宁夏鼠疫菌质粒生物学特征研究

目的 研究宁夏126株鼠疫菌的质粒、毒力决定因子与毒力的关系，预测动物鼠疫的流行。方法 质粒凝胶电泳、毒力因子测定和半数致死量(LD50)试验。结果 被试菌株多数含有6，13，45，65MD质粒，具有4种毒力因子；在流行末期分离的菌株毒力较弱。结论 质粒分析可用于鼠疫菌的鉴别诊断。     

鼠疫菌质粒在鼠疫防治研究中的应用

质粒是独立于寄主细菌染色体复制的双股链环状DNA分子。近年来证明,许多细菌特性是由质粒携带的基因控制。通过对鼠疫菌质粒的研究,给鼠疫菌的毒力,致病力及其毒力因子等理论提供了科学的依据,现将有关鼠疫菌质粒的研究及其利用质粒或质粒的某个基因片段用做鼠疫的防治和科研诸方面的内容整理如下。1 鼠疫菌携带的质粒及分子量 鼠疫菌携带的质粒种类报道的较多,作者大致     

青海鼠疫菌株的毒力因子及某些相关因素的研究

对青海692株鼠疫菌的毒力因子研究结果表明,FI 和 PstI 全部为阳性;Pgm 和 VW 性质不太稳定,其阴性率分别为7.4%和2.6%。由于毒力因子是由质粒介导的,因此对某些毒力因子和质粒的关系进行了观察,发现在19株 VW~-菌株中仅3株失去45Md 质粒,多数菌株质粒无变化。Pgm~-菌株多分离自蚤类(斧形盖蚤和谢氏山蚤),由于这类菌株不易形成菌栓,它们难以引起动物间鼠疫流行。对两种毒力因子同时发生变异的菌株推测其毒力将会减弱。     

吉林西北部草原鼠疫菌质粒及酶切图谱的研究

为探讨吉林西北部草原鼠疫菌分子生物学性状,本研究测试了该地区３０株鼠疫菌携带的质粒种类和质粒ＤＮＡ酶切图谱。结果显示该地区鼠疫菌携带３种规范的质粒,即６５Ｍａｌ、４５Ｍｄａｌ和６Ｍｄａｌ质粒,质粒ＤＮＡ ＥｃｏＲⅠ酶切图谱可切成１６个片段。     

青海田鼠型鼠疫耶尔森氏菌生物学性状的研究

目的：通过试验菌株与对照菌株相比较，观察其生物学性状，确定试验菌株的生态型。方法：选择生物化学试验、毒力决定因子、营养型、毒力、质粒及外膜蛋白等项目。结果：试验菌株与对照菌株生物学性状有较大差异，生化性状为鼠李糖＋、甘油＋、脱氨－、麦芽糖＋、阿胶糖－、密二糖＋，毒力因子是鼠疫菌荚膜抗原（FraI^ )、毒力抗原（Vwa^ )、鼠疫菌素I（PstI^ )、色素沉着因子（Pgm^ ),营养型为精氨酸、亮氨酸依赖型（Arg^-、Leu^-),质粒为6、45、65Mdal质粒等。结论：确定了我国一个新的鼠疫菌生态型－青藏高原青海田鼠型鼠疫菌。     

广西鼠疫菌生物学性状的研究

目的 研究广西鼠疫菌生化特性，确定该地区鼠疫疫源地的性质。方法 包括糖醇酵解试验、毒力因子检测、脱氮反应、营养需求等，采用Kado温和法提取质粒。结果 广西鼠疫菌对麦芽糖、阿胶糖酵解，而对鼠李糖、甘油不酵解。毒力因子(pgm)6株阳性，5株弱阳性、4株阴性。31株鼠疫菌经质粒图谱分析，其中2株菌缺失65MD，1株菌携带111MD大质粒，其余均含有4,6、45和65MD质粒。结论 按中国鼠疫菌生态分型标准，被试菌株属滇西闽居民区型。     

我国小肠结肠炎耶氏菌毒力株的特征

本文对我国各地分离的小肠结肠炎耶氏菌的毒力特征进行测定,所有毒力株除个别外,均有VW抗原、Vi抗原和毒力因子,它们的检测结果一致。有毒株还有一条40～50MDa的质粒带,即所谓毒力质粒,但有此毒力质粒的菌株并非都是有毒株,视其有否特异性外膜蛋白(约200KDa)而定。自凝性也是检测耶氏菌毒力的一种方法,但其敏感性与特异性均不及VW抗原测定。因此测定菌株毒力,以VW抗原、Vi抗原和毒力因子测定最特异而敏感,特别后两种方法简单、易行、可靠,可在基层单位推广使用。     

cag致病岛与幽门螺杆菌致病作用的关系

幽门螺杆菌（Ｈ．Ｐｙｌｏｒｉ）诱导疾病发生的分子机制目前尚不清楚，针对Ｈ． ｐｙｌｏｒｉ致病相关因素的研究仍在继续深人。１９９６年Ｃｅｎｓｉｎｉ等［１］在ｃａｇＡ阳性Ｈ ｐｙｌｏｒｉ菌株中发现的新的ＤＮＡ片段──ｃａａ致病岛，被认为是Ｈ． ｐｙｌｏｒｉ中的又一致病相关因素。本文就ｃａｇ致病岛与Ｈ．ｐｙｌｏｒｉ相关致病因子的关系作一简要综述。 一、致病岛的概念 致病菌中编码毒素、粘附因子、侵袭因子或其他毒力因子的致病基因存在于细菌染色体特定区域中，并出现于诸如转座子、质粒、噬菌体等可转染的遗传学元件中…     

鼠人肝再生增强因子的cDNA克隆及序列分析

目的克隆大鼠及人肝再生增强因子的ｃＤＮＡ．方法按文献报道大鼠及人肝再生增强因子核苷酸序列设计合成引物．利用ｍＲＮＡ抽提试剂盒分别从乳鼠及人胎肝组织中提取ｍＲＮＡ，再逆转录聚合酶链反应扩增出需要的ｃＤＮＡ片段，经克隆入ｐＧＥＭＴ质粒后以Ｔ７ＤＮＡ聚合酶序列分析试剂盒测定ｃＤＮＡ的序列．结果经ＲＴＰＣＲ反应顺利扩增到４７０ｂｐ的鼠肝再生增加因子ｃＤＮＡ及３８４ｂｐ的人肝再生增强因子．结论所得到的ｃＤＮＡ序列与文献报道一致     

耶氏菌属毒力株共同血清学特性

<正> 取氏菌属细菌(鼠疫耶氏菌、假结核耶氏菌和小肠结肠炎耶氏菌)对人和动物都能引起侵袭性疾病,他们的致病性与一分子量40～48Mdal的毒力质粒有关。该质粒编码VW抗原,自凝因子和特异外膜蛋白。我们对该属细菌毒力株的共同血清学特性进行了研究,发现采用小肠结肠炎耶氏菌酶免疫斑点试验,可以把这3种细菌的毒力株和无毒力株区别开来。     

Alcohol misuse and juvenile offending in adolescence

The associations between alcohol misuse and juvenile offending during the period from 15 to 16 years of age were studied in a birth cohort of New Zealand adolescents. This analysis showed that young people who misused alcohol had significantly (p < 0.001) higher rates of both violent and property offences. These associations were similar for males and females. Further analysis suggested that a substantial component of the association between alcohol misuse and juvenile offending arose from shared risk factors that were common to both outcomes. These risk factors included measures of family social background, family and parental characteristics, individual characteristics and adolescent peer affiliations. After adjustment for antecedent risk factors there was no significant association between alcohol misuse and odds of property offences. However, young people who abused alcohol had odds of violent offending that were 3.2 times (p < 0.001) the odds of those offences for young people who did not misuse alcohol. It is concluded: (a) that a large component of the association between alcohol misuse and juvenile offending arises because of the effects of shared risk factors that are associated with both outcomes; (b) none the less, the unexplained association between alcohol misuse and violent offending may suggest the presence of a direct cause and effect association in which adolescent alcohol misuse is associated with increased risks of violent offending.     

致肾盂肾炎大肠杆菌粘附基因群DNA多态性的研究

目的　研究临床分离的致肾盂肾炎大肠杆菌粘附基因群DNA的多态性。方法　以血凝试验 (MRHA)为基础 ,分别用编码P菌毛主体结构和尖端粘附素的基因探针 ,采用DNA杂交方法对临床分离的 95株尿源性大肠杆菌的粘附基因群进行分析。结果MRHA +++～ ++++占 37 9% (36株 ) ,++占 32 6 % (31株 ) ,MRHA阴性占 2 9 5 % (2 8株 )。菌落原位杂交和DNA斑点杂交试验在MRHA +++～ ++++,++和阴性菌株中两个探针均为阳性的分别为 91 7%、9 7%和 2 1 4% ;在MRHA ++和阴性菌株中单一探针阳性的分别为 6 4 5 %和 35 7%。同时 ,选 10株MRHA ++++大肠杆菌提取染色体DNA ,经EcoRⅠ酶切后Southern杂交进行限制性片段长度多态性分析 ,同源性DNA片段大小不一 ,杂交信号的强弱程度也不同。结论　提示致肾盂肾炎大肠杆菌pap粘附基因群的多样性。     

Variable hematopoietic graft rejection and graft-versus-host disease in MHC-matched strains of mice

MHC typing for human hematopoietic cell transplantation (HCT) from unrelated donors is currently performed by using a combination of serologic and molecular techniques. It has been determined that allelic differences in human MHC molecules, revealed by nucleotide sequencing but not by serologic typing, substantially influence graft rejection and graft-versus-host disease, two serious complications of clinical HCT. We studied transplantation of purified hematopoietic stem cells in a series of mouse strains that were matched at the MHC but had different background genes, and we observed striking differences in engraftment resistance and graft-versus-host disease severity, both factors depending on the donor-recipient strain combination. The individual mouse lines studied here were established nearly a century ago, and their MHC types were determined exclusively by serologic techniques. We considered the possibility that serologically silent MHC polymorphisms could account for our observations and, therefore, we performed DNA sequencing of the class I and II MHC alleles of our mouse strains. At each locus, exact homology was found between serologically MHC-matched strains. Our results likely extend to all serologically MHC-matched mouse strains used in modern research and highlight the profound and variable influence that non-MHC genetic determinants can have in dictating outcome after HCT.     

间日疟原虫环子孢子蛋白基因型的鉴别研究

[目的 ]建立间日疟原虫环子孢子蛋白 (CSP)基因分型法用于地理株的鉴定。[方法 ]Chelex 10 0离子交换法提取滤纸血样中的微量DNA ;套式PCR和等位特异PCR技术、琼脂糖电泳分析法、斑点印迹和Southern印迹 探针杂交技术分别用于判别性片段的扩增、分析和鉴定。[结果 ]用本文描述的套式 等位 特异PCR分型法 ,从一小片滤纸血样提取的微量DNA中 ,扩增出不同长度范围的 3种判别性片段 :6 5 0～ 770bp(间日疟种特异 ) ,15 0～2 30bp(温带族特异 ) ,5 88～ 6 15bp(PV 2型特异 )。用本法检测参考虫株出现的带型和长度与设计的靶序列完全吻合。检测 5 9份国内感染血样 ,42份鉴定为温带族虫株 ,15份为热带族虫株 ,2份为PV 2型虫株。 4份境外感染血样中 ,2个巴基斯坦分离株均为温带族 ,缅甸和老挝各 1株均为热带族虫株。 [结论 ]①本法能同时区分PV 1型 ,PV 2型以及温带族与热带族虫株 ,且较现有 (PCR 探针杂交 )法更为简便、快捷 ;②现场血样初步检测结果显示 :我国存在PV 1型 (温带族与热带族 )虫株和PV 2型虫株 ,也可能存在温带族东南亚组虫株。     

Virulence and pathogenicity of Helicobacter pylori

Bacterial and host response factors play significant roles in the pathogenicity of H. pylori-related disease manifestations. The complete DNA sequences for two H. pylori strain genomes have been published. The differences in the sequences between these two unrelated strains may enable clinicians to identify rapidly other conserved and potentially virulent genes and products. Whether these two DNA sequences are sufficient representation of the H. pylori genetic heterogeneity is unknown. The host immune response and the cascade of events that occurs with H. pylori infection are being clarified rapidly. Understanding the role of this gastric bacterium in apoptosis and cellular proliferation would enable clinicians to understand its relationship to ulcerogenesis and gastric malignancy. Piecing together many observations related to H. pylori would result in understanding the interaction of H. pylori factors and host responses that lead to the variety of disease manifestations associated with this chronic infection. The development of animal models with H. pylori and other Helicobacter species has set the stage in which in vitro observations can be tested in the in vivo model.     

人源弓形虫分离株的生物学鉴定及群体DNA含量分析

通过对不同分离株弓形虫抗原的分析 ,探讨弓形虫虫株间的差异性。取弓形虫 CAg阳性血液标本进行小鼠接种 ,对分离株进行生物学特性鉴定 ;采用流式细胞仪 ( FCM)对分离株弓形虫速殖子进行群体 DNA含量分析。结果在 5份 CAg阳性血液样本中分离到 4株弓形虫 ,两者符合率达 80 % ;经生物学鉴定结果显示 ,4个分离株的形态大小、毒力及抗原性均与 RH株弓形虫相似。上述 5株弓形虫速殖子 DNA含量分析均呈明显规律性 ,即均有 2个分布峰 ,但各虫株间的 2个分布峰中所占速殖子数存在显著性差异 ( P<0 .0 1)。表明检测弓形虫 CAg可作为弓形虫早期、急性期感染的确诊指标 ;采用流式细胞术进行 DNA群体分析 ,似可反映弓形虫虫株间的差异     

弓形虫种株DNA多态性研究

目的分析比较3株弓形虫基因组DNA的多态性。方法应用随机扩增的多态性DNA（andomamplifiedPolymorphicDNA－RAPD）技术对弓形虫RH株、BH株、PP株基因组DNA扩增产物进行琼脂糖电泳。结果单一及复合引物均能扩增产生多态性的DNA指纹图谱。3株弓形虫基因组DNA扩增产物的带型和强度均有不同。根据Net’s相似系数对3株弓形虫基因组DNA遗传相似性进行定量分析,用不同的引物扩增,虫株间表现出不同的相似性。结论表明3株弓形虫基因组DNA经RAPD反应产生的多态性能够应用于弓形虫种、株的鉴定和分类。     

中国炭疽芽胞杆菌中11个串联重复序列位点的特征和分布

目的检测炭疽芽胞杆菌中可变数量串联重复序列(VNTR)的变化,分析我国菌株中VNTR的特征和分布规律。方法 PCR扩增,琼脂糖电泳和毛细管电泳,测序验证,BLAST比对等。结果 11个VNTR位点中有4个在所有菌株中没有差别,另外7个位点只在个别菌株中检测到差别,有差别的菌株多分布在新疆;11个VNTR位点均位于基因编码区内,编码对细菌生存重要的蛋白和一些功能不明蛋白。结论结果提示新疆的菌株类型较复杂;本研究中的VNTR位点比较保守,可能不能用于区别不同的炭疽芽胞杆菌,但对于了解炭疽芽胞杆菌的基因组特征以及鉴定炭疽芽胞杆菌具有一定的作用。     

Violence and violent feelings: what causes them among family caregivers?

We present a conceptual framework for understanding two distinct but related phenomena: violent feelings (i.e., the fear of becoming violent) and violent behaviors by family caregivers toward relatives with dementia. Based on both the literature on family caregiving and on family violence, four factors are hypothesized to explain these two dimensions of violence: caregiving demands, interactional stressors, caregiver characteristics, and caregiving context. Analyses of quantitative and qualitative data on 236 family caregivers to dementia victims revealed several characteristics that were predictive of violent feelings on the part of caregivers, including physical aggression by the care recipient, disruptive behaviors, and a shared living situation. Structural relationship and caregiver's age were found to be related to actual violence; spouses were more likely to engage in violence than other relatives, as were older individuals. In addition, violence by the care recipient was positively related to caregiver violence.     

我国不同地区周期型马来丝虫基因组DNA多态性研究

目的分析我国不同地区马来丝虫基因组的多态性.方法用随机扩增多态DNA(RAPD)技术对我国6省区周期型马来丝虫基因组DNA多态性进行了检测.结果经20个引物扩增得到51个多态片段,6株丝虫共有片段2个,特有片段9个.结论片段共享度及聚类分析所得的6株丝虫的亲缘关系与同工酶、电镜及氨基酸研究的结果基本一致,即地理位置相距近则亲缘关系密切.