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 NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures
17.11.2017 | National Institute of Standards and Technology (NIST)

nachricht High speed video recording precisely measures blood cell velocity
15.11.2017 | ITMO University

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: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Antarctic landscape insights keep ice loss forecasts on the radar

20.11.2017 | Earth Sciences

Filling the gap: High-latitude volcanic eruptions also have global impact

20.11.2017 | Earth Sciences

Water world

20.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>