March 13, 2008, 9:12 PM CT
Link between common cold and ear infection
A new five-year study at the University of Texas Medical Branch at Galveston confirms the suspected close link between the two most common diseases of young children: colds and ear infections.
The study, which appears in the March 15 issue of Clinical Infectious Disease, confirmed the suspected close link between the two most common diseases of young children, viral colds and ear infections. It also identified the viruses linked to higher rates of ear infections.
Understanding how viruses and ear infections are linked will definitely help us find new ways to prevent ear infections, said Dr. Tasnee Chronmaitree, a pediatric infectious disease specialist who is the studys principal investigator. To break the link you must first understand it.
Ear infections are the driving force behind antibiotic resistance, a troubling medical issue, as physicians often administer antibiotics for the painful, persistent ailment.
Chonmaitree has studied otitis media (ear infection) for more than two decades. She said parents could best protect their children by avoiding exposure to sick children and to have their children vaccinated against influenza. She suggested that children in day care might face reduced exposure to viruses if they are enrolled in smaller day care facilities with fewer children.........
Posted by: Sue Read more Source
March 13, 2008, 9:10 PM CT
Preventing spread of ovarian cancer
A drug that blocks production of an enzyme that enables ovary cancer to gain a foothold in a new site can slow the spread of the disease and prolong survival in mice, as per a research studyby scientists from the University of Chicago Medical Center, but only if the drug is given early in the disease process.
In the recent issue of the Journal of Clinical Investigation, the scientists show that an enzyme known as MMP-2 is necessary for ovary cancer to attach itself to the sites where it tends to spread. Several drugs known as MMP inhibitors (for example, marimastat or prinomastat) inhibit the enzyme, dramatically reducing the tumor's ability to establish itself at sites beyond the ovary. But such MMP inhibitors, which were abandoned after they failed to extend survival in earlier clinical trials, have to be given before the cancer has spread.
"Our study suggests that MMP-2 inhibitors could have a significant impact on ovary cancer but only if administered quite early, before the cancer has advanced beyond the ovary," said Ernst Lengyel, assistant professor of obstetrics and gynecology at the University of Chicago.
This approach could help women who receive surgical therapy while the disease is still limited to the ovary as well as those who have successful surgery to remove all evidence of local spread of the disease. In the earlier trial, marimastat was given to women with late-stage disease that had already spread.........
Posted by: Emily Read more Source
March 13, 2008, 8:48 PM CT
Memory on Trial
Research says verbatim trace, i.e. memories of what actually happened, may reduce false memories.
The U.S. legal system has long assumed that all testimony is not equally credible, that some witnesses are more reliable than others. In tough cases with child witnesses, it assumes adult witnesses to be more reliable. But what if the legal system had it wrong?
Scientists Valerie Reyna, human development professor, and Chuck Brainerd, human development and law school professor--both from Cornell University--argue that like the two-headed Roman god Janus, memory is of two minds--that is, memories are captured and recorded separately and differently in two distinct parts of the mind.
They say children depend more heavily on a part of the mind that records, "what actually happened," while adults depend more on another part of the mind that records, "the meaning of what happened." As a result, they say, adults are more susceptible to false memories, which can be extremely problematic in court cases.
Reyna's and Brainerd's research, funded by the National Science Foundation, Arlington, Va., sparked more than 30 follow-up memory studies, a number of of them also funded by NSF. The scientists review the follow-on studies in an upcoming issue of Psychological Bulletin.
Tis research shows that meaning-based memories are largely responsible for false memories, particularly in adult witnesses. Because the ability to extract meaning from experience develops slowly, children are less likely to produce these false memories than adults, and are more likely to give accurate testimony when properly questioned.........
Posted by: JoAnn Read more Source
March 13, 2008, 8:44 PM CT
How diabetes drives atherosclerosis
Scientists have discovered how diabetes, by driving inflammation and slowing blood flow, dramatically accelerates atherosclerosis, as per research would be reported in the March 14 edition of the journal Circulation Research.
Experts once believed that atherosclerosis, or hardening of the arteries, developed when too much cholesterol clogged arteries with fatty deposits called plaques. When blood vessels became completely blocked, heart attacks and strokes occurred. Today most agree that the reaction of the body's immune system to fatty build-up, more than the build-up itself, creates heart attack risk. Immune cells traveling with the blood mistake fatty deposits for intruders, akin to bacteria, home in on them, and attack. This causes inflammation that makes plaques more likely to swell, rupture and cut off blood flow.
Making matters worse, nearly 21 million Americans have diabetes, a disease where patients cells cannot efficiently take in dietary sugar, causing it to build up in the blood. In part because diabetes increases atherosclerosis-related inflammation, diabetic patients are twice as likely to have a heart attack or stroke.
Past work has shown that high blood sugar has two effects on cells lining blood vessels as part of atheroslerosis. First, it increases the production of free radicals, highly reactive molecules that tear about sensitive cell components like DNA, causing premature cell death (apoptosis). This process also reduces the availability of nitric oxide (NO), which would otherwise enable blood vessels to relax and blood flow to increase. In contrast to diabetes, exercise and good diet bring about faster blood flow through blood vessels. The force created by fast, steady blood flow as it drags along blood vessel walls has been shown by recent studies to protect arteries from atherosclerosis. Physical force has emerged recently as a key player in bodily function, capable of kicking off biochemical processes (e.g. weightlifting thickens bone).........
Posted by: Mark Read more Source
March 13, 2008, 8:23 PM CT
Pain Receptor in Brain and Memory
Researchers have long known that the nervous system receptor known as TRPV1 can affect sensations of pain in the body. Now a group of Brown University researchers has observed that these receptors - a darling of drug developers - also may play a role in learning and memory in the brain.
In surprising new research, reported in the journal Neuron, Julie Kauer and her team show that activation of TPRV1 receptors can trigger long-term depression, a phenomenon that creates lasting changes in the connections between neurons. These changes in the brain - and the related process of neural reorganization known as long-term potentiation - are thought to bethe cellular basis for memory making.
"We've known that TRPV1 receptors are in the brain, but this is some of the first evidence of what they actually do there," Kauer said. "And the functional role we uncovered is unexpected. No one has previously linked these pain receptors to a cellular mechanism underlying memory. So we may have found a whole new player in brain plasticity".
The study findings have implications for drug development, Kauer said.
The research points out potentially effective new targets for drugs that could prevent memory loss or could possibly treat neural disorders such as epilepsy, Kauer said. The other implication may be cautionary. Drug makers already sell drugs - such as the weight-loss pill rimonabant, which is sold in Europe under the name Acomplia - that can block TRPV1 receptors. Other drugs aimed at reducing pain and inflammation by blocking or activating TRPV1 receptors are in the research pipeline. But drugs that bind to TRPV1 receptors in the central nervous system are likely to influence more than just pain-related functions, Kauer said.........
Posted by: Daniel Read more Source
March 13, 2008, 8:12 PM CT
How to block Fugitive cancer cells
Large tumors grew in bones from untreated mice (left). But when platelet activity was blocked with aspirin and APT102, bones had much smaller tumors (right).
Cancer cells get a helping hand from platelets, specialized blood cells involved in clotting. Platelets shelter and feed tumor cells that stray into the bloodstream, making it easier for cancer to spread, or metastasize. Research at Washington University School of Medicine in St. Louis suggests that inactivating platelets could slow down or prevent metastasis.
In advance online publication in the Journal of Cellular Biochemistry, the researchers report that a combination of two platelet inhibitors reduced the number and size of breast cancer or melanoma tumors that grew in the bones of laboratory mice. One of the drugs was aspirin, a widely used inhibitor of platelet clotting. The other was an experimental drug, APT102, which also prevents platelet clotting, but by a different mechanism. Both drugs were needed to reduce bone tumors.
"Past research has shown that tumor cells activate platelets and that mice with defective platelets have significantly fewer metastases," says Katherine Weilbaecher, M.D., assistant professor of medicine and of cell biology and physiology. "We also know that platelets have several traits that can aid tumor cells, and we are working to break up that potentially lethal partnership."
Metastasis of cancer cells to sites away from the main tumor can cause pain and other symptoms and greatly increases the likelihood a patient will die of the disease. In fact, more than 90 percent of cancer deaths are the result of metastasis, which is difficult to control with current therapies.........
Posted by: Scott Read more Source
March 12, 2008, 9:31 PM CT
Paradoxical Alzheimer's finding linking memory loss
Do you remember the seventh song that played on your radio on the way to work yesterday? Most of us dont, thanks to a normal forgetting process that is constantly cleaning house culling inconsequential information from our brains. Scientists at the Buck Institute now think that this normal memory loss is hyper-activated in Alzheimers disease (AD) and that this effect is key to the profound memory loss linked to the incurable neurodegenerative disorder.
Last year, this same group of scientists observed that they could completely prevent Alzheimers disease in mice genetically engineered with a human Alzheimers geneMouzheimersby blocking a single site of cleavage of one molecule, called APP for amyloid precursor protein. Normally, this site on APP is attacked by molecular scissors called caspases, but blocking that process prevented the disease. Now they have studied human brain tissue and observed that, just as expected, patients suffering from AD clearly show more of this cleavage process than people of the same age who do not have the disease. However, when they extended their studies to much younger people without Alzheimers disease, they were astonished to find an apparent paradox: these younger people displayed as much as ten times the amount of the same cleavage event as the AD patients. The scientists now believe they know why.........
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March 12, 2008, 9:29 PM CT
Ibuprofen Works Against Aspirin
Stroke patients who use ibuprofen for arthritis pain or other conditions while taking aspirin to reduce the risk of a second stroke undermine aspirin's ability to act as an anti-platelet agent, scientists at the University at Buffalo have shown.
In a cohort of patients seen by physicians at two offices of the Dent Neurologic Institute, 28 patients were identified as taking both aspirin and ibuprofen (a nonsteroidal anti-inflammatory drug, or NSAID) daily and all were found to have no anti-platelet effect from their daily aspirin.
Thirteen of these patients were being seen because they had a second stroke/TIA while taking aspirin and a NSAID, and were platelet non-responsive to aspirin (aspirin resistant) at the time of that stroke.
The scientists observed that when 18 of the 28 patients returned for a second neurological visit after discontinuing NSAID use and were tested again, all had regained their aspirin sensitivity and its ability to prevent blood platelets from aggregating and blocking arteries.
The study is the first to show the clinical consequences of the aspirin/NSAID interaction in patients being treated for prevention of a second stroke, and presents a possible explanation of the mechanism of action.
The Food and Drug Administration currently warns that ibuprofen might make aspirin less effective, but states that the clinical implications of the interaction have not been reviewed.........
Posted by: Daniel Read more Source
March 11, 2008, 10:10 PM CT
Revise guidelines for weight gain during pregnancy
Current recommendations for weight gain during pregnancy developed by the Institute of Medicine (IOM) in 1990 should be revised, as per an internationally recognized obesity expert and chairman of the department of obstetrics, gynecology and womens health at Saint Louis University.
The editorial by Raul Artal, M.D., who has conducted extensive research on obesity during pregnancy, appears in the recent issue of Expert Review of Obstetrics and Gynecology, an international medical journal.
Recommendations by the IOM, which are followed worldwide by obstetricians, encourage obese women to gain at least 15 pounds during pregnancy and specify no upper limit for weight gain. The IOM is a panel of national experts who provide advice on medical and health issues.
Overweight or obese women dont need to gain that much weight and should exercise and watch their calorie consumption during pregnancy, Artal said.
Pregnancy has become over the years a state of indulgence and confinement, he wrote. Pregnancy is an ideal time for behavior modification that includes physical activity and with proper medical supervision it can be safely prescribed.
The IOM guidelines were not grounded in scientific evidence, Artal said, and focused primarily on preventing low birth-weight deliveries, which generally occur when women who are underweight and of normal weight dont gain enough weight during pregnancy.........
Posted by: Emily Read more Source
March 11, 2008, 9:58 PM CT
Road map to safer pain control
At a time when several U.S. health insurers have discontinued payment for use of the sedative propofol during most screening colonoscopies, physicians at the University of Pennsylvania School of Medicine have discovered that an alternative way to administer the drug could both save millions of health care dollars and provide a safer way to deliver optimal pain relief.
The scientists studied two groups of patients who received patient-controlled sedation administered themselves with the push of a button during their colonoscopy. One group received a combination of the sedatives propofol and remifentanil, while the other received the drugs midazolam and fentanyl. Those in the propofol arm took only about half as long to be sedated, were able to walk quicker after the procedure, and spent much less time in the recovery room.
The findings, reported in the recent issue of the journal Anesthesia and Analgesia, shed additional light on Aetna, Humana and other large health insurers recent decisions to discontinue payment for the use of the sedative propofol during most routine colonoscopies, because it generally requires an anesthesiologist to be present to monitor for adverse reactions during the procedure. Their involvement adds several hundred dollars to the cost of the procedure, but without insurance coverage for this popular pain relief choice, physicians worry that more patients will avoid the lifesaving test, which detects and removes pre-malignant polyps. Last year, 55,000 Americans died of colorectal cancer, making it the nations second-leading cancer killer.........
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