First experience with real-time magnetic resonance imaging-based investigation of respiratory influence on cardiac function in pediatric congenital heart disease patients with chronic right ventricular volume overload.

Background: Congenital heart disease (CHD) is often associated with chronic right ventricular (RV) volume overload. Real-time magnetic resonance imaging (MRI) enables the analysis of cardiac function during free breathing.

Objective: To evaluate the influence of respiration in pediatric patients with CHD and chronic RV volume overload.

Hyperinsulinemic Hypoglycemia Associated with a Ca1.2 Variant with Mixed Gain- and Loss-of-Function Effects.

The voltage-dependent L-type calcium channel isoform Ca1.2 is critically involved in many physiological processes, e.g.

Comparison of cardiac volumetry using real-time MRI during free-breathing with standard cine MRI during breath-hold in children.

Background: Cardiac real-time magnetic resonance imaging (RT-MRI) provides high-quality images even during free-breathing. Difficulties in post-processing impede its use in clinical routine.

Objective: To demonstrate the feasibility of quantitative analysis of cardiac free-breathing RT-MRI and to compare image quality and volumetry during free-breathing RT-MRI in pediatric patients to standard breath-hold cine MRI.

Spirometry-based reconstruction of real-time cardiac MRI: Motion control and quantification of heart-lung interactions.

Purpose: To test the feasibility of cardiac real-time MRI in combination with retrospective gating by MR-compatible spirometry, to improve motion control, and to allow quantification of respiratory-induced changes during free-breathing.

Methods: Cross-sectional real-time MRI (1.5T; 30 frames/s) using steady-state free precession contrast during free-breathing was combined with MR-compatible spirometry in healthy adult volunteers (n = 4).

A new model to perform electrophysiological studies in the early embryonic mouse heart.

Background: The first electrocardiograms (ECGs) have been recorded with a capillary electrometer in the late 19(th) century by John Burdon Sanderson and Augustus Waller. In 1903 Willem Einthoven used the much more sensitive string galvanometer and was awarded Nobel Price in Medicine for this discovery. Though the physical principles of that era are still in use, there have been many advances but also challenges in cardiac electrophysiology over the last decades.

Time-course of the electrophysiological maturation and integration of transplanted cardiomyocytes.

Electrophysiological maturation and integration of transplanted cardiomyocytes are essential to enhance safety and efficiency of cell replacement therapy. Yet, little is known about these important processes. The aim of our study was to perform a detailed analysis of electrophysiological maturation and integration of transplanted cardiomyocytes.

Brown-Vialetto-Van Laere syndrome: a riboflavin-unresponsive patient with a novel mutation in the C20orf54 gene.

Brown-Vialetto-Van Laere syndrome (Online Mendelian Inheritance in Man number 211530) is a neurodegenerative disorder characterized by pontobulbar palsy affecting cranial nerves (mainly VII-XII). Sensorineural deafness is often the leading sign, followed by other neurologic signs. Inheritance is often autosomal recessive, with mutations in the C20orf54 gene (Online Mendelian Inheritance in Man number 613350).

Contractile properties of early human embryonic stem cell-derived cardiomyocytes: beta-adrenergic stimulation induces positive chronotropy and lusitropy but not inotropy.

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) provide the unique opportunity to study the very early development of the human heart. The aim of this study was to investigate the effect of calcium and beta-adrenergic stimulation on the contractile properties of early hESC-CMs. Beating clusters containing hESC-CMs were co-cultured in vitro with noncontractile slices of neonatal murine ventricles.

Urinary NT-proBNP, NGAL, and H-FABP may predict hemodynamic relevance of patent ductus arteriosus in very low birth weight infants.

Background: Hemodynamically significant patent ductus arteriosus (hsPDA) is the most common functional cardiovascular disease in preterm infants. The necessity to treat hsPDA can neither be derived solely from clinical nor from echocardiographic criteria.

Objective: The aim of this study was to establish non-invasive parameters which can differentiate hsPDA from non-hsPDA.

Fibroblasts support functional integration of purified embryonic stem cell-derived cardiomyocytes into avital myocardial tissue.

Transplantation of purified pluripotent stem cell-derived cardiomyocytes into damaged myocardium might become a therapy to improve contractile function after myocardial infarction. However, engraftment remains problematic. Aim of this study was to investigate whether murine embryonic fibroblasts (MEFs) support the functional integration of purified embryonic stem cell-derived cardiomyocytes (ES-CMs).

Comparison of contractile behavior of native murine ventricular tissue and cardiomyocytes derived from embryonic or induced pluripotent stem cells.

Cardiomyocytes generated from embryonic stem cells (ESCs) and induced pluripotent stem (iPS) cells are suggested for repopulation of destroyed myocardium. Because contractile properties are crucial for functional regeneration, we compared cardiomyocytes differentiated from ES cells (ESC-CMs) and iPS cells (iPS-CMs). Native myocardium served as control.

Fibroblasts facilitate the engraftment of embryonic stem cell-derived cardiomyocytes on three-dimensional collagen matrices and aggregation in hanging drops.

There is growing interest in the use of cardiomyocytes purified from embryonic stem (ES) cells for tissue engineering and cardiomyoplasty. However, most transplanted cells are lost shortly after transplantation due to the lack of integration into the host tissue and subsequent apoptosis. Here we examine whether murine embryonic fibroblasts (MEFs) can support the integration of purified murine ES cell-derived cardiomyocytes in a 3-dimensional tissue culture model based on a freezed-dryed collagen matrix with tubular structure.

Physiological differences between transplanted and host tissue cause functional decoupling after in vitro transplantation of human embryonic stem cell-derived cardiomyocytes.

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) might provide cells to repopulate injured myocardium. Electrical coupling of these cells to the host myocardium is a prerequisite for improved functionality. The aim of this study was to investigate electrical interaction of hESC-CMs with myocardial tissue and to identify factors challenging functional integration.

Biological pacemakers: characterization in an in vitro coculture model.

Background: Biological pacemakers could be an alternative or complement to electronic pacemakers. Embryonic stem cells (ESCs) can be differentiated in vitro to spontaneously active cells. Although numerous studies show that ESC-derived cardiomyocytes (ESC-CMs) and other cell types are capable to exert pacemaker function in vivo, detailed analyses of pattern and safety of conduction on a tissue level are rare.

Neonatal murine heart slices. A robust model to study ventricular isometric contractions.

Background/aims: Cardiac function is increasingly studied using murine models. However, current multicellular preparations to investigate contractile properties have substantial technical and biological limitations and are especially difficult to apply to the developing murine heart.

Methods: Newborn murine hearts were cut with a vibratome into viable tissue slices.

Electrophysiological maturation and integration of murine fetal cardiomyocytes after transplantation.

In the present study, we investigated the electrophysiological maturation and integration of immature cardiomyocytes after transplantation; maturation and integration are essential to achieve the cardiac regeneration. Murine fetal cardiomyocytes (FCMs) (d12.5-d15.

Regulation of Na+/Ca2+ exchange current in the normal and failing heart.

Cardiac NCX is modulated by diverse regulatory elements. Although there is consensus about the regulatory function of Na+ and Ca2+ and other elements, for example, ATP, there is still a controversial debate about the functional role of cyclic nucleotides and protein kinases. Future studies should focus on that topic since disturbances of cAMP/cGMP concentration and kinase activity may lead to severe functional disorders in the diseased heart.

Early administration of surfactant in spontaneous breathing with nCPAP: feasibility and outcome in extremely premature infants (postmenstrual age

Background: Spontaneous breathing supported by nasal continuous positive airway pressure (nCPAP) is thought to have some advantages compared with mechanical ventilation in extremely premature infants. In addition, early or prophylactic surfactant administration has been shown to be superior to delayed use. A strategy to combine these two principles was tested in our neonatal intensive care unit (NICU).

Force measurements of human embryonic stem cell-derived cardiomyocytes in an in vitro transplantation model.

Human embryonic stem cell (hESC)-derived cardiomyocytes have been suggested for cardiac cell replacement therapy. However, there are no data on loaded contractions developed by these cells and the regulation thereof. We developed a novel in vitro transplantation model in which beating cardiomyocytes derived from hESCs (line H1) were isolated and transplanted onto noncontractile, ischemically damaged ventricular slices of murine hearts.

Engraftment of engineered ES cell-derived cardiomyocytes but not BM cells restores contractile function to the infarcted myocardium.

Cellular cardiomyoplasty is an attractive option for the treatment of severe heart failure. It is, however, still unclear and controversial which is the most promising cell source. Therefore, we investigated and examined the fate and functional impact of bone marrow (BM) cells and embryonic stem cell (ES cell)-derived cardiomyocytes after transplantation into the infarcted mouse heart.

Wireless Holter transmission in suspected dysrhythmias.

Background: In patients with a history of possible dysrhythmias, documentation of an episode is mandatory before any form of treatment is given. Holter recordings with wireless telemetry offer the possibility of continuously recording electrocardiograms for days or even weeks with instantaneous analysis of the data in the physician's office.

Methods: Thirty-seven patients (20 male; median age, 8.

Ventricular slices of adult mouse hearts--a new multicellular in vitro model for electrophysiological studies.

Aim: We established a preparation of adult murine ventricular slices suitable for electrophysiological recordings as a new in vitro model of adult myocardium with preserved in vivo tissue structure.

Methods: Short axis slices (thickness: 150 microm) of adult murine ventricles were prepared with a microtome. Sharp glass electrodes were used for measurements of action potentials (APs) at stimulation frequencies of 2 Hz and 10 Hz.