首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
用埃立克体属特异性套式PCR和DNA序列测定从西藏微小牛蜱检出边缘无形体和埃立克体;用半套式PCR扩得该埃立克体的16S rRNA基因,并测定了它的序列;将该埃立克体的16S rRNA基因序列与其它埃立克体的16S rRNA基因序列进行对比分析,结果证明它的16S rRNA基因与埃立克体属的犬埃立克体群16S rRNA基因相似水平最高(97%~98%);用16S rRNA基因序列做系统发育分析,结果显示该采自西藏的微小牛蜱的埃立克体可能是与查菲埃立克体密切相关的一种新埃立克体.  相似文献   

2.
野外采集标本中人埃立克体16S rRNA基因扩增方法及应用   总被引:3,自引:0,他引:3  
本文应用特异引物,通过多对半巢式PCR从采自内蒙古大兴安岭的蜱标本中扩增出人粒细胞埃立克体和查菲埃立克体的16SrRNA全基因,一方面提供了这2种埃立克体存在于中国的证据,另一方面为今后进行埃立克体病的病原、媒介和宿主的调查研究提供了一个可行的方法.并从一只大林姬鼠的脏器中检测到EC16SrRNA基因片段.  相似文献   

3.
查菲埃立克体 (Ehrlichiachaffeensis)是人单核细胞埃立克体病 (humanmonon cyticehrlichiosis,HME)的病原体 ,已证实我国存在该病原。血清学分析是目前诊断HME及其流行病学调查的主要方法。但由于该病原体为严格胞内寄生菌 ,难以通过细胞培养制备大量抗原去满足临床HME的血清学诊断和流行病学调查的需要。P12 0 (相对分子质量为 12 0×10 3蛋白 )为查菲埃立克体主要表面抗原 ,具有种特异性。该蛋白基因包含了多个连续的 2 40bp重复单位 ,占全基因的 6 0 % ,并均为B淋巴细胞识…  相似文献   

4.
目的建立一种快速有效检测环境中q变形菌纲磁螺菌属细菌的方法。方法本研究以α变形菌纲磁螺菌属保守且特异的16SrRNA片段为靶序列,化学合成基因序列,制备重组质粒作为磁螺菌属检测的标准品;用实时荧光定量聚合酶链反应(FQ—PCR)技术,针对目的片段基因设计特异性引物和TaqMan荧光探针,进行实时荧光定量PCR检测,运用统计学方法评价该方法的特异性、敏感性及重复性。结果本实验成功构建了质粒PUC19-QC,引物、探针特异性良好,标准曲线在5.10×10^1~5.10×10^7拷贝数之间具有较好的线性关系,相关系数R2=0.999。该法最低可检测到5.10x10个DNA拷贝数,灵敏度明显高于普通PCR;重复性试验表明.荧光定量PCR检测结果Ct值波动范围较小,α值的标准差均小于0.23,表明该法重复性好,可靠性高。析因方差分析表明不同稀释度之间的ct值差异有统计学意义(F=3125.305,P〈0.001),三个批次的再现性良好,差异无统计学意义(F=0.057,P=0.945),而浓度分组与时间之间也无交叉效应(F=0.533,P=0.873)。结论本实验所建立的TaqMan探针实时荧光定量PCR检测技术,能够快速有效地检测仅变形菌纲磁螺菌属细菌,且检测结果稳定,受外界条件如时间、气温等影响小。  相似文献   

5.
PCR检测蜱中查菲埃立克体DNA及其序列分析   总被引:20,自引:1,他引:19  
应用从查菲埃立克体16SrRNA基因序列高变区构建的特异引物,进行PCR,检测蜱标本中病原体DNA。结果从云南采集的龟形花蜱、从福建采集的越原血蜱和卵形硬蜱扩增出389bp的特异DNA片段。收集龟形花蜱和越原血蜱的特异PCR产物,通过与T载体连接,进行克隆和序列测定。其DNA序列与美国查菲埃立克体分离株对应位置相差一个核苷酸,与其它种埃立克体的同源性为80.7%~96.1%。这是首次在我国发现埃立克体存在的病原线索,表明在我国南方可能存在人单核细胞埃立克体感染的自然疫源地  相似文献   

6.
目的 采用逆转录结合实时荧光定量PCR技术,建立一种快速、准确、特异甄别单核细胞增生李斯特菌(Listeria monocytogenes,简称单增李氏菌)死活状态的定量方法.方法 根据单增李氏菌hlyA基因序列设计引物和探针;对实时荧光PCR反应体系进行优化后,提取菌体mRNA,通过随机引物进行逆转录反应;产生的cDNA通过实时荧光定量PCR进行鉴定.进一步评价逆转录结合实时荧光定量PCR方法的特异性、灵敏度、重复性后,对20份模拟双盲样本进行检测.结果 本实验所建立的逆转录结合实时荧光定量PCR方法可准确、特异地检测单增李氏菌,其他菌株和失活的单增李氏菌均无阳性结果出现;该方法检测纯菌和模拟样本的灵敏度分别可达到10 CFU/ml和1000CFU/ml;定量检测的批间和批内的变异系数均小于5%;对20份模拟样本进行检测,其中10份含有活性单增李氏菌样本的检测结果均为阳性,其他含有失活单增李氏菌的5份样本和其他致病菌的5份样本检测结果为阴性.结论 本文建立的检测活性单增李氏菌实时荧光定量PCR方法快速、准确,结果可靠,实用性强,可进行定量分析,为食品安全监测和现场流行病学调查提供较好的分析手段和完整的数据.  相似文献   

7.
目的采用TaqMan探针建立检测沙眼衣原体的实时荧光定量PCR(real-time PCR)方法。方法根据沙眼衣原体外膜蛋白A的基因(ompA)序列设计引物和探针,以克隆的ompA部分基因片段作DNA模板,建立实时荧光定量检测方法。结果建立的荧光定量PCR检测方法的最低检出限为5 copies/反应,检测线性范围100~107线性关系良好(r2=0.997),比巢式PCR敏感100倍;且与鹦鹉热衣原体、淋球菌、解脲脲原体、大肠杆菌等病原菌DNA以及人基因组DNA均无交叉反应,表明该方法具有良好的特异性。以巢式PCR作参比,建立的荧光定量PCR法检测沙眼衣原体的阳性符合率为100.00%,阴性符合率为95.09%,总符合率为96.81%。结论建立的检测沙眼衣原体实时荧光定量PCR具有特异性强和敏感性高的特点,可快速检测样本中微量沙眼衣原体DNA,适用于对沙眼衣原体进行大规模筛选。  相似文献   

8.
目的 采用顺序特异引物聚合酶链反应 (PCR -SSP)建立人类白细胞抗原DR位点的DNA分型方法 .方法 合成 2 9个特异性引物和 1对阳性对照引物 ,组成 2 0个PCR反应用于DR位点 ,建立一步法PCR -SSP .结果 所有样本PCR -SSP基因分型获得成功 ,分型结果经标准DNA ,限制性核酸内切酶分析证实符合 ,特异性和重复性 10 0 % .结论 PCR -SSP检测HLA -DR的方法具有快速、准确、特异性高等优点 ,适合临床应用 .  相似文献   

9.
目的 建立人类疱疹病毒6型(HHV-6)荧光定量PCR检测方法,并检测临床样本.方法 根据文献合成HHV-6 U65-66基因片段的特异性引物和TaqMan探针,构建质粒制备标准品,评估该方法的特异性、灵敏度和重复性;并用该方法检测93份临床诊断为病毒性脑炎的脑脊液标本.结果 本实验检测HHV-6的灵敏度为3×10(0)拷贝/μl;标准曲线间线性关系(R2)为0.999,扩增效率为97.9%;同一样本重复检测3次,组内Ct值的变异系数最大为0.61%,组间为3.13%;特异性检测中只有HHV-6阳性标本出现扩增曲线.93份临床标本中检出HHV-6阳性2例,检出率为2.15%.结论 本实验所建立的荧光定量PCR检测HHV-6的方法特异强、灵敏高、重复性好,具有应用于临床检测的潜在价值.  相似文献   

10.
多重实时荧光定量PCR检测肠出血性大肠杆菌O157:H7   总被引:1,自引:0,他引:1  
目的 利用多重荧光定量PCR技术,建立一种快速、准确、特异检测肠出血性大肠杆菌O157:H7的定量方法.方法 选取肠出血性大肠杆菌O157:H7编码脂多糖基因(rfbE)和编码鞭毛抗原基因(fliC)作为检测的靶基因,设计引物和TaqMan-MGB探针,探针的5'端分别用FAM和HEX进行荧光标记,3'端标记MGB.优化PCR扩增体系,对多重实时荧光定量PCR方法的特异性、灵敏度、重复性评价,同时进行一定数量临床样本鉴定,与常规方法进行比较.结果 本研究所建立的多重实时荧光定量PCR方法可准确、特异地检测和鉴定肠出血性大肠杆菌O157:H7,能够有效甄别肠出血性大肠杆菌O157:H7与非H7菌株,其他菌株均无阳性结果;该方法的灵敏度可达到10 CFU/ml;定量检测的批间和批内变异系数均小于5%;对66例临床样本进行评价,结果显示15例肠出血性大肠杆菌O157:H7阳性,2例为肠出血性大肠杆菌O157:非H7阳性,其中16例与常规培养法结果符合,符合率达到98.49%.结论 本研究建立的检测肠出血性大肠杆菌O157:H7多重实时荧光定量PCR方法快速,结果准确、可靠,操作简便,为肠出血性大肠杆菌O157:H7的临床诊断、现场流行病学调查和食品安全监测提供了新的鉴定方法.  相似文献   

11.
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   

12.
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   

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.
There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.  相似文献   

15.
16.
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   

17.
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   

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.
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   

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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号