免疫印迹法在实验大鼠汉坦病毒监测中的应用及与间接免疫荧光法之比较

用汉坦病毒汉滩株（７６－１１８）重组核蛋白作为免疫印迹法（ＷｅｓｔｅｒｎＢｌｏｔ以下简称ＷＢ）的诊断抗原,用于实验感染大鼠血清抗体效价测定。同时与用汉城株（ＳＲ－１１）感染的Ｖｅｒｏ－Ｅ６细胞作抗原的间接免疫荧光法（以下简称ＩＦＡ）进行比较。ＷＢ法对３／４标本在大鼠接种病毒后第３天测得血清ＩｇＭ阳性,而ＩＦＡ法仅１／４标本出现阳性,ＩＦＡ效价为１：５１２０的血清,ＷＢ效价为１’：４０９６０,且在血清１：１０稀释时反应带亦清晰。两种方法分别测定６４份大鼠血清。甩ＩＦＡ法,４４份（６８．８％）出现类似阳性的荧光颗粒,而用ＷＢ法测定,无特异的反应带出现。非感染Ｖｅｒｏ－Ｅ６细胞作ＩＦＡ抗原,３０份（４６．９％）与正常细胞抗原有反应,此结果表明ＷＢ法在特异性和敏感性方面均高于ＩＦＡ法。ＩＦＡ法中的非特异性反应系血清与细胞成份之反应。     

不同月龄婴儿接种DTP后血清中百日咳抗体水平的观测

本文对比观察了２１３例２月龄、３月龄婴儿接种ＤＴＰ后百日咳抗体水平的变化,探讨了母传抗体对免后抗体增长的影响。结果表明２月龄、３月龄婴儿ＤＴＰ免疫后１个月和３个月血清中百日咳抗体达保护水平的百分率无显著性差异（ｘ￣２＝０．０３６,ｐ＞０．９;ｘ￣２＝０．３２７,ｐ＞０．５）,免后１个月抗体ＧＭＴ无显著性差异（ｔ＝０．１７,ｐ＞０．５）,免后３个月抗体ＧＭＴ３月龄组高于２月龄组（ｔ＝２．２２,ｐ＜０．０５）。我们还发现免前抗体水平与免后１个月ＧＭＴ虽有负相关（ｒ＝—０,７５４）的倾向,但总体上对抑制免后抗体应答不明显,因而建议将儿童ＤＴＰ基础免疫的起始月龄提前至２月龄进行。     

青霉素和NAA与6—BA配合在离体草莓器官建成中的作用

本实验研究了青霉素和ＮＡＡ与６－ＢＡ配合对离体草莓器官建成以及体内过氧化物同工酶的影响。结果表明：青霉素促进不定根的分化,但抑制不定根的伸长和不定芽的分化,并且不同程度地影响器官建成过程中过氧化和抽工酶的谱带和活性。青霉素与植物激素一样,参与了植物体内的生理代谢而引起植物器官建成。     

植食性同翅目昆虫寻找和接受植物韧皮部过程中的细胞与化学探试(英文)

植食性同翅目昆虫在最终接受其宿主植物的过程中,将感受从叶表层直到韧皮部筛管途中存在的多种化学物质,并导致不同的刺探和取食行为。本文就植物叶表层存在的糖类和生物碱类物质,叶肉层的多糖类、酸碱度和酚类物质以及韧皮部内的氨基酸、蛋白质、碳水化合物和植物次生物质等对昆虫寻找及取食韧皮部行为的影响作一综述,并且还探讨了植物叶肉层的细胞结构对昆虫刺探及取食行为的可能影响。此外,结合刺探电位(electrical penetration graphs,EPGs)的研究结果,还讨论了昆虫感受植物叶组织内部的各种化学和细胞结构信息的可能机制。     

无花果蛋白酶在阴离子交换树脂上的固定化

无花果蛋白酶通过８％戊二醛活化载体,共价结合到聚苯乙烯阴离子交换树脂ＧＭ２０１上,固定化作用在ｐＨ７．７,酶浓度０．８ｍｇ／ｇ树脂,４℃下进行６ｈ。得到的固定化酶表观Ｋ_ｍ值（酪蛋白,１．１１×１０~（－４）ｍｏｌ／Ｌ）小于溶液酶Ｋ_ｍ值（１．９６×１０~（－４）ｍｏｌ／Ｌ）;固定化酶活性在ｐＨ６～８保持稳定,溶液酶最适ｐＨ为７．２;固定化酶最适温度由溶液酶的５０～６０℃移至３７℃;固定化酶２５℃保持７ｄ,重复水解酪蛋白７次后,保留８３．３％活性。固定化酶对酪蛋白水解度达４７．５％,对大豆球蛋白达１１．６％。     

重组PAI－1对u－PA抑制活性的研究

利用大肠杆菌表达的重组纤溶酶原激活物抑制因子－１（ｒＰＡＩ－１）具有许多与天然ＰＡＩ－１相同的性质,ｒＰＡＩ－１对ｕ－ＰＡ抑制活性研究的内容包括：几种化学物质（盐酸胍、尿素、硫氰酸钾、ＳＤＳ、氯化钠等）对ｒＰＡＩ－１的激活作用、盐酸胍激活ｒＰＡＩ－１的浓度与温度效应、显色底物法和ＳＤＳ－ＰＡＧＥ纤维蛋白自显影对ｒＰＡＩ－１活性的测定、活性态ｒＰＡＩ－１向潜状态的转变及其与盐浓度和ｐＨ值的关系。     

家鸡和原鸡的线粒体DNA多态性比较

本文运用１１种限制性内切酶分析了家鸡（茶花鸡、尼西鸡、大理漾濞黄鸡）和原鸡共１０只个体的线粒体ＤＮＡ限制性片段长度多态性（ＲＦＬＰ）,平均每个个检测到的片段为４０条左右。但仅发现３种变异的限制性片制性格局,即ＳｔｕＩ－Ｂ,Ｅｃａ－Ｉ－ｂ和ＲＩ－Ｂ．其中ＳｔｕＩ－Ｂ和ＳｃａＩ－Ｂ为首次报道,而且均为原鸡所物有,ＥｃｏＲＩ－Ｂ则为大理漾濞黄鸡所特有。茶花鸡和尼西鸡拥有完全相同的限制性格局。经过计算,原     

Evidence for natural horizontal transfer of tetQ between bacteria that normally colonize humans and bacteria that normally colonize livestock.

Though numerous studies have shown that gene transfer occurs between distantly related bacterial genera under laboratory conditions, the frequency and breadth of horizontal transfer events in nature remain unknown. Previous evidence for natural intergeneric transfers came from studies of genes in human pathogens, bacteria that colonize the same host. We present evidence that natural transfer of a tetracycline resistance gene, tetQ, has occurred between bacterial genera that normally colonize different hosts. A DNA sequence comparative approach was taken to examine the extent of horizontal tetQ dissemination between species of Bacteroides, the predominant genus of the human colonic microflora, and between species of Bacteroides and of the distantly related genus Prevotella, a predominant genus of the microflora of the rumens and intestinal tracts of farm animals. Virtually identical tetQ sequences were found in a number of isolate pairs differing in taxonomy and geographic origin, indicating that extensive natural gene transmission has occurred. Among the exchange events indicated by the evidence was the very recent transfer of an allele of tetQ usually found in Prevotella spp. to a Bacteroides fragilis strain.     

Multiple genotypes of mitochondrial DNA within a horse population from a small region in Yunnan province of China

mtDNA genotypes of six domestic horses (three adult short horses whose heights are under 1 m and three common domestic horses) from a small region of 15 km² in Malipo county of Yunnan province of China were investigated by the technique of restriction fragment length polymorphism (RFLP) with 16 restriction endonucleases which recognize 6-bp sequences. An average of 56 fragments for an individual was obtained. Unlike other domestic animals, this population of horses exhibits high mtDNA genetic diversity. Each of the six horses has a specific mtDNA genotype showing a pattern of multiple maternal origins, as suggested by fossil and literature records. We think the population of horses is an amazing seed-resource pool of horses and hence deserves to be paid more attention from the view of conservation genetics. However, it is also remarkable that we did not find any typical mtDNA genetic markers which would discriminate between short horses and common domestic horses.