细胞壁缺陷对白喉棒状杆菌致病性影响的研究

检测白喉棒状杆菌稳定L型对动物的致病性,探讨细胞壁缺陷对白喉棒状杆菌致病性的影响及其可能的分子机制。采用氨苄青霉素在非高渗培养基内诱导并获得产毒性白喉棒状杆菌稳定L型纯培养物。收集白喉棒状杆菌稳定L型纯培养物及其代谢产物,将收集的高于细菌型10 000倍浓度的白喉棒状杆菌稳定L型纯培养物及其代谢产物皮内注射家兔,观察局部注射部位皮肤或全身的病理改变。分别采用对流免疫电泳(CIEP)和SDS-不连续聚丙烯酰胺凝胶电泳(SDS-PAGE)检测白喉棒状杆菌稳定L型可溶性代谢产物中的白喉毒素蛋白质。结果显示,白喉棒状杆菌稳定L型不能引起动物局部或全身发生异常表现,在其可溶性代谢产物中并未检测到白喉毒素蛋白质。提示细胞壁缺陷变异可影响白喉棒状杆菌产生白喉毒素蛋白质,从而使其丧失了产生外毒素致病的作用。     

聚合酶链反应-单链构型多态性检测细胞壁缺陷型淋病奈瑟菌cppB基因变异

目的：检测与分析淋病奈瑟菌L型的cppB基因,探讨细胞壁缺陷对淋病奈瑟菌cppB基因的影响。方法：用青霉素诱导淋病奈瑟菌成为L型并获得稳定L型纯培养物,用cppB基因特异性引物以聚合酶链反应(PCR)检测稳定L型纯培养物的cppB基因和进行单链构型多态性(SSCP)分析。结果：淋病奈瑟菌的细菌型及其L型都具有cppB基因扩增产物,但PCR—SSCP分析可见异常泳动DNA带型(细菌型有2条带、L型有3条带)。结论：细胞壁缺陷淋病奈瑟菌仍然具有cppB基因,但其碱基序列可以发生改变。     

细菌L型对化学因素敏感性研究

本文研究了伤寒沙门氏菌、葡萄球菌及白喉棒状杆菌L型对化学消毒剂、细菌生长抑制剂、酸和碱的敏感性,并与其亲代细菌型作了比较。结果表明:细菌L型对表面活性剂、酚剂、重金属盐、脱水剂、卤素及氧化剂的敏感性明显(P<0.05)或不明显(P>0.05)增加,伤寒沙门氏菌L型对龙胆紫、玫瑰色酸、胆盐及酸的敏感性增高,葡萄球菌及白喉棒状杆菌L型对龙胆紫、玫瑰色酸、胆盐及酸的敏感性降低,伤寒沙门氏菌及白喉棒状杆菌L型对碱敏感性降低。     

细胞壁缺陷型淋病奈瑟菌cppB基因的检测

目的：了解细胞壁缺陷对淋病奈瑟菌隐蔽性质粒B基因（cppB）的影响。方法：用青霉素诱导林病奈瑟菌成L型,以非高渗液体培养基传代培养并获得L型纯培养物,用cppB基因特异性引物以聚合酶链反应（PCR）检测不同代次稳定L型纯培养物的cppB基因。结果：淋病奈瑟菌细菌型及其传1-4代的L型培养物具有cppB基因,传5代后的L型培养物不能检出cppB基因。结论：细胞壁缺陷可造成淋病奈瑟菌隐蔽性质粒丢失,导致cppB基因PCR检测漏诊。     

细菌L型与宿主内环境的相互作用

细菌L型是指细菌在某些不利因素的作用下发生变异而形成的细胞壁缺陷型。细菌L型可用青霉素等作用细胞壁的诱导剂在体外诱导形成,但也可发生在动物和人体内。近年许多报导证明细菌L型与败血症、迁延性感染和慢性炎症性疾患有较密切的关系。临床医生已开始重视细菌     

沙门菌CWDMs脂代谢检测

采用毛地黄皂苷敏感试验和菌细胞胆固醇、甘油三脂及胆碱酯酶定性与定量分析法,检测伤寒杆菌和甲型副伤寒杆菌经L 型变异后形成的细胞壁缺陷突变株(CW DM )的脂类代谢活性,了解这些CW DM 变异的性质和探讨细菌细胞壁缺陷突变与细菌演变的关系。结果表明,沙门菌CW DM s 具有显著的胆固醇和甘油三脂代谢活性、对毛地黄皂苷高度敏感并且还具有与白色念珠菌相似的胆固醇和甘油三脂的含量,但未能检出胆碱酯酶活性。CW DM s返祖菌丧失了脂类代谢酶类和胞浆膜不含胆固醇,恢复了与其亲代细菌型相似的代谢特征。提示在沙门菌天然即存在有与脂类及胆固醇代谢相关的基因,细胞壁的缺陷导致这些脂类及胆固醇代谢基因活化,以致 CW DM s 能够表达固醇和甘油三脂代谢活性和胞浆膜含有胆固醇     

细胞壁缺陷结核分支杆菌致细胞病变作用的观察

目的：探讨细胞壁缺陷结核分支杆菌的致细胞病变作用。方法：用利福平诱导结核分支杆菌形成稳定L型后感染Vero细胞,直接在显微镜下和抗酸染色观察细胞病变情况以及结核分支杆菌同宿主细胞的关系。结果：Vero细胞受结核分支杆菌L型感染72h后形成空泡、变圆、脱落和裂解,结核分支杆菌稳定L型细胞粘附或侵入细胞内。结论：细胞壁缺陷结核分支杆菌仍然能够引起Vero细胞发生病变但致细胞病变的作用较其亲代细菌型明显减弱,L型能够粘附于宿主细胞表面或进入宿主细胞内生长繁殖,引起缓慢的细胞病变。     

细菌稳定L型返祖性的研究

营养琼脂培养的白喉杆菌、葡萄球菌、伤寒杆菌及甲型副伤寒杆菌的稳定L型经硬琼脂,20%血清琼脂,血琼脂及12%,20%,30%明胶培养基传代培养或注射动物体内均不能返祖。但L型—细菌型接触培养具有促沙门氏菌L型返祖作用,可能同细菌型的某种“促返祖因子”传递给L型有关。     

细菌L型和一些肠道杆菌的电动力学研究

用电泳法研究了细菌Ｌ型及其亲代细菌型和一些肠道杆菌的电动力学特征。伤寒杆菌Ｌ型和葡萄球菌Ｃｏｗａｎ株Ｌ型的等电点与其亲代细菌型不同;普通大肠杆菌、普通变形杆菌的等电点与革兰氏阳性菌相似;白喉杆菌Ｌ型和葡萄球菌Ｗｏｏｄ株Ｌ型的等电点与其亲代细菌型无显著差异。电泳可使结晶紫染色的细菌脱去结晶紫,亦可使染色后经乙醇处理的普通大肠杆菌和伤寒杆菌脱色并在电场作用下泳动,但不能使染色后经乙醇处理的葡萄球菌脱色或泳动,痢疾杆菌、伤寒杆菌和肠道致病性大肠杆菌的等电点不同于普通大肠杆菌和普通变形杆菌;在一定ｐＨ范围内,电泳     

细菌L型常见的一种多形性—类白喉样形态

细菌Ｌ型是细菌的细胞壁缺陷型。因为缺壁故形态多变，常呈现大小不等的球状、膨大的杆状、细长的丝状。本室曾多次从临床标本分离，发现细菌Ｌ型有呈类白喉样形态，易误认为类白喉杆菌，现以两个临床实例检查加以说明。病例１患者，男，３０岁，慢性颈淋巴结炎，取咽拭子...     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

医疗机构合理用药评价模型的构建研究

目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.