Titanium doors to increase soldier safety

OAK RIDGE, Tenn. (UPI) -- U.S. government scientists say the next generation of combat vehicles will be equipped with titanium alloy doors to provide increased safety for soldiers.

Oak Ridge National Laboratory researchers said the doors would be made using low-cost titanium powders in a non-melt consolidation process they developed that will reduce the amount of energy required and the cost of manufacturing titanium parts from powders by up to 50 percent.

"We recently exhibited the new low-cost titanium alloy door made by ORNL for the Joint Light Tactical Vehicle, which is a next-generation combat vehicle," said Bill Peter, an ORNL researcher. "By using a titanium alloy for the door, BAE Systems was able to reduce the weight of its vehicle yet, at the same time, decrease the threat of armor-piercing rounds."

Instead of using conventional melt processing using titanium powders, with the new method the powders remain in their solid form during the entire procedure, Peter said. "This saves a tremendous amount of energy required for processing, greatly reduces the amount of scrap and allows for new alloys and engineered composites," he said.

The researchers expect lightweight corrosion-resistant titanium alloys to make their way into many other products.


Copyright 2008 by United Press International
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Method found to make tumors easier to kill

ST. LOUIS (UPI) -- U.S. medical scientists have found a vulnerability they say can be used to make cancer cells easier to heat and radiate and, therefore, easier to destroy. Washington University School of Medicine radiation oncology researchers found tumors have a built-in mechanism that protects them from hyperthermia, or heat, and most likely decreases the benefit of hyperthermia and radiation as a combined therapy.

The scientists found if they interfered with that protection, tumor cells grown in culture could be made more sensitive to hyperthermia-enhanced radiation therapy, a mainstay of cancer treatment. "Past research has shown that hyperthermia is one of the most potent ways to increase cell-killing by radiation," said senior author Associate Professor Tej Pandita.

"But now we've found that heat also enhances the activity of an enzyme called telomerase in cancer cells. Telomerase helps protect the cells from stress-induced damage and allows some of them to survive.

"We used compounds that inhibit telomerase and showed that cancer cells then become easier to destroy with hyperthermia and radiation used in combination," he added. The findings are reported in the journal Cancer Research.

Copyright 2008 by United Press International
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Caution urged for kids' anti-obesity drugs

CAMBRIDGE, Mass. (UPI) -- U.S. medical scientists are urging caution in giving children anti-obesity drugs, saying the medications might interfere with neural development.

Researchers from the Massachusetts Institute of Technology's Picower Institute for Learning and Memory say the new class of drugs -- such as rimonabant (trade name Acomplia) -- work by blocking the same receptor cells in the brain that bind to compounds found in marijuana.

Known collectively as cannabinoids, the compounds are also produced naturally by the body. The scientists said they found blocking cannabinoid receptors in laboratory mice suppressed the adaptive rewiring of the brain that is an essential task of maturation. "Our finding of a profound disruption of cortical plasticity in juvenile mice suggests caution is advised in the use of such compounds in children," said Professor Mark Bear, lead author of the study.

The work is reported in the journal Neuron.

Copyright 2008 by United Press International
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Robots may someday operate without doctors

DURHAM, N.C. (UPI) -- U.S. engineers say the world is moving closer to the day when robots will perform surgery with minimal or no guidance from a doctor. Duke University researchers say their feasibility studies may represent the first concrete steps toward achieving such a space age vision of the future.

For their experiments, the engineers used a rudimentary tabletop robot whose "eyes" used a 3-D ultrasound technology. An artificial intelligence program served as the robot's "brain," taking real-time 3-D information, processing it and giving the robot commands to perform. "In a number of tasks, the computer was able to direct the robot's actions," said Stephen Smith, director of the university's Ultrasound Transducer Group.

"We believe this is the first proof-of-concept for this approach. "Given that we achieved these early results with a rudimentary robot and a basic artificial intelligence program, the technology will advance to the point where robots -- without the guidance of the doctor -- can someday operate on people.

" The research appears online in the journal IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. A second study, published in the April issue of the journal Ultrasonic Imaging, demonstrated the robot could successfully perform a simulated needle biopsy.

Copyright 2008 by United Press International
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Lungs are illuminated for better diagnoses

SHEFFIELD, England (UPI) -- British medical scientists say they have created a technology that illuminates a person's lungs to help determine if they are correctly functioning.

The University of Sheffield researchers said their technology could result in earlier diagnosis of emphysema and smoking related damage, as well as other lung conditions and diseases.

The technique involves a person inhaling small amounts of harmless hyperpolarized noble gases (Helium-3 and Xenon-129), which are then imaged inside a MRI scanner. The gases are hyperpolarized using high power lasers by a process called optical pumping.

The high resolution images of the air spaces that are produced offer additional functional information that is currently not available with traditional X-rays and other types of scans, the researchers said.

The technology can also be used to help detect the early stages of lung obstruction in children with cystic fibrosis, something which a traditional X-ray would miss, they said.

The scientists said they are now considering using the technology to assess inhaled therapies for asthma patients and help plan radiotherapy treatment in patients with lung cancer.

Copyright 2008 by United Press International
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Study finds new aspect of sickle cell

CHAPEL HILL, N.C. (UPI) -- U.S. scientists have found sickle cell patients' blood contains clumps, or aggregates, of red and white blood cells that might contribute to the disease.

It's been long known that patients with sickle cell disease have malformed, "sickle-shaped" red blood cells that can cause sudden painful episodes when they block small blood vessels.

Now, researchers at the University of North Carolina at Chapel Hill School of Medicine have shown blood from sickle cell patients also contains clumps of red and white blood cells.

The scientists said their finding marks the first time aggregates made up of red blood cells and white blood cells have been found in whole blood from sickle cell patients. The study also shows how the red and white blood cells adhere to one another.

"If the blockages are caused by these chunks of aggregates that are circulating in the blood, and we know how the aggregates are sticking together, we potentially could design drugs to disrupt the aggregates so that they pass through the blood vessel more freely," Assistant Professor Julia Brittain said.

The study was published on-line April 18 in the British Journal of Hematology.

Copyright 2008 by United Press International
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Cancer scientists study the adenovirus

COLD SPRING HARBOR, N.Y. (UPI) -- U.S. scientists say they have clarified a complex series of biochemical steps involved in abnormal cell proliferation that can lead to cancer.

The Cold Spring Harbor (N.Y.) Laboratory researchers said they used the adenovirus -- a DNA tumor virus that causes the common cold, but whose genome contains known oncogenes, said William Tansey, who led the study with Professors Scott Lowe and Gregory Hannon.

The team focused on an adenoviral oncogene called E1A, and a protein that it codes for with the same name. Since a DNA virus is little more than a tiny segment of DNA enclosed within a protein shell, the researchers said it must find a way to enter the nucleus of a living cell and hijack the cell's reproductive machinery in order to reproduce.

"It's not adenovirus itself, but the things it does when it enters a cell, that really interest us, Tansey said.

Understanding how a tumor virus like adenovirus promotes cancer can reveal "the most vulnerable pathways and nodes that are linked to tumorigenesis," Hannon added.

The research appears in the Proceedings of the National Academy of Sciences.

Copyright 2008 by United Press International
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Childhood leukemia drug resistance studied

MEMPHIS (UPI) -- A U.S. study has revealed the basis of childhood leukemia resistance to the anti-cancer drug methotrexate.

Scientists at the St. Jude Children's Research Hospital say their findings provide new insights into the genomic basis of methotrexate resistance and differences in methotrexate response.

The researchers said their study -- the first analysis of the genetic determinants of resistance to methotrexate in childhood acute lymphoblastic leukemia, or ALL -- could offer a pathway to predicting such resistance and treatments to overcome it.

Besides its use in ALL, methotrexate is widely used to treat other cancers and some autoimmune diseases. However, until the new study there was no valid test for analyzing the genetic basis of resistance. Although 80 percent of children with the disease can be cured, determining the basis of drug resistance in the other 20 percent would help increase the cure rate.

The researchers, led by Dr. William Evans, report their findings in the journal PLoS Medicine.

Copyright 2008 by United Press International

New Parkinson's treatments possible

MINNEAPOLIS (UPI) -- U.S. scientists say they've made a discovery that might lead to new treatments for central nervous system maladies such as Parkinson's disease.

Researchers led by Karen Mesce and Joshua Puhl of the University of Minnesota discovered it's possible the human nervous system -- within each segment of the spinal cord -- might have its own "unit burst generator" to control rhythmic movements such as walking.

By studying a simpler model of locomotion in the medicinal leech, the researchers discovered each nerve cord segment has a complete unit burst generator. When a neuron fires, it sets off a chain reaction that gives rise to rhythmic movement, they said.

Mesce and her research group targeted the segmented leech for study because they have fewer and larger neurons, thereby making them easier to study.

Mesce said the study found that dopamine -- a common human hormone -- can activate each of the complete generator units.

"Because dopamine affects movement in many different animals, including humans, our studies may help to identify treatments for Parkinson's patients and those with spinal cord injury," Mesce said.

The study is available online in the Journal of Neuroscience.

Copyright 2008 by United Press International

Study: Obesity might cause some cancers

HOUSTON (UPI) -- A U.S. study suggests calorie restrictions inhibit some cancers, while obesity fuels development of epithelial cancers.

Epithelial cancers arise in the epithelium -- the tissue that lines the surfaces and cavities of the body's organs -- and comprise 80 percent of all cancers.

University of Texas M. D. Anderson Cancer Center researchers specifically found a restricted-calorie diet inhibited the development of precancerous growths in a two-step model of skin cancer, reducing the activation of two signaling pathways known to contribute to cancer growth and development.

An obesity-inducing diet, by contrast, activated the pathways, said graduate student Tricia Moore, first author of the study.

"These results, while tested in a mouse model of skin cancer, are broadly applicable to epithelial cancers in other tissues," said senior author John DiGiovanni, director of M.D. Anderson's Science Park Research Division.

The research that also included Steve Carbajal, Anna Jiang, Linda Beltran, and Steve Hursting was reported Monday in San Diego during the annual meeting of the American Association for Cancer Research.

Copyright 2008 by United Press International

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Elderly women benefit from mammograms

NEW YORK (UPI) -- A U.S. study suggests that women 70 and older benefit from yearly mammograms to help detect breast cancer.

Researchers at Jacobi Medical Center and Albert Einstein College of Medicine reviewed the mammographies of 24 cases of breast cancer in 22 patients 70 to 89 and correlated the results to surgically proven histology and lymph node involvement.

"Our initial interest was sparked by the changing mammographic guidelines in the elderly age group and the differences in the guidelines between organizations, including the American Cancer Society and American College of Radiology," lead author Dr. Jason Salsamendi said.

"During our study, we found that five patients never had a prior mammogram. Their breast cancer was detected on a baseline study. These five patients included three cases of infiltrating ductal carcinoma."

The study results encourage clinicians to continue to order screening mammography in elderly patients at yearly intervals, Salsamendi said.

The study is scheduled to be presented as an electronic exhibit during the American Roentgen Ray Society's annual meeting in Washington this week.

Copyright 2008 by United Press International

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Study links incontinence drugs with memory problems

By CARLA K. JOHNSON, Associated Press Writer

CHICAGO - Commonly used incontinence drugs may cause memory problems in some older people, a study has found. "Our message is to be careful when using these medicines," said U.S. Navy neurologist Dr. Jack Tsao, who led the study. "It may be better to use diapers and be able to think clearly than the other way around."

Urinary incontinence sometimes can be resolved with non-drug treatments, he added, so patients should ask about alternatives. Exercises, biofeedback and keeping to a schedule of bathroom breaks work for many.

U.S. sales of prescription drugs to treat urinary problems topped $3 billion in 2007, according to IMS Health, which tracks drug sales. Bladder control trouble affects about one in 10 people age 65 and older, according to the National Institute on Aging, which helped fund the study. Women are more likely to be affected than men. Causes include nerve damage, loss of muscle tone or, in men, enlarged prostate.

The research began after Tsao met a 73-year-old patient. Shortly after starting an incontinence drug, she began hallucinating conversations with dead relatives and having memory problems. Her thinking improved when she stopped the drug for several months.

Tsao and his colleagues knew of similar reports. They decided to look at a large group of people to see if they could measure an effect of these and other medications that affect acetylcholine, a chemical messenger that shuttles signals through the brain and the rest of the nervous system. The drugs block some nerve impulses, such as spasms of the bladder.

The findings, released Thursday at a meeting of the American Academy of Neurology, come from an analysis of the medication use and cognitive test scores of 870 older Catholic priests, nuns and brothers who participated in the Religious Orders Study at Chicago's Rush University Medical Center. The average age was 75.

Researchers tracked them for nearly eight years, testing yearly for cognitive decline. They asked them to recite strings of numbers backward and forward, to name as many different kinds of fruit as they could in one minute and to complete other challenges during the annual testing.

Nearly 80 percent of the study participants took one or more of a class of drugs called anticholinergics, including drugs for high blood pressure, asthma, Parkinson's disease and incontinence drugs such as Detrol and Ditropan.

The people who took the drugs had a 50 percent faster rate of cognitive decline compared to those who didn't take any. The researchers considered other risk factors for memory loss, such as age, and still found the link. The researchers found no increased risk for the memory-robbing disorder Alzheimer's in people taking the drugs.

The incontinence drugs were among the most potent and were the most frequently taken of all the anticholinergics in the study. That's why the researchers believe they are driving the memory problems, Tsao said.

Some experts said the research supports previous observations and is helpful because it measures the size of the effect.

"This paper adds important new data to the picture," said Dr. Elaine Perry of Newcastle University in England, who has done similar research but was not involved in the new study.

More research is needed on the effects of anticholinergic drugs on memory, Tsao said. Doctors should do baseline cognitive testing on patients before prescribing the drugs, he recommended.

A representative of Pfizer Inc., maker of the top-selling Detrol, said patients should always talk to their doctors about problems while taking medication.

"Detrol has been on the market since 1998. It has been prescribed more than 100 million times worldwide," said Ponni Subbiah, Pfizer's vice president of medical affairs, in an e-mail response to questions.

Confusion and memory impairment were added to prescribing information for Detrol in 2006, Subbiah said, after some patients reported the problems. Since the reports weren't part of a medical study, "the frequency of events and the role of Detrol in their causation cannot be reliably determined," he said.

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On the Net:

American Academy of Neurology: http://www.aan.com/

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