Objective-The similarities between valvular and vascular lesions suggest pathological initiation mediated through endothelium, but the role of hemodynamics in valvular endothelial biology is poorly understood. Methods and Results-Monolayers of porcine aortic endothelial cells (PAECs) or porcine aortic valve endothelial cells (PAVECs) were exposed to 20 dyne/cm 2 steady laminar shear stress for 48 hours, with static cultures serving as controls. Multiple microarray comparisons were made using RNA from sheared and control batches of both cell types. More than 400 genes were significantly differentially expressed in each comparison group. The resulting profiles were validated at the transcription and protein level and expression patterns confirmed in vivo by immunohistochemistry. PAVECs were found to be less intrinsically inflammatory than PAECs, but both cell types expressed similar antioxidant and antiinflammatory genes in response to shear stress. PAVECs expressed more genes associated with chondrogenesis, whereas PAECs expressed osteogenic genes, and shear stress had a protective effect against calcification. Conclusions-Transcriptional differences between PAVECs and PAECs highlight the valvular endothelial cell as a distinct organ system and suggest more attention needs to be given to valvular cells to further our understanding of similarities and differences between valvular and vascular pathology. Key Words: aortic valve Ⅲ shear stress Ⅲ inflammation Ⅲ calcification Ⅲ endothelial cell A ortic valve disease is associated with significant mortality and morbidity and is a strong risk factor for additional cardiovascular events. 1,2 Valvular degeneration is characterized by the development of stenosis or insufficiency, and by the time it is clinically manifested, it is usually only treatable by prosthetic valve replacement. 3 Explants of diseased valves reveal a wide spectrum of pathology, including sclerotic and calcific lesions, thrombus formations, bacterial vegetations, and fractured matrix fibers. 4,5 Aortic valve disease was originally thought to be the result of the continuous barrage of hemodynamic and mechanical forces over time, but recent evidence suggests a much more active biological progression involving inflammation, oxidation, angiogenesis, calcification, and osteogenesis. 6 -8 The vascular endothelium is a critical mediator of hemodynamic and humoral stimuli, and that endothelial inflammation and atherosclerosis occur preferentially at sites of disturbed or oscillatory flow. 9 Valvular endothelial dysfunction is also a hallmark of leaflet degeneration, and similarly characterized by the expression of proinflammatory adhesion receptors. 10,11 Interestingly, much of the aforementioned valvular pathology seems to occur preferentially on the aortic surface of the leaflet, which experiences a complex circulating flow that is different from the unidirectional flow on the ventricular side of the leaflet. This suggests that disturbed flow may play a causal role in the initiation of valvular pathology...
This article unpacks the stigma associated with a developmental disability at work, specifically autism spectrum disorders (ASD), by presenting findings from 2 studies-one interview-based and the other survey-based. Drawing on in-depth interviews with individuals on the autism spectrum, the first study showed that a clinical diagnosis of autism is a milestone event that triggered both positive (silver linings) and negative (dark clouds) responses to work. These positive and negative responses were shaped by the age at which the diagnosis occurred as well as specific work-related contingencies-identity management (disclosing or not disclosing), the importance of the social demands imposed by the job, and organizational support policies for autism. The second study developed and tested propositions derived from the qualitative data by using survey data gathered from working adults with ASD. Results showed that, compared with individuals diagnosed later in life, individuals who were diagnosed at an earlier age experienced greater organization-based self-esteem and lower perceived discrimination when they disclosed their disability, worked in jobs that placed lower social demands on them, or were employed in organizations that offered policies to support workers with ASD. We conclude that, depending on the age of diagnosis, attributes of the employment context can trigger stigma-related threat in different ways and we outline important practical implications of these findings.
Before the 1990s, research on the early identification and prevention of severe behavior disorders (SBDs), such as aggression, self-injury, and stereotyped behavior, among young children with intellectual and developmental disabilities (IDD), was mostly done with children 3 years or older. More recent work suggests that signs of SBDs may occur as early as 6 months in some infants. The present study combined a cross-sectional and longitudinal approach to examine SBDs in 180 young children aged 4–48 months recruited through mass screening, then receiving an interdisciplinary evaluation and six-month follow-ups for one year. Twelve potential risk factors related to SBDs were examined. Eight of these risk factors, including age, gender, diagnosis, intellectual and communication levels, visual impairment, parent education, family income, were differentially related to scores for Aggression, SIB, and Stereotyped Behavior subscales on the Behavior Problems Inventory (BPI-01) at initial interdisciplinary evaluation. BPI-01 scores decreased over the year for 57% of the children and increased for 43%. The amount of decrease on each BPI-01 subscale varied with age, gender, and diagnosis.
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