July 29, 2006, 8:49 PM CT

Genetic Model For Parkinson's Disease

In the mouse model generated by the research team, a gene called TFAM is automatically deleted from the genome in dopamine nerve cells only. Without TFAM, mitochondria cannot function normally. The so called respiratory chain is compromised and energy production decreases severely in the dopamine cells.

The new mice are born healthy from healthy but genetically modified parents and will develop spontaneous disease. Prior studies in the field have been based on scientists delivering neurotoxic substances to kill the dopamine neurons. In the new mice, however, mice develop disease slowly in adulthood, like humans with Parkinson's disease, which may facilitate research aimed at finding novel medical therapys and other therapies.

"We see that the dopamine producing nerve cells in the brain stem slowly degenerate", says Dr. Nils-Gran Larsson. "In the microscope we can see.

that the mitochondria are swollen and that aggregates of a protein, probably alpha-synuclein starts to accumulate in the nerve cell bodies. Inclusions of alpha-synuclein-rich so called Lewy bodies is typical for the human disease".

The causes of Parkinson's disease have long remained a mystery. Genes and environment are both implicated, but recently there has been an increased focus on the roles of genetic factors. It has been observed that mutations in many genes can lead directly to disease, while other mutations may be susceptibility factors, so that carriers have an increased risk of becoming ill. A common denominator for some of the implicated genes is their suggested role for the normal functioning of mitochondria.........

Posted by: Daniel      Permalink         Source

July 29, 2006, 8:13 PM CT

meditation and cognitive impairment

Scientists at the University of Pennsylvania School of Medicine are examining the effectiveness of meditation on early cognitive impairment. Once this new study is completed, the results could help answer lingering questions over whether or not stress-reducing techniques and mind exercises can lessen or even prevent cognitive decline. This is the first study at Penn's new "Center for Spirituality and the Mind," which evolved from work initiated in Penn's Department of Radiology to embrace and encourage scientists from the fields of medicine, pastoral care, religious studies, social work, nursing, and bioethics to expand our knowledge of how spirituality may affect the human brain.

"We'll be looking at patients with mild cognitive impairment or symptoms of early Alzheimer's disease," explains Andrew Newberg, MD, Associate Professor of Radiology, Psychiatry, and Religious Studies, who also directs the Center's investigations and is Principal Investigator of this pilot study. "We'll combine their meditation with brain imaging over a period of time to see if meditation improves cognitive function and is linked to actual change in the brain's activity levels. Specifically, we'll be looking for decreased activity in specific areas of the brain".

The dementia process causes a decreased function of neurons in the brain and can result in problems with memory, visual-spatial tasks, and handling emotional issues. As it worsens in a patient, it can also eventually lead to the need for round-the-clock care.........

Posted by: JoAnn      Permalink         Source

July 28, 2006, 10:41 PM CT

Radiation Cocktail For Breast Cancer

A carefully determined mixture of electron and x-ray beams precisely treated breast tumors while significantly reducing collateral skin damage in 78 patients, scientists will report on August 1 at the annual meeting of the American Association of Physicists in Medicine in Orlando. The key to choosing the right mixture of beams, as well as their individual properties, was a sophisticated computer approach developed by medical physicists Jinsheng Li, Ph.D. (Jinsheng.Li@fccc.edu) and Chang-Ming Ma, Ph.D. of Fox Chase Cancer Center in Philadelphia.

In treating shallow tumors such as those that occur in the breast, physicians have been turning to mixed-beam radiation treatment (MBRT), which employs separate beams of electrons and photons (x-rays). The two types of radiation complement one another, as electrons generally travel to shallow depths while the x-rays can penetrate to deeper parts of the tumor as needed.

However, each beam interacts in complex ways with its environment, making their exact path to the tumor region hard to predict. Nonetheless, physicists can calculate the probability for a given beam to follow a desired trajectory.

Therefore, Li and Ma use computers to simulate billions of trips of each beam to the unique landscape of each tumor. Gathering the statistics from these billions of trials, they determine the best beam properties and mixtures.........

Posted by: Janet      Permalink         Source

July 28, 2006, 10:34 PM CT

Pigeons provide clues

Through studying pigeons with genetic heart disease, scientists at Wake Forest University School of Medicine have discovered a clue about why some patients' heart vessels are prone to close back up after angioplasty.

"We identified a regulator of genes that controls the growth of artery smooth muscle cells," said William Wagner, Ph.D., senior researcher. "Learning to modulate the uncontrolled growth of these cells could potentially solve the problem of vessels re-closing after angioplasty".

The work is published in the recent issue of Experimental and Molecular Pathology.

Angioplasty uses a balloon-like device to crush the material blocking an artery. But, within three to six months, even if a stent is placed in the artery to keep it open, the vessel becomes re-blocked in about 25 percent to 30 percent of patients. This process, known as restenosis, has been described as "over exuberant" tissue healing and involves the smooth muscle cells. It is not known why this happens in some people and not in others, but a number of researchers think that genes are to blame, Wagner said.

The scientists sought to find the answer in two breeds of pigeons one that is genetically susceptible to heart attacks and heart vessel disease (white carneau) and one (show racer) that is resistant. A major difference between the two breeds is that smooth muscle cells from the heart vessels of white carneau pigeons are prone to uncontrolled growth.........

Posted by: Daniel      Permalink         Source

July 28, 2006, 10:19 PM CT

gene therapy for hereditary heart conditions

A new way of delivering corrective genes with a single injection into a vein holds promise for long-lasting therapys of hereditary diseases of the heart, University of Florida scientists report.

UF scientists used the approach to successfully reverse symptoms in mice with a form of muscular dystrophy that damages the heart. They also tested the virus-based delivery method in monkeys and found genes were readily absorbed by heart muscle cells, and the effect persisted for months.

The findings, published July 27 in the online edition of Circulation Research, pave the way for studies in humans that could begin as soon as early next year for patients with Pompe disease, a rare form of muscular dystrophy that is commonly fatal in the first year of life.

"Nine years ago we knew we could get long-term gene expression in the heart but it was with direct injection into the heart muscle and it was inefficient," said UF pediatric cardiologist Barry J. Byrne, M.D., Ph.D., the paper's senior author and director of the Powell Gene Therapy Center. "The difference here is that we can deliver a much lower dose of the vector into a vein like any other drug, and the corrective gene collects in the heart".

Researchers say gene treatment looks increasingly feasible for the therapy of cardiovascular conditions associated with faulty genes or congenital metabolic diseases, including atherosclerosis, stroke, muscular dystrophy and an enlargement of the heart muscle known as dilated cardiomyopathy.........

Posted by: Daniel      Permalink         Source

July 28, 2006, 10:03 PM CT

Peaks And Troughs Of Dengue Epidemics

Researchers have long known that epidemics of dengue fever wax and wane over a period of several years, but they've never been quite sure why. With the incidence and range of the potentially deadly mosquito-borne illness increasing, understanding the factors that influence these epidemics has never been more important.

A new study by scientists at the University of Georgia suggests that a brief period of cross-immunity conferred by any one of the four viral strains, or serotypes, that cause dengue explains the timing of epidemics.

"We observed that since about the mid 1980s, there's been a sequential replacement of the dominant serotype," said lead author Helen Wearing, a post-doctoral researcher at the UGA Institute of Ecology. "So, for example, one year serotype three is 60 percent of the cases and the next year serotype two is dominant and so on. Epidemics of individual serotypes recur every eight to 10 years, but, at the same time, if you look at all the data together, you see about an average three-year cycle with some seasonal component to it".

In addition to helping resolve a long-standing debate in public health, the study, published this week in the early online edition of the journal Proceedings of the National Academy of Sciences, gives scientists a framework that can be used to create models that predict dengue outbreaks in both space and time.........

Posted by: Mark      Permalink         Source

July 28, 2006, 9:35 PM CT

Brain In Action

For the first time, researchers have been able to watch neurons within the brain of a living animal change in response to experience.

Thanks to a new imaging system, scientists at the Picower Institute for Learning and Memory have gotten an unprecedented look into how genes shape the brain in response to the environment. Their work is published in the July 28 issue of Cell.

"This work represents a technological breakthrough," said first author Kuan Hong Wang, a research scientist at the Picower Institute who will launch his own laboratory at the National Institute of Mental Health in the fall. "This is the first study that demonstrates the ability to directly visualize the molecular activity of individual neurons in the brain of live animals at a single-cell resolution, and to observe the changes in the activity in the same neurons in response to the changes of the environment on a daily basis for a week."

This advance, coupled with other brain disease models, could "offer unparalleled advantages in understanding pathological processes in real time, leading to potential new drugs and therapys for a host of neurological diseases and mental disorders," said Nobel laureate Susumu Tonegawa, a co-author of the study.

An unexpected finding.

Tonegawa, director of the Picower Institute and the Picower Professor of Biology and Neuroscience at MIT, Wang and his colleagues observed that visual experience induces a protein that works as a molecular "filter" to enhance the overall selectivity of the brain's responses to visual stimuli.........

Posted by: Daniel      Permalink         Source

July 28, 2006, 9:30 PM CT

Nanotechnology And Atherosclerosis

In laboratory tests, one very low dose of a drug was enough to show an effect on notoriously tenacious artery-clogging plaques. What kind of drug is that potent?.

It's not so much the drug itself as how it was delivered. Fumagillin - a drug that can inhibit the growth of new blood vessels that feed atherosclerotic plaques - was sent directly to the base of plaques by microscopically small spheres called nanoparticles developed by scientists at Washington University School of Medicine in St. Louis.

"Previously we reported that we can visualize plaques using our nanoparticle technology, but this is the first time we've demonstrated that the nanoparticles can also deliver a drug to a disease site in a living organism," says Patrick Winter, Ph.D., research assistant professor of medicine. "After a single dose in laboratory rabbits, fumagillin nanoparticles markedly reduced the growth of new blood vessels that feed plaques."

The scientists report their findings in the recent issue of the journal Arteriosclerosis, Thrombosis, and Vascular Biology, and the article is now available on line.

An atherosclerosis plaque results when a buildup of cholesterol, inflammatory cells and fibrous tissue forms inside an artery. If a plaque ruptures, it can block blood flow to the heart or brain, causing heart attack or stroke.........

Posted by: Daniel      Permalink         Source

July 28, 2006, 9:26 PM CT

Steroid Osteoporosis Connection

Scientists are closing in on the solution to a persistent medical puzzle: why do high doses of cortisone, widely prescribed for asthma, rheumatoid arthritis and other inflammatory and autoimmune conditions, weaken bones?

Through studies of mice, researchers at Washington University School of Medicine in St. Louis have now identified osteoclasts, cells that dismantle old bone, as the essential link between osteoporosis and cortisone. As scientists flesh out the molecular-level details of this connection, they may be able to identify targets for therapy to prevent cortisone's damaging side effects on bone.

"High-dose cortisone is the second most common cause of osteoporosis, and we currently have no real treatment for this serious side effect," says senior author Steven L. Teitelbaum, M.D., Messing Professor of Pathology and Immunology. "Given how frequently these drugs are used to treat many different conditions, that's a major clinical problem".

Teitelbaum and colleagues including lead author Hyun-Ju Kim, Ph.D., a postdoctoral fellow, publish their results in the recent issue of the Journal of Clinical Investigation.

Cortisone is a steroid produced naturally by the adrenal gland and synthesized by a number of pharmaceutical companies for clinical use. The drug is also used to treat lupus, multiple sclerosis and chronic obstructive pulmonary disease, and it is prescribed to transplant patients to prevent rejection of transplanted organs.........

Posted by: Scott      Permalink         Source

July 26, 2006, 5:47 PM CT

Treating Severe Psoriasis

NICE's announcement comes as welcome relief to the thousands of UK patients who have exhausted current available therapy options and failed to sustain a long-term benefit. It is a positive sign for patients throughout Europe, whose healthcare systems are influenced by NICE decisions. Leeroy Blake in England was fortunate enough to be offered therapy with a biological treatment, after years of trying every other available psoriasis therapy: "For a number of years, I tried every suitable therapy but nothing seemed to relieve the painful itching. As the itching got worse, I would get more stressed and this only made my condition worse. Following a therapy review with my doctor, I was prescribed a biological treatment and for the first time since developing psoriasis, my skin started to clear and my confidence came back. This therapy might not be suitable for everyone with severe psoriasis, but I believe that it's important that patients at least discuss this option with their doctor".

Latest research has dismissed the preconception that psoriasis is merely a skin complaint, with recent data showing that severe psoriasis can affect a patient's quality of life to a similar extent as other prevalent chronic diseases such as diabetes and even heart diseases.

In addition to the impact on a patient's appearance, up to 30% of patients with psoriasis have been reported to have psoriatic arthritis, which causes pain, stiffness and swelling in and around the joints. Coinciding with its decision on the use of biological therapies in moderate to severe psoriasis, NICE has also given its backing for the NHS to use Enbrel and Remicade (infliximab) to treat patients with severe, active psoriatic arthritis. Professor Robert Moots, Professor of Rheumatology at the University of Liverpool, UK welcomes this guidance commenting, "the NICE guidance is a positive step forward for those patients whose condition is severe enough to warrant therapy with biologic therapies" adding that "the onus is now on NHS trusts to take note of this recent recommendation and ensure that the necessary funding is in place to allow patients access to these much-needed therapies".........

Posted by: George      Permalink         Source