August 31, 2008, 8:18 PM CT
Telmisartan reduces outcome of heart attack or stroke
An international study led by Canadian scientists has observed that telmisartan, a medicine used to lower blood pressure, reduced the outcome of cardiovascular death, heart attack or stroke in people who are unable to tolerate a widely available and effective standard therapy.
Dr. Salim Yusuf and Dr. Koon Teo, professors in the Michael G. DeGroote School of Medicine at McMaster University and clinicians at Hamilton Health Sciences, led the study. Today the research results will be published online by The Lancet
and presented at this year's European Society of Cardiology Congress in Munich, Gera number of.
ACE inhibitors, or angiotensin-converting-enzyme inhibitors, are widely used and effective medications used to lower blood pressure. They work by helping to widen blood vessels to improve blood flow. Approximately 20 per cent of patients who could benefit from an ACE inhibitor stop taking it because of cough, kidney problems, swelling or symptomatic low blood pressure.
Telmisartan is a type of angiotensin-receptor blocker, or ARB. Like ACE inhibitors, telmisartan also lowers blood pressure, but works in a different manner. ARBs block the receptor sites in the body for angiotensin II, a naturally occurring hormone that constricts blood vessels and increases blood pressure.........
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August 21, 2008, 9:31 PM CT
Malaria researchers identify new mosquito virus
Scientists at the Johns Hopkins Bloomberg School of Public Health's Malaria Research Institute have identified a previously unknown virus that is infectious to Anopheles gambiae
the mosquito primarily responsible for transmitting malaria. As per the researchers, the discovered virus could one day be used to pass on new genetic information to An. gambiae mosquitoes as part of a strategy to control malaria, which kills over one million people worldwide each year. The study was published August 22 online in the peer-evaluated open access journal PLoS Pathogens
The virus, AgDNV, is a densonucleosis virus or "densovirus," which are common to mosquitoes and other insects, but do not infect vertebrate animals such as humans. Eventhough the virus does not appear to harm the mosquitoes, the scientists determined it is highly infectious to mosquito larvae and is easily passed on to the adults.
As per Jason Rasgon, PhD, senior author of the study, the discovery came about serendipitously while the research team was conducting experiments to determine whether Wolbachia bacteria could be used to infect An. gambiae mosquito cells. During the analysis, Xiaoxia Ren, a postdoctoral fellow with Johns Hopkins Malaria Research Institute, noticed an "artifact," that appeared as a prominent band in the gel used to detect the bacteria.........
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August 18, 2008, 9:16 PM CT
How memory deals with a change in plans
You're about to leave work at the end of the day when your cell phone rings: it's your spouse, asking that you pick up a gallon of milk on the way home. Before you head out the door, though, your spouse calls again and asks you to stop by the hardware store too. Based on your knowledge of the area and rush-hour traffic, you decide to get the milk first and the toilet plunger second. But whoops! The phone rings again. This time, it's your boss, asking you to work late. That means another change of plans.
Adjusting our behavior to such changing circumstances enables us to achieve our goals. But how, exactly, do our brains switch so elegantly and quickly from one well-entrenched plan to a newer one in reaction to a sudden change in circumstances? In the milk-hardware-boss example, do we simply remember a list of streets and turns, or do we remember a more abstract set of "rules" governing the web of relationships between the items we want to buy, our driving route and our relationships with spouse and employer?.
The answer is "both," as per scientists at The Johns Hopkins University, who have learned that two different areas of the brain are responsible for the way human beings handle complex sets of "if-then" rules. The researchers, led by Susan Courtney, associate professor of psychological and brain sciences at the Zanvyl Krieger School of Arts and Sciences, learned that rules that people must actively remember (in other words, which are not part of their everyday habits) are controlled primarily through the prefrontal cortex, which is in the very front of the brain, beneath the forehead.........
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July 29, 2008, 11:48 PM CT
New Alzheimer's predictors
By combining MRI brain scans and measurements of certain compounds in the cerebrospinal fluid, NYU scientists were able to distinguish individuals who would develop Alzheimer's disease over a two-year period. In a study of 23 people, they found atrophy in areas of the brain involved in learning and memory, and significantly higher CSF levels of phosphorylated tau and other compounds among individuals who would develop Alzheimer's in comparison to those individuals who didn't progress from mild cognitive impairment over the two-year period. This preliminary study suggests that combining these tests could help predict which individuals with mild cognitive impairment are at the highest risk for developing Alzheimer's disease.
Presentation # P3-067.Big Immune Response to Common Mouth Bacteria Associated with Alzheimer's.
Angela R Kamer, D.M.D., M.S., PhD., Assistant Professor, College of Dentistry, New York University.
In a study investigating the link between Alzheimer's disease and a heightened inflammatory-immune response, NYU scientists observed that twice as a number of subjects with probable Alzheimer's disease tested positive for antibodies in their plasma against a type of bacteria that is usually found in the mouth. The pioneering study supports a growing body of evidence that associates notable immune changes with a means of predicting and classifying Alzheimer's disease. Together with other immune markers linked to Alzheimer's disease, antibodies to these periodontal bacteria could serve to better understand the causes and mechanisms of the disease, the scientists say.........
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July 23, 2008, 4:51 PM CT
'Statins' linked to improved survival
For patients receiving kidney transplants, therapy with cholesterol-lowering "statin" drugs may lead to longer survival, reports a study in the November 2008 Journal of the American Society of Nephrology
"Statin treatment is well established for the primary and secondary prevention of cardiovascular disease in the general population, but its effectiveness in patients with kidney disease is unclear," comments Dr. Rainer Oberbauer of the Medical University of Vienna, one of the study authors. "We showed that statin treatment was indeed linked to a lower risk of death in renal transplant recipients."
The study included data on 2,041 patients receiving their first kidney transplant between 1990 and 2003. At the time of transplantation, about 15 percent of the patients were taking statin drugs to reduce their cholesterol levels. Patient survival and survival of the transplanted kidney were compared for patients who were and were not taking statins.
Overall, survival was somewhat better for patients on statin therapy. At 12 years' follow-up, 73 percent of statin-treated patients were alive, in comparison to 64 percent of patients not taking statins.
An important part of the study was the use of sophisticated statistical analyses to adjust for potentially confounding variablesincluding the fact that patients taking statins had more cardiovascular risk factors and pre-existing cardiovascular disease. The results showed a significantly lower risk of death in patients taking statins36 percent lower than in nonusers.........
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July 23, 2008, 4:37 PM CT
Human visual system could make powerful computer
Since the idea of using DNA to create faster, smaller, and more powerful computers originated in 1994, researchers have been scrambling to develop successful ways to use genetic code for computation. Now, new research from a professor at Rensselaer Polytechnic Institute suggests that if we want to carry out artificial computations, all we have to do is literally look around.
Assistant Professor of Cognitive Science Mark Changizi has begun to develop a technique to turn our eyes and visual system into a programmable computer. His findings are published in the latest issue of the journal Perception
Harnessing the computing power of our visual system, as per Changizi, requires visually representing a computer program in such a way that when an individual views the representation, the visual system naturally carries out the computation and generates a perception.
Ideally, we would be able to glance at a complex visual stimulus (the software program), and our visual system (the hardware) would automatically and effortlessly generate a perception, which would inform us of the output of the computation, Changizi said.
Changizi has begun successfully applying his approach by developing visual representations of digital circuits. A large and important class of computations used in calculators, computers, phones, and most of today's electronic products, digital circuits are constructed from assemblies of logic gates, and always have an output value of zero or one.........
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July 23, 2008, 4:24 PM CT
Omega-3 Fatty Acids Could Slow Acute Wound Healing
A recent study shows that popular fish oil supplements have an effect on the healing process of small, acute wounds in human skin. But whether that effect is detrimental, as scientists initially suspected, remains a mystery.
The omega-3 fatty acids found in fish oils are widely considered to benefit cardiovascular health and other diseases correlation to chronic inflammation because of their anti-inflammatory properties. But insufficient inflammation during the initial stage of wound healing may delay the advancement of later stages.
In the study, blister wounds on the arms of people taking fish oil supplements were in comparison to the wounds of people taking a placebo. The wounds healed in about the same amount of time - but at the local cellular level, something unexpected happened. The levels of proteins linked to initiating and sustaining inflammation were higher in the blister fluid in people who had taken the active fish oil supplements. The scientists had expected those proteins to be lowered by the increased systemic presence of omega-3 fatty acids in the blood.
"That finding was hard to explain," said Jodi McDaniel, lead author of the study and an assistant professor of nursing at Ohio State University. "These proteins may have other functions that we don't yet fully understand. And our results also suggested there could be a difference between men and women in the amount of inflammatory proteins that are produced, because on average, women had lower levels of one of the proteins." .........
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July 20, 2008, 4:58 PM CT
Enzyme expression levels and chemotherapy drug response
Why do cancer patients develop resistance to chemotherapy drugs, sometimes abruptly, after a period in which the drugs seem to be working well to reduce tumors or hold them in check? Eventhough largely a mystery to scientists, the result when this occurs is all too familiar: patients relapse and in a number of cases die when their cancers become resistant.
A team of scientists at Cold Spring Harbor Laboratory (CSHL), seeking to understand the genetic underpinnings of cancer treatment response, have identified what they regard a "significant contributor to resistance." Using a novel screening technique involving "pools" of gene-regulating short RNA molecules, they were able to determine how resistance to a drug called doxorubicin arises in lymphomas occurring in a particular strain of mice.
Toward a "global view" of factors influencing treatment response
"The method we developed is notable," said CSHL Professor Scott W. Lowe, Ph.D., a leader of the research team, "because it gives us a view of how resistance works at the level of individual molecules in living animals, and also because it can be easily extended to other chemotherapy drugs and tumor systems to give a potentially global view of factors that mediate response to cancer treatment".........
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July 16, 2008, 8:33 PM CT
Magnetic Nanoparticles to Combat Cancer
Researchers at Georgia Tech have developed a potential new therapy against cancer that attaches magnetic nanoparticles to cancer cells, allowing them to be captured and carried out of the body. The therapy, which has been tested in the laboratory and will now be looked at in survival studies, is detailed online in the Journal of the American Chemical Society.
"We've been able to use magnetic nanoparticles to capture free-floating cancer cells and then take them out of the body," said John McDonald, chair of the School of Biology at Georgia Tech and chief research scientist at the Ovarian Cancer Institute. "This technology may be of special importance in the therapy of ovary cancer where the malignancy is typically spread by free-floating cancer cells released from the primary tumor into the abdominal cavity."
The idea came to the research team from the work of Ken Scarberry, a Ph.D. student in Tech's School of Chemistry and Biochemistry. Scarberry originally conceived of the idea as a means of extracting viruses and virally infected cells when his advisor, Chemistry professor John Zhang, had another idea. He asked if the technology could be applied to cancer. Scarberry suggested it might be an effective means of preventing cancer cells from spreading.
They began by testing the treatment on mice. After giving the cancer cells in the mice a fluorescent green tag and staining the magnetic nanoparticles red, they were able to apply a magnet and move the green cancer cells to the abdominal region.........
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July 14, 2008, 4:47 PM CT
Who responds best to an antidepressant
A new Mayo Clinic study shows that variations in the serotonin transporter gene could explain why some people with depression respond better than others to therapy with citalopram (Celexa), an antidepressant medication.
The study, in the current issue of the American Journal of Medical Genetics Part B: Neuropsychiatric Genetics,
examined the serotonin transporter gene, or SLC6A4, in 1,914 study participants. The study showed that two variations in this gene have a direct bearing on how individuals might respond to citalopram. SLC6A4 produces a protein that plays an important role in achieving an antidepressant response.
In this study, scientists reviewed the influence of variations in SLC6A4 in response to citalopram therapy in white, black and Hispanic patients. Scientists observed that white patients with two distinct gene variations were more likely to experience remission of symptoms linked to major depression. No associations between the two variations and remission were found in black or Hispanic patients.
"The findings of this study represent another step in advancing individualized medicine for psychiatric patients," says David Mrazek, M.D., chair of the Mayo Clinic Department of Psychiatry and Psychology and the study's senior author. Dr. Mrazek is director of the Genomic Expression and Neuropsychiatric Evaluation (GENE) Unit at Mayo Clinic.........
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