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1.
牙龈类杆菌曾是重要的产黑色素类杆菌群菌株,最近重新命名为牙龈卟啉杆菌,该菌为牙周病龈下菌斑中关键性厌氧菌,与成人慢性牙周炎的发生、发展有密切关系。作者用牙龈卟啉杆菌侵袭型菌株W83,作为免疫原,通过免疫小鼠、细胞融合、筛选、克隆化,最后得到一株能够稳定分泌抗牙龈卟啉杆菌W83的单克隆抗体杂交瘤细胞系,经鉴定该单抗特异性良好,可用于临床该菌的检出和生态学研究。  相似文献   
2.
钟炎皋  相梅芳 《蛇志》1993,5(1):7-9
应用蝮蛇抗栓酶治疗小儿脑炎致急性偏瘫共25例。沿疗前后检测血中的6-K-PGF_1x及 TXB_2.结果表明:治疗后血中 6-酮-前列腺素 F_1x 明显增高,血栓素 B_2明显降低。推测蝮蛇抗栓酶之所以具有去纤、溶栓、扩血管等作用,可能与血中前列腺素、血栓素 B_2水平变化有关。  相似文献   
3.
Nutrient enrichment effects on biofilm metabolism in a Mediterranean stream   总被引:1,自引:0,他引:1  
1. Biofilm biomass and metabolism were analysed in La Solana, a calcareous, undisturbed second-order stream. Measurements were carried out in two Mediterranean climatic extremes, summer and winter. Two on-site experimental channels were used to study changes following nutrient addition to one of them. 2. Algal biomass (chlorophyll a), NDPP (net daily primary production), GDPP (gross daily primary production) and R (respiration) increased in the enriched channel, and these increases were greater in summer. 3. Photosynthetic capacity (Pmaxchl) decreased during summer, possibly due to enhanced self-shading accompanying the increase in biomass. 4. In winter, Pmaxchl increased and reached values similar to those in the summer control channel. Because grazing was low, the higher values of Pmaxchl were attributed to partial substitution of the cyanobacterial assemblage by a green-algae dominated assemblage with higher photosynthetic capacity as well as the low increase in biomass preventing any significant self-shading.  相似文献   
4.
1. The three‐spined stickleback (Gasterosteus aculeatus) on the Iberian Peninsula is only distributed in freshwater habitats and has completely disappeared from most of its range, mainly as a consequence of habitat degradation and invasive fish introductions. Genetic investigations have shown that Mediterranean‐Adriatic sticklebacks constitute an evolutionarily significant unit. Here, we present the first genetic data for Iberian populations living on the southern edge of the stickleback’s range. We used microsatellite markers to study gene diversity, population structure and genetic demography of stickleback populations. 2. High genetic differentiation among collections yielded a model of four genetically homogeneous units related to geography. The observed pattern of isolation by distance resulted mainly from the hydrographical pattern and limited gene flow among rivers. Moreover, low levels of gene diversity, high isolation and recent bottleneck events, which have led to small or even critical effective population sizes in several locations, could be explained by additional recent anthropogenic fragmentation. 3. We defined at least four evolutionarily significant units threatened by habitat fragmentation in north‐eastern Iberian sticklebacks. Because they retain long evolutionary histories, these populations should be considered of high conservation priority, and urgent management measures should be implemented.  相似文献   
5.
INTRODUCTIONHepatitis B virus (HBV) infection is the mostcommon viral infection in humans especially inChina and East Asia. At present, the most effi-cient method to control the disease is vaccinationof new-borns. Both blood derived vaccine and re-combinant vaccine are hepatitis B surface alltigen(HBsAg)-based and useful in the prevention of thedisease[1-3]. HBsAg could evoke protective humoralimmune response in vivo, but the immune memoryonly last for 5 years or so[3, 4]. How to des…  相似文献   
6.
细蠓属一新种记述(双翅目:蠓科)   总被引:3,自引:0,他引:3  
本文记述宁夏回族自治区银川市平吉堡地区吸血双翅目蠓科细蠓属1新种:以新细蠓Leptocomops yixini,sp.nov。模式标本保存在兰州军区军事医学研究所标本室。  相似文献   
7.
8.
细胞粘附分子(CAM)可介导细胞间及细胞与间质之间的相互作用并传导信息,参与机体胚胎发育、免疫调节、炎症反应、组织修复及肿瘤转移等生理和病理过程。细胞间粘附分子1(ICAM1)是主要的CAM分子之一,可表达于活化的细胞,内皮细胞等。人膜是母体与胚胎滋养层直接接触的特殊组织、已发现蜕膜细胞在着床过程中参与了局部免疫耐受的形成,但对着床期ICAM1在蜕膜细胞表达的动态研究鲜见报道。本研究采用免疫荧光、多参数流式细胞术,分别从整体和局部角度、着床过程中外周血淋巴细胞(PBLC)及子宫内膜/蜕膜(EC/DC)细胞ICAM1的不同表达特点进行了动态观察和对比性分析。结果发现,ICAM1在着床期PBLC及EC/DC中的表达均存在明显的动态变化(Tab.1;Figs.1&2)。ICAM1在PBLC中的表达于妊娠第一天(D1)即开始降低,D2降至最低;与此不同,ICAM1在EC/DC中的表达于D2开始降低,D4降至最低,D5开始恢复,但尚未恢复到对照水平。结果表明,ICAM1在蜕膜局部的表达调节方式不同于外周血;ICAM1表达阳性的外周血,淋巴细胞和蜕膜细胞均代表着活化的功能性细胞,这些细胞表面ICAM  相似文献   
9.
鸡IL-18成熟蛋白基因的克隆及分子进化分析   总被引:1,自引:0,他引:1  
根据已发表的鸡白介素18(IL-18)基因序列设计合成引物,以植物凝集素(PHA)和脂多糖(LPS)激活的AA肉鸡脾细胞mRNA为模板,通过RT-PCR扩增出编码鸡IL-18成熟蛋白的eDNA。将该eDNA克隆于pUCm-T载体,并对其进行测序,结果表明所克隆的核苷酸片段包含了全部成熟蛋白编码基因,成熟蛋白编码区507个核苷酸,编码169个氧基酸。把该基因编码的鸡成熟IL-18蛋白氨基酸序列与已公布的禽及哺乳动物IL-8成熟蛋白基因氧基酸序列进行比较,其同源性分别在96.5%~100%和20.1%~26.6%之间,分子系统进化树分析表明鸡IL-18与哺乳动物IL-18有共同的祖先,亲源关系较近,但在免疫系统选择性压力下,形成独特的种族特异性。鸡IL-18基因的克隆为体外表达鸡IL-18蛋白及作为免疫佐剂应用于预防接种的研究奠定了基础。  相似文献   
10.
SUMMARY.
  • 1 The composition and abundance of diatom assemblages were studied together with physiographical and physicochemical variables in twenty-eight springs in the Central Pyrenees during the period 1987–88.
  • 2 Characteristic groupings of diatom taxa are revealed by Principal Components Analysis. One group, made up of assemblages of the taxa Navicula cincta, Caloncis spp. and Niizschia elliptica, is characteristic of springs with waters of high ionic strength. Certain diatom taxa are characteristic of hard water springs, either in quiet waters (Denticula tenuis, Achnanthes minutissima, Eunotia spp.) or fast flowing ones (Fragilaria spp., Diatoma hiemale). Other taxa are representative of relatively quiet, softwater springs: Anomoeoneis bracfiysira, Tabellaria flocculosa, Aulacoseira distans and Fragilaria vaucheriae.
  • 3 Five different spring types were identified, with respect to diatom assemblages, using discriminant analysis. The first consisted of high mountain springs with cold, fast waters and low ionic strength. The second group, distributed throughout the Pyrenees, had similar environmental characteristics to the first group but with intermediate water velocity and slightly higher mineral content. The third contained springs in calcareous regions of the Pyrenees, mainly slow-flowing and with hard waters. The fourth was composed of softwater springs, whilst the fifth consisted of two springs which were subject to stressful conditions (limitation of light, abundance of nitrates or high salinity).
  • 4 Ionic strength and current velocity appeared to be the dominant environmental factors affecting diatom distribution in Pyrenean springs. These factors also seem to determine diatom communities in some other geographical areas. In some springs, however, peculiar environmental factors (dim light, salinity, and high temperature) affect the structure of diatom assemblages.
  相似文献   
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