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April 23, 2007, 5:17 PM CT

Protecting Nerve Fibers In MS

Protecting Nerve Fibers In MS
Oregon Health & Science University neuroresearchers are eyeing a protein as a potential therapeutic target for multiple sclerosis because de-activating it protects nerve fibers from damage.

OHSU researchers, working with colleagues at the Portland Veterans Affairs Medical Center and the University of Padova in Italy, have shown that genetically inactivating a protein called cyclophilin D can protect nerve fibers in a mouse model of multiple sclerosis. Cyclophin D is a key regulator of molecular processes in the nerve cell's powerhouse, the mitochondrion, and can participate in nerve fiber death. Inactivating cyclophilin D strengthens the mitochondrion, helping to protect nerve fibers from injury. The findings are published recently in Proceedings of the National Academy of Sciences.

"We're extremely excited," said Michael Forte, Ph.D., senior scientist at the Vollum Institute at OHSU and the study's lead author. "While we can't genetically inactivate cyclophilin D in people, there are drugs out there that can block the protein. Our research predicts that drugs that block cyclophilin D should protect nerve fibers from damage in MS".

Such a drug would be the first treatment specifically for secondary-progressive MS, one of the more debilitating forms of MS involving an initial period of relapsing and remitting, followed by a steady worsening of symptoms. It affects half of the estimated 2 million people with MS.........

Posted by: Scott      Read more         Source


April 21, 2007, 6:49 AM CT

Brain networks strengthened by ion channels

Brain networks strengthened by ion channels
Yale School of Medicine and University of Crete School of Medicine scientists report in Cell April 20 the first evidence of a molecular mechanism that dynamically alters the strength of higher brain network connections.

This discovery may help the development of drug therapies for the cognitive deficits of normal aging, and for cognitive changes in schizophrenia, bipolar disorder, or attention deficit hyperactivity disorder (ADHD).

"Our data reveal how the brains arousal systems influence the cognitive networks that subserve working memorywhich plays a key role in abstract thinking, planning, and organizing, as well as suppressing attention to distracting stimuli," said Amy Arnsten, lead author and neurobiology professor at Yale.

The brains prefrontal cortex (PFC) normally is responsible for so-called executive functions. The ability of the PFC to maintain such memory-based functions declines with normal aging, is weakened in people with ADHD, and is severely disrupted in disorders such as schizophrenia and bipolar disorder.

The current study observed that brain cells in PFC contain ion channels called hyperpolarization-activated cyclic nucleotide-gated channels (HCN), that reside on dendritic spines, the tiny protrusions on neurons that are specialized for receiving information. These channels can open when they are exposed to cAMP (cyclic adenosine monophosphate). When open, the information can no longer flow into the cell, and thus the network is effectively disconnected. Arnsten said inhibiting cAMP closes the channels and allows the network to reconnect.........

Posted by: Daniel      Read more         Source


April 19, 2007, 7:42 PM CT

How Viruses Invade The Brain

How Viruses Invade The Brain
A molecule thought crucial to ferrying the deadly rabies virus into the brain, where it eventually kills, apparently isnt. The surprising finding, say scientists at Jefferson Medical College in Philadelphia, may change the way researchers think about how central nervous system-attacking viruses such as herpes viruses invade the brain and cause disease.

As per Matthias Schnell, Ph.D., professor of microbiology and immunology at Jefferson Medical College of Thomas Jefferson University, viruses such as rabies must be actively transported to the brain and central nervous system. The LC8 protein was thought to tether viruses to the cellular transport machinery in order to get there.

But Dr. Schnell and his co-workers observed that this protein complex is instead a "transcription factor" that plays a role in virus reproduction. "We believe that this finding has implications not only for rabies but a number of viruses that previously were thought to use this complex for transport, such as herpes viruses," he says. They report their results online this week in the journal Proceedings of the National Academy of Sciences.

To understand the role of LC8 in rabies disease in the brain, the team compared a rabies virus strain with the LC8 "binding domain" (where the rabies virus and LC8 protein interact) to a virus lacking it. They showed that in mice that were infected with rabies without the LC8 binding domain, the virus was still able to infect the brain, but did not cause disease. The virus ability to reproduce was greatly diminished.........

Posted by: Daniel      Read more         Source


April 17, 2007, 11:13 PM CT

Stem cells decrease ischemic injury

Stem cells decrease ischemic injury
This is the impressive result of a study carried out by a group of scientists coordinated by Dr. Maria Grazia De Simoni of the Mario Negri Institute in Milan, Italy in cooperation with the Istituto Neurologico Besta (Milan) and the University of Lausanne. The study appears in the April 18th issue of the international, peer-evaluated, open-access online journal of the Public Library of Science, PLoS ONE.

Stroke is the first cause of permanent invalidity and the third cause of death in industrialized countries.

Despite the recent advancements in the management of ischemic patients (early diagnosis, thrombolysis, stroke units and rehabilitation centers), stroke still represents a major and unresolved medical issue.

"Stroke causes the death of a number of nervous cells that, in theory, could be substituted by stem cells. A few studies have shown that these cells can be effective, eventhough various issues about their use and the mechanisms of their protective action remained unsolved," says Maria Grazia De Simoni.

"Our research has underlined a possible mechanism of action. Once introduced in the area of the brain hit by a stroke, stem cells induce the development of a protective effect in this same area," explains De Simoni. "Therefore, it is not necessary, as proposed in past studies, for stem cells to turn into neurons in order to protect the brain from ischemic injury and restore brain functions. Their presence in brain tissue is sufficient to induce a protective reaction".........

Posted by: Daniel      Read more         Source


April 17, 2007, 10:58 PM CT

Insights Into Multiple Sclerosis

Insights Into Multiple Sclerosis Myelin Sheath and Astroglial Filaments
Scientists have developed a way to use three types of microscopic imaging techniques simultaneously to analyze living tissue and learn more about the molecular mechanisms of multiple sclerosis, information that could help lead to earlier detection and new therapys.

The combined imaging method is enabling the scientists to study how multiple sclerosis causes an overproduction of "astroglial filaments," which form bundles between critical nerve fibers and interfere with proper spinal cord functioning. The technique also promises to yield new information about how the disease degrades the myelin sheath, which insulates nerve fibers and enables them to properly conduct impulses in the spinal cord, brain and in the "peripheral nervous system" throughout the body, said Ji-Xin Cheng, an assistant professor in Purdue University's Weldon School of Biomedical Engineering and Department of Chemistry.

The three imaging techniques - called sum frequency generation, two-photon-excitation fluorescence and coherent anti-Stokes Raman scattering - ordinarily are used alone. Purdue scientists have developed a way to combine all three methods in the same platform, promising to reveal new details about the spinal cord and myelin sheath, Cheng said.

"Combining these three methods allows us to conduct more specific and precise molecular analyses," he said. "Ultimately, this work paves the way toward studying the degradation of the myelin sheath as a result of multiple sclerosis and analyzing living tissue to study the mechanisms of disease".........

Posted by: Daniel      Read more         Source


April 17, 2007, 10:56 PM CT

Treating Alzheimer's Disease

Treating Alzheimer's Disease Arun Ghosh, at right, and Xiaoming Xu
molecule designed by a Purdue University researcher could lead to the first drug therapy for Alzheimer's disease.

"There are a number of people suffering, and no effective therapy is available to them," said Arun Ghosh, the Purdue professor who designed the molecule. "There is an urgent need for a drug to treat this devastating disease, and the scientific community has been working on this problem for a number of years".

The National Institute on Aging estimates that as a number of as 4.5 million Americans suffer from Alzheimer's disease, which leads to dementia by affecting parts of the brain that control thought, memory and language.

The new molecule prevents the first step in a chain of events that leads to amyloid plaque formation in the brain. The material at various stages of plaque formation is made up of fibrous clumps of toxic proteins that cause the devastating symptoms of Alzheimer's disease, said Ghosh, who has a dual appointment in the chemistry and medicinal chemistry and molecular pharmacology departments.

"Interdisciplinary research and the tools available today allowed us to build a molecule that is both highly potent and highly selective, meaning it does not affect other enzymes important to brain function," he said.

Jordan Tang, head of the Protein Studies Research Program at the Oklahoma Medical Research Foundation, is one of the discoverers of the critical enzyme and target for intervention, Ghosh said.........

Posted by: Daniel      Read more         Source


April 17, 2007, 5:05 AM CT

Gene Crucial For Nerve Cell Insulation

Gene Crucial For Nerve Cell Insulation
Scientists funded by the National Institutes of Health have discovered how a defect in a single master gene disrupts the process by which several genes interact to create myelin, a fatty coating that covers nerve cells and increases the speed and reliability of their electrical signals.

The discovery has implications for understanding disorders of myelin production. These disorders can affect the peripheral nervous systemthe nerves outside the brain and spine. These disorders are known collectively according toipheral neuropathies. Peripheral neuropathies can result in numbness, weakness, pain, and impaired movement. They include one of the most common genetically genetic disorders, Charcot-Marie-Tooth disease, which causes progressive muscle weakening.

The myelin sheath that surrounds a nerve cell is analogous to the insulating material that coats an electrical cord or wire, keeping nerve impulses from dissipating, allowing them to travel farther and faster along the length of the nerve cell.

The scientists discovered how a defect in just one copy of the gene, known as early growth response gene 2 (EGR2) affects the normal copy of the gene as well as the functioning of other genes, resulting in peripheral neuropathy.

"The scientists have deciphered a key sequence essential to the assembly of myelin," said Duane Alexander, M.D., Director of the NICHD, the NIH institute that funded the study. "Their discovery will provide important insight into the origins of disorders affecting myelin production".........

Posted by: Daniel      Read more         Source


April 17, 2007, 4:49 AM CT

Change in neuroticism tied to mortality rates

Change in neuroticism tied to mortality rates
While mellowing with age has often been thought to have positive effects, a Purdue University researcher has shown that doing so could also help you live longer.

Dan Mroczek (pronounced Mro-ZAK), an associate professor of child development and family studies at Purdue University, compared neurotic and non-neurotic men over time and tied change in the trait with mortality.

"We observed that neurotic men whose levels dropped over time had a better chance at living longer," Mroczek said. "They seemed to recover from any damage high levels of the trait may have caused. On the flip side, neurotic men whose neuroticism increased over time died much sooner than their peers."

A neurotic personality was defined as a person with the tendency to worry, feel excessive amounts of anxiety or depression and to react to stressful life events more negatively than people with low levels of the trait. Neuroticism levels were measured using a standardized personality test.

Results of the study would be reported in the print edition of the journal Psychological Science in late May. The study is available online at http://www.psychologicalscience.org.

In the study, scientists tracked the change in neuroticism levels of 1,663 aging men over a 12-year period. Using the data gathered in the first analysis, scientists calculated the men's mortality risk over an 18-year period using the average levels and rates of change.........

Posted by: Daniel      Read more         Source


April 13, 2007, 4:57 PM CT

Hope For Early Diagnosis Of Alzheimer's

Hope For Early Diagnosis Of Alzheimer's
Research by faculty and staff at Rowan University, Glassboro, N.J.; the University of Pennsylvania School of Medicine; and Drexel University may lead to better diagnosis of early-stage Alzheimers disease.

In a $1.1-million National Institutes of Healths National Institute on Aging study that team members conducted during the last three years, they determined early Alzheimers could be diagnosed with a high rate of accuracy evaluating electroencephalogram (EEG) signals. The study may lead to an earlier diagnosis, and therefore earlier therapy and improved quality of life, for people at the earliest stages of the disease.

As per the Alzheimers Association, the condition affects more than 5 million Americans, approximately 1.5 percent of the population. That number is only expected to grow.

Rowan University electrical and computer engineering associate professor Dr. Robi Polikar conducted the research with Dr. Christopher Clark, associate professor of neurology, associate director of the NIH-sponsored Alzheimer's Disease Center at Penn and director of the Penn Memory Center, and with Dr. John Kounios, a Drexel psychology professor.........

Posted by: Daniel      Read more         Source


April 11, 2007, 11:09 PM CT

Stress may help cancer cells resist treatment

Stress may help cancer cells resist treatment
Researchers from Wake Forest University School of Medicine are the first to report that the stress hormone epinephrine causes changes in prostate and breast cancer cells that may make them resistant to cell death.

"These data imply that emotional stress may contribute to the development of cancer and may also reduce the effectiveness of cancer therapys," said George Kulik, D.V.M., Ph.D., an assistant professor of cancer biology and senior researcher on the project.

The study results are reported on-line in the Journal of Biological Chemistry and will appear in a future print issue.

Levels of epinephrine, which is produced by the adrenal glands, are sharply increased in response to stressful situations and can remain continuously elevated during persistent stress and depression, as per prior research. The goal of the current study was to determine whether there is a direct link between stress hormones and changes in cancer cells.

While a link between stress and cancer has been suggested, studies in large groups of people have been mixed.

"Population studies have had contradictory results," said Kulik. "We asked the question, If stress is associated with cancer, what is the cellular mechanism? There had been no evidence that stress directly changes cancer cells".........

Posted by: Janet      Read more         Source



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Did you know?
The drug Ativan is better than Valium or Dilantin for controlling severe epileptic seizures, according to a new review of studies.Ativan, or lorazepam, and Valium, or diazepam, are both benzodiazepines, the currently preferred class of drugs for treating severe epileptic seizures. Dilantin, or phenytoin, is an anticonvulsant long used for the treatment of epileptic seizures.

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