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991.
The immune response to a naked plasmid DNA encoding the nucleoprotein (N protein) of porcine transmissible gastroenteritis virus (TGEV) was investigated in this study. A complementary DNA of the entire N gene was amplified by RT-PCR, and inserted into a mammalian expression vector (pcDNA3.1) to construct a recombinant plasmid (pcDNA/N). To evaluate the immunogenicity of the construct, BALB/c mice were intramuscularly immunized with different doses (50, 100 and 200 μg/mouse) of pcDNA/N twice at a 5-week interval. An optimal antibody response was achieved with 100 μg of pcDNA/N. The response lasted at least 11 weeks after primary immunization. By western blotting analysis, the antibodies specifically recognized a 47 kDa protein corresponding to the viral N protein, but they did not reveal neutralizing activity against infectious TGEV in vitro. Immunoglobulin G2a was predominant among these antibodies, which was indicative of Th1 type cell activation in pcDNA/N immunized mice. Moreover, spleen cells from these mice showed stronger immune responses than those from live vaccine or parental vector immunized mice. These results suggest that the construct can elicit both humoral and cell-mediated immune (CMI) responses against TGEV N protein in mice.  相似文献   
992.
Platelet satellitism: experimental studies   总被引:3,自引:0,他引:3  
Platelet satellitism (PS), the in vitro phenomenon of platelets rosetting about nonlymphocytic leukocytes, is an uncommon and poorly understood finding reported in the ethylenediaminetetra-acetic acid (EDTA)-anticoagulated blood of patients with a wide variety of clinical conditions. This report presents experimental studies investigating the nature of this phenomenon by utilizing the blood of patients with platelet satellitism. Wet preparation studies and electron microscopy (transmission and scanning) demonstrated the morphologic sequences involved in the phenomenon, including eventual phagocytosis of platelets by neutrophils. The results of varying conditions such as time, temperature, and anticoagulant are described. All of five patients tested were found to have cryofibrinogenemia. Certain blood components from all of three patients tested were capable of inducing PS in normal whole blood, whereas components from normal subjects usually were not. In one patient (A), the PS-inducing capability appeared to be present in both plasma and platelets. In another patient (B) the PS-inducing capability was present in platelets (in both 1966 and 1975) and also in the cryosupernate of serum and plasma; among various antisera, antifibrinogen had the greatest ability to reduce the degree of PS in patient blood; addition of moderate amounts of CaCl2 and/or MgCl2 did not diminish the phenomenon; and two sisters and two daughters demonstrated no PS. In a third patient (C) the PS-inducing capability appeared to be largely concentrated in the cryoprecipitable fraction of plasma. These studies suggest that there are different factors in the patients' blood resulting in PS. Further studies showed PS could be induced in normal blood by adding certain nonprimate antihuman antisera (anti-IgM, antialbumin or antifibrinogen) and also by adding some preparations of normal washed platelets to the same individuals's normal whole blood. This indicates that the phenomenon of PS can be produced by factors other than those specifically present in patients with PS. Antigen-antibody complexes, either formed in vivo (mixed cryoglobulinemia) or in vitro, did not result in PS when mixed with normal blood. These and other studies suggest that PS can result from the presence of several different factors, usually proteins (in conjunction with EDTA), which probably attach to the surface of platelets apparently resulting in some alteration (such as change in surface charge) causing the platelets to be attracted to and phagocytosed by neutrophils.  相似文献   
993.
目的分析影响医学生人格特征形成的相关因素,为发展大学生的人格特征探寻其理论依据。方法用EPQ量表对601名医学生进行团体测验,其数据在WJZ心理测验软件上预处理后转入电子表格,用SPSS11.0软件进行统计学分析。结果EPQ量表中E、N、P、L的均值、标准差与常模比较,其差异有统计学意义;E,P,L3个维度间有不同程度的相关性:当以EPQ为因变量,15个影响因素为自变量进行逐步回归分析时,进入回归方程的主要是人际关系、家庭、学校教养(育)方式、经济状况、身心伤害否及自我形象、才能、专业的满意度。结论医学生的人格特征还处于发展阶段,其形戍过程与上述因素密切相关。  相似文献   
994.
目的:通过对儿童智商(IQ)与父母亲IQ和IQ分项相关研究,探讨儿童IQ和父母亲IQ的深层关系。方法:在合肥市某中学、小学和幼儿园,分别按年龄和性别分层,随机抽取4-14岁健康儿童206名及其父母作为研究对象,应用韦氏智力量表(成人和儿童)测定儿童和其父母的IQ,填写自编的影响儿童智力发育因素调查问卷。最后在考虑儿童的年龄、性别、克托莱指数(Quetelet index)和是否独生子女等可能混杂因素下将儿童的总IQ、语言IQ和操作IQ与其父母的总IQ、语言IQ、操作IQ和IQ分项进行多元逐步回归分析。结果:按F〉2.0标准,儿童总IQ与父母亲总IQ成正相关(偏相关系数分别为0.50和0.22);儿童语言IQ与母亲算术、母亲知识、父亲算术、父亲拼物成正相关(偏相关系数0.23-0.37);儿童操作IQ和母亲积木图案、母亲拼物和父亲拼物成正相关(偏相关系数0.31-0.50)。结论:父母亲的总IQ和父母IQ分项中的算术、拼物、积木图案和知识等对儿童总IQ、语言IQ和操作IQ影响最大。  相似文献   
995.
活性氧自由基在生物体内参与生理,病理过程并起重大作用,在筛选和评价抗氧化药物时,越来越需要一种快速,简便,价廉而又可靠的抗氧化活性测定方法,本文发展了一种具备了上述优点新方法,SOD(超氧化物歧化酶)及其模拟物的工作已有很多,很多文献报道了其活性一;Cu(Ⅱ)。本文着重研究了另一个金属辅基,Zn^2+并且发现了Zn^2+独特的,但为人们忽视了的;抗氧化活性加强作用。  相似文献   
996.
通过人工合成了人类免疫缺陷性病毒(Humanimmunodeficiencyvirus,HIV)糖蛋白肽GP120对人和无脊椎动物(Mytilusedulis)免疫细胞的抑制作用的研究。人单核细胞和Mytilusedulis免疫细胞分别与GP120保温后,均抑制细胞的吞噬细菌(Psudomonasstretzi)作用。应用计算机显微图像术(Computer-assistedmicroscopy)直  相似文献   
997.
基于"WD倒谱"法分析人体脾组织的超声散射微结构特征   总被引:1,自引:1,他引:1  
本文提出了一种对超声散射信号分析的新方法--“WD倒谱”法,并利用该方法对人体正常脾和脾增生组织的回波信号进行了分析,对软组织中散射子的平均间距进行了估计,结果表明:两种脾组织散射子的平均同距明显不同;“WD倒谱”能有效的反映软组织的微观结构特征,说明“WD倒谱”是软组织超声散射信号分析与软组织散射子平均间距定征的一种有效方法。  相似文献   
998.
The atypical teratoid/rhabdoid tumor, primary to the central nervous system, is a highly malignant and aggressive neoplasm of infancy and childhood. Although having distinct biological features and clinical outcomes, it is frequently misdiagnosed as primitive neuroectodermal tumor/medulloblastoma. To further distinguish the underlying pathogenesis and to identify biological markers for clinical use, an atypical teratoid/rhabdoid tumor-derived cell line was established and its gene expression pattern analyzed in comparison to the human astrocyte SVG12 cell line and the human DAOY medulloblastoma cell line using a complementary DNA microarray method. The osteopontin gene was found specifically upregulated in atypical teratoid/rhabdoid tumor cells. This specificity was confirmed by immunohistochemistry in pathological sections of tissues from atypical teratoid/rhabdoid tumor patients. Even though the role of osteopontin in the cytopathogenesis of atypical teratoid/rhabdoid tumor still needs to be determined, our data support that overexpressed osteopontin is a potential diagnostic marker for atypical teratoid/rhabdoid tumor.  相似文献   
999.
探索采用血管透明化技术结合粒子图像测速技术(PIV)来研究搭桥血管内血流流场的可行性.结果显示血管透明化技术能完整地保留搭桥血管段在体内的真实立体几何构形,从而更准确地反应搭桥血管段在体内的血流流场,而PIV能很好地获得血流流场的信息.因此,将血管透明化技术与PIV相结合有可能使我们对旁路搭桥术后血管内膜增生的血流动力学成因进行更深入地研究.  相似文献   
1000.
根据呼气相胸片中肺部区域灰度较高的特点,通过边缘提取和边缘跟踪确定胸部区域,运用最大类间方差方法确定图像分割的阈值.再提取出肺部区域,然后求出肺部的灰度均值。但这样的结果并不理想。于是在此基础上提出修正方案,即以肺部灰度均值和骨骼灰度均值的比值作为特征值.即比例法。此方法可以较客观的识别呼气相胸片。最后用类间距离对这两种方法进行了量化比较。  相似文献   
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