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 Study tracks inner workings of the brain with new biosensor
16.08.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Foods of the future
15.08.2018 | Georg-August-Universität Göttingen

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: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Quantum material is promising 'ion conductor' for research, new technologies

17.08.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>