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排序方式: 共有814条查询结果,搜索用时 46 毫秒
1.
大气中不同粒径颗粒物诱导人羊膜FL细胞UDS的研究 总被引:3,自引:0,他引:3
本研究以诱导人羊膜细胞UDS为指标,对太原市大气不同粒径的颗粒物提取液进行了致突变性检验,结果表明,不同粒径颗粒物的提取液均可产生一定的遗传毒性,尤以3.3μm以下的颗粒物的遗传毒性较强。 相似文献
2.
David C. Sarrett 《The Journal of prosthetic dentistry》1981,46(2):142-144
A technique has been described for utilizing an existing fixed splint in the fabrication of a fixed partial denture to replace splinted teeth that are extracted. 相似文献
3.
转FL、GM-CSF基因的人骨髓基质细胞促进脐血CD34+细胞体外扩增 总被引:1,自引:1,他引:1
研究转FL、GM-CSF基因的基质细胞对脐血CD34+细胞的扩增效应.将转FL、GM-CSF基因的入骨髓基质细胞系与脐血CD34+细胞共培养,观察细胞总数、CD34+细胞数、CFU-GM的变化情况.培养到第4周时,第(4)组(SCF+IL-3+IL-6+GM-CSF+FL)和第(8)组(HFCL/hGM-CSF+HFCL/hFL+SCF+IL-3+IL-6)的细胞总数增加到最大,分别扩增了717±24.47和709±63.63,第1周,第(5)组(HFCL+SCF+IL-3+IL-6)扩增了10.5±2.08倍,较第(8)组减少(P<0.05).第1周时,CD34+细胞总数第(4)组和第(8)组分别扩增了8.44倍和11.5倍(P<0.05),CD34+细胞百分率第(7)组(FCL/hFL+SCF+IL-3+II,-6)为50.2%,第(6)组(HFCL/hGM-CSF+SCF+IL-3+IL-6)为28.95%(P<0.01).第2周,各组CFU-GM增加显著,以第(4)组和第(8)组增加最为明显,以后随扩增时间延长,造血细胞集落数、集落体积逐渐减少.表明转FL、GM-CSF基因的基质细胞,能有效的协同其他细胞因子对脐血CD34+细胞产生明显的扩增作用,能显著改变基质细胞造血功能. 相似文献
4.
Effects of chemical mediators of anaphylaxis on ciliary function 总被引:2,自引:0,他引:2
Adam Wanner M.D. David Maurer Ph.D. William M. Abraham Ph.D. Zsolt Szepfalusi Marek Sielczak M.D. 《The Journal of allergy and clinical immunology》1983,72(6):663-667
We assessed the effects of selected chemical mediators of anaphylaxis on CBF in vitro. Ciliated epithelial cells were obtained from the trachea of conscious sheep with a cytology brush and suspended in a perfusion chamber containing KH. Ciliary activity was viewed microscopically and recorded on videotape for subsequent slow-motion analysis of CBF. Prostaglandin E1 (10(-8) M to 10(-6) M), prostaglandin E2 (10(-10) M to 10(-6) M), and leukotriene-C4 (10(-8) M) increased CBF between 7% and 33%. Histamine caused ciliostimulation only at the relatively high concentrations above 10(-5) M (7% increase in CBF), whereas prostaglandin F2 alpha (10(-10) M and 10(-6) M) was without effect. In no preparation was ciliary discoordination observed. These findings indicate that several chemical mediators of anaphylaxis stimulate CBF and that the previously described impairment of mucociliary transport in stable allergic asthma or antigen-induced bronchoconstriction is probably not caused by a primary alteration of ciliary function. 相似文献
5.
The density dependence of the maximum expiratory flow-volume curve, functional residual capacity (FRC), and specific airway conductance (SGaw) were determined before and during bronchial provocation with ragweed extract in 27 subjects with ragweed hypersensitivity and a history of either bronchial asthma (16 subjects) or allergic rhinitis (11 subjects). Mean baseline SGaw was significantly lower while mean volume of isoflow (Visov) and FrC were significantly higher in subjects with bronchial asthma. During antigen challenge, 10 of 16 subjects with bronchial asthma (63%) and five of 11 subjects with allergic rhinitis (45%) showed a greater than 35% decrease in SGaw ("reactors"): mean relative decreases in SGaw from baseline were 46% and 53%, respectively. The remaining subjects showed a less than 35% decrease in SGaw ("nonreactors") with mean relative decreases of 9% (allergic asthma) and 6% (allergic rhinitis). Mean Visov increased in all subjects with bronchial asthma and in eight of 11 subjects with allergic rhinitis. A significant increase in FRC (6%) was seen only in the "reactors" with bronchial asthma. Following antigen challenge, the beta adrenergic agonist, isoetharine, increased SGaw and decreased Visov. We conclude that in asymptomatic subjects with ragweed hypersensitivity, (1) central and peripheral airway function is more abnormal in subjects with bronchial asthma than in subjects with allergic rhinitis, (2) subjects of both groups show quantitatively and qualitatively comparable airway responses during antigen challenge with a decrease in SGaw or an increase in Visov, possibly representing increase in central and/or peripheral airflow resistance, respectively, (3) Visov may be a more sensitive indicator of airway response to antigen challenge than SGaw, and (4) the bronchodilator effects of a beta adrenergic agonist on antigen-induced bronchospasm are similar in both groups. 相似文献
6.
目的克隆人Flt3配体(Flt3 LIg and,FL),并在CHO细胞中进行表达。方法从健康人外周血中提取总RNA,通过RT-PCR技术,扩增Flt3配体胞外区cDNA功能性片段,经DNA测序证实后,将得到的片段基因插入pcDNA3.0表达载体,构建了pcDNA3.0-FL真核表达载体;将重组质粒pcDNA3.0-FL转染CHO细胞.经G418筛选出阳性细胞克隆,扩大培养,提取细胞总蛋白,用SDS—PAGE分离并Western blotting检测到在相对分子质量约24000处有一显色条带。结果FL胞外区cDNA被正确克隆到真核表达载体pcDNA3.0中并在CHO细胞中成功表达。结论成功构建了真核表达载体pcDNA3.0-FL并在CHO细胞中成功表达,为FL的相关研究和应用开发奠定了基础。 相似文献
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