Left ventricle hypertrophy and re-modeling in children with essential hypertension: does the race matter?

BACKGROUND: This is the first study to report on the impact of race on differences in the prevalence of echocardiographic left ventricular hypertrophy and left ventricular adaptation at the time of diagnosis of essential hypertension in children. METHODS: This cross-sectional, single-centre study included patients aged 3-18 years who had newly diagnosed essential hypertension. Echocardiography was used to assess left ventricular mass index and left ventricular relative wall thickness. An left ventricular mass index > the 95th percentile for age and gender, and an left ventricular relative wall thickness > 0.42, were used to diagnose left ventricular hypertrophy and concentric adaptation. Various echocardiographic parameters were compared between African Americans and Caucasians. RESULTS: The study included 422 patients (289 African Americans and 133 Caucasians) diagnosed with essential hypertension at a median age of 14.6 (interquartile range; 12.1-16.3) years. Eighty-eight patients (20.9%) had left ventricular hypertrophy. There was no statistically significant difference in the prevalence of left ventricular hypertrophy between African Americans and Caucasians (22.5% versus 17.3%, p=0.22). The median left ventricular relative wall thickness was 0.35 (0.29-0.43), and 114 patients (27.0%) had an left ventricular relative wall thickness > 0.42. The presence of an left ventricular relative wall thickness > 0.42 was significantly higher among African Americans compared to Caucasians (30.1% versus 20.3%, p = 0.04). The African American race was a strong predictor for an left ventricular relative wall thickness > 0.42 (odds ratio 1.7, p = 0.04), but not for left ventricular mass index > the 95th percentile (p = 0.22). Overweight/obesity was a strong predictor for an left ventricular mass index > the 95th percentile. CONCLUSIONS: There was no difference in the prevalence of left ventricular hypertrophy in children with essential hypertension of different races. Obesity, rather than being African American, is associated with left ventricular hypertrophy.

Aged hind-limb clasping experimental autoimmune encephalomyelitis models aspects of the neurodegenerative process seen in multiple sclerosis.

Experimental autoimmune encephalomyelitis (EAE) is the most common model of multiple sclerosis (MS). This model has been instrumental in understanding the events that lead to the initiation of central nervous system (CNS) autoimmunity. Though EAE has been an effective screening tool for identifying novel therapies for relapsing-remitting MS, it has proven to be less successful in identifying therapies for progressive forms of this disease. Though axon injury occurs in EAE, it is rapid and acute, making it difficult to intervene for the purpose of evaluating neuroprotective therapies. Here, we describe a variant of spontaneous EAE in the 2D2 T cell receptor transgenic mouse (2D2+ mouse) that presents with hind-limb clasping upon tail suspension and is associated with T cell-mediated inflammation in the posterior spinal cord and spinal nerve roots. Due to the mild nature of clinical signs in this model, we were able to maintain cohorts of mice into middle age. Over 9 mo, these mice exhibited a relapsing-remitting course of hind-limb clasping with the development of progressive motor deficits. Using a combined approach of ex vivo magnetic resonance (MR) imaging and histopathological analysis, we observed neurological progression to associate with spinal cord atrophy, synapse degradation, and neuron loss in the gray matter, as well as ongoing axon injury in the white matter of the spinal cord. These findings suggest that mild EAE coupled with natural aging may be a solution to better modeling the neurodegenerative processes seen in MS.

Invasive Coronary Assessment in a 9-Year-Old With Anomalous Aortic Origin of the Left Coronary Artery.

A previously healthy nine-year-old boy with anomalous aortic origin of the left coronary artery (AAOLCA) with high-risk anatomy demonstrated negative stress on magnetic resonance imaging. Invasive cardiac catheterization for intracoronary flow measurement was performed and demonstrated compromised coronary flow during pharmacologic stress and significant stenosis on angiography. The patient underwent surgical intervention with normalization of coronary flow upon postoperative evaluation. Invasive intracoronary flow determination with angiography under provocative stress is emerging as a critical data point for risk stratification and management decision-making in high-risk AAOLCA patients with negative noninvasive perfusion studies.

Brain Development and Heart Function after Systemic Single-Agent Chemotherapy in a Mouse Model of Childhood Leukemia Treatment.

PURPOSE: Chemotherapy for childhood acute lymphoblastic leukemia (ALL) can cause late-appearing side effects in survivors that affect multiple organs, including the heart and brain. However, the complex ALL treatment regimen makes it difficult to isolate the causes of these side effects and impossible to separate the contributions of individual chemotherapy agents by clinical observation. Using a mouse model, we therefore assessed each of eight representative, systemically-administered ALL chemotherapy agents for their impact on postnatal brain development and heart function. EXPERIMENTAL DESIGN: Mice were treated systemically with a single chemotherapy agent at an infant equivalent age, then allowed to age to early adulthood (9 weeks). Cardiac structure and function were assessed using in vivo high-frequency ultrasound, and brain anatomy was assessed using high-resolution volumetric ex vivo MRI. In addition, longitudinal in vivo MRI was used to determine the time course of developmental change after vincristine treatment. RESULTS: Vincristine, doxorubicin, and methotrexate were observed to produce the greatest deficiencies in brain development as determined by volumes measured on MRI, whereas doxorubicin, methotrexate, and l-asparaginase altered heart structure or function. Longitudinal studies of vincristine revealed widespread volume loss immediately following treatment and impaired growth over time in several brain regions. CONCLUSIONS: Multiple ALL chemotherapy agents can affect postnatal brain development or heart function. This study provides a ranking of agents based on potential toxicity, and thus highlights a subset likely to cause side effects in early adulthood for further study.