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 Routing gene therapy directly into the brain
07.12.2017 | Boston Children's Hospital

nachricht New Hope for Cancer Therapies: Targeted Monitoring may help Improve Tumor Treatment
01.12.2017 | Berliner Institut für Gesundheitsforschung / Berlin Institute of Health (BIH)

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: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>