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991.
介入栓塞治疗用电解脱弹簧圈的电化学研究 总被引:1,自引:0,他引:1
本文研究了用 于介入栓塞颅内 动脉瘤的不锈 钢弹簧圈在 生理盐 水中阳 极溶解 电化 学过程, 确定 了溶断弹簧圈的 电流范围。分析 了不同材料及 表面预处理 对不锈 钢孔蚀 电位的 影响, 为电解 脱离 弹簧圈的选择提 供了依据 相似文献
992.
The objective of this study was to generate and characterize monoclonal antibodies (MAbs) against human airway mucins, and therefore, should serve as a useful tool in studying the regulation of airway mucins in various physiological or pathological situations of human airway. As an antigen, we used a high molecular mass mucin preparation purified from the sputum of normal human subjects. Two monoclonal hybridomas, namely MAbs HM02 and HM03 were obtained and they showed strong immunoreactivity against purified or crude mucin in sputum or bronchial washing of normal human subject. With the high immunoreactivity of these MAbs, mucin contents could be analyzed with more than 100-fold dilution of human airway secretion. The antibodies recognized carbohydrate epitopes because their immunoreactivity was completely abolished by treatment of the mucin with 5 mM periodate. Further characterization of MAbs HM02 and HM03 showed that: (1) they belong to the IgM type; (2) they bind to high molecular mass mucins based on Western blot; (3) they could indirectly immunoprecipitate human airway mucin and as we know, this is the first to demonstrate immunoprecipitation of human airway mucin with anti-human mucin antibodies; and (4) they bind to the goblet cell in airway epithelium as well as some submucosal glands based on immunohistochemistry. Therefore, MAbs HM02 and HM03 should be able to serve as an invaluable tool in studying the regulation of airway mucins in various physiological and pathological situations of human airway. 相似文献
993.
Here we show that suppression of VH-DJH rearrangement in mice bearing a mu heavy (H) chain transgene (mu-tg mice) is associated with an extended period of DH-JH rearrangement, the first step of Immunoglobulin H chain gene rearrangement. Whereas DH-JH rearrangement is normally initiated and completed at the pro-B cell stage, in mu-tg mice it continues beyond this stage and occurs most frequently at the small (late) pre-B stage. Despite ongoing DH-JH rearrangement in late pre-B cells of mu-tg mice, VH-DJH rearrangement is not detectable in these cells. We infer that the lack of VH-DJH rearrangement primarily reflects tg-induced acceleration of B cell differentiation past the stage at which rearrangement of VH elements is permissible. In support of this inference, we find that the normal representation of early B lineage subsets is markedly altered in mu-tg mice. We suggest that the effect of a productive VH-DJH rearrangement at an endogenous H chain allele may be similar to that of a mu-tg; i.e., cells that make a productive VH-DJH rearrangement on the first attempt rapidly progress to a developmental stage that precludes VH-DJH rearrangement at the other allele (allelic exclusion). 相似文献
994.
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996.
目的:利用超声心动图检测正常人左侧房室平面位移幅度。方法:被检对象为144 例正常人,男72 例,女72 例。按不同年龄分为6 组,分别为:Ⅰ组(n= 24 ,3~6 岁);Ⅱ组(n=24 ,7~14 岁) ;Ⅲ组(n=24,15~19 岁) ;Ⅳ组(n= 24,20~39 岁);Ⅴ组(n=24 ,40 ~59 岁) 及Ⅵ组(n= 24 ,≥60 岁)。结果:①左心收缩期房室平面位移测值在Ⅰ组~Ⅴ组之间无显著性差异( P>0-05),而Ⅵ组测值较Ⅰ组~Ⅴ组的测值均低( P< 0-05);②左心收缩期房室平面位移测值不受心率、血压、体表面积及性别的影响。结论:①左侧房室平面位移测值受年龄因素影响;②制定正常左侧房室平面位移测值可以不考虑心率、血压、体表面积及性别的影响 相似文献
997.
采用有机磷化合物对层柱交联累托石催化剂进行了改性研究。考察了有机磷化合物的加入对催化剂轻瓦斯油裂化活性和积炭性能的影响。结果表明:含有适量磷化合物的层柱交联累托催化剂,焦炭产率可降低30%,轻瓦斯油在层柱交联累托石催化剂上的裂化反应和积炭反应是并行的,而裂化活性仍保持不变。磷化合物的加入使层柱交联累托石催化剂的B酸强度增加,但积炭反应主要不是由B酸强度决定,而是与强弱B酸中心数目的比例以及B酸和L 相似文献
998.
RATIONALE AND OBJECTIVES: To evaluate the short-term effects of a new nitinol stent on canine arteries. METHODS: Eighteen nitinol mesh stents were placed in abdominal aortas, common iliac arteries, and renal arteries of six dogs. Angiography was performed to evaluate the patency rates and structural changes of arteries at 1 day, 3 weeks, 4 weeks, and 10 weeks after stent insertion. Gross and light microscopic examinations were performed after angiography. RESULTS: On angiography, the patency rate was 100%, and no thrombosis was observed. All side branches from stented segments were patent. The mean neointimal thickness over and between stent wires was 94 and 167 microns. No difference was found between the aorta and the small vessels. Histologically, the neointima was covered with endothelium and was composed of subintimal fibrosis with mild inflammation. CONCLUSIONS: The new type of nitinol mesh stent showed a high patency rate, with no thrombosis and relatively thin neointimal proliferation. 相似文献
999.
This study assessed 11C-acetate turnover (clearance) in nasopharyngeal carcinoma (NPC). Data were acquired by dynamic PET after the intravenous injection of 4.625 MBq.kg-1 body weight of 11C-acetate for 30 min. Tomograms were reconstructed and evaluated visually. A time-activity curve of the nasopharynx and neck was generated and the clearance rate of 11C-acetate from the nasopharynx in the slow phase and from NPC was calculated using 0.693/T1/2. Ten patients with nasopharyngeal carcinoma and nine normal subjects were studied. The clearance of 11C-acetate from the normal nasopharynx was rapid and biexponential, in contrast to the rapid uptake followed by extremely slow clearance in patients with NPC. The clearance rate (mean +/- S.D.) was 0.0074 +/- 0.0042 in NPC and 0.0263 +/- 0.0152 in controls in the slow phase, being significantly different between the two groups with no overlap. All nasopharyngeal carcinomas were clearly visualized, in contrast to no obvious retention in the normal nasopharynx. Our initial results indicate that 11C-acetate clearance can be used to differentiate nasopharyngeal carcinoma from a normal nasopharynx. This finding may lead to new applications of 11C-acetate in oncology. 相似文献
1000.
Intracranial germinomas: correlation of imaging findings with tumor response to radiation therapy 总被引:9,自引:0,他引:9
OBJECTIVE: The purpose of this study was to correlate imaging characteristics of intracranial germinomas with response to radiation therapy. MATERIALS AND METHODS: Using tumor size at the completion of irradiation, we classified 23 patients with histologically proven germinomas in the pineal gland (n = 6), the suprasellar region (n = 7), and the basal ganglia (n = 10) into two groups: excellent response group (n = 14) and good response group (n = 9). Excellent response was defined as complete resolution or residual tumor less than 1.0 cm in diameter, and good response was defined as residual tumor of 1.0-3.0 cm in diameter. CT (n = 53) and MR (n = 32) images obtained before, during, and after radiation therapy were retrospectively analyzed with particular attention to the location, size, presence of cystic change, and CSF seeding of the tumors. RESULTS: In all 23 patients, the tumors decreased 85-100% in size at the completion of irradiation with 40-56 Gy. A significant factor in the different responses to irradiation between patients in the excellent and good response groups was cystic change of the tumor. Tumors with cystic components responded more slowly and had larger residual lesions than did tumors without cystic components (p < .01). In eight of 12 cystic tumors, the cystic portion of the tumor responded more slowly than did the solid portion and remained visible on imaging 6-12 months after irradiation. We found no significant differences between the two groups in location, size, and CSF seeding of tumors. In 12 patients with residual lesions at the completion of irradiation, the tumors proceeded to resolve after completion of treatment. CONCLUSION: In our study, tumor response to radiation therapy correlated negatively with the presence of a cystic region. 相似文献