February 3, 2010, 2:21 PM CT

Reducing complications of obesity

Eventhough obesity is a risk factor for diabetes and coronary heart disease worldwide, only some obese individuals go on to develop these metabolic complications, while others are relatively protected. Defining these protective factors could help researchers prevent disease in the wider population.

To this end, a research team at the Gladstone Institute of Cardiovascular Disease, led by Suneil Koliwad, MD, PhD, recently added new details that link obesity to diabetes and heart disease.

When individuals become obese from overeating, cells called adipocytes located in the fat tissue fill up with dietary fats and begin to die. Immune cells called macrophages move out of the blood stream and into this tissue, where they accumulate around dying adipocytes. As the macrophages work to clear away the dead cells, they are exposed to large amounts of dietary fat that can result in unwanted consequences. Exposure to saturated fats, in particular, causes the macrophages to enter an inflammatory state. In this state, the macrophages secrete cytokines, such as tumor necrosis factor (TNF) alpha, that encourage the development of insulin resistance, diabetes, and heart disease.

The Gladstone team hypothesized that enhancing the capacity of macrophages to store dietary fats might alter this process. To do this, they focused on an enzyme called DGAT1, which makes triglycerides from dietary fats for storage as cellular energy reserves......... Posted by: JoAnn      Read more         Source

January 21, 2010, 8:21 AM CT

COPD and heart function

A common lung condition, COPD (chronic obstructive pulmonary disease) diminishes the heart's ability to pump effectively even when the disease has no or mild symptoms, as per research reported in the Jan. 21 issue of the New England Journal (NEJM) The study is the first time scientists have shown strong links between heart function and mild COPD. The research was funded by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health.

Scientists have long known that severe cases of COPD have harmful effects on the heart, decreasing its ability to pump blood effectively. The new results suggest that these changes in the heart occur much earlier than previously believed, in mild cases and even before symptoms appear. One in five Americans over the age of 45 has COPD, but as a number of as half of them may not even be aware of it.

"This study shows that COPD, even in its mildest form, is linked to diminished heart function," said NHLBI Acting Director Susan B. Shurin, M.D. "We now have evidence that the presence of even mild COPD may have important health implications beyond the lungs."

COPD is the fourth leading cause of death in the United States, and it is strongly linked to smoking. COPD often involves destruction of lung tissue, called emphysema, as well as narrowed airways, persistent cough, and mucus production, known as chronic obstructive bronchitis. These abnormalities impair the flow of air in the lungs and make breathing more difficult......... Posted by: Scott      Read more         Source

January 21, 2010, 8:16 AM CT

Heart Attack Victims Who Have ECGs

A recent study observed that individuals experiencing chest pain who had electrocardiogram (ECG or EKG) evaluations previous to arriving at the hospital experienced a significantly reduced time-to-treatment or door-to-balloon (D2B) time. When EMS personnel responding to cardiac emergencies obtained ECGs of the subjects in the field, the mean D2B time was 60.2 minutes compared with 90.5 minutes for in-hospital ECGs. This advanced evaluation significantly reduced D2B by allowing patients to bypass the ER and be transported directly to the cardiac catheterization laboratory (CCL) for reperfusion therapy. Details of the study appear in the January 2010 issue of Catheterization and Cardiovascular Interventions, published by Wiley-Blackwell on behalf of The Society for Cardiovascular Angiography and Interventions.

ST-segment elevation myocardial infarction (STEMI), when a blood clot totally obstructs a coronary artery, is treated with reperfusion treatment to reestablish blood flow as quickly as possible. Previous studies showed that rapid time-to-treatment with primary percutaneous coronary intervention (PPCI), previously known as angioplasty, was linked to lower mortality rates, and for each 30 minutes of delay the relative risk of 1 year mortality increased by 7.5%. In an effort to improve patient survival rates, the American College of Cardiology (ACC) and the American Heart Association (AHA) developed national guidelines that state hospitals treating STEMI patients with PPCI should strive to achieve a median door-to-balloon time of less than 90 minutes......... Posted by: Daniel      Read more         Source

January 13, 2010, 8:23 AM CT

Hypertension Linked to Dementia

Older women with high blood pressure are at increased risk for developing brain lesions that cause dementia during the later part of life, as per data from the Women's Health Initiative Memory Study (WHIMS). The findings were reported in the December 2009 online issue of the Journal of Clinical Hypertension.

The research was conducted as part of the Women' Health Initiative (WHI), the largest multi-site longitudinal study looking at health risks among postmenopausal women. WHIMS, which involves a subgroup of the women enrolled in WHI, looks at the influence of hormone treatment on thinking and memory. All the women in WHIMS were 65 or older.

Upon enrolling in the trial and annually during their participation in it, the women had their blood pressure measured and underwent tests to measure their cognitive ability. Some of the WHIMS participants - 1,403 of them - also underwent magnetic resonance imaging (MRI) at 14 U.S. academic centers in 2005 and 2006. All of these women were free of dementia when they enrolled. Examination of the data on these 1,403 women was led by Lewis H. Kuller, M.D., Dr.P.H., of the University of Pittsburgh, in conjunction with scientists at other WHI centers, including Dr. Sylvia Wassertheil-Smoller, Ph.D., professor of epidemiology and population health and the Dorothy and William Manealoff Foundation & Molly Rosen Chair in Social Medicine at Albert Einstein College of Medicine. Dr. Wassertheil-Smoller is also the principal investigator of Einstein's WHI and WHIMS studies......... Posted by: Daniel      Read more         Source

December 23, 2009, 11:01 PM CT

Anti-inflammatory drugs interfere with aspirin

A newly released study conducted at Ben-Gurion University of the Negev (BGU) reveals that Celebrex and other anti-inflammatory coxib medications may counter the positive effects of aspirin in preventing blood clots.

The research, reported in the Proceedings of the National Academy of Sciences (PNAS), indicates that people who are taking aspirin and coxibs together are in fact inhibiting the aspirin's effectiveness in preventing heart attacks and strokes.

"This finding strongly suggests that humans who are consuming coxibs and a low dose of aspirin simultaneously are exposed to a greater risk of cardiovascular events," said Professor Gilad Rimon, Department of Clinical Pharmacology, Ben-Gurion University of the Negev in Israel.

In the past decade, a new group of anti-inflammatory drugs, coxibs, which include Celebrex and Arcoxia was developed to treat arthritis as well as other pain. Arthritis patients who take Celebrex are instructed to take low-dose aspirin to counteract Celebrex's own potential clot-promoting effect.

Aspirin is the oldest and one of the most effective non steroidal anti-inflammatory drugs. It is also well known for its ability to prevent the blood clots that can potentially lead to heart attack and stroke. Therefore, doctors often advise patients who are more prone to heart-related illnesses to take a daily tablet of low dose aspirin (81 mg). Approximately, 50 million Americans take aspirin every day to reduce their risk of cardiovascular diseases......... Posted by: Daniel      Read more         Source

December 15, 2009, 11:36 PM CT

Chip capable of growing cardiac tissue

Johns Hopkins biomedical engineers, working with colleagues in Korea, have produced a laboratory chip with nanoscopic grooves and ridges capable of growing cardiac tissue that more closely resembles natural heart muscle. Surprisingly, heart cells cultured in this way used a "nanosense" to collect instructions for growth and function solely from the physical patterns on the nanotextured chip and did not require any special chemical cues to steer the tissue development in distinct ways. The researchers say this tool could be used to design new therapies or diagnostic tests for cardiac disease.

The device and experiments using it were described in this week's online Early Edition of Proceedings of the National Academy of Sciences. The work, a collaboration with Seoul National University, represents an important advance for scientists who grow cells in the lab to learn more about cardiac disorders and possible remedies.

"Heart muscle cells grown on the smooth surface of a Petri dish, would possess some, but never all, of the same physiological characteristics of an actual heart in a living organism," said Andre Levchenko, a Johns Hopkins associate professor of biomedical engineering at the Whiting School of Engineering. "That's because heart muscle cells-cardiomyocytes-take cues from the highly structured extracellular matrix or ECM, which is a scaffold made of fibers that supports all tissue growth in mammals. These cues from the ECM influence tissue structure and function, but when you grow cells on a smooth surface in the lab, the physical signals can be missing. To address this, we developed a chip whose surface and softness mimic the ECM. The result was lab-grown heart tissue that more closely resembles the real thing"......... Posted by: Daniel      Read more         Source

December 2, 2009, 11:23 PM CT

Adult stem cells to repair heart attack damage

Adult stem cells may help repair heart tissue damaged by heart attack as per the findings of a newly released study to be reported in the December 8 issue of the Journal of the American College of Cardiology Results from the Phase I study show stem cells from donor bone marrow appear to help heart attack patients recover better by growing new blood vessels to bring more oxygen to the heart.

Rush University Medical Center was the only Illinois site and one of 10 cardiac centers across the country that participated in the 53-patient, double-blind, placebo-controlled Phase I trial. Rush is now currently enrolling patients for the second phase of the study.

Scientists say it is the strongest evidence thus far indicating that adult stem cells can actually differentiate, or turn into heart cells to repair damage. Until now, it has been believed that only embryonic stem cells could differentiate into heart or other organ cells.

"The results point to a promising new therapy for heart attack patients that could reduce mortality and lessen the need for heart transplants," said Dr. Gary Schaer, head of the Rush Cardiac Catheterization Laboratory and study principal investigator at Rush.

In phase I of the study, a group of 53 patients who had heart attacks in the prior ten days received adult mesenchymal stem cells and were kept under close study for two years......... Posted by: Daniel      Read more         Source

December 1, 2009, 8:20 AM CT

Heart disease may accompany narrowing in leg arteries

Results of a randomized, controlled clinical trial presented today at the annual meeting of the Radiological Society of North America (RSNA) reveal that one in five patients with narrowing or blockage in arteries that supply blood to the legs and other parts of the body also have significant but silent coronary artery disease.

Peripheral arterial disease (PAD) occurs when plaque, a combination of fat, cholesterol and other substances, builds up in the arteries, limiting the flow of oxygen-rich blood throughout the body. PAD commonly affects arteries that carry blood to the legs, causing poor circulation, discomfort and pain. More than eight million Americans have PAD, as per the American Heart Association.

As per the National Heart, Lung and Blood Institute, coronary artery disease is the most common type of heart disease and the leading cause of death in the U.S.

"PAD patients, including those experiencing no symptoms of heart disease, are known to be at high risk for cardiovascular events such as a heart attack or stroke," said Rozemarijn Vliegenthart Proenca, M.D., Ph.D., radiology resident at the University Medical Center Groningen in the Netherlands. "The purpose of our clinical trial was to investigate whether noninvasive imaging of the heart and subsequent therapy of PAD patients result in a decrease in cardiac events in comparison to standard care"......... Posted by: Daniel      Read more         Source

November 25, 2009, 7:57 AM CT

Do not smoke near your loved ones going for heart transplant

A study conducted at the University of Maryland School of Medicine in Baltimore provides the first direct evidence that cigarette smoke exposure previous to a heart transplant in either the donor, recipient, or both, accelerates the death of a transplanted heart. The study, published this month in the journal Circulation, showed that tobacco smoke leads to accelerated immune system rejection of the transplanted heart, heightened vascular inflammation and increased oxidative stress, and a reduction in the transplanted organ's chance of survival by 33-57 percent.

The study, conducted in rats, involved exposure to levels of tobacco equivalent to that of a habitual, light-to-moderate-range smoker and included comparisons between smoking and non-smoking donors and recipients.

"Our research shows that if a heart donor has been a habitual smoker, and you put that heart in a non-smoking recipient, that heart won't work; it will be rejected," says the study's senior author, Mandeep R. Mehra, M.B.B.S., professor of medicine, head of the Division of Cardiology at the University of Maryland School of Medicine and chief of cardiology at the University of Maryland Medical Center. "This study shows beyond a shadow of a doubt how smoking affects transplantation".

This is the first study to look at the impact of smoking in heart donors, as per the principal investigator, Ashwani K. Khanna, Ph.D., associate professor of medicine at the University of Maryland School of Medicine. "There are already a number of risk factors that physicians and surgeons must consider when they try to match a donor with a recipient. This study makes clear that smoking in both the donor and the recipient should also become a part of the risk calculus in organ donation," says Dr. Khanna......... Posted by: Daniel      Read more         Source

November 25, 2009, 7:54 AM CT

Remove that salt shaker from the dining table

Eating high amounts of salt is associated with a significantly higher risk of strokes and cardiovascular disease, states a paper published recently in the British Medical Journal

The research was carried out jointly by the World Health Organization's Collaborating Centre for Nutrition, based at the University of Warwick and University Hospital in Coventry, UK, and the European Society of High blood pressure Excellence Centre in High blood pressure based at the Department of Clinical and Experimental Medicine, Federico II University Medical School in Naples, Italy.

The study looked at the relationship between the level of habitual dietary salt intake and the occurrence of stroke and cardiovascular disease by reviewing 13 prospective studies from the UK, Japan, USA, The Netherlands, Finland and China, including more than 170,000 participants, followed up for 3.5 to 19 years, who experienced nearly 11,000 vascular events.

The study provides unequivocal evidence of the direct link between high dietary salt intake and increased risk of stroke and cardiovascular disease. A 5 g lower daily salt intake would reduce stroke by 23% and total cardiovascular disease by 17%, thus averting 1.25 million fatal and non-fatal strokes, and almost 3 million vascular events worldwide each year. The effect is greater, the larger the difference in salt intake and increases with time......... Posted by: Daniel      Read more         Source

November 16, 2009, 8:00 AM CT

Delivering antioxidant to injured heart cells

Scientists at Emory University and the Georgia Institute of Technology have developed microscopic polymer beads that can deliver an antioxidant enzyme made naturally by the body into the heart.

Injecting the enzyme-containing particles into rats' hearts after a simulated heart attack reduced the number of dying cells and resulted in improved heart function days later.

Michael Davis, PhD, is presenting the results Sunday evening at the American Heart Association Scientific Sessions in Orlando. Davis is assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.

The enzyme in the particles, called superoxide dismutase (SOD), soaks up toxic free radicals produced when cells are deprived of blood during a heart attack. Previously researchers have tried injecting SOD by itself into injured animals, but it doesn't seem to last long enough in the body to have any beneficial effects.

"Our goal is to have a treatment to blunt the permanent damage of a heart attack and reduce the probability of heart failure during the later part of life," Davis says. "This is a way to get extra amounts of a beneficial antioxidant protein to the cells that need it".

The simulated heart attacks caused a 20 percent decrease in the ability of the rats' hearts to pump blood that was completely prevented by the particles, he says......... Posted by: Daniel      Read more         Source

November 16, 2009, 7:53 AM CT

Vitamin D deficiency and cardiovascular disease

While mothers have known that feeding their kids milk builds strong bones, a newly released study by scientists at the Heart Institute at Intermountain Medical Center in Salt Lake City suggests that Vitamin D contributes to a strong and healthy heart as well and that inadequate levels of the vitamin may significantly increase a person's risk of stroke, heart disease, and death, even among people who've never had heart disease.

For more than a year, the Intermountain Medical Center research team followed 27,686 patients who were 50 years of age or older with no previous history of cardiovascular disease. The participants had their blood Vitamin D levels tested during routine clinical care. The patients were divided into three groups based on their Vitamin D levels normal (over 30 nanograms per milliliter), low (15-30 ng/ml), or very low (less than 15 ng/ml). The patients were then followed to see if they developed some form of heart disease.

Scientists observed that patients with very low levels of Vitamin D were 77 percent more likely to die, 45 percent more likely to develop coronary artery disease, and 78 percent were more likely to have a stroke than patients with normal levels. Patients with very low levels of Vitamin D were also twice as likely to develop heart failure than those with normal Vitamin D levels......... Posted by: Daniel      Read more         Source

November 10, 2009, 8:25 AM CT

Waiting time for chest pain

Emory University Rollins School of Public Health scientists will present Nov. 10 on a range of topics at the American Public Health Association's annual meeting in Philadelphia, including a study that examined compliance with national recommendations that a doctor screen chest pain patients within 10 minutes of their arrival to the Emergency Department (ED).

Additional public health research findings from Emory researchers are highlighted below.

Disparities in emergency room waiting times for chest pain patients

The American College of Cardiology and the American Heart Association recommend an electrocardiogram be performed and shown to a doctor within 10 minutes of a chest pain patient's arrival to the emergency department (ED). Emory scientists examined disparities in waiting times to see a doctor for patients complaining of chest pain.

They observed that only 30 percent of all chest pain patients were seen within the recommended 10 minutes. In addition, racial disparities affected all chest pain patients. African Americans were seen by an ED doctor later than whites, scientists noted.

Data were extracted from the 2003-2006 National Hospital Ambulatory Medical Care Survey.

Untangling the Web: An exploratory look at the impact of parental discipline and primary caregiver support on high-risk taking behavior........ Posted by: Daniel      Read more         Source

November 5, 2009, 8:45 AM CT

How the heart is formed?

While studying how the heart is formed, researchers at the University of Pennsylvania School of Medicine serendipitously found a novel cellular source of atrial fibrillation (AF), the most common type of abnormal heart beat. Jonathan Epstein, MD, William Wikoff Smith Professor, and Chair, Department of Cell and Developmental Biology, and Vickas Patel, MD, PhD, Assistant Professor of Medicine, have identified a population of cells in the atria of the heart and pulmonary veins of humans and mice that appear to be the seat of AF. The finding may lead to a more precise way to treat AF, with reduced side effects. Their findings appear online in the Journal of Clinical Investigation.

This group of cells expresses the protein DCT, which is also involved in making the skin pigment melanin and in the detoxification of free radicals. The scientists also showed that the DCT-expressing cells in the mouse heart were a distinct cell type from heart-muscle cells and pigment-producing cells, eventhough they conduct electrical currents important for coordinated contraction of the heart. The location of these cells in the pulmonary veins suggested their possible role in AF because AF can arise in these blood vessels. Atrial fibrillation is a very common and debilitating disease that greatly affects quality of life......... Posted by: Daniel      Read more         Source

November 4, 2009, 8:04 AM CT

Heart disease risk among post-menopausal women

Postmenopausal women who have higher testosterone levels appears to be at greater risk of heart disease, insulin resistance and the metabolic syndrome in comparison to women with lower testosterone levels, as per a newly released study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM). This new information is an important step, say researchers, in understanding the role that hormones play in women's health.

"For a number of years, androgens like testosterone were thought to play a significant role in men only and to be largely irrelevant in women," said Anne Cappola, MD, of the University of Pennsylvania School of Medicine in Philadelphia. "It is now largely accepted that premenopausal women with polycystic ovary syndrome, a condition in which androgens are elevated, have increased health risks. However, the clinical relevance of testosterone in women over the age of 65 had remained uncertain until this recent study".

In this study, scientists measured levels of testosterone in 344 women, aged 65-98 years. They observed that women with the highest testosterone levels in the top 25 percent of this study group were three times as likely to have coronary heart disease in comparison to women with lower testosterone levels. These women were also three times as likely to have a group of metabolic risk factors called the metabolic syndrome in comparison to women with lower testosterone levels......... Posted by: Daniel      Read more         Source

October 26, 2009, 7:43 AM CT

Obesity, blood pressure and cholesterol

Obese patients taking medications to lower their blood pressure and cholesterol levels are less likely to reach recommended targets for these cardiovascular disease risk factors than their normal weight counterparts, as per new research presented at the 2009 Canadian Cardiovascular Congress hosted by the Canadian Cardiovascular Society and the Heart and Stroke Foundation of Canada.

Dr. Vineet Bhan, a resident at the University of Toronto, sought to determine whether there were differences in reaching guideline-recommended targets for blood pressure and cholesterol levels as per body mass index (BMI) in a large number of individuals deemed to be at high risk for heart disease and stroke.

"In Canada, these high risk patients frequently do not reach their blood pressure and cholesterol targets," says Dr. Bhan. "The goal of our study was to see if obesity could be a factor."

He says that other studies have looked at obese individuals in the general population and found they were more likely to have high blood pressure, high cholesterol, and diabetes. "This, to our knowledge, is the first study looking at patients with established cardiovascular disease who are on therapy to see how obesity relates to the control of these risk factors," he says.

The study recruited 7,357 high risk patients who had a history of coronary artery disease, cerebrovascular disease, peripheral vascular disease, or diabetes plus additional cardiovascular risk factors from nine Canadian provinces. This observational study, based on two outpatient registries, took place from 2001 to 2004, recruiting 95 per cent of the patients from family doctor offices. The registries were led by senior co-author, Dr. Shaun Goodman, and coordinated by the Canadian Heart Research Centre......... Posted by: Daniel      Read more         Source

October 26, 2009, 7:41 AM CT

Women do have same the heart attack symptoms as men

The gender difference between men and women is a lot smaller than we've been led to believe when it comes to heart attack symptoms, as per a newly released study presented to the Canadian Cardiovascular Congress 2009, co-hosted by the Heart and Stroke Foundation and the Canadian Cardiovascular Society.

"Both the media and some patient educational materials frequently suggest that women experience symptoms of a heart attack very differently from men," says cardiac nurse Martha Mackay, a Canadian Institutes of Health Research clinical research fellow and doctoral student at the UBC School of Nursing. "These findings suggest that this is simply not the case".

Her team's study of 305 consecutive patients undergoing angioplasty − which briefly causes symptoms similar to a heart attack − found no gender differences in rates of chest discomfort or other 'typical' symptoms such as arm discomfort, shortness of breath, sweating, nausea, indigestion-like symptoms, and clammy skin.

While both women and men may experience typical or non-typical symptoms, the major difference was that female patients were more likely to have both the classic symptoms of heart attack plus throat, jaw, and neck discomfort.

"Clear educational messages need to be crafted to ensure that both women and healthcare professionals realize the classic symptoms are equally common in men and women," says Mackay......... Posted by: Daniel      Read more         Source

October 26, 2009, 7:30 AM CT

Survival after heart attack improves

In recent years, women, especially younger women, experienced larger improvements in hospital mortality after myocardial infarction (MI) than men, as per a research studyreported in the Oct. 26, 2009 issue of Archives of Internal Medicine

Over the last decade several studies showed that younger women, but not older ones, are more likely to die in the hospital after MI than age-matched men. A team of Emory University scientists examined whether such mortality differences have declined in recent years.

"We observed that the number of younger women who die in the hospital after a heart attack, compared with men in the same age group, has narrowed over the last few years," says study leader Viola Vaccarino, MD, PhD, professor of medicine (cardiology), and director of the Emory Program in Cardiovascular Outcomes Research and Epidemiology. Vaccarino says changes in patient characteristics and therapys over time accounted in part for the changing mortality trends.

Often referred to as a heart attack, MI occurs when the blood supply to part of the heart is interrupted. This decreased blood supply is usually due to blockage of a coronary artery and if left untreated can cause damage and/or death (infarction) of heart muscle tissue.

The scientists investigated MI mortality trends as per sex and age in five age groups during a 12-year period from 1994 to 2006. The study population included 916,380 MI patients from the National Registry of Myocardial Infarction (NRMI) who had a confirmed diagnosis of MI......... Posted by: Daniel      Read more         Source

October 15, 2009, 5:42 PM CT

Cost Effectiveness of Blood Pressure Device

A study conducted by the University of Rochester Medical Center (URMC) demonstrates that, for certain patient populations, an experimental device that lowers blood pressure appears to be a cost effective therapy. The implantable device, called Rheos, is in advanced stages of testing for individuals with drug resistant hypertension.

The study - which appears this month in the Journal of Clinical High blood pressure - used data from two large population-based studies and compared the occurence rate of adverse health events such as stroke and heart attack for groups of individuals with and without the blood pressure lowering benefit of the device. Scientists then projected the health care costs linked to those events over a patient's lifetime. The results show that if Rheos continues to perform at a level consistent the initial findings in ongoing clinical trials, then the device is a cost effective way to control hypertension.

"Our goal was to determine whether or not the benefit of Rheos would offset the higher upfront costs," said Kate C. Young, Ph.D., MPH, an instructor in the departments of Surgery and Neurology at URMC and main author of the study. "What we found is that the device's cost effectiveness is dependent upon the degree to which it can reduce blood pressure and the starting point of the patient"......... Posted by: Daniel      Read more         Source

October 12, 2009, 7:19 AM CT

Mending broken hearts

By mimicking the way embryonic stem cells develop into heart muscle in a lab, Duke University bioengineers believe they have taken an important first step toward growing a living "heart patch" to repair heart tissue damaged by disease.

In a series of experiments using mouse embryonic stem cells, the bioengineers used a novel mold of their own design to fashion a three-dimensional "patch" made up of heart muscle cells, known as cardiomyocytes. The new tissue exhibited the two most important attributes of heart muscle cells - the ability to contract and to conduct electrical impulses. The mold looks much like a piece of Chex cereal in which scientists varied the shape and length of the pores to control the direction and orientation of the growing cells.

The scientists grew the cells in an environment much like that found in natural tissues. They encapsulated the cells within a gel composed of the blood-clotting protein fibrin, which provided mechanical support to the cells, allowing them to form a three-dimensional structure. They also observed that the cardiomyocytes flourished only in the presence of a class of "helper" cells known as cardiac fibroblasts, which comprise as much as 60 percent of all cells present in a human heart.

"If you tried to grow cardiomyocytes alone, they develop into an unorganized ball of cells," said Brian Liau, graduate student in biomedical engineering at Duke's Pratt School of Engineering. Liau, who works in the laboratory of assistant professor Nenad Bursac, presented the results of his latest experiments during the annual scientific sessions of the Biomedical Engineering Society in Pittsburgh......... Posted by: Daniel      Read more         Source