Mercury from vaccines disappears quickly
Thu, 31 Jan 2008 02:31:22 GMTBy CARLA K. JOHNSON, Associated Press Writer
CHICAGO - Mercury from vaccines seems to disappear rapidly from the blood, returning to pre-vaccination levels in one month, according to a small study of children in Argentina.
The findings bolster the argument that a mercury-based vaccine preservative doesn't cause autism in children, although it's unclear from the study whether some mercury may linger elsewhere in the body.
The research addresses an unanswered question about the safety of thimerosal, a preservative that has been eliminated from routine U.S. vaccines, and breaks down as ethyl mercury in the body. It is still used in other countries, including Argentina.
Scientists assumed the health risks from ethyl mercury were similar to methyl mercury from eating fish. And in 1999, the federal government and vaccine manufacturers agreed that thimerosal should be reduced or eliminated in vaccines to lower exposure to mercury from all sources. The decision was based on what was known about methyl mercury exposure.
The new findings suggest that methyl mercury and ethyl mercury are very different and that the removal of thimerosal from vaccines may have been over-cautious.
"The study supports the decision by the World Health Organization to continue to permit thimerosal to remain in vaccines for the world's children," said study co-author Dr. Michael Pichichero of the University of Rochester in Rochester, N.Y. He said thimerosal vaccines are cheaper to produce and therefore more accessible to much of the world.
In the U.S.-funded study, blood samples were taken from 216 healthy babies before and after they got vaccines containing the preservative thimerosal. Blood levels of mercury were highest shortly after the babies were vaccinated and fell to pre-vaccination levels within a few weeks.
"The amount found in the blood was about one-tenth of that predicted in that the late 1990s and the length of time it stays in the blood is one-tenth of that predicted," Pichichero said.
Mercury levels also were measured in the babies' stools and urine. In the stool samples, the levels were highest after vaccination and also fell, but more slowly than blood levels. There was no significant amount of mercury in the urine.
The authors could not determine what happened to all the mercury after it left the blood. All the infants gave samples twice: before vaccination and at one other time, ranging from 12 hours later to 30 days.
The study will be published in the February issue of the journal Pediatrics. The medical journal released the findings early because of a controversy surrounding a new TV series premiering Thursday, which features a lawyer who argues in court that a flu vaccine made a child autistic.
The journal is published by the American Academy of Pediatrics, which on Monday called on ABC to cancel the first episode of the series, "Eli Stone," saying that it perpetuates the myth that vaccines can cause autism.
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 thimerosal is to blame has been repeatedly discounted in scientific studies.
Pichichero said he has received research grants and served as a consultant to several vaccine makers, but said there was no industry involvement in the new study. He is an unpaid consultant to the WHO on vaccines.
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On the Net:
Pediatrics: http://www.aap.org
Study links stress to soldiers maladies
Wed, 30 Jan 2008 22:10:55 GMTBy MARILYNN MARCHIONE, AP Medical Writer
The role of traumatic brain injury — blamed for symptoms plaguing thousands of soldiers returning from Iraq — might be overstated, contends a provocative military study that offers hope for successful treatment.
In many cases, post-traumatic stress and depression may be driving the symptoms, doctors reported Wednesday. And that's good news because those are treatable.
The study by U.S. military doctors was praised by outside experts who found the conclusions convincing.
Returning soldiers have struggled with memory loss, irritability, trouble sleeping and other problems. Many have suffered mild blast-related concussions, but there is no easy way to separate which symptoms are due to physical damage and which are from mental problems caused by the traumatic stress of war. Imaging of the brain is being tested, but hasn't yet proven to be helpful.
The new study, based on a survey of 2,525 soldiers, found that brain injury made traumatic stress more likely. The study tied only one symptom — headaches — specifically to brain injury.
"We found that the symptoms and health concerns that we expected to be due to the concussion actually proved to be more strongly related to PTSD," or post-traumatic stress disorder, and depression, said Dr. Charles Hoge, a colonel and psychiatry chief at Walter Reed Army Institute of Research who led the study. "There isn't a clear delineation between a psychological and a physical problem."
Other doctors were optimistic about treatment efforts.
"It gives us hope, because we've got good treatments for PTSD," said Barbara Rothbaum, a psychologist who heads a trauma recovery program at Emory University in Atlanta. "If we can relieve the PTSD and depression, I'm hoping we'll see alleviation of a lot of these physical symptoms."
Hoge reported on the survey Wednesday at a military health conference in Washington. Results also were published in Thursday's New England Journal of Medicine.
The journal's editor-in-chief, Dr. Jeffrey Drazen, said editors initially were skeptical of the findings, which depart from the gloom-and-doom picture some have painted for soldiers with brain injuries.
However, the solid research methods and the "strong and robust" data linking stress and concussion symptoms persuaded them, said Drazen, who is a scientific adviser to the Veterans Administration.
The case of Eric O'Brien, a 33-year-old Army staff sergeant from Iowa's Quad Cities, suggests the researchers may be right.
After an explosion in Baghdad in 2006, O'Brien was treated at Vanderbilt University's brain injury rehabilitation program and at Fort Campbell, Ky., for post-traumatic stress. Now he is preparing to redeploy, this time to Afghanistan.
"I retested on a lot of the tests and they showed a pretty decent increase," he said of his mental function tests. As for stress, "I don't know if it's something you just learn to deal with or if it just gets a little bit better over time," he said. "It's not as bad as it was."
The vast majority of brain injuries, or concussions, are mild, but the military previously estimated that one-fifth cause symptoms lasting a year or more.
The new study tried to pin down the potential long-term effects of mild brain injury, through an anonymous survey of two Army combat brigades — one active and one Reserve — in 2006, several months after they returned home from Iraq.
Fifteen percent of soldiers reported a mild brain injury — having been knocked unconscious or left confused or "seeing stars" after a blast. They were more likely than other soldiers to report health problems, missing work, and symptoms such as trouble concentrating.
The worst symptoms were in soldiers who lost consciousness. About 44 percent of them met the criteria for post-traumatic stress, compared with 16 percent of soldiers with non-head injuries, and only 9 percent of those with no injuries.
"The same incident might have triggered both processes," Rothbaum said, noting that after World War I, "they thought that shell shock was a neurological disorder and it turned out to have a lot of overlap with the psychological disorder."
However, Dr. Greg O'Shanick, a psychiatrist and medical director for the advocacy group Brain Injury Association of America, said it would be over-simplifying to think that treating PTSD alone would be enough.
"It's like having fleas and ticks," he said. Getting rid of one may not make you stop itching, "and if you've got one, it makes it harder to handle the other."
Concussions may compound stress by damaging brain areas that tamp down responses to fear, Richard Bryant, a psychologist at the University of New South Wales in Sydney, Australia, writes in an editorial in the journal.
"PTSD and depression may be the primary problem," he writes. "Soldiers should not be led to believe that they have a brain injury that will result in permanent change."
The military recently started screening all returning troops for concussions. Any soldiers who saw intense combat should be similarly checked for stress disorder, said Anthony Stringer, director of Emory University's neuropsychology rehabilitation program.
The new study can be viewed as positive "if the results are used to make sure that soldiers have the care they need when they return," he said.
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On the Net:
New England Journal: http://www.nejm.org
Army Medicine: http://www.armymedicine.army.mil
Defense and Brain Injury Center: http://www.dvbic.org/
Centers for Disease Control:
http://www.cdc.gov/ncipc/factsheets/tbi.htm
National Institutes of Health:
http://www.ninds.nih.gov/disorders/tbi/detail_tbi.htm
Gentler fix for artery bulge proves best
Wed, 30 Jan 2008 22:33:46 GMTBy MARILYNN MARCHIONE, AP Medical Writer
A new study may help older people and their doctors decide how to treat a very common and dangerous problem — a bulging abdominal artery threatening to burst.
Fixing these weak spots by inserting a fabric sleeve into the artery, like a new tube in a bicycle tire, led to fewer deaths and complications than traditional surgery to implant this patch, the study found.
The study involved more than 45,000 Medicare patients, average age 76, with "AAAs," or abdominal aortic aneurysms. More than 200,000 of these are diagnosed in the United States each year. The number is growing since the government recently recommended screening male smokers over 55 for the problem, which is often fatal if the vessel bursts.
In the study, nearly 5 percent of patients died after surgery, versus about 1 percent of those treated the less invasive way. After four years, the non-surgery group was three times more likely to suffer a rupture, but this risk was small and offset by other complications in the surgery group.
The study was led by doctors at Harvard University and Beth Israel Deaconess Medical Center in Boston, with Medicare researchers. Results were published in Thursday's New England Journal of Medicine.
"This represents a real-world look" at results in ordinary hospitals, not just in big research centers, said Dr. Barry Katzen, medical director of Baptist Cardiac and Vascular Institute in Miami. He has been involved in key studies on the less invasive procedure and has consulted for at least one device maker.
Four brands of these artery patches are sold in the United States and cost $10,000 to $15,000. Including this expense, surgery costs $35,000 to $40,000 — about $5,000 more than the less invasive approach, Katzen said.
"Aneurysms do run in families," so anyone with that history should be checked, which is done with a painless ultrasound exam or CT scan, he said.
Researcher admits leaking diabetes study
Wed, 30 Jan 2008 22:10:14 GMTBy MARILYNN MARCHIONE, AP Medical Writer
A Texas doctor leaked confidential research to the makers of the popular diabetes drug Avandia weeks before a study was published tying the drug to higher heart risks, the scientific journal Nature reported Wednesday.
Dr. Steven Haffner, of the University of Texas Health Science Center at San Antonio, broke confidentiality rules for medical journal peer reviewers when he gave the Avandia study to GlaxoSmithKline PLC 17 days before it was published last May in the New England Journal of Medicine, the Nature report says.
The study, linking Avandia to a 43 percent greater risk of heart attacks, got widespread attention, led the federal Food and Drug Administration to issue a safety alert, and caused the company's stock to drop. The study was led by Cleveland Clinic cardiology chief Dr. Steven Nissen.
Haffner admitted faxing the study to a Glaxo employee he worked with on an earlier Avandia study, says the report published online Wednesday in the news section of Nature.
"Why I sent it is a mystery. I don't really understand it. I wasn't feeling well. It was bad judgment," Nature quotes Haffner as saying.
Haffner referred requests for comment Wednesday to the university. Dr. William Henrich, dean of the school of medicine, released this statement: "This issue has just come to light on our campus. We are embarking on a complete investigation of the facts. Once the facts are understood, we will take swift and appropriate action. The University of Texas Health Science Center at San Antonio adheres to strict ethical standards."
It's not clear that Glaxo took any action after getting the confidential information. Most scientific journals have outside scientists, "peer reviewers," who study research to be sure it is solid before it is published.
The leak came to light last summer, when Glaxo officials informed the Senate Finance Committee that Haffner had sent them the study, according to a letter released Wednesday by Sen. Charles Grassley, R-Iowa, the panel's ranking member. Grassley wants Glaxo to explain what it did after learning that the negative study was imminent.
Glaxo spokeswoman Nancy Pekarek told Nature that the company did not offer any input to Haffner on the study and, to her knowledge, did not inform the New England Journal of the breach, the Nature article says.
Spokesmen for the New England Journal would not say what if any actions had been taken against Haffner.
"We consider the peer-review process to be confidential. Any breach of ethics by a reviewer would be taken very seriously by the editors, but would be handled as a private matter," says a statement from the journal.
Last year, the journal restricted future publishing rights of another peer reviewer, Columbia University's Dr. Martin Leon. He had discussed confidential results of another controversial study, involving angioplasty and heart stents, before its scheduled publication.
