April 11, 2006, 10:52 PM CT

Linking Epstein-barr Virus To Multiple Sclerosis

Scientists from the Harvard School of Public Health, Kaiser Permanente, and a team of collaborators have found further evidence implicating the Epstein-Barr virus (EBV) as a possible contributory cause to multiple sclerosis (MS). The study appears in the advance online edition of the June 2006 issue of Archives of Neurology.

MS is a chronic degenerative disease of the central nervous system. Women are more likely than men to get the disease and it is the most common neurologically disabling disease in young adults. Eventhough genetic predisposition plays an important role in determining susceptibility, past studies have shown that environmental factors are equally important.

EBV is a herpes virus and one of the most common human viruses worldwide. Infection in early childhood is common and commonly asymptomatic. Late age at infection, however, often causes infectious mononucleosis. In the U.S., upwards of 95% of adults are infected with the virus, but free of symptoms. EBV has been associated with some types of cancer and can cause serious complications when the immune system is suppressed, for example, in transplant recipients. There is no effective therapy for EBV.

The study population was made up of more than 100,000 members of the Kaiser Permanente Northern California (KPNC) health plan, who provided blood specimens as part of medical examinations between 1965 and 1974. The KPNC maintained the medical records of all its members, including those who provided specimens, in electronic databases. Between 1995 and 1999, those databases were searched for evidence that would indicate a possible diagnosis of MS.........

Posted by: Daniel      Permalink         Source

April 9, 2006, 7:48 PM CT

Targeting Fat With Laser

Fat may have finally met its match: laser light. Scientists at the Wellman Center for Photomedicine at Massachusetts General Hospital, Harvard Medical School and the Department of Energy's Thomas Jefferson National Accelerator Facility (Jefferson Lab) have shown, for the first time, that a laser can preferentially heat lipid-rich tissues, or fat, in the body without harming the overlying skin. Laser therapies based on the new research could treat a variety of health conditions, including severe acne, atherosclerotic plaque, and unwanted cellulite. The result will be presented at the American Society for Laser Medicine and Surgery (ASLMS) 26th Annual Meeting in Boston, Mass.

In the first part of the study, the scientists used human fat obtained from surgically discarded normal tissue. Based on a fat absorption spectrum, tissue was exposed to a range of wavelengths of infrared laser light (800-2600 nanometers) using the Free-Electron Laser facility at Jefferson Lab. The scientists measured how selected wavelengths heated the fat and compared the result to a similar experiment conducted with pure water. At most infrared wavelengths, water is more efficiently heated by infrared light; however, the scientists found three wavelengths â€" 915, 1210 and 1720 nm â€" where fat was more efficiently heated than water.........

Posted by: JoAnn      Permalink         Source

April 6, 2006, 11:09 PM CT

Nanopore To Revolutionize Genome Sequencing

DNA and Nanopore from Above Credit: Johan Lagerqvist
A team led by physicists at the University of California, San Diego has shown the feasibility of a fast, inexpensive technique to sequence DNA as it passes through tiny pores. The advance brings personalized, genome-based medicine closer to reality.

The paper, reported in the recent issue of the journal Nano Letters, describes a method to sequence a human genome in a matter of hours at a potentially low cost, by measuring the electrical perturbations generated by a single strand of DNA as it passes through a pore more than a thousand times smaller than the diameter of a human hair. Because sequencing a person's genome would take several months and millions of dollars with current DNA sequencing technology, the scientists say that the new method has the potential to usher in a revolution in medicine.

"Current DNA sequencing methods are too slow and expensive for it to be realistic to sequence people's genomes to tailor medical therapys for each individual," said Massimiliano Di Ventra, an associate professor of physics at UCSD who directed the project. "The practical implementation of our approach could make the dream of personalizing medicine as per a person's unique genetic makeup a reality".

The physicists used mathematical calculations and computer modeling of the motions and electrical fluctuations of DNA molecules to determine how to distinguish each of the four different bases (A, G, C, T) that constitute a strand of DNA. They based their calculations on a pore about a nanometer in diameter made from silicon nitride-a material that is easy to work with and usually used in nanostructures-surrounded by two pairs of tiny gold electrodes. The electrodes would record the electrical current perpendicular to the DNA strand as the DNA passed through the pore. Because each DNA base is structurally and chemically different, each base creates its own distinct electronic signature.........

Posted by: Scott      Permalink         Source

April 4, 2006, 0:17 AM CT

Micro Pills To Deliver Drugs On Demand

Scientists have now crafted tiny, hollow capsules out of lipids--water-repellant molecules in the same family as fats and oils--that crumple and collapse when cooled below body temperature. The collapse squeezes out whatever chemicals are inside the miniscule ball in a controlled manner that could one day deliver drugs to the human body or improve cosmetics.

Developed by physicist and NSF (Faculty Early Career Development Program (CAREER) awardee Sahraoui Chaieb and colleagues at the University of Illinois at Urbana-Champaign, the capsules range in size from 10 to 100 micrometers (millionths of a meter) across.

For now, the capsules are in the earliest stages of development and still not ready for medical use, eventhough the scientists are discussing potential applications of the technology with a cosmetics company.

Before the capsules can be used to deliver medicine, the scientists say they must first develop a mechanism to cool the tiny pills without endangering surrounding body tissues.

The research was reported in the Feb. 17 issue of Physical Review Letters.........

Posted by: Scott      Permalink         Source

April 4, 2006, 0:09 AM CT

Supercomputer Maps One Million Atoms of a Complete Virus

For the first time, researchers have visualized the changing atomic structure of a virus by calculating how each of the virus' one million atoms interacted with each other every femtosecond--or one-millionth-of-a-billionth of a second. A better understanding of viral structures and mechanisms may one day allow researchers to design improved strategies to combat viral infections in plants, animals and even humans.

Led by Klaus Schulten at the University of Illinois at Urbana-Champaign, the team tapped the high-performance power of the National Center for Supercomputing Applications (NCSA) processors to accomplish the task. Still, it took about 100 days to generate just 50 nanoseconds of virus activity. Schulten says it would have taken the average desktop computer 35 years to come up with the results.

The simulation revealed key physical properties of satellite tobacco mosaic virus, a very simple, plant-infecting virus. Ultimately, scientists will generate longer simulations from bigger biological entities, but to do so, they need the next generation of supercomputers, the so-called "petascale high-performance computing systems." The National Science Foundation (NSF) is currently devising a national strategy for petascale computing to give scientists and engineers the resources needed to tackle their most computationally intensive research problems.........

Posted by: Scott      Permalink         Source

March 30, 2006, 7:23 AM CT

Vaccine For Alzheimer's Disease?

Doses of DNA-gene-coated gold particles protect mice against a protein implicated in Alzheimer's disease, scientists at UT Southwestern Medical Center have found.

By pressure-injecting the gene responsible for producing the specific protein - called amyloid-beta 42 - the scientists caused the mice to make antibodies and greatly reduce the protein's build-up in the brain. Accumulation of amyloid-beta 42 in humans is a hallmark of Alzheimer's disease.

"The whole point of the study is to determine whether the antibody is therapeutically effective as a means to inhibit the formation of amyloid-beta storage in the brain, and it is," said Dr. Roger Rosenberg, the study's senior author and director of the Alzheimer's Disease Center at UT Southwestern.

The gene injection avoids a serious side-effect that caused the cancellation of a prior multi-center human trial with amyloid-beta 42, scientists said. UT Southwestern did not participate in that trial. In that earlier study, people received injections of the protein itself and some developed dangerous brain inflammation.

The new study is available online and appears in an upcoming issue of the Journal of the Neurological Sciences.

The scientists used mutant mice with two defective human genes associated with Alzheimer's, genes that produce amyloid-beta 42. "By seven months, the mice are storing abundant amounts of amyloid-beta 42," said Dr. Rosenberg, who holds the Abe (Brunky), Morris and William Zale Distinguished Chair in Neurology.........

Posted by: Daniel      Permalink         Source

March 20, 2006, 7:48 PM CT

Researchers Find Fat Gene

Rutgers scientists have identified a gene - and the molecular function of its protein product - that provides an important clue to further understanding obesity and may point the way to new drugs to control fat metabolism.

The researchers found that the human protein known as lipin is a key fat-regulating enzyme. "Lipin activity may be an important pharmaceutical target for the control of body fat in humans, treating conditions that range from obesity to the loss of fat beneath the skin, as seen in HIV patients, " said George M. Carman, a professor in Rutgers' department of food science.

In a paper published online by the Journal of Biological Chemistry (print version, April 7), Carman and his research team at Rutgers' Cook College describe their scientific detective work, moving from clue to clue in a series of logical connections to reach their discoveries.

Prior studies with mice showed that a lack of lipin causes a loss of body fat, whereas an excess of lipin promotes extra body fat. So scientists knew that lipin was involved in fat metabolism; they just didn't know how.

The Carman team's first revelation came with the discovery that lipin is an enzyme (phosphatidic acid phosphatase or PAP), a protein catalyst that is mandatory for the formation of fats - triglycerides, specifically.........

Posted by: JoAnn      Permalink         Source

March 16, 2006, 10:51 PM CT

MIT Researchers Restore Vision In Rodents

Rodents blinded by a severed tract in their brains' visual system had their sight partially restored within weeks, thanks to a tiny biodegradable scaffold invented by MIT bioengineers and neuroscientists.

This technique, which involves giving brain cells an internal matrix on which to regrow, just as ivy grows on a trellis, may one day help patients with traumatic brain injuries, spinal cord injuries and stroke.

The study, which will appear in the online early edition of the Proceedings of the National Academy of Sciences (PNAS) the week of March 13-17, is the first that uses nanotechnology to repair and heal the brain and restore function of a damaged brain region.

"If we can reconnect parts of the brain that were disconnected by a stroke, then we may be able to restore speech to an individual who is able to understand what is said but has lost the ability to speak," said co-author Rutledge G. Ellis-Behnke, research scientist in the MIT Department of Brain and Cognitive Sciences. "This is not about restoring 100 percent of damaged brain cells, but 20 percent or even less may be enough to restore function, and that is our goal".

Spinal cord injuries, serious stroke and severe traumatic brain injuries affect more than 5 million Americans at a total cost of $65 billion a year in therapy.........

Posted by: Daniel      Permalink         Source

March 15, 2006, 6:47 AM CT

Halting Alzheimer's By Blocking An Enzyme

Oregon Health & Science University is participating in a national study of a drug that may prevent Alzheimer's disease by blocking an enzyme that produces plaques believed to trigger the disorder.

OHSU is one of six sites around the country taking part in a double-blind, placebo-controlled study of the agent known as LY450139, a gamma secretase inhibitor manufactured by Indianapolis-based Eli Lilly and Co. Other study sites are in Indianapolis, St. Louis, Philadelphia, Seattle, and La Jolla, Calif. Lilly is funding the study.

Gamma secretase is an enzyme that produces beta-amyloid by snipping a fragment of the protein from a larger protein that extends across the plasma membrane of the cell. The beta-amyloid fragments clump together to form dense, insoluble plaques inside the hippocampus, a curved, elongated ridge deep in the brain that controls learning and memory, and the cerebral cortex, the surface layer of gray matter of the cerebrum where sensory and motor information is coordinated.

The gamma secretase enzyme is made up of a complex of four proteins, and LY450139 is thought to de-activate it by binding within the complex, eventhough the exact location is still being studied.

"There is a theory that beta-amyloid produces Alzheimer's disease, so if you stop the amyloid, you stop the disease," said Joseph Quinn, M.D., associate professor of neurology, and cell and developmental biology, OHSU School of Medicine and the Portland Veterans Affairs Medical Center. He also is an investigator at OHSU's Layton Aging & Alzheimer's Disease Center.........

Posted by: Daniel      Permalink         Source

March 15, 2006, 6:25 AM CT

Jalapenos To Fight Prostate Cancer

Capsaicin, the stuff that turns up the heat in jalapeños, not only causes the tongue to burn, it also drives prostate cancer cells to kill themselves, as per studies reported in the March 15 issue of Cancer Research.

As per a team of scientists from the Samuel Oschin Comprehensive Cancer Institute at Cedars-Sinai Medical Center, in collaboration with colleagues from UCLA, the pepper component caused human prostate cancer cells to undergo programmed cell death or apoptosis.

Capsaicin induced approximately 80 percent of prostate cancer cells growing in mice to follow the molecular pathways leading to apoptosis. Prostate cancer tumors treated with capsaicin were about one-fifth the size of tumors in non-treated mice.

"Capsaicin had a profound anti-proliferative effect on human prostate cancer cells in culture," said Soren Lehmann, M.D., Ph.D., visiting scientist at the Cedars-Sinai Medical Center and the UCLA School of Medicine. "It also dramatically slowed the development of prostate tumors formed by those human cell lines grown in mouse models."

Lehmann estimated that the dose of pepper extract fed orally to the mice was equivalent to giving 400 milligrams of capsaicin three times a week to a 200 pound man, roughly equivalent to between three and eight fresh habañera peppers - depending on the pepper's capsaicin content. Habañeras are the highest rated pepper for capsaicin content as per the Scoville heat index. Habañero peppers, which are native to the Yucatan, typically contain up to 300,000 Scoville units. The more popular Jalapeño variety from Oaxaca, Mexico, and the southwest United States, contains 2,500 to 5,000 Scoville units.........

Posted by: Mark      Permalink         Source