April 10, 2006, 7:53 PM CT

New Genetic Subtypes Of Myeloma

Researchers at Dana-Farber Cancer Institute and collaborators have identified four distinct genetic subtypes of multiple myeloma, a deadly blood cancer, that have different prognoses and might be treated most effectively with drugs specifically targeted to those subtypes.

A new computational tool based on an algorithm designed to recognize human faces plucked the four distinguishing gene patterns out of a landscape of a number of DNA alterations in the myeloma genome, the scientists report in the recent issue of Cancer Cell.

These results "define new disease subgroups of multiple myeloma that can be correlated with different clinical outcomes," wrote the authors, led by Ronald DePinho, MD, director of Dana-Farber's Center for Applied Cancer Science.

Not only do the findings pave the way for therapys tailored to a patient's specific form of the disease, they also narrow down areas of the chromosomes in myeloma cells likely to contain undiscovered genetic flaws that drive myeloma, and which might turn out to be vulnerable to targeted designer drugs.

Kenneth Anderson, MD, medical director of the Jerome Lipper Multiple Myeloma Center at Dana-Farber and an author of the paper, said the findings "allow us to predict how patients will respond to current therapys based on a genetic analysis of their disease." In addition, the findings "identify a number of new genes implicated in the cause and progression of myeloma, and the product of those genes can be targeted with novel therapies."........

Posted by: Janet      Permalink         Source

April 10, 2006, 7:48 PM CT

Drinking May Cause Higher Death Rates Among Men

Older men who drink as few as two drinks twice a week and also have diseases that could be worsened by alcohol or cause problems with medications taken while drinking alcohol have higher death rates, as compared to men who either drink less or may drink more but don't have such comorbidities.

Examining data from a 1971-74 health survey and a follow-up survey in 1992, the scientists found that older men who drank moderately or heavily and had accompanying comorbidities that could be worsened by alcohol use such as gout or ulcer disease, or who took medications that could interact negatively with alcohol use, such as sedatives or pain medications, had 20 percent higher mortality rates than other drinkers.

The longitudinal study -- the first to examine in a large population the mortality risks inherent in alcohol use and comorbidity -- would be reported in the recent issue of the Journal of the American Geriatrics Society. It is available now online at http://www.blackwell-synergy.com/toc/jgs/0/0.

Prior studies have observed that moderate drinking can reduce risks for vascular disease and death, said Dr. Alison Moore, associate professor of geriatrics at the David Geffen School of Medicine at UCLA, and the study's lead researcher.

"None of these studies have specifically looked at the interaction of alcohol use and conditions or medications that may be unsafe with even moderate amounts of alcohol use," she said. "This study shows that while moderate alcohol use may be fine for people who don't have other conditions that could be worsened by the use of alcohol, such alcohol use may not be fine if you take common medications for sleep, or for arthritis pain, or have depression, or have some gastrointestinal condition."........

Posted by: Janet      Permalink         Source

April 10, 2006, 7:37 PM CT

New Approach For Curbing Obesity

Hot fudge sundaes and french fries aside, new research suggests obesity is due at least in part to an attraction between leptin, the hormone that signals the brain when to stop eating, and a protein more recently associated with heart disease. Reporting in Nature Medicine, University of Pittsburgh scientists provide evidence that C-reactive protein (CRP) not only binds to leptin but its hold impairs leptin's role in controlling appetite. The results may help explain why obese people have so much trouble losing weight as well as point to a different target for the pharmaceutical therapy of obesity.

"There's been a lot of interest in leptin as a means to curb appetite and reduce weight but clinical trials have had disappointing results. Our studies suggest an approach that should be further studied is one that disrupts the interaction between leptin and CRP, thereby restoring leptin's ability for signaling. We need to better understand how this interaction works and investigate the underlying mechanisms involved," said Allan Z. Zhao, Ph.D., assistant professor of cell biology and physiology, University of Pittsburgh School of Medicine, and the study's senior author.

Leptin is secreted by fat - the more fat, the more leptin - yet it is named for the Greek word leptos, which means "thin." In a region of the brain called the hypothalamus, leptin binds to receptors residing on the surface of neurons, setting off signals that tell the brain to stop eating and the body to expend energy by burning calories. While obese people produce much higher levels of leptin than thin and normal-weight individuals, they are somehow resistant to its effects. Dr. Zhao and his co-authors believe the binding of CRP to leptin may be the reason this is so. Their argument seems all the more plausible since CRP also is elevated in obese people. CRP, which is produced by the liver and typically rises as part of the immune system's inflammatory response, is gaining favor as a marker for high blood pressure and heart disease risk, known complications of obesity.........

Posted by: JoAnn      Permalink         Source

April 10, 2006, 7:33 PM CT

Detecting Oral Cancer

Scientists supported by the National Institute of Dental and Craniofacial Research, part of the National Institutes of Health, report today their initial success using a customized optical device that allows dentists to visualize in a completely new way whether a patient might have a developing oral cancer.

Called a Visually Enhanced Lesion Scope (VELScope), this simple, hand-held device emits a cone of blue light into the mouth that excites various molecules within our cells, causing them to absorb the light energy and re-emit it as visible fluorescence. Remove the light, and the fluorescence of the tissue is no longer visible.

Because changes in the natural fluorescence of healthy tissue generally reflect light-scattering biochemical or structural changes indicative of developing tumor cells, the VELScope allows dentists to shine a light onto a suspicious sore in the mouth, look through an attached eyepiece, and watch directly for changes in color. Normal oral tissue emits a pale green fluorescence, while potentially early tumor, or dysplastic, cells appear dark green to black.

Testing the device in 44 people, the results of which are published online in the Journal of Biomedical Optics, the researchers found they could distinguish correctly in all but one instance between normal and abnormal tissue. Their diagnoses were confirmed to be correct by biopsy and standard pathology.........

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April 10, 2006, 7:29 PM CT

Appetite-inducing Hormone Receptor In Breast Cancer

A hormone receptor with regulatory roles as diverse as food intake, fear response, and cardiovascular function may also be involved in breast cancer, as per UC researchers.

The UC research team, led by Hassane Amlal, PhD, and Sulaiman Sheriff, PhD, report their laboratory findings on the hormone, neuropeptide Y, and its receptor in the April edition of the journal Cancer Research.

Earlier studies have shown that neuropeptide Y's receptor, known as Y1, is overproduced in human ovarian, prostate and breast cancers. This study, however, is the first to demonstrate that the Y1 receptor is actually working in breast cancer cells and can be "turned on" by excessive estrogen-a known cause of about 60 to 70 percent of breast cancers, they say.

"The high incidence and activity of the Y1 receptor in human breast tumor cells suggests that it may play an important role in breast cancer," explains Dr. Sheriff, a UC research assistant professor in the department of surgery.

Pilot data suggests that about 40 percent of all breast cancer patients have increased levels of the Y1 receptor, he says.

"We knew this receptor was overproduced in breast cancer tissue," adds Dr. Amlal, a research assistant professor in the department of internal medicine, "but now the real question is what does it do in breast cancer cells, and how can we use it as a target to fight cancer".........

Posted by: Janet      Permalink         Source

April 10, 2006, 7:13 PM CT

Obesity: Is It Genetic?

Do you have big hips or a "beer" belly? Are you "apple-shaped" or "pear-shaped"? It makes a difference, since we know that abdominal obesity is linked to diabetes and a number of other metabolic conditions, i.e., the metabolic syndrome. What's new is that, as per a new study led by scientists at Joslin Diabetes Center in Boston, both obesity and body shape seem to be controlled by important genes that are part of the mechanisms regulating normal development.

"By looking at your genes, we can tell how fat you are and how your body fat will be distributed," said lead researcher C. Ronald Kahn, M.D., President of Joslin and the Mary K. Iacocca Professor of Medicine at Harvard Medical School. In lower animals, he added, it's long been known that genes play an important role in the body's development. "Genes tell the body where the head goes and where the tail goes, what goes on the front and what goes on the back. In insects, genes determine if the wings go on the front or back and whether they will be large or small. So it's not surprising that in humans, genes may determine how a number of fat cells we have and where they are located," he said.

Together with Joslin post-doctoral fellow Stephane Gesta, Ph.D., and his colleagues at the University of Leipzig in Gera number of, the scientists for the first time used gene chips as a tool to understand what genes might control the development of fat inside the abdomen versus fat under the skin. The resulting study will be published online today, April 10, in the journal Proceedings of the National Academy of Sciences.........

Posted by: JoAnn      Permalink         Source

April 10, 2006, 7:08 PM CT

Nano-technology To Kill Cancer Cells

Research studies, based at the University of Pennsylvania, demonstrate that biodegradable nano-particles containing two potent cancer-fighting drugs are effective in killing human breast tumors. The unique properties of the hollow shell nano-particles, known as polymersomes, allow them to deliver two distinct drugs, paclitaxel, the leading cancer drug known by brand names such as Taxol, and doxorubicin directly to tumors implanted in mice. Their findings, presented online in the journal Molecular Pharamaceutics, illustrate the broad clinical potential of polymersomes.

"The system provides many advantages over other Trojan horse-style drug delivery system, and should prove a useful tool in fighting many diseases," said Dennis Discher, a professor in Penn's School of Engineering and Applied Science and a member of Penn newly established Institute for Translational Medicine and Therapeutics. "Here we show that drug-delivering polymersomes will break down in the acidic environment of the cancer cells, allowing us to target these drugs within tumor cells." .

One key feature of molecular mechanism involves putting pores in the cancer cell membranes and has been simulated with supercomputers by Michael F. Klein and Goundla Srinivas of Penn's Department of Chemistry. While cell membranes and liposomes (vesicles often used for drug-delivery) are created from a double layer of fatty molecules called phospholipids, a polymersome is comprised of two layers of synthetic polymers. The individual polymers are degradable and considerably larger than individual phospholipids but have a number of of the same chemical features. This results in a structure that looks like a very small cell or virus.........

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April 10, 2006, 7:05 PM CT

Genetic Linkage In Drug Addiction

Based on data obtained from one of the largest family sets of its kind, Yale School of Medicine scientists have identified a genetic linkage for dependence on drugs such as heroin, morphine and oxycontin.

The lead author, Joel Gelernter, M.D., professor in the Department of Psychiatry, said the scientists recruited a sample of 393 small families, most with at least two individuals with opioid dependence. They then searched genetic signposts throughout the entire genome in an effort to identify markers that, within the same family, would show that individuals who share the illness also share marker alleles, or gene variants.

This information allowed the team to identify where genes influencing opioid dependence are located. Gelernter said the scientists found evidence of gene linkage for opioid dependence. They also found good evidence of linkage in the family groups for the symptom cluster traits characterized by dependence on substances other than opioids, specifically, alcohol, cocaine and tobacco.

"These results provide a first basis to identify genes for opioid dependence from a genome-wide investigation," Gelernter said. "Research in the laboratory now is focused on finding specific genes that modify risk for opioid dependence."

He said that eventhough environment plays a significant role, it is well established that substance dependence risk is also genetically influenced. Understanding the genetic factors that influence opioid dependence risk would represent major progress toward understanding the basic biology of the disorder.........

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April 9, 2006, 8:38 PM CT

Glasses That Hear

Today a new hearing aid in the form of a pair of glasses was unveiled. These hearing-glasses are called 'Varibel' and offer older people the chance to stay active longer - free from the aesthetically unpleasing and technologically limited traditional hearing aids. Delft University of Technology in the Netherlands originally developed the hearing-glasses. Varibel developed these glasses into a consumer product in partnership with Philips, Frame Holland, the design agencies MMID and Verhoeven, and others.

Approximately 1,265,000 people in the Netherlands over the age of 60 are hearing impaired. Of these, half 22% (or around 275,000 people) use a hearing aid, but it is not always possible to hear others well if there is surrounding noise. A number of hearing aids intensify sounds from all directions. The result is that people hear noise, but not the people they are speaking to. Because people have such difficulty understanding what others are saying, a number of people - in spite of their hearing aid - have less social contact with others or must retire from their jobs earlier than desired. The hearing-glasses can provide a solution to this problem, say the experts and users who have tried and tested the Varibel.

The Varibel cannot be compared to traditional hearing aids. In each leg of the glass' frame there is a row of four tiny, interconnected microphones, which selectively intensify the sounds that come from the front, while dampening the surrounding noise. The result is a directional sensitivity of +8.2 dB. In comparison, regular hearing aids have a maximum sensitivity of +4 dB. With this solution, the user can separate the desired sounds from the undesired background noise. Dr. Cor Stengs, ENT specialist involved in the clinical tests, said of the Varibel: "Practical experience with the hearing-glasses supports the theoretical claims that the ability to understand speech is much better. There is a significant improvement in the sound quality."........

Posted by: Sue      Permalink         Source

April 9, 2006, 8:09 PM CT

Timing Of Radiation Treatments For Colon Cancer

Researchers have unexpectedly discovered that mice with the gene defect that causes colon cancer in humans can differ from normal mice in how they respond to radiation therapys. The large intestine carrying the gene defect in mice that received staggered doses of radiation was three to four times more resistant to the radiation than in control mice.

The researchers, led by Bruce Boman, M.D., Ph.D., director of the Division of Genetic and Preventive Medicine at Jefferson Medical College of Thomas Jefferson University in Philadelphia and at Jefferson's Kimmel Cancer Center and Dennis Leeper, Ph.D., professor of radiation oncology at Jefferson Medical College, say these results may have implications for treating patients with colon cancer, which is a tumor that frequently has mutations in a gene called APC.

They reported their findings this week at the 2006 annual meeting of the American Association for Cancer Research in Washington, D.C. (Stem Cell Number and Radiation Resistance During Repair in Colonic Crypts of APC Mice: Abstract no. LB-311).

Researchers have known that patients' colon tumors with APC mutations have an increased amount of survivin, a protein that halts the process of programmed cell death. This increase also appears to be associated with a rise in the number of stem cells that sit at the bottom of colonic crypts, tube-like structures that make up the lining of the intestine. Drs. Leeper and Boman wanted to see if there was a difference in stem cell number between normal mice and mice that carry a mutation in APC. To do this, they exposed both normal and mutant mice to radiation, testing their ability to repair the resulting DNA damage. They speculated that increased survivin in the mutant mice might enable more stem cells to survive and affect the response to radiation. The scientists asked if mice with an APC mutation, making them prone to develop colon cancer, are different from normal mice in radiation sensitivity and their ability to repair the damage. Normal cells can repair DNA damage from radiation, Dr. Leeper explains.........

Posted by: Sue      Permalink         Source