Correlation of ECG and cardiac MRI for assessment of ventricular hypertrophy and dilatation in adults with repaired tetralogy of Fallot.

Background: Surgically repaired Tetralogy of Fallot (rTOF) is associated with progressive right ventricular hypertrophy (RVH) and dilation (RVD). Accurate estimation of RVH/RVD is vital for the ongoing management of this patient population. The utility of the ECG in evaluating patients with rTOF with pre-existing right bundle branch block (RBBB) has not been studied.

Arrhythmic and thromboembolic outcomes in adults with coarctation of the aorta.

Background: Adults with congenital heart disease (ACHD) experience a high prevalence of atrial arrhythmia (AA) and thromboembolic cerebrovascular complications. However, data on AA and associated long-term outcomes are limited in ACHD patients with coarctation of the aorta (CoA).

Objectives: This study aimed to characterize the prevalence and risk factors for AA and thromboembolic complications in adults with CoA.

Arrhythmic Mitral Valve Prolapse and Mitral Annulus Disjunction in Heritable Aortic Disease.

Patients with heritable aortic disease (HAD) have an increased risk of ventricular arrhythmias and sudden cardiac death. Although mitral valve prolapse is common in HAD, mitral annulus disjunction (MAD) has only recently been described in these patients. This under-recognized condition may be a contributing factor to otherwise unexplained ventricular arrhythmias and sudden cardiac death in patients with HAD.

Increasing age and atrial arrhythmias are associated with increased thromboembolic events in a young cohort of adults with repaired tetralogy of Fallot.

Background: Adults with repaired Tetralogy of Fallot (rTOF) comprise one of the largest cohorts among adults with congenital heart disease (ACHD). These patients have a higher burden of atrial arrhythmias (AA), leading to increased adverse events, including stroke and transient ischemic attack (TIA). However, the data on factors associated with stroke/TIA in rTOF are limited, and classic risk factors may not apply.

New Tmc1 Deafness Mutations Impact Mechanotransduction in Auditory Hair Cells.

Transmembrane channel-like protein isoform 1 (TMC1) is a major component of the mechano-electrical transducer (MET) channel in cochlear hair cells and is subject to numerous mutations causing deafness. We report a new dominant human deafness mutation, p.T422K, and have characterized the homologous mouse mutant, p.

Atrial arrhythmias and thromboembolic complications in adults post Fontan surgery.

Objective: Patients with Fontan surgery experience late complications in adulthood. We studied the factors associated with the development and maintenance of atrial arrhythmias and thromboembolic complications in an adult population with univentricuar physiology post Fontan surgery.

Methods: Single centre retrospective cohort study of patients ≥18 years of age with Fontan circulation followed at our quaternary care centre for more than 1 year were included.

A Postpartum Type A Dissection.

A 28-year-old woman with familial thoracic aortic aneurysm and dissection syndrome and a mildly dilated aorta presented 3 days postpartum with a type A aortic dissection. This case illustrates the unpredictability of this disease and the challenges with risk stratification of women with underlying aortopathy contemplating pregnancy. ().

A mutation reduces calcium permeability and expression of mechanoelectrical transduction channels in cochlear hair cells.

Mechanoelectrical transducer (MET) currents were recorded from cochlear hair cells in mice with mutations of transmembrane channel-like protein TMC1 to study the effects on MET channel properties. We characterized a mouse with a single-amino-acid mutation (D569N), homologous to a dominant human deafness mutation. Measurements were made in both wild-type and knockout mice.

BMP signaling regulates the fate of chondro-osteoprogenitor cells in facial mesenchyme in a stage-specific manner.

Background: Lineage tracing has shown that most of the facial skeleton is derived from cranial neural crest cells. However, the local signals that influence postmigratory, neural crest-derived mesenchyme also play a major role in patterning the skeleton. Here, we study the role of BMP signaling in regulating the fate of chondro-osteoprogenitor cells in the face.

Cochleovestibular nerve development is integrated with migratory neural crest cells.

The cochleovestibular (CV) nerve, which connects the inner ear to the brain, is the nerve that enables the senses of hearing and balance. The aim of this study was to document the morphological development of the mouse CV nerve with respect to the two embryonic cells types that produce it, specifically, the otic vesicle-derived progenitors that give rise to neurons, and the neural crest cell (NCC) progenitors that give rise to glia. Otic tissues of mouse embryos carrying NCC lineage reporter transgenes were whole mount immunostained to identify neurons and NCC.

Colonic enteric nervous system analysis during parenteral nutrition.

Introduction: Parenteral nutrition (PN) is a necessary therapy used to feed patients with gastrointestinal dysfunction. Unfortunately, PN results in intestinal atrophy and changes to host immune function. PN may also induce additional effects on gut motility that we hypothesized would result from changes in the enteric nervous system.

Tcof1 acts as a modifier of Pax3 during enteric nervous system development and in the pathogenesis of colonic aganglionosis.

Hirschsprung disease (HSCR) is a human congenital disorder, defined by the absence of ganglia from variable lengths of the colon. These ganglia comprise the enteric nervous system (ENS) and are derived from migratory neural crest cells (NCCs). The inheritance of HSCR is complex, often non-Mendelian and characterized by variable penetrance.

Balancing neural crest cell intrinsic processes with those of the microenvironment in Tcof1 haploinsufficient mice enables complete enteric nervous system formation.

The enteric nervous system (ENS) comprises a complex neuronal network that regulates peristalsis of the gut wall and secretions into the lumen. The ENS is formed from a multipotent progenitor cell population called the neural crest, which is derived from the neuroepithelium. Neural crest cells (NCCs) migrate over incredible distances to colonize the entire length of the gut and during their migration they must survive, proliferate and ultimately differentiate.

Sudden death and defibrillators in transposition of the great arteries with intra-atrial baffles: a multicenter study.

Background: Transposition of the great arteries with intra-atrial baffle repair is among the congenital heart defects at highest risk of sudden death. Little is known about mechanisms of sudden death and the role of implantable cardioverter defibrillators.

Methods And Results: We conducted a multicenter cohort study in patients with transposition of the great arteries to determine actuarial rates of implantable cardioverter defibrillator shocks, identify risk factors, assess underlying arrhythmias, and characterize complications.

Enteric nervous system stem cells derived from human gut mucosa for the treatment of aganglionic gut disorders.

Background & Aims: Enteric nervous system stem cells (ENSSCs) provide potential therapeutic tools to replenish absent ganglia in Hirschsprung's disease. Although full-thickness human postnatal gut tissue can be used to generate ENSSCs, reliance on its harvesting from surgical resection poses significant practical limitations. This study aimed to explore whether gut tissue obtained utilizing minimally invasive routine endoscopy techniques could be used to generate ENSSCs and whether such cells retain the potential to generate an ENS upon transplantation into aganglionic gut.

Critical numbers of neural crest cells are required in the pathways from the neural tube to the foregut to ensure complete enteric nervous system formation.

The enteric nervous system (ENS) is mainly derived from vagal neural crest cells (NCC) that arise at the level of somites 1-7. To understand how the size and composition of the NCC progenitor pool affects ENS development, we reduced the number of NCC by ablating the neural tube adjacent to somites 3-6 to produce aganglionic gut. We then back-transplanted various somite lengths of quail neural tube into the ablated region to determine the 'tipping point', whereby sufficient progenitors were available for complete ENS formation.

Implantable cardioverter-defibrillators in tetralogy of Fallot.

Background: Tetralogy of Fallot is the most common form of congenital heart disease in implantable cardioverter-defibrillator (ICD) recipients, yet little is known about the value of ICDs in this patient population.

Methods And Results: We conducted a multicenter cohort study in high-risk patients with Tetralogy of Fallot to determine actuarial rates of ICD discharges, identify risk factors, and characterize ICD-related complications. A total of 121 patients (median age 33.

The receptor tyrosine kinase RET regulates hindgut colonization by sacral neural crest cells.

The enteric nervous system (ENS) is formed from vagal and sacral neural crest cells (NCC). Vagal NCC give rise to most of the ENS along the entire gut, whereas the contribution of sacral NCC is mainly limited to the hindgut. This, and data from heterotopic quail-chick grafting studies, suggests that vagal and sacral NCC have intrinsic differences in their ability to colonize the gut, and/or to respond to signalling cues within the gut environment.

Development of the neural crest-derived intrinsic innervation of the human lung.

The formation of neural tissue, in association with airway smooth muscle (ASM), is a feature of normal lung development and function. Intrinsic neuronal tissue has recently been shown, in animal models, to be derived from neural crest cells (NCC). Since defects in NCC development underlie a range of disease states (neurocristopathies), it is important to determine the spatiotemporal development of NCC in the human lung, as defects in their development could have pathophysiologic implications.

Tyrosine kinase receptor RET is a key regulator of Peyer's patch organogenesis.

Normal organogenesis requires co-ordinate development and interaction of multiple cell types, and is seemingly governed by tissue specific factors. Lymphoid organogenesis during embryonic life is dependent on molecules the temporal expression of which is tightly regulated. During this process, haematopoietic 'inducer' cells interact with stromal 'organizer' cells, giving rise to the lymphoid organ primordia.

Maintenance of mammalian enteric nervous system progenitors by SOX10 and endothelin 3 signalling.

The transcriptional regulator SOX10 and the signalling molecule endothelin 3 have important roles in the development of the mammalian enteric nervous system (ENS). Using a clonal cell culture system, we show that SOX10 inhibits overt neuronal and glial differentiation of multilineage ENS progenitor cells (EPCs), without interfering with their neurogenic commitment. We also demonstrate that endothelin 3 inhibits reversibly the commitment and differentiation of EPCs along the neurogenic and gliogenic lineages, suggesting a role for this factor in the maintenance of multilineage ENS progenitors.

Hepatic stellate cells do not derive from the neural crest.

Background/aims: Hepatic stellate cells (HSC) have been hypothesised to derive from the neural crest, based on their expression of multiple neural/neuroendocrine features and their contacts with autonomic nerve endings.

Methods: We studied the emergence of HSC in the liver during embryonic development in a transgenic mouse line expressing yellow fluorescent protein (YFP) in all neural crest cells and their derivatives. Cellular YFP expression in these mice was compared with desmin expression between embryonic day (E) 11.

Enteric nervous system progenitors are coordinately controlled by the G protein-coupled receptor EDNRB and the receptor tyrosine kinase RET.

The enteric nervous system (ENS) in vertebrates is derived mainly from vagal neural crest cells that enter the foregut and colonize the entire wall of the gastrointestinal tract. Failure to completely colonize the gut results in the absence of enteric ganglia (Hirschsprung's disease). Two signaling systems mediated by RET and EDNRB have been identified as critical players in enteric neurogenesis.