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ABSTRACT: Aortic stenosis is a common cardiac problem. Morphological aortic stenosis can be due to valvular, subvalvular and supravalvular causes. Subvalvular causes include subaortic rings and membranes, which usually manifest at a young age, depending on the size of the ring and the degree of obstruction. Recurrent (post-operative) stenosis is a rare potential problem. A case of recurrent subaortic stenosis due to a subaortic ring, 28 years after the initial surgical excision of the ring is presented.
The Canadian journal of cardiology 10/2003; 19(10):1189-91. · 3.36 Impact Factor
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ABSTRACT: Fibronectin, an extracellular matrix protein, is associated with the general process of tissue repair and is present in heart valves. In order to understand the cellular mechanisms of heart valve repair, we hypothesized that fibronectin is produced and secreted by valvular interstitial cells (VICs), and when up-regulated in VICs involved in active repair, it is associated with prominent fibrillar adhesions composed of tensin and alpha(5)beta(1) integrin. We investigated the interaction of porcine mitral VICs with the underlying fibronectin matrix and the formation and localization of focal and fibrillar adhesion complexes in an in vitro wound model.
Confluent monolayers of VICs were wounded with a 1-mm-wide cell scraper, maintained in standard media and 10% fetal bovine serum, and fixed at various time points after wounding. Immunohistochemistry was used to localize fibronectin, paxillin, tensin, and alpha(5)beta(1) integrin. F-actin was localized with an Alexa-Fluor-568-labeled phalloidin. Cells were examined with a scanning confocal laser microscope.
In response to in vitro mechanical wounding, migrating VICs at the wound edge expressed cytoplasmic fibronectin compared to nonwounded confluent monolayers. Over 24 to 48 h, fibrils were deposited into the subcellular space. Coincident with this, staining for alpha(5)beta(1) appeared, and tensin redistributed from focal adhesions to fibrillar adhesions, which colocalized with alpha(5)beta(1).
Fibronectin in association with fibrillar adhesions is a component of the matrix that may be secreted by migrating VICs to regulate repair at sites of valve injury.
Cardiovascular Pathology 16(4):203-11. · 2.07 Impact Factor
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Cardiovascular Pathology 12(2):91-3. · 2.07 Impact Factor
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Cardiovascular Pathology 11(6):351-3. · 2.07 Impact Factor
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ABSTRACT: Mechanical heart value prostheses have been in use since the 1950s. Many prostheses have been used for a while and then discontinued. Today, there are a large number and variety of prostheses in use and an even larger variety that are in place in patients. These may be explanted at any time for a number of reasons. It is essential for the practicing pathologist to be able to identify the prosthesis and be aware of some of its reported complications and modes of failure. This article, and a second one on bioprosthetic heart valves, is designed as a ready reference guide to heart valve prostheses, their important identifying features, their common complications, and modes of failure. It should help in the accurate identification of explanted prosthetic valves and more definitive reports. This accuracy of identification as well as tracking of abnormalities noted will, we hope, permit the identification of new failure modes and the recording of causes of failure of new (or even modified) prosthetic heart valves.
Cardiovascular Pathology 12(6):322-44. · 2.07 Impact Factor
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Cardiovascular Pathology 12(3):119-39. · 2.07 Impact Factor
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Cardiovascular Pathology 12(1):1-22. · 2.07 Impact Factor