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(Health) Stroke: New Compound Reduces Stroke Damage

 
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PostPosted: Tue May 16, 2006 5:47 am    Post subject: (Health) Stroke: New Compound Reduces Stroke Damage Reply with quote






American Society for Biochemistry and Molecular Biology
15 May 2006

New compound reduces stroke damage

Bethesda, MD – A group of German scientists has synthesized a new compound that dramatically decreases the damage to neurons in rats demonstrating stroke symptoms. The research appears as the "Paper of the Week" in the May 26 issue of the Journal of Biological Chemistry, an American Society for Biochemistry and Molecular Biology journal.
Stroke is the third leading cause of death in the United States and the most common cause of adult disability. An ischemic stroke occurs when a cerebral vessel occludes, obstructing blood flow to a portion of the brain. Currently, there is only one approved stroke therapy, tissue plasminogen activator, which targets the thrombus within the blood vessel. Because of the lack of available stroke treatments, neuroprotective agents have also generated as much interest as thrombolytic therapies.

The immunosuppressive drug FK506 (also known as Tacrolimus or Prograf®) is often administered to patients receiving transplants to prevent organ rejection. Dervatives of the drug are also commonly used in the treatment of autoimmune diseases. FK506 inhibits T-cell activation by binding to members of the FK506-binding protein (FKBP) family. Interestingly, FK506, and several molecules with similar structures, also demonstrate neuroprotective and neuroregenerative effects in a wide range of animal models mimicking Parkinson's disease, dementia, stroke, and nerve damage.

Gunter Fischer and his colleagues at the Max-Planck Research Unit for Enzymology of Protein Folding in Germany have now determined that neuroprotective FK506 derivatives specifically target a receptor called FKBP38. "High FKBP38 activity in neuronal cells triggers mechanisms leading to programmed cell death," explains Fischer. "Inhibition of FKBP38 makes cells more predisposed to survive."

The scientists also synthesized a molecule that specifically inhibits FKBP38 and administered it to rats that were experiencing stroke symptoms. "We developed a lead compound that strongly inhibits FKBP38 leaving other brain FKBP almost untouched under certain conditions," said Fischer. "A strong neuroprotective effect became obvious in an animal model of stroke when the animals were treated with this lead compound."

Fischer and his colleagues found that their compound protected the rats' neurons and also caused neural stem cell proliferation and neuronal differentiation. Diseased animals with motor behavior deficits also showed improvement when they were given the synthetic drug.

These results suggest a potential therapeutic application specific FKBP38 inhibitors in the treatment of neurodegeneration following stroke and a number of other diseases.


###
The Journal of Biological Chemistry's Papers of the Week is an online feature which highlights the top one percent of papers received by the journal. Brief summaries of the papers and explanations of why they were selected for this honor can be accessed directly from the home page of the Journal of Biological Chemistry online at www.jbc.org.

The American Society for Biochemistry and Molecular Biology (ASBMB) is a nonprofit scientific and educational organization with over 11,000 members in the United States and internationally. Most members teach and conduct research at colleges and universities. Others conduct research in various government laboratories, nonprofit research institutions, and industry.

Founded in 1906, the Society is based in Bethesda, Maryland, on the campus of the Federation of American Societies for Experimental Biology. The Society's primary purpose is to advance the sciences of biochemistry and molecular biology through its publications, the Journal of Biological Chemistry, the Journal of Lipid Research, Molecular and Cellular Proteomics, and Biochemistry and Molecular Biology Education, and the holding of scientific meetings.

For more information about ASBMB, see the Society's website at www.asbmb.org.

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Questions to explore further this topic:

An anatomy of the brain

http://www.strokecenter.org/education/ais_anatomy/
http://braininfo.rprc.washingt.....atlas.html
http://www9.biostr.washington....../imageform

Blood vessels of the brain

http://www.strokecenter.org/education/ais_vessels/

A tutorial in neuroscience

http://thalamus.wustl.edu/course/

What is stroke?

http://www.strokeassociation.o.....er=3030066
http://www.stroke.org/site/Pag.....ame=STROKE
http://www.ninds.nih.gov/disor.....stroke.htm
http://www.mayoclinic.com/health/stroke/DS00150
http://www.clevelandclinic.org.....index=5601
http://www.ninds.nih.gov/disor.....stroke.htm
http://www.stroke.org.uk/infor.....index.html

Ten things one should know about stroke
http://www.stroke.org.uk/infor.....s_you.html

Brain attack
http://www.stroke.org.uk/infor.....ttack.html

Causes of stroke
http://www.stroke.org.uk/infor.....troke.html

Common symptoms
http://www.stroke.org.uk/infor.....ptoms.html

Transient ischaemic attack
http://www.stroke.org.uk/infor.....sient.html

Stroke can happen to anyone
http://www.stroke.org.uk/infor.....e_can.html

Damage to the brain
http://www.stroke.org.uk/infor.....o_the.html

Common problems after a stroke
http://www.stroke.org.uk/infor.....blems.html

Fact sheets on strokes
http://www.stroke.org.uk/infor.....index.html

Can children have strokes?

http://www.stroke.org/site/Pag.....=PEDSTROKE
http://www.pediatricstroke.org/stroke_facts.htm

What are the warning signs of a stroke?

http://www.strokeassociation.o.....mk_bck.pdf
http://www.strokecenter.org/pat/warning.htm

What are the common risk factors associated with strokes?

http://www.strokeassociation.o.....ifier=4716
http://www.strokefoundation.co.....6&id=1

Stroke risk scorecard

http://www.stroke.org/site/Doc.....?docID=601

How are some of these factors controlled?

http://www.strokeassociation.o.....er=3030165

How can stroke be prevented?

http://www.stroke.org/site/Pag.....me=PREVENT
http://www.stroke.org.uk/infor.....index.html

Why a stroke happens
http://www.stroke.org.uk/infor.....troke.html

Smoking
http://www.stroke.org.uk/infor.....oking.html

Alcohol
http://www.stroke.org.uk/infor.....cohol.html

Healthy eating
http://www.stroke.org.uk/infor.....ating.html

Exercise
http://www.stroke.org.uk/infor.....rcise.html

What are the types of stroke?

http://www.strokeassociation.o.....ifier=1014
http://www.strokecenter.org/pat/stroke_types.htm

Ischemic stroke
http://www.strokecenter.org/pat/ais.htm

Intracerebral hemorrhage
http://www.strokecenter.org/pat/ich.htm

Subarachnoid hemorrhage
http://www.strokecenter.org/pat/sah.htm

How is stroke diagnosed?

http://www.strokeassociation.o.....ifier=2552

How are cardiovascular and stroke related?

http://www.strokeassociation.o.....er=3027411

How is stroke treated?

http://www.strokeassociation.o.....ifier=2532

What are the effects of stroke?

http://www.strokeassociation.o.....ifier=1052
http://www.strokeassociation.o.....er=3036010

How does one deal with life after a stroke?

http://www.strokeassociation.o.....er=3030386

GAMES

http://www.brainsrule.com/kids/games/index.htm


Last edited by adedios on Sat Jan 27, 2007 4:44 pm; edited 2 times in total
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PostPosted: Tue Aug 22, 2006 8:17 am    Post subject: Mexican Americans have higher risk of stroke recurrence Reply with quote

John Wiley & Sons, Inc.
August 22, 2006

Mexican Americans have higher risk of stroke recurrence

Of the 700,000 people who have a stroke in the U.S. each year, roughly 200,000 have had one before. Recurrent strokes generally have worse outcomes and carry an increased risk of dying. Mexican Americans, the fastest growing segment of the U.S. population, have an increased risk of stroke compared to non-Hispanic whites, but the risk of recurrence and its effect on mortality has not been investigated until now. A study published in the September 2006 issue of Annals of Neurology (http://www.interscience.wiley.com/journal/ana), the official journal of the American Neurological Association examined stroke recurrence in Mexican Americans (MAs) and found that they had a higher risk compared with non-Hispanic whites (NHWs).

Led by Lynda D. Lisabeth, Ph.D., of the Department of Epidemiology at the University of Michigan, School of Public Health in Ann Arbor, MI, researchers identified stroke cases in Nueces County, TX as part of the BASIC project, a stroke surveillance project designed to study strokes in this isolated, urban community. From the beginning of 2000 until the end of 2004, researchers identified 1,345 patients who had their first stroke by analyzing hospital, nursing home and neurologists' records. A total of 53 percent of these patients were MA. They then identified those who had a recurrent stroke (126) and those who died of any cause following a first stroke (417).

"Recurrent stroke risk differed significantly by ethnicity," the authors state, "with MAs having higher recurrence risk." The differences seemed to be the largest for younger ages. In addition, stroke recurrence was significantly associated with risk of dying, but this was not affected by ethnicity.

Citing another study that showed that Hispanics of Puerto Rican heritage had almost a three-fold increased risk of recurrence compared with NHWs, the authors state "If future work confirms the current finding that Hispanics experience greater stroke recurrence risk compared with NHWs, factors contributing to ethnic differences should be investigated to improve outcomes following incident stroke." The current study also showed that those who had a recurrent stroke had a two to three-fold increased risk of death due to any cause. "The magnitude of this association was considerably larger than other predictors of death in this population including diabetes and coronary artery disease and indicates that in both ethnic groups, secondary stroke prevention is critical to improve survival following ischemic [inadequate blood flow] stroke," the authors state.

The authors note that the study did not examine whether there were differences in how traditional vascular risk factors, such as diabetes and hypertension, were handled in the two groups. "Differences in physician treatment, patient compliance, or differential drug effectiveness by ethnicity could also translate into increased stroke recurrence for MAs," they note. They add that it would be useful to investigate the rate of other vascular events following stroke and that this should be explored in future studies.

One interesting finding of the study was that MAs had better survival than NHWs following ischemic stroke, despite their increased risk of recurrence and the fact that recurrent stroke carried the same risk of dying in the two groups. The authors suggest that there may be unidentified factors that contribute to better survival in the MA population, such as better social support and/or genetic factors. Nonetheless, they suggest that efforts to reduce stroke recurrence in this population are needed.


###
Article: "Ethnic Differences in Stroke Recurrence," Lynda D. Lisabeth, Melinda A. Smith, Devin L. Brown, Lemuel A. Moyé, Jan M.H. Risser, Lewis B. Morgenstern, Annals of Neurology, September 2006, (DOI: 10.1002/ana.20943).
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PostPosted: Thu Aug 24, 2006 10:26 am    Post subject: Oxygen deprived brains repaired and saved Reply with quote

Research Australia

Oxygen deprived brains repaired and saved
23 August 2006

Scientists from Melbourne's Howard Florey Institute have found special proteins that protect the brain after it has been damaged by a lack of oxygen, which occurs in conditions such as stroke, perinatal asphyxia, near-drowning and traumatic brain injury.

Dr Nicole Jones and her team discovered that during oxygen deprivation, or 'hypoxia', these proteins (HIF1á and PHD2) increase.

These proteins regulate processes like the production of red blood cells and new blood vessels, and the flow of glucose to the brain. Therefore they are involved in preventing further brain damage and repairing damage caused by the initial injury.

This discovery takes the Howard Florey Institute's scientists closer to developing preventative and regenerative treatments for brain damage caused by hypoxia.

Dr Jones said her discovery resulted from looking at how the body tries to protect itself and how the brain reacts when it experiences mild, non-damaging hypoxia.

"I found that mild, non-damaging hypoxia actually protected the brain against a subsequent injury by activating certain proteins," Dr Jones said.

"Mild hypoxia appears to pre-condition neural tissues against a mass 'suicide' of healthy neurons after a stroke or other brain trauma.

"In an experiment in rats, mild hypoxia followed by a major stroke resulted in less brain damage than if the rat experienced just a major stroke – all because these protective proteins were increased by the first non-damaging exposure to hypoxia.

"I am now looking at developing both preventative and regenerative treatments that mimic these proteins' protective and repairing effects," she said.

Dr Jones is now testing drug candidates, and would like to develop new drugs that activate these protective proteins in the brain.

While further research is required, Dr Jones and her team are hopeful that their investigations will lead to effective treatments that will help people experiencing hypoxia, and also to improve recovery from hypoxic induced brain damage.


###
Dr Jones' research has been recently published in the Journal of Cerebral Blood Flow and Metabolism and Neuroscience Letters.

The Howard Florey Institute is Australia's leading brain research centre. Its scientists undertake clinical and applied research that can be developed into treatments to combat brain disorders, and new medical practices. Their discoveries will improve the lives of those directly, and indirectly, affected by brain and mind disorders in Australia, and around the world. The Florey's research areas cover a variety of brain and mind disorders including Parkinson's disease, stroke, motor neuron disease, addiction, epilepsy, multiple sclerosis, autism and dementia.

Dr Jones is available for interviews on Thursday 24 August from 9am - 12 midday and then again from 2:30pm to 5pm.
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PostPosted: Mon Dec 11, 2006 7:21 pm    Post subject: New research shows big improvement in survival after stroke Reply with quote

Research Australia
11 December 2006

New research shows big improvement in survival after stroke

A new research report by The George Institute for International Health, in collaboration with Auckland City Hospital and The University of Auckland, has revealed a 40% decline in the number of deaths after stroke in the total population of Auckland, New Zealand over the past 25 years. The study attributes the improved survival rate to health care factors associated with an increase in hospital admission and brain imaging during the most severe phase of the illness.

Stroke affects annually around 17 million people globally and is widely recognised as one of the biggest killers in both Australia and New Zealand. In New Zealand, over 7,600 strokes occur each year, while over 53,000 strokes take place in Australia per annum. However, research into stroke rates has shown a steady decline in stroke in many industrialised countries over recent decades, most notably in Caucasian populations, whilst Maori and Pacific populations in New Zealand have experienced a rise in stroke rates. Even with declines in the rate of stroke, the number of strokes occurring is expected to rise, with the ageing of the population and improved survival.

In three separate studies between 1981 and 2003, researchers investigated the rate of short and medium-term survival after stroke and found that the probability of survival increased from 1981, especially in the 28-day period following a stroke. According to Principal Investigator, Professor Craig Anderson, Director of the Neurological and Mental Health Division at The George Institute, the rate of hospitalisation, brain imaging (CT or MRI scans) and medical attention have all increased dramatically over the period. "In 1981, 64% of patients were admitted to hospital and 13% would have brain imaging. In 2003, 92% of patients were being admitted to hospital with 90% receiving scans. This improved level of stroke care has directly benefited stroke sufferers across New Zealand."

However, as the death rate declines, there has been a significant increase in the number of patients with an impaired level of consciousness and motor deficits following stroke. Dr Kristie Carter, Research Fellow for the study noted that, "We found that a person’s level of consciousness at the time of stroke, age and history of pre-morbid dependency, were strong predictors of survival".

"The increased number of stroke survivors in New Zealand is a positive outcome, showing more knowledge of the condition and how to treat it," says Associate Professor Valery Feigin of The University of Auckland’s Clinical Trials Research Unit. "However, this also puts an additional burden on resources, both family and community. More needs to be done in preventing strokes and implementing evidence-based management and rehabilitation strategies (for example, Acute Stroke Units). In addition, there needs to be increased awareness of the condition and how to reduce risk factors that can lead to strokes, such as elevated blood pressure, smoking, poor diet etc. Only through this can we reduce the incidence of stroke and ultimately improve stroke outcome."

###
This study was funded by the Health Research Council (HRC) of New Zealand and published in the Cerebrovascular Diseases journal.

Notes to Editor:

The George Institute for International Health is an internationally-recognised health research body, undertaking high impact research across a broad health landscape. The Institute is centrally involved with Australian community health issues in Aboriginal health, ethnic community health, road safety and injury, mental health, ageing, healthcare access, clinical practice in Australian hospitals and health policy development.

It is also a leader in the clinical trials, health policy and capacity-building areas. Its research has a direct, practical impact on a wide range of healthcare, health policy, safety and socio-cultural issues facing Australians.

The Institute is affiliated with The University of Sydney, Sydney South West Area Health Services, and collaborates in its research with other prestige research institutes, clinical authorities and policy centres around the world.
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PostPosted: Tue Apr 24, 2007 10:01 am    Post subject: New University of Leicester study could help stroke victims Reply with quote

University of Leicester
24 April 2007

New University of Leicester study could help stroke victims

A University of Leicester study could help to provide a new lease of life for patients who have suffered a stroke.

The research published in the American Journal of Hypertension confirms the safety of a drug, Lisinopril, that lowers their blood pressure-without reducing the blood flow to the brain.

Now a larger Leicester trial is under way to investigate the drug’s benefits for victims of strokes.

Dr David Eveson, of the Department of Cardiovascular Sciences at the University of Leicester, said: "High blood pressure is common immediately after a stroke. Stroke patients with high blood pressure tend to have a worse outcome than those with normal blood pressure and therefore it may be helpful to lower blood pressure immediately after stroke.

"However, trials to date have shown variable results, probably because treatment was either started too late or the wrong drug was used.

"The ACE inhibitor class of blood pressure lowering drugs, of which Lisinopril is a member, have been shown in studies to lower blood pressure but preserve the blood flow to the brain which may be all important after stroke. This study compared the use of blood pressure lowering with Lisinopril versus placebo treatment within a few hours of acute stroke in patients presenting to University Hospitals Leicester. The results showed that blood pressure was effectively lowered in the treated group and this did not result in any adverse outcome in comparison with placebo.

"The study was too small to demonstrate any benefit but it did confirm safety and thus a larger Leicester-based trial (CHHIPS) is under way to see if this treatment can be of benefit to patients."

Dr Eveson added: "Stroke is the second commonest cause of death in the UK and the commonest cause of adult disability. It is imperative that we strive to discover new treatments for stroke to reduce the substantial impact of this disease.

"This study evaluates, for the first time, an established blood pressure lowering drug immediately after stroke and confirms its safety in this group, thereby paving the way for larger studies to discover if it may benefit patients."

###
The study is entirely led by the University of Leicester which is in the forefront of international stroke research.
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PostPosted: Thu May 17, 2007 12:46 pm    Post subject: Lowering Body Temperature Could Aid Standard Stroke Treatmen Reply with quote

Lowering Body Temperature Could Aid Standard Stroke Treatment
17 May 2007
University of Cincinnati


CINCINNATI—University of Cincinnati (UC) scientists have developed a model that could help physicians combine current clot-busting medication with below-normal body temperatures (hypothermia) to improve the treatment of ischemic stroke patients.

Thought to be first report of the temperature dependence of the standard, FDA-approved stroke medication—an enzyme called tissue plasminogen activator (tPA)—in human clots and plasma, the findings could prove useful in predicting the efficacy of tPA over a wide range of temperatures, the UC researchers say.

The work is reported in the May 2007 issue of Physics in Medicine and Biology.

It is already known that lowering a patient’s temperature reduces the metabolic activity of ischemic (clot-causing) cells, which in turn reduces cell damage and death.

But, says George Shaw, MD, PhD, who led the UC team, while several research centers are studying the use of hypothermia treatment for both stroke and heart attacks, little is known about how effective tPA is in the lab or the human body at lower temperatures.

Using the Celsius (centigrade) scale, normal human body temperature is 37 degrees. Shaw and his team tested tPA, which like most enzymes is very temperature dependent, to see how well it broke up clots at temperatures ranging from 30 to 39.5 degrees Celsius.

The researchers used blood samples from ten healthy donors to form 226 small clots, exposed the clots to fresh-frozen human plasma and tPA at various temperatures, then measured how much mass the clots lost.

Shaw says that while he and his colleagues fully expected to find that tPA is less effective at lower temperatures, their study enabled them to develop a model to explain the mechanism of how tPA gets into the clot and subsequently breaks it up.

“Around 33 Celsius is what most folks would consider the target temperature in cooling for therapeutic hypothermia,” Shaw explains, “although there have been suggestions that 35 Celsius would be useful as well.”

The UC researchers found, however, that at 33 degrees Celsius, clots exposed to tPA lose only 8.8 percent of their mass, compared with 12 percent at 37 degrees Celsius.

“So, very crudely,” Shaw says, “if you’re administering therapeutic hypothermia and tPA at the same time, you might want a higher tPA dosing, since it is less effective at lower temperatures.”

Another consideration, however, Shaw explains, is the role of the body enzyme plasminogen, which tPA converts into plasmin, a so-called proteolytic enzyme that actually does the work of dissolving the clots.

“Without sufficient plasminogen,” Shaw says, “more tPA won't help, so I suspect if one wants to use hypothermia and tPA at the same time, something else might be needed to help the tPA work better.”

Shaw says the model of the tPA-hypothermia interaction that his team has developed from the study may be useful in helping researchers predict the efficacy of tPA over a wide range of temperatures.

“Knowing the effectiveness of tPA at various temperatures could allow a physician to adjust tPA dosing in a stroke patient if hypothermia is being induced as well,” says Shaw.

“There are multiple medications and treatments for heart attacks, but not for stroke,” he adds, “because stroke therapies are still in their infancy. This study offers another potential option for treatment.”

Also collaborating on the study, which was funded by the Whitaker Foundation and the National Institute of Neurological Disorders and Stroke, were UC researchers Ashima Dhamija, Nazli Bavani, Kenneth Wagner, MD, and Christy Holland, PhD.
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PostPosted: Wed May 30, 2007 11:15 am    Post subject: Limiting stroke damage is focus of study Reply with quote

Medical College of Georgia
30 May 2007

Limiting stroke damage is focus of study


Brain damage that occurs even days after a stroke, increasing stroke size and devastation, is the focus of researchers trying to identify new treatments.

"This would be a death wave coming through; neurons are dying here," says Medical College of Georgia Neuroscientist Sergei Kirov as he watches moving images of compounding events that kill brain tissue in the stroke's core.

Within seconds of a clot or hemorrhage cutting off blood, oxygen and glucose, the neuron's powerhouses, or mitochondria, shut down and the key energy source ATP goes away. Energy loss shuts down the sodium-potassium pump and the membrane that keeps the right substances inside and outside the cell becomes dysfunctional. Neurons swell and the proper electrical balance – essential for neuronal activity – is lost.


"This is what is happening in the ischemic core; dendrites get beaded, spines are lost and synapses are probably lost at the same time," says Dr. Kirov describing rapidly deteriorating communication points for neurons. "This is not recoverable; everything dies here," he says of the destruction, termed anoxic depolarization.

Damage doesn't stop there. In the minutes, hours and even days following stroke, waves of peri-infarct depolarization pound surrounding brain tissue, where blood flow is reduced by about 60 percent.

"It's enough oxygen and energy for neurons to survive for some time, but not enough to function properly," says Dr. Kirov, who received a $1.4 million, five-year grant from the National Institute of Neurological Disorders and Stroke, to study this compromised tissue around the stroke core called the penumbra. His grant was ranked among the top 1 percent of those reviewed by the study section.


"If the recurring waves continue, finally they will kill cells," says Dr. Kirov who wants to better understand this depolarizing event with the goal of stopping it. "We are trying to block this event to save the penumbra. Part of the recovery is if you can restore the normal electrical activity of neurons. We need some energy to do that."

He's using real-time microscopical imaging to monitor changes in neurons and their dendrites and spines following a stroke, and pharmaceuticals – including an antibiotic and an anesthetic – to try to stop it. Disintegration of a neuron's dendrites and spines, which receive messages from other neurons via synapses, is an early indicator of trouble. Studies are being done in an animal model for stroke and dissected but still-viable brain tissue.

"The penumbra exists for several days, so this is basically a window of opportunity to save this region, but we don't yet have good drugs to do this. We need to target this area for drug treatment," Dr. Kirov says.

So Dr. Kirov studies dendrite and spine damage that occurs in anoxic depolarization and peri-infarct depolarization and watches their recovery after a short simulated stroke.

He believes by finding a way to inhibit anoxic depolarization in a slice of living brain, he can protect neurons by stopping structural and functional damage and promoting recovery.

His previous work has shown that cold also inhibits the sodium-potassium pump, resulting in dendrite beading and spine loss, and that warming of brain tissue and pump revival quickly heals old spines and induces new ones.

Now he wants to know if the new spines function and last and if this adaptive recovery also occurs when stroke is the culprit.
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PostPosted: Mon Jun 04, 2007 11:21 am    Post subject: Explaining a link between strokes and Alzheimer's Reply with quote

University of Leeds
4 June 2007

Explaining a link between strokes and Alzheimer's

University of Leeds scientists have shown how stroke victims could be more vulnerable to Alzheimer’s disease – years or even decades after making a full recovery.

It has been known for some time that the two conditions were linked, but now the Leeds team has shown how an incident of reduced oxygen to the brain – caused by the stroke – can leave the patient vulnerable to the gradual build-up of toxic chemicals which can cause Alzheimer’s.

The research was led by Professor Chris Peers of the University’s school of medicine, who explained: “Our research is looking into what happens when oxygen levels in the brain are reduced by a number of factors, from long-term conditions like emphysema and angina, to sudden incidents such as a heart attack, stroke or even head trauma. Even though the patient may outwardly recover, the hidden cell damage may be irreversible.

“It could even be an issue for people who snore heavily, whose sleep patterns are such that there will be times in the night when their brain is hypoxic – deprived of sufficient oxygen. It can be anything that stops the heart and lungs working together to their optimal capabilities.”

The research centred on the damage done by these low-oxygen incidents to a group of brain cells called astrocytes. When the brain is functioning normally, it makes connections through the release of tiny amounts of chemical across the synapses. Once the chemical has been transmitted, it is “mopped up” by the astrocytes.

The Leeds team – which also includes Dr John Boyle in the Faculty of Medicine and Health and Dr Hugh Pearson of the Faculty of Biological Sciences – has shown that if at some point the astrocytes have become hypoxic, they are less able to mop up these transmitters, allowing the residual chemicals to accumulate and become toxic.

“This is an important factor in what’s going on in hypoxic brains,” said Prof Peers, whose work received funding from the Alzheimer’s Society and the Alzheimer’s Research Trust. “Astrocytes are just as essential as neurones for normal brain function – and we have ten times as many of them.”

Professor Susanne Sorensen, head of research at the Alzheimer's Society, added: "The team examined the role of cells that support neurones in the brain. This is exciting because rather than focussing on neurones they looked at processes in the brain, which until now have not be researched in so much detail."

In another project, the team is investigating two key signalling molecules which are very sensitive to fluctuations in oxygen levels. The scientists suspect that in low oxygen conditions these molecules could begin the increased production of a toxic protein called amyloid which builds up in the brains of people with Alzheimer’s.

The work at Leeds is part of a network of research projects nationally and internationally, which are adding to the sum of knowledge about a disease which costs the UK more than cancer, heart disease and stroke combined.

There are around 700,000 people in the UK currently suffering with dementia – a figure that is set to more than double by 2050, simply because we are living longer. And the disparity between funding levels for research into different conditions is stark, as Prof Peers explained: “For every cancer patient in this country, between £300 and £400 is spent every year on research. For Alzheimer’s sufferers it is closer to £15, yet sufferers can need full-time care for the last 20 to 30 years of their lives, so any research into intervention can be really cost-effective in the long term.”

###
Further information

Around 700,000 people in the UK – including 20 per cent of those aged over 80 – have a form of dementia. Alzheimer’s disease accounts for more than half of these. Alzheimer’s is not a normal, unavoidable part of getting older, but a fatal and incurable brain disease. It can take 30 years to develop. Beyond the age of 65, your chance of developing Alzheimer’s doubles every five years.

The Alzheimer's Research Trust is a UK dementia research charity dedicated to finding ways to treat, cure or prevent Alzheimer's disease, vascular dementia, Lewy Body disease and fronto-temporal dementias. With no government funding it relies on public donations to fund its vital research. The Trust provides free information to the public on dementia and the treatments currently available. Call 01223 843899 or visit www.alzheimers-research.org.uk

The Alzheimer's Society works across the UK to champion the rights of people living with dementia and those who care for them. As a charity, the society depends on the generosity of the public to help it care, research and campaign for people with dementia. You can donate now by calling 0845 306 0898 or visiting www.alzheimers.org.uk. The Alzheimer's Society Dementia Helpline number is 0845 300 0336 or visit www.alzheimers.org.uk
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PostPosted: Fri Jul 06, 2007 9:29 am    Post subject: One-Fifth of Hospitals Give Bad Emergency Advice on Stroke Reply with quote

One-Fifth of Hospitals Give Bad Emergency Advice on Stroke
By Ed Edelson, HealthDay Reporter

posted: 05 July 2007 04:12 pm ET

(HealthDay News) -- Americans who think they're having a stroke face better than a one-in-five chance of getting the wrong -- and potentially fatal -- advice when they call local hospital personnel, a new study shows.

Although experts say the best thing to do when suspected stroke symptoms appear is to immediately call emergency 911, in 22 percent of cases, hospital personnel who answered the phone advised that patients call their family doctor.

"That might seem reasonable, but it often delays proper care," said lead researcher Dr. Brett Jarrell, an emergency department staff physician at the Cabell Huntington Hospital in Huntington, W.Va. "Sometimes they can't get through to the doctor, or there can be other delays," he noted.

An interlocking set of problems delay that emergency treatment too often, he said. Not only do many hospital workers not know what to do when a stroke might be occurring, but many Americans still don't recognize key symptoms that signal a stroke, Jarrell said.

For the full article:

http://www.livescience.com/healthday/606149.html
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PostPosted: Thu Sep 06, 2007 11:27 am    Post subject: Adult Brain Can Still Change Reply with quote

Adult Brain Can Still Change

By Jeanna Bryner, LiveScience Staff Writer

posted: 06 September 2007 10:56 am ET

A new case study of a stroke patient suggests that adults' brains might be just as "plastic," or capable of creating new neural pathways, as those of children.

Past research has established the remarkable capacity of young brains to change or adapt to deficits by creating new signaling routes, a phenomenon called plasticity. However, whether adult brains have that same capacity has remained controversial.

Results from a new study, published in the Sept. 5 online edition of the Journal of Neuroscience, suggest at least in one patient, the visual center of an adult brain can reorganize itself neurally to overcome damaged pathways and result in changes (and possibly improvements) in visual perception.

For the full article:

http://www.livescience.com/hea.....hange.html
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PostPosted: Sat Sep 22, 2007 9:51 am    Post subject: Link Between Air Pollution, Stroke Gets Clearer Reply with quote

Link Between Air Pollution, Stroke Gets Clearer
By Robert Preidt, HealthDay Reporter

posted: 21 September 2007 09:34 am ET

(HealthDay News) -- Microscopic pollution particles spewed by diesel engines and coal-burning plants may spur blood clots that can trigger heart attacks and strokes, U.S. scientists say.

Researchers at Northwestern University in Chicago found that these tiny particles -- which are less than one-tenth the diameter of a human hair and too small to be filtered by the nose or mouth -- caused hyperclotting of the blood in animals.

For the full article:

http://www.livescience.com/healthday/608177.html
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PostPosted: Mon Nov 26, 2007 1:45 pm    Post subject: Hundreds of strokes avoidable, says study Reply with quote

University of Manchester
23 November 2007

Hundreds of strokes avoidable, says study

Hundreds of strokes could be prevented each year if patients suffering ‘mini strokes’, known as transient ischaemic attacks or TIAs, were assessed sooner by specialist clinicians.

A University of Manchester study has found that almost two-thirds of patients attending what are termed ‘rapid access’ TIA clinics took more than the recommended seven days to be seen by a suitably trained professional.

A TIA, often characterised by a temporary weakening of one side of the face and the corresponding arm, drastically increases a person’s chance of suffering a major stroke within days of the initial symptoms, with some studies putting the risk as high as a one-in-four probability.

Despite the obvious importance of early assessment, the research – published today (Thursday) ahead of print in the Journal of Neurology Neurosurgery and Psychiatry – suggests that, on average, access to the specialist clinics takes at least twice as long as it should.

“Current UK guidelines recommend that all people who have had a TIA should be assessed by a specialist within seven days of the start of symptoms,” said Dr Craig Smith, from the University’s clinical neuroscience group which coordinated the research.

“Our findings suggest that this standard is not being met and, in reality, TIA patients should ideally be assessed for risk of further stroke within a couple of days, if not on the same day as the initial symptoms.”

Dr Smith and the research team studied 711 people who had sustained a TIA or minor stroke, on average, 15 days earlier and who were seen at five centres in Liverpool and Manchester in the North West of England.

A scoring system (ABCD2), which has been used to assess stroke risk very early after TIA, was also able to detect risk of stroke despite the delays in presentation to specialist assessment.

Every patient was monitored for three months to check their risk of recurrent TIA, stroke, heart attack, or death. Of the 711 patients monitored, 25 went on to have a major stroke while 100 had at least one further TIA during the follow-up period. Three people died.

“This rate of stroke was relatively low due to the delay in being able to assess the patients after their initial TIA,” said Dr Smith. “Some studies have put the number of people suffering a major stroke within a week of a TIA as high as 10%, which suggests even the seven-day guideline figure may be inadequate.”

The delay in TIA patients being assessed by a stroke specialist is due to a number of reasons, including the patients themselves not realising the potential serious nature of the attack. Initial symptoms are temporary, lasting a matter of minutes or hours before the face, arm and, sometimes, leg return to normal, so patients often feel well by the time they are seen by a clinician.

Dr Smith added: ”Our findings suggest that current provision of TIA services, where delayed presentation to ‘rapid access’ TIA clinics is common, does not appear to provide an appropriate setting for urgent evaluation or timely secondary prevention in those who may be at the highest risk of stroke.

“If the speed with which TIA patients can be evaluated is improved many strokes in the UK each year could be prevented.”
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PostPosted: Thu Dec 27, 2007 9:51 am    Post subject: High triglycerides, other cholesterol raise risk of stroke Reply with quote

American Academy of Neurology
26 December 2007

High triglycerides, other cholesterol raise risk of stroke
ST. PAUL, Minn. – People with high triglycerides and another type of cholesterol tested but not usually evaluated as part of a person’s risk assessment have an increased risk of a certain type of stroke, according to research published in the December 26, 2007, online issue of Neurology®, the medical journal of the American Academy of Neurology.

“LDL or ‘bad’ cholesterol has been the primary target for reducing the risk of stroke, but these results show that other types of cholesterol may be more strongly linked with stroke risk,” said study author Bruce Ovbiagele, MD, of UCLA Medical Center in Los Angeles, CA, and member of the American Academy of Neurology.

The researchers analyzed the records of 1,049 people admitted to a university hospital with a stroke or mini-stroke over four years. Of those, 247 people had a large artery atherosclerotic stroke. This is a type of ischemic stroke caused by a blockage of blood flow to the brain. People with this type of stroke have blockage in the large arteries leading to the brain.

Those with high triglycerides and elevated “non-high density lipoprotein cholesterol” were more likely to have a large artery atherosclerotic stroke than those with low levels of these fats in the blood.

Those with the highest triglycerides were 2.7 times more likely to have this type of stroke than those with the lowest level. Triglycerides are fatty acids and are the most common type of fat in the blood. Those with the greatest non-high density lipoprotein cholesterol, which is neither the “good” nor the “bad” cholesterol, were 2.4 times more likely to have a large artery stroke.

“Because this type of cholesterol is included in the test that is normally ordered, and triglycerides are already reported, it would not be difficult to start paying closer attention to these factors in people at risk for large artery stroke,” Ovbiagele said.

The study found that people with high “bad” cholesterol did not have an increased risk of this type of stroke. Ovbiagele noted that it is still important to monitor bad cholesterol levels to reduce risk of heart disease and other types of stroke.


###
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 disease, and multiple sclerosis.

For more information about the American Academy of Neurology, visit www.aan.com
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