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41.
Pairs of sequential perfusion lung scans and pulmonary angiograms obtained in 45 patients were reviewed to investigate the utility of short-term, sequential scintigraphy in the diagnosis of pulmonary embolism (PE). Forty-six sequential scan pairs were reviewed; 13 were ventilation-perfusion (V-P) pairs. Angiograms were obtained within 48 hours of either the first (65%) or second (35%) perfusion scan in each pair. Sequential scintigraphic patterns were classified as showing change (i.e., improvement in defects, new defects), no change, or as being indeterminate. A changing perfusion pattern was associated with a high (20/23) likelihood of PE, but seven of 16 patients with stable perfusion patterns also had PE. The sensitivity of a changing perfusion pattern for PE was 0.74 (20/27) and its specificity was 0.75 (9/12). In two of six patients who had serial V-P studies that showed changing perfusion defects, there were matched changes in regional ventilation and angiograms were negative. The findings suggest that short-term serial perfusion lung scanning may aid the scintigraphic diagnosis of PE in certain circumstances. Serial V-P imaging is needed, however, to maximize diagnostic specificity. 相似文献
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燃煤烟道蜂窝净化剂除氟效果的研究 总被引:2,自引:1,他引:2
针对中国燃煤污染氟中毒分布范围广病情严重的特点,在民用炉灶烟道内装入蜂窝状净化剂除氟措施的可行性进行了初步的探讨。其中对蜂窝状净化剂的材料配比、孔径大小、长度、吸附容量、安装方法的堵塞问题进行了较详细的实验。在现场进行了除氟效果的验证、实验结果表明,烟道内装入蜂窝状净化剂除氟效率为89.1%,同时对煤烟中的SO2也有一定的去除效果,除硫率为53.6%。此项措施与改炉改灶措施结合推广运用,将有助于燃煤氟硫污染问题的解决。 相似文献
44.
Predictors and Characteristics of Multiple (More Than 2) Catheter Ablation Procedures for Atrial Fibrillation 下载免费PDF全文
45.
The role of endothelium in the inhibition of human factor Xa was studied in a plasma environment. Human factor Xa can bind to and function on bovine aortic endothelium in a manner similar to that of bovine factor Xa. Approximately 70% of the bound factor Xa is subject to inhibition by plasma proteinase inhibitors, and the remaining 30% is irreversibly bound as part of a 125 Kd membrane-associated complex not subject to proteolytic degradation. The proportion reversibly bound and its rate of release do not alter with changes in calcium, citrate, heparin, or active proteinase inhibitor concentrations. The principal plasma proteinase inhibitor of human factor Xa was antithrombin III, which accounted for 60% to 65% of factor Xa released from endothelium, with alpha 1-proteinase inhibitor inactivating 20% to 25% and alpha 2- macroglobulin approximately 15%. All of the reversibly bound factor Xa was identified in complex with one of these three proteinase inhibitors. The thrombin active-site inhibitor hirudin was found to markedly accelerate the displacement of reversibly bound factor Xa from the endothelium and to associate specifically with factor Xa without a loss of activity toward chromogenic substrates, perhaps accounting for a novel mechanism of anticoagulation. 相似文献
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SUNNY S. PO M.D. Ph .D. HIROSHI NAKAGAWA M.D. Ph .D. WARREN M. JACKMAN M.D. 《Journal of cardiovascular electrophysiology》2009,20(10):1186-1189
Background. The intrinsic cardiac autonomic nervous system (ICANS), which forms a neural network, has been shown to be a critical element responsible for the initiation and maintenance of atrial fibrillation (AF). We developed a technique to localize and ablate the ganglionated plexi (GP), which serves as the "integration centers" of the ICANS.
Method. The four major atrial GP are localized by delivering high frequency stimulation (HFS; 20 Hz, 10–150 V, 1–10 ms pulse width) to atrial tissue where GP are presumed to be located. Sites showing a parasympathetic response, which is arbitrarily defined as ≥50% increase in mean R-R interval during AF, was assigned as a GP site. Radiofrequency current is then applied to that site to eliminate the parasympathetic response. All patients received ablation of the four major atrial GP, followed by pulmonary vein antrum ablation.
Results. Our preliminary results showed that all the four major atrial GP can be identified in the vast majority of patients. The parasympathetic response can be eliminated by applying radiofrequency current. In the first 83 patients, the percent of patients free of symptomatic AF or atrial tachycardia after a single ablation procedure was 80% at 12 months and 86% at a mean follow-up of 22 months.
Conclusion. These results indicate additional benefits of GP ablation to PV antrum ablation and improvement with time, particularly ≥ 12 months after ablation. We postulate that this late benefit may result from destruction of the autonomic neurons in the GP that cannot regenerate. 相似文献
Method. The four major atrial GP are localized by delivering high frequency stimulation (HFS; 20 Hz, 10–150 V, 1–10 ms pulse width) to atrial tissue where GP are presumed to be located. Sites showing a parasympathetic response, which is arbitrarily defined as ≥50% increase in mean R-R interval during AF, was assigned as a GP site. Radiofrequency current is then applied to that site to eliminate the parasympathetic response. All patients received ablation of the four major atrial GP, followed by pulmonary vein antrum ablation.
Results. Our preliminary results showed that all the four major atrial GP can be identified in the vast majority of patients. The parasympathetic response can be eliminated by applying radiofrequency current. In the first 83 patients, the percent of patients free of symptomatic AF or atrial tachycardia after a single ablation procedure was 80% at 12 months and 86% at a mean follow-up of 22 months.
Conclusion. These results indicate additional benefits of GP ablation to PV antrum ablation and improvement with time, particularly ≥ 12 months after ablation. We postulate that this late benefit may result from destruction of the autonomic neurons in the GP that cannot regenerate. 相似文献
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Diabetes mellitus in Danish cystic fibrosis patients: prevalence and late diabetic complications 总被引:1,自引:0,他引:1
S Lanng B Thorsteinsson C Lund-Andersen J Nerup PO Schiøtz C Koch 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(1):72-77
Lanng S, Thorsteinsson B, Lund-Andersen C, Nerup J, Schiatz PO, Koch C. Diabetes mellitus in Danish cystic fibrosis patients: prevalence and late diabetic complications. Acta Pzdiatr 1994;83: 72–7. Stockholm. ISSN 0803–5253.
The prevalences of impaired glucose tolerance (IGT), diabetes mellitus and late diabetic complications were studied in all Danish cystic fibrosis (CF) patients. A total of 311 CF patients were identified with an estimated ascertainment rate above 98%. Glucose tolerdnce was classified in 278 (89%) patients: the prevalences of IGT and diabetes mellitus were 13.7% (38 patients) and 14.7% (41 patients), respectively, with no sex differences. The prevalence of diabetes mellitus increased with age but not with the severity of CF as compared with age- and sex-matched non-diabetic CF patients. Diabetes was diagnosed at a median age of 20 years (range 3–40 years) and the duration of diabetes was 1.7 years (0.1–17 years). Twenty-eight of the diabetic patients (70%) were trcated with insulin, on average 20 (4–90) IU per day. Late diabetic complications were identified in 4 patients (10%) with a duration of diabetes mellitus of 1–17 years: background retinopathy (2 patients), diabetic nephropathy (1 patient), microalbuminuria (1 patient) and neuropathy (2 patients). Thus diabetic CF patients are probably not less prone to develop late diabetic complications than patients with other types of diabetes of equally long duration and comparable glycemic control. 相似文献
The prevalences of impaired glucose tolerance (IGT), diabetes mellitus and late diabetic complications were studied in all Danish cystic fibrosis (CF) patients. A total of 311 CF patients were identified with an estimated ascertainment rate above 98%. Glucose tolerdnce was classified in 278 (89%) patients: the prevalences of IGT and diabetes mellitus were 13.7% (38 patients) and 14.7% (41 patients), respectively, with no sex differences. The prevalence of diabetes mellitus increased with age but not with the severity of CF as compared with age- and sex-matched non-diabetic CF patients. Diabetes was diagnosed at a median age of 20 years (range 3–40 years) and the duration of diabetes was 1.7 years (0.1–17 years). Twenty-eight of the diabetic patients (70%) were trcated with insulin, on average 20 (4–90) IU per day. Late diabetic complications were identified in 4 patients (10%) with a duration of diabetes mellitus of 1–17 years: background retinopathy (2 patients), diabetic nephropathy (1 patient), microalbuminuria (1 patient) and neuropathy (2 patients). Thus diabetic CF patients are probably not less prone to develop late diabetic complications than patients with other types of diabetes of equally long duration and comparable glycemic control. 相似文献
50.