星海链霉菌抑菌活性物质的分离纯化

星海链霉菌(Streptomyces xinghaiensis)是从大连星海湾海泥样品中分离的海洋链霉菌新种,其发酵液具有广谱抗菌活性。研究该菌株的发酵液对临床分离的耐药菌的抑制活性,发现星海链霉菌发酵液对鲍曼不动杆菌和耐甲氧西林金黄色葡萄球菌菌株具有抑制活性。采用SPE、大孔吸附树脂HP-20、葡聚糖凝胶Sephadex LH-20、HPLC、TLC等对抗耐甲氧西林金黄色葡萄球菌的物质进行了活性追踪,发现活性物质为弱碱性水溶性成分,无特征紫外吸收,可被茚三酮显色,推断活性物质可能为氨基糖苷类化合物。对星海链霉菌基因组序列进行初步分析,发现一个与核糖霉素生物合成基因簇相似性较高的基因簇,但TLC分析结果表明,活性化合物与核糖霉素不同。     

铜绿假单胞菌体外抑菌活性研究

目的 观察铜绿假单胞菌抗菌物质对鲍曼不动杆菌等细菌的体外抑菌效果.方法 用交叉条带实验方法检测了铜绿假单胞菌对鲍曼不动杆菌、耐甲氧西林表皮葡萄球菌和粪肠球菌的体外抑制活性.结果 铜绿假单胞菌对鲍曼不动杆菌、耐甲氧西林表皮葡萄球菌和粪肠球菌体外抑菌活性良好,10株铜绿假单胞菌中,有8株对鲍曼不动杆菌的抑制率均达到了100％.另外有8株对耐甲氧西林表皮葡萄球菌的抑菌率均为100％;有6株对粪肠球菌的抑菌率为100％.结论 铜绿假单胞菌对上述3种致病菌具有较强的抗菌活性,具有开发前景.     

美洲大蠊肠道内生放线菌抗金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌活性分析

昆虫肠道共生放线菌作为一种特境放线菌,因与土壤中的放线菌生存环境的不同,研究其种类和抗菌活性具有重要意义.将金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌(Methicillin-resistant Staphylococcus aureus,MRSA)这两种致病菌作为指示细菌,对分离自美洲大蠊Periplaneta ame...     

地胆草与白花地胆草脂溶性成分的GC-MS分析及抑菌活性研究

采用溶剂萃取法提取地胆草(Elephantopusscaber Linn.)和白花地胆草(Elephantopustomentosus Linn.)的脂溶性成分,经GC-MS分析,从地胆草中鉴定出44种化学成分,占总脂溶性成分的93.72%;从白花地胆草中鉴定出25种化学成分,占总脂溶性成分的82.08%。地胆草和白花地胆草在萜类成分含量具有显著性差异。通过滤纸片琼脂扩散法测试其抗菌活性,结果表明地胆草与白花地胆草的脂溶性成分对耐甲氧西林金黄色葡萄球菌(MRSA)和金黄色葡萄球菌均有抑制活性,且白花地胆草的抑菌活性强于地胆草。     

mecA、femA基因与MRSA及MRCNS的相关性研究

耐甲氧西林金黄色葡萄球菌(MRSA)及耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)是引起医院和社区人群感染的主要病原菌。由于其异质性和多重耐药,使临床治疗非常棘手。对m ecA与femA基因及耐药性的相关研究,在临床用药和防止播散意义重大。     

酸模内生镰刀菌HU0298抗MRSA活性代谢成分

从酸模Rumex acetosa内生真菌Fusarium sp.HU0298玉米发酵物的活性流分中分离鉴定了一个主要成分:亚油酸;结合活性流分的气相色谱(GC)组分分析和活性评价发现亚油酸是该发酵物的主要抗耐甲氧西林金黄色葡萄球菌(MRSA)成分;通过对亚油酸和多个其他脂肪酸标准品的活性测试探究了脂肪酸化学结构和与抗M...     

铜绿假单胞菌抗菌物质对耐甲氧西林金黄色葡萄球菌的抑菌活性研究

目的观察铜绿假单胞菌抗菌物质对耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcusaureus,MRSA)的体外抑菌活性。方法用交叉划线接种方法进行铜绿假单胞菌对32株耐甲氧西林金葡菌的体外抗菌活性的测定。结果铜绿假单胞菌抗菌物质对MRSA的体外抑菌活性良好,产生色素的菌株的抗菌活性最好,15株铜绿假单胞菌中,7株产蓝绿色色素的铜绿假单胞菌,对MRSA的抑制率均达到了100%,平均抑菌带的宽度为37.7 mm。结论铜绿假单胞菌抗菌物质对32株MRSA具有较强的抗菌活性,无疑对MRSA感染的抗菌药物研制方面开辟了一条新的途径。这是国内的首次研究报道。     

具有破坏细胞壁功能的海因类化合物在体外与体内作用机理

咪唑烷二酮(Hydantoin)衍生物如呋喃妥因,因其为小分子且具有低的细菌耐药率而引起了广泛关注。然而,它们的中等强度抗菌活性可能会阻碍它们在长期抗药性方面的应用。本研究设计了具有细菌膜活性的乙内酰脲衍生物,临床检验发现,其对革兰氏阳性和阴性菌比呋喃妥因显示出更有效的抗菌活性。这些化合物能够作用于细菌膜,类似于天然宿主防御肽。此外,在特定的测试条件下,这些乙内酰脲化合物不仅能迅速杀死细菌病原体而且防止耐甲氧西林金黄色葡萄球菌细菌耐药性的发展。更有意义的是,对于由耐甲氧西林金黄色葡萄球菌引起的大鼠肺炎,该化合物在体内发挥的抑制细菌和炎症消除的疗效明显优于万古霉素,显示出其潜在的治疗价值。     

氯氰碘柳胺与环丙沙星对耐甲氧西林金黄色葡萄球菌的体外联合药敏试验分析

目的 评价氯氰碘柳胺与环丙沙星联用对60株环丙沙星均为耐药的耐甲氧西林金黄色葡萄球菌(MRSA)的体外抗菌效应.方法 采用棋盘法设计,微量肉汤稀释法测定不同浓度组合的抗菌药物对60株甲氧西林耐药的金黄色葡萄球菌(MRSA)的最低抑菌浓度,并计算部分抑菌浓度指数(FICI)判定联合效应.结果 氯氰碘柳胺与环丙沙星联合用药后,其FICI分布:FIC≤0.5为20.0％,0.5 ＜FIC≤1为66.7％,1＜FIC≤2为13.3％,FIC＞2为0.结论 体外氯氰碘柳胺与环丙沙星联用对60株耐甲氧西林金黄色葡萄球菌的作用主要为相加和协同作用.     

桐花树活性内生真菌筛选及其抗菌化学成分的研究

为了探究桐花树内生真菌在抑菌方面的价值,该文以内生真菌发酵产物的抑菌作用为评价指标筛选活性菌株,采用生物活性跟踪方法结合多种色谱技术分离活性菌株的化学成分,通过波谱与文献数据比对鉴定单体化合物结构,并利用微孔板法测定单体化合物的抑菌活性。结果表明:(1)从桐花树分离得到的16株内生真菌分属2纲7目10科10属,镰刀菌属(Fusarium)为优势菌属。内生真菌GXIMD02029和GXIMD02039的发酵产物对枯草芽孢杆菌、表皮葡萄球菌、耐甲氧西林金黄色葡萄球菌、藤黄微球菌、粘性放线菌和金黄色葡萄球菌有不同程度的抑制作用,GXIMD02038发酵产物对耐甲氧西林金黄色葡萄球菌、藤黄微球菌和金黄色葡萄球菌有抑制作用。(2)7个化合物从内生真菌Phomopsis sp. GXIMD02029中被分离并鉴定为(15R)-acetoxydothiorelone A(1)、cytosporone B(2)、pestalotiopsone H(3)、pestalotiopsone B(4)、4-Hydroxybenzaldehyde(5)、p-Hydroxybenzoic acid(6)、N-(2-phenylethyl)acetamide(7)。(3)化合物1和2有不同程度的抑菌作用,化合物1对枯草芽孢杆菌、表皮葡萄球菌、耐甲氧西林金黄色葡萄球菌的MIC值为16.25 SymbolmA@ g·mL^-1,对藤黄微球菌和粘性放线菌的MIC值为7.812 5 SymbolmA@ g·mL^-1,对金黄色葡萄球菌的MIC值为31.25 SymbolmA@ g·mL^-1。化合物2对藤黄微球菌的MIC值为62.5 SymbolmA@ g·mL^-1,对枯草芽孢杆菌、表皮葡萄球菌、耐甲氧西林金黄色葡萄球菌、粘性放线菌的MIC值为125 SymbolmA@ g·mL^-1,对金黄色葡萄球菌的MIC值为250 SymbolmA@ g·mL^-1。该文筛选了3株活性菌株,首次报道化合物1具有抗菌活性,为桐花树内生真菌在抗菌价值方面提供了依据。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism