccines.
Dr. Katherine Poehling, a pediatrician at Brenner Children's Hospital at Wake Forest University School of Medicine in Winston-Salem, N.C., said, "The serotype replacement is occurring to a greater extent in this (Alaskan Native) population, but it will happen in others."
Poehling, who wrote an accompanying editorial in the same issue of the journal, said, "This study is helping us to make sure that we maintain the magnificent gains we've seen over the last seven years."
Along with receiving the pneumococcal vaccine, Singleton said that other potential ways to reduce the incidence of disease are good hand-washing, breast-feeding your baby if you can, and delaying putting children into day care if possible.
Fear affects emergency care for child with asthma
Parents' psychological responses to asthma attacks are among the strongest motivators of seeking accident and emergency (A&E) services for their child, according to a study conducted in London.
In contrast, characteristics of the home environment, such as dampness, overcrowding, or living with a smoker, have little effect on use of emergency departments.
Children with asthma often use A&E services, Dr. Lindsay Forbes, from Springfield University Hospital, and associates note in their paper, published in the journal Thorax. To find out what triggers a visit to A&E, they studied children with asthma residing in south-east inner London, which has a high poverty rate.
The team identified 209 children ages 3 to 14 years old who were treated at an A&E for asthma over a 1-year period. Another 712 randomly chosen subjects who also had asthma but had not attended an A&E during the year prior to their enrollment. The data came from patients' records and questionnaires they were asked to completed.
The authors found that patients who had attended an outpatient clinic with a family doctor during the previous year were 13 times more likely to visit A&E.
Parents who reported feeling alone or experiencing panic or fear when their child's asthma got worse, or who believed they would get quicker service in an A&E, were 2- to 3-fold more likely to bring their child to the emergency department.
To reduce A&E use for asthma in children, Forbes and associates recommend that "health service planners should take a broader approach, considering what is the most appropriate setting for treating asthma attacks for children of different levels of attack severity, ensuring that services are accessible and address parents' concerns, and that the different parts of the health service communicate appropriate care pathways effectively and consistently to parents."
In wake of vaccine, new pneumonia strains emerge
While a new vaccine has all but eradicated common causes of pneumonia, meningitis and ear infections in children, new strains of bacteria not covered by the vaccine have emerged, U.S. researchers said on Tuesday.
Since the introduction of Wyeth's wildly successful vaccine Prevnar in 2000, doctors have been waiting and watching for the arrival of replacement bacteria that could undo its progress.
Now they may have found it.
Researchers from the U.S. Centers for Disease Control and Prevention have noted an increase in the rates of bacterial infections not covered by the current pneumococcal vaccine among native children in Alaska.
"People are on top of it. It is not unexpected, but it is important," Dr. Katherine Poehling of Brenner Children's Hospital at Wake Forest University in Winston-Salem, North Carolina, said in a telephone interview.
The vaccine, also called heptavalent pneumococcal conjugate vaccine or PCV7, is marketed as Prevnar in the United States and Canada and as Prevenar elsewhere in the world.
Given initially at 2, 4 and 6 months of age, it protects children from bacteria that often cause ear infections and drug-resistant pneumonia.
"Because of the surveillance, we are seeing it and we can act in a timely manner and maintain the benefits that we've seen," said Poehling, who wrote a commentary on the study, published in the
Journal of the American Medical Association.
The CDC's Dr. Rosalyn Singleton and colleagues studied pneumococcal infections such as pneumonia, meningitis or blood infections known as bacteremia that occurred from 1995 through 2006.
They found that in the three years after introduction of Prevnar, from 2001 through 2003, these diseases fell by 67 percent among native Alaskan children younger than age 2 and 61 percent in non-native children in the same age group.
Between 2001-2003 and 2004-2006, these infection rates remained stable in non-native Alaskan children younger than 2, but jumped 82 percent among Alaska Native children, who are more prone to the infections.
Since 2004, diseases caused by strains of bacteria not covered by the vaccine have risen by 140 percent compared with the pre-vaccine period.
During the same period, diseases caused by the vaccine-covered strains fell by 96 percent.
"The big news is the vaccine is highly successful. It has prevented a tremendous amount of disease, and it is still preventing a lot of disease in these children," Poehling said.
She said a new vaccine by Wyeth is in late-stage clinical trials that could help protect against these new strains.
The current vaccine, one of Wyeth's biggest-selling products with annual sales of more than $2 billion, targets seven strains of pneumococcal bacterial.
The new vaccine would target 13 strains of the bacterial. Wyeth has said it plans to seek regulatory approvals for the new vaccine in early 2009. GlaxoSmithKline is working on a rival to Prevnar.
Breast-feeding won't deter obesity
While breast-feeding has many benefits, it won't prevent a child from becoming fat as an adult, says a new study that challenges dogma from U.S. health officials.
The research is the largest study to date on breast-feeding and its effect on adult obesity.
"I'm the first to say breast-feeding is good. But I don't think it's the solution to reducing childhood or adult obesity," said the study's lead author, Karin Michels of Harvard Medical School.
The U.S. Centers for Disease Control and Prevention promotes breast-feeding as a way to reduce children's excess weight, and the guidelines for federal chronic disease prevention grants to states call for breast-feeding promotion. Some health officials say 15 to 20 percent of obesity could be prevented through breast-feeding.
A
CDC official said he couldn't comment on the new research because he hadn't fully reviewed it. But many previous studies have linked breast-feeding and lower rates of childhood obesity, he noted.
Perhaps the obesity-preventing benefits of breast-feeding are strong for children but wane by adulthood, said the official, Larry Grummer-Strawn.
"It would be remarkable to find a behavior that you engage in for one year of life and see detectable effects from it 40 years later," said Grummer-Strawn, chief of the CDC's maternal and child nutrition branch.
Good or bad eating and exercise habits, developed later in life, may sustain or erase initial weight-related benefits from breast-feeding, he and other experts said. Of course, that doesn't take away the other benefits of breast-feeding, such as building a child's immunity to disease.
The Harvard study, published online this week in the International Journal of Obesity, involved nearly 14,500 women who were breast-fed as infants and more than 21,000 who were not.
In 1989, the women were asked their height and weight and what those measurements were when they were children and at age 18. Then every two years, through 2001, they were asked to update their weight information. The surveyed women were all between 25 and 42 at the time of the 1989 questionnaires, Michels said.
In 2001, the mothers of these women were sent a questionnaire asking if their daughters had been breast-fed and for how long.
When possible, researchers checked medical records to confirm what the mothers and daughters recalled, but breast-feeding is not routinely documented. Still, the researchers believe the women's recollections of breast-feeding are reliable.
"A mother knows whether she breast-fed her child," said Michels, an associate professor of epidemiology.
Women who were breast-fed for at least a week had a risk of being overweight or obese that was nearly identical to that of women who were bottle-fed, the study found. And duration of breast-feeding didn't seem to make a difference. The women who had been breast-fed for more than nine months had a risk of becoming overweight or obese similar to that of women breast-fed less than one week.
The study involved only women, but the researchers believe the results are equally true for men, Michels said.
Michels believes that one reason previous studies might have been misleading about breast-feeding's effects on weight gain is that many of those studies failed to properly account for socioeconomic factors that also may have had an influence.
An Emory University pediatrics expert said he is not surprised by the study's findings about adults. But he said breast-feeding is beneficial for children, and the government's health message should not change.
"The first step is preventing childhood obesity. We know obese children have to work harder to not become obese adults," said Dr. Robert Geller, an associate professor who also is chief of pediatrics for Atlanta's Grady Health System.
Fat workers cost employers more
Overweight workers cost their bosses more in injury claims than their lean colleagues, suggests a study that found the heaviest employees had twice the rate of workers' compensation claims as their fit co-workers.
Obesity experts said they hope the study will convince employers to invest in programs to help fight obesity. One employment attorney warned companies that treating fat workers differently could lead to discrimination complaints.
Duke University researchers also found that the fattest workers had 13 times more lost workdays due to work-related injuries, and their medical claims for those injuries were seven times higher than their fit co-workers.
Overweight workers were more likely to have claims involving injuries to the back, wrist, arm, neck, shoulder, hip, knee and foot than other employees.
The findings were based on eight years of data from 11,728 people employed by Duke and its health system. Researchers found that workers with higher body mass indexes, or BMIs, had higher rates of workers' compensation claims.
The most obese workers — those with BMIs of 40 or higher — had the highest rates of claims and lost workdays. BMI is a measure of height and weight. A 6-foot, 300-pound person, for example, has a BMI of just over 40.
Study co-author Dr. Truls Ostbye said the findings should encourage employers to sponsor fitness programs.
"There are many promising programs," Ostbye said. "We'd like to see more research about what is truly effective."
James Hill, who heads the Center for Human Nutrition at the University of Colorado, said managers will pay attention to the findings because injuries mean more immediate financial losses than the future health-care costs of diabetes and heart disease.
"When you see that claims rates double, I think that's going to get people's attention," Hill said.
But there isn't enough good information about employer-sponsored programs that work, said John Cawley, an expert in the economics of obesity at Cornell University. Employers don't know whether paying for nutrition counseling, obesity surgery or anti-obesity drugs through health insurance makes economic sense, he said.
"It's now apparent to everybody that obesity is a big problem," Cawley said. "But the research isn't there to know where to get biggest bang for the buck."
Cawley noted that BMI does not distinguish muscle from fat and can equate a buff body builder to a couch potato. Although BMI, a measure of height and weight, is used in most obesity research, Cawley's research has found that blacks are particularly likely to be misclassified as obese by BMI.
New York employment attorney Richard Corenthal cautioned employers not to overreact with discriminatory policies.
"Employers need to be careful not to view this study as a green light to treat obese or overweight workers differently," Corenthal said.
The study, appearing in Monday's Archives of Internal Medicine, got funding from the National Institute for Occupational Safety and Health.
Breast-feeding no help in preventing adult obesity
Being breast-fed as a baby provides no protection against adult obesity, according to a U.S. study published on Tuesday.
Health agencies including the U.S. Centers for Disease Control and Prevention and the American Academy of Pediatrics encourage women to breast-feed their babies for at least six months, mostly because many studies show it leads to healthier babies.
It also reduces the risk of childhood obesity.
But the effects do not appear to extend into adulthood, according to a study in the International Journal of Obesity.
Karin Michels and colleagues at Harvard's Brigham and Women's Hospital studied 35,000 nurses working in the United States over a 12-year period.
Their mothers were asked to report on their breast-feeding habits.
When adjusted for socioeconomic factors, the researchers found breast-feeding had no significant effect on the body mass index or BMI of the nurses in adulthood. BMI is calculated as weight in kilograms divided by height in meters squared.
Breast-feeding for more than 6 months does appear to have a benefit in children. The study found these kids a had a leaner body shape at age 5, but this benefit did not extend into adolescence or adulthood.
The authors said that while breast-feeding promotes the health of mother and child, it is not likely to play an important role in controlling the obesity epidemic.
Tuesday, April 24, 2007
Health Tip: When Your Child Outgrows a Car Seat
If your child has already moved from a car seat to a booster seat and is outgrowing that as well, it's time to make sure she can safely ride in a car strapped in with a safety belt.
For the child to be safely restrained, it's important that the seat belt fits properly and can protect her in the event of an accident.
Here are some guidelines for the proper fitting of a child's safety belt from the American Academy of Pediatrics:
Melanoma in kids differs from the adult cancer
The demographics, site of appearance, and outcome of children and teenagers with melanoma differ from the features seen in young adults, according to study findings published in the Journal of Clinical Oncology.
The results suggest melanoma may be biologically different in children and adolescents.
"Melanoma is uncommon in teenagers and rare in younger children," Dr. Julie R. Lange, of Johns Hopkins Medicine, Baltimore, Maryland, and colleagues write. However, differences in this cancer between children and adults are not well understood.
Using the National Cancer Data Base, the researchers compared melanoma cases of children and teenagers who were between 1 and 19 years old with those for patients between 20 and 24 years.
Among the 3,158 children and teenagers, 96.3 percent had melanoma of the skin, the most common site; 3.0 percent had melanoma of the eye; and 0.7 percent had an unknown primary site. Skin melanoma was more common in girls (55 percent) than in boys, and in subjects older than 10 years (90.5 percent).
The authors detected a relationship between the demographics, the site of skin melanomas and age. Younger patients were significantly more likely to be male and nonwhite, to have primary tumors of the head and neck, and to have regional or distant cancer spread.
The patients were followed-up for an average of 59 months. An association was observed between poorer survival and more extensive disease progression and younger age. "Females had significantly better overall survival than males, except in patients aged 1 to 9 years," the investigators found.
Patients between 20 and 24 years with thinner melanomas had significantly better survival rates (96.8 percent) than patients with thicker tumors (82.4 percent)," Lange's team reports. However, within the younger group, survival rates were not significantly different between the thinner and thicker tumors.
The lack of prognostic value of tumor thickness in the young group suggests biologic differences, even more than does the demographic differences compared to the older patients, Dr. Lange and colleagues point out. "More research in the molecular genetics of pediatric melanoma is needed," they conclude.
SOURCE: Journal of Clinical Oncology, April 2007.
Potential rabies treatment fails two children
An experimental rabies treatment that saved the life of a teenager in 2004 has failed to help two other children infected with the deadly virus, U.S. experts said on Friday.
A 10-year-old Indiana girl and an 11-year-old boy in California both died despite getting the treatment that involves putting patients into a drug-induced coma and giving them antiviral drugs.
This means it is critical for parents and doctors to recognize quickly if a child may have been exposed to rabies and get treatment as quickly as possible, the team at the U.S. Centers for Disease Control and Prevention said.
Quick vaccination after exposure -- usually via a bite or some other contact with the saliva of an infected animal -- can save lives. But if a person begins showing symptoms, which are vague enough to be confusing, it is usually too late.
Rabies kills 55,000 people a year globally and affected 24 people in the United States in the years 2000 to 2006.
In 2004 a 15-year-old Wisconsin girl was successfully treated for rabies infection a month after she was bitten by a bat. It took doctors six days to figure out why she was ill but they quickly used drugs to put her into a coma, used a ventilator to keep her breathing and gave her the antiviral drug ribavirin.
She survived -- the first time anyone with documented rabies illness has lived without a rabies vaccination.
But the so-called Wisconsin protocol failed on the two U.S. children who became ill in September and November of last year, the CDC team said.
"To consider use of the Wisconsin rabies treatment protocol, the disease must be diagnosed as early in the course as possible, which requires enhanced clinical awareness of the disease among health-care providers," the CDC said in its report.
The 10-year-old Indiana girl's symptoms started with pain in her arm. It was days before her mother remembered that the girl had reported having been bitten by a bat that flew into her window the previous June.
The child died after 26 days in the hospital.
In the second fatal case, the 11-year-old boy had apparently been bitten by a rabid dog in the Philippines, perhaps two years before.
"Typical rabies incubation periods vary from 1 to 3 months after exposure," the CDC said. But longer time lags have been documented.
Obesity rising in Europe, especially in children
The number of overweight people in Europe is rising and there is an especially worrying trend of increasing childhood obesity and in the number of people who are grossly obese, according to recent studies.
Europe is facing major health and social burdens and the rise in obesity is reaching "epidemic" proportions, the 15th European Congress on Obesity in Budapest was told on Sunday.
Estimates show there are around 1.1 billion overweight people in the world, of whom 312 million are obese, and that in Europe 10-20 percent of men are obese and almost half the population is overweight.
Some 30 percent of children in Britain are obese or overweight, and percentages are rising in southern Europe, while in new
European Union states in eastern Europe, rates of obesity are surging at a time when health spending is being curtailed.
"More than 80 percent of children who are already obese will stay obese as adults," said Martin Fried of Prague's Charles University, who authored a major study on the effect of surgery on obese patients.
Fried estimates that there are around 11 million Europeans who are grossly obese, with a body mass index of 40 or more.
Body mass index (BMI) is a measure of body fat based on height and weight in which normal weight is in a BMI range of 18.5-24.9.
Obese people are far more likely to suffer early deaths, have health problems like type-2 diabetes, and have a lower quality of life, as well as being unable to participate in work, Fried told journalists on the sidelines of the conference.
Fried said surgery was increasingly a workable solution for obese adults and that far from competing for health resources, it was better than for example continuing to treat type-2 diabetes with drugs, as surgery offered a once-and-for-all solution for 80 percent of cases after six months to a year.
In Britain, which has one of the highest levels of childhood obesity in Europe, a study showed that community-based programs had a major impact on overweight and obese children.
Results of a 9-week trial program conducted by University College London (UCL) and Great Ormond Street Hospital for Children involving 107 families showed significant improvements in BMI, waistlines, lifestyle and self-esteem.
These results were sustained over 12 months, the study said.
"Obesity costs the nation 7 billion pounds a year. This popular community-based program has the potential to underpin effective national strategies for obesity treatment and preservation," said Professor Alan Lucas of UCL's child health department.
Childhood obesity: Breast is not necessarily best
Long-term research into obesity suggests that being breastfed as a child does not help prevent obesity later in life, a finding that contradicts guidelines in the United States and elsewhere.
Investigators in the United States looked at the health of 35,000 nurses working in the US between 1989 and 2001.
They asked the nurses' mothers to report on their breastfeeding habits when their child was a newborn, while the nurses themselves were asked to report their height, their current weight and their weight at 18.
The nurses were also asked to recall their body shape at ages five and 10 using a nine-level figure drawing.
Duration of breastfeeding did not affect the body mass index (BMI) -- a key indicator of fat -- in adulthood, according to their paper, which appears in the International Journal of Obesity.
Women who had been breastfed for more than nine months had a risk of becoming overweight or obese that was similar to that of women who had been breastfed for less than a week or exclusively bottle-fed.
"Breastfeeding, as good as it is, is not a solution to the obesity epidemic," Karin Michels, associate professor at Harvard Medical School and lead author of the study, told AFP.
"It's important to realize that there are much more important causes and reasons for the obesity epidemic."
The researchers found that women who had been breastfed for several months were indeed slightly slimmer in early childhood compared with those who had been bottle-fed.
But this difference is of "borderline statistical significance," according to Michels.
The mooted reason: breast-fed infants start off skinnier, but this is probably due to the natural limitations of available food in their first year of life -- and the difference does not extend to later years.
Breastfeeding does provide plenty of other benefits to mother and child, Michels pointed out.
Its vital nutrients help the child to build up its immune system and, as has been recently discovered, lessens a mother's risk for diabetes and heart disease, Michels said.
The paper contradicts the recommendations of the US Centers for Disease Control (
CDC) and the European Union's Childhood Obesity Programme, which promote breastfeeding as a method for controlling childhood obesity, with the eventual aim of curbing adolescent and adult obesity.
In another study released on Tuesday, the British journal Archives of Disease in Childhood concluded that primary schoolchildren should not be routinely screened for obesity and weight problems if there are no means to treat them.
The British government has introduced population weight monitoring in primary schools.
But the authors, led by Marie Westwood of the University of York, northern England, found no evidence to say the screening strategy worked and suggested it may even be potentially harmful if counselling and other help were not available.
Obesity is gaining pandemic proportions in many developed countries but also in emerging economies. Experts point the finger at sedentary lifestyle, persistent snacking and food that is rich in calories. Genetic factors, too, may be significant.
Monday, April 23, 2007
Elderly Need to Watch Vitamin D Levels
A lack of vitamin D may encourage disability in older adults, a new study finds.
Vitamin D, which can be obtained from food and is produced naturally by the body through exposure to the sun, plays an important role in bone health and muscle function and may help protect against diabetes, cancer, colds and tuberculosis.
About 25 percent of people over age 60 have low levels of vitamin D, say researchers reporting in the April issue of the Journal of Gerontology: Medical Sciences.
Older adults are prone to low vitamin D levels, because they tend to get less exposure to sunlight, and their skin is less efficient in producing vitamin D from sun exposure, said the study's lead author, Denise Houston, an instructor in internal medicine-gerontology at Wake Forest University School of Medicine. Older adults also may not get enough vitamin D from dietary sources such as fortified milk, juice and cereals.
She and her colleagues analyzed data from a study of 976 Italians age 65 and older and found that those with low levels of vitamin D scored five percent to 10 percent lower in tests of physical performance and grip strength.
While the researchers didn't look at whether low vitamin D levels actually cause poor physical performance, they said the findings suggest the need for additional research in this area.
Current recommendations say that people ages 50 to 69 should get 400 international units (IUs) of vitamin D per day, and people over age 70 should get 600 IUs per day. However, many experts believe that may not be enough.
"Higher amounts of vitamin D may be needed for the preservation of muscle strength and physical function as well as other conditions such as cancer prevention. The current recommendations are based primarily on vitamin D's effects on bone health," Houston said.
Study sees major depression connection to diabetes
Elderly people who are depressed are more likely to become diabetic than those who are not, according to a study that suggests depression may play a role in causing the most common form of diabetes.
Writing on Monday in the Archives of Internal Medicine, the researchers said people with a high number of symptoms of depression were about 60 percent more likely to develop type 2 diabetes, formerly called adult-onset diabetes, than people not considered depressed.
Unlike some other studies examining a link between depression and diabetes, this one looked at the effects not only of single bouts of depression but also of chronic depression and depression that worsened over time. It found an increased risk for diabetes in each of those scenarios.
Researchers tracked 4,681 men and women in North Carolina, California, Maryland and Pennsylvania ages 65 and older, with an average age of 73, who did not have diabetes when the study began in 1989.
For 10 years, they were screened annually for 10 symptoms of depression, including those related to mood, irritability, calorie intake, concentration and sleep.
"People who report higher depressive symptoms may not take as good a care of themselves as they should," lead researcher Mercedes Carnethon of the Northwestern University's Feinberg School of Medicine said in an interview.
"For example, they may be less physically active, and thus more likely to gain weight, which is the primary risk factor for diabetes," Carnethon said.
But the study statistically accounted for known lifestyle risk factors for diabetes like being overweight and sedentary, and still found that depression increased the risk of diabetes.
Carnethon said the findings suggest depression may play a role in causing diabetes. While the study did not explore possible biological mechanisms, Carnethon said a high level of the stress hormone cortisol in depressed people may be the reason.
Diabetes is marked by high levels of blood glucose resulting from defects in the production or action of insulin, which allows glucose to enter the body's cells for use as fuel. High cortisol levels, the researchers said, may cut insulin sensitivity and raise fat deposits around the waist.
"Diabetes not only causes heart disease, but is strongly related to strokes, blindness, kidney failure, amputations. Diabetes is a very serious condition that's highly prevalent in older adults," Carnethon said.
Diabetes is a growing worldwide problem, closely tied to obesity. Type 2 diabetes accounts for about 95 percent of all cases.
The findings point to the importance of doctors screening older adults for depression and, if it's present, for diabetes risk, Carnethon said.
Medicare fund exhausted in 2019
The U.S. Medicare Hospital Insurance trust fund will exhaust its assets in 2019 instead of the 2018 date forecast last year due to bigger payroll tax collections, a report from the fund's trustees said on Monday.
The Social Security trust fund also extended its exhaustion date by a year to 2041. Despite the slight improvement reported by the trustees, the Bush administration said the two popular programs for the elderly needed urgent reform.
"Without change, rising costs will drive government spending to unprecedented levels, consume nearly all projected federal revenues and threaten America's future prosperity," Treasury Secretary Henry Paulson said in a statement.
The Medicare report raised a "funding warning" that is meant to trigger congressional debate over trimming costs of the health care program, which faces huge strains from rapidly rising costs and the aging baby boom generation.
Also, the trustees projected Social Security outlays to outstrip tax income in 2017, the same date as forecast last year.
President George W. Bush said the new Medicare prescription drug program, which relies mostly on private insurers to deliver the benefits to seniors, should serve as an example during the Medicare reform debate, adding, "competition works, competition can lower price, and improve the quality" for beneficiaries.
Bush said the cost of delivering the Medicare Part D drug benefit turned out to be substantially less than originally estimated, but the report warned that financing for the drug program and other parts of Medicare will have to increase rapidly to match expected cost increases.
Paulson said time was of the essence for lawmakers to address the projected funding shortfall for the two programs. "The longer we delay, the larger the required adjustments will be -- and the burden of making those adjustments will fall more heavily on future generations," he said.
