Posts Tagged ‘Ph.D.’

NEW EXPLANATION FOR HEART HEALTHY BENEFITS OF CHOCOLATE

Monday, February 7th, 2011

WASHINGTON

In time for the chocolate giving and chocolate noshing fest on Valentine’s Day, scientists are reporting discovery of how this treat boosts the body’s production of high density lipoprotein cholesterol (HDL) - the “good” form of cholesterol that protects against heart disease. Just as those boxes of chocolates get hearts throbbing and mouths watering, polyphenols in chocolate rev up the activity of certain proteins, including proteins that attach to the genetic material DNA in ways that boost HDL levels. Their report appears in the Journal of Agricultural and Food Chemistry, one of 39 peer-reviewed scientific journals published by the American Chemical Society.

Midori Natsume, Ph.D., and colleagues note that studies have shown that cocoa, the main ingredient in chocolate, appears to reduce the risk of heart disease by boosting levels of HDL, or “good” cholesterol, and decreasing levels of low-density lipoprotein (LDL), or “bad” cholesterol. Credit for those heart-healthy effects goes to a cadre of antioxidant compounds in cocoa called polyphenols, which are particularly abundant in dark chocolate. Until now, however, nobody knew exactly how the polyphenols in cocoa orchestrated those beneficial effects.

The scientists analyzed the effects of cocoa polyphenols on cholesterol using cultures of human liver and intestinal cells. They focused on the production of apolipoprotein A1 (ApoA1), a protein that is the major component of “good” cholesterol, and apolipoprotein B (ApoB), the main component of “bad” cholesterol. It turns out that cocoa polyphenols increased ApoA1 levels and decreased ApoB levels in both the liver and intestine. Further, the scientists discovered that the polyphenols seem to work by enhancing the activity of so-called sterol regulatory element binding proteins (SREBPs). SREBPs attach to the genetic material DNA and activate genes that boost ApoA1 levels, increasing “good” cholesterol. The scientists also found that polyphenols appear to increase the activity of LDL receptors, proteins that help lower “bad” cholesterol levels.

Other recent research on the health benefits chocolate published in ACS journals:

* New evidence that dark chocolate helps ease emotional stress

* Study finds that people are programmed to love chocolate

* Natural ACE inhibitors in chocolate, wine and tea may help lower blood pressure

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HEPA FILTERS REDUCE CARDIOVASCULAR HEALTH RISKS ASSOCIATED WITH AIR POLLUTION

Friday, January 21st, 2011

Burnaby, British Columbia
Using inexpensive air filters may help reduce cardiovascular disease risk that results from exposure to air pollution, according to researchers from Canada, who studied healthy adultsliving in a small community in British Columbia where wood burning stoves are the main sources of pollution. The researchers found that high efficiency particle air (HEPA)filters reduced the amount of airborne particulate matter, resulting in improved blood vessel health and reductions in blood markers that are associated with an increased risk of cardiovascular disease.

Ryan Allen MS, PhD
Ryan Allen MS, PhD
Assistant Professor,
Health Sciences,
Simon Fraser University,
Burnaby, BC, Canada
Photo: soeh.ubc.ca

The findings were published online ahead of the print edition of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

“Our main objectives were to evaluate the potential for a simple intervention to improve indoor air quality and reduce pollution-related cardiovascular health risks and to better understand the mechanisms that contribute to air pollution related cardiovascular health problems” said Ryan Allen, PhD, assistant professor, Simon Fraser University, Burnaby, British Columbia. “Specifically, we were interested in learning more about the effects of residential wood smoke on the endothelium, the cells that line the inside of blood vessels, and on systemic inflammation, which is related to cardiovascular disease risk.”

Previous studies on the effects of air pollution on cardiovascular disease have been conducted primarily in urban areas and have focused largely on vehicle emissions,Dr. Allen noted. The results of those studies have indicatedpollution causes inflammation in the lungs and vessels and may also cause endothelial cells to function poorly, ultimately contributing to cardiovascular disease; however, few studies have been conducted in smaller communities or communities where woodsmoke is a main source of pollution, he added.

The researchers recruited 45 adults from 25 homes. Individuals from self reported tobacco smoking households were excluded from participating. Each participant’s home was monitored for two consecutive seven-day periods, during which time a HEPA filter (Honeywell model 50300) was operated in the main activity room and a quieter HEPA filter (Honeywell 18150) was operated in the participant’s bedroom. HEPA filters were operated normally during one seven-day period and without the internal filters in place during the other period. The order of filtration or non-filtration was random and participants did not know during which period the air was being filtered. Indoor pollution sampling equipment was placed in each home’s main activity room.Participants were asked to record their activities, locations and proximity to pollution sources every 60 minutes.Of the 25 homes enrolled in the study, 13 had woodstoves in use during the study period.

At the end of each 7 day period blood and urine samples were collected from each participant and markers of cellular injury, as well as the body’s response to that injury, were measured. Endothelial function also was evaluated using a fingertip device to evaluate blood volume in small blood vessels, and air samples were collected and analyzed.

Specifically, the researchers measured reactive hyperemia, a transient increase in blood flow which follows a period of ischemia, or blood flow shortage.A reduced reactive hyperemia index indicates blood vessels have an impaired response to changes in blood flow, and is an indicator of the earliest stages of atherosclerosis. Levels of a blood protein called C-reactive protein, which increase during inflammation, were also measured.

After analyzing their data, the researchers found portable HEPA filters reduced the average concentrations of fine particulates inside homes by 60% and woodsmoke by 75%, and their use was associated with improved endothelial function (a 9.4% increase in reactive hyperemia index) and decreased inflammation (a 32.6% decrease in C-reactive protein).

“Our results support the hypothesis that systemic inflammation and impaired endothelial function, both predictors of cardiovascular morbidity, can be favorably influenced by a reduction of particle concentration and add to a growing body of evidence linking short term exposure to particulate matter with a systemic inflammatory response,” Dr. Allen said.”Reducing air pollution appears to provide health benefits even if the pollution levels are already relatively low.”

HEPA filters offer an accessible option to help reduce the risks of cardiovascular disease that may be associated with inhaling wood smoke, especially as consumers turn more frequently to woodstoves as a source of heat, he added.

“HEPA filters are a potentially useful intervention since they are relatively inexpensive to purchase and operate and can effectively remove tiny particles that can be inhaled, to improve air quality inside homes where the majority of time is spent,” Dr. Allen noted. “The importance of residential wood smoke as a source of air pollution is likely to increase due to the rising costs of other fuels.”

Dr. Allen said future studies may help determine the health benefits of programs that promote the replacement of older, highly-polluting woodstoves with cleaner burning alternatives.

“Ultimately, the best safeguard against these health risks is to minimize the amount of air pollution that is created,” he said.

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SELECTED CELLS FROM BLOOD OR BONE MARROW MAY PROVIDE A ROUTE TO HEALING BLOOD VESSELS

Friday, August 13th, 2010

Atlanta, Gorgia - August 13, 2010
Isolating cells from a patient’s blood or bone marrow that nourish blood vessels may be a safer and less arduous route to treatment of cardiovascular disease than obtaining rare stem cells, according to research from Emory University School of Medicine.

Young-sup Yoon, MD, Ph.D
Young-sup Yoon, MD, Ph.D
Emory University
School of Medicine
Photo: stemyoon.org

In recent clinical trials, doctors in several countries have tested the ability of a patient’s bone marrow cells to repair damage, such as heart attacks and peripheral artery disease, created by problems of blood flow.

“The focus has been on stem cells, but it looks like the main beneficial effects come from transplanted cells’ ability to support the growth of nearby blood vessels,” says senior author Young-sup Yoon, MD, PhD, associate professor of medicine (cardiology) at Emory University School of Medicine. “Based on this idea, we wanted to identify a population of cells enriched with the capacity to regenerate blood vessels.”

The blood vessel repairing properties of selected cells from human blood were described in the Aug. 10 issue of the Journal of the American College of Cardiology, with a related paper on cells derived from mouse bone marrow published online July 15 by the journal Circulation Research.

The first author of the JACC paper is postdoctoral fellow Sung-Whan Kim, PhD. The first author of the Circulation Research paper is Hyongbum Kim, MD, PhD, now an assistant professor in Korea.

Yoon’s team focused on the molecule CD31, also known as platelet endothelial cell adhesion molecule-1 or PECAM-1, because of its presence on endothelial cells - the cells that form the inner lining of blood vessels. In experiments with donated blood from human volunteers or mouse bone marrow cells, the researchers showed that cells with CD31 on their surfaces secrete hormones that support the growth of blood vessels.

About a third of the cells in the blood or bone marrow have CD31 on their surfaces, including some differentiated immune cells. In culture, sorted cells displaying CD31 can form tubular structures mimicking the growth of blood vessels in the body.

“We can show that after transplantation, some CD31 positive cells do become endothelial cells, but their main effect is more to support other cells than to become the building blocks,” Yoon says.

The researchers used antibodies against CD31 to sort human blood or mouse bone marrow cells into two groups: cells with CD31 and those without. They then tested these cells’ ability to spur blood vessel regrowth in mice whose hind legs had a blocked blood supply.

In the project described in Circulation Research, after two weeks more than 80 percent of the mouse hind legs transplanted with CD31 positive bone marrow cells survived, while less than 15 percent of the legs transplanted with CD31 negative cells survived. In laser Doppler images, the mice with CD31 positive cells injected into their legs had greatly enhanced blood flow and an increased number of capillaries.

Yoon says harvesting CD31 positive cells may have several advantages compared to previous methods of treating cardiovascular disease. The cells can be prepared without the need to grow them in a dish for several days, and it may not be necessary to take large volumes of blood or bone marrow from the patient - an advantage with respect to safety. In addition, cells from mice used to simulate atherosclerosis (mutant for a gene that helps clear fat from the blood and given a high fat diet) do not seem to lose their repair potential.

“Based on the insights gained from preclinical and clinical studies from several investigators, we view the use of CD31 positive cells as a second generation cardiovascular cell therapy that could be a novel option for the treatment of peripheral artery disease,” Yoon says.

He adds that CD31 positive cells may have potential for treating other conditions, including heart attack, heart failure and diabetic neuropathy, which his team is investigating in animal models.

The research was supported by the National Institutes of Health, the Department of Defense and the Korean Ministry of Education, Science and Technology.

Learn more about Emory’s health sciences: http://emoryhealthblog.com

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NEW EVIDENCE THAT CHILI PEPPER INGREDIENT FIGHTS FAT

Wednesday, July 21st, 2010

KYUNGBUK KOREA , July 21, 2010
Capsaicin, the stuff that gives chili peppers their kick, may cause weight loss and fight fat buildup by triggering certain beneficial protein changes in the body, according to a new study on the topic. The report, which could lead to new treatments for obesity, appears in ACS’ monthly Journal of Proteome Research.

Chili peppers
Chili peppers contain
an ingredient that may
cause weight loss
and fight fat.

Jong Won Yun and colleagues point out that obesity is a major public health threat worldwide, linked to diabetes, high blood pressure, heart disease, and other health problems. Laboratory studies have hinted that capsaicin may help fight obesity by decreasing calorie intake, shrinking fat tissue, and lowering fat levels in the blood. Nobody, however, knows exactly how capsaicin might trigger such beneficial effects.

In an effort to find out, the scientists fed high-fat diets with or without capsaicin to lab rats used to study obesity. The capsaicin-treated rats lost 8 percent of their body weight and showed changes in levels of at least 20 key proteins found in fat. The altered proteins work to break down fats. “These changes provide valuable new molecular insights into the mechanism of the antiobesity effects of capsaicin,” the scientists say.

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HOW RED WINE MAY SHIELD BRAIN FROM STROKE DAMAGE

Wednesday, April 21st, 2010

Johns Hopkins researchers discover pathway in mice for resveratrol’s apparent protective effect Researchers at Johns Hopkins say they have discovered the way in which red wine consumption may protect the brain from damage following a stroke.

Sylvain Dore, Ph.D.
Sylvain Dore, Ph.D. -
professor of anesthesiology
and critical care medicine
and pharmacology and
molecular sciences at the
Johns Hopkins University
School of Medicine

Two hours after feeding mice a single modest dose of resveratrol, a compound found in the skins and seeds of red grapes, the scientists induced an ischemic stroke by essentially cutting off blood supply to the animals’ brains. They found that the animals that had preventively ingested the resveratrol suffered significantly less brain damage than the ones that had not been given the compound.

Sylvain Dore, Ph.D., an associate professor of anesthesiology and critical care medicine and pharmacology and molecular sciences at the Johns Hopkins University School of Medicine, says his study suggests that resveratrol increases levels of an enzyme (heme oxygenase) already known to shield nerve cells in the brain from damage. When the stroke hits, the brain is ready to protect itself because of elevated enzyme levels. In mice that lacked the enzyme, the study found, resveratrol had no significant protective effect and their brain cells died after a stroke.

“Our study adds to evidence that resveratrol can potentially build brain resistance to ischemic stroke,” says Dore, the leader of the study, which appears online in the journal Experimental Neurology.

Dore cautions against taking resveratrol supplements, available alongside vitamins and minerals and on websites touting its benefits, because it is unclear whether such supplements could do harm or good. He has not tested resveratrol in clinical trials. And while resveratrol is found in red grapes, it’s the alcohol in the wine that may be needed to concentrate the amounts of the beneficial compound. Dore also cautions that drinking alcohol carries risks along with potential benefits.

He also notes that even if further research affirms the benefits of red wine, no one yet knows how much would be optimal to protect the brain, or even what kind of red wine might be best, because not all types contain the same amount of resveratrol. More research is needed, he says.

Dore says his research suggests that the amount needed could end up being quite small because the suspected beneficial mechanism is indirect. “Resveratrol itself may not be shielding brain cells from free radical damage directly, but instead, resveratrol, and its metabolites, may be prompting the cells to defend themselves,” he suggests.

“It’s not likely that brain cells can have high enough local levels of resveratrol to be protective,” he says. The resveratrol is needed to jump-start this protective enzymatic system that is already present within the cells. “Even a small amount may be sufficient,” Dore says.

Dore says his ongoing research also suggests some therapeutic benefits to giving resveratrol to mice after a stroke to limit further neuronal damage.

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PIECE FROM CHILDHOOD VIRUS MAY SAVE TRAUMA LIVES

Monday, September 7th, 2009

Research presented Sept. 6 at European complement conference

A harmless shard from the shell of a common childhood virus may halt a biological process that kills a significant percentage of battlefield casualties, heart attack victims and oxygen deprived newborns, according to research presented Sunday, September 6, 2009, at the 12th European meeting on complement in human disease in Budapest, Hungary.

Introducing the virus’s shell in vitro shuts down what is known as the complement response, a primordial part of the immune system that attacks and destroys the organs and vascular lining of people who have been deprived of oxygen for prolonged periods, according to researchers at Children’s Hospital of The King’s Daughters (CHKD) and Eastern Virginia Medical School (EVMS), in Norfolk, Va.

The complement response kicks in after the victim has been revived, in what is known as a reperfusion injury. It does its work slowly but unrelentingly, killing soldiers, infants or heart attack victims over the course of days.

“To find a way to manipulate the complement system pharmacologically has been like a search for the Holy Grail,” said one of the lead researchers, Dr. Kenji Cunnion, an infectious disease physician at CHKD and an associate professor of pediatrics at EVMS.

While Cunnion and Neel Krishna, Ph.D., a pediatric virologist at CHKD and assistant professor of microbiology at EVMS, focus on pediatric research, they see clear military applications.

“The complement reaction is one of the major causes of death of the battlefield,” said Krishna. “By the time you get a victim to the hospital, it may be too late.”

Dr. L.D. Britt, M.D., MPH, Brickhouse professor and chairman of surgery at EVMS, agrees.

“Hemorrhagic shock is the leading cause of death in combat trauma and reperfusion injury plays a significant role both in increased mortality and increased brain damage,” said Britt.

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RESEARCH LINKS SOCIAL STRESS TO HEART DISEASE

Wednesday, August 5th, 2009

WINSTON-SALEM, N.C. - A new study done by researchers at Wake Forest University School of Medicine shows that social stress could be an important precursor to heart disease by causing the body to deposit more fat in the abdominal cavity, speeding the harmful buildup of plaque in blood vessels, a stepping stone to the number one cause of death in the world. The findings could be an important consideration in the way the United States and other Western countries try to stem the rapid rise of obesity, said Carol A. Shively, Ph.D., a professor of pathology and the study’s principal investigator.

The study appears as the cover story of the current issue of Obesity, the peer-reviewed journal of the Obesity Society.

“We are in the midst of an obesity epidemic,” Shively said. “Much of the excess fat in many people who are overweight is located in the abdomen, and that fat behaves differently than fat in other locations. If there’s too much, it can have far more harmful effects on health than fat located in other areas.”

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