Objective
This cross-sectional study sought to confirm the presence and regional profile of previously reported changes in laminar cortical thickness in children and adolescents with Attention Deficit / Hyperactivity Disorder (ADHD) compared to typically developing healthy subjects.
Method
High-resolution MR images were obtained from 22 (19 male, 3 female; mean age: 11.7 years) children and adolescents with ADHD and 22 age and sex matched healthy control subjects (mean age: 11.7 years). Brain tissue volumes were estimated for each subject. Cortical pattern matching methods were used to sample measures of laminar thickness at high spatial frequency across homologous regions of cortex. Volume and thickness measures were compared across diagnostic groups with and without controlling for general intelligence. False discovery rate (FDR) correction confirmed regional results.
Results
Subjects with ADHD exhibited significant reductions in overall brain volume, gray matter volume and mean cortical thickness compared to healthy controls, while white matter volumes were significantly increased in ADHD. Highly significant cortical thinning (FDR-corrected p < .0006) was observed over large areas of frontal, temporal, parietal and occipital association cortices and aspects of motor cortex, but not within primary sensory regions.
Conclusions
Cortical thickness reductions present a robust neuroanatomical marker for child and adolescent ADHD. Observations of widespread cortical thinning expand upon earlier cross-sectional findings and provide further evidence to support that the neurobiological underpinnings of ADHD extend beyond prefrontal and subcortical circuits.
Exercise training prevented hypertension-enhanced cardiac Fas-dependent and mitochondria-dependent apoptotic pathways and enhanced cardiac pro-survival pathway in rat models. Our findings demonstrate new therapeutic effects of exercise training on hypertensive hearts for preventing apoptosis and enhancing survival.
Chondrosarcoma is the second most common sarcoma in bone malignancy and is characterized by a high metastatic potential. Angiogenesis is essential for the cancer metastasis. Endothelin-1 (ET-1) has been implicated in tumor angiogenesis and metastasis. However, the relationship of ET-1 with vascular endothelial growth factor (VEGF) expression and angiogenesis in human chondrosarcoma cells is mostly unknown. Here, we found that the expression of ET-1 and VEGF were correlated with tumor stage and were significantly higher than that in the normal cartilage. Exogenous ET-1 with chondrosarcoma cells promoted VEGF expression and subsequently increased migration and tube formation in endothelial progenitor cells. ET-1 increased VEGF expression and angiogenesis through ETAR, integrin-linked kinase (ILK), Akt and hypoxia-inducible factor-1α (HIF-1α) signaling cascades. Knockdown of ET-1 decreased VEGF expression and also abolished chondrosarcoma conditional medium-mediated angiogenesis in vitro as well as angiogenesis effects in the chick chorioallantoic membrane and Matrigel plug nude mice model in vivo. In addition, in the xenograft tumor angiogenesis model, knockdown of ET-1 significantly reduced tumor growth and tumor-associated angiogenesis. Taken together, these results indicate that ET-1 occurs through ETAR, ILK and Akt, which in turn activates HIF-1α, resulting in the activation of VEGF expression and contributing to the angiogenesis and tumor growth of human chondrosarcoma cells.
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