March 1, 2007, 9:51 PM CT

Insights Into Osteosarcoma In Cats And Dogs

Researchers at the University of Illinois have found that a molecular pathway known to have a role in the progression of bone cancer in humans is also critical to the pathology of skeletal tumors in dogs and cats. Their work could lead to advances in the palliative care of companion animals afflicted with osteosarcoma.

The research team, which included U. of I. pathobiology professor Anne Barger, examined the homeostatic role of an enzyme, receptor activator of nuclear factor kappa-B (known as RANK), and two key modulators of its activity: RANK ligand (RANK-L) and osteoprotegrin (OPG). RANK is one of a family of receptors that regulates bone and immune homeostasis. In health, RANK, RANK-L and OPG together keep the continual process of bone growth and resorption in balance.

Bone tumors presumably derail this homeostatic process, however, by upregulating RANK-L expression. RANK-L binds to RANK, stimulating the production and activation of osteoclasts (bone cells that increase the breakdown of bone tissue).

OPG counter-regulates RANK-L by blocking its ability to bind to RANK.

Eventual therapeutic interventions may make use of OPG or other RANK-L inhibitors to slow the process of bone destruction in skeletal tumors in cats and dogs, Barger said. Although not a cure, this could reduce the pain and other complications associated with bone cancer. Such therapies have proven effective at reducing pathologic bone loss in human bone cancer patients......... Posted by: Sean      Read more         Source

March 1, 2007, 4:40 AM CT

Adolescent Dieting May Predict Weight Gain

Adolescents who go on diets to lose weight may be significantly increasing their odds of gaining weight, say researchers at the University of Minnesota.

The researchers studied results of Project EAT (Eating Among Teens) surveys, conducted in 1999 and 2000, and results of Project EAT II surveys, conducted in 2003 and 2004, to "understand the perplexing finding, that has been reported in several longitudinal studies, whereby dieting predicts greater weight gain over time in adolescents".

According to information provided by more than 2,500 adolescents, dieting predicted increased binge eating and decreased breakfast consumption among girls, "with a nonsignificant trend toward decreased fruit and vegetable intake." Among boys, dieting predicted "increased binge eating, decreased physical activity and a trend toward decreased breakfast consumption. These behaviors were also associated with increases in body mass index," according to the researchers.

The researchers conclude that dieting may lead to weight gain among adolescents in part "via the long-term adoption of behavioral patterns that are counterproductive to weight management"......... Posted by: Sean      Read more         Source

February 27, 2007, 8:22 PM CT

To Differentiate Human Embryonic Stem Cells

Molecular scientists at the Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases (IMM) - which is part of the University of Texas Health Science Center at Houston - have developed a new procedure for the differentiation of human embryonic stem cells, with which they have created the first transplantable source of lung epithelial cells.

The process, created in the laboratory of Rick A. Wetsel, Ph.D., a professor of molecular medicine at the IMM, is described in this week's edition of the Proceedings of the National Academy of Sciences (PNAS). Research scientist Dachun Wang, M.D., is lead author of the article, "A pure population of lung alveolar epithelial type II cells derived from human embryonic stem cells".

"We have developed a reliable molecular procedure which facilitates, via genetic selection, the differentiation of human embryonic stem cells into an essentially pure population of lung epithelial cells," said Wetsel, noting the procedure also can be used to create other types of highly-specialized cells.

Scientists at the IMM used the in vitro method to create lung epithelial cells known as alveolar epithelial type II. The cells were derived from a human embryonic stem cell line approved by the National Institutes of Health (NIH)......... Posted by: Sean      Read more         Source

February 27, 2007, 8:18 PM CT

genetic basis of Type 2 diabetes

Researchers from the Broad Institute of MIT and Harvard, Lund University and Novartis have announced the completion of a genome-wide map of genetic differences in humans and their relationship to Type 2 diabetes and other metabolic disorders.

All results of the analysis are accessible, free of charge, on the Internet to scientists around the world.

The work is the result of a pioneering public-private collaboration known as the Diabetes Genetics Initiative (DGI), which was formed in 2004 and is aimed at deciphering the genetic causes of Type 2 diabetes. Although Type 2 diabetes clearly runs in families, suggesting the importance of inherited factors, its genetic origins remain largely unclear.

"The Human Genome Project, HapMap database and new genomic tools have made it possible for the first time to screen the genome for DNA variations that contribute to common diseases," said principal investigator David Altshuler, the director of the Program in Medical and Population Genetics at the Broad Institute and an associate professor at Massachusetts General Hospital and Harvard Medical School. "Since diabetes and cardiovascular risk factors are influenced by many genes, environment and behavior, these powerful new tools are required to pick up the effect of any one genetic risk factor"......... Posted by: Sean      Read more         Source

February 26, 2007, 8:57 PM CT

How T lymphocytes attack

Our immune system finds it difficult to eliminate tumours effectively. Deciphering the strategies it implements may increase the immune system's effect on tumour cells and thus improve the clinical perspectives for anticancer immune therapy. At the Institut Curie, INSERM and CNRS researchers have used two-photon microscopy to demonstrate, for the first time in vivo and real-time, how T lymphocytes infiltrate a solid tumour in order to fight it.

These "defenders" methodically encircle the enemy positions and "patrol" until they meet a tumour cell, which they have previously learnt to recognise. They then halt to eliminate it, before resuming their rounds. The rapidity of the advance achieved by T lymphocytes is indicative of either the absence of an adversary, or defeat of the immune system in the battlefield.

This scenario was published in The Journal of Experimental Medicine.

How is a tumour destroyed by T lymphocytes? This scenario has recently been visualised by researchers at the Institut Curie. The original images obtained and assembled in twelve video sequences are the result of close collaboration between a specialist in two-photon microscopy, Luc Fetler, an INSERM scientist in the CNRS/Institut Curie "Physical Chemistry Curie" Unit1, and immunologists, notably Alexandre Boissonnas, in the INSERM "Immunity and Cancer" Unit at Institut Curie......... Posted by: Sean      Read more         Source

February 26, 2007, 7:13 PM CT

Atomic Movements And Pharmaceuticals

Chemists at the University of Liverpool have designed a unique structure to capture the movement of atoms which may impact on future designs of pharmaceuticals.

The research, funded by the Engineering and Physical Sciences Research Council (EPSRC), will further understanding of how to control chemical reactions and will influence improvements in a range of important processes from the design of biopharmaceuticals to the engineering of new catalysts, enabling scientists, for example, to develop products in more environmentally friendly ways.

The Liverpool team created a porous crystal which has 'walls' of atoms and cavities which act as containers for molecules. They used this crystal to accommodate a set of molecules as they took part in a chemical reaction similar to reactions by enzymes and proteins to regulate and keep alive living systems.

The crystal was put into a powerful X-ray diffraction machine at Daresbury laboratory, Warrington. This allowed researchers to pinpoint precisely the positions of individual atoms, providing snapshots of their movement. Because the reaction was carried out within the cavities of the crystal, the team was able to locate the positions of the atoms both before and after the reaction. This is the first time that the positions of atoms both at the beginning and the end of a chemical process have been seen......... Posted by: Sarah      Read more         Source

February 26, 2007, 6:29 PM CT

Avoiding Carpal Tunnel Syndrome

In work involving the hands, whether using a computer or a hammer, the wrist is a vulnerable spot. Repeated or sustained bending and flexing can lead to carpal tunnel syndrome (CTS).

A group of human factors/ergonomics (HF/E) researchers from the University of California at San Francisco and McMaster University in Ontario, Canada, have conducted the first study that systematically identifies how one contributor to CTS carpal tunnel pressure can be examined in detail to establish limits on how much a wrist can be flexed before nerve damage sets in. The researchers believe their findings could be used to create simple guidelines to help workers avoid wrist postures that are likely to cause nerve trauma. The findings from their study appear in a paper in the recent issue of Human Factors: The Journal of the Human Factors and Ergonomics Society.

The research team studied the pressure that is placed on the nerve in the carpal tunnel in various wrist postures in 37 healthy men and women between the ages of 22 and 50. Wrist postures that are not neutral (that is, bent or flexed) cause increased pressure on the nerve. The researchers concluded that when sustained pressure on the carpal tunnel reaches 30 mmHG, injury is likely to occur.

In order to keep pressure below 30 mmHG, it is recommended that sustained wrist extension (bending the hand back) should not exceed 32.7 degrees, wrist flexion (bending the wrist toward the palm) should not exceed 48.6 degrees, ulnar deviation (sideways toward the small finger) should not exceed 14.5 degrees, and radial deviation (sideways toward the thumb) should not exceed 21.8 degrees......... Posted by: Sean      Read more         Source

February 21, 2007, 9:03 PM CT

Reduced Brain Growth In Alcoholics

The brains of alcohol-dependent individuals are affected not only by their own heavy drinking, but also by genetic or environmental factors associated with their parents drinking, according to a new study by researchers at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH). Researchers found reduced brain growth among alcohol-dependent individuals with a family history of alcoholism or heavy drinking compared to those with no such family history. Their report has been published online in Biological Psychiatry at http://www.sciencedirect.com/science/journal/00063223 as an article in press.

"This is interesting new information about how biological and environmental factors might interact to affect children of alcoholics," notes George Kunos M.D., Ph.D., Scientific Director, Division of Intramural Clinical and Biological Research, NIAAA.

Many studies have shown that alcohol-dependent men and women have smaller brain volumes than non-alcohol-dependent individuals. It is widely believed that this is due to the toxic effects of ethanol, which causes the alcoholics brain to shrink with aging to a greater extent than the non-alcoholics.

"Our study is the first to demonstrate that brain size among alcohol-dependent individuals with a family history of alcoholism is reduced even before the onset of alcohol dependence," explains first author Jodi Gilman, B.S., a NIAAA research fellow and Ph.D. candidate at Brown University working with senior author Daniel Hommer, M.D., of the NIAAA Laboratory of Clinical and Translational Studies (LCTS) and co-author James Bjork, Ph.D., also of the NIAAA/LCTS......... Posted by: Sean      Read more         Source

February 20, 2007, 7:48 PM CT

Test Identifies Lymphoma Patients Likely to Respond

Researchers at the Albert Einstein College of Medicine of Yeshiva University have discovered a genetic signature identifying cases of lymphoma that are uniquely susceptible to a newly developed molecular targeted therapy. As a result, physicians organizing clinical trials of the new therapy will be able to enroll patients who'll be most likely to benefit from it.

The research was led by Dr. Ari Melnick, assistant professor of developmental & molecular biology and medicine at Einstein, who also developed the new lymphoma therapy. The study appears in the February 20 issue of the Proceedings of the National Academy of Sciences.

Each year more than 60,000 Americans are diagnosed with B cell lymphomas-tumors of cells of the immune system that include Hodgkin's and non-Hodgkin's lymphomas. B cells are the immune-system cells that make antibodies. Genetic aberrations can cause B cells to multiply uncontrollably, causing B cell lymphomas.

Dr. Melnick's study focused on a gene called BCL6. The protein it codes for is a transcriptional repressor, which means that it can shut off the functioning of genes in B cells and other cells of the immune system and prevent them from being expressed. The BCL6 protein is normally produced only during a specific stage of B cell development and is never made again. But deregulation of BCL6 can cause the protein to be produced when it shouldn't be. The unwelcome presence of the BCL6 protein blocks the expression of important genes that normally protect cells from becoming cancerous. As a result, malignant B-cell lymphomas occur......... Posted by: Sean      Read more         Source

February 13, 2007, 9:48 PM CT

Vastly Improved Medical Imaging

Magnetic resonance imaging, or MRI, has revolutionized health care, providing doctors with a highly accurate, non-invasive tool for diagnosing cancer, injuries and other maladies within the human body. Now, a Florida State University researcher has collaborated in a research project that could lead to ways of producing even sharper medical images.

Naresh Dalal, the Dirac Professor of Chemistry and Biochemistry at FSU, recently conducted experiments with other scientists from FSU, the University of Colorado and the National Institute of Standards and Technology that uncovered unique properties in a molecular magnet properties that could significantly increase the resolution of MRIs. Their paper, "Efficacy of the Single-Molecule Magnet Fe8 for Magnetic Resonance Imaging Contrast Agent Over a Broad Range of Concentration," was reported in the current issue of Polyhedron, a rigorously peer-evaluated science journal.

"There are continual efforts to enhance the level of image clarity found in today's MRI devices," Dalal said. "MRIs utilize injectable dyes, but those in current use, while easy to manufacture, offer a relatively low contrast. Our experiments show that a class of materials known as single-molecule magnets might produce greater contrast in medical imaging, meaning MRIs would be much more accurate."Working at FSU and the National High Magnetic Field Laboratory, Dalal and another FSU researcher, chemistry graduate teaching assistant Vasanth Ramachandran, were able to synthesize a substance known as Fe8 that is one of the strongest magnets known......... Posted by: Sean      Read more         Source