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排序方式: 共有715条查询结果,搜索用时 31 毫秒
1.
目的 通过临床与实验研究选择合适的皮片游离移植手术包扎材料.方法 实验分别以软质聚氨酯泡沫塑料、层叠干纱布、松散干沙团和干棉花团为测试包扎材料.分别在测试包扎材料上加压,记录血浆袋所受到的压力和包扎材料厚度压缩比例的变化;临床常规方法片皮移植,以软质聚氨酯泡沫塑料块加压包扎皮片.结果 软质聚氨酯泡沫塑料当外加压力使其压缩至原厚度的90%~34%时,可使皮片受到25 cmH2O~54.4 cmH2O的压力;此压力范围足以使皮片与创面密切接触,保证皮片成活,又避免过大的压力影响皮片血供重建.以软质聚氨酯泡沫塑料为包扎材料植皮,皮片成活率明显提高.结论 软质聚氨酯泡沫塑料是一种良好的植皮包装材料. 相似文献
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3.
One of the advantages of polyurethane foam-covered prostheses has been that in the first 5 to 10 years after their use, the
amount of capsular contraction was found much less than when similar ``slick' prostheses were used. Another advance was their
fixation to the surrounding tissue thus giving a more natural appearance and movement with the muscles when the arms were
moved in any direction. The formation of a thick capsule also acted as a protection against gel granuloma due to rupture of
the prosthesis and has been thought to be a factor in the lower capsule contraction rate. The greatest disadvantage has been
that its removal was extremely difficult and this has continued up until the technique described in this paper has been introduced. 相似文献
4.
Jan Lycke Bo Svennerholm Anders Svenningsson Walter Muranyi Rolf M. Flügel Oluf Andersen 《Journal of neurology》1994,241(4):204-209
The role of human spumaretrovirus (HSRV) infections in the pathogenesis of multiple sclerosis (MS) was investigated with recombinant HSRV env-specific enzyme-linked immunosorbent assay. The presence of HSRV antibodies was determined in pairs of serum and cerebrospinal fluid (CSF) samples from 60 MS patients. In 7 of these patients serial serum and CSF samples were obtained in relation to the clinical activity of the disease during a period of 2 years. No increased antibody reactivity was demonstrable in the MS population compared with 14 aseptic meningitis patients, 50 blood donors and 16 healthy controls. Slightly elevated levels of antibodies were demonstrable in serum and/or CSF in 4 MS patients but also in 1 patient with aseptic meningitis, 1 blood donor and 1 child. No marked serum or CSF HSRV antibody fluctuation was observed in the MS patients followed longitudinally. Thus, this study does not support the involvement of HSRV in the pathogenesis of MS. 相似文献
5.
Summary A pathologic study was undertaken of seven encephalic arteriovenous malformations, including five resected from one to seven days after balloon embolization, one resected 10 days after embolization with polyvinyl alcohol foam (PVA), and a large mesencephalic AVM in a patient who died eight weeks after a series of embolization procedures with PVA and silicone spheres. AVM's resected 6–7 days following balloon embolization showed focal mural and adventitial inflammatory infiltrates and parenchymal (i.e. non-vascular) necrosis of a large portion of one AVM. The AVM examined 7 days post-balloon embolization showed an intraluminal thrombus containing refractile particles surrounded by foreign body giant cells (FBGC's). The AVM removed 10 days after PVA embolotherapy showed mural and perivascular necrosis with infiltration by polymorphonuclear leukocytes. The single autopsy case showed FBGC's surrounding residual PVA, refractile particles deep within vascular walls, and marked mural thickening of AVM channel walls, changes that may represent a response to previous angionecrosis and inflammation at the time of embolization. These findings, the pathogenesis of which is discussed in detail, may help to explain some of the rare complications of iatrogenic embolotherapy with these materials, as well as providing evidence for the basis of their efficacy.Presented in part at the 63rd Annual meeting of the American Association of Neuropathologists, Seattle, Washington, June, 1987 相似文献
6.
In order to investigate the role of monocyte/macrophages and their relationship to the expression of macrophage colony-stimulating factor (MCSF) in pulmonary atherosclerosis, lungs were excised from rabbits that had been fed for 60 and 90 days on a diet containing 0.5% cholesterol. In the lungs, fatty streaks and elevated foam cell lesions predominated in the large or medium-sized elastic pulmonary arteries, while massive accumulation of foam cells in the intima of muscular arteries produced marked luminal narrowing and nearly complete occlusion. In these lesions, most of the foam cells were reactive with RbM2, a monoclonal antibody (mAb) against rabbit macrophages, while smooth muscle cell-derived foam cells were detected by mAb against smooth muscle actin in the deeper area of elevated foam cell lesions of elastic arteries. Ultrastructural observation confirmed the presence of monocytes in the intima, their differentiation into macrophages, and their transformation into foam cells in the atherosclerotic lesions. lmmunohistochemical expression of MCSF was demonstrated in the endothelial cells, smooth muscle cells and foam cells. A minor macrophagederived foam cell population was demonstrated to possess a prolif-erative capacity. These data suggest that MCSF is involved in the differentiation of monocytes into macrophages, their transformation into foam cells, and their proliferation during pulmonary atherogenesis. 相似文献
7.
目的:探讨肺炎衣原体( Cpn) 促进 C57 B L/6 J 小鼠腹膜巨噬细胞泡沫化的机制。方法:取 C57 B L/6 J小鼠腹膜巨噬细胞培养24 h 让其贴壁后分为对照组、 L D L 组和 L D L 加 Cpn 组3 组培养,然后测反应液中自由基、 M D A 及 S O D 含量。结果:反应液中自由基、 M D A、 S O D 含量 L D L 加 Cpn 组比 L D L 组高,存在显著性差异。结论:脂质过氧化是肺炎衣原体促进巨噬细胞泡沫化的机制之一。 相似文献
8.
马齿苋抗家兔主动脉泡沫细胞形成机制的探讨 总被引:5,自引:0,他引:5
目的 探讨马齿苋抗家兔主动脉泡沫细胞形成的作用机制 ,研究影响动脉粥样硬化 (AS)形成的有关因素。方法 动物分为 4组 ,A、B、C 3组建立动物高脂模型 ,B、C组分别喂饲马齿苋干粉 8或 12g/ (d·只 ) ,实验 11周末 ,采血测定血脂、丙二醛、血液粘度等指标并观察透射电镜下主动脉内膜病理改变。用多元逐步回归分析 ,筛选影响AS形成的主要因素。结果 B、C组与A组相比 ,血清总胆固醇 (TC)、甘油三脂 (TG)、丙二醛 (MDA)、全血低切表观粘度、血浆中切表观粘度水平明显下降 (P <0 0 1) ;高密度脂蛋白胆固醇 (HDL -C)明显上升 (P <0 0 1) ,C组TC、全血低切表观粘度数值较B组明显降低 (P <0 0 1)。多元方程显示α =0 0 5,0 0 1时对Y有显著影响的是TC(X1) ,血浆中切表观粘度 (X6 )。结论 马齿苋可明显阻止或降低血清TC、TG、MDA、全血低切及血浆中切表观粘度的升高 ,并升高HDL -C ,随着剂量的增加 ,马齿苋作用增强。电镜观察显示马齿苋能使主动脉内膜泡沫细胞数目减少 ,脂质沉积减轻 ,抑制AS斑块形成。多元分析表明 ,影响主动脉AS形成的主要因素是TC及血浆中切表观粘度 ,二者皆为正向影响 ,且TC影响最大。试验显示 ,马齿苋降低该两项因素的作用最为明显 相似文献
9.
胆固醇酯蓄积的巨噬细胞(泡沫细胞)是早期动脉粥样硬化斑块的主要组成和特征。它通过其细胞表面的多种受体无限制地摄取氧化型低密度脂蛋白(ox-LDL)颗粒及其他配体,结果在巨噬细胞内有大量的胆固醇酯和三酰甘油蓄积,使巨噬细胞发展成为泡沫细胞。因此,通过各种途径抑制这种在巨噬细胞的过量脂质蓄积,可以起到预防和治疗动脉粥样硬化的作用。 相似文献
10.
In this study, a novel, dynamic model of a graphene-platelet-reinforced, porous (GPLRP) double-cylindrical-panel system is proposed. The material properties of a graphene-platelet-reinforced, porous, double-cylindrical-panel system were determined by the Halpin–Tsai micromechanics model and the typical mechanical properties of open-cell metal foams. Different types of porosity distribution and graphene platelet (GPL) distribution patterns were considered. Love’s shell theory was utilized to derive the theoretical formulation, and the Rayleigh–Ritz method was used to calculate the natural frequencies of the system. The proposed model was validated by several comparison studies with the natural frequencies in the existing literature. Finally, the effects of stiffness of Winkler springs, boundary condition, porosity coefficient, porosity distribution, GPL distribution pattern, and GPL weight fraction on the free vibration characteristics of the system were evaluated. 相似文献