Navigation Links
Therapy sought to reduce major risk from minor bleeding that can follow stroke
Date:5/12/2014

AUGUSTA, Ga. Bleeding into the brain following a stroke doesn't have to be big to be bad, says a researcher exploring a therapy to eliminate the major risk of minor bleeding.

The main problem with a minor bleed is the Iron in the blood , which is essential to transporting oxygen to the brain and body, but can be lethal when it comes in direct contact with brain tissue, said Dr. Adviye Ergul, vascular physiologist at the Medical College of Georgia at Georgia Regents University.

"We need iron in our blood, but we don't want it in our brain," said Ergul, who recently received a $1.8 million grant from the National Institutes of Health to better understand how a relatively small amount of blood and iron are bad for the brain and whether an agent that mops up iron can help.

Her focus is diabetes, which puts patients at higher risk of stroke, bleeding, and poor recovery. As with the general population, people with diabetes are at greatest risk for a clot-based stroke that interrupts blood and oxygen supplies to the brain, much as a heart attack does to the heart.

But the damage diabetes does to blood vessels making existing vessels leaky and prompting proliferation of new, leaky ones also means these patients may subsequently experience bleeding from the miles of tiny blood vessels in their brain.

"Patients with diabetes are more likely to bleed into the brain following an ischemic stroke," Ergul said. "It happens spontaneously; it also happens with tPA." Tissue plasminogen activator, or tPA, is a clot-busting agent and the only currently approved medical therapy for stroke. Bleeding is a known risk of tPA that increases in diabetes.

"Patients with diabetes are some of the highest risk patients to bleed with tPA," Ergul said. In fact, while no such recommendations exists in the United States, in Europe, patients with prior stroke and diabetes are not given tPA when they have a recurrent stroke.

From observations in her animal models as well as humans, Ergul suspects many patients with diabetes who have a stroke likely could benefit from rapid removal of iron from the brain.

She is looking at the iron chelating agent, deferoxamine, which basically binds to iron so it becomes inactive and can be easily eliminated in the urine. Deferoxamine, already used clinically for iron overdoses and certain anemias, is under study for hemorrhagic stroke treatment. Hemorrhagic strokes, which are far less common than clot-based strokes and typically more lethal, result from major bleeding from some of the larger arteries in the brain. The rapid, resulting destruction is caused by a large amount of blood pushing brain tissue aside and up again the skull.

While the bleeding that follows a clot-based stroke likely doesn't produce sufficient volume to put that kind of pressure on the brain, the comparatively small amount of bleeding that occurs still exposes brain cells to iron.

"Iron not only kills neurons, we think it also kills endothelial cells in the brain and it affects how endothelial cells can repair themselves." Ergul said. Endothelial cells, which line all blood vessels, comprise the majority of the tiny capillaries which have only one layer of contractile cells on top. Larger vessels have multiple layers of smooth muscle cells.

Similar to what happens with aging, the tiny vessels don't relax or regenerate normally in diabetes. Ergul has evidence that iron, which shouldn't be in brain tissue, also stimulates inflammation as part of an immune response, which further increases the leakiness of the capillaries.

While attempts to stop bleeding in a hemorrhagic stroke are often unsuccessful, essentially nothing is done for bleeding following a clot-based stroke, Ergul said. In fact, clinicians may view the bleeding as an indicator that blood flow has been reestablished to the struggling tissue.

In her stroke models, she is using the chelation agent daily for two weeks alone or after administering tPA, to see how the drugs interact and look at levels of recovery. Within 14 days, normal animals would have mostly recovered from the stroke. She's also examining further how stroke recovery is impacted by diabetes.

While new blood vessels are a good thing in the heart or legs, "We are making the argument that making new blood vessels is not always a good thing," Ergul said. "We need to find ways to stimulate stable and functional new vessels." Ergul notes that the abnormal blood vessel proliferation that occurs in the brain is very similar to the sight-destroying vessels that proliferate in the eye in diabetic retinopathy.

More than 7 percent of Americans have diabetes which puts them at a two- to six-fold increased risk of an ischemic, or clot-based, stroke and poor recovery. Arteries feed arterioles which feed the 400 miles of capillaries in the brain, which feed back into the venous system.


'/>"/>

Contact: Toni Baker
tbaker@gru.edu
706-721-4421
Medical College of Georgia at Georgia Regents University
Source:Eurekalert  

Related medicine news :

1. KRAS gene mutation and amplification status affects sensitivity to antifolate therapy
2. Antibody therapy prevents gastrointestinal damage following radiation exposure in mice
3. Chemotherapy proves life-saving for some leukemia patients who fail induction therapy
4. Immunotherapy for elderly cancer patients finds new promise in drug combination
5. Therapy exploits addiction of leukemia cells
6. Intensity Modulated Radiation Therapy optimal for localized prostate cancer
7. Adding drug to standard chemotherapy provides no survival benefit for older lung cancer patients
8. Study Casts Doubt on Value of Pricey Prostate Cancer Therapy
9. 19th century therapy for Parkinsons disease may help patients today
10. New Psoriasis Drugs Not Much Better Than Standard Therapy, Study Finds
11. Xenotransplantation as a therapy for type 1 diabetes
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Therapy sought to reduce major risk from minor bleeding that can follow stroke
(Date:6/25/2016)... CA (PRWEB) , ... June 25, 2016 , ... As ... with Magna Cum Laude and his M.D from the David Geffen School of Medicine ... and returned to Los Angeles to complete his fellowship in hematology/oncology at the UCLA-Olive ...
(Date:6/24/2016)... ... 24, 2016 , ... Those who have experienced traumatic events may suffer from ... avenues, such as drug or alcohol abuse, as a coping mechanism. To avoid this ... coping following a traumatic event. , Trauma sufferers tend to feel a range of ...
(Date:6/24/2016)... ... June 24, 2016 , ... Dr. Amanda Cheng, an ... Dr. Cheng has extensive experience with all areas of orthodontics, including robotic Suresmile ... orthodontics. , Micro-osteoperforation is a revolutionary adjunct to orthodontic treatment. It can ...
(Date:6/24/2016)... ... June 24, 2016 , ... The Haute Beauty Network, ... M. Weintraub as a prominent plastic surgeon and the network’s newest partner. ... the most handsome men, look naturally attractive. Plastic surgery should be invisible.” He ...
(Date:6/24/2016)... MD (PRWEB) , ... June 24, 2016 , ... ... protocols for human induced pluripotent stem (iPS) cells and other difficult to transfect ... G9™ Cloning Medium. The PluriQ™ G9™ Gene Editing System is a ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... NAMUR , Belgium , ...  (NYSE MKT: VNRX), today announced the appointment of ... Board of Directors as a Non-Executive Director, effective ... the Company,s Audit, Compensation and Nominations and Governance ... Board, Dr. Futcher will provide independent expertise and ...
(Date:6/23/2016)... Research and Markets has announced the ... to 2022" report to their offering. ... patients with kidney failure, it replaces the function of kidneys ... blood and thus the treatment helps to keep the patient ... Increasing number of ESRD patients & substantial ...
(Date:6/23/2016)... June 23, 2016  In a startling report released today, ... residents by lacking a comprehensive, proven plan to eliminate prescription opioid ... ranking of how states are tackling the worst drug crisis in ... states – Kentucky , New Mexico ... . Of the 28 failing states, three – ...
Breaking Medicine Technology: