Dr Tiago Fleming Outeiro describes how his group is slowly uncovering the molecular basis of Parkinson's disease by studying the associated human protein in yeast cells.
Parkinson's disease is a neurodegenerative disorder without any known cure that affects around 6 million people worldwide. The symptoms, which include rigidity, difficulty in initiating movements and resting tremors, are all related to the specific death of dopamine-producing neurons in the brain. These neurons characteristically contain protein deposits, known as Lewy bodies. A small protein called alpha-synuclein is the main component of these deposits.
Dr Outeiro explains how baker's yeast, Saccharomyces cerevisiae, is helping researchers learn how alpha-synuclein might lead to Parkinson's disease. "Yeast is a very simple but powerful model in which to study how alpha-synuclein actually works as, remarkably, many of the biochemical pathways involved are similar between yeast and humans," he said. "There is still a lot we don't know about the function of this protein, but we do know that even small increases in the level of alpha-synuclein in cells lead to cell death."
Dr Outeiro and colleagues screened a library of 115,000 small compounds to try and identify those that are able to block the toxic effects of alpha-synuclein. Several of these molecules have proved effective in preventing Parkinson's disease in worms and blocking alpha-synuclein toxicity in rat neurons. If developed further, they could form the basis of future Parkinson's disease treatments.
New treatments for neurodegenerative diseases are urgently needed. "With the ageing of the human population the number of people affected by Parkinson's disease will continue to increase. This means the disease will become an even greater problem for modern societies due to the tremendous socio-economic costs associated," Dr Outeiro said. "It's therefore imperative that treatments for such neurodegenerative diseases are developed. Our studies in yeast have enabled us make a step towards this."
Showing posts with label neurology. Show all posts
Showing posts with label neurology. Show all posts
Sunday, September 12, 2010
Thursday, August 12, 2010
UC Parkinson's treatment shows promise
BY PEGGY O'FARRELL
Every morning, from about 8:30 to 10, Dan Truesdale froze up.
His muscles grew rigid, locked in place because of Parkinson's disease, until the medication finally kicked in, allowing to him get up, move around, live his life.
That changed last year when Truesdale, 47, became the first patient in Ohio to receive an experimental drug delivery system that gives his body a continual dose of the medication that lets him control his muscle movements.
His "frozen" muscles have thawed, Truesdale said.
"It's the best thing that's happened to me since I discovered I had Parkinson's," he said.
Researchers at the University of Cincinnati's Neuroscience Institute at University Hospital are recruiting more patients like Truesdale to test the system as part of a national phase 3 clinical trial.
Phase 3 trials are large-scale tests of new drugs or devices and the final step before federal health regulators decide to allow manufacturers to put new therapies on the market. Earlier phases test safety and effectiveness of new therapies on smaller scales.
Parkinson's disease is a chronic brain disorder in which brain cells that make the chemical dopamine die off. It usually strikes people over 50, and men are about 50 percent more likely to get it than women.
Without dopamine, adults lose control of muscle movements and balance. Symptoms get worse over time, said Alberto Espay, the neurologist heading up UC's arm of the trial, and Parkinson's patients may eventually lose the ability to speak, feed themselves, swallow or chew.
Replacing the lost dopamine helps patients regain muscle control, but standard treatments give dopamine in oral medications taken in several doses throughout the day.
That means the brain gets the dopamine it needs in interrupted allotments, so patients have periods throughout the day where they either can't move at all or they can't stop their bodies from moving involuntarily.
The drug delivery system Espay is testing aims to change that.
Abbott Pharmaceuticals' Levodopa-Carbidopa Intestinal Gel treatment system feeds the medication levodopa, which in the body becomes dopamine, into the upper intestine via a small tube surgically placed directly into the duodenum, or the very tip of the small intestine. The drug is fed through the tube from a cassette worn on the patient's body. A programmable pump lets the patient or doctor adjust the rate at which the medication is delivered.
"With this system, we're basically bathing the patient in dopamine at all times," Espay said.
Truesdale of Maineville used to be able to set his watch by his symptoms. The pump has changed all that. "I don't notice the passing of the hours because my symptoms have been reduced so drastically," he said.
He was diagnosed with Parkinson's in 2000, and has been on disability for the last four years. He recently began studying to become a minister.
The pump system is designed for patients like Truesdale with severe symptoms that are no longer controlled by standard medications, Espay said.
"People who've withdrawn from social and intellectual activities, they can resume them. We've seen people take up new activities after they've gone on the pump," he said.
Every morning, from about 8:30 to 10, Dan Truesdale froze up.
His muscles grew rigid, locked in place because of Parkinson's disease, until the medication finally kicked in, allowing to him get up, move around, live his life.
That changed last year when Truesdale, 47, became the first patient in Ohio to receive an experimental drug delivery system that gives his body a continual dose of the medication that lets him control his muscle movements.
His "frozen" muscles have thawed, Truesdale said.
"It's the best thing that's happened to me since I discovered I had Parkinson's," he said.
Researchers at the University of Cincinnati's Neuroscience Institute at University Hospital are recruiting more patients like Truesdale to test the system as part of a national phase 3 clinical trial.
Phase 3 trials are large-scale tests of new drugs or devices and the final step before federal health regulators decide to allow manufacturers to put new therapies on the market. Earlier phases test safety and effectiveness of new therapies on smaller scales.
Parkinson's disease is a chronic brain disorder in which brain cells that make the chemical dopamine die off. It usually strikes people over 50, and men are about 50 percent more likely to get it than women.
Without dopamine, adults lose control of muscle movements and balance. Symptoms get worse over time, said Alberto Espay, the neurologist heading up UC's arm of the trial, and Parkinson's patients may eventually lose the ability to speak, feed themselves, swallow or chew.
Replacing the lost dopamine helps patients regain muscle control, but standard treatments give dopamine in oral medications taken in several doses throughout the day.
That means the brain gets the dopamine it needs in interrupted allotments, so patients have periods throughout the day where they either can't move at all or they can't stop their bodies from moving involuntarily.
The drug delivery system Espay is testing aims to change that.
Abbott Pharmaceuticals' Levodopa-Carbidopa Intestinal Gel treatment system feeds the medication levodopa, which in the body becomes dopamine, into the upper intestine via a small tube surgically placed directly into the duodenum, or the very tip of the small intestine. The drug is fed through the tube from a cassette worn on the patient's body. A programmable pump lets the patient or doctor adjust the rate at which the medication is delivered.
"With this system, we're basically bathing the patient in dopamine at all times," Espay said.
Truesdale of Maineville used to be able to set his watch by his symptoms. The pump has changed all that. "I don't notice the passing of the hours because my symptoms have been reduced so drastically," he said.
He was diagnosed with Parkinson's in 2000, and has been on disability for the last four years. He recently began studying to become a minister.
The pump system is designed for patients like Truesdale with severe symptoms that are no longer controlled by standard medications, Espay said.
"People who've withdrawn from social and intellectual activities, they can resume them. We've seen people take up new activities after they've gone on the pump," he said.
Parkinson's Disease Placebo Response Increases with Expectations
Individuals with Parkinson's disease were more likely to have a neurochemical response to a placebo medication if they were told they had higher odds of receiving an active drug.
Chicago, IL - infoZine - "The promise of symptom improvement that is elicited by a placebo is a powerful modulator of brain neurochemistry," the authors write as background information to a report in the August issue of Archives of General Psychiatry, one of the JAMA/Archives journals. "Understanding the factors that modify the strength of the placebo effect is of major clinical as well as fundamental scientific significance." In patients with Parkinson's disease, the expectation of symptom improvement is associated with the release of the neurotransmitter dopamine, and the manipulation of this expectation has been shown to affect the motor performance of patients with the condition.
Sarah C. Lidstone, Ph.D., of Pacific Parkinson's Research Centre at Vancouver Coastal Health and the University of British Columbia, Vancouver, Canada, and colleagues studied 35 patients with mild to moderate Parkinson's disease undergoing treatment with the medication levodopa. On the first day of the study, a baseline positron emission tomographic (PET) scan was performed, participants were given levodopa and a second scan was performed one hour later to assess dopamine response. On the second day, patients were randomly assigned to one of four groups, during which they were told they had either a 25-percent, 50-percent, 75-percent or 100-percent chance of receiving active medication before the third scan; however, all patients were given placebo.
Patients who were told they had a 75-percent chance of receiving active medication demonstrated a significant release of dopamine in response to the placebo, whereas those in the other groups did not.
Patients' reactions to the active medication before the first scan was also correlated with their response to placebo. "Importantly, whereas prior medication experience (i.e., the dopaminergic response to levodopa) was the major determinant of dopamine release in the dorsal striatum, expectation of clinical improvement (i.e., the probability determined by group allocation) was additionally required to drive dopamine release in the ventral striatum," the authors write. Both areas have been shown to be involved with reward processing; in patients with a chronic debilitating illness who have responded to therapy in the past, expectation of therapeutic benefit in response to placebo has been likened to the expectation of receiving a reward.
"Our findings may have important implications for the design of clinical trials, as we have shown that both the probability of receiving active treatment—which varies in clinical trials depending on the study design and the information provided to the patient—as well as the treatment history of the patient influence dopamine system activity and consequently clinical outcome," the authors conclude. "While our finding of a biochemical placebo response restricted to a 75 percent likelihood of receiving active treatment may not generalize to diseases other than Parkinson's disease, it is extremely likely that both probability and prior experience have similarly profound effects in those conditions."
This study was funded by the Michael Smith Foundation for Health Research, the Canadian Institutes for Health Research and a TRIUMF Life Sciences Grant. Dr. Stoessl is supported by the Canada Research Chairs Program.
Chicago, IL - infoZine - "The promise of symptom improvement that is elicited by a placebo is a powerful modulator of brain neurochemistry," the authors write as background information to a report in the August issue of Archives of General Psychiatry, one of the JAMA/Archives journals. "Understanding the factors that modify the strength of the placebo effect is of major clinical as well as fundamental scientific significance." In patients with Parkinson's disease, the expectation of symptom improvement is associated with the release of the neurotransmitter dopamine, and the manipulation of this expectation has been shown to affect the motor performance of patients with the condition.
Sarah C. Lidstone, Ph.D., of Pacific Parkinson's Research Centre at Vancouver Coastal Health and the University of British Columbia, Vancouver, Canada, and colleagues studied 35 patients with mild to moderate Parkinson's disease undergoing treatment with the medication levodopa. On the first day of the study, a baseline positron emission tomographic (PET) scan was performed, participants were given levodopa and a second scan was performed one hour later to assess dopamine response. On the second day, patients were randomly assigned to one of four groups, during which they were told they had either a 25-percent, 50-percent, 75-percent or 100-percent chance of receiving active medication before the third scan; however, all patients were given placebo.
Patients who were told they had a 75-percent chance of receiving active medication demonstrated a significant release of dopamine in response to the placebo, whereas those in the other groups did not.
Patients' reactions to the active medication before the first scan was also correlated with their response to placebo. "Importantly, whereas prior medication experience (i.e., the dopaminergic response to levodopa) was the major determinant of dopamine release in the dorsal striatum, expectation of clinical improvement (i.e., the probability determined by group allocation) was additionally required to drive dopamine release in the ventral striatum," the authors write. Both areas have been shown to be involved with reward processing; in patients with a chronic debilitating illness who have responded to therapy in the past, expectation of therapeutic benefit in response to placebo has been likened to the expectation of receiving a reward.
"Our findings may have important implications for the design of clinical trials, as we have shown that both the probability of receiving active treatment—which varies in clinical trials depending on the study design and the information provided to the patient—as well as the treatment history of the patient influence dopamine system activity and consequently clinical outcome," the authors conclude. "While our finding of a biochemical placebo response restricted to a 75 percent likelihood of receiving active treatment may not generalize to diseases other than Parkinson's disease, it is extremely likely that both probability and prior experience have similarly profound effects in those conditions."
This study was funded by the Michael Smith Foundation for Health Research, the Canadian Institutes for Health Research and a TRIUMF Life Sciences Grant. Dr. Stoessl is supported by the Canada Research Chairs Program.
Saturday, July 24, 2010
UCSF Gene Therapy Method Allays Parkinson’s Symptoms
by Lauren Hammit
A novel technique created at UCSF to deliver a growth factor directly to brain cells has shown promising results in treating Parkinson’s symptoms and could enter human clinical trials as early as next year.
The technique is part of an experimental treatment called gene therapy, which is considered a hopeful medical advance for neurodegenerative diseases such as Parkinson’s. Gene therapy involves introducing genetic material into a cell to cause the expression of a particular protein that can replace a missing or defective protein responsible for disease.
The UCSF team demonstrated for the first time that the infusion system they designed successfully spread a targeted protein to critical regions in the primate brain. This resulted, on average, in a 50 percent improvement of symptoms that continued out to two years.
“The approach is among the first shown to be beneficial to animals after they have already developed signs of Parkinson’s,” said Krystof Bankiewicz, MD, PhD, Kinetics Foundation Chair in Translational Research and professor of Neurological Surgery at UCSF. “Our ultimate goal is to reverse this disease in patients, and we hope this method will enable doctors to do exactly that.”
Findings are published online and in the July 14, 2010, issue of the Journal of Neuroscience.
In addition to an improvement in Parkinson’s symptoms, the treated animals also maintained a higher density of neurons that produce the brain chemical dopamine – the same neurons that disappear in Parkinson’s disease. Live imaging of the brain by positron emission tomography (PET) scanning, which has been used to gauge treatment effects in clinical studies of Parkinson’s, showed that those neurons remained active.
“The scans enabled us to see where the protein went – and just as hoped, it had been taken up by neurons and transported along nerve fibers to where it was needed, the substantia nigra.” Bankiewicz said. Parkinson’s disease attacks the substantia nigra, which is a part of the brain that controls movement.
A clinical trial is planned to test the safety of the method, according to the National Institutes of Neurological Disorders and Stroke, which funded this research. In a workup for the trial, the National Institutes of Health Rapid Access to Interventional Development (NIH RAID) program is supporting additional toxicity studies, as well as the production of clinical grade virus.
A novel technique created at UCSF to deliver a growth factor directly to brain cells has shown promising results in treating Parkinson’s symptoms and could enter human clinical trials as early as next year.
The technique is part of an experimental treatment called gene therapy, which is considered a hopeful medical advance for neurodegenerative diseases such as Parkinson’s. Gene therapy involves introducing genetic material into a cell to cause the expression of a particular protein that can replace a missing or defective protein responsible for disease.
The UCSF team demonstrated for the first time that the infusion system they designed successfully spread a targeted protein to critical regions in the primate brain. This resulted, on average, in a 50 percent improvement of symptoms that continued out to two years.
“The approach is among the first shown to be beneficial to animals after they have already developed signs of Parkinson’s,” said Krystof Bankiewicz, MD, PhD, Kinetics Foundation Chair in Translational Research and professor of Neurological Surgery at UCSF. “Our ultimate goal is to reverse this disease in patients, and we hope this method will enable doctors to do exactly that.”
Findings are published online and in the July 14, 2010, issue of the Journal of Neuroscience.
In addition to an improvement in Parkinson’s symptoms, the treated animals also maintained a higher density of neurons that produce the brain chemical dopamine – the same neurons that disappear in Parkinson’s disease. Live imaging of the brain by positron emission tomography (PET) scanning, which has been used to gauge treatment effects in clinical studies of Parkinson’s, showed that those neurons remained active.
“The scans enabled us to see where the protein went – and just as hoped, it had been taken up by neurons and transported along nerve fibers to where it was needed, the substantia nigra.” Bankiewicz said. Parkinson’s disease attacks the substantia nigra, which is a part of the brain that controls movement.
A clinical trial is planned to test the safety of the method, according to the National Institutes of Neurological Disorders and Stroke, which funded this research. In a workup for the trial, the National Institutes of Health Rapid Access to Interventional Development (NIH RAID) program is supporting additional toxicity studies, as well as the production of clinical grade virus.
Tuesday, June 22, 2010
Report: Spine Stimulation May Benefit Parkinson’s Disease Patients
By Steven Marsh
Patients who have been diagnosed with Parkinson’s disease (PD) may have relief from symptoms associated with the condition in the near future, according to a study presented at the 2010 American Society for Stereotactical and Functional Neurosurgery.
In an effort to find potential treatments for individuals with the nervous system disorder, a team of researchers at Rhode Island Hospital conducted a series of exercises that stimulated the spinal cord on an animal model, which showed signs of PD. Because the findings displayed better motor function in the animal, the investigators tested the treatment with spinal cord simulation on a male patient aged 82 years.
While the individual wasn’t receiving any form of medication as treatment for the disorder, researchers used different frequencies of stimulation to determine if a human would experience similar results compared to the animal model.
The researchers discovered that high stimulation frequencies made it easier for the patient to walk, while low frequencies worsened PD side effects.
While the results of the study did give investigators some insight as to how to treat PD patients, clinical trials with a larger group of patients would be more beneficial to developing treatment.
Finding therapies for this disorder is growing in interest throughout the medical world, as QR Pharma and Massachusetts General Hospital have launched research to determine a way to block a protein associated the development of PD.ADNFCR-1960-ID-19845071-ADNFCR
Patients who have been diagnosed with Parkinson’s disease (PD) may have relief from symptoms associated with the condition in the near future, according to a study presented at the 2010 American Society for Stereotactical and Functional Neurosurgery.
In an effort to find potential treatments for individuals with the nervous system disorder, a team of researchers at Rhode Island Hospital conducted a series of exercises that stimulated the spinal cord on an animal model, which showed signs of PD. Because the findings displayed better motor function in the animal, the investigators tested the treatment with spinal cord simulation on a male patient aged 82 years.
While the individual wasn’t receiving any form of medication as treatment for the disorder, researchers used different frequencies of stimulation to determine if a human would experience similar results compared to the animal model.
The researchers discovered that high stimulation frequencies made it easier for the patient to walk, while low frequencies worsened PD side effects.
While the results of the study did give investigators some insight as to how to treat PD patients, clinical trials with a larger group of patients would be more beneficial to developing treatment.
Finding therapies for this disorder is growing in interest throughout the medical world, as QR Pharma and Massachusetts General Hospital have launched research to determine a way to block a protein associated the development of PD.ADNFCR-1960-ID-19845071-ADNFCR
Tuesday, May 4, 2010
Singapore scientists develop zebrafish model for studying Parkinson's Disease
Singapore scientists develop zebrafish model for studying Parkinson's Disease
Scientists at the Genome Institute of Singapore (GIS), a biomedical research institute of the Agency for Science, Technology and Research (A*STAR), have recently developed a zebrafish model for Parkinson's disease that can be used for understanding the mechanism underlying its development. The knowledge gained will be helpful for future screening of new drugs to treat Parkinson's disease (PD).
This study describes the first zebrafish model for LRRK2 mutation-related PD. It is able to overcome some limitations of other animal models of LRRK2 and demonstrates that zebrafish, a tropical freshwater fish that can often be found in aquariums, can be used to study the development of human diseases. Led by GIS Group Leader Dr Liu Jianjun, the finding was published in PLoS Genetics on April 22, 2010.
To explore the biological functions of LRRK2, the scientists studied this gene in zebrafish by blocking its normal function. This resulted in Parkinsonism-like phenotypes in zebrafish, including locomotive defects and loss of neurons, similar to those of PD patients. It was found from the study that the defects of the fish can be rescued by expressing the normal protein of LRRK2. Significantly, the administration of Levo-dopa (L-dopa), a compound that is widely used to treat PD, can also rescue the locomotive defects caused by the modification of the zebrafish LRRK2 protein.
Parkinson's disease (PD) is a degenerative disease of the brain that often impairs motor skills, speech and other functions. The discovery of several gene mutations in affected patients clearly demonstrated the involvement of genetic factors in the development of PD. LRRK2 was discovered from previous studies by the same team of researchers to be one of the most important genetic causes of PD in the Asian population.
"This work shows how the use of a simple model system in fish can help decipher the root causes of a serious human disorder like Parkinson's disease, " said Professor Edison Liu, Executive Director of the GIS.
Dr Lim Kah Leong, Associate Professor of the National Neuroscience Institute and Duke-NUS Graduate Medical School, added "This novel and elegant study has illuminated the role of an otherwise poorly understood but important domain of LRRK2 that is associated with an increased risk for Parkinson's disease amongst Asian populations. The use of zebrafish as a disease model is a clever approach. I am definitely pleased to note that our arsenal of experimental organisms for drug screening has expanded with this study."
The zebrafish model derived from this study serves as a vertebrate model suitable for large-scale drug screening and provides a good disease model for PD. Using a novel technology known as the Zinc-finger nucleases (ZFNs), further research is being carried out to generate additional mutations of zebrafish LRRK2 gene. Such mutated zebrafishes can be used for advancing investigation for the biological mechanism of PD and screening of new drugs for PD treatment.
More information: The research findings can be found in the April 22, 2010 print issue of PLoS GENETICS under the title "Deletion of the WD40 Domain of LRRK2 in Zebrafish Causes Parkinsonism-Like Loss of Neurons and Locomotive Defect".
Provided by Agency for Science, Technology and Research (A*STAR)
Scientists at the Genome Institute of Singapore (GIS), a biomedical research institute of the Agency for Science, Technology and Research (A*STAR), have recently developed a zebrafish model for Parkinson's disease that can be used for understanding the mechanism underlying its development. The knowledge gained will be helpful for future screening of new drugs to treat Parkinson's disease (PD).
This study describes the first zebrafish model for LRRK2 mutation-related PD. It is able to overcome some limitations of other animal models of LRRK2 and demonstrates that zebrafish, a tropical freshwater fish that can often be found in aquariums, can be used to study the development of human diseases. Led by GIS Group Leader Dr Liu Jianjun, the finding was published in PLoS Genetics on April 22, 2010.
To explore the biological functions of LRRK2, the scientists studied this gene in zebrafish by blocking its normal function. This resulted in Parkinsonism-like phenotypes in zebrafish, including locomotive defects and loss of neurons, similar to those of PD patients. It was found from the study that the defects of the fish can be rescued by expressing the normal protein of LRRK2. Significantly, the administration of Levo-dopa (L-dopa), a compound that is widely used to treat PD, can also rescue the locomotive defects caused by the modification of the zebrafish LRRK2 protein.
Parkinson's disease (PD) is a degenerative disease of the brain that often impairs motor skills, speech and other functions. The discovery of several gene mutations in affected patients clearly demonstrated the involvement of genetic factors in the development of PD. LRRK2 was discovered from previous studies by the same team of researchers to be one of the most important genetic causes of PD in the Asian population.
"This work shows how the use of a simple model system in fish can help decipher the root causes of a serious human disorder like Parkinson's disease, " said Professor Edison Liu, Executive Director of the GIS.
Dr Lim Kah Leong, Associate Professor of the National Neuroscience Institute and Duke-NUS Graduate Medical School, added "This novel and elegant study has illuminated the role of an otherwise poorly understood but important domain of LRRK2 that is associated with an increased risk for Parkinson's disease amongst Asian populations. The use of zebrafish as a disease model is a clever approach. I am definitely pleased to note that our arsenal of experimental organisms for drug screening has expanded with this study."
The zebrafish model derived from this study serves as a vertebrate model suitable for large-scale drug screening and provides a good disease model for PD. Using a novel technology known as the Zinc-finger nucleases (ZFNs), further research is being carried out to generate additional mutations of zebrafish LRRK2 gene. Such mutated zebrafishes can be used for advancing investigation for the biological mechanism of PD and screening of new drugs for PD treatment.
More information: The research findings can be found in the April 22, 2010 print issue of PLoS GENETICS under the title "Deletion of the WD40 Domain of LRRK2 in Zebrafish Causes Parkinsonism-Like Loss of Neurons and Locomotive Defect".
Provided by Agency for Science, Technology and Research (A*STAR)
Sunday, February 21, 2010
Placebo treatments stronger than doctors thought
By MARIA CHENG AP Medical Writer © 2010 The Associated Press
LONDON — When it comes to the placebo effect, it really may be mind over matter, a new analysis suggests.
In a review of recent research, international experts say there is increasing evidence that fake treatments, or placebos, have an actual biological effect in the body.
The doctor-patient relationship, plus the expectation of recovery, may sometimes be enough to change a patient's brain, body and behavior, experts write. The review of previous research on placebos was published online Friday in Lancet, the British medical journal.
"It's not that placebos or inert substances help," said Linda Blair, a Bath-based psychologist and spokeswoman for the British Psychological Society. Blair was not linked to the research. "It's that people's belief in inert substances help."
While doctors have long recognized that placebos can help patients feel better, they weren't sure if the treatments sparked any physical changes.
In the Lancet review, researchers cite studies where patients with Parkinson's disease were given dummy pills. That led their brains to release dopamine, a feel-good chemical, and also resulted in other changes in brain activity.
"When you think you're going to get a drug that helps, your brain reacts as if it's getting relief," said Walter Brown, a clinical professor of psychiatry at Brown and Tufts University. "But we don't know how that thought that you're going to get better actually translates into something happening in the brain."
With growing proof that placebos work, some doctors are trying to figure out how to capitalize on their effects, without being unethical.
Blair said that to be completely honest with patients — to tell them they were receiving a fake treatment — would sabotage their belief in the drug, and thus, undermine any potential benefit.
But Brown didn't agree. For certain patients, like those with mild depression or anxiety, he said placebos were likely to work just as well as established therapies.
He said that even if doctors acknowledge they are giving such patients a placebo medication, but say it could be beneficial, "it might just actually work."
LONDON — When it comes to the placebo effect, it really may be mind over matter, a new analysis suggests.
In a review of recent research, international experts say there is increasing evidence that fake treatments, or placebos, have an actual biological effect in the body.
The doctor-patient relationship, plus the expectation of recovery, may sometimes be enough to change a patient's brain, body and behavior, experts write. The review of previous research on placebos was published online Friday in Lancet, the British medical journal.
"It's not that placebos or inert substances help," said Linda Blair, a Bath-based psychologist and spokeswoman for the British Psychological Society. Blair was not linked to the research. "It's that people's belief in inert substances help."
While doctors have long recognized that placebos can help patients feel better, they weren't sure if the treatments sparked any physical changes.
In the Lancet review, researchers cite studies where patients with Parkinson's disease were given dummy pills. That led their brains to release dopamine, a feel-good chemical, and also resulted in other changes in brain activity.
"When you think you're going to get a drug that helps, your brain reacts as if it's getting relief," said Walter Brown, a clinical professor of psychiatry at Brown and Tufts University. "But we don't know how that thought that you're going to get better actually translates into something happening in the brain."
With growing proof that placebos work, some doctors are trying to figure out how to capitalize on their effects, without being unethical.
Blair said that to be completely honest with patients — to tell them they were receiving a fake treatment — would sabotage their belief in the drug, and thus, undermine any potential benefit.
But Brown didn't agree. For certain patients, like those with mild depression or anxiety, he said placebos were likely to work just as well as established therapies.
He said that even if doctors acknowledge they are giving such patients a placebo medication, but say it could be beneficial, "it might just actually work."
Monday, July 20, 2009
Initial treatment for Parkinson's disease
No known treatment can stop or reverse the breakdown of nerve cells that causes Parkinson's disease. However, drugs can relieve many symptoms of the disease. Surgery also can be effective in a small number of people to treat symptoms of Parkinson's disease.
Treatment is different for every person, and the type of treatment you will need may change as the disease progresses. Your age, work status, family, and living situation can all affect decisions about when to begin treatment, what types of treatment to use, and when to make changes in treatment. As your medical condition changes, you may need regular adjustments in your treatment to balance quality-of-life issues, side effects of treatment, and treatment costs.
Parkinson's disease causes a wide range of symptoms and complications. This topic covers the overall management of the disease. This topic does not discuss managing specific symptoms.
Initial treatment
If your symptoms are mild, you may not need treatment for Parkinson's disease. Your doctor may wait to prescribe treatment with drugs until your symptoms begin to interfere with your daily activities. Additional treatment methods (such as exercise, physical therapy, and occupational therapy) can be helpful at all stages of Parkinson's disease to help you maintain your strength, mobility, and independence.
If you do need drugs at this point, there are several options. Levodopa is considered the "gold standard" of treatment for Parkinson's disease. But levodopa can have negative effects when used long-term. Because of this, dopamine agonists such as pramipexole and ropinirole often are used first. Other non-dopamine drugs may be used early in the course of the disease. These include amantadine, monoamine oxidase inhibitors (such as selegiline), and anticholinergics (such as trihexyphenidyl). As the disease progresses, levodopa will likely need to be added.
Early in the disease, it might be helpful to take pills with food to help with nausea, which may be caused by some medicines taken for Parkinson's disease. Later in the disease, taking the medicines at least one hour before meals (and at least two hours after meals) may help them work better.
Your doctor, other health professionals, or Parkinson's disease support groups can help you get emotional support and education about the illness. This is important both early and throughout the course of the disease.
Ongoing treatment
As Parkinson's disease progresses, the symptoms usually become more disabling. Most people develop mild to moderate tremor. Movement is often slow and limited due to muscular rigidity and the slowing down and loss of automatic and spontaneous movement (bradykinesia). Treatment in this stage is determined by weighing the severity of the symptoms against the side effects of drugs.
The symptoms of Parkinson's disease change as the disease progresses. Because of this, your doctor will adjust your drugs to deal with the symptoms as they appear. Levodopa is the most commonly used drug for Parkinson's disease. However, it may cause side effects with prolonged use or high dosages. Your doctor may prescribe dopamine agonists such as pramipexole or ropinirole to delay the point at which you need to begin taking levodopa. Studies have suggested that this may delay the onset of levodopa's side effects.234 Your doctor may also prescribe levodopa along with a dopamine agonist.
Treatment is different for every person, and the type of treatment you will need may change as the disease progresses. Your age, work status, family, and living situation can all affect decisions about when to begin treatment, what types of treatment to use, and when to make changes in treatment. As your medical condition changes, you may need regular adjustments in your treatment to balance quality-of-life issues, side effects of treatment, and treatment costs.
Parkinson's disease causes a wide range of symptoms and complications. This topic covers the overall management of the disease. This topic does not discuss managing specific symptoms.
Initial treatment
If your symptoms are mild, you may not need treatment for Parkinson's disease. Your doctor may wait to prescribe treatment with drugs until your symptoms begin to interfere with your daily activities. Additional treatment methods (such as exercise, physical therapy, and occupational therapy) can be helpful at all stages of Parkinson's disease to help you maintain your strength, mobility, and independence.
If you do need drugs at this point, there are several options. Levodopa is considered the "gold standard" of treatment for Parkinson's disease. But levodopa can have negative effects when used long-term. Because of this, dopamine agonists such as pramipexole and ropinirole often are used first. Other non-dopamine drugs may be used early in the course of the disease. These include amantadine, monoamine oxidase inhibitors (such as selegiline), and anticholinergics (such as trihexyphenidyl). As the disease progresses, levodopa will likely need to be added.
Early in the disease, it might be helpful to take pills with food to help with nausea, which may be caused by some medicines taken for Parkinson's disease. Later in the disease, taking the medicines at least one hour before meals (and at least two hours after meals) may help them work better.
Your doctor, other health professionals, or Parkinson's disease support groups can help you get emotional support and education about the illness. This is important both early and throughout the course of the disease.
Ongoing treatment
As Parkinson's disease progresses, the symptoms usually become more disabling. Most people develop mild to moderate tremor. Movement is often slow and limited due to muscular rigidity and the slowing down and loss of automatic and spontaneous movement (bradykinesia). Treatment in this stage is determined by weighing the severity of the symptoms against the side effects of drugs.
The symptoms of Parkinson's disease change as the disease progresses. Because of this, your doctor will adjust your drugs to deal with the symptoms as they appear. Levodopa is the most commonly used drug for Parkinson's disease. However, it may cause side effects with prolonged use or high dosages. Your doctor may prescribe dopamine agonists such as pramipexole or ropinirole to delay the point at which you need to begin taking levodopa. Studies have suggested that this may delay the onset of levodopa's side effects.234 Your doctor may also prescribe levodopa along with a dopamine agonist.
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