Microbubbles improve myocardial remodelling after infarction

Researchers at Bonn University Hospital demonstrate that ultrasound can ameliorate the sequelae of a myocardial infarction

2013-02-21

(Press-News.org) Scientists from the Bonn University Hospital successfully tested a method in mice allowing the morphological and functional sequelae of a myocardial infarction to be reduced. Tiny gas bubbles are made to oscillate within the heart via focused ultrasound - this improves microcirculation and decreases the size of the scar tissue. The results show that the mice, following myocardial infarction, have improved cardiac output as a result of this method, as compared to untreated animals. The study is now being presented in the professional journal PLOS ONE.

Every year in Germany, approximately 280,000 people suffer a myocardial infarction; more than 52,000 die as a result. Due to an occluded vessel, parts of the heart muscle no longer have sufficient circulation and the tissue dies off. These regions are not replaced by new heart muscle cells but instead by scar tissue – this generally causes the pump function of the heart to decrease following an infarction. Scientists from the Bonn University Hospital have now successfully tested a new method on mice with which scar tissue can be reduced and cardiac output increased.

Microbubbles are made to oscillate within the heart

"There are attempts to treat the scar tissue with gene therapy or stem cells - by contrast, we have chosen a physical approach to treatment," reports Adj. Professor Dr. med. Alexander Ghanem from the Department of Cardiology of the Bonn University Hospital. The researchers injected a total of 17 mice which had previously had a myocardial infarction with microscopically small, gas-filled bubbles in the bloodstream. Once the microbubbles reached the heart, they were made to vibrate there using focused ultrasound. "Through this mechanical stimulation, the circulation of the area of the infarction is improved - and the scar shrinks," says the cardiac specialist.

Treated animals demonstrate ameliorated post-infarction remodelling

The scientists compared the results of the mice treated with the microbubbles to those of a control group. Two weeks after the myocardial infarction, there was expected worsening of heart function in the control group due to the maturing of the scar tissue. In contrast, the mice treated with the microbubbles did not develop any cardiac insufficiency. Jonas Dörner, the first author of the study, summarizes the results: "The pumping function was significantly better in the treated animals as compared to the control group; there was also a significantly smaller amount of decayed heart muscle tissue." Along with the Department of Cardiology, the Departments of Cardiac Surgery and Anesthesiology and the Institute of Physiology took part in the investigations.

Ultrasound treatment stimulates growth hormones

The scientists sought the causes of the positive treatment success which is, however, unexplained to date. Following ultrasound treatment of the mice, it was demonstrated that the amount of the body's own growth hormones significantly increased in the heart. "This is evidently the reason why the scar formation decreased as a result of the oscillating microbubbles," says Dr. Ghanem. The scientists now hope that humans will also be able to eventually be treated with the microbubble-ultrasound method, however further investigations are still needed. "Potentially, all patients who have had an acute myocardial infarction are eligible for this follow-up treatment," explains the cardiologist of the Bonn University Hospital. Interestingly, microbubbles are already used as a diagnostic contrast agent.

Patent for novel ultrasound method filed

The study, conducted with support from the BONFOR funding program of the Medical Faculty of Bonn University and the German Heart Foundation [Deutsche Herzstiftung e.V.], gave rise to a patent application. "Together with the company Philips Medical, we developed a novel ultrasonic probe which enables a standardized impulse discharge in the heart," reports the cardiologist. The special feature is that two ultrasound sources linked together are contained in one hybrid ultrasonic probe: one with low frequency for the focused stimulation of the microbubbles in the target organ and one with higher frequency for imaging. In this way, it can be very precisely determined where the scar tissue and the microbubbles are located. "This study demonstrates again that university research inspires technological developments in medicine," says Dr. Ghanem.

### Publication: Ultrasound-mediated stimulation of microbubbles after acute myocardial infarction and reperfusion ameliorates left-ventricular remodelling in mice via improvement of borderzone vascularisation, PLOS ONE, DOI: 10.1371/journal.pone.0056841, Internet: Internet: http://dx.plos.org/10.1371/journal.pone.0056841

Contact information:

Adj. Professor Dr. med. Alexander Ghanem
Department of Cardiology
Bonn University Hospital
Tel. +49 228 28715507
E-Mail: ghanem@uni-bonn.de END

ELSE PRESS RELEASES FROM THIS DATE:

Inhaled betadine leads to rare complication

2013-02-21

Philadelphia, Pa. (February 21, 2013) - A routine step in preparing for cleft palate surgery in a child led to an unusual—but not unprecedented—case of lung inflammation (pneumonitis), according to a report in the The Journal of Craniofacial Surgery. The journal, edited by Mutaz B. Habal, MD, FRCSC, is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health. The complication resulted from accidental inhalation of povidone-iodine (PI), or Betadine—an antiseptic widely used before surgery. The rare complication led to new surgical "prep" steps to reduce ...

Human heart development slower than other mammals

2013-02-21

The walls of the human heart are a disorganised jumble of tissue until relatively late in pregnancy, despite having the shape of a fully functioning heart, according to a pioneering study. Experts from the University of Sheffield's Medical School collaborated on research to create the first comprehensive model of human heart development using observations of living foetal hearts. The results showed surprising differences from existing animal models. Although scientists saw four clearly defined chambers in the foetal heart from the eighth week of pregnancy, they did ...

The age from when children can hop on one leg

2013-02-21

This press release is available in German. Motor development in children under five years of age can now be tested reliably: Together with colleagues from Lausanne, researchers from the University Children's Hospital Zurich and the University of Zurich have determined normative data for different exercises such as hopping or running. This enables parents and experts to gage the motor skills of young children for the first time objectively and thus identify abnormalities at an early stage. My child still can't stand on one leg or walk down the stairs in alternating ...

Scientists unveil secrets of important natural antibiotic

2013-02-21

An international team of scientists has discovered how an important natural antibiotic called dermcidin, produced by our skin when we sweat, is a highly efficient tool to fight tuberculosis germs and other dangerous bugs. Their results could contribute to the development of new antibiotics that control multi-resistant bacteria. Scientists have uncovered the atomic structure of the compound, enabling them to pinpoint for the first time what makes dermcidin such an efficient weapon in the battle against dangerous bugs. Although about 1700 types of these natural antibiotics ...

In rich and poor nations, giving makes people feel better than getting, research finds

2013-02-21

WASHINGTON - Feeling good about spending money on someone else rather than for personal benefit may be a universal response among people in both impoverished countries and rich nations, according to new research published by the American Psychological Association. "Our findings suggest that the psychological reward experienced from helping others may be deeply ingrained in human nature, emerging in diverse cultural and economic contexts," said lead author Lara Aknin, PhD, of Simon Fraser University in Canada. The findings provide the first empirical evidence that "the ...

Cell therapy a little more concrete thanks to VIB research

2013-02-21

Cell therapy is a promising alternative to tissue and organ transplantation for diseases that are caused by death or poor functioning of cells. Considering the ethical discussions surrounding human embryonic stem cells, a lot is expected of the so-called 'induced pluripotent stem cells' (iPS cells). However, before this technique can be applied effectively, a lot of research is required into the safety and efficacy of such iPS cells. VIB scientists associated to the UGent have developed a mouse model that can advance this research to the next step. Lieven Haenebalcke ...

VHA plays leading role in health information technology implementation and research

2013-02-21

Philadelphia, Pa. (February 21, 2013) - The Veterans Health Administration (VHA) is aiming to become a leader in using health information technology (HIT) to change the way patients experience medical care, to decrease medical mistakes, and to improve health outcomes. A special March supplement of Medical Care highlights new research into the many and varied types of HIT projects being explored to improve the quality of patient care throughout the VHA system. Medical Care is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health. The special issue ...

Antibacterial protein's molecular workings revealed

2013-02-21

On the front lines of our defenses against bacteria is the protein calprotectin, which "starves" invading pathogens of metal nutrients. Vanderbilt investigators now report new insights to the workings of calprotectin – including a detailed structural view of how it binds the metal manganese. Their findings, published online before print in the Proceedings of the National Academy of Sciences, could guide efforts to develop novel antibacterials that limit a microbe's access to metals. The increasing resistance of bacteria to existing antibiotics poses a severe threat to ...

When water speaks

2013-02-21

Why certain catalyst materials work more efficiently when they are surrounded by water instead of a gas phase is unclear. RUB chemists have now gleamed some initial answers from computer simulations. They showed that water stabilises specific charge states on the catalyst surface. "The catalyst and the water sort of speak with each other" says Professor Dominik Marx, depicting the underlying complex charge transfer processes. His research group from the Centre for Theoretical Chemistry also calculated how to increase the efficiency of catalytic systems without water by ...

Sniffing out the side effects of radiotherapy may soon be possible

2013-02-21

Researchers at the University of Warwick and The Royal Marsden NHS Foundation Trust have completed a study that may lead to clinicians being able to more accurately predict which patients will suffer from the side effects of radiotherapy. Gastrointestinal side effects are commonplace in radiotherapy patients and occasionally severe, yet there is no existing means of predicting which patients will suffer from them. The results of the pilot study, published in the journal Sensors, outline how the use of an electronic nose and a newer technology, FAIMS (Field Asymmetric ...

LAST 30 PRESS RELEASES:

From blood sugar to brain relief: GLP-1 therapy slashes migraine frequency

Variability in heart rate during sleep may reveal early signs of stroke, depression or cognitive dysfunction, new study shows

New method to study catalysts could lead to better batteries

Current Molecular Pharmacology impact factor rises to 2.9, achieving Q2 ranking in the Pharmacology & Pharmacy category in 2024 JCR

More time with loved ones for cancer patients spared radiation treatment

New methods speed diagnosis of rare genetic disease

Genetics of cardiomyopathy risk in cancer survivors differ by age of onset

Autism inpatient collection releases genetic, phenotypic data for more than 1,500 children with autism

Targeting fusion protein’s role in childhood leukemia produces striking results

Clear understanding of social connections propels strivers up the social ladder

New research reveals why acute and chronic pain are so different – and what might make pain last

Stable cooling fostered life, rapid warming brought death: scientists use high-resolution fusuline data reveal evolutionary responses to cooling and warming