180 research outputs found
Analog comparator design and testing techniques in a linear array fabricated using a complementary bipolar technology
Immunolocalization of basic fibroblast growth factor receptors in internal thoracic artery and saphenous vein grafts
Recommended from our members
Memorial Drive Revitalization (Chicopee, MA)
The goal of the Master of Regional Planning Studio is to develop a student’s techniques for collecting, analyzing, and synthesizing spatial and non-spatial data and then presenting that collective data in a manner (i.e., report, video, presentation, and charettes) that is understandable to academics, professionals, and the public. Planning Studio allows students to integrate knowledge from coursework and research, and apply such knowledge to resolving representative planning problems. At UMASS Amherst, these problems are found in neighborhood, rural, urban, and/or regional settings.
In the fall of 2014, three local governments contracted with the MRP Studio to create separate vision plans that focused on key aspects of community revitalization. The City of Chicopee tasked the graduate student team (Hills House Planners) with developing a conceptual vision plan for Memorial Drive.” Currently, the Chicopee Planning Department lacked critical planning data for the corridor, and also has no adopted citywide master plan guiding development. The new vision seeks to include not only the existing car oriented infrastructure, but also to better integrate other uses for Memorial Drive, as well as a residential and commercial rebranding
Pneumomediastinum Due to Intractable Hiccup as the Presenting Symptom of Multiple Sclerosis
Pneumomediastinum and subcutaneous emphysema generally occurs following trauma to the esophagus or lung. It also occurs spontaneously in such situations of elevating intrathoracic pressure as asthma, excessive coughing or forceful straining. We report here on the rare case of a man who experienced the signs of pneumomediastinum and subcutaneous emphysema after a prolonged bout of intractable hiccup as the initial presenting symptoms of multiple sclerosis
Hybrid Approach for the Treatment of Thoracic Aortic Arch Aneurysm in a Patient With Chronic Obstructive Lung Disease and Retrosternal Adhesion
A 73-year-old woman with a history of chronic hypertension and severe chronic obstructive pulmonary disease, presented to a district general hospital with thoracic pain in a profound state of shock. She was diagnosed with cardiac tamponade, severe mitral regurgitation, and Stanford type A (Debakey type I) intramural hematoma. Her ascending aorta was of a significant size and therefore emergent repair was done to replace the ascending aorta and mitral valve. After 6 months, an increased aneurysmal size of 6.0 cm was observed in a follow up contrast-enhanced computed tomography angiography. The patient was successfully treated by a staged hybrid procedure involving initial supra-aortic reconstruction
Exercise and Physical Activity for the Post–Aortic Dissection Patient: The Clinician's Conundrum
Despite the paucity of evidence, it is often presumed, and is physiologically plausible, that sudden, acute elevations in blood pressure may transiently increase the risk of recurrent aortic dissection (AD) or rupture in patients with a prior AD, because a post‐dissection aorta is almost invariably dilated and may thus experience greater associated wall stress as compared with a nondilated aorta. Few data are available regarding the specific types and intensities of exercise that may be both safe and beneficial for this escalating patient population. The purpose of this editorial/commentary is to further explore this conundrum for clinicians caring for and counseling AD survivors. Moderate‐intensity cardiovascular activity may be cardioprotective in this patient cohort. It is likely that severe physical activity restrictions may reduce functional capacity and quality of life in post‐AD patients and thus be harmful, underscoring the importance of further exploring the role of physical activity and/or structured exercise in this at‐risk patient population.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116077/1/clc22481_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/116077/2/clc22481.pd
Identification of Genomic Aberrations by Array Comparative Genomic Hybridization in Patients with Aortic Dissections
Mechanical behaviour and rupture of normal and pathological human ascending aortic wall
The mechanical properties of aortic wall, both healthy and pathological, are needed in order to develop and improve diagnostic and interventional criteria, and for the development of mechanical models to assess arterial integrity. This study focuses on the mechanical behaviour and rupture conditions of the human ascending aorta and its relationship with age and pathologies. Fresh ascending aortic specimens harvested from 23 healthy donors, 12 patients with bicuspid aortic valve (BAV) and 14 with aneurysm were tensile-tested in vitro under physiological conditions. Tensile strength, stretch at failure and elbow stress were measured. The obtained results showed that age causes a major reduction in the mechanical parameters of healthy ascending aortic tissue, and that no significant differences are found between the mechanical strength of aneurysmal or BAV aortic specimens and the corresponding age-matched control group. The physiological level of the stress in the circumferential direction was also computed to assess the physiological operation range of healthy and diseased ascending aortas. The mean physiological wall stress acting on pathologic aortas was found to be far from rupture, with factors of safety (defined as the ratio of tensile strength to the mean wall stress) larger than six. In contrast, the physiological operation of pathologic vessels lays in the stiff part of the response curve, losing part of its function of damping the pressure waves from the heart
Gene Expression Signature in Peripheral Blood Detects Thoracic Aortic Aneurysm
BACKGROUND: Thoracic aortic aneurysm (TAA) is usually asymptomatic and associated with high mortality. Adverse clinical outcome of TAA is preventable by elective surgical repair; however, identifying at-risk individuals is difficult. We hypothesized that gene expression patterns in peripheral blood cells may correlate with TAA disease status. Our goal was to identify a distinct gene expression signature in peripheral blood that may identify individuals at risk for TAA. METHODS AND FINDINGS: Whole genome gene expression profiles from 94 peripheral blood samples (collected from 58 individuals with TAA and 36 controls) were analyzed. Significance Analysis of Microarray (SAM) identified potential signature genes characterizing TAA vs. normal, ascending vs. descending TAA, and sporadic vs. familial TAA. Using a training set containing 36 TAA patients and 25 controls, a 41-gene classification model was constructed for detecting TAA status and an overall accuracy of 78+/-6% was achieved. Testing this classifier on an independent validation set containing 22 TAA samples and 11 controls yielded an overall classification accuracy of 78%. These 41 classifier genes were further validated by TaqMan real-time PCR assays. Classification based on the TaqMan data replicated the microarray results and achieved 80% classification accuracy on the testing set. CONCLUSIONS: This study identified informative gene expression signatures in peripheral blood cells that can characterize TAA status and subtypes of TAA. Moreover, a 41-gene classifier based on expression signature can identify TAA patients with high accuracy. The transcriptional programs in peripheral blood leading to the identification of these markers also provide insights into the mechanism of development of aortic aneurysms and highlight potential targets for therapeutic intervention. The classifier genes identified in this study, and validated by TaqMan real-time PCR, define a set of promising potential diagnostic markers, setting the stage for a blood-based gene expression test to facilitate early detection of TAA
Post-stenotic aortic dilatation
Aortic stenosis is the most common valvular heart disease affecting up to 4% of the elderly population. It can be associated with dilatation of the ascending aorta and subsequent dissection. Post-stenotic dilatation is seen in patients with AS and/or aortic regurgitation, patients with a haemodynamically normal bicuspid aortic valve and following aortic valve replacement. Controversy exists as to whether to replace the aortic root and ascending aorta at the time of aortic valve replacement, an operation that potentially carries a higher morbidity and mortality. The aetiology of post-stenotic aortic dilatation remains controversial. It may be due to haemodynamic factors caused by a stenotic valve, involving high velocity and turbulent flow downstream of the stenosis, or due to intrinsic pathology of the aortic wall. This may involve an abnormality in the process of extracellular matrix remodelling in the aortic wall including inadequate synthesis, degradation and transport of extracellular matrix proteins. This article reviews the aetiology, pathology and management of patients with post-stenotic aortic dilatation
- …