Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Green Mamba Snake Venom Hormone May Cause “Second Stroke”

02.08.2004


A Mayo Clinic research team is focusing on a hormone previously identified in the venom of the green mamba snake for the role it may play in a dangerous blood vessel narrowing in stroke patients that can lead to a second stroke, reduced blood flow and brain damage.



Called “cerebral vasospasm,” this common complication of stroke occurs in approximately one-third of patients who experience a ruptured brain blood vessel. Its cause is not known. By discovering a possible role for this hormone, Mayo Clinic researchers are establishing the conceptual foundations for a new treatment for cerebral vasospasm. Their report occurs in the current issue of Neurosurgery.

In their pilot study, the Mayo Clinic researchers discovered that a specific pair of amino acids -- a “peptide” known as DNP -- was significantly elevated (29 percent) in aneurysm patients who went on to develop complications of cerebral vasospasm. Among the six patients in the study who were followed for seven days after their initial aneurysm ruptured, four patients showed evidence of cerebral vasospasm -- a much higher frequency than the 30 percent figure commonly cited. Of the four patients who had cerebral vasospasm, three -- 75 percent -- had increased DNP levels.


The study was a pilot study, which means it was kept deliberately small to test the validity of the idea. Though the sample of patients was small because it is a pilot study, researchers say the results are so promising they justify a larger, case-controlled formal study. They want to pursue the possibility that DNP may one day provide a target for new therapies to stop cerebral vasospasm. Says Mayo Clinic neurologist Eelco Wijdicks, M.D., lead investigator, “If these results hold up in larger investigations, it could help us develop a very valuable specific therapeutic tool that would greatly reduce a major disabling complication of our patients.”

About Subarachnoid Aneurysm and Cerebral Vasospasm

The pilot study patients all suffered a spontaneous rupture of a brain blood vessel known as an “aneurysm” that bled into the space between the brain and the middle membrane. This condition is known as a “subarachnoid hemorrhage” and is a type of stroke. It occurs in an estimated one out of 10,000 people, and it is most common in people 20 to 60 years old. About 30 percent of patients with aneurysm-caused subarachnoid hemorrhage develop cerebral vasospasm three to seven days later. Of those who develop cerebral vasospasm, about one-fourth experience a second stroke and are therefore at risk for brain damage and other complications.

Background

The Mayo Clinic researchers describe a possible role for a peptide known as Dendroaspis natriuretic peptide (DNP). A peptide is a pair of amino acids bound together in a specific way. Peptides make up proteins, and proteins do all the messaging and signaling work in the body, such as turning genes on or off. Knowing the nature of a peptide provides researchers with a possible way to manipulate proteins, and thereby control cellular processes.

DNP belongs to a family known as natriuretic peptides. They are naturally-occurring substances that influence smooth muscle contraction. Smooth muscle tissue lines the blood vessels. DNP also is found in the venom of the green mamba snake, as well as in human blood plasma and heart muscle.

Several investigations in humans have established that peptides in this family play a role in maintaining fluid and salt stores. Many patients lose massive amounts of fluids and sodium after this type of hemorrhage. And because they already have poor blood flow due to vasospasm, a second stroke can occur. Says Dr. Wijdicks, “Maintaining a good fluid balance and adding fluid when needed is essential to recovery. And understanding why and how these peptides work or disturb the status quo is very important to improving the outcome for patients.”

The Mayo Clinic investigation is the first to look at DNP in cases of ruptured brain aneurysm and cerebral vasospasm and to document its elevated levels. However, other investigators have found elevated DNP levels in human plasma and heart muscle of patients who have congestive heart failure.

In addition to Dr. Wijdicks, other members of the Mayo Clinic research team include Vini Khurana, M.D.; Denise Heublein; Robyn McClelland; Fredric Meyer, M.D.; David Piepgras, M.D.; and John Burnett Jr., M.D. Mayo Foundation supported their research.

| newswise
Further information:
http://www.mayo.edu
http://www.neurosurgery-online.com

More articles from Health and Medicine:

nachricht Organ-on-a-chip mimics heart's biomechanical properties
23.02.2017 | Vanderbilt University

nachricht Researchers identify cause of hereditary skeletal muscle disorder
22.02.2017 | Klinikum der Universität München

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>