December 4, 2006, 5:10 AM CT

Molecular 'marker' On Stem Cells Aids Research, Perhaps Therapies

A sugar molecule present on embryonic stem cells also has been found on the surface of a type of adult stem cell, a discovery that may help scientists isolate and purify adult stem cells for use in therapies aimed at bone healing, tendon repair and cartilage regeneration, scientists at UT Southwestern Medical Center report.

The molecule, called SSEA-4, was found on the surface of certain stem cells in bone marrow that give rise to fat, cartilage and bone. These so-called mesenchymal cells are a tiny component of bone marrow; the vast majority of bone marrow is made up of hematopoietic stem cells, which give rise to blood and immune cells.

Dr. Rita Perlingeiro, assistant professor in the Center for Developmental Biology and of molecular biology, said detecting SSEA-4 will aid in singling out the mesenchymal stem cells, or MSCs, for more detailed scientific study as well as for possible medical applications. The cells have shown promise in early clinical studies elsewhere, where researchers tested their use to repair bone defects and to attenuate the effects of bone loss in diseases such as osteoporosis.

The study is available online and would be reported in the Feb. 15 issue of the journal Blood.

Eventhough mesenchymal cells were discovered in the 1970s, scientists still use decades-old methods to isolate them from bone marrow, said Dr. Perlingeiro, who led the research.........

Posted by: Rose      Permalink         Source

November 30, 2006, 4:20 AM CT

New Drug Will Help Smokers

Scientists in the Oregon Health & Science University Smoking Cessation Center are studying whether the newly FDA-approved drug varenicline (Chantix) - a drug they recently showed to be more effective than the smoking cessation drug bupropion (Zyban) in helping generally healthy smokers quit - also can help smokers with the devastating lung disease known as chronic obstructive pulmonary disease (COPD).

COPD is the fourth leading cause of death in the United States. It is a disease that leads to progressive loss of lung function and is primarily a smoker's disease because very few nonsmokers are at risk for COPD. Once it has taken a firm hold, COPD has a debilitating effect on patients' lives, lifestyles and their families. They develop chronic cough, shortness of breath and difficulty breathing with exertion. Over time, as breathing becomes more and more difficult, the disease limits their ability to be active, and reduced activity further limits their quality of life. While both men and women smokers are at risk for these devastating effects, women smokers are more vulnerable than men.

Gail Cary, 73, Beaverton, Ore., has COPD. She smoked two packs a day for decades before quitting seven months ago with the support of OHSU Smoking Cessation Center staff.

"I always had an ill feeling, felt uncomfortable about smoking. I was careful to hide it, but I coughed a lot and my clothes smelled of smoke," Carey said. "Seven months ago I had a very irregular heartbeat and went to the hospital in am ambulance. I told myself if I get home, the cigarettes are gone. I felt so guilty. Since I've quit, I've felt a lot better emotionally. I'm thinking positively and I don't cough. I'm not going to go back".........

Posted by: Rose      Permalink         Source

November 29, 2006, 4:42 AM CT

Night Of The Living Enzyme

Inactive enzymes entombed in tiny honeycomb-shaped holes in silica can spring to life, researchers at the Department of Energys Pacific Northwest National Laboratory have found.

The discovery came after salvaging enzymes that had been in a refrigerator long past their expiration date. Enzymes are proteins that are not actually alive but come from living cells and perform chemical conversions.

To the research teams surprise, enzymes that should have fizzled months before perked right up when entrapped in a nanomaterial called functionalized mesoporous silica, or FMS. The result points the way for exploiting these enzyme traps in food processing, decontamination, biosensor design and any other pursuit that requires controlling catalysts and sustaining their activity.

Theres a school of thought that the reason enzymes work better in cells than in solution is because the concentration of enzymes surrounded by other biomolecules in cells is about 1,000 to 10,000 time more than in standard biochemistry lab conditions, said Eric Ackerman, PNNL chief scientist and senior author of a related study that appears today in the journal Nanotechnology. This crowding is thought to stabilize and keep enzymes active.

The silica-spun FMS pores, hexagons about 30 nanometers in diameter spread across a sliver of material, mimic the crowding of cells. Ackerman, lead author Chenghong Lei and his colleagues said crowding induces an unfolded, free-floating protein to refold; upon refolding, it reactivates and becomes capable of catalyzing thousands of reactions a second.........

Posted by: Rose      Permalink         Source

November 28, 2006, 8:01 PM CT

How Old Is Too Old?

Average paternal age is increasing in the UK (and USA) Growing evidence shows that the offspring of older fathers have an increased risk of some birth defects, some cancers, including breast , prostate and nervous system and schizophrenia. The public health implications have not been widely anticipated or debated. In October, in the Journal of Epidemiology and Community Health , a paper was published, "Advanced Paternal age: How old is too old?', led by epidemiologist Dr. Isabelle Bray.calling for a discussion of this issue.

It is thought that there is an increased risk of certain conditions due to an accumulation of mutations etc. in the sperm of older men. It was cited that the "accumulation of damage to DNA in sperm of men age 36-57 is three times that of men <35.", They include studies of childhood cancers, childhood brain cancer, retinoblastoma, acute lymphoblastic leukemia all having increased incidence with advanced paternal age. The epidemiologists state in the article that as our appreciation of the genetic contribution to disease develops it seems probable that if the current trends in the timing of fatherhood continues, the consequences at a population level may be worth considering. To illustrate the possible scale of the effects, results from a Swedish population based cohort study have been used to estimate that the increase in paternal age since 1980 could account for 10% of new cases of schizophrenia diagnosed in the UK in 2002. Adverse health outcomes should be weighed up against potential social advantages and disadvantages for children born to older parents, mindful that these societal effects are likely to change over time. Possible interventions they imagine might include health promotions advising people about the risk of delaying childbearing or changes at a societal level (family benefits, etc.) that encourage couples to have children earlier rather than later.........

Posted by: Dorje      Permalink         Source

November 15, 2006, 4:58 AM CT

New Angioplasty Procedure More Effective

Over the last several years angioplasty has exceeded coronary bypass surgery as the preferred way to treat coronary artery disease. The stents (narrow tubes inserted into the artery to facilitate blood flow) usually used in the procedure are less invasive than open-heart surgery and offer greater convenience to the patient and the ability to perform more complex procedures.

However, they are also more likely to lead to restenosis, a recurrence of artery clogging. As per findings in Journal of Cardiac Surgery, newly developed drug-eluting stents (DES) that release a drug directly to the injured blood vessels are less likely to lead to restenosis than traditionally used bare-metal stents (BMS). Controversy exists regarding the role of stents in the therapy of complex multi-vessel coronary artery disease and the potential for late complications.

While studies have observed that DES procedures limit restenosis and, consequently, improve quality of life, the associated medical care would cost patients an average of $900 more during the two-year period following the procedure than with BMS. This cost is expected to decrease within five years, however, rendering DES cost-neutral or cost-saving when in comparison to BMS.

Despite the positive outcomes linked to DES, the procedure should not be viewed as a replacement for surgery. DES have proven to be safe and effective over the short and medium term, but long term effects have not been sufficiently explored.........

Posted by: Rose      Permalink         Source

November 13, 2006, 8:15 AM CT

MRI Detects Heart Damage In Patients With Sarcoidosis

To detect heart damage early in patients with the immune system disorder sarcoidosis, who are at elevated risk of dieing from heart problems, magnetic resonance imaging is twice as sensitive as conventional methods, according to a study by Duke University Medical Center cardiologists.

By using magnetic resonance imaging, or MRI, to discover minute areas of heart damage before they grow larger, physicians may be able to take action to prevent sudden cardiac death, which is a leading cause of death in patients with sarcoidosis, the researchers said.

Typically typically sarcoidosis is characterized by the formation of tiny inflammatory growths called granulomas. Although granulomas tend to cluster in the lungs, in lymph nodes and under the skin, they also can form in the heart. When they do, it currently is difficult to determine which patients will develop heart damage, the researchers said.

"We found that MRI was sensitive in detecting small areas of damage in the hearts of patients with sarcoidosis, and we were further able to correlate these areas of damage with future adverse outcomes," said Duke cardiologist Manesh Patel, M.D., who presented the results of the study on Sunday, Nov. 12, at the annual scientific sessions of the American Heart Association, in Chicago. "The MRI technology is very good at obtaining high-resolution images of heart muscle and distinguishing normally functioning heart cells from those that are damaged or destroyed".........

Posted by: Rose      Permalink         Source

November 8, 2006, 8:56 PM CT

Gene Therapy Inhibits Epilepsy

For the first time, researchers have inhibited the development of epilepsy after a brain insult in animals. By using gene therapy to modify signaling pathways in the brain, neurology researchers found that they could significantly reduce the development of epileptic seizures in rats.

"We have shown that there is a window to intervene after a brain insult to reduce the risk that epilepsy will develop," said one of the lead researchers, Amy R. Brooks-Kayal, M.D., a pediatric neurologist at The Children's Hospital of Philadelphia and associate professor of Neurology and Pediatrics at the University of Pennsylvania School of Medicine. "This provides a 'proof of concept' that altering specific signaling pathways in nerve cells after a brain insult or injury could provide a scientific basis for treating patients to prevent epilepsy".

Dr. Brooks-Kayal and Shelley J. Russek, Ph.D., of Boston University School of Medicine were senior authors of the study in the Nov. 1 Journal of Neuroscience.

Working in a portion of the brain called the dentate gyrus, the researchers focused on one type of cell receptor, type A receptors, for the neurotransmitter gamma-aminobutyric acid (GABA). When GABA(A) receptors are activated, they inhibit the repetitive, excessive firing of brain cells that characterizes a seizure. Seizures are thought to occur, at least in part, because of an imbalance between two types of neurotransmitters: the glutamate system, which stimulates neurons to fire, and the GABA system, which inhibits that brain activity.........

Posted by: Rose      Permalink         Source

November 6, 2006, 4:52 AM CT

Hospital Costs For Children With Flu

Going into another flu season, a new study reports that hospitalizing children for influenza may cost up to three or four times the previously accepted estimates. Pediatric scientists from The Children's Hospital of Philadelphia say their finding strengthens the economic justification for broadly vaccinating children against flu.

"We found the cost of influenza-related hospitalizations in children was about $13,000 each--in comparison to most previous studies that estimated the cost at three to four thousand dollars," said study leader Ron Keren, M.D., M.P.H., a pediatrician at The Children's Hospital of Philadelphia. "This suggests that annual influenza vaccinations for children, particularly for those with certain high-risk conditions, may be more cost-effective than previously thought".

The study appears in the recent issue of Pediatrics.

The scientists analyzed billing data for 727 patients up to age 21 who were admitted to Children's Hospital with laboratory-confirmed influenza over four consecutive flu seasons, from 2000 to 2004. The study team statistically adjusted the direct medical costs to account for geographic variations in those costs.

"We found a broad range of hospital costs in the study, from approximately $7,000 each for patients treated only on the ward, to nearly $40,000 each for children cared for in the intensive care unit," said Dr. Keren. Children with low-risk conditions had hospital costs averaging $9,000 each, in comparison to those with high-risk conditions, whose costs averaged $15,000 each.........

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November 1, 2006, 8:28 PM CT

Ecologists Will Study West Nile Virus, Malaria, And Bird Flu

Over the past 20 years, unprecedented changes in biodiversity have coincided with the emergence and re-emergence of numerous infectious diseases around the world. To address this problem, the National Science Foundation (NSF) and the National Institutes of Health (NIH) have announced funding for eight projects under the Ecology of Infectious Diseases (EID) program, a multi-year, joint-agency effort now in its seventh year of funding.

"Scientists supported in the EID program are advancing basic theory correlation to infectious diseases," said James Collins, NSF Assistant Director for Biological Sciences, "and applying that knowledge to improve our understanding of how pathogens spread through populations at a time of increasing global change".

Interdisciplinary projects funded through the EID program will study how large-scale environmental events -- such as habitat destruction, biological invasions and pollution, as well as a variety of interventions -- alter the risks of viral, parasitic and bacterial diseases emerging in humans and animals.

"The joint program supports efforts to create a predictive understanding of the ecological and biological mechanisms that govern relationships among human-induced environmental changes and transmission of infectious diseases," said Samuel Scheiner, program director in NSF's biological sciences directorate, which funds the EID program along with NSF's geosciences directorate.........

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October 26, 2006, 5:14 AM CT

3-D monitor vision test for children

A new random-dot stereotest using a 3D display and infrared oculography has been found to objectively assess stereopsis in children older than three years according to an article published in the November 2006 issue of Investigative Ophthalmology & Visual Science (IOVS).

The study involved 56 children, 38 with various visual impairments and 18 with normal vision. Study participants were seated on their mother's lap or alone with their heads stabilized by a chin and front rest. Unlike a number of other tests, this new 3D monitor stereotest does not require disassociating glasses that children often find cumbersome. The random dot stimulus was presented on an autostereoscopic display which allows viewing of full-color 3D images. The stimulus recognition was objectively assessed using infrared photo-oculography. The overall accuracy of the test was found to be 95 percent.

If applicable to preverbal children, the new test may permit study of the development of stereovision under natural conditions since no glasses are necessary to see the stimuli. The new test may be useful for the objective measurement of the sensory outcome following the treatment of ophthalmic disorders in the pediatric age group. It is also a potential substitute for the Lang I and II Test and the Radom-dot E Test, which require verbal capabilities from the subject tested.........

Posted by: Emily      Permalink         Source