Monthly Archives: August 2013

Stem cells help offset brain damage from stroke

bone marrow stem cells Cognitive deficits following ischemic stroke are common and debilitating, even in the relatively few patients who are treated expeditiously so that clots are removed or dissolved rapidly and cerebral blood flow restored.

A new study in Restorative Neurology and Neuroscience demonstrates that intracerebral injection of bone-marrow-derived mesenchymal stem cells (BSCs) reduces cognitive deficits produced by temporary occlusion of cerebral blood vessels in a rat model of stroke, suggesting that BSCs may offer a new approach for reducing post-stroke cognitive dysfunction.

According to the American Heart Association, almost half of ischemic stroke survivors older than 65 years of age experience cognitive deficits, contributing to functional impairments, dependence, and increased mortality. The incidence of cognitive deficits triples after stroke and about one quarter of cognitively impaired stroke patients’ progress to dementia. For these reasons, “there is an underlying need for restorative therapies,” says lead investigator Gary L. Dunbar, PhD, of the Field Neurosciences Institute Laboratory for Restorative Neurology, and Director of the Central Michigan University Program in Neuroscience.

In order to see whether mesenchymal stem cells derived from bone marrow could attenuate or prevent cognitive problems following a stroke-like ischemic event, the investigators mimicked stroke in rats by injecting the hormone endothelin-1 (ET-1) directly into the brain in order to constrict nearby blood vessels and block blood flow temporarily. Control animals underwent similar surgery but were injected with saline, not ET-1.

Seven days after the “stroke”, some of the rats received intrastriatal injections of BSC, while others received control injections. Cognition was evaluated using a spatial operant reversal task (SORT), in which the animals were trained to press a lever a certain number of times when it was illuminated to receive a food reward.

The investigators found that animals that underwent a stroke but were then injected with BSC made significantly fewer incorrect lever presses than stroke rats who received control injections. In fact, the BSC-treated stroke animals performed as well as those who did not have a stroke. “Importantly, there were no significant between-group differences in the total number of lever presses, indicating the deficits observed were cognitive, rather than motor in nature,” said Dr. Dunbar. No differences were observed in infarct size between the BMMSC-treated and control groups.

The authors emphasize that the BMMSCs were effective even when transplanted seven days after the induced stroke, a finding that offers hope to patients who may not present for treatment immediately. The authors suggest that BMMSCs may work by creating a microenvironment that provides trophic support to remaining viable cells, perhaps by releasing substances such as brain-derived neurotrophic factor (BDNF).
Source: ScienceBlog, http://www.scienceblog.com

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Special type of stem cells could help heal hearts

About 5.8 million Americans have heart failure, a condition that occurs when the heart can no longer pump enough blood to meet the body’s needs.

Now, researchers say a special type of stem cell may be the key to repairing these hearts. Golf has always been a big part of Ron Signorelli’s life.

“I started when I was ten,” Ron said.  Painted heart

However, Ron’s congestive heart failure was keeping him away from his favorite pastime.

“I was in the hospital over 20 times,” Ron said.

Ron’s heart pumped only 15 percent of blood. He needed help fast.

“There’s a large number of patients out there that are really in this situation where they’re gone past what normal medical therapy can do, but yet they’re not sick enough or don’t qualify for a heart transplant,” Timothy D. Henry, MD, Director of Research Minneapolis Heart Institute Foundation said.

Now, a new approach can help patients like Ron. First, doctors extract bone marrow stem cells from the patient. Then, they grow the cells to enhance their healing ability. Those cells are then injected directly into the patient’s heart.

“Our hopes are we improve the quality of their life, as well as the length of their life,” Dr. Henry said.

In the first clinical trial, the treatment was safe, repaired damaged heart muscles, and even appeared to reverse some heart failure symptoms. Ron had 12 injections and hasn’t been to the hospital since.

“I certainly feel good. I’m a very active person,” Ron said. Now, nothing stops his stride. “When the weather is nice, I’ll play three, four times a week,” Ron explained.

Researchers are planning enrollment for the second phase of this trial at about 30-sites across the U.S. Once the results are assessed, the treatment will likely be more widely available. This therapy would not replace a heart transplant, but may delay or prevent the need for transplantation in the future.

Source: Margot Kim, http://www.abclocal.go.com