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1.
致泻性大肠杆菌中发现小肠结肠炎耶尔森菌毒力岛   总被引:1,自引:0,他引:1  
目的 研究肠产志贺样毒素且具侵袭力的大肠杆菌 (ESIEC)菌株是否含有耶尔森菌的HPI(毒力岛 )基因。方法 采用PCR扩增和Southern杂交的方法。结果 从 35 %的ESIEC菌的染色体上同时扩出irp1、irp2和fyuA 3个片段 ,片段大小分别与小肠结肠炎耶尔森菌WA菌株的相应片段一致 ,鼠疫耶尔森菌HPI上的 6对引物均未扩出目的片段。 6 5 %的ESIEC使用以上 9对引物未扩出目的片段。ESIEC菌的染色体EcoRI酶切产物电泳后与小肠结肠炎耶尔森菌WA菌株的fyuA探针杂交出大小一致的条带 ,与irp1和irp2探针杂交出不同的带型。结论 ESIEC菌含有小肠结肠炎耶尔森菌的HPI,且有变异现象。ESIEC和EAEC的关系还有待于进一步的研究  相似文献   

2.
PCR结合寡核苷酸探针杂交检测临床常见真菌的实验研究   总被引:8,自引:0,他引:8  
目的 建立PCR结合生物标记的寡核甘酸探针斑点杂交技术,鉴定临床常见的真菌。方法 首先用真菌通用引物扩增白念球菌、热带念球菌、假热带念球菌、近平滑念球菌、光滑念球菌、解脂念球菌、克鲁斯念球菌、季也蒙念球菌、黄曲 霉、烟曲霉的核糖体大亚单位基因的保守区序列,然后用生物素标记的种特异性寡核苷酸探针与扩增产物杂交,并将此方法用于临床标本和临床分离菌株的检测。结果 通用引物可以扩增上述11种临床常见真菌的DNA,扩增片段长度在260bp左右。9种特异性探针分别与11种真菌标准菌株的PCR扩增产物杂交,结果表明每种探针都具有高度特异性。斑点杂交法和Southerm杂交法检测敏感性相同,为100fg;琼脂糖凝胶电泳法检测敏感性为1pg。通过69例临床标本和31例临床分析菌株的检测,PCR-杂交法的结果和真菌培养法的结果基本一致。结论 PCR结合生物素标记的寡核苷酸探针杂交技术可将9种临床常见真菌鉴定到种,方法快速、敏感、特异。  相似文献   

3.
日本血吸虫卵壳蛋白基因的筛选及EST序列测定   总被引:2,自引:0,他引:2  
目的 通过对日本血吸虫(Sj)成虫cDNA库的核酸杂交筛选,分离出Sj卵壳蛋白相关基因的cDNA克隆,并进一步探讨该基因的结构与功能关系。方法 用地高辛标记的特异性寡核苷酸探针对Sj成虫cDNA库进行膜原位杂交筛进,挑选出阳性克隆,用通用引物进行PCR扩增,获得cDNA插入片段,采用PCR直接序列测定法,对其部分序列进行测定,而后将EST序列输入GENEBANK进行同源性检索和分析。结果 本实验从Sj cDNA库筛选到9个不同的阳性克隆,用通用引物扩增出9十分子量大小不同的单一条带,其中两个为已知序列,其余7个为新的EST序列。结论 用寡核苷酸标记探针对Sj库中进行校酸杂交筛选是寻找特定目的基因的有效方法。  相似文献   

4.
建立应用长臂光敏生物素核酸探针和光敏地高辛核酸探针杂交。检测真菌的方法,并比较二者检测临床常见医学真菌的敏感性。设计并合成医学真菌通用引物,用PCR扩增白色念珠菌标准株的核糖体RNA基因,用长臂光敏生物素或光敏地高辛标记其纯化的扩增产物制备成相应的核酸探针,然后用上述两种探针对标本中的PCR扩增产物进行Southern杂交,检测医学真菌。通过用白色念珠菌感染大鼠,建立念珠菌病的实验动物模型,验证血培养法、PCR法和PCR扩增结合Southern杂交,检测真菌的敏感性。结果表明,这两种核酸探针可分别与白色念珠菌、热带念珠菌、新型隐球菌、黄曲霉菌、烟曲霉菌等9种真菌杂交呈阳性结果:与临床常见的细菌、病毒和哺乳动物组织细胞DNA杂交结果为阴性。利用实验动物模型比较了血培养法、PCR法和PCR扩增结合长臂光敏生物素核酸探针Southern杂交法检测真菌血症的灵敏度,实验证明后者的敏感性最高。总之,应用长臂光敏生物素核酸探针和光敏地高辛核酸探针与标本PCR扩增物杂交,检测上述真菌既特异和敏感,又不需放射性同位素。光敏地高辛核酸探针检测医学真菌的灵敏度略高于长臂光敏生物素核酸探针。  相似文献   

5.
松辽平原达乌尔黄鼠鼠疫自然疫源地鼠疫菌基因分型   总被引:1,自引:0,他引:1  
为了研究松辽平原达乌尔黄鼠鼠疫自然疫源地鼠疫耶尔森菌(以下简称鼠疫菌)的基因组成,采用PCR技术对分离自该疫源地88株鼠疫菌进行了基因分型,其中黑龙江4株、吉林43株、辽宁4株、内蒙37株,鼠疫菌DNA均由青海省地方病预防控制所鼠疫菌专业实验室提供。引物设计和PCR扩增方法:在周冬生等鉴定的22个差异区段(DFR)中,有3个位于pMT1质粒中,19个位于染色体上。采用ArrayDesigner2.0软件针对每个DFR各设计1对引物,为了证实pMT1的存在,我们还特意针对pMT1质粒设计了1对引物,引物序列为5′AACACTA TCTCATTCCGCAGTAAAG3′。PCR…  相似文献   

6.
目的确定古典型鼠疫耶尔森菌的特有序列,为建立和完善该菌基因组分型系统提供可靠数据。方法通过抑制削减杂交技术发现差异片段并应用PCR验证。结果发现了5个在不同生物型鼠疫菌问存在差异的DNA片段,其中一个383bp的片段在来自天山山地灰旱獭、长尾黄鼠鼠疫自然疫源地的30株鼠疫菌全部阳性,而来自其它鼠疫自然疫源地的菌株全部阴性,5株假结核耶尔森菌中有2株(生物Ⅰ型和Ⅱ型)阳性。结论该383bp片段为天山山地灰旱獭、长尾黄鼠鼠疫自然疫源地的鼠疫菌所特有,此疫源地的菌株可能是我国较古老的鼠疫菌。  相似文献   

7.
致病性耶尔森氏菌PCR扩增多态性的研究   总被引:8,自引:0,他引:8  
目的为了解不同来源的鼠疫耶尔森氏菌和不同血清型的小肠结肠炎耶尔森氏菌及假结核耶尔森氏菌(PTB3)的遗传学差异。方法使用随机引物扩增多态DNA(RAPD)技术。结果鼠疫耶尔森氏菌和假结核耶尔森氏菌的扩增主带型相似,而与小肠结肠炎耶尔森氏菌的差异较大;不同来源的鼠疫耶尔森氏菌株RAPD图谱亦有细微差别。小肠结肠炎耶尔森氏菌不同血清型的菌株以及同一血清型不同来源株的RAPD亦有较大差异。这为耶尔森氏菌更进一步的分型提供了一种新方法。此外,还根据小肠结肠炎耶尔森氏菌肠毒素基因设计了一对引物,将7个血清型66株小肠结肠炎耶尔氏菌分成两组,一组的扩增为预期的289bp片段,另一组为约200bp的片段。结论实验表明,鼠疫菌和假结核菌可以通过RAPD和其它生物学技术相结合加以区分。使用RAPD技术可对同一血清型不同来源的小肠结肠炎耶尔森氏菌进行更进一步分型。上述方法可用于分子流行病学调查。  相似文献   

8.
微量酶联杂交法定量检测HBV基因 竞争PCR扩增产物   总被引:15,自引:1,他引:14  
目的 建立一种简便、敏感、精确的微反应板酶联杂交技术,以鉴定HBV基因的竞争PCR扩增产物。方法 设计了两种捕获探针,能分别与竞争PCR扩增产物中的野生片段和突变片段杂交。捕获探针通过3′-端修饰的氨基与微量DNA结合板孔表面的NOS基团化学结合而被“竖直”地包被在反应板上;将热变性后的产物加入两种捕获探针反应孔内,产物中带有生物素的野生或突变片段的一条单链与相应的捕获探针杂交;最后用链亲和素-碱性磷酸酶及底物检测杂交信号。结果 该方法检测PCR产物DNA的灵敏度为80ng/ml,大于琼脂糖凝胶电泳染色鉴定法。获得野生片段和突变片段杂交信号值后,可根据公式计算扩增前野生模板的初始量。结论 本方法操作简单、灵敏度高、结果数据化、特异性强,适用于竞争PCR产物分析。  相似文献   

9.
以往对cDNA克隆鉴定过程中,经斑点杂交筛选出的克隆数较多,在进一步的鉴定中不可避免地要进行质粒扩增、抽提、纯化酶解、片段分离等许多步骤。本文对这一步的鉴定采用了PCR技术,这样便可省去酶解及片段分离等繁琐步骤。且由于扩增片段纯净,故可直接用于Southern blot鉴定及DNA序列分析。 本文另一新的探索是利用PCR法标记探针,尤其是小片段DNA探针,其不同于常用的缺口平移和随机引物延伸标记。由于它在扩增过程中只有位于两个引物间的片段才能标上同位素,所以标记后的探针量大、比放射性强,加之PCR合成仪的出现,使此法更加高效、简便安全。  相似文献   

10.
作者介绍了一种分离染色体特定区带cDNA片段的方法——利用亲和捕获法筛选杂交体(SHAC)。 在倒置显微镜下切割持定的染色体或染色体区带,然后用DOP-PCR进行两轮扩增,PCR产物用生物素标记后进行原位杂交检则其特异性;以特定组织的mRNA为模板构建cDNA文库,在cDNA的两端都加上一个连接体接头。生物素标记的PCR产物用Cot-1基因组DNA封闭重复顺序后与变性的cDNA文库在液相中杂交,杂交后用带有链霉亲和素的磁珠捕获带生物素的杂交体,然后用碱变性法释放所捕获的cDNA并进行PCR扩增。为了检测所  相似文献   

11.
Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc2 (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.  相似文献   

12.
Renal dysplasia and asplenia in two sibs   总被引:2,自引:0,他引:2  
A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.  相似文献   

13.
About 1900, modern food selection and processing caused widespread epidemics of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a panhypovitaminosis B, i.e., a mixture of substrate beriberi and substrate pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse endemic disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for primates. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.  相似文献   

14.
15.
Newton H 《Medical history》2011,55(2):153-182
Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.  相似文献   

16.
Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.  相似文献   

17.
The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.  相似文献   

18.
HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.  相似文献   

19.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.  相似文献   

20.
Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.  相似文献   

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