From Berlin to Yerkes

Yerkes immunologist Guido Silvestri and colleagues have a paper in PLOS Pathogens shedding light on the still singular example of Timothy Brown, aka "the Berlin patient", the only human cured of HIV.

HIV vaccine insight via Rwanda

Rebuilding a shattered society is compatible with HIV vaccine research

Cardiac cell therapy: three papers at a glance

Cardiac cell therapy sounds like a promising idea: use the patients’ own cells to enhance healing or even regenerate the damaged heart muscle. Doctors have taken up the promise, testing it in clinical trials involving thousands of patients. But a basic problem facing the field is this: naked cells don’t appear to stay in the heart or stay alive for long enough to provide a sustained benefit. Three labs at Emory have published papers in the last year addressing this problem. All describe some kind of supportive biomaterials, consisting of capsules or a gel, which help cells stay put and stay alive, in experiments where recovery from a heart attack is modeled in rodents. The most recent comes from cardiologist Young-sup Yoon and colleagues, in ACS Nano. The first author is Kiwon Ban, a senior postdoc in Yoon’s laboratory. Ban and his team use self-assembling peptides, developed in collaboration with biomaterials engineer Ho-wook Jun at UAB (see figure). The peptides form a gel that both physically keeps cardiac muscle cells in the heart and eases their integration into the heart tissue over a period of weeks. As Katie Bourzac explains in Chemical & Engineering News: One peptide acts like a natural protein that adheres to cells and promotes cell survival. The second peptide is readily broken down by a protease. The team designed the gel so that when it is implanted, it begins to degrade a bit, allowing cells from the body to migrate in. Eventually the gel should disintegrate completely as the heart tissue builds its own extracellular matrix. This particular gel has already performed well as a support for other kinds of cells grown from stem cells, including pancreatic and muscle cells. We thought it may be useful to readers to be able to compare and contrast these papers in chart form.  Levit et al. JAHA 2013 (blog post) Boopathy et al Biomaterials 2014 (blog post) Ban et al ACS Nano 2014 (discussed here) Source of cells Mesenchymal stem cells Cardiac progenitor cells, derived from cardiac tissue Differentiated cardiac muscle cells, derived from embryonic stem cells Supportive technology Alginate encapsulation Self-assembling peptides with Notch ligand Self-assembling peptides with RGDS (fibronectin ligand), MMP degradable Experimental model Immunodeficient rat myocardial infarction Rat myocardial infarction Immunodeficient mouse myocardial infarction How therapeutic effect assessed Cell retention, ejection fraction, scar size, new blood vessels Retention in heart, ejection fraction, scar size Retention in heart, ejection fraction, scar size Other distinctive aspects Capsules were combined with a hydrogel patch, which dissolves in 1 week Gel composition can modulate cell behavior Only gel allowed cells to last >3 weeks + engraft into heart The main differences are apparent in two areas: the supportive material and in the source of cells. With mesenchymal stem cells, the paracrine effect -- providing growth and survival factors -- is the name of the game, not becoming part of the cardiac tissue permanently. Mesenchymal stem cells, potentially available in the clinic through tapping patients’ bone marrow, are not going to be able to engraft into the heart because they can't become cardiac muscle, or new blood vessels. But with cardiac progenitor cells or differentiated cardiac muscle cells, engraftment is researchers' goal.  Cardiac progenitor cells can be purified from cardiac tissue biopsies and then grown in culture. Doctors could obtain differentiated cardiac muscle cells by generating induced pluripotent stem cells from patients’ skin or blood cells, and then differentiating those cells into cardiac muscle cells (a process Yoon, Ban and Gang Bao's lab at Georgia Tech have also described in a 2013 paper).

cholesterol

Evaluating a different way to measure LDL

What is the most important measurement of cholesterol or lipids in the blood, when it comes to cardiovascular disease risk? LDL-C [low density lipoprotein cholesterol], is often called “bad cholesterol” because it is linked to atherosclerosis, but the landscape is always shifting. Even as cardiologists across the country get used to the new AHA/ACC guidelines, which call for changes in how physicians and patients view LDL-C, new research is focusing attention on other related markers. For example, a recent pair of studies in the New England Journal of Medicine identify gene mutations that lower both triglycerides and heart disease risk, suggesting that drugs that target that gene pathway could be beneficial. A new paper in Atherosclerosis, coauthored by Emory’s Terry Jacobson, looks at LDL-P, a different way of looking at LDL that has been proposed to be a better measure of cardiovascular disease risk. Jacobson is director of the Office of Health Promotion and Disease Prevention at Grady Health Systems. Read more

Posted on by Quinn Eastman in Heart Leave a comment

A good reason to enjoy a little Valentine’s Day chocolate

From the Clinic to You

BY CHERYL WILLIAMS, RD, LD

If you’re looking for an excuse to indulge in the yummy chocolate you get this Valentine’s Day, research suggests it may not be so bad for you.

A number of studies, conducted over the last decade have associated cocoa and dark chocolate consumption with heart health benefits. These benefits come from cocoa, derived from the cacao plant, which is rich in flavonoids (cocoa flavanols to be exact). Flavonoids are antioxidants also found in berries, grapes, tea, and apples. As a whole, antioxidants prevent cellular damage and inflammation which are two major mechanisms involved in the development of heart disease.

So what does the research say?

A study published in the American Journal of Clinical Nutrition found that high-flavanol dark chocolate reduced bad cholesterol (LDL) oxidation and increased good cholesterol (HDL) levels. LDL oxidation promotes the development of plaque and hardening of the coronary arteries, thus lessening oxidation could help to prevent heart disease.

A Harvard research study found that flavanol-rich cocoa induced nitric-oxide production, which causes blood vessels to relax and expand, thus improving blood flow. Improved coronary vasodilation could potentially lower the risk of a cardiovascular event.

In a double-blind randomized Circulation study flavonoid-rich dark chocolate (containing 70% cocoa) reduced serum oxidative stress and decreased platelet activity (clumping) in heart transplant recipients. This favorable impact on vascular and platelet function is relevant because vascular dysfunction and platelet activation (adhesion upon damaged cell wall) are the basis of atherothrombosis (blood clotting) and coronary artery disease.

How can you reap chocolate’s potential benefits?

Not all cocoa products and/or chocolates are created equal. Milk chocolate, for example, is not rich in flavanols (contains only 10-20% cocoa solids) and white chocolate contains none at all. In addition, some cocoa products and chocolates are processed with alkali, which can destroy flavanols.

Follow these tips for heart healthy chocolate consumption:

  • Avoid cocoa products processed with alkali (dutched) as seen in the ingredient list
  • Choose dark chocolate with at least 70% cocoa
  • Enjoy 100% unsweetened non-dutched cocoa (great for hot chocolate!)

Also, remember that chocolate is not a health food, as it is high in calories, fat and added sugar. Thus, make room for dark chocolate by cutting extra calories elsewhere in your diet. Additionally, stick to small amounts (e.g. 1 ounce) and do not eat in place of plant-based whole foods such as vegetables and fruits.

Cheryl Williams is a registered dietitian at the Emory Heart & Vascular Center. She provides nutrition therapy, wellness coaching, monthly nutrition seminars and healthy cooking demonstrations working with the Emory HeartWise Cardiac Risk Reduction Program.

Posted on by Jennifer Johnson in Uncategorized 2 Comments

Cholesterol levels improve with nut consumption

Improvements in blood cholesterol levels are linked with eating nuts, according to this week’s Archives of Internal Medicine.

Nuts are good for your heart

Authors writing in the journal say that dietary interventions to lower blood cholesterol concentrations and to modify blood lipoprotein levels are the cornerstone of prevention and treatment plans for coronary heart disease.

Nuts are rich in plant proteins, fats (especially unsaturated fatty acids), dietary fiber, minerals, vitamins and other compounds, such as antioxidants and phytoesterols. The contents of nuts are a focus because of the potential to reduce coronary heart disease risk and to lower blood lipid – fat and cholesterol – levels.

Emory University’s Cheryl Williams, RD, LD, clinical nutritionist, Emory Heart & Vascular Center, Emory HeartWise Cardiac Risk Reduction Program, says nuts are among the heart healthiest whole foods as they provide a variety of health promoting compounds such as dietary fiber, vitamins (vitamin E), minerals (selenium), antioxidants and phytoesterols.

While most of the calories provided from nuts come from fat, notes Williams, it is mostly unsaturated fats (mono and polyunsaturated), which have been shown to help lower elevated serum cholesterol, and to some extent triglyceride levels (via omega 3 fatty acids provided from walnuts).

Read more

Posted on by Jennifer Johnson in Uncategorized Leave a comment

National Cholesterol Month: Check your numbers

Emory’s Cheryl Williams, RD, LD, clinical nutritionist for the Emory Heart & Vascular Center and Emory HeartWise Cardiac Risk Reduction Program, says you should make it a priority to know your cholesterol levels and learn how what you eat can impact cholesterol and your heart’s health.Williams heart

Since diets high in saturated fat and trans fat have been linked to chronic disease, specifically, heart disease, this knowledge could save your life.

During National Cholesterol Month Williams notes in her blog for the Atlanta Journal-Constitution’s “Doctor Is In” that eating too many fatty foods – especially those high in saturated fat and trans fat – is the primary cause of high cholesterol. Thin, active people may not be aware of how much bad fat they consume, she says.

According to Williams, “Saturated fats are derived primarily from animal products and are known to raise cholesterol levels. They are found in common foods like butter, cheese, whole milk, pork and red meat. Lower-fat versions of these foods usually contain saturated fats, but typically in smaller quantities than the regular versions. Certain plant oils, like palm and coconut oils, are another source of saturated fats. You may not use these oils when you cook, but they are often added to commercially baked foods, such as cookies, cakes, doughnuts and pies.

Even more detrimental to cholesterol levels are trans fats, artificially created during food processing when liquid oils are converted into solid fats — a process called hydrogenation. Many fried restaurant foods and commercially baked goods contain trans fats, as well as vegetable shortening and stick margarine. Read labels and avoid foods that contain partially or fully hydrogenated oils.”

For more tips from Williams about managing for healthy cholesterol levels, visit ajc.com. To learn more about heart disease from Laurence Sperling MD, director of the Emory HeartWise Cardiac Risk Reduction Program, watch videos on health.com.

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