3,609 research outputs found
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Natural History Of Syphilitic Aortitis
No large studies of cardiovascular syphilis at necropsy have been reported since 1964. We examined at necropsy 90 patients who had characteristic morphologic findings of syphilitic aortitis. None had ever undergone cardiovascular surgery. With the exception of 2 cases seen more recently, the hearts and aortas of the 90 patients were examined and categorized by one of us (W.C.R.) from 1966 to 1990. All 90 had extensive involvement of the tubular portion of the ascending aorta by the syphilitic process, which spared the sinuses of Valsalva in all but 4 patients. The aortic arch was also involved in 49 (91%) of 54 patients and the descending thoracic aorta in 47 (90%) of 52 patients. Syphilis was the cause of death in 23 (26%) of the 90 patients. It was secondary to rupture of the ascending or descending thoracic aorta in 12, severe aortic regurgitation leading to heart failure in 10, and severe narrowing of the aortic ostium of the right coronary artery in 1 patient. Of the 40 patients who had undergone serologic testing for syphilis, 28 (70%) had a positive (reactive) finding. Those patients with a negative or nonreactive test or who did not undergo a serologic test for syphilis had morphologic and histologic findings in the aorta at necropsy similar to the findings of those patients who had had a positive serologic test for syphilis. In conclusion, cardiovascular syphilis has not disappeared. In patients with dilated ascending aortas, with or without aortic regurgitation, a serologic test for syphilis is recommended. If the findings are positive or if characteristic morphologic features of cardiovascular syphilis are suspected, irrespective of the results of the serologic tests, antibiotic therapy appears desirable. (C) 2009 Elsevier Inc. All rights reserved. (Am J Cardiol 2009;104:1578-1587)Integrative Biolog
Gender differences in participatory leadership: An examination of principals’ time spent working with others
The purpose of this study was to examine whether female principals have a more participatory style compared to their male counterparts by examining principals’ daily time allocation patterns. The study analyzed data from End of Day (EOD) survey logs from principals in an urban school district. Results from hierarchical linear modeling (HLM) results showed that female principals, when compare to male principals, spent a higher proportion of their time working with others in planning/setting goals. At the same time, there were no differences in how principals allocated their time total working alone or working with others and their time distribution in other leadership domains. The findings suggest that gender differences in leadership style depend on specific activity domains and that there are significant differences in the key domain of strategic planning
Presence Of A Congenitally Bicuspid Aortic Valve Among Patients Having Combined Mitral And Aortic Valve Replacement
Although bicuspid aortic valve occurs in an estimated 1% of adults and mitral valve prolapse in an estimated 5% of adults, occurrence of the 2 in the same patient is infrequent. During examination of operatively excised aortic and mitral valves because of dysfunction (stenosis and/or regurgitation), we encountered 16 patients who had congenitally bicuspid aortic valves associated with various types of dysfunctioning mitral valves. Eleven of the 16 patients had aortic stenosis (AS): 5 of them also had mitral stenosis, of rheumatic origin in 4 and secondary to mitral annular calcium in 1; the other 6 with aortic stenosis had pure mitral regurgitation (MR) secondary to mitral valve prolapse in 3, to ischemia in 2, and to unclear origin in 1. Of the 5 patients with pure aortic regurgitation, each also had pure mitral regurgitation: in 1 secondary to mitral valve prolapse and in 4 secondary to infective endocarditis. In conclusion, various types of mitral dysfunction severe enough to warrant mitral valve replacement occur in patients with bicuspid aortic valves. A proper search for mitral valve dysfunction in patients with bicuspid aortic valves appears warranted. (C) 2012 Elsevier Inc. All rights reserved. (Am J Cardiol 2012;109:263-271)Integrative Biolog
Raman Spectroscopy for Monitoring Strain on Graphene and Oxidation Corrosion on Nuclear Claddings
Raman scattering can explore a material’s structure, composition, and condition. In this chapter, we demonstrate the application of Raman scattering to monitor the change in the physical properties and chemical composition of materials. We provide two examples: (1) the Raman peak profile and shift reveal the strain in graphene induced by nanostructure and (2) the appearance and intensity of the Raman peaks indicate the oxidation corrosion on Zircaloy nuclear fuel cladding. The Raman spectroscopy is capable of providing evident and precise signals for the monitoring tasks. Through this research, we propose Raman spectroscopy to be a sensitive, accurate, and nondestructive tool for monitoring material conditions
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Influence of substrate on corneal epithelial cell viability within ocular surface models
Corneal tissue engineering has improved dramatically over recent years. It is now possible to apply these technological advancements to the development of superior in vitro ocular surface models to reduce animal testing. We aim to show the effect different substrates can have on the viability of expanded corneal epithelial cells and that those which more accurately mimic the stromal surface provide the most protection against toxic assault. Compressed collagen gel as a substrate for the expansion of a human epithelial cell line was compared against two well-known substrates for modeling the ocular surface (polycarbonate membrane and conventional collagen gel). Cells were expanded over 10 days at which point cell stratification, cell number and expression of junctional proteins were assessed by electron microscopy, immunohistochemistry and RT-PCR. The effect of increasing concentrations of sodium lauryl sulphate on epithelial cell viability was quantified by MTT assay. Results showed improvement in terms of stratification, cell number and tight junction expression in human epithelial cells expanded upon either the polycarbonate membrane or compressed collagen gel when compared to a the use of a conventional collagen gel. However, cell viability was significantly higher in cells expanded upon the compressed collagen gel. We conclude that the more naturalistic composition and mechanical properties of compressed collagen gels produces a more robust corneal model
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Immune factors preceding diagnosis of glioma: a Prostate Lung Colorectal Ovarian Cancer Screening Trial nested case-control study.
BackgroundEpidemiological studies of adult glioma have identified genetic and environmental risk factors, but much remains unclear. The aim of the current study was to evaluate anthropometric, disease-related, and prediagnostic immune-related factors for relationship with glioma risk.MethodsWe conducted a nested case-control study among the intervention arm of the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial. One hundred and twenty-four glioma cases were identified and each matched to four controls. Baseline characteristics were collected at enrollment and were evaluated for association with glioma status. Serum specimens were collected at yearly intervals and were analyzed for immune-related factors including TGF-β1, TNF-α, total IgE, and allergen-specific IgE. Immune factors were evaluated at baseline in a multivariate conditional logistic regression model, along with one additional model that incorporated the latest available measurement.ResultsA family history of glioma among first-degree relatives was associated with increased glioma risk (OR = 4.41, P = .002). In multivariate modeling of immune factors at baseline, increased respiratory allergen-specific IgE was inversely associated with glioma risk (OR for allergen-specific IgE > 0.35 PAU/L: 0.59, P = .03). A logistic regression model that incorporated the latest available measurements found a similar association for allergen-specific IgE (P = .005) and showed that elevated TGF-β1 was associated with increased glioma risk (P-value for trend <.0001).ConclusionThe results from this prospective prediagnostic study suggest that several immune-related factors are associated with glioma risk. The association observed for TGF-β1 when sampling closer to the time of diagnosis may reflect the nascent brain tumor's feedback on immune function
Effect Of Coronary Bypass And Valve Structure On Outcome In Isolated Valve Replacement For Aortic Stenosis
Reports differ regarding the effect of concomitant coronary artery bypass grafting (CABG) in patients who undergo aortic valve replacement (AVR) for aortic stenosis (AS), and no reports have described the effect of aortic valve structure in patients who undergo AVR for AS. A total of 871 patients aged 24 to 94 years (mean 70) whose AVR for AS was their first cardiac operation, with or without first concomitant CABG, were included. Patients who underwent mitral valve procedures were excluded. In comparison with the 443 patients (51%) who did not undergo CABG, the 428 (49%) who underwent concomitant CABG were significantly older, were more often male, had lower transvalvular peak systolic pressure gradients and larger valve areas, had lower frequencies of congenitally malformed aortic valves, had lighter valves by weight, had higher frequencies of systemic hypertension, and had longer stays in the hospital after AVR. Early and late (to 10 years) mortality were similar by propensity-adjusted analysis in patients who did and did not undergo concomitant CABG. Congenitally unicuspid or bicuspid valves occurred in approximately 90% of those aged 21 to 50, in nearly 70% in those aged 51 to 70 years, and in just over 30% in those aged 71 to 95 years. Unadjusted and adjusted survival was significantly higher in patients with unicuspid or bicuspid valves compared to those with tricuspid valves. In conclusion, although concomitant CABG had no effect on the adjusted probability of survival, the type of aortic valve (unicuspid or bicuspid vs tricuspid) significantly affected the unadjusted and adjusted probability of survival. (C) 2012 Elsevier Inc. All rights reserved. (Am J Cardiol 2012;109:1334-1340)Statistic
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