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Cholesterol-lowering drugs and the risk of hemorrhagic stroke

Contact: Angela Babb
ababb@aan.com
651-695-2789
American Academy of Neurology

ST. PAUL, Minn. – People taking cholesterol-lowering drugs such as atorvastatin after a stroke may be at an increased risk of hemorrhagic stroke, or bleeding in the brain, a risk not found in patients taking statins who have never had a stroke. But researchers caution the risk must be balanced against the much larger overall benefit of the statin in reducing the total risk of a second stroke and other cardiovascular events when making treatment decisions. The research is published in the December 12, 2007, online issue of Neurology®, the medical journal of the American Academy of Neurology.

For the study, researchers conducted a secondary analysis of the results of the Stroke Prevention with Aggressive Reduction in Cholesterol Levels (SPARCL) clinical trial. The trial enrolled 4,731 people who were within one to six months of having had a stroke or transient ischemic attack, or mini-stroke, and with no history of heart disease. Half of the participants received atorvastatin and half received a placebo. The participants were then followed for an average of four and a half years.

Overall, treatment was associated with a 16-percent reduction in total stroke, the study’s primary endpoint, as well as significant reductions in coronary heart events. However, secondary analysis found that the overall reduction in stroke included an increase in the risk of brain hemorrhage. Of those people randomized to atorvastatin, the study found 2.3 percent experienced a hemorrhagic stroke during the study compared to 1.4 percent of those taking placebo. The study also found there was a 21-percent reduction in ischemic stroke, a more common type of stroke involving a block in the blood supply to the brain, among people taking atorvastatin.

Other factors were also found to increase the risk of brain hemorrhage. For example, those who had experienced a hemorrhagic stroke prior to the study were more than five times as likely to suffer a second stroke of this kind. Men were also nearly twice as likely as women to suffer a hemorrhagic stroke. People with severe high blood pressure at their last doctor’s visit prior to the hemorrhagic stroke had over six times the risk of those with normal blood pressure.

“Although treatment of patients with a stroke or transient ischemic attack was clearly associated with an overall reduction in a second stroke, hemorrhagic stroke was more frequent in people treated with atorvastatin, in those with a prior hemorrhagic stroke, in men and in those with uncontrolled hypertension,” according to study author Larry B. Goldstein, MD, with Duke University Medical Center in Durham, North Carolina, and Fellow of the American Academy of Neurology. “This risk of hemorrhagic stroke also increased with age.”

“Treatment with atorvastatin did not disproportionately increase the frequency of brain hemorrhage associated with these other factors. The risk of hemorrhage in patients who have had a transient ischemic attack or stroke must be balanced against the benefits of cholesterol-lowering drugs in reducing the overall risk of a second stroke, as well as other cardiovascular events,” said Goldstein.

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The SPARCL trial was funded by Pfizer, the maker of atorvastatin.

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 http://www.aan.com.

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December 13, 2007 Posted by | American Academy of Neurology, Baltimore, Barcelona, Bethesda, Boston, Calgary, Canada, FMS Global News, France, Germany, Global, Global Health Vision, Global News, Hemorrhagic Stroke, Italy, London, London UK Feed, Medical Journals, Newfoundland, News, News Australia, News Canada, News France, News Germany, News Israel, News Italy, News Jerusalem, News Switzerland, News UK, News US, News USA, Nova Scotia, Ottawa, Ottawa City Feed, Quebec, Research, RSS Feed, Slovakia, Spain, Statin Drugs, Stroke, Toronto, Toronto City Feed, UK, US, Virginia, Washington DC, Washington DC City Feed, World News | , , | Leave a comment

FOOD FOR SKINNY KIDS – A STORY WHICH NEEDS TO CIRCULATE FOREVER

by Jeanne Hambleton © 2007
NFA Leader Against Pain – Advocate

Maybe I should mention that you just might need some kleenex tissues before you start this story but please read it anyway, if only in the spirit of Goodwill to All Children. The men are big enough to look after themselves.

As folks in the UK were getting ready this morning to do some Christmas shopping an email arrived on my desktop with a warning, which said,  “This email needs to circulate forever.”

How could I pass up this invitation to inquire within? The email also stated, “This is a real eye opener. A real tear jerker No prerequisites (commitments).  Simply, because everyone should be reminded.“

This was sent to me by a lady from Montevideo, Uruguay called Marta. Where the pictures, shown in the email, were taken, it does not say, but I am sure it conveys a worldwide message, especially within the African continent.

Picture 1. shows European students sat at computers working, with the caption, “Does studying annoy you?”
Picture 2. reveals children, possibly from Africa, without shoes, sat on a bench and drawing their lessons in the dirt with their fingers. The caption says, “ Not them!”


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Picture 3. is a happy family picture of a father with his daughter enjoying a beef burger roll with the words, “Hate veggies?”
Picture 4. is a picture of a long line of native mothers and starved children, clothed, in rags and waiting in line with a bowl for some food handouts. This caption says, “They starve from hunger!”


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Picture 5. reveals the back view of a jolly obese child having fun, with a caption which reads, “On a diet?”
Picture 6. gives a close-up of a painfully thin starved child with a tape measure around the child’s matchstick thin arm. The caption referring to diet says, “They die from it!” Or the lack of any kind of diet.


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Picture 7. shows a baby being cuddled by a parent revealing the lovely cuddly cheeks of a child’s bottom. This reads, “Does your parent’s care tire you?”
Picture 8. shows a sibling cuddling a child with the last bone in the baby’s spine clearly visible as she rests in sister’s arms for comfort. This caption tells us these children have no parents to grow tired of. “They don’t have any!”


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Picture 9. reveals youngsters sat at a games console and states, “Bored with the same game?”
Picture 10. Shows a young unclothed child playing in the dirt with a bit of stick, next to the human skull of someone who had probably died from starvation. The caption reads, “They have no option!”


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Picture 11. shows a smart new trainer with a caption which reads, “Someone got you Adidas instead of Nike?”
Picture 12. pictures the feet of a child with half of a plastic bottle cut to make the sole of a pair of sandals. The picture clearly reveals the screw top of the plastic bottle on the footwear, which is tied onto the foot with rag. This caption states, “They only have one brand?” Maybe it is cola?????


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Picture 13. is of a sweet little girl in clean pyjamas snuggled up in her cosy bed. This caption reads, “Aren’t you thankful for a bed to sleep in?”
Picture 14. The final contrast picture shows a child laying in the dirt, half covered with a piece of old rag, trying to sleep, with a caption that reads, “They’d wish not to wake up!”


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The closing slide asks, “Are you still complaining? Observe around you and be thankful for all that you have in this transitory lifetime…. We are fortunate to have much more than what we need to be content. Let us try not to feed this endless cycle of consumerism and immortality in which this ‘modern and advanced’ society forgets and ignores the other two thirds of our brothers and sisters. Send this information without any obligation or expectation in receiving good luck. Don’t keep it! Send it and it won’t be in vain. Let us complain less and give more!”

I imagine you feel as I do. I work hard for my dollar and I do not believe in sharing my hard earned cash with large charities who have magnificent offices, managing directors, hundreds of paid staff and devote just a fraction of their donations to their ‘good’ works. You can call me the woman with the long pockets if you like, but I want to know my money is going where it will doing some good and helping those would really need it. How to be confident about that I am not sure? In true Scorpion fashion I hate to be misled or deceived.

Quite how we can help these starving children is the burning question. I have had masses of appeals for all sorts of charities drop on my doormat in recent weeks. At least these ends up in the local hospice waste paper recycling skip and help them a little along with our papers and magazines. I looked on the Internet at our UK BBC Children in Need but could not see children in a similar situation.

SAVE THE CHILDREN
The UK Save the Children organisation has produced a Christmas shopping catalogue, on line, so should you decide to buy Christmas gifts from them you are indirectly donating while shopping, just how much remains to be seen! Perhaps this might be more acceptable – buying and giving at the same time. It is easy to look at this site to see the work they are doing and possibly shop with them. Every Christmas I seem to receive more and more cards printed by charities and sent by to me by friends.

http://www.savethechildrenshop.co.uk/home

However I should mention that if you telephone their UK number – 0844 557 5425 – instead of ordering on line, it could cost you 40p a minute as you give your details and make your mind up. Some of that money will be going to the charity.

Our doctors’ surgery is using this 0844 prefix number and getting a rake off which is a bit vexing considering how much our GPs are reported to be earning – but that is another story.

No – I am not a sales rep for any charity – just a concerned parent. No, this is not a commercial for children’s charities – it is a wake up call.

The American Save the Children website also appears to have a programme for under privileged children in developing countries, who are suffering from hunger and poverty. It seems you can also purchase festive gifts from them indirectly helping the cause.

http://www.savethechildren.org/

What you decide to do is between you and your conscience. I would however like to leave you with these thoughts.

These pictures and words certainly do bring you down to earth especially when you consider the wastage by governments the world over.  I am just sorry I could not reproduce the pictures but I am sure you know the kind of scenes I mean – you must have seen them on TV from time to time. Send me your email address with the request for these pictures if you would like them forwarding.

Just consider the money all of the worldwide governments squander… it is time someone added the total figure and gave us some home truths.

These starving children, if they live, may be our next generation – our future leaders. Do you think if they survive they could be future terrorists? I am sure they will have a grudge against the world – surely they will feel the world owes them a living. This is all very sad and really makes you think. Whatever happened to the innocence of childhood?  

Just imagine what we spend on consumerism not to mention what we will spend on our own children this Christmas 2007. I wonder what our children would think if we put these pictures under the Christmas tree on Dec.25 instead of a new bike, a new game toy and all the other things children of our modern world expect to receive from their parents aka Father Christmas?

What would it be like if children all over the world went without just one toy from their festive gifts in aid of the starving and poverty stricken children. It would take a lot of organizing to gather in that money and it is a huge task but it could be done – all it needs is a good website supported by reliable well known people…. even if it took until Easter to collect the money – the children would still be starving.

Where are you Bob Geldorf? Can you help us with this? Does someone know his email address? My mind is boggling at the power of the people…… How about Skinny Kids for a campaign title – that rather sums it up!

Just a thought – maybe if that £5 we would be spending on a nonsense stocking gift for someone who has everything, was replaced with a warm note telling them Christmas is for children – starving children in particular – and they would be receiving his gift money with a tax gift aid. Sorry but this has been sent to starving “Skinny Kids” who have nothing.

I would hope we would get a really warm hug for this initiative. This friend really did not need an air freshener toy for his car or a key ring. If we did not get a big hug that receiver is a Christmas Meanie…. Take it from me. We will cross him off our Christmas list in future – so there.

Sorry to be a party pooper – but someone has to do it.  I will make up for it and send you some happier stories in the near future.

Take care. Jeanne.

November 26, 2007 Posted by | Childhood Nutrition, Global Health Vision, Global News, Health, Hunger, London UK Feed, News, News Australia, News Canada, News France, News Germany, News Israel, News Italy, News Switzerland, News UK, News US, News USA, Ottawa, Ottawa City Feed, RSS Feed, Toronto, Toronto City Feed, UK, Virginia, Washington DC, Washington DC City Feed, World News | , , | Leave a comment

Antibody leads to repair of myelin sheath in lab study of multiple sclerosis and related disorders

Contact: Amelyn Reyes
newsbureau@mayo.edu
507-284-5005
Mayo Clinic

ROCHESTER, Minn. — Mayo Clinic researchers have found that a human antibody administered in a single low dose in laboratory mouse models can repair myelin, the insulating covering of nerves that when damaged can lead to multiple sclerosis and other disorders of the central nervous system.

The study will be presented on Oct. 9 at the American Neurological Association meeting in Washington, D.C.

“The repair of chronic spinal cord injury is seldom modeled in laboratory studies, but it is an important reality for the treatment of humans. The concept of using natural human antibodies to treat disease of this kind has not yet been tested in humans, but these research findings are very promising,” says Moses Rodriguez, M.D., a Mayo Clinic neurologist and the study’s corresponding author. “The findings could eventually lead to new treatments that could limit permanent disability,” states Arthur Warrington, Ph.D., a Mayo Clinic scientist and study author.

Myelin repair normally occurs spontaneously, but in multiple sclerosis and other disorders of the central nervous system, the myelin repair process occurs very slowly or fails altogether. Researchers are trying to determine how to speed up the myelin healing process, which they hope will eventually lead to new treatments for patients.

The antibody, which was genetically engineered from a single cell, binds to myelin and the surface of cells in the brain and spinal cord, then it triggers the cells to begin the repair process called remyelination. This antibody is the first known reagent designed to induce repair by acting within the central nervous system at the damage sites on cells responsible for myelin synthesis.

The study uses laboratory mouse models of chronic progressive multiple sclerosis in humans. The severity of the disease and also success of the treatment were largely defined by how naturally active the mice were, particularly during the night because mice are nocturnal and are especially active at this time. They received a single dose of the antibody. A minimum of 25 mcg/kg was needed to trigger remyelination, which is equivalent to about 2 mg in the average adult, considered a very low dose. The myelin repair plateaued after five weeks in the mice models.

In addition, when combined with daily methylprednisolone, (an immune modulating steroid) the antibody still promotes remyelination in mouse models. This is an important fact because the first multiple sclerosis patients treated with the antibody will have been treated first with methylprednisolone.

As a naturally occurring protein of the immune system, antibodies do not appear to carry any side effects, nor are they toxic — even when administered at 4,000 times the minimal effective dose — though the concept has not yet been tested in humans, the researchers say.

In summary, this antibody:

Promotes remyelination with a single dose as low as 25 mcg/kg in mice models

The remyelination plateaus at five weeks after a single dose

Converts a model of chronic immune mediated demyelination to one that repairs with the speed of a toxin induced model of demyelination

In terms of replicating the findings in humans, the researchers have already produced the antibody through genetic engineering and conducted preliminary toxicology experiments in mice showing that 1,000 times the therapeutic dose is not toxic. The study continues to be explored in animal models and eventually, in clinical trials.

In short, the critical finding is that when combined with methylprednisolone, the antibody still effectively promotes remyelination and does not make the mice worse, Dr. Warrington states.

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About Multiple Sclerosis:

Multiple sclerosis (MS) is a chronic, potentially debilitating disease that affects the central nervous system, which is made up of the brain and spinal cord. Multiple sclerosis is widely believed to be an autoimmune disease, a condition in which the immune system attacks components of the body as if they’re foreign.

Multiple sclerosis affects an estimated 300,000 people in the United States and probably more than 1 million people around the world — including twice as many women as men. Most people experience their first signs or symptoms between ages 20 and 40.

Collaboration and Support

The study was funded by the National Institutes of Health, the National Multiple Sclerosis Society, Multiple Sclerosis Society of Canada, the Hilton Foundation and Mr. and Mrs. Eugene Applebaum.

To obtain the latest news releases from Mayo Clinic, go to http://www.mayoclinic.org/news. MayoClinic.com (www.mayoclinic.com) is available as a resource for your health stories. For more on Mayo Clinic research, go to http://www.mayo.edu.

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October 9, 2007 Posted by | Global Health Vision, Global News, Mayo Clinic, MS, Multiple Sclerosis, News, News USA, Ottawa, RSS Feed, Toronto, UK, Washington DC City Feed | 3 Comments

Researchers develop targeted approach to pain management

Contact: Alyssa Kneller
public_affairs@hms.harvard.edu
617-432-0442
Harvard Medical School

BOSTON, Mass. (Oct. 3, 2007)—Imagine an epidural or a shot of Novocain that doesn’t paralyze your legs or make you numb, yet totally blocks your pain. This type of pain management is now within reach. As a result, childbirth, surgery and trips to the dentist might be less traumatic in the future, thanks to researchers at Massachusetts General Hospital (MGH) and Harvard Medical School, who have succeeded in selectively blocking pain-sensing neurons in rats without interfering with other types of neurons.

The pint-sized subjects received injections near their sciatic nerves, which run down their hind limbs, and subsequently lost the ability to feel pain in their paws. But they continued to move normally and react to touch. The injections contained QX-314, a normally inactive derivative of the local anesthetic lidocaine, and capsaicin, the active ingredient in hot peppers. In combination, these chemicals targeted only pain-sensing neurons, preventing them from sending signals to the brain.

“We’ve introduced a local anesthetic selectively into specific populations of neurons,” explains Harvard Medical School Professor Bruce Bean, an author on the paper, which appears in Nature on Oct. 4. “Now we can block the activity of pain-sensing neurons without disrupting other kinds of neurons that control movements or non-painful sensations.”

“We’re optimistic that this method will eventually be applied to humans and change our experience during procedures ranging from knee surgery to tooth extractions,” adds Professor Clifford Woolf of Massachusetts General Hospital, who is senior author on the study.

Despite enormous investments by industry, surgical pain management has changed little since the first successful demonstration of ether general anesthesia at MGH in 1846. General and local anesthetics work by interfering with the excitability of all neurons, not just pain-sensing ones. Thus, these drugs produce dramatic side effects, such as loss of consciousness in the case of general anesthetics or temporary paralysis for local anesthetics.

“We’re offering a targeted approach to pain management that avoids these problems,” says Woolf.

The new work builds on research done since the 1970’s showing how electrical signaling in the nervous system depends on the properties of ion channels, that is, proteins that make pores in the membranes of neurons.

“This project is a perfect illustration of how research trying to understand very basic biological principles can have practical applications,” says Bean.

The new method exploits a membrane-spanning protein called TRPV1, which is unique to pain-sensing neurons. TRPV1 forms a large channel, where molecules can enter and exit the cell. But a “gate” typically blocks this opening. The gate opens when cells are exposed to heat or the chili-pepper ingredient capsaicin. Thus, bathing pain-sensing neurons in capsaicin leaves these channels open, but non-pain sensing neurons are unaffected because they do not possess TRPV1.

The new method then takes advantage of a special property of the lidocaine derivative QX-314. Unlike most local anesthetics, QX-314 can’t penetrate cell membranes to block the excitability of the cell, so it typically lingers outside neurons where it can’t affect them. For this reason it is not used clinically.

When pain-sensing neurons are exposed to capsaicin, however, and the gates guarding the TRPV1 channels disappear, QX-314 can enter the cells and shut them down. But the drug remains outside other types of neurons that do not contain these channels. As a result, these cells fully retain their ability to send and receive signals.

The team first tested their method in the Petri dish. Alexander Binshtok, a postdoctoral researcher in Woolf’s lab, applied capsaicin and QX-314 (separately and in combination) to isolated pain-sensing and other neurons and measured their responses. Indeed, the combination of capsaicin and QX-314 selectively blocked the excitability of pain-sensing neurons, leaving the others unaffected.

Next, Binshtok injected these chemicals into the paws of rats and measured their ability to sense pain by placing them on an uncomfortable heat source. The critters tolerated much more heat than usual. He then injected the chemicals near the sciatic nerve of the animals and pricked their paws with stiff nylon probes. The animals ignored the provocation. Although the rats seemed immune to pain, they continued to move normally and respond to other stimuli, indicating that QX-314 failed to penetrate their motor neurons.

The team must overcome several hurdles before this method can be applied to humans. They must figure out how to open the TRPV1 channels without producing even a transient burning pain before QX-314 enters and blocks the neurons, and they must tinker with the formulation to prolong the effects of the drugs. Both Bean and Woolf are confident they’ll succeed.

“Eventually this method could completely transform surgical and post-surgical analgesia, allowing patients to remain fully alert without experiencing pain or paralysis,” says Woolf. “In fact, the possibilities seem endless. I could even imagine using this method to treat itch, as itch-sensitive neurons fall into the same group as pain-sensing ones.”

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Research in the Woolf lab is supported by the National Institute of Neurological Disorders and Stroke (NINDS) and the National Institute of Dental and Craniofacial Research. Research in the Bean lab is supported by NINDS and the National Institute of General Medical Sciences.

Harvard and MGH have filed patents on this technology platform.

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October 3, 2007 Posted by | Boston, Global Health Vision, Global News, News, News USA, Pain, Pain Management, RSS Feed | 1 Comment

Revealing the workings of ‘Mother Nature’s blowtorch’

Sept. 13, 2007 ANN ARBOR, Mich.—Using atom-level imaging techniques, University of Michigan researchers have revealed important structural details of an enzyme system known as “Mother Nature’s blowtorch” for its role in helping the body efficiently break down many drugs and toxins.

The research has been detailed in a series of papers, the most recent published online this month in the journal BBA Biomembranes.

The system involves two proteins that work cooperatively. The first, cytochrome P450, does the actual work, but only when it gets a boost from the second protein, cytochrome b5. To complicate matters, the two proteins can interact only when both are bound to a cell membrane. That makes it difficult to use traditional techniques to discern the structural details that are crucial to the interaction, said Ayyalusamy Ramamoorthy, who leads the research group.

For instance, X-ray crystallography, often used to determine protein structures, requires separating the molecules from their membrane environment. Because part of cytochrome b5 sticks to the membrane, such separations involve breaking the molecule at the sticking point, which happens to be the part that controls its interaction with cytochrome P450. So while crystallography can offer some information on structure, it can’t provide insights into exactly what goes on between P450 and b5 during their cozy, membrane-bound encounters, Ramamoorthy said.

However, the technique his lab uses—solid state NMR spectroscopy—can produce detailed images of proteins in the membrane environment, not only revealing molecular structure but also showing how a particular protein nestles into the membrane. Cytochrome b5 presented a challenge even to that versatile method, though, because the molecule has three parts that all behave differently: the rigid, sticky portion that buries into the cell membrane, a highly mobile, water-soluble portion, and a less mobile “linker” that connects the other two parts.

But by tweaking their technique, the researchers were able to get high-resolution images of all three portions.

“The challenge was something like having a room full of people and trying to get good photos of every one of them,” said Ramamoorthy, an associate professor of chemistry and Biophysics. “With one picture, you probably can’t do it. But if you say, ‘Everyone over age 50 stand up,’ and you take one picture, and then you ask for another age group and take another picture, and so on, you have a better chance.”

By spinning their samples (or aligning the molecules in the magnetic field), the researchers were able to differentiate parts of the molecule based not on age group, as in the photo analogy, but by mobility. “With the techniques we designed, we were able to observe the rigid portion separately from the highly mobile and less mobile portions,” Ramamoorthy said.

In the first part of the work, published in the Journal of the American Chemical Society in May, the researchers described the membrane-spanning segment of cytochrome b5, revealing for the first time its helical shape and the way it tilts in relation to the membrane. In the new work published in BBA Biomembranes, they determined that once both molecules are bound in the membrane, cytochrome b5 modulates the motion and the structure of cytochrome P450. More work is in progress to determine the detailed high-resolution structures of these two proteins.

Ramamoorthy’s team also is studying other membrane-associated proteins, a group that includes many biologically important molecules.

“These proteins are involved in all major diseases, everywhere in the body, and are therefore primary targets for pharmaceutical applications,” Ramamoorthy said. “In my opinion, solving the structures of membrane proteins should be the highest priority for structural biologists in the coming years.”

Ramamoorthy collaborated on the most recent work with Lucy Waskell, a professor of anesthesiology and a physician at the Department of Veterans Affairs Medical Center.

A leader in this area of research, Ramamoorthy has organized several major international symposia on the field at the University of Michigan, edited a special issue in the journal BBA-Biomembranes, published a number of papers in leading journals, and brought out a book on NMR Spectroscopy of Biological Solids. Ramamoorthy said that this area of research will grow considerably at U-M from implementing plans to set up a high magnetic field solid-state NMR spectrometer facility and an NIH-funded program.

Related Links:

More information on Ramamoorthy

Contact: Nancy Ross-Flanigan
Phone: (734) 647-1853

Related Categories: Science.

See also: News, Health, University of Michigan, Global News

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September 14, 2007 Posted by | Cytochrome b5, Cytochrome P450, Global Health Vision, Global News, Health, journal BBA Biomembranes, News USA, RSS Feed, Science, University of Michigan | Leave a comment

Embryonic stem cells used to grow cartilage

Rice method is first to yield cartilage-like cells, engineer human cartilage

HOUSTON, Sept. 6, 2007 – Rice University biomedical engineers have developed a new technique for growing cartilage from human embryonic stem cells, a method that could be used to grow replacement cartilage for the surgical repair of knee, jaw, hip, and other joints.

“Because native cartilage is unable to heal itself, researchers have long looked for ways to grow replacement cartilage in the lab that could be used to surgically repair injuries,” said lead researcher Kyriacos A. Athanasiou, the Karl F. Hasselmann Professor of Bioengineering. “This research offers a novel approach for producing cartilage-like cells from embryonic stem cells, and it also presents the first method to use such cells to engineer cartilage tissue with significant functional properties.”

The results are available online and slated to appear in the September issue of the journal Stem Cells. The study involved cells from an NIH-sanctioned stem cell line.

Using a series of stimuli, the researchers developed a method of converting the stem cells into cartilage cells. Building upon this work, the researchers then developed a process for using the cartilage cells to make cartilage tissue. The results show that cartilages can be generated that mimic the different types of cartilage found in the human body, such as hyaline articular cartilage — the type of cartilage found in all joints — and fibrocartilage — a type found in the knee meniscus and the jaw joint. Athanasiou said the results are exciting, as they suggest that similar methods may be used to convert the stem cell-derived cartilage cells into robust cartilage sections that can be of clinical usefulness.

Tissue engineers, like those in Athanasiou’s research group, are attempting to unlock the secrets of the human body’s regenerative system to find new ways of growing replacement tissues like muscle, skin, bone and cartilage. Athanasiou’s Musculoskeletal Bioengineering Laboratory at Rice University specializes in growing cartilage tissues.

The idea behind using stem cells for tissue engineering is that these primordial cells have the ability to become more than one type of cell. In all people, there are many types of “adult” stem cells at work. Adult stem cells can replace the blood, bone, skin and other tissues in the body. Stem cells become specific cells based upon a complex series of chemical and biomechanical cues, signals that scientists are just now starting to understand.

Unlike adult stem cells, which can become only a limited number of cell types, embryonic stem cells can theoretically become any type of cell in the human body.

Athanasiou’s group has been one of the most successful in the world at studying cartilage cells and, especially, engineering cartilage tissues. He said that for his research the primary advantage that embryonic stem cells have over adult stem cells is their ability to remain malleable.

“Identifying a readily available cell source has been a major obstacle in cartilage engineering,” Athanasiou said. “We know how to convert adult stem cells into cartilage-like cells. The more problematic issue comes in trying to maintain a ready stock of adult stem cells to work with. These cells have a strong tendency to convert from stem cells into a more specific type of cell, so the clock is always ticking when we work with them.”

By contrast, Athanasiou said his research group has found it easier to grow and maintain a stock of embryonic stem cells. Nonetheless, he is quick to point out that there is no clear choice about which type of stem cell works best for cartilage engineering.

“We don’t know the answer to that,” Athanasiou said. “It’s extremely important that we study all potential cell candidates, and then compare and contrast those studies to find out which works best and under what conditions. Keep in mind that these processes are very complicated, so it may well be that different types of cells work best in different situations.”

Athanasiou began studying embryonic stem cells in 2005. Since funding for the program was limited, he asked two new graduate students in his group if they were interested in pursuing the work as a secondary project to their primary research. Those students, Eugene Koay and Gwen Hoben, are co-authors of the newly published study. Both are enrolled in the Baylor College of Medicine Medical Scientist Training Program, a joint program that allows students to concurrently earn their medical degree from Baylor while undertaking Ph.D. studies at Rice.

“Eugene and Gwen are both outstanding students,” Athanasiou said. “Each earned their undergraduate degree from Rice and each worked in my laboratory as undergraduate students. They have chosen to do this research because they think this may represent the future of regenerative medicine.”

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The research was funded by Rice University.

Contact: Jade Boyd
jadeboyd@rice.edu
713-348-6778
Rice University

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September 7, 2007 Posted by | Global Health Vision, Global News, Health, Health Canada, HIV, Hospital Epidemiology, News UK, News USA, RSS, Science, Stem Cells | Leave a comment

Scientists propose explanation for out-of-body experiences

This release is available in French, Spanish and Japanese.

Using virtual reality goggles to mix up the sensory signals reaching the brain, scientists have induced out-of-body-like experiences in healthy people, suggesting a scientific explanation for a phenomenon often thought to be a figment of the imagination.

The sight of their bodies located somewhere else — thanks to the goggles — plus the feel of their real bodies being touched simultaneously made volunteers sense that they had moved outside of their physical bodies, according to a pair of studies in the 24 August 2007 issue of the journal Science, published by AAAS, the nonprofit science society.

A disconnect between the brain circuits that process both these types of sensory information may thus be responsible for some out-of-body experiences, the researchers say.

Out-of-body experiences, which generally involve the feeling of disembodiment and seeing one’s own body from a location outside the body, can occur in part through drug use, epileptic seizures and other types of brain disturbances.

By projecting a person’s awareness into a virtual body, the techniques used in these studies may be useful for training people to do delicate “teleoperating” tasks, such as performing surgeries remotely. The findings may also remove some of the stigma that patients with neurological disorders may feel about having these experiences, which are frequently attributed to an active imagination or some sort of paranormal phenomenon.

The studies also help solve the age-old question of how we perceive our own bodies.

“I’m interested in why we feel that our selves are inside our bodies — why we have an ‘in-body experience,’ if you like. This has been discussed for centuries in philosophy, but it’s hard to tackle experimentally,” said Science Brevium author Henrik Ehrsson of University College London, in London, and the Karolinska Institute in Stockholm.

Both Ehrsson and another research team, led by Olaf Blanke of the Ecole Polytechique Fédérale de Lausanne (EPFL) and the University Hospital in Geneva, Switzerland, used video cameras and virtual reality goggles to show volunteers images of their own bodies from the perspective of someone behind them. The researchers also touched the volunteers’ bodies, both physically and virtually.

The volunteers in Ehrsson’s study viewed images recorded by the cameras through their headsets. In Blanke and colleagues’ study, the video was converted into holograph-like computer simulations.

Ehrsson had the volunteers watch a plastic rod moving toward a location just below the cameras while their real chests were simultaneously touched in the corresponding spot. Questionnaire responses afterwards indicated that the volunteers felt they were located back where the cameras were placed, watching a dummy or a body that belonged to someone else.

“This experiment suggests that the first-person visual perspective is critically important for the in-body experience. In other words, we feel that our self is located where the eyes are,” Ehrsson said.

Ehrsson also had the volunteers watch a hammer swing down to a point below the camera, as though it were going to “hurt” an unseen portion of the virtual body. Measurements of skin conductance, which reflects emotional responses such as fear, indicated that the volunteers sensed their “selves” had left their physical bodies and moved to the virtual bodies.

Blanke’s team used a similar setup to create out-of-body-like experiences (which they cautioned lacked some aspects of full-blown out-of-body experiences).

After the virtual reality exercise, a researcher would blindfold the volunteers and guide them backward. When the volunteers were asked to return to their original position, they tended to drift toward where they had seen their virtual bodies standing.

Both studies conclude that “multisensory conflict” is a key mechanism underlying out-of-body experiences.

“Brain dysfunctions that interfere with interpreting sensory signals may be responsible for some clinical cases of out-of-body experiences,” Ehrsson said. “Though, whether all out-of-body experiences arise from the same causes is still an open question.”

Bodily self-consciousness may also involve a cognitive dimension – the ability to distinguish between one’s own body and other objects – in addition to sensory signals, Blanke and his coauthors propose.

Supporting this idea, Blanke’s team reports that when the volunteers viewed a human-sized block instead of an image of a human body, they successfully returned to their original standing place, indicating that no out-of-body-like illusion had occurred.

“Full-body consciousness seems to require not just the ‘bottom up’ process of correlating sensory information but also the ‘top down’ knowledge about human bodies,” Blanke said.

Some of the out-of-body experiences that have previously eluded scientific explanation may be related to distorted “full-body perception,” according to Blanke. Virtual reality systems may provide further answers.

“We have decades of intense research on visual perception, but not very much yet on body perception. But that may change, now virtual reality offers a way to manipulate full body perception more systematically and probe out-of-body experiences and bodily self consciousness in a new way,” Blanke said.

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“The Experimental Induction of Out-of-Body Experiences,” by H. Henrik Ehrsson of University College London, in London, UK and Karolinska Institute in Stockholm, Sweden. This research was supported by the Wellcome Trust, the PRESENCCIA project, an EU-funded project under the IST programme, the Human Frontier Science Program, the Swedish Medical Research Council and the Swedish Foundation for Strategic Research.

“Video Ergo Sum: Manipulating Bodily Self-Consciousness,” by Bigna Lenggenhager and Tej Tadi at Ecole Polytechique Fédérale de Lausanne (EPFL), Switzerland; Thomas Metzinger at Johannes Gutenberg-Universität Mainz in Mainz, Germany; and Olaf Blanke at Ecole Polytechique Fédérale de Lausanne (EPFL), Switzerland and University Hospital in Geneva, Switzerland. This research was supported by the Cogito Foundation, the Fondation de Famille Shandoz, the Fondation Odier and the Swiss National Science Foundation.

The American Association for the Advancement of Science (AAAS) is the world’s largest general scientific society, and publisher of the journal Science (www.sciencemag.org). AAAS was founded in 1848, and serves 262 affiliated societies and academies of science, reaching 10 million individuals. Science has the largest paid circulation of any peer-reviewed general science journal in the world, with an estimated total readership of 1 million. The nonprofit AAAS (www.aaas.org) is open to all and fulfills its mission to “advance science and serve society” through initiatives in science policy; international programs; science education; and more. For the latest research news, log onto EurekAlert!, http://www.eurekalert.org, the premier science-news Web site, a service of AAAS.

Contact: Natasha Pinol
npinol@aaas.org
202-326-7088
American Association for the Advancement of Science

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August 26, 2007 Posted by | Global Health Vision, Global News, Karolinska Institute in Stockholm, News, News France, News Switzerland, News USA, Science, University College London, University Hospital in Geneva | Leave a comment

Quantum light beams good for fast technology

Australian and French scientists have made another breakthrough in the technology that will drive next generation computers and teleportation.

The researchers have successfully superposed light beams, which produces a state that appears to be both on and off at once.

Light beams that are simultaneously on and off are vital for the next-generation super computers which should be faster than current computers based on bits, that are either on or off.

Previously, only smaller light particles had been superposed and the group has also proved a quantum physics theory known as Schrödinger’s cat.

This theory, named after an Austrian physicist Erwin Schrödinger, proposed that a large object such as a cat could be simultaneously alive and dead.

Researchers from The University of Queensland and University of Paris South have published the latest breakthrough in the international journal NATURE.

UQ Centre for Quantum Computer Technology researcher Dr Hyunseok Jeong devised the scheme to generate and superpose the beams which was tested and proved by his French collaborators.

Dr Jeong said his group used special lasers, crystals, photon detectors, half-mirrors and other optical devices to generate and measure the superposition of light beams.

“It has been known to be extremely hard to generate Schrödinger cat states, particularly with traveling light,” Dr Jeong said.

“Even though one could generate such Schrodinger cat states, it would be extremely hard to observe them because in a very short time, they would be reduced to either alive or dead states.”

He said his group’s research findings would help speed up the development of quantum information technologies such as quantum computers, quantum cryptography and quantum teleportation.

“Using Schrödinger cat states, quantum teleportation may be performed with nearly 100 percent success probability.”

Contact: Dr. Jeong
communications@uq.edu.au
61-733-469-728
Research Australia

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August 24, 2007 Posted by | Global Health Vision, Global News, News, News Australia, News France, News USA | Leave a comment

Can cancer drugs combine forces?

Individuals with chronic myeloid leukemia (CML) are treated first with a drug known as imatinib (Gleevec), which targets the protein known to cause the cancer (BCR-ABL). If their disease returns, because BCR-ABL mutants emerge that are resistant to the effects of imatinib, individuals are treated with a drug known as dasatinib (SPRYCEL), which targets BCR-ABL in a different way. However, patients that relapse after treatment with dasatinib, because BCR-ABL mutants emerge that are resistant to the effects of this drug, are now beginning to be seen in the clinic. Researchers from Memorial Sloan-Kettering Cancer Center, New York, now suggest that treating patients with a combination of the drugs might decrease the chance of the cancer returning, or at the very least increase the time before a relapse occurs

In the study, which appears online on August 16 in advance of publication in the September print issue of the Journal of Clinical Investigation, Charles Sawyers and colleagues show that 2 of 12 patients whose cancer had returned after treatment with dasatinib responded to retreatment with imatinib. Analysis of the BCR-ABL proteins from these patients revealed that their BCR-ABL had only the dasatinib-resistance mutation. By contrast, the BCR-ABL proteins of the other patients had either a single mutation that rendered the protein resistant to both dasatinib and imatinib or had two mutations, one rendering the protein resistant to imatinib and one rendering the protein resistant to dasatinib. A third drug that can target dasatinib- and imatinib-resitant BCR-ABL is currently in clinical trials. The authors therefore suggest that rather than treating CML patients with the drugs that target BCR-ABL sequentially, they should receive all the drugs when they are first diagnosed with the disease so that the emergence of the drug-resistant forms of BCR-ABL might be prevented, or at least delayed.

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TITLE: Sequential ABL kinase inhibitor therapy selects for compound drug-resistant BCR-ABL mutations with altered oncogenic potency

AUTHOR CONTACT: Charles L. Sawyers Memorial Sloan-Kettering Cancer Center, New York, New York, USA. Phone: (646) 888-2138; Fax: (646) 888-2595; E-mail: sawyersc@mskcc.org.

View the PDF of this article at: https://www.the-jci.org/article.php?id=30890

Contact: Karen Honey
press_releases@the-jci.org
215-573-1850
Journal of Clinical Investigation

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August 16, 2007 Posted by | Cancer, Global Health Vision, Global News, Health, Leukemia, News UK, News USA | 1 Comment