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Warning System Inadequate to Prevent Swimmers from Getting Sick
Released: 8/18/2010 10:10 AM EDT
Source: Ohio State University

Newswise — New research shows a clear link between increasing levels of E. coli bacteria in an inland Ohio lake and a greater risk that swimmers in the water will suffer a gastrointestinal illness.

Common Hypertension Drugs Can Raise Blood Pressure in Certain Patients
Commonly prescribed drugs used to lower blood pressure can actually have the opposite effect—raising blood pressure in a statistically significant percentage of patients. A new study by researchers at Albert Einstein College of Medicine of Yeshiva University suggests that doctors could avoid this problem—and select drugs most suitable for their patients—by measuring blood levels of the enzyme renin through a blood test that is becoming more widely available. The study appears in the online edition of the American Journal of Hypertension.

Newswise — An organic compound found in red wine – resveratrol – has the ability to neutralize the toxic effects of proteins linked to Alzheimer’s disease, according to research led by Rensselaer Professor Peter M. Tessier. The findings, published in the May 28 edition of the Journal of Biological Chemistry, are a step toward understanding the large-scale death of brain cells seen in certain neurodegenerative diseases.

“We’ve shown how resveratrol has very interesting selectivity to target and neutralize a select set of toxic peptide isoforms,” Tessier said. “Because resveratrol picks out the clumps of peptides that are bad and leaves alone the ones that are benign, it helps us to think about the structural differences between the peptide isoforms.”

Isoforms are different packing arrangements of a particular peptide. Deformations of a particular peptide - the Aβ1-42 peptide - have been linked to Alzheimer’s disease. Improperly folded peptides have been shown to collect in accumulations called “plaques” within the brain. Those plaques are often found near areas of cell death in diseased brains.

It is not clear that resveratrol is able to cross the blood-brain barrier, Tessier said. However, the molecule has garnered interest in recent years for its potential impact on cancer and aging.

In their research, Tessier and his co-authors generated A peptides packed together in five unique isoforms, or “arrangements” (monomer, soluble oligomer, non-toxic oligomer, fibrillar intermediates and amyloid fibrils). In their experiments, three of these arrangements were toxic to human cells, two were not.

Next, the researchers introduced resveratrol.

The resveratrol reacted with the toxic arrangements of the Aβ1-42 peptide, neutralizing their toxicity.

It did not affect the non-toxic arrangements.

“The surprise is that this molecule can target some of these packing arrangements that are toxic and rearrange them into packing arrangements that are not toxic. For those forms that are non-toxic, it doesn’t change them,” Tessier said.

Intriguingly, Tessier said, one of the toxic arrangements (the soluble oligomer) and one of the non-toxic arrangements (the non-toxic oligomer) were indistinguishable by various methods. And yet the resveratrol only affected the toxic arrangement.

The point, Tessier concludes, is that the seemingly identical non-toxic and toxic arrangements must have some distinguishing feature yet to be discovered, raising questions for future study.

“We have two things that look very similar, but one is toxic and the other isn’t,” Tessier said. “What is it that makes the bad one bad and the good one good?”

The research produced several other findings, Tessier said, including reliable methods of generating the arrangements Tessier’s team produced, and formation of one arrangement which had previously been unknown.

Last week, Tessier was named as a 2010 Pew Scholar in the Biomedical Sciences by the Pew Charitable Trusts.The distinction includes an award of $240,000 over four years and inclusion into a select community of scientists that includes three Nobel Prize winners, three MacArthur Fellows, and two recipients of the Albert Lasker Medical Research Award, according to the Pew Charitable Trusts.

Tessier was also recently awarded a five-year, $411,872 Faculty Early Career Development Award (CAREER) from the National Science Foundation (NSF) for research in the related field of protein thermodynamics and aggregation.

The CAREER Award is given to faculty members at the beginning of their academic careers and is one of NSF’s most competitive awards, placing emphasis on high-quality research and novel education initiatives.

Tessier joined the Rensselaer faculty in 2007 following a postdoctoral fellowship at the Massachusetts Institute of Technology’s Whitehead Institute for Biomedical Research. He received his bachelor’s degree in chemical engineering from the University of Maine, and went on to earn his doctoral degree in chemical engineering from the University of Delaware.

Ingredient in Red Wine May Prevent Some Blinding Diseases

Newswise — Resveratrol — found in red wine, grapes, blueberries, peanuts and other plants — stops out-of-control blood vessel growth in the eye, according to vision researchers at Washington University School of Medicine in St. Louis.

The discovery has implications for preserving vision in blinding eye diseases such as diabetic retinopathy and age-related macular degeneration, the leading cause of blindness in Americans over 50.

The formation of new blood vessels, called angiogenesis, also plays a key role in certain cancers and in atherosclerosis. Conducting experiments in mouse retinas, the researchers found that resveratrol can inhibit angiogenesis. Another surprise was the pathway through which resveratrol blocked angiogenesis. The findings are reported in the July issue of the American Journal of Pathology.

“A great deal of research has identified resveratrol as an anti-aging compound, and given our interest in age-related eye disease, we wanted to find out whether there was a link,” says Washington University retina specialist Rajendra S. Apte, MD, PhD, the study’s senior investigator. “There were reports on resveratrol’s effects on blood vessels in other parts of the body, but there was no evidence that it had any effects within the eye.”

The investigators studied mice that develop abnormal blood vessels in the retina after laser treatment. Apte’s team found that when the mice were given resveratrol, the abnormal blood vessels began to disappear.

Examining the blood-vessel cells in the laboratory, they identified a pathway — known as a eukaryotic elongation factor-2 kinase (eEF2) regulated pathway — that was responsible for the compound’s protective effects. That was a surprise because past research involving resveratrol’s anti-aging effects had implicated a different mechanism that these experiments showed not to be involved.

“We have identified a novel pathway that could become a new target for therapies,” Apte says. “And we believe the pathway may be involved both in age-related eye disease and in other diseases where angiogenesis plays a destructive role.”

Previous research into resveratrol’s influence on aging and obesity had identified interactions between the red-wine compound and a group of proteins called sirtuins. Those proteins were not related to resveratrol’s effects on abnormal blood vessel formation. Instead, the researchers say that in addition to investigating resveratrol as a potential therapy, they also want to look more closely at the eEF2 pathway to determine whether it might provide a new set of targets for therapies, both for eye disease and other problems related to abnormal angiogenesis.

Apte, an assistant professor of ophthalmology and visual sciences and of developmental biology, says because resveratrol is given orally, patients may prefer it to many current treatments for retinal disease, which involve eye injections. The compound also is easily absorbed in the body.

In mice, resveratrol was effective both at preventing new blood vessels and at eliminating abnormal blood vessels that already had begun to develop.

“This could potentially be a preventive therapy in high-risk patients,” he says. “And because it worked on existing, abnormal blood vessels in the animals, it may be a therapy that can be started after angiogenesis already is causing damage.”

Apte stresses that the mouse model of macular degeneration they used is not identical to the disease in human eyes. In addition, the mice received large resveratrol doses, much more than would be found in several bottles of red wine. If resveratrol therapy is tried in people with eye disease, it would need to be given in pill form because of the high doses required, Apte says.

There are three major eye diseases that resveratrol treatment may help: age-related macular degeneration, diabetic retinopathy and retinopathy of prematurity. Age-related macular degeneration involves the development of abnormal blood vessels beneath the center of the retina. It accounts for more than 40 percent of blindness among the elderly in nursing homes, and as baby boomers get older, the problem is expected to grow, with at least 8 million cases predicted by the year 2020.

In diabetic retinopathy, those blood vessels don’t develop beneath the retina. They grow into the retina itself. Diabetic retinopathy causes vision loss in about 20 percent of patients with diabetes. Almost 24 million people have diabetes in the United States alone.

Retinopathy of prematurity occurs when premature babies with immature retinas experience an obstruction in blood flow into the retina. In response, those children often develop abnormal blood vessels that can cause retinal detachment and interfere with vision. Worldwide, that condition blinds 50,000 newborn babies each year.

Apte says the pathway his laboratory has identified may be active not only in those blinding eye diseases, but in cancers and atherosclerosis as well. If so, then one day it might be possible to use resveratrol to improve eyesight and to prevent cardiovascular disease and some types of cancer, too.

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Khan AA, Dace DS, Ryazanov AG, Kelly J, Apte RS. Resveratrol regulates pathologic angiogenesis by a eukaryotic elongation factor-2 kinase-regulated pathway, American Journal of Pathology, vol. 177, pp. 481-492. July, 2010. DOI:10.2353/ajpath.2010.090836

This research was supported by grants from the National Eye Institute of the National Institutes of Health, the Carl Marshall Reeves and Mildred Almen Reeves Foundation, Research to Prevent Blindness, the International Retina Research Foundation, American Federation for Aging Research, American Retina Foundation and an IRRF Callahan Award.

Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked fourth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.

Increased Bicycle Riding and Brisk Walking Associated With Less Weight Gain in Women
Bicycling and brisk walking are associated with less weight gain among pre-menopausal women, especially those who are overweight and obese, according to a report in the June 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. Additionally, the report finds that slower walking does not appear to offer the same benefits as brisk walking

Beware the Rockets Red Glare and Leave Fireworks to the Experts
UAB ophthalmologists say leave fireworks to the experts and don’t use them at home. But if you do, here are some tips to keep you, and those near you, safe.