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911.
Normal dystrophin transcripts detected in Duchenne muscular dystrophy patients after myoblast transplantation. 总被引:26,自引:0,他引:26
E Gussoni G K Pavlath A M Lanctot K R Sharma R G Miller L Steinman H M Blau 《Nature》1992,356(6368):435-438
912.
Tumour necrosis factor alpha restores granulomas and induces parasite egg-laying in schistosome-infected SCID mice. 总被引:38,自引:0,他引:38
P Amiri R M Locksley T G Parslow M Sadick E Rector D Ritter J H McKerrow 《Nature》1992,356(6370):604-607
Schistosomiasis (bilharzia) is a parasitic disease caused by several species of schistosome worms (blood flukes). The key pathogenic event in this disease is the formation of granulomas around schistosome eggs trapped in portal venules of the liver. Granulomas are a distinctive form of chronic inflammation characterized by localized aggregation of activated macrophages around an inciting stimulus. Each granuloma evolves to form a fibrous scar; in schistosomiasis, the result is widespread hepatic fibrosis and portal hypertension. To identify the specific immune signal molecules necessary for granuloma formation, we studied schistosome infections in severe combined immunodeficient (SCID) mice, which have normal macrophages but lack functional B or T lymphocytes. Here we report that the immunoregulatory cytokine tumour necrosis factor alpha is necessary and sufficient to reconstitute granuloma formation in schistosome-infected SCID mice. Moreover, we find that the parasitic worms require tumour necrosis factor alpha for egg-laying and for excretion of eggs from the host. The implication of this latter result is that the parasite has adapted so successfully to its host that it uses a host-derived immunoregulatory protein as a signal for replication and transmission. 相似文献
913.
D J Roberts A G Craig A R Berendt R Pinches G Nash K Marsh C I Newbold 《Nature》1992,357(6380):689-692
Adhesion of parasitized erythrocytes to post-capillary venular endothelium or uninfected red cells is strongly implicated in the pathogenesis of severe Plasmodium falciparum malaria. Neoantigens at the infected red-cell surface adhere to a variety of host receptors, demonstrate serological diversity in field isolates and may also be a target of the host-protective immune response. Here we use sequential cloning of P. falciparum by micromanipulation to investigate the ability of a parasite to switch antigenic and cytoadherence phenotypes. Our data show that antigens at the parasitized cell surface undergo clonal variation in vitro in the absence of immune pressure at the rate of 2% per generation with concomitant modulations of the adhesive phenotype. A clone has the potential to switch at high frequency to a variety of antigenic and adhesive phenotypes, including a new type of cytoadherence behaviour, 'auto-agglutination' of infected erythrocytes. This rapid appearance of antigenic and functional heterogeneity has important implications for pathogenesis and acquired immunity. 相似文献
914.
本文给出了一个在传统转速电流双闭环基础上增加锁相环路构成的直流调速系统。该系统具有稳定性好,稳态精度高,调速范围宽的优点。文中给出了系统的稳定性分析及参数设计方法。 相似文献
915.
本文的实验结果表明,具有开放型本征构型的La_2O_3对甲烷氧化偶联反应有相当好的活性和选择性,在750℃、原料气空速6.O×10~4ml.g~(-1).h~(-1),CH_4:O_2:N_2=3.7:l.0:9.0(V/V)的反应条件下,氧接近全部转化,甲烷转化率达25.4%,C_2烃选择性为43.6%,添加碱土金属(Ca、Sr、Ba)氧化物或碳酸盐能显著地改善催化剂的性能,在上述反应条件下,60mol%Ba-La_2O_3催化剂的C_2烃选择性达到58%。 相似文献
916.
黑曲霉(Aspergillusniger728)的粗酶液,经硫酸铵沉淀,SephadexG-25柱凝胶过滤脱盐,DEAE-Toyopearl离子交换柱层析和SephacryS-100凝胶层析纯化,经PAGE鉴定为一条带SDS凝胶电泳测定分子量为70000.金属离子Fe3+对该酶有一定的抑制作用,该酶的等电点为3.7,最适pH为4,最适温度为60℃.E2801%为15.72,Km值为0.112×10-3m. 相似文献
917.
建筑火灾综合模拟评估在大空间建筑火灾中的初步应用 总被引:4,自引:0,他引:4
运用火灾规律双重性理论,探讨建筑火灾综合模拟评估的理论框架,以影院会堂类大空间建筑为例,运用一些可调试的模拟方法、统计分析及其模型,给出在火灾评估具体环节和应用程式上的一定程度的量化描述.实现火灾综合模拟评估理论模型的可操作性,使更进一步准确和方便地估算建筑火灾对人员、财产造成危害的几率,和判断这种危害的发生具备了初步的可能. 相似文献
918.
Ehrlich carcinoma and EL-4 thymoma ascites cells were subjected in vitro to heat shock, ATP depletion, oxidative stress, Ca2+ overlading and iodoacetamide treatment. After the transient stresses, Triton (X-100)-insoluble TIS) fractions were isolated from the cells and analysed by electrophoresis and immunoblotting. All stresses used caused rapid aggregation of cell proteins. This was manifested in a signficant rise in protein content in the TIS fractions. The protein increase was mostly due to and increase in the insolubility of actin, 57 kDa protein of intermediate filaments, 70 kDa heat shock protein (HSP 70), and some specific proteins whose insolubilization was a characteristic sign for each type of cell injury. Different survival rates in the cell lines after either stress corrlated well with differences in their TIS protein accretion. Possible mechanisms for stress-induced protein aggregation and its relationship with cell viability are suggested. 相似文献
919.
Treatment with the co-transport inhibitor, furosemide decreased36Cl– flux across perfused Malpighian tubules ofLocusta. However, exclusion of36Cl– from the bathing medium had not effect on22Na+ flux whereas substitution of bathing medium Na+ by K+ increased36Cl– flux. Diuretic extract of corpora cardiaca increased22Na+ (by 106%) and36Cl– (by 335%) fluxes differentially. 相似文献
920.
R. J. Capon K. Elsbury M. S. Butler C. C. Lu J. N. A. Hooper J. A. P. Rostas K. J. O'Brien L. -M. Mudge A. T. R. Sim 《Cellular and molecular life sciences : CMLS》1993,49(3):263-264
The Antarctic marine spongeTedania charcoti has been shown to contain extraordinarily high natural concentrations of cadmium and zinc, which have in turn been correlated to the ability of the crude ethanol extract to modulate protein phosphorylation in chicken forebrain and to inhibit the growth of several test bacteria. 相似文献