Showing posts with label HEALTH. Show all posts
Showing posts with label HEALTH. Show all posts

Monday, November 5, 2007

A Warning !!!! :Chemical weapons create toxic waste nightmare


We want environment for us , for next generation , so in all espect we have to think the reaction of thing or policies we are innitiating , have to clear about CONFLICT: EVOLUTION AND FUTURE OF COMBAT AND WEAPONS


MEETING in the Hague next week, the signatories to the Chemical Weapons Convention (CWC) will celebrate the fact that Albania and the UK have destroyed their last chemical weapons and that India and South Korea are almost done. But there will be an elephant in the room: in their scramble to destroy weapons by a 2012 deadline, Russia and the US, which possess over 95 per cent of the world's chemical weapons, are creating thousands of tonnes of a nasty, toxic residue that they are having trouble disposing of.


Chemical weapons can be incinerated directly. But fearing a release of toxic gases, half the American and all the Russian weapons sites are breaking down the lethal molecules by adding alkali, a technique called hydrolysis. This creates a new problem: how to dispose of the resulting toxic soup, known as the hydrolysate.




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Sunday, November 4, 2007

Neurology : Big MIT contingent at Society for Neuroscience meeting


MIT's excellence in brain research will be showcased next week in San Diego as Institute scientists give five of the 24 invited talks at the annual meeting of the Society for Neuroscience.


"This is an extremely high representation from one institution," said Mriganka Sur, chair of the Department of Brain and Cognitive Sciences and one of the MIT speakers.


The Society for Neuroscience is the world's largest organization of scientists devoted to studying the brain. Some 30,000 people are expected to attend the group's annual -conference.


One of the five MIT researchers, H. Sebastian Seung, professor of computational neuroscience, will give the Presidential Special Lecture on "The Once and Future Science of Neural Networks." In his talk, Seung will describe a revolutionary new way to create a nanoscale-level map of the brain's axon and dendrite "wires" based on actual human brain tissue. This cutting-edge field, called computational neuroanatomy, is expected to confirm or deny long-held basic assumptions about how the brain works.


Seung's laboratory is one of a handful in the world working on a new initiative called "the connectome," which seeks to translate three-dimensional images of the brain at nanoscale resolution into a circuit diagram of all the brain's neurons and synaptic connections.


Current models of the human brain revolve around the belief that synapses' connections determine brain function and that synaptic plasticity underlies learning and memory. But now, "we have seen tantalizing hints that these basic ideas are at least partially true, as well as examples where they fall short," said Seung, who also is a Howard Hughes Medical Institute (HHMI) investigator. "The advent of high-throughput methods for gathering neurophysiological and neuroanatomical data will transform our ability to test the foundations of neural network theory."


The other MIT speakers and their topics are:


Mark F. Bear, Picower Professor of Neuroscience, director of the Picower Institute for Learning and Memory and HHMI investigator, will speak on "Modification of Cerebral Cortex by Experience." More than four decades of research on how synapses are formed, strengthened, weakened and lost under the influence of sensory experience have culminated in a deep understanding of the mechanisms for this synaptic plasticity. The knowledge ranges from novel insights into the pathophysiology of developmental disorders to new strategies to enhance perceptual learning and recovery from environmental deprivation, he said.


Li-Huei Tsai, Picower Professor of Neuroscience and HHMI investigator, will speak on "Mechanisms Underlying Prevention of Cognitive Decline and Restoration of Memory in Age-Dependent Neurodegenerative Disorders." The number of people with Alzheimer's disease is expected to triple from 5 to 15 million by the year 2050. Age-dependent neurodegeneration and dementia is currently incurable. Tsai's lecture will focus on recent research of cellular mechanisms, including synaptic plasticity, which have provided models for understanding neurodegeneration and memory loss. A particular emphasis will be placed on new strategies to prevent decline or restore memories.


Mriganka Sur, Sherman Fairchild Professor of Neuroscience, will speak on "New Approaches for Revealing Cortical Function: Plasticity and Dynamics of Visual Cortex Networks." Sur will talk about how a range of novel tools, including in vivo high-resolution imaging of neurons, synapses and astrocytes, cell-specific markers and genetically engineered probes, along with new experimental paradigms, are transforming the analysis of cortical networks.


Susan L. Lindquist, professor of biology, member of the Whitehead Institute for Biomedical Research and HHMI investigator, will give the Albert and Ellen Grass Lecture. Proteins begin as long strings that must fold precisely. The misfolding of certain amyloidogenic proteins associated with neuronal cells is responsible for certain neurodegenerative diseases. Surprisingly, she said, similar changes in the folding of other proteins may have beneficial effects in learning and memory. Lindquist's lecture will investigate therapeutic strategies to control the folding of amyloidogenic proteins.




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Monday, October 29, 2007

Public Health Risks from Climate Change are Key Concern Commentsby Professor Jonathan A. Patz


Message not to be Lost in Debate: Public Health Risks from Climate Change are Key Concern - Oct 26, 2007


Comment by Professor Jonathan A. Patz, University of Wisconsin, Madison


With all the attention over the Bush Administration's mishandling of senate testimony by CDC Director, Julie Gerberding, I fear that the central clear message is being overshadowed by the (albeit errant) procedural aspects of the situation. Serving as a Lead Author for the United Nations Intergovernmental Panel on Climate Change (IPCC) reports of 1995, 1998, 2001, and 2007 (and Health Co-Chair for the US National Assessment on Climate Change) I can reaffirm that the original CDC testimony was scientifically accurate and consistent with IPCC findings.


But more than enough press has focused on the handling of the testimony, and not enough on the important messages that Congress and the American public need to know about Global Warming. These are:


1) Our public's health is indeed at risk from the effects of climate change acting via numerous hazardous exposure pathways, including: more intense and frequent heat waves and storms; ozone smog pollution and increased pollen allergens; insect-borne and water-borne infectious diseases; and disease risks from outside the US - afterall, we live in a globalized world. Some benefits from reduced cold and some decline in certain diseases can be expected, however, the scientific assessments have consistently found that, on balance, the health risks outweigh the benefits.


2) The Department of Health and Human Services, that includes CDC and NIH, are responsible for protecting the health of the American public. To the extent that extremes of climate can have broad population-wide impacts, neither the CDC nor NIH have directed adequate resources to address climate change, and to date, funding has been minimal compared to the size of the health threat.


3) There are potentially large opportunities and co-benefits in addressing the health risks of global warming. Certainly, our public health infrastructure must be strengthened, e.g, fortify water supply systems, heat and storm early warning and response programs, and enhance disease modeling and surveillance. However, energy policy now becomes one and the same as public health policy. Reducing fossil fuel burning will: (a) further reduce air pollution, (b) improve our fitness (e.g., if urban transportation planning allows for more Americans to travel by foot or bike, than by car), and (c) lessen potential greenhouse warming.


In short, the challenges posed by climate change urgently demand improving public health infrastructure AND energy conservation / urban planning policies - as such, climate change can present both enormous health risks and opportunities. But without funding from Congress to address climate change, CDC has its hands tied.


Web Resources:
Global & Sustainable Environmental Health at the University of Wisconsin, Madison
http://www.sage.wisc.edu/pages/health.html


Website for Middle School teachers and students, and the general public
http://www.ecohealth101.org




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Brain acts diffrent For Creative And Noncreative Thinkers


How brain acts for crealtivity ?


Why do some people solve problems more creatively than others? Are people who think creatively different from those who tend to think in a more methodical fashion?


These questions are part of a long-standing debate, with some researchers arguing that what we call "creative thought" and "noncreative thought" are not basically different. If this is the case, then people who are thought of as creative do not really think in a fundamentally different way from those who are thought of as noncreative. On the other side of this debate, some researchers have argued that creative thought is fundamentally different from other forms of thought. If this is true, then those who tend to think creatively really are somehow different.


A new study led by John Kounios, professor of Psychology at Drexel University and Mark Jung-Beeman of Northwestern University answers these questions by comparing the brain activity of creative and noncreative problem solvers. The study, published in the journal Neuropsychologia, reveals a distinct pattern of brain activity, even at rest, in people who tend to solve problems with a sudden creative insight -- an "Aha! Moment" - compared to people who tend to solve problems more methodically.


At the beginning of the study, participants relaxed quietly for seven minutes while their electroencephalograms (EEGs) were recorded to show their brain activity. The participants were not given any task to perform and were told they could think about whatever they wanted to think about. Later, they were asked to solve a series of anagrams - scrambled letters that can be rearranged to form words [MPXAELE = EXAMPLE]. These can be solved by deliberately and methodically trying out different letter combinations, or they can be solved with a sudden insight or "Aha!" in which the solution pops into awareness. After each successful solution, participants indicated in which way the solution had come to them.


The participants were then divided into two groups - those who reported solving the problems mostly by sudden insight, and those who reported solving the problems more methodically - and resting-state brain activity for these groups was compared. As predicted, the two groups displayed strikingly different patterns of brain activity during the resting period at the beginning of the experiment - before they knew that they would have to solve problems or even knew what the study was about.


One difference was that the creative solvers exhibited greater activity in several regions of the right hemisphere. Previous research has suggested that the right hemisphere of the brain plays a special role in solving problems with creative insight, likely due to right-hemisphere involvement in the processing of loose or "remote" associations between the elements of a problem, which is understood to be an important component of creative thought. The current study shows that greater right-hemisphere activity occurs even during a "resting" state in those with a tendency to solve problems by creative insight. This finding suggests that even the spontaneous thought of creative individuals, such as in their daydreams, contains more remote associations.


Second, creative and methodical solvers exhibited different activity in areas of the brain that process visual information. The pattern of "alpha" and "beta" brainwaves in creative solvers was consistent with diffuse rather than focused visual attention. This may allow creative individuals to broadly sample the environment for experiences that can trigger remote associations to produce an Aha! Moment.


For example, a glimpse of an advertisement on a billboard or a word spoken in an overheard conversation could spark an association that leads to a solution. In contrast, the more focused attention of methodical solvers reduces their distractibility, allowing them to effectively solve problems for which the solution strategy is already known, as would be the case for balancing a checkbook or baking a cake using a known recipe.


Thus, the new study shows that basic differences in brain activity between creative and methodical problem solvers exist and are evident even when these individuals are not working on a problem. According to Kounios, "Problem solving, whether creative or methodical, doesn't begin from scratch when a person starts to work on a problem. His or her pre-existing brain-state biases a person to use a creative or a methodical strategy."


In addition to contributing to current knowledge about the neural basis of creativity, this study suggests the possible development of new brain imaging techniques for assessing potential for creative thought, and for assessing the effectiveness of methods for training individuals to think creatively.


Journal reference: Kounios, J., Fleck, J.I., Green, D.L., Payne, L., Stevenson, J.L., Bowden, E.M., & Jung-Beeman, M. The origins of insight in resting-state brain activity, Neuropsychologia (2007), doi:10.1016/j.neuropsychologia.2007.07.013


sourced Drexel University.




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Sunday, October 28, 2007

Men who smoke cigarettes run an increased risk of experiencing erectile dysfunction


A team of researchers led by Jiang He, Professor of Epidemiology at the Tulane University School of Public Health and Tropical Medicine, examined the association between cigarette smoking and erectile dysfunction in a 2000-2001 study in China involving 7,684 men. The researchers used questionnaires to assess the status of cigarette smoking and erectile dysfunction. Those surveyed were men between the ages of 35-74 who did not have vascular disease.


The team found that there was a significant statistical link between the number of cigarettes that men smoked and the likelihood they would experience erectile dysfunction. The association between smoking and erectile dysfunction was even stronger in participants with diabetes. An estimated 22.7 percent of erectile dysfunction cases among Chinese men might be attributable to cigarette smoking, says the study.


Although erectile dysfunction is not a life-threatening condition, it compromises well-being and quality of life. The Tulane study results suggest that smoking prevention should be an important approach for reducing the risk of erectile dysfunction




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Study :organic really is better for health



THE biggest study into organic food has found that it is more nutritious than ordinary produce and may help to lengthen people's lives.


The evidence from the £12m four-year project will end years of debate and is likely to overturn government advice that eating organic food is no more than a lifestyle choice.


The study found that organic fruit and vegetables contained as much as 40% more antioxidants, which scientists believe can cut the risk of cancer and heart disease, Britain's biggest killers. They also had higher levels of beneficial minerals such as iron and zinc.


Professor Carlo Leifert, the co-ordinator of the European Union-funded project, said the differences were so marked that organic produce would help to increase the nutrient intake of people not eating the recommended five portions a day of fruit and vegetables. "If you have just 20% more antioxidants and you can't get your kids to do five a day, then you might just be okay with four a day," he said.


This weekend the Food Standards Agency confirmed that it was reviewing the evidence before deciding whether to change its advice. Ministers and the agency have said there are no significant differences between organic and ordinary produce.


Researchers grew fruit and vegetables and reared cattle on adjacent organic and nonorganic sites on a 725-acre farm attached to Newcastle University, and at other sites in Europe. They found that levels of antioxidants in milk from organic herds were up to 90% higher than in milk from conventional herds.


As well as finding up to 40% more antioxidants in organic vegetables, they also found that organic tomatoes had significantly higher levels of antioxidants, including flavo-noids thought to reduce coronary heart disease.





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Thursday, October 18, 2007

Acupuncture Reduces Pain :Acupuncture Works for Back Pain


Using acupuncture before and during surgery significantly reduces the level of pain and the amount of potent painkillers needed by patients after the surgery is over, according to Duke University Medical Center anesthesiologists who combined data from 15 small randomized acupuncture clinical trials.


"While the amount of opioids needed for patients who received acupuncture was much lower than those who did not have acupuncture, the most important outcome for the patient is the reduction of the side effects associated with opioids," said Tong Joo (T.J.) Gan, M.D., a Duke anesthesiologist who presented the results of the analysis at the annual scientific conference of the American Society for Anesthesiology in San Francisco. "These side effects can negatively impact a patient's recovery from surgery and lengthen the time spent in the hospital."


Based on the results of this analysis, Gan recommends that acupuncture should be considered a viable option for pain control in surgery patients.


Patients who received acupuncture had significantly lower risk of developing most common side effects associated with opioid drugs compared with control: 1.5 times lower rates of nausea, 1.3 times fewer incidences of severe itching, 1.6 times fewer reports of dizziness and 3.5 times fewer cases of urinary retention.


Opioids are a class of medications that act on the body much like morphine. While they are effective in controlling pain, the side effects of the drugs often influence a patient's recovery from, and satisfaction with, their surgery, Gan said.


The results of this study add to the growing body of evidence that acupuncture can play an effective role in improving the quality of the surgical experience, Gan added. Numerous studies, some conducted by Gan, have demonstrated that acupuncture can also be more effective than current medications in lessening the occurrence of post operative nausea and vomiting, the most common side effect experienced by patients after surgery.


"Acupuncture is slowly becoming more accepted by American physicians, but it is still underutilized," Gan said. "Studies like this, which show that there is a benefit to using it, should help give physicians sitting on the fence the data they need to integrate acupuncture into their routine care of surgery patients."


Acupuncture has the added benefits of being inexpensive, with virtually no side effects, when done by properly trained personnel, Gan added.


The Chinese have been using acupuncture for more than 5,000 years for the treatment of a variety of ailments, including headaches, gastrointestinal disorders and arthritis. According to Chinese healing practices, there are about 360 specific points along 14 different lines, or meridians, that course throughout the body just under the skin.


"The Chinese believe that our vital energy, known as chi, flows throughout the body along these meridians," Gan explained. "While healthiness is a state where the chi is in balance, unhealthiness or disease state arises from either too much or too little chi, or a blockage in the flow of the chi."


Different bodily locations or organs have their own distinct acupuncture points that are the targets for the acupuncturist. For example, a point just below the wrist is the common target for women undergoing breast procedures to prevent nausea and vomiting, another point at the back of the hand is effective in reducing pain.


While it is not completely known why or how acupuncture works, recent research seems to point to its ability to stimulate the release of hormones or the body's own painkillers, known as endorphins, Gan said. He is now conducting studies to determine the exact mechanism behind acupuncture's effects.


Other members of the research team included Yanxia Sun, John Dubose and Ashraf Habib. The meta-analysis was supported by Duke's Department of Anesthesiology.




Acupuncture Works for Back Pain


Fake acupuncture works nearly as well as the real thing for low back pain, and either kind performs much better than usual care, German researchers have found. Almost half the patients treated with acupuncture needles felt relief that lasted months. In contrast, only about a quarter of the patients receiving medications and other Western medical treatments felt better.

Even fake acupuncture worked better than conventional care, leading researchers to wonder whether pain relief came from the body's reactions to any thin needle pricks or, possibly, the placebo effect.

"Acupuncture represents a highly promising and effective treatment option for chronic back pain," study co-author Dr. Heinz Endres of Ruhr University Bochum in Bochum, Germany, said in an e-mail. "Patients experienced not only reduced pain intensity, but also reported improvements in the disability that often results from back pain and therefore in their quality of life."

Although the study was not designed to determine how acupuncture works, Endres said, its findings are in line with a theory that pain messages to the brain can be blocked by competing stimuli.

Positive expectations the patients held about acupuncture - or negative expectations about conventional medicine - also could have led to a placebo effect and explain the findings, he said.

In the largest experiment on acupuncture for back pain to date, more than 1,100 patients were randomly assigned to receive either acupuncture, sham acupuncture or conventional therapy. For the sham acupuncture, needles were inserted, but not as deeply as for the real thing. The sham acupuncture also did not insert needles in traditional acupuncture points on the body and the needles were not manually moved and rotated.

After six months, patients answered questions about pain and functional ability and their scores determined how well each of the therapies worked.

In the real acupuncture group, 47 percent of patients improved. In the sham acupuncture group, 44 percent did. In the usual care group, 27 percent got relief.

"We don't understand the mechanisms of these so-called alternative treatments, but that doesn't mean they don't work," said Dr. James Young of Chicago's Rush University Medical Center, who wasn't involved in the research. Young often treats low back pain with acupuncture, combined with exercises and stretches.

Chinese medicine holds that there are hundreds of points on the body that link to invisible pathways for the body's vital energy, or qi. The theory goes that stimulating the correct points with acupuncture needles can release blocked qi.

Dr. Brian Berman, the University of Maryland's director of complementary medicine, said the real and the sham acupuncture may have worked for reasons that can be explained in Western terms: by changing the way the brain processes pain signals or by releasing natural painkillers in the body.

In the study, the conventional treatment included many methods: painkillers, injections, physical therapy, massage, heat therapy or other treatments. Like the acupuncture patients, the patients getting usual care received about 10 sessions of 30 minutes each.

The study, appearing in Monday's Archives of Internal Medicine, used a broad definition for low back pain, but ruled out people with back pain caused by spinal fractures, tumors, scoliosis and pregnancy.

Funding came from German health insurance companies, and the findings already have led to more coverage in Germany of acupuncture.





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Wednesday, October 17, 2007

Faster, More Efficient Method For Detecting Illegal Steroids In Urine


To protect the growing concerns about sports "doping," researchers in Indiana and China report development of a faster and more efficient method for detecting the presence of illegal anabolic steroids in urine.




This instrument provides a faster, more efficient method for detecting illegal steroids in urine. (Credit: Courtesy of Zheng Ouyang, Purdue University)


Their new method, which takes only a few seconds and involves no time-consuming sample preparation, will be described in Analytical Chemistry.

The study notes that use of banned substances by professional athletes to build muscle and gain a competitive advantage is a growing problem in sports such as track and field, baseball, football and cycling. Although effective methods exist for detecting the presence of illegal steroids in urine, current methods are time-consuming and involve cumbersome preparation steps.


Zheng Ouyang, R. Graham Cooks, and colleagues developed a new steroid-testing method that combines two state-of-the-art testing techniques called desorption electrospray ionization (DESI) and tandem mass spectrometry. In laboratory studies, the researchers used it to analyze fresh urine samples for the presence of tiny amounts of seven different anabolic steroids. The new method accurately identified the steroids in only a few seconds using only a single drop of urine, they say.


Reference: "Rapid Screening of Anabolic Steroids in Urine by Reactive Desorption Electrospray Ionization" Analytical Chemistry, November 1, 2007.


Source :American Chemical Society.




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Blood may help us think : Can we develop our thinks?


What gives us innovative power? what makes us active ? Thinkig!!


MIT scientists propose that blood may help us think, in addition to its well-known role as the conveyor of fuel and oxygen to brain cells.


"We hypothesize that blood actively modulates how neurons process information," Christopher Moore, a principal investigator in the McGovern Institute for Brain Research at MIT, explained in an invited review in the October issue of the Journal of Neurophysiology. "Many lines of evidence suggest that blood does something more interesting than just delivering supplies. If it does modulate how neurons relay signals, that changes how we think the brain works."


According to Moore's Hemo-Neural Hypothesis, blood is not just a physiological support system but actually helps control brain activity. Specifically, localized changes in blood flow affect the activity of nearby neurons, changing how they transmit signals to each other and hence regulating information flow throughout the brain. Ongoing studies in Moore's laboratory support this view, showing that blood flow does modulate individual neurons.


Moore's theory has implications for understanding brain diseases such as Alzheimer's, schizophrenia, multiple sclerosis and epilepsy. "Many neurological and psychiatric diseases have associated changes in the vasculature," said Moore, who is also an assistant professor in MIT's Department of Brain and Cognitive Sciences.


"Most people assume the symptoms of these diseases are a secondary consequence of damage to the neurons. But we propose that they may also be a causative factor in the disease process, and that insight suggests entirely new treatments." For example, in epilepsy people often have abnormal blood vessels in the brain region where the seizures occur, and the hypothesis suggests this abnormal flow may induce epileptic onset. If so, drugs that affect blood flow may provide an alternative to current therapies.


The hypothesis also has important implications for functional magnetic resonance imaging, or fMRI, a widely used brain scanning method that indicates local changes in blood flow. "Scientists looking at fMRI currently regard blood flow and volume changes as a secondary process that only provides read-out of neural activity," explained Rosa Cao, a graduate student in Moore's lab and co-author of the paper. "If blood flow shapes neural activity and behavior, then fMRI is actually imaging a key contributor to information processing."


Again, studies in Moore's lab support this interpretation. For example, his fMRI studies of the sensory homunculus--the brain's detailed map of body parts like fingers, toes, arms, and legs--show that when more blood flows to the area representing the fingertip, people more readily perceive a light tap on the finger. This suggests that blood affects the function of this brain region and that information about blood flow can predict future brain activity. This finding does not undermine prior studies, but adds another, richer layer to their interpretation and makes fMRI an even more useful tool than it already is.


How could blood flow affect brain activity? Blood contains diffusible factors that could leak out of vessels to affect neural activity, and changes to blood volume could affect the concentration of these factors. Also, neurons and support cells called glia may react to the mechanical forces of blood vessels expanding and contracting. In addition, blood influences the temperature of brain tissue, which affects neural activity.


To Moore's knowledge, the Hemo-Neural Hypothesis offers an entirely new way of looking at the brain. "No one ever includes blood flow in models of information processing in the brain," he said. One historical exception is the philosopher Aristotle, who thought the circulatory system was responsible for thoughts and emotions. Perhaps the ancient Greeks were on to something.


This work was funded by Thomas F. Peterson, the Mitsui Foundation and the McGovern Institute for Brain Research at MIT.




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Monday, October 15, 2007

Institute of Medicine elects Brown


Emery N. Brown, M.D., a professor in the Harvard-MIT Division of Health Sciences and Technology and in the Department of Brain and Cognitive Sciences, has been elected to the Institute of Medicine.


He is among 65 new members of the Washington, D.C.-based institute, raising its total active membership to 1,538.


The Institute of Medicine is one of the four national academies, along with the National Academy of Sciences, the National Academy of Engineering and the National Research Council. It serves as a national resource for independent, scientifically informed analysis and recommendations on human health issues.


A primary focus of Brown's research is the development of statistical methods and signal-processing algorithms for neuroscience data analysis. A new research direction in his laboratory is to use a systems neuroscience approach to study how the state of general anesthesia is induced and maintained. The long-term goal of this research is to establish a neurophysiological definition of anesthesia, and to develop safer, site-specific anesthetic drugs and neurophysiologically based methods for measuring the depth of anesthesia.


Brown is also affiliated with Massachusetts General Hospital.




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Brain's attention fast to fearful looks : study


Horrified expression is a sure-fire attention getter, U.S. researchers said on Sunday, based on a study of how fast people process facial expressions.


They believe fearful facial expressions make a beeline to the alarm center of the brain known as the amygdala, cuing humans to potential threats.


Of emotional information, a horrified expression is an easy way to get others' attention because people recognize the expression faster than any other, .


The finding is based on a study of how fast people process facial expressions, namely, fearful, neutral and happy expressions.


The researchers think that a region of the brain called the amygdala, which has a primary role in processing emotional information, shortcuts the normal brain pathway for processing visual images and causes the fearful face to jump out more quickly.


"We think what is happening with fear is that this is a critical threat signal for us," said David Zald, associate professor of psychology at Vanderbilt University in Tennessee. "Fear tells you something is wrong and you need to pay attention."


Zald and his colleagues think the expression of the eyes in a fearful face holds the key to its quick recognition.


"Fearful eyes are a particular shape, where you get more of the whites of the eye showing," Zald said. "That may be the sort of simple feature that the amygdala can pick up on, because it's only getting a fairly crude representation."


The fast recognition of fear may be an evolutionary survival mechanism geared to direct attention to signals of potential threats in the environment.


Happy expressions were the slowest to be recognized according to the study, which also fits into the evolutionary explanation.


"What we believe is happening is that the happy faces signal safety," Zald said. "If something is safe, you don't have to pay attention to it."




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Friday, October 12, 2007

Nodiamonds effective at delivering chemotherapy drugs to cells without the negative effects


Researchers have shown that nanodiamonds -- much like the carbon structure as that of a sparkling 14 karat diamond but on a much smaller scale -- are very effective at delivering chemotherapy drugs to cells without the negative effects associated with current drug delivery agents.
Their study, published online by the journal Nano Letters, is the first to demonstrate the use of nanodiamonds, a new class of nanomaterials, in biomedicine. In addition to delivering cancer drugs, the model could be used for other applications, such as fighting tuberculosis or viral infections, say the researchers.


More


Nanodiamonds promise to play a significant role in improving cancer treatment by limiting uncontrolled exposure of toxic drugs to the body. The research team reports that aggregated clusters of nanodiamonds were shown to be ideal for carrying a chemotherapy drug and shielding it from normal cells so as not to kill them, releasing the drug slowly only after it reached its cellular target.


Another advantage of the material, confirmed by a series of genetic studies also reported in the paper, is that nanodiamonds do not cause cell inflammation once the drug has been released and only bare diamonds are left. Materials currently used for drug delivery can cause inflammation, a serious complication that can predispose a patient to cancer, block the activity of cancer drugs and even promote tumor growth.


"There are a lot of materials that can deliver drugs well, but we need to look at what happens after drug delivery," said Dean Ho, assistant professor of biomedical engineering and mechanical engineering at Northwestern's McCormick School of Engineering and Applied Science, who led the research. "How do cells react to an artificial material left in the body? Nanodiamonds are highly ordered structures, which cells like. If they didn't, cells would become inflamed. From a patient's perspective, this is very important. And that's why clinicians are interested in our work."


"Novel drug delivery systems, such as the one being developed by Dean and his team, hold great promise in cancer therapeutics," said Steven Rosen, M.D., director of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University and Genevieve E. Teuton Professor of Medicine at Northwestern's Feinberg School of Medicine. "We anticipate they will allow for more sophisticated means of targeting cancer cells while sparing healthy cells from a drug's toxicity."


To make the material effective, Ho and his colleagues manipulated single nanodiamonds, each only two nanometers in diameter, to form aggregated clusters of nanodiamonds, ranging from 50 to 100 nanometers in diameter. The drug, loaded onto the surface of the individual diamonds, is not active when the nanodiamonds are aggregated; it only becomes active when the cluster reaches its target, breaks apart and slowly releases the drug. (With a diameter of two to eight nanometers, hundreds of thousands of diamonds could fit onto the head of a pin.)


"The nanodiamond cluster provides a powerful release in a localized place -- an effective but less toxic delivery method," said co-author Eric Pierstorff, a molecular biologist and post-doctoral fellow in Ho's research group. Because of the large amount of available surface area, the clusters can carry a large amount of drug, nearly five times the amount of drug carried by conventional materials.


Liposomes and polymersomes, both spherical nanoparticles, currently are used for drug delivery. While effective, they are essentially hollow spheres loaded with an active drug ready to kill any cells, even healthy cells that are encountered as they travel to their target. Liposomes and polymersomes also are very large, about 100 times the size of nanodiamonds -- SUVs compared to the nimble nanodiamond clusters that can circulate throughout the body and penetrate cell membranes more easily.


Unlike many of the emerging nanoparticles, nanodiamonds are soluble in water, making them clinically important. "Five years ago while working in Japan, I first encountered nanodiamonds and saw it was a very soluble material," said materials scientist Houjin Huang, lead author of the paper and also a post-doctoral fellow in Ho's group. "I thought nanodiamonds might be useful in electronics, but I didn't find any applications. Then I moved to Northwestern to join Dean and his team because they are capable of engineering a broad range of devices and materials that interface well with biological tissue. Here I've focused on using nanodiamonds for biomedical applications, where we've found success.


"Nanodiamonds are very special," said Huang. "They are extremely stable, and you can do a lot of chemistry on the surface, to further functionalize them for targeting purposes. In addition to functionality, they also offer safety -- the first priority to consider for clinical purposes. It's very rare to have a nanomaterial that offers both."


"It's about optimizing the advantages of a material," said Ho, a member of the Lurie Cancer Center. "Our team was the first to forge this area -- applying nanodiamonds to drug delivery. We've talked to a lot of clinicians and described nanodiamonds and what they can do. I ask, 'Is that useful to you?' They reply, 'Yes, by all means.'"


For their study, Ho and his team used living murine macrophage cells, human colorectal carcinoma cells and doxorubicin hydrochloride, a widely used chemotherapy drug. The drug was successfully loaded onto the nanodiamond clusters, which efficiently ferried the drug inside the cells. Once inside, the clusters broke up and slowly released the drug.


In the genetic studies, the researchers exposed cells to the bare nanodiamonds (no drug was present) and analyzed three genes associated with inflammation and one gene for apoptosis, or cell death, to see how the cells reacted to the foreign material. Looking into the circuitry of the cell, they found no toxicity or inflammation long term and a lack of cell death. In fact, the cells grew well in the presence of the nanodiamond material.





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Wednesday, September 19, 2007

Stem cells show potential to repair lungs in mice


Stem cells show potential to repair lungs in mice


British researchers have successfully implanted lung cells grown from embryonic stem cells into the lungs of mice in a move that may one day provide treatments for humans with severe breathing problems.


Until now, stem cells have been seen as a promising avenue for conditions like diabetes and Parkinson's disease, but respiratory ailments have not featured because of the highly complex nature of lung tissue.


Sile Lane of Imperial College, London, said the new research was a significant advance, although it would be many years before the technology was ready for testing on people.


"Our study shows that embryonic stem cells really do have the capacity to recolonize damaged lungs," she said.


Lane told the European Respiratory Society annual congress in Stockholm that cells injected into the tail veins of mice successfully migrated to the lungs within two days, with no sign of spread to other organs.


If a similar technique works using human embryonic stem cells, it might eventually offer an alternative to difficult and costly lung transplants, as well as helping patients with serious lung damage caused by disease or accident.


Scientists will not be rushing into the clinic, however.


"Stem cells are controversial and they haven't yet been proved safe, so we don't yet know what might happen if we put them into people," Lane said in a telephone interview



"And lung tissue is complicated architecturally and cellularly. We're going to need all kinds of scaffolds to replicate the 3-D structure."


Stem cells are the body's master cell, acting as a source for the various cells and tissues in the body. Those taken from days-old embryos, called embryonic stem cells, are the most malleable and can produce all of the cell types.


Their use is controversial because some people oppose the destruction of a human embryo. Because they are so immature, it is also difficult to control what kinds of cells they produce, leading to fears they might cause serious damage or cancer.


Lane said it was possible that stem cells could have an important role to play in lung disease even if they were not implanted into the body.


One option would be to incorporate them into gas exchangers, machines which oxygenate the blood outside the body while patients are awaiting surgery, she said.


MORE NEWS.....


Stem Cells Show Potential for Treatment of Some Lung Diseases




Stem Cells Show Potential for Treatment of Some Lung Diseases


Researchers in Korea have transplanted mesenchymal stem cells from umbilical cord blood into the respiratory system of animals whose lungs were damaged. They found that the cells started to repair part of the damaged lungs. They were assimilated into the organ and differentiated into lung tissue. The story is reported in the Korea Times. No significant further details, and one of the researchers "cautioned that it was too early to say whether the animal tests are conclusive or if human tests would have the same results."


This is obviously promising, but still a long way from human therapies. I presume that some kinds of lung injury/disease would be more amenable to this kind of treatment than others.


Skin Cells Difficult to Grow from Embryonic Stem Cells


Skin Cells Difficult to Grow from Embryonic Stem Cells


According to an article in Scientific American, researchers at Harvard have had several struggles in attempts to get embryonic stem cells to differentiate into skin cells (keratinocytes) in culture. Most cells did not differentiate, and those that did grew poorly. When the researchers added genetic material from the human papillomavirus (the virus responsible for cervical cancer), the stem cells grew well but still did not differentiate in the way that normal skin cells do.


The article suggests that embryonic stem cell research is still highly challenging. After having read some of the other recent studies that have come out, though, I find myself curious about the culture mediums that were used and what the application of the right growth factors would do. It's starting to seem like a lot of factors influence stem cell differentiation, and a failure in one place does not mean a failure in all. The only way to find out will be to keep trying.





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