New Imaging Approach Reveals Lymph System in Brain

Considering all the recent advances in mapping the complex circuitry of the human brain, you’d think we’d know all there is to know about the brain’s basic anatomy. That’s what makes the finding that I’m about to share with you so remarkable. Contrary to what I learned in medical school, the body’s lymphatic system extends to the brain—a discovery that could revolutionize our understanding of many brain disorders, from Alzheimer’s disease to multiple sclerosis (MS).

Researchers from the National Institute of Neurological Disorders and Stroke (NINDS), the National Cancer Institute (NCI), and the University of Virginia, Charlottesville made this discovery by using a special MRI technique to scan the brains of healthy human volunteers [1]. As you see in this 3D video created from scans of a 47-year-old woman, the brain—just like the neck, chest, limbs, and other parts of the body—possesses a network of lymphatic vessels (green) that serves as a highway to circulate key immune cells and return metabolic waste products to the bloodstream.

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Creative Minds: Exploring the Role of Immunity in Hypertension

Meena Madhur

Meena Madhur / Credit: John Russell

If Meena Madhur is correct, people with hypertension will one day pay as much attention to their immune cell profiles as their blood pressure readings. A physician-researcher at Vanderbilt University School of Medicine, Nashville, Madhur is one of a growing number of scientists who thinks the immune system contributes to—or perhaps even triggers—hypertension, which increases the risk of stroke, heart disease, kidney disease, and other serious health problems.

About one of every three adult Americans currently have hypertension, yet a surprising number don’t know they have it and less than half have their high blood pressure under control—leading many health experts to refer to the condition as a “silent killer”[1,2]. For many folks, blood pressure control can be achieved through lifestyle changes, such as losing weight, exercising, limiting salt intake, and taking blood pressure medicines prescribed by their health-care provider. Unfortunately, such measures don’t work for everyone, and some people continue to suffer damage to their kidneys and blood vessels from poorly controlled hypertension.

Madhur wants to know whether the immune system might be playing a role, and whether this might hold some clues for developing new, more targeted ways of treating high blood pressure. To get such answers, this practicing cardiologist will use her 2016 NIH Director’s New Innovator Award to conduct sophisticated, single-cell analyses of the immune systems of people with and without hypertension. Her goal is to produce the most comprehensive catalog to date of which human immune cells might be involved in hypertension.

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Clot Removal: Impressive Results for Stent Retrievers in Acute Stroke

Schematic of clot retriever

Caption: Schematic of how the clot retriever used in the reported trials is opened inside a blood vessel to surround a clot that is blocking blood flow. Once caught by the stent, the entire apparatus with the clot is removed from the body out a small puncture in the femoral artery at the groin.
Credit: Covidien

Despite the recent progress we’ve made in preventing stroke by such steps as controlling weight, lowering blood pressure, and stopping smoking, nearly 700,000 Americans suffer clot-induced, or ischemic, strokes every year [1]. So, I’m very pleased to report that, thanks to years of rigorous research and technological development, we’ve turned a major corner in the emergency treatment of this leading cause of death and disability.

The most severe strokes—those that can cause lifelong loss of independent function—are often due to blood clots that suddenly enter and block one of the main arteries supplying blood flow to the brain. No less than four large, randomized clinical trials recently reported results showing, for the first time, that using catheters to remove large clots from cerebral arteries can restore blood flow and halt further damage to the brains of patients with acute strokes. In fact, the stent-based retrievers and other mechanical approaches used to remove stroke-causing clots proved so effective, that three of the four trials were stopped early, allowing the results to be made swiftly available to medical professionals and the public.

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Rare Disease Sleuths Uncover New Clues to Stroke

Drawing of a brain section with an inflamed blood vessel

Caption: A variation in the gene that codes for a key blood vessel enzyme makes children prone to fevers, rash, and strokes.
Credit: Jonathan Bailey, National Human Genome Research Institute, NIH

A medical mystery that began when a 3-year-old girl came to the NIH Clinical Center here in Bethesda, MD, a decade ago has just been solved. The findings not only promise to help children suffering from a devastating rare disease, but to advance our overall understanding of stroke and other blood vessel disorders.

When researchers first met the little girl, they were baffled. She had a most unusual—and unexplained—constellation of symptoms: recurring fevers, rashes, and strokes, which, sadly, had left her severely disabled. Researchers thought the cause probably wasn’t genetic, because none of the girl’s family members were affected, plus they hadn’t seen other children with similar problems. While they searched for clues, they treated the girl with immunosuppressive drugs to reduce blood vessel inflammation and thereby lower the chance of future strokes.

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MicroRNA Research Takes Aim at Cholesterol

Illustration of artery partially blocked by a cholesterol plaque

Caption: Illustration of artery partially blocked by a cholesterol plaque.

If you’re concerned about your cardiovascular health, you’re probably familiar with “good” and “bad” cholesterol: high-density lipoprotein (HDL) and its evil counterpart, low-density lipoprotein (LDL). Too much LDL floating around in your blood causes problems by sticking to the artery walls, narrowing the passage and raising risk of a stroke or heart attack. Statins work to lower LDL. HDL, on the other hand, cruises through your arteries scavenging excess cholesterol and returning it to the liver, where it’s broken down.

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