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PK Woodard D Li EM Haacke PJ Dhawale S Kaushikkar B Barzilai AC Braverman PA Ludbrook AN Weiss JJ Brown SA Mirowitz TK Pilgram FR Gutierrez 《Canadian Metallurgical Quarterly》1998,170(4):883-888
OBJECTIVE: Our objective was to study the ability of three-dimensional MR angiography with retrospective respiratory gating to reveal stenoses in proximal coronary arteries on source and projection images. CONCLUSION: Proximal coronary artery stenoses can be identified using three-dimensional MR angiography with retrospective respiratory gating, both with projection images and on source images alone. Reasons for missed lesions included collateral vessels and retrograde flow distal to complete occlusion and volume averaging of vessels with adjacent structures. Causes of false-positive interpretations included small foci of decreased signal intensity distal to complete occlusion, partial volume effects on individual partitions, and regions of distal vessels leaving the imaging plane. 相似文献
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PK Downes 《Canadian Metallurgical Quarterly》1998,185(6):270-274
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Superantigens (SAgs) are extremely potent stimulants of T cell activity that have been implicated in the etiopathophysiology of inflammatory disease. Here, we tested the hypothesis that Staphylococcus aureus enterotoxin B (SEB), a model SAg, can alter epithelial transport and/or barrier functions via immune stimulation. Confluent monolayers of the human colonic T84 epithelial cell line, grown on filter supports, were cocultured with SEB +/- PBMC. Subsequently, T84 transport (consisting of baseline short-circuit current (Isc, indicates net ion transport) and secretory responses to carbachol and forskolin) and barrier functions (consisting of transepithelial resistance and fluxes of 3H-labeled mannitol and 51Cr-EDTA) were examined in Ussing chambers. T84 monolayers cocultured with SEB-activated PBMC displayed a time- and dose-dependent decrease in secretory responses to carbachol and forskolin and a significant increase in permeability. These dramatic changes in epithelial function were not due to reduced epithelial viability. Neutralizing Abs to IFN-gamma partially prevented the transport abnormalities, and Abs to TNF-alpha inhibited the increase in epithelial permeability. Abs to IL-1beta and IL-6 did not modulate the SEB-activated PBMC-induced T84 pathophysiology. Addition of TGF-beta2 to conditioned medium from SEB-activated PBMC partially inhibited the increase in T84 permeability but did not affect the transport abnormalities. We conclude that SAgs can elicit epithelial irregularities characteristic of enteric inflammation and that IFN-gamma and TNF-alpha are key mediators in this coculture model of epithelial dysfunction. Additionally, we would highlight the role that TGF-beta2 may play in preventing prolonged increases in epithelial permeability. 相似文献
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JH Pruett KB Temeyer WF Fisher PK Beetham SE Kunz 《Canadian Metallurgical Quarterly》1998,35(5):861-871
In this study potential vaccine candidate immunogens were identified and evaluated in a vaccine challenge trial. Calves vaccinated with a partially purified fraction of Psoroptes ovis-soluble proteins had 8 of 14 calves free of palpable lesions 8 wk after a challenge infestation. A self-grooming behavioral response elicited by a pruritic immediate-type allergic reaction was believed to be an effector in protecting the vaccinated calves from a clinical P. ovis infestation. 相似文献
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During the last thirty years there has been a growing interest in research into physician-patient interaction. This article highlights the research which concerns the physician's countertransference feelings. The concept of countertransference is described and a classification with relevance for physicians in general is explained. The existing research into the incidence and consequences of countertransference is examined. Examples are given of categories of patients, who often evoke specific countertransference feelings in the physician. The consequences of the countertransference feelings for the physician himself are discussed and examples are given of particular situations where countertransference feelings could be of importance. Finally, the existing possibilities to learn about handling countertransference feelings are surveyed and the authors emphasize the need for more research in this particular field. 相似文献