Toxins

AUTISM: Bad air, genetics add up to higher risk

Posted on Dec 7, 2013

AUTISM: Bad air, genetics add up to higher risk

Air pollution and a common genetic makeup may interact to significantly increase a baby’s risk for autism, USC scientists found. The researchers at USC’s Keck School of Medicine cautioned in an interview that they need to do more studies to replicate their findings. The study, to be published in the January 2014 edition of the journal Epidemiology, found that children with the specific gene who spent their in-utero months and their first year after birth in polluted areas of California had three-fold higher risks for autism disorders. “We need to do more studies, but the genetic disposition and air pollution appear to work together to increase the risk of autism more than the risk of each one alone,” said the study’s lead author, Heather E. Volk, an assistant professor of research in preventive medicine at the medical school. Volk’s earlier work found that children had twice the risk of developing autism if their mothers lived within 1,000 feet of a busy freeway during pregnancy. For this research, Volk collaborated with genetics expert Daniel B. Campbell, an assistant professor in psychiatry and behavioral science at the USC medical school. Campbell explained by telephone that roughly half the population has what geneticists call the “MET receptor tyrosine kinase gene.” The gene is found in about 60 percent of people who have autism, indicating that those with the gene have a higher risk, he said. THE CHILDREN To probe the potential interplay between the gene and air quality, Volk, Campbell and their colleagues analyzed the genetics and air pollution exposures of 408 children in the Sacramento, San Francisco and Los Angeles areas; the children’s cases already were being tracked for research purposes. Of those children, 252 met the diagnostic criteria for the spectrum of autism disorders. Using regional air quality readings and traffic proximity data, the research team determined each child’s air pollution exposure while they were fetuses and in their first year after birth — a critical period in the development of the brain and other organs. The scientists used a blood test to determine each child’s genetics. The team found no increase in the autism risk among the children who had the gene but breathed relatively clean air. But those who had the gene and were exposed to air pollution were three times more likely to have the disease, Volk said. Beth Burt, president of the Autism Society Inland Empire, said she appreciates the research. “It is fascinating and important work,” said Burt, a Corona resident who has an autistic son who is 20. “It is not an either/or situation — genetics or the environment,” she said. “But it may be the combination of a genetic predisposition with an environmental trigger.” Lillian Vasquez, who also has a 20-year-old son with autism, said she was not surprised by USC’s findings. She said she has always thought autism was the result of genetics and some sort of trigger, such as a vaccination or an artificial sweetener. “Air pollution as a trigger seems quite plausible,” she said. Vasquez, vice president of the Inland autism society, has lived in Colton since before her pregnancy. Colton, like most of the Inland area, has long had unhealthful levels of air pollution. OTHER RESEARCH Autism disorders are incurable, lifelong brain disabilities characterized by problems with social interaction, communication and repetitive behaviors. The Centers for Disease Control and Prevention estimates that one in 88 children in the United States has an autism disorder. Thousands of studies have linked air pollution to lung, heart and circulatory disorders. The work by Volk and her colleagues, however, is part of a...

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Toxin-Emitting Bacteria May Be Environmental Trigger for MS

Posted on Nov 15, 2013

Toxin-Emitting Bacteria May Be Environmental Trigger for MS

Could eating meat from animals infected with one type of Clostridia bacteria be the MS ‘smoking gun?’ Researchers may have unearthed a trigger for multiple sclerosis (MS) that’s been hiding in plain sight. Scientists from Weill Cornell Medical College and Rockefeller University have identified a bacterium they believe can trigger MS—and it’s found just about everywhere, including dirt. Their study, published in PLOS ONE, is the first to identify the bacterium, Clostridium (C.) perfringens type B, in humans. They first identified it in the blood of a 21-year-old woman with MS who was having a relapse. She was part of the Harboring the Initial Trigger for MS (HITMS) observational study launched by Timothy Vartanian, a professor of neurology and neuroscience at Weill Cornell Medical College and director of the Judith Jaffe Multiple Sclerosis Center at New York-Presbyterian Hospital and Weill Cornell, and Kareem Rashid Rumah, an MD/PhD student at Weill Cornell and lead investigator. See 13 Early Signs of MS » Getting the Dirt on C. perfringens C. perfringens, found in soil, is one of the most common types of bacteria in the world. It has five subsets, A through D. Type A commonly occurs in the human gastrointestinal tract and is thought to be harmless. Types B and D, however, can emit a harmful substance called epsilon toxin when eaten by grazing livestock. The substance travels through the bloodstream, crossing the blood-brain barrier and destroying myelin, causing MS-like symptoms in the animals. Vartanian, Rashid, and their team wondered if C. perfringens types B or D could be identified in humans. They tested the blood of both MS patients and healthy control subjects. In samples from MS patients, the levels of antibodies to the toxins were 10 times higher than in the healthy controls. They also noted that only one sample in 100 from the healthy controls showed any sign of exposure to the bacteria. Researchers hypothesize that eating grazing animals who are infected with the bacteria could be the way C. perfringens Type B is introduced into the human digestive system. The human gut plays host to many types of bacteria, not all of them bad. Some are actually necessary for maintaining good health. Researchers suppose that the reason one person reacts to the toxin emitted by the bacteria while another does not may depend on the natural balance of bacteria in a person’s gut. Learn 6 Surprising Facts About the Microbes Living in Your Gut » “We believe the toxin enters the blood from the gut,” said Vartanian in an interview with Healthline. “Once in the blood, the toxin binds to a specific receptor present on the [lining of] the brain blood vessels, resulting in injury to the blood brain barrier (BBB). The toxin in the blood can then enter the brain at focal sites of BBB injury and bind to the same receptor on oligodendrocytes, the myelin forming cells of the central nervous system, resulting in oligodendrocyte death.” Bacterial “Relapses” The type B bacteria, once settled in the gut, goes through growth cycles followed by periods of dormancy. Since the toxin is only emitted during active periods, it is not always present in the bloodstream. Researchers are intrigued by this cyclical activity and hope to investigate whether these growth cycles coincide with relapses in people with relapsing-remitting forms of MS. “We are working on that now and need funding to push this project faster,” said Vartanian. The findings of this small study are exciting, but must be replicated by other researchers. Could the immune response seen in MS patients in fact be caused by the body’s attempt to fight the toxin? According to the researchers, it’s possible....

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Laser Light Zaps Away Cocaine Addiction

Posted on Sep 28, 2013

Laser Light Zaps Away Cocaine Addiction

By stimulating one part of the brain with laser light, researchers at the National Institutes of Health (NIH) and the Ernest Gallo Clinic and Research Center at UC San Francisco (UCSF) have shown that they can wipe away addictive behavior in rats – or conversely turn non-addicted rats into compulsive cocaine seekers.  “When we turn on a laser light in the prelimbic region of the prefrontal cortex, the compulsive cocaine seeking is gone,” said Antonello Bonci, MD, scientific director of the intramural research program at the NIH’s National Institute on Drug Abuse (NIDA), where the work was done. Bonci is also an adjunct professor of neurology at UCSF and an adjunct professor at Johns Hopkins University. Described this week in the journal Nature, the new study demonstrates the central role the prefrontal cortex plays in compulsive cocaine addiction. It also suggests a new therapy that could be tested immediately in humans, said Billy Chen of NIDA, the lead author of the study. Any new human therapy would not be based on using lasers, but would most likely rely on electromagnetic stimulation outside the scalp, in particular a technique called transcranial magnetic stimulation (TMS). Clinical trials are now being designed to test whether this approach works, Chen added. The High Cost of Cocaine Abuse Cocaine abuse is a major public health problem in the United States today, and it places a heavy toll on society in terms of lost job productivity, lost earnings, cocaine-related crime, incarcerations, investigations, and treatment and prevention programs. Antonello Bonci, MD The human toll is even greater, with an estimated 1.4 million Americans addicted to the drug. It is frequently the cause of emergency room visits – 482,188 in 2008 alone – and it is a top cause of heart attacks and strokes for people under 35. One of the hallmarks of cocaine addiction is compulsive drug taking – the loss of ability to refrain from taking the drug even if it’s destroying one’s life. What makes the new work so promising, said Bonci, is that Chen and his colleagues were working with an animal model that mimics this sort of compulsive cocaine addiction. The animals, like human addicts, are more likely to make bad decisions and take cocaine even when they are conditioned to expect self-harm associated with it. Electrophysiological studies involving these rats have shown that they have extremely low activity in the prefrontal cortex – a brain region fundamental for impulse control, decision making and behavioral flexibility. Similar studies that imaged the brains of humans have shown the same pattern of low activity in this region in people who are compulsively addicted to cocaine. Altering Brain Activity with a Laser To test whether altering the activity in this brain region could impact addiction, Chen and his colleagues employed a technique called optogenetics to shut the activity on and off using a laser. First they took light-sensitive proteins called rhodopsins and used genetic engineering to insert them into neurons in the rat’s prefrontal cortex. Activating this region with a laser tuned to the rhodopsins turned the nerve cells on and off. Turning on these cells wiped out the compulsive behavior, while switching them off turned the non-addicted ones into addicted, researchers found. What’s exciting, said Bonci, is that there is a way to induce a similar activation of the prelimbic cortex in people through a technique called transcranial magnetic stimulation (TMS), which applies an external electromagnetic field to the brain and has been used as a treatment for symptoms of depression. Bonci and his colleagues plan to begin clinical trials at NIH in which...

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Jeffrey Smith interviews Dr. Stephanie Seneff about Glyphosate

Posted on Sep 24, 2013

Jeffrey Smith interviews Dr. Stephanie Seneff about Glyphosate

This is an amazing, technical interview about the dangers of Roundup with Dr. Stephanie Seneff, one of the smartest scientists we know. In case you don’t have time to watch, here’s a synopsis, by Becca, over at Wyebrook Farm.

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