Saturday, August 18, 2007

New Research Shows How Chronic Stress Worsens Neurodegenerative Disease Course

Newswise — The evidence is accumulating on how bad stress is for health. Chronic stress can intensify inflammation and increase a person’s risk for developing central nervous system infections, neurodegenerative diseases, like multiple sclerosis (MS), and other inflammatory diseases, say researchers presenting at the 115th Annual Convention of the American Psychological Association (APA). These researchers have demonstrated for the first time that stress-related increases in central nervous system inflammation are behind the adverse effects of stress in an animal model of MS.
Researchers from Texas A & M University used mice to show what role social stress plays in the immune process to influence the course of an MS-like disease. They proposed that stress-induced increases of pro-inflammatory cytokines, which are proteins that regulate immune and inflammatory functions, inhibit the clearing of a virus and allow the inflammatory process to run amok. Stress, say the authors, may interact with viral infections to increase vulnerabilityto diseases such as MS. Meta-analysis of studies investigating the impact of stressful events in patients with MS show an increased risk of worsening symptoms of the disease.
In a series of experiments on mice, the authors showed that increases in a particular cytokine – interleukin-6 (IL-6), which is released during stress and regulates the part of the immune system that fights infection – can make socially stressed mice vulnerable to MS-like illnesses.
The researchers used a social disruption model (SDR) to simulate social stress for mice and then infected the mice with Theiler’s murine encephalomyelitis (TMEV). Infection with TMEV results in an acute infection of the central nervous system followed by a chronic autoimmune disease similar to that seen in humans with MS. Their laboratory has previously shown that exposure to social stress prior to infection exacerbates both the early viral infection and the later autoimmune demyelinating MS-like phase of the disease.
To create a stressful environment, researchers housed three young male mice together for several weeks. After the mice established a stable social hierarchy, researchers introduced an older aggressive male into the residence for a couple of hours. The intruder exhibits aggressive behavior – posturing, fighting, wounding, pursuit – that results in submissive behaviors and social defeat in the younger resident mice. This procedure was repeated for three consecutive nightly two-hour sessions with one night off, followed by an additional three nightly sessions. To keep the mice from getting used to the intruder, a new intruder was introduced for each session.
What they found was this stress appears to elevate levels of IL-6, which subsequently increases the severity of the MS-like illness. Furthermore, using specific IL-6 neutralizing antibody treatments during the stress exposure can prevent the stress-related worsening of the disease, said the authors.
In one experiment, they showed that mice exposed to social disruption had elevated central and peripheral levels of IL-6. However, infusing the neutralizing antibody into the brain prevented this stress-induced increase in IL-6. This demonstrated that the antibody could effectively reverse the stress-related increases in IL-6 in brain and in circulating blood.
Results from a second experiment showed that administering the IL-6 neutralizing antibody during the stress exposure prevented worsening of the TMEV infection. By blocking the stress-induced elevation of IL-6, TMEV infection was weakened, which lessened some of the disease symptoms, such as motor impairment, inflammation in the brain and spinal cord, and the viral level in the central nervous system. Based on these findings, Dr. Mary Meagher, the lead researcher, proposes that the adverse effects of stress-induced IL-6 on TMEV infection are enough to create a pro-inflammatory environment that interferes with the immune response to infection. Because the early immune response shapes the later specific immune response to infection, impairment of the early response could account for the increased viral level, prolonged viral infection, increased CNS inflammation, and the subsequent exacerbation of the chronic autoimmune disease.
There is a growing body of evidence in both animal and human studies that suggests that exposure to stress can increase and sustain the release of pro-inflammatory cytokines following an assault on the immune system. Thus, the present findings might help scientists unravel which biobehavioral mechanisms offset the adverse health effects of chronic social stress in humans. “Similar to mice exposed to repeated social defeat by an aggressive intruder, people exposed to chronic social conflict experience high levels of stress and consequent dysregulation of the immune system, thereby increasing vulnerability to infectious and autoimmune disease,” said Meagher. “The cytokine response during chronic stress appears to play a key role in exacerbating the acute CNS infection and the development of subsequent autoimmune responses.”
Furthermore, interventions that prevented or reversed the stress-induced increases in IL-6 in the mouse model may have implications for humans, said Meagher. It is possible that the adverse effects of social conflict on people who are vulnerable to certain inflammatory diseases may be prevented or reversed by treatments aimed at blocking increases in this cytokine. Recent evidence suggests that some potential interventions include certain anti-inflammatory drugs, exercise, antidepressant medication, omega-3 fatty acids, and mindfulness relaxation training. However, human clinical trials are needed to fully evaluate this issue.
Presentation: “Severe or Traumatic Stress and Inflammation in Multiple Sclerosis,” Mary W. Meagher, PhD, Texas A&M University
Session 1157 – Symposium: Traumatic Stress, Cardiovascular Disease, Metabolic Syndrome, and Neurodegenerative Disease, 11:00 – 11:50 AM, Friday, August 17, Moscone Center, Second Floor-West Building, Room 2020
Full text of the article is available from the APA Public Affairs Office
The American Psychological Association (APA), in Washington, DC, is the largest scientific and professional organization representing psychology in the United States and is the world’s largest association of psychologists. APA’s membership includes more than 148,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting health, education and human welfare.

Wednesday, August 15, 2007

First human trial of DNA-based vaccine cheers MS researchers

First human trial of DNA-based vaccine cheers MS researchers
· Number and size of lesions drop sharply during tests · Scientists urge caution and call for further work
Ian Sample, science correspondent
The Guardian
Tuesday August 14 2007
The first human trial of a DNA-based vaccine to combat multiple sclerosis has been declared a success by doctors in America after tests on patients revealed signs that their condition had improved. However, the trial is only the first small step in developing an effective treatment against the debilitating degenerative disease, which affects about 85,000 people in the UK.
The vaccine works by dampening down the immune system, which is believed to become overactive in people who develop multiple sclerosis.
The disease is caused by a small group of immune cells that start to attack the body by targeting the fatty sheaths of myelin that coat nerves in the central nervous system. After waves of attacks, the nerves are eventually destroyed. The myelin coating helps to ensure that signals passed along the nerves travel quickly.
Doctors led by Amit Bar-Or at the Montreal Neurological Institute in Canada developed a vaccine which contains the strands of DNA that produce myelin.
In the trial, 30 patients had the vaccine injected into their muscles over one, three, five and nine weeks, with half also receiving a statin drug to boost the effect of the vaccine. The vaccine was administered at three different doses.
All of the patients in the study had the most common form of the disease, known as relapsing and remitting multiple sclerosis, in which symptoms come and go over long periods, or steadily worsen with spells of remission between.
The main purpose of the trial was to test the safety of the vaccine, the first to be tested in humans to treat an autoimmune disease such as MS.
Any side effects were brief and were considered to be mild or moderate, according to a report in the US journal Archives of Neurology.
The doctors went on to test blood from the patients to see how their immune systems had responded to the vaccine. They found that levels of immune cells that specifically attack myelin sheaths had fallen, along with levels of antibodies which are also implicated in the disease.
The doctors recorded eight relapses, though only one occurred in a patient who was receiving the experimental vaccine. After treatment, the patient continued on the trial and experienced no further relapses. All of the other relapses happened five to 29 weeks after the patients received their final dose of vaccine.
The patients were later given magnetic resonance imaging brain scans to examine the damage caused by the disease. As the disease progresses, it produces lesions which can be counted and measured. In the trial, the researchers saw the number of lesions fall by 18% to 64% in patients who were given the DNA vaccine alone. The size of the lesions also dropped, by between 38% and 83%. The statin drug did not seem to improve the vaccine's effectiveness.
The researchers were excited by the results, but cautioned against reading too much into the trial's findings. "We have demonstrated in this first, to our knowledge, in-human trial of a DNA vaccine for autoimmune disease that the approach is safe and well-tolerated. We describe evidence for induction of favourable trends on brain MRI, indicating a reduction in the inflammatory response in the central nervous system," they wrote.
The team has now begun a 12-month trial of 290 patients. If that is a success, it could pave the way for DNA vaccines for a range of other diseases caused by an over-active immune system, such as type I diabetes and rheumatoid arthritis.

Tuesday, August 14, 2007

DNA Vaccine Against Multiple Sclerosis Appears Safe, Potentially Beneficial

Newswise — A newly developed DNA vaccine appears safe and may produce beneficial changes in the brains and immune systems of individuals with multiple sclerosis, according to an article posted online today that will appear in the October 2007 print issue of Archives of Neurology, one of the JAMA/Archives journals.
In patients with multiple sclerosis (MS), the immune system attacks the myelin sheaths that protect nerve cells in the brain and spinal cord, according to background information in the article. The nerve cell’s axon, which transmits messages to other neurons, is eventually destroyed. The cause of MS is unknown, but evidence points to the involvement of immune cells and antibodies that recognize and attack specific substances in the myelin, such as myelin basic protein. Certain cytokines, small proteins produced by cells that trigger inflammation, also may play a role.
Amit Bar-Or, M.D., of the Montreal Neurological Institute and colleagues tested a DNA vaccine, BHT-3009, that encodes a full-length human myelin basic protein. Between 2004 and 2006, the researchers administered the vaccine to 30 patients with relapsing-remitting MS [characterized by symptomatic periods and periods of remission] or secondary progressive MS [when symptoms progressively worsen, but there still may be periods of remission]. After one, three, five and nine weeks, participants received intramuscular injections of placebo or BHT-3009 (in doses of .5 milligrams, 1.5 milligrams or 3 milligrams), with or without 80-milligram pills of atorvastatin calcium, a lipid-lowering drug previously shown to be effective in autoimmune conditions. After 13 weeks, participants who initially received placebo received four injections of BHT-3009.
Magnetic resonance imaging (MRI) and other safety evaluations were performed at the beginning of the study, and again after five, nine, 13, 26, 38 and 50 weeks. “BHT-3009 was safe and well tolerated, provided favorable trends on brain MRI and produced beneficial antigen-specific immune changes,” the authors write. These changes included a reduction in the number of cytokine-producing CD4+ T cells (a type of white blood cell) specifically targeting myelin proteins. This reduction was found in the blood as well as in the cerebrospinal fluid of three patients who voluntarily underwent lumbar puncture after completing the course of BHT-3009. Atorvastatin did not appear to provide additional benefit.
“There were no increases in clinical relapses, disability, drug-associated laboratory abnormalities, adverse events or the number and volume of contrast-enhancing [visible on MRI] lesions on brain MRI with BHT-3009 treatment compared with placebo,” the authors write. “In fact, there was a trend toward a decrease in the number and volume of contrast-enhancing lesions in the brain in patients treated with BHT-3009 compared with placebo.”
Based on these results, a phase 2b trial—a randomized clinical trial in approximately 290 patients—of BHT-3009 is already under way. “If successful in MS, antigen-specific DNA vaccines can be developed for prevention or treatment of related diseases, such as type 1 diabetes mellitus, systemic lupus erythematosus, rheumatoid arthritis and myasthenia gravis,” the authors conclude.(ArchNeurol. 2007;64(10):(doi:10.1001/archneur.64.10.nct70002). Available pre-embargo to the media at www.jamamedia.org.)
Editor’s Note: The work described in this article was funded by Bayhill Therapeutics, Inc. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
© 2007 Newswise. All Rights Reserved.

New Treatment Boosts Muscle Function in Myasthenia GravisNewswise — A new type of treatment significantly reduces the severity of muscle weakness in m

Newswise — A new type of treatment significantly reduces the severity of muscle weakness in myasthenia gravis (MG), giving hope for a new class of drugs to treat neurological disorders, according to a study published in the August 14, 2007, issue of Neurology®, the medical journal of the American Academy of Neurology.
The drug, oral EN101antisense, inhibits the production of acetylcholine esterase, which is an important enzyme in the function of the neuromuscular junction, where nerves connect with muscles. Antisense is a synthetic, short segment of DNA that locks onto a strand of mRNA and blocks production of specific proteins.
“This is the first time we’ve been able to show that antisense is effective and safe when taken orally for a neurological disease,” said study author Zohar Argov, MD, with Hadassah Hebrew University Medical Center in Jerusalem and member of the American Academy of Neurology. “Oral delivery of antisense has long been sought after since it is expected to improve patient compliance because daily injections won’t be needed.”
People with myasthenia gravis have increased fatigue and reduced strength in their voluntary muscles. Symptoms may also include a drooping eyelid, double vision, difficulty in swallowing, or slurred speech. Myasthenia gravis is believed to affect 20 out of every 100,000 people.
For the study, 16 people with myasthenia gravis were given daily doses of oral EN101 antisense for four days and monitored for one month. Four of the people later took the drug for a month. The study found that oral antisense reduced disease severity by an average of 46 percent, with patients experiencing improved muscle function, improved swallowing time and the disappearance of a drooping eyelid. Side effects reported during the study were dryness of eyes and mouth.
Experts say this discovery may have implications beyond myasthenia gravis. “Oral antisense may become another mode of therapy in neuromuscular disease and further study is needed,” said Argov. “However, these preliminary results should be evaluated with caution since this was an open label study.”
Argov says further research is underway to look at the effects of this drug over a longer period of time.
The study was supported by Ester Neuroscience Ltd., a biotechnology company.
The American Academy of Neurology, an association of more than 20,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as stroke, Alzheimer’s disease, epilepsy, Parkinson’s disease, and multiple sclerosis.
For more information about the American Academy of Neurology, visit http://www.aan.com.
© 2007 Newswise. All Rights Reserved.

Studies show that exposure to the airborne toxins generated by the WTC attacks triggered the development of sarcoidosis and sarcoidosis-like respirato

The death toll from 9/11 reached 2,750 when Felicia Dunn-Jones’s name was added to the official death list. An attorney, Dunn-Jones fled her office, located a block away from the towers, and died of sarcoidosis 5 months after the attack. Dust from exposure to Ground Zero has also directly contributed to the death of others not yet on the list such as James Zadroga, a 34-year old police officer. Of the 10,000 clients represented by attorney David Worby involved in a lawsuit accusing the city of negligence, 5 have recently died of sarcoidosis.
The confirmation of Dunn-Jone’s sarcoidosis came in a letter by Dr. Charles S. Hirsch, the city's Chief Medical Examiner on May 18 stating that "Accumulating evidence indicates that in some persons exposure to WTC dust has caused sarcoidosis or an inflammatory reaction indistinguishable from sarcoidosis.”
Chemical Dust Exposure and Sarcoidosis
Sarcoidosis, which is also known as Besnier-Boeck disease, is an autoimmune disorder that usually starts in the lungs or the lymph nodes of the chest cavity. Sarcoidosis of the thyroid gland can also develop. Since its identification in the 1860s, no direct cause of sarcoidosis had been identified.
Although airborne toxins had long been suspected, recent evidence confirms that toxins, such as those that clouded the World Trade Center, can trigger sarcoidosis. A pathologist for Ocean County, New Jersey concluded in April 2006 that the January 2006 death of James Zadroga was directly linked to 9/11 recovery operations.
Post WTC Sarcoidosis
As of May, 2007, twenty-six New York City Ground Zero firefighters and emergency medical service workers have developed evidence of a sarcoid-like granulomatous pulmonary disease. The condition, called World Trade Center sarcoid-like granulomatous pulmonary disease, consists of abnormalities in the pulmonary parenchyma, hilar and/or mediastinal adenopathies, clinical features resembling asthma, and, occasionally, involvement of the bones, joints, skin, or spleen.
Investigators had previously shown that even before 9/11, New York City firefighters and rescue personnel had an elevated incidence of sarcoidosis or sarcoid-like granulomatous disease linked to occupational or environmental exposures to organic dusts, metals, chemical dust, silica, and wood dust or smoke.
However, the incidence of sarcoidosis or sarcoid-like pulmonary disease increased significantly after 9/11 compared to the years before the World Trade Center dust exposure, particularly during the first 12 months following 9/11/2001.
The Proof
To determine whether prolonged, repeated exposure to airborne particulates might increase the risk of sarcoidosis or sarcoid-like granulomatous pulmonary disease in a population already at risk, the investigators followed fire department employees. Those with chest radiograph findings suggestive of sarcoidosis underwent additional evaluation using chest CT imaging, pulmonary function tests, airway challenge tests, and biopsies.
The investigators calculated an annual incidence rate of sarcoidosis and compared it with the 15 years before the World Trade Center attacks. They found that 26 patients, all at the World Trade Center site within 72 hours of the towers’ collapse, when particulate levels were highest, had evidence of new-onset sarcoidosis.
Conclusion
Studies of the 26 firefighters showed that 18 (69%) had findings that were consistent with asthma, and fifteen of these patients had clinical symptoms: cough, dyspnea, and/or wheeze exacerbated by exercise and/or irritant exposure, or improved by the use of bronchodilators. All patients had intrathoracic adenopathy, and six (23%) had extrathoracic disease, involving the spleen, abdominal and pelvic lymph nodes, bones, joints, skin, and, in one case, hematuria.
Half the patients were identified within the first year following exposure, indicating an annual incidence rate of 86 per 100,000. The remaining 13 patients were identified within the second to fifth years after 9/11, showing an annual incidence rate of 22 per 100,000.
The average annual incidence rate of sarcoidosis among firefighters during the 15 years before the World Trade Center attacks was 15/100,000, and among controls (rescue personnel without exposure to fire conditions) the rate was 12.9/100,000.
Resources
Carren Bersch, Zac’s Rocky Mountain High, From the Editor, Medical Laboratory Observer, August 2007, Vol 39 (8): 4.