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1.
Cultured cells derived from male patients with Burkitt's lymphoma and harboring herpes-type virus particles were lethally irradiated. These irradiated cells induced normal peripheral leukocytes of female infants to grow within 2 to 4 weeks after mixed cultivation. Cells of a line free of this agent failed to stimulate growth. If either type of cell was cultured separately, it did not survive under the experimental conditions. Herpes-type viral antigen and C-group chromosomal marker previously described in cultured Burkitt cells were found in all of the female cell cultures that were obtained.  相似文献   

2.
STEERE RL 《Science (New York, N.Y.)》1963,140(3571):1089-1090
End-to-end aggregation of tobacco mosaic virus and associated particles during extraction and purification may be prevented by transfer of the virus to 0.001M buffer solution of ethylenediaminetetraacetic acid, pH 7.5, as rapidly as practicable. Colored components were removed with charcoal and diatomaceous earth, and salts by rapid passage through a column of granulated 8 percent agar gel. The virus particles were sorted according to length by passage through a 1 percent granulated agar-gel column to isolate the 300- and 200-mmicro fractions and through a 5 percent agar gel to isolate the shorter particles.  相似文献   

3.
The malting barley-producing regions in Montana and Canada are threatened with a new virus-like barley disease that appears to be etiologically novel. Ultrathin sections of diseased tissue contained enveloped, filamentous virus-like particles that measured 64 nanometers by 126 to 4000 nanometers. These lengths are unique for plant viruses. Unexpectedly, the spider mite,Petrobia latens, which has never been reported to be a vector of a pathogen, was found to transmit the causal agent from diseased plants to healthy barley, while noninfective mites failed to do so unless they were allowed prior access to diseased tissue.  相似文献   

4.
Pentagonal aggregation of virus particles   总被引:1,自引:0,他引:1  
Virus aggregates with a unique fivefotd axis have been observed in the electron microscope.  相似文献   

5.
A mutualistic association between a fungal endophyte and a tropical panic grass allows both organisms to grow at high soil temperatures. We characterized a virus from this fungus that is involved in the mutualistic interaction. Fungal isolates cured of the virus are unable to confer heat tolerance, but heat tolerance is restored after the virus is reintroduced. The virus-infected fungus confers heat tolerance not only to its native monocot host but also to a eudicot host, which suggests that the underlying mechanism involves pathways conserved between these two groups of plants.  相似文献   

6.
Infection by hepatitis B virus(HBV) results in acute and chronic liver damages in humans. Liver products of broilers as a primary food consumed in our daily life have a close connection with public health. The prevalence of the virus in livers and serum of broilers is of great significance, owning to the potential transmission between chickens and humans. Liver tissues and serum samples were tested to investigate the prevalence of hepatitis B virus infection in slaughtered broilers, for expression of HBV antigens and antibodies. The distribution and positive rate of hepatitis B surface antigen(HBs Ag), hepatitis B core antigen(HBc Ag) and hepatitis B e antigen(HBe Ag) in liver samples were examined using immunohistochemistry. HBs Ag was mainly located in the cytoplasm of hepatocytes with a positivity of 81.61% whereas HBe Ag and HBc Ag were primarily located in the nucleus of hepatocytes with a positivity of 40.13 and 49.10%, respectively. Enzyme-linked immunosorbent assay(ELISA) analysis of serum for HBV serological markers demonstrated a high prevalence of hepatiits B surface antibody(HBsA b, 54.91%) and hepatitis B core antibody(HBcA b, 27.68%), whereas HBeA b, HBsA g and HBeA g were rarely detectable. Classic hepatitis pathological changes, including swollen hepatocytes, focal parenchymal necrosis, lymphocytic infiltration and hyperplasia of fibrous connective tissues were observed using histopathological analysis. Some of the liver samples were found positive for HBV DNA using nested PCR. Sequence comparison confirmed that all sequences shared 97.5–99.3% identity with human HBV strains. These results demonstrated the existence of HBV in livers and serums of broilers. Animals or animal products contaminated with HBV could raise an important public health concern over food safety and zoonotic risk.  相似文献   

7.
Electron microscopy of small perivenous demyelinating lesions in a formalin-fixed brain of a multiple sclerosis subject revealed nuclear and cytoplasmic particles resembling paramyxovirus nucleocapsids. These particles, 18 to 20 nanometers in diameter, were found in mononuclear cells related to the central vein and infiltrating the zone of active demyelination. It is suggested that multiple sclerosis lesions may be initiated by seeding of lymphocytes bearing latent paramyxovirus to white matter of the central nervous system.  相似文献   

8.
Smut is a serious disease in Job's tears, also known as adlay, and contributes to the reduction of crop yield in agricultural fields. In this study, the key pathogenic fungi in adlay smut disease were first identified by internal transcribed spacer region(ITS) high-throughput sequencing and then used to elucidate the composition and diversity of the fungal community in adlay smut. Results indicate that an abundance of operational taxonomic units(OTUs) were detected in the infected involucres of flowering plants and the OTUs were classified to nine phyla, 20 classes, 45 orders, 90 families and 119 genera. A total of 4 986 OTUs clustered together, sharing six core OTUs in all samples, while 145 OTUs were shared among four geographical groups. The Shannon and Simpson indices ranged from 0.137–1.629 and 0.357–0.970, respectively. Community diversity ranked as Anshun(AS)Qinglong(QL)Xingren(XR)Xingyi(XY) among the four geographical groups by Shannon and Simpson indices, exhibiting complex community diversities among accessions and geographical groups. The richness and diversity data imply a weak relationship between the accession community richness and geographical origins of samples. Two closely related fungal genera, Sporisorium and Ustilago, were implicated as causes of smut disease. The genus Sporisorium appears to be more commonly found among accessions and thus is more likely to be the fungal pathogen causing smut in adlay. This work can facilitate strategies to control and prevent smut infection to improve adlay yield.  相似文献   

9.
云南半帚孢 (Leptographiumyunnanense)是云南松纵坑切梢小蠹携带的一种主要的病原性伴生真菌 .以PD培养液对该菌进行培养 ,培养滤液即毒素原液中蛋白部分具致病活性 ,在冷藏及室温条件下 ,该毒素能较长时间 (2 0~ 40d)保持致病活性 (即能在寄主树木上形成一定长度的韧皮反应区 ) ,随着温度的升高 ,其活性逐渐丧失 ;在 6 0℃时 ,该毒素仍可保持一定的活性 ,而在超过 80℃时 ,则完全丧失其活性 .毒素原液pH值为 5 1,渗透势为 - 12 0kPa ,经试验确定毒素原液的毒性非溶液的酸度或渗透势所致 ,从而表明该菌培养液中存在具致病活性的毒素物质 .  相似文献   

10.
从云南元谋表现黄脉症状的杂草赛葵上分离到一病毒分离物Y200.对其DNA-A基因组部分序列测定分析表明,该序列与赛葵黄脉病毒Malvastrum yellow vein virus(MYVV)相应序列的同源性为96.1%.利用DNAβ的特异性引物,从Y200中扩增到卫星DNA分子.序列分析表明,该DNAβ全长1348个核苷酸,全序列与MYVV DNAβ的同源性最高,为96.1%.DNA-A部分序列和DNAβ全长序列分析表明,该病毒分离物为MYVV.  相似文献   

11.
12.
应用改进的十二烷基硫酸钠 -聚丙烯酰胺凝胶电泳 (SDS- PAGE)方法从感染柑橘速衰病毒 (CTV)强株系和弱株系的墨西哥酸橙病株中检测到一种相对分子质量约为 130 0 0的特异蛋白 ,而在健株中未能检测到 ,该蛋白电泳谱带没有差异 .应用 Western印迹技术进一步分析表明 ,这种蛋白不与 CTV特异的多克隆抗体10 52和 3DF1单克隆抗体反应 .这暗示着该蛋白是墨西哥酸橙在 CTV侵染胁迫条件下编码产生的一种病程相关蛋白 .研究结果也表明 ,应用 SDS- PAGE方法检测这一特异蛋白 ,可作为诊断墨西哥酸橙植株感染 CTV的一种有效的分子生物学辅助检测方法  相似文献   

13.
Neuronal vacuolation and intravacuolar budding of vesicles and cytoplasmic processes appear to be the most characteristic cellular lesion in natural scrapie, a chronic degenerative disease of the central nervous system of sheep which is transmissible by injection. Membrane-bound accumulations of the 35-nm particles are fotnd in the cytoplasmic processes that project inside the vacuoles of the neuronal perikaryon. Such particles are present only in a small number of vacuolated neurons.  相似文献   

14.
Plants infected with a necrotic strain of turnip yellow mosaic virus contain tubes averaging about 80 millimicrons in diameter and attaining 3 microns in length. The main constituent of these tubes is a protein that is related chemically and immunologically to the protein of the virus. The tubes are composed of hexagonally packed hexagonal subunits resembling the hexamer protein subunits of the virus particles and are probably helical in construction.  相似文献   

15.
KLA 16 virus, recovered from a child with Thailand hemorrhagic fever, produces infant mouse, rat, and hamster disease that is characterized by spontaneous bleeding at multiple sites, notably in the gastrointestinal tract, and by marked abnormalities in hemostatic mechanisms. This virus differs in this respect from Chikungunya virus to which it is immunologically similar and from other Thai hemorrhagic fever viruses.  相似文献   

16.
17.
以一株来自于白车根草(Trifolium repens L.)上的苜蓿花叶病毒分离物AMV-SY为材料,在电镜下观察测量经醋酸铀负染的196个提纯病毒粒子,按其长度分成等距离的5个组,用统计分析方法确定组间的差异。所得各组粒子的平均大小依次是组Ⅰ:(20.4 ±2.5) nm×(18.7±2.3) nm,组Ⅱ:(28.0 ±2.4) nm×(18.1±2.1) nm,组Ⅲ:(36.0 ±2.4) nm×(17.2±2.0) nm,组Ⅳ:(44.8 ±2.7) nm×(16.9±2.0) nm,组Ⅴ:(52.0 ±3.0) nm×(17.4±1.0) nm。它们分别相当于前人根据X-射线衍射或核磁共振所测定的Ta-t,Ta-b,Tb, M和B型病毒粒子。方差分析表明,5组病毒粒子间长度差异极显著,即组Ⅰ<组Ⅱ<组Ⅲ<组Ⅳ<组Ⅴ;病毒粒子宽度差异也极显著,但仅组Ⅰ粒子的宽度明显大于组Ⅳ 和组Ⅲ,说明在没有病毒RNA参与的情况下,单由不含病毒RNA的外壳蛋白亚基所构成的粒子其横向结构较为松散。对AMV统计分析的结果与前人根据对病毒粒子结晶中典型的粒子进行X射线衍射分析或计算机模拟所获得的结果基本吻合,但组Ⅴ粒子,即最长一组AMV病毒粒子的统计长度明显小于结晶中X-射线衍射分析所测得最长的B型粒子。  相似文献   

18.
整合猪瘟病毒囊膜蛋白的假型鼠白血病病毒感染性的研究   总被引:1,自引:0,他引:1  
通过反转录-聚合酶链式反应(RT-PCR)扩增了猪瘟病毒(CSFV)的E0、E2和E012基因并进行了克隆与鉴定。构建了真核表达载体pcDNA-E0、pcDNA-E2和pcDNA-E012,通过与鼠白血病病毒(MuLV)假型病毒构建体系的两种质粒pHIT60和pHIT111瞬时共转染人胚肾细胞(293T),48h后收集假型病毒上清液,将假型病毒上清液超速离心后用抗CSFV的多抗进行Western-blot检测。结果证明E012蛋白能够在假型病毒颗粒表面表达,说明E012能够整合到此病毒粒子表面;用其感染多种宿主细胞,48h后检测发现在猪肾细胞(SK6,PK15)和猪睾丸细胞(ST)上,标记基因LacZ能有效表达,证实构建的CSFV假型病毒具有感染性。  相似文献   

19.
20.
海洋表层透光区通过光合作用产生的有机物主要以颗粒有机物(POM)的形式输送至深海。异养微生物以其对于POM的分解作用机制不同而分为两类:颗粒附着的附生菌(particle-attached mode,PAM)和自由营生的自由菌(free-living mode mode,FLM),是介导海洋中颗粒有机碳(POC)和溶解有机碳(DOC)循环的主要参与者。然而,目前对PAM和FLM的微生物群落组成和生物地球化学功能的理解大多局限于固定深度原位海水的探讨,或者在实验室模拟中以某一固定压力直接富集微生物。本次研究采用马里亚纳海沟“挑战者深渊”50米深表层海水,并接种13C标记和非标记的POM,设置0.1、10、30和60 MPa四个压力梯度,以逐渐加压的方式模拟颗粒物沉降过程进行富集培养,探讨了在模拟海洋有机颗粒物下沉过程中两种不同形式微生物的演替和相互作用的动态演变。结合稳定同位素探针技术(DNA-SIP)和16S rRNA基因的高通量测序,结果表明19个活性OTUs被13C所标记,主要隶属于α-Proteobacteria以及γ-Proteobacteria。在不同压力梯度下,附生菌或自由菌中活性OTUs的类型和丰度有显著差异。此外,微生物网络结构(network)的相互作用在高压下呈正向为主,表明着深海中存在着激烈的物种竞争,微生物群落在高压下表现出明显的分离和模块化,具体表现为network拓扑特征系数的弹性和稳定性。模拟颗粒沉降高压培养结果重点揭示了在沉降过程中,静水压力对海洋中下降颗粒物降解相关的微生物的群落结构和功能的调控作用。  相似文献   

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