儿茶素类化合物的抗结核活性研究进展

近年来,耐多药结核病(multidrug-resistant tuberculosis,MDR-TB)的出现及人类免疫缺陷病毒(human immunodeficiency virus,HIV)与结核分枝杆菌合并感染日益增多,使结核病的防治面临更加严峻的挑战,人们急需开发新型抗结核药物及天然低毒的辅助治疗药物。绿茶中的儿茶素类化合物具有多种生物活性,对多种疾病有一定的辅助疗效。多项研究显示,儿茶素类化合物也具有抗结核活性,其机制包括抑制二氢叶酸还原酶活性、影响分枝菌酸及细胞壁的合成、下调富含色氨酸天冬氨酸的膜蛋白(tryptophan-aspartate containing coat protein,TACO)基因表达以抑制结核分枝杆菌的胞内寄生,降低氧化应激水平,下调结核分枝杆菌85B蛋白和宿主肿瘤坏死因子α(tumor necrosis factor α,TNF-α)表达,从而改善炎症水平。有研究显示,喝绿茶可降低结核分枝杆菌感染风险,儿茶素类化合物可辅助治疗结核病并与抗结核药物有协同治疗作用,但目前对其作用机制的研究还不够深入,需进一步探讨。     

生物碱成分常用显色剂及一种检测内酰胺的特效方法

薄层层析 (TLC)中 ,碘化铋钾和改良碘化钾试剂常作为生物碱成分 (天然和合成化合物 )的显色剂。本文对它们进行综述、分析 ,以期对生物碱成分的薄层层析提供参考。同时提供一种检测γ 内酰胺的特效方法。     

乌桕桕脂中甾醇和其他成分分离鉴定

通过柱层析、薄层层析等化学方法,从乌桕桕脂中分离得到甾醇及脂肪酸酯类化合物。经气相色谱和气-质连用分析,鉴定出下列化合物：β—谷甾醇、菜油甾醇、r7—豆甾烯醇,肉豆蔻酸甲酯、肉豆蔻酸乙酯、棕榈酸甲酯、硬酯酸甲酯和硬酯酸乙酯。     

乌桕桕脂中甾醇和其它成分分离鉴定

通过柱层析、薄层层析等化学方法,从乌桕桕脂中分离得到甾醇及脂肪酸酯类化合物。经气相色谱和气-质联用分析,鉴定出下列化合物:β-谷甾醇、菜油甾醇、Δ~7-豆甾烯醇、肉豆蔻酸甲酯、肉豆蔻酸乙酯、棕榈酸甲酯、硬酯酸甲酯和硬酯酸乙酯。     

抗酸分枝杆菌和相关菌全细胞枝菌酸甲基酯的薄层分析

用单向薄层层析方法对22种抗酸分枝杆菌及相关细菌的全细胞枝菌酸甲基酯进行了分析。结果表明,人型结核杆菌、牛型结核杆菌、堪萨斯分枝杆菌、海分枝杆菌和胃分枝杆菌的图谱特征相似,由a、甲氧基和酮基枝菌酸酯组成,还有两种未知成分I和J。微黄分枝杆菌、草分枝杆菌、鸟分枝杆菌．胞内分枝杆菌、蛙分枝杆菌和不产色分枝杆菌等均由带a、酮基和蜡脂枝菌酸组成。其它菌种的层析图谱各不相同。诺卡氏菌、红球菌和棒杆菌的图谱较分枝杆菌属简单,主要含有a枝菌酸,又因其Rf值不同,可以将这4种菌属区别开。从肺结核患者痰中分离出来的9株标本技菌酸图谱与标准人型结核扦菌相同,这和用标准化规程进行鉴定的结果一致。我们认为单向薄层层析对于抗酸分枝杆菌的分类和鉴定具有一定的意义。     

毛纺织品中辛硫磷含量的两种测定方法

辛硫磷作为纯毛纺织品的防蛀药剂,经一年试验已初步证实有效。为了找出辛硫磷合理使用的有效浓度,我们采用了薄层层析显色法和酶抑制法进行了测定,效果较好。可供有机磷农药残留量分析的参考。 一、薄层层析显色法 (一)提取 称毛织品2克(可根据辛硫磷含量而     

分枝杆菌枝菌酸合成及其调控

结核病是危害人类健康的重要传染病,每年200多万人死于结核病。耐(多)药菌株的出现、与HIV共感染以及人口老龄化等原因与全球结核病的卷土重来密切相关。枝菌酸是存在于结核分枝杆菌、其他分枝杆菌和许多放线菌的细胞壁中的关键组分,与结核分枝杆菌的致病、毒力和免疫逃避都有关系。枝菌酸在抗结核研究中有着极其重要的地位。结核分枝杆菌枝菌酸的生物合成途径一直是很重要的抗结核药物靶标,异烟肼、乙胺丁醇等抗结核药物都是以此为靶标。深入研究枝菌酸的合成、调控有助于发现更多的药物靶标,为开发结核病控制新措施提供基础。本文综述了结核分枝杆菌枝菌酸的结构与分类、生物合成途径及其调控、作为抗结核药物靶标的前景与应用,以期对枝菌酸有更深入的了解并为新型抗结核药物靶标的发现提供基础。     

从大容量噬菌体抗体库中筛选抗Acr蛋白人源单链抗体

目的:从天然的大容量噬菌体抗体库中筛选特异的抗结核分枝杆菌晶体蛋白( alpha-crystallin Acr)的人源抗体.方法:以结核分枝杆菌Acr蛋白包被免疫管,通过对噬菌体抗体库进行4轮“吸附-洗脱-扩增”的过程从大容量抗体库中筛选特异性抗结核分枝杆菌Acr蛋白的抗体,并对可变区序列进行了测序分析.将特异性的噬菌体抗体感染HB2151菌,经IPTG诱导表达,制备了抗结核分枝杆菌Acr蛋白的可溶性单链抗体;对其序列和抗原结合活性进行分析鉴定.结果:经过4轮筛选,获得了43个与结核分枝杆菌Acr蛋白结合的阳性克隆,其中29个特异结合的克隆;测序分析有26不同的可变区片段;通过可溶性单链抗体(scFv)表达筛选到14株特异性结合Acr蛋白的可溶性单链抗体克隆;经过基因测序,分析了可变区基因的亚群.成功制备了可溶性单链抗体.Westren blotting分析证实筛选的人源单链抗体能与天然蛋白结合.结论:利用单链大容量抗体库获得抗结核分枝杆菌Acr蛋白的噬菌体抗体并且成功制备抗结核分枝杆菌Acr天然蛋白的可溶性单链抗体,为今后的研究和应用奠定基础.     

蛋白质组学在结核分枝杆菌研究中的应用

蛋白质组学是在基因组学基础上发展起来的新兴学科, 其基本技术包括样品制备、蛋白质分离和蛋白质鉴定分析, 其中的核心技术是双向凝胶电泳技术(2-Dimensional Electrophoresis, 2-DE)和质谱技术(Mass Spectrometry, MS)。近年来, 蛋白质组学技术已应用于结核分枝杆菌的研究领域。应用蛋白质组学技术分离、鉴定、检测结核分枝杆菌致病株的全菌蛋白及分泌蛋白, 分析其蛋白组成, 可深入解析结核分枝杆菌的致病机理和耐药机制。通过对结核分枝杆菌致病株抗原的分析, 为研制预防结核病的新型疫苗拓展了空间。通过对结核分枝杆菌临床分离株的蛋白组成分析还发现了一些有意义的结核病早期诊断标志物。蛋白质组学技术还应用于寻找新的药物靶标, 在研制和筛选新的抗结核药物等方面展示了一些有价值的研究成果, 为更好地开展结核病的预防、早期诊断及治疗打下了基础。     

纤维素板微量氨基酸的分离及几种显色方法的比较

氨基酸分析是研究蛋白质化学的最基本的实验技术之一。现在已经普遍地使用离子交换层析、纸层析、纸电泳、薄层层析等方法分离、分析氨基酸。其中自动化的离子交换层析方法分析具有快速、微量和准确等特点,但需要昂贵的仪器设备,在一般实验室里不易办到。纸层析和薄层层析的方法,设备要求简单,操作方便,操作熟练时也可达到定量的要求。也可以用纤维素薄层层析的方法分离分析氨基酸,并已用于尿和血样品以及其他蛋白质中的氨基酸测定。经我们初步摸索,使用一种小型的纤维素板层析,并将茚三酮试剂直接加入展层溶剂中,蛋白质经酸水解后,可得到完全分开的普通     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.