磁纳米散射探针暗场超灵敏检测具核梭杆菌

【背景】具核梭杆菌（Fusobacterium nucleatum）作为机会致病菌,能够引起许多感染性疾病,已被证实是促直肠癌发展的潜在重要危险因素,临床检测中亟需一种快速简单检测F. nucleatum的方法。【目的】通过建立一种磁纳米探针结合暗场显微镜直接观察计数的方法,可方便快速地检测样本中具核梭杆菌的数量。【方法】在磁纳米颗粒（magnetic nanoparticle,MNP）表面修饰制备的抗F. nucleatum抗体,构建一种特异性结合F. nucleatum的MNP探针。此外,比较MNP探针-暗场显微计数法与实时荧光定量PCR （qPCR）方法检测F. nucleatum的灵敏度。【结果】该方法的检测限可低至3.42×10¹ copies/μL,比qPCR的灵敏度高5倍左右。在实际样本的检测中,该方法与qPCR方法所检测F.nucleatum数量保持一致。【结论】本研究建立的方法用于检测F.nucleatum,操作简单、检测快速（约30 min）、灵敏且成本低,有应用于临床样本检测的前景。     

水霉菌环介导等温扩增检测方法的建立

【目的】建立一种快速简单检测水霉病病原菌的方法。【方法】针对水霉菌ITS区基因序列设计4条特异性引物,包括两条外引物和两条内引物,优化反应条件,观察检测结果。对该方法的特异性和敏感性进行研究。【结果】建立了环介导等温扩增技术检测水霉菌的方法,确定了其最适反应条件。该方法能够检测到浓度低至103个/mL的水霉菌孢子,其灵敏度是普通PCR方法的100倍。【结论】建立的检测水霉菌的LAMP技术,具有操作简便快速等特点,可用做特异性水霉及其孢子的快速鉴定。     

A组轮状病毒可视化RT-LAMP方法的建立

【目的】建立一种利用颜色判定的快速、简单、灵敏度高的检测方法,即可视化的逆转录环介导等温扩增(RT-LAMP)方法,并应用于人A组轮状病毒的基因检测。【方法】针对A组轮状病毒VP6基因的6个保守区域设计4条特异性引物,在64 °C恒温条件下进行核酸扩增反应1 h,在扩增前加入染料钙黄绿素(Calcein)作为反应指示剂,以钙黄绿素的颜色变化作为结果判定标准。评价该方法的特异性和灵敏度,并同时利用RT-LAMP和RT-PCR两种方法对90份临床腹泻样本中的病毒核酸进行检测。【结果】RT-LAMP方法特异性较高,灵敏度可以达到103 copies/μL RNA分子水平,比RT-PCR高出100倍。对临床标本的检出率与RT-PCR方法相当。【结论】建立的RT-LAMP法灵敏度较高,特异性强,节省时间,结果可视化,具有野外检测和现场快速检测的潜力。     

可视化抗体阵列快速联合检测大肠杆菌O157:H7和鼠伤寒沙门氏菌

【目的】建立一种同时快速检测大肠杆菌O157:H7(E.coli O157:H7)和鼠伤寒沙门氏菌(Salmonella typhimurium)的可视化抗体阵列技术。【方法】将免疫学技术与蛋白芯片技术相结合,基于双抗体夹心法检测原理利用蛋白质芯片技术的高通量,结合可视化结果判定技术,用一份样品,同步检测大肠杆菌O157:H7和鼠伤寒沙门氏菌两种病原。【结果】检测结果肉眼可见,检测周期短至90 min,纯菌液检测灵敏度达105 CFU/mL,模拟带菌检测灵敏度为106 CFU/mL,与常规的ELISA灵敏度等同且具有良好的特异性和重复性。【结论】该可视化抗体阵列检测结果肉眼可见,检测通量高,无需大型设备,操作简便,检测成本低廉,同时为快速检测致病菌提供一种新途径。     

非洲猪瘟病毒微滴数字PCR (ddPCR)方法的建立及应用

【目的】非洲猪瘟病毒(African swine fever virus,ASFV)能导致猪群高死亡率,从而造成严重的经济损失。因此,建立严密、高效的防控系统,包括灵敏、准确的诊断方法以及高效的预报预警机制等,以避免ASF传入我国。本文旨在建立一种新型而高灵敏度的ASFV微滴数字PCR(Droplet digital PCR,dd PCR)检测方法。【方法】针对ASFV K205R基因设计一对特异性引物和Taq Man探针,通过反应条件优化,建立了ASFV实时荧光定量PCR(q PCR)和dd PCR检测方法;并对两种方法的线性关系、灵敏性、特异性和重复性进行了评估,利用建立的ASFV检测方法对163份国内和进境的组织样本及血清样本进行检测,血清样本经商品化ASFV ELISA试剂盒复检,评估不同方法检测结果的符合率。【结果】建立的ASFV q PCR和dd PCR检测方法线性关系较好(R2≥0.998),dd PCR的最低检测限度可达到0.36拷贝,在20μL反应体系中约为10拷贝/反应,检测灵敏度是q PCR的10倍。ASFV dd PCR检测方法具有很高的特异性和重复性,不与其他猪常见病毒发生交叉反应。【结论】该方法灵敏度高、特异性强,可作为一种有效的分子生物学方法来诊断ASFV,为防止该病传入我国以及ASFV的实时监测提供新的技术储备,同时促进dd PCR技术在我国的发展和应用。     

唐菖蒲伯克霍尔德氏菌椰毒假单胞菌酵米面亚种环介导等温扩增荧光方法的建立

【目的】建立一个基于环介导等温扩增与荧光探针结合的唐菖蒲伯克霍尔德氏菌椰毒假单胞菌酵米面亚种(Burkholderia gladioli pv. cocovenenans)特异性检测方法。【方法】通过多重序列比对分析,选择B. gladioli pv. cocovenenans共有的bonA为靶位点,设计环介导等温扩增的特异性引物和荧光探针,通过19株B. gladioli和3株非目标菌株,验证该方法的特异性。将该方法的检测特异性与现有的基于实时荧光定量PCR鉴定B. gladioli pv. cocovenenans的方法进行比较,并对建立的方法进行灵敏度探究。【结果】建立的环介导等温扩增荧光鉴定方法对B. gladioli pv.cocovenenans具有特异性,能在30 min内得出结果,且该方法能进行可视化直接观测。该方法的基因组DNA最低检测限度为1.98pg/μL,检测灵敏度为2.7×10²CFU/mL。另外,该方法能应用到食品样品中B. gladioli pv. cocovenenans的检测。【结论】本研究建立了一个快速、可视化、特异性强的检测方...     

基于聚合酶螺旋反应技术快速检测铜绿假单胞菌

【背景】铜绿假单胞菌是一种重要的水源和食源性致病菌,可引起急性肠道炎、脑膜炎、败血症和皮肤炎症等疾病。加强铜绿假单胞菌的快速检测,对保障食品安全具有重要的意义。【目的】建立聚合酶螺旋反应(Polymerasespiralreaction,PSR)方法快速检测铜绿假单胞菌。【方法】针对铜绿假单胞菌外毒素A调控基因——ETA基因(toxA)设计引物,通过引入加速引物、优化反应条件和筛选颜色指示剂,建立快速检测铜绿假单胞菌的PSR方法,并研究方法的特异性、敏感性和可靠性。【结果】建立的方法在等温65°C条件下,40 min内可完成PSR反应,且可通过钙黄绿素和羟基萘酚蓝直接判读结果。方法特异性强、灵敏度高,最低检出限分别为20 CFU/mL细菌和1.011 5 pg/μL基因组DNA。可视化PSR方法检测包装饮用水来源的分离菌株与传统生化方法检测结果一致。【结论】研究建立的可视化PSR方法为铜绿假单胞菌DNA快速检测提供了一种可行的有效手段。     

环介导等温扩增技术在食品中痢疾志贺氏菌快速检测

【目的】探讨、优化基于环介导等温扩增技术(LAMP)快速检测常规食品中感染性痢疾志贺氏菌的方法。【方法】在NCBI数据库中搜索获取志贺氏菌的特异性基因高度保守区,设计3对LAMP反应引物,建立、优化该LAMP可视化检测方法,并评价其特异性、灵敏度,同时与PCR检测方法和传统检测方法对比,进行结果统计分析。【结果】5株志贺氏菌标准菌株样品均检测为阳性,11株非志贺氏菌标准菌株样品均检测为阴性,无交叉反应。最低检验限为1.6×101 CFU/反应(或1.6×101 CFU/m L),且经比较,LAMP检测灵敏度比PCR检测高出1个数量级。通过对161份实际样品和人工污染样品进行检测,LAMP检测与传统方法检测结果具有较高的一致性。【结论】LAMP具有检测过程快速简便、检测结果稳定、可靠的特点,适用于对常规食品中感染性痢疾志贺氏菌的高效、快速检测需求。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.