November 12, 2008, 10:18 PM CT
In the war against diseases, nerve cells need their armor
In a new study, scientists at the Montreal Neurological Institute (MNI), McGill University, and the Universit de Montral have discovered an essential mechanism for the maintenance of the normal structure of myelin, the protective covering that insulates and supports nerve cells (neurons). Up until now, very little was known about myelin maintenance. This new information provides vital insight into diseases such as Multiple Sclerosis (MS) and other progressive demyelinating diseases in which myelin is destroyed, causing irreversible damage and disrupting the nerve cells' ability to transmit messages. The research, published recently in the Journal of Neuroscience
, is the first to identify a role for the protein netrin-1, previously characterized only in the developing nervous system, with this critical function in the adult nervous system. This research was funded by the MS Society of Canada and the Canadian Institutes of Health Research.
Netrin-1, a protein deriving its name from the ancient Indian language, Sanskrit, word for 'one who guides,' is known to guide and direct nerve cell axons to their targets. In the molecular biological studies conducted by the team, they observed that blocking the function of netrin-1 and one of its receptors in adult neural tissue causes the disruption of myelin. "We've known for just over 10 years that netrin is essential for normal development of the nervous system, and we also knew that netrin was present in the adult brain, but we didn't know why. It is fascinating that netrin-1 has such a vital role in maintaining the structure of myelin in the adult nervous system," says Dr. Tim Kennedy, a neuroscientist at the MNI and the senior investigator of this study, "continuing to pursue the implications of that are incredibly exciting." "Our mission is to find a cure as quickly as possible and enhance quality of life," says Karen Lee, assistant vice-president of research programs for the MS Society of Canada. "We are pleased to be involved in funding work that supports our mission and feel that this research takes us closer to understanding the players and processes that could aid in remyelination."........
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November 6, 2008, 7:45 PM CT
Achilles' heel in pancreatic cancer
UC Davis Cancer Center scientists have discovered a metabolic deficiency in pancreas cancer cells that can be used to slow the progress of the deadliest of all cancers.
Reported in the recent issue of the International Journal of Cancer
, study results indicate that pancreas cancer cells cannot produce the amino acid arginine, which plays an essential role in cell division, immune function and hormone regulation. By depleting arginine levels in cell cultures and animal models, the team was able to significantly reduce pancreas cancer-cell proliferation.
"There have been few significant advances in 15 years of testing available chemotherapy to treat pancreas cancer," said Richard Bold, chief of surgical oncology at UC Davis and senior author of the study. "The lack of progress is especially frustrating because most patients are diagnosed after the disease has spread to other organs, eliminating surgery as an option. We have to turn back to basic science to come up with new therapys".
Bold explained that average survival time for those diagnosed with pancreas cancer is just four-and-a-half months, eventhough chemotherapy can extend that prognosis up to six months.
"There is a dire need to find new options for these patients. While our findings do not suggest a cure for pancreas cancer, they do promise a possible way to extend the life expectancies of those diagnosed with it," Bold said.........
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October 31, 2008, 5:15 AM CT
Type-1 diabetes not so much bad genes
Investigators combing the genome in the hope of finding genetic variants responsible for triggering early-onset diabetes may be looking in the wrong place, new research at the Stanford University School of Medicine suggests.
Early-onset diabetes, also known as type-1 diabetes, is an autoimmune disease, caused when the immune system attacks and destroys insulin-producing cells in a person's pancreas.
What triggers that immune response apparently has less to do with having a distinct set of gene variants than how the behavior of genes may differ in people with the disease. That is the finding of a study reported in the recent issue of Clinical Immunology, by Garry Fathman, MD, professor of immunology and rheumatology, and colleagues.
The paper builds upon the knowledge that particular immune-system-related gene variants confer type-1 diabetes susceptibility. A number of people have those genes, but only a fraction actually develop the disease. This has led a number of researchers to conduct exhaustive searches of the genome for other elusive genes that, when defective, may predispose someone to type-1 diabetes. Fathman suggests they may be on the wrong track.
Fathman explained it this way: "Take a pair of identical twins, with one having type-1 diabetes. Eventhough both have precisely the same genes, roughly half the time the other twin doesn't get the disease." The same holds true for other autoimmune diseases such as multiple sclerosis and rheumatoid arthritis, he added.........
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October 28, 2008, 10:28 PM CT
Engineering technique to identify disease-causing genes
Researchers think that complex diseases such as schizophrenia, major depression and cancer are not caused by one, but a multitude of dysfunctional genes. A novel computational biology method developed by a research team led by Ali Abdi, PhD, http://www.njit.edu/news/2008/2008-367.php, associate professor in NJIT's department of electrical and computer engineering, has found a way to uncover the critical genes responsible for disease development.
The research appeared in "Fault Diagnosis Engineering of Digital Circuits Can Identify Vulnerable Molecules in Complex Cellular Pathways," the current cover article of Science Signaling
, a new publication of the American Association for the Advancement of Science, publisher of Science
"We see our research developing a novel technology holding high promises for finding key molecules that contribute to human diseases and for identifying critical targets in drug development," said Abdi. "The key to success was our collaboration among scientists with different backgrounds in engineering and medical sciences".
The researchers analyzed large cellular molecular networks whose dysfunction contributed to the development of certain complex human disorders. Molecules--genes or proteinscommunicate through interconnected pathways via different biochemical interactions, explained Abdi. Through these interactions, molecules propagate regulatory signals. The function of cells in the body is vulnerable to the dysfunction of some molecules within a cell. "In other words," he added, "different diseases may arise from the dysfunction of one or several molecules within an interconnected network system".........
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October 27, 2008, 10:30 PM CT
Brain stimulation improves dexterity
Applying electrical stimulation to the scalp and the underlying motor regions of the brain could make you more skilled at delicate tasks. Research published recently in the open access journal BMC Neuroscience
shows that a non-invasive brain-stimulation technique, transcranial direct current stimulation (tDCS), is able to improve the use of a person's non-dominant hand.
Drs. Gottfried Schlaug and Bradley Vines from Beth Israel Deaconess Medical Center and Harvard Medical School, tested the effects of using tDCS over one side or both sides of the brain on sixteen healthy, right-handed volunteers, as well as testing the effect of simply pretending to carry out the procedure. The volunteers were not aware of which of the three procedures they were receiving. The test involved using the fingers of the left hand to key in a series of numbers displayed on a computer screen.
The results were striking; stimulating the brain over both the right and left motor regions ('dual hemisphere' tDCS) resulted in a 24% improvement in the subjects' scores. This was significantly better than stimulating the brain only over one motor region or using the sham therapy (16% and 12% improvements, respectively).
tDCS involves attaching electrodes to the scalp and passing a weak direct current through the scalp and skull to alter the excitability of the underlying brain tissue. The therapy has two principal modes depending on the direction in which the current runs between the two electrodes. Brain tissue that underlies the positive electrode (anode) becomes more excitable and the reverse is true for brain tissue that underlies the negative electrode (cathode). No relevant negative side effects have been reported with this type of non-invasive brain stimulation. It is not to be confused with electroconvulsive treatment, which uses currents around a thousand times higher.........
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October 27, 2008, 10:28 PM CT
New brain link as cause of schizophrenia
A lack of specific brain receptors has been linked with schizophrenia in new research by researchers at Newcastle University.
In work published recently in the Proceedings of the National Academy of Sciences
, the team has observed that NMDA receptors are essential in modifying brain oscillations electrical wave patterns which are altered in patients with schizophrenia.
They now want to investigate whether optimising the function of the receptors, which are already know to be involved in making memories, could lead to a new way of treating the mental illness.
Schizophrenia is one of the most common serious mental health conditions in the UK and can cause a range of different psychological symptoms, including hallucinations and delusions. One in 100 people will experience at least one episode of acute schizophrenia during their lifetime and it affects men and women equally. While its exact cause is unknown, most experts think that the condition is caused by a combination of genetic and environmental factors.
Dr Mark Cunningham, who led the research at Newcastle University, UK, says: "We have shown that by selectively targeting receptors we can modify the dynamics of the brain. Our hope would be that in the long term this could lead to a method for actually improving brain function, not only for people with schizophrenia but potentially for a number of other brain conditions.........
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October 27, 2008, 5:37 AM CT
High-dose influenza vaccine shows increased immune response
Washington, DC, October 26, 2008 - Sanofi Pasteur, the vaccines division of sanofi-aventis Group, announced recently that an investigational high-dose influenza vaccine demonstrated increased immune responses among adults 65 years of age and older compared with the standard influenza vaccine. The candidate high-dose intramuscular formulation of the influenza vaccine is being developed by sanofi pasteur.
The results were reported today at the 48th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC)/Infectious Diseases Society of America (IDSA) 46th annual meeting.
As per the U.S. Centers for Disease Control and Prevention (CDC), the currently available inactivated influenza vaccine offers public health benefits in reducing influenza-related morbidity and mortality in elderly adults. Study authors explain, however, that as people age, the immune system tends to weaken. Elderly adults become not only more susceptible to infections, but also less responsive to vaccination. When infected with the influenza virus, they are less able to mount an immune response to neutralize the attack. "Development of an influenza vaccine that will provide an improved immune response in elderly adults is important because this population has the highest rates of complications from influenza including hospitalization and death," said Ann R. Falsey, MD Associate Professor of Medicine, University of Rochester School of Medicine, Rochester, NY; Infectious Diseases Unit, Rochester General Hospital. Approximately 90 percent of the 36,000 average annual influenza-associated respiratory and circulatory related deaths occur among adults 65 years of age and older.........
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October 27, 2008, 5:35 AM CT
Credit crunch threatens new medicines
The global financial crisis could seriously delay the discovery and production of a number of new life-saving medicines, warns a major international conference today (Monday).
Investment into research for new drugs - which globally runs into the billions is now seriously at threat as former investors in the drug companies shy away as a result of the economic meltdown.
Professor David Wield, Director of the Economic and Social Research Council's (ESRC) Edinburgh-based Innogen Centre, and chair of the 'Genomics and Society: Reinventing Life?' conference, delivered a stark warning previous to the gathering of over 200 experts at conference in London.
Professor Wield said: "Investing in biotech companies is now seen as risk taking, and will not be for the timid. What will happen to investment in biotech research if finance cannot even be found for relatively everyday expenses which are increasingly becoming more of a struggle?
"Drug discovery depends on long-term finance with high risk of failure and lots of it. Financing of biotechnology companies hit $50bn in 2007. And overall, these biotechs only made profits for the very first time last year, amounting to $1bn on revenues of $59bn".
As per Professor Wield, in addition to the impact on the basic research performed at biotechnology companies, development of medicines by pharmaceutical companies has also been hit by the credit crunch. "Like a number of other sectors, the pharmaceutical industry has had tough times recently there is seemingly no way to speed up and improve the drug discovery pipeline, and heavily increased R&D has not increased the number of new drugs".........
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October 23, 2008, 9:29 PM CT
Self-assembling 'organic wires'
John D. Tovar, assistant professor of chemistry at The Johns Hopkins University.
From pacemakers constructed of materials that so closely mimic human tissues that a patient's body can't discern the difference to devices that bypass injured spinal cords to restore movement to paralyzed limbs, the possibilities presented by organic electronics read like something from a science fiction novel.
Derived from carbon-based compounds (hence the term "organic"), these "soft" electronic materials are valued as lightweight, flexible, easily processed alternatives to "hard" electronics components such as metal wires or silicon semiconductors. And just as the semiconductor industry is actively developing smaller and smaller transistors, so, too, are those involved with organic electronics devising ways to shrink the features of their materials, so they can be better utilized in bioelectronic applications such as those above.
To this end, a team of chemists at The Johns Hopkins University has created water-soluble electronic materials that spontaneously assemble themselves into "wires" much narrower than a human hair. An article about their work was published in a recent issue of the Journal of the American Chemical Society
"What's exciting about our materials is that they are of size and scale that cells can intimately associate with, meaning that they may have built-in potential for biomedical applications," said John D. Tovar, an assistant professor in the Department of Chemistry in the Zanvyl Krieger School of Arts and Sciences. "Can we use these materials to guide electrical current at the nanoscale? Can we use them to regulate cell-to-cell communication as a prelude to re-engineering neural networks or damaged spinal cords? These are the kinds of questions we are looking forward to being able to address and answer in the coming years".........
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October 22, 2008, 10:41 PM CT
New way of inhibiting cell cycle shows promise
Geneva, Switzerland: A new anti-cancer compound that works by blocking a part of the cell's machinery that is crucial for cell division has shown promising results in a phase I clinical trial in patients who have failed to respond to other therapys. Now it is going forward into a phase II clinical trial programme. In addition, the compound will also be tested in combination with other anti-cancer drugs to see whether combined therapies could be even more effective.
Professor Patrick Schffski told the 20th EORTC-NCI-AACR  Symposium on Molecular Targets and Cancer Therapeutics in Geneva today (Wednesday 22 October) that after 50 patients had been given the compound BI 6727 in doses ranging from 12 to 450 mg, two patients with advanced bladder and ovary cancers had shown confirmed partial responses and a further 32% of the patients had stable disease.
"The results so far indicate that BI 6727 is well tolerated by patients, with no serious side-effects detected. We have observed encouraging anti-tumour activity, which we would not necessarily expect to see in a phase I trial, and which warrants investigation in further clinical trials," said Prof Schffski, who is professor of medical oncology and head of the Department of General Medical Oncology at the University Hospitals Leuven (Belgium). .........
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