Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Method to prevent hemorrhagic complications of thrombolytic therapy of blood clots is discovered

04.07.2007
A novel method to prevent hemorrhagic complications of thrombolytic therapy of blood clots is discovered.

Blood clot dissolution by thrombolytic therapy is an approved, safe and efficaceous therapy of acute ischemic stroke. It is in routine use world-wide, and prevents individuals from stroke-related long-term disability. Many safe therapy forms, however, are often associated with hazards, and therefore indications for therapy must be weighed on an individual basis.

In stroke thrombolysis, it is the risk of perithrombolytic hemorrhage formation and expansive brain edema that are most feared complications, and may preclude from administering the therapy. Even after proper precautions, perithrombolytic hemorrhages occur in 6 to 10 % of treated patients. Therefore, experimental research is needed to clarify the mechanisms leading to these complications.

The now reported study led by Dr. Perttu J. Lindsberg from the Helsinki University Central Hospital investigated thrombolytics-related brain hemorrhage formation in an experimental stroke model in rats. It found that, in addition to the clot lysing effect, the drug used for this purpose, alteplase (recombinant tissue plasminogen activator) also possesses proinflammatory properties and activates and degranulates mast cells, a kind of tissue-based immune cell. On degranulation, mast cells release potent enzymes that cleave proteins (eg, chymase, tryptase, and metalloproteases) in the vessel wall. The result is increased vascular permeability, which can lead to hazardous brain edema and potentially to frank brain hemorrhage formation. A pharmacological mast cell stabilizer, cromoglycate, was administered before alteplase, and it reduced these detrimental effects significantly and led to improved neurological outcome and reduced mortality.

The amount of brain hemorrhage was reduced by 97% at 3 hours, by 76% at 6 hours, and by 96% after 24 hours of follow-up. Ischemic brain edema was reduced by 80% at 3 hours, by 55% at 6 hours and by 85% after 24 hours of follow-up. The mortality in control group was 29%, 64% in alteplase group, and 0% in a group treated with a combination of alteplase and cromoglycate. kromoglikaatti+alteplaasiryhmässä 0%). Furthermore, genetically engineered animals were used which lacked mast cells, and they showed minimal brain edema and alteplase-related hemorrhage formation. They also had improved neurological outcome and mortality compared with wild-type littermates. In addition to proteolytic enzymes, mast cells release vasodilators such as histamine as well as heparin (s.c. “blood thinning” anticoagulant drug), which may locally prevent blood coagulation, predispose to bleeding and edema formation and ultimately lead to hazardous expansion of hemorrhagic and edematous brain events. The intracranial space is tight and does not allow expansion of its tissue content without harmful and potentially fatal consequences.

This study revealed a novel proinflammatory cellular mechanism related to an every-day dilemma in routine patient care that may provide a novel pharmacological target if confirmed in the clinical setting. At best, mast cell stabilization could eventually be applied as an adjuvant to thrombolysis.

Perttu Lindsberg | EurekAlert!
Further information:
http://www.elisanet.fi

More articles from Health and Medicine:

nachricht World first: Massive thrombosis removed during early pregnancy
20.07.2017 | Universitätsspital Bern

nachricht Therapy of preterm birth in sight?
19.07.2017 | Universitätsspital Bern

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>