炭疽芽胞杆菌(Bacillus anthracis)检测质粒的构建及其应用

根据炭疽芽胞杆菌(Bacillus anthracis)毒性质粒pX01和pX02上的2个毒力相关基因cya和capA的序列特点,以pIJ2925为出发载体,采用一步重叠延伸PCR技术(One-step Overlap Extension PCR,简称OOE-PCR)构建了包含cya基因和capA基因保守区DNA片段的炭疽检测质粒pBIB2006。采用复合PCR对模拟炭疽危险品进行分析,结果表明pBIB2006可以为炭疽芽胞杆菌的检测提供准确、安全和方便的阳性参照品,从而为检测炭疽芽胞杆菌和炭疽芽胞杆菌灭活疫苗提供了便利。     

苏南乡村生态植物景观营造

乡村生态植物景观营造是乡村景观建设的重要内容。本文以模拟自然、半自然植物群落为基础,对乡村生态植物景观营造进行了研究。根据乡村景观的构成要素,可以将乡村植物景观划分为村落植物景观(农户外环境植物景观)、农田植物景观、道路植物景观和水域河道植物景观;生态植物景观营造可以从自然群落中得到借鉴,以常熟为例,采用植被生态学的调查和分析方法对当地自然、半自然植物群落进行了研究,模拟形成15个可供当地应用的人工配植模式;乡村不同植物景观类型具有各自的特色和功能要求,通过分析常熟典型乡村特点,以模拟自然群落为基础,可进一步改造形成适于不同类型的乡村植物景观配植模式。     

Parasites paralyze cellular host defense system to promote virulence

To promote their survival, intracellular pathogens must confront microbicidal activities induced by interferons. In this issue of Cell Host & Microbe, Fentress et?al. show that Toxoplasma gondii evades intracellular killing by deploying a virulence determinant, ROP18, which acts by directly phosphorylating and disabling an IFN-γ-inducible immunity-related GTPase involved in pathogen clearance.     

帕金森病的临床治疗概况

帕金森病(Parkinson's disease, PD),在医学上称为"原发性震颤麻痹",又称"震颤麻痹",是一种中枢神经系统变性疾病,主要是因位于中脑部位"黑质"中的多巴胺(DA)能神经元病理性改变后,多巴胺的合成减少,对与其功能相互拮抗的乙酰胆碱的抑制功能降低,则乙酰胆碱的兴奋作用相对增强。两者失衡的结果便出现了"震颤麻痹"。本综述先从PD发病机制方向总结归纳目前临床常用的西医药物(包括左旋多巴、DA降解酶抑制剂、DA受体激动剂、抗胆碱能药物)、基因治疗靶点、手术治疗(脑深部电刺激术)及物理疗法,又从中医角度整体介绍了目前中医中药治疗以及针灸治疗等。因PD对患者的日常生活及身心健康造成了严重影响,我们希望通过本综述为PD综合治疗提供更广阔的临床思路及更好的方案。     

准分子激光双面式切削原位角膜磨镶术的研究进展

准分子激光双面式切削原位角膜磨镶术(Both-sided LASIK,BSL)是准分子激光原位角膜磨镶术(laser in situ keratomileusis, LASIK)的改良,BSL将部分激光切削分布在角膜瓣基质面,因而减少了对角膜基质床的切削,最大限度的保留了角膜基质床的剩余厚度,为降低术后角膜膨出提供可能,对屈光度相对偏高和/或角膜相对偏薄的患者,尽量增加手术的安全性,并为LASIK术后屈光回退的增强手术提供了一种新的方法。本文对近年BSL的研究进展作一综述。     

Diverse peptide presentation of rhesus macaque major histocompatibility complex class I Mamu-A 02 revealed by two peptide complex structures and insights into immune escape of simian immunodeficiency virus

Major histocompatibility complex class I (MHC I)-restricted CD8(+) T-cell responses play a pivotal role in anti-human immunodeficiency virus (HIV) immunity and the control of viremia. The rhesus macaque is an important animal model for HIV-related research. Among the MHC I alleles of the rhesus macaque, Mamu-A 02 is prevalent, presenting in ≥20% of macaques. In this study, we determined the crystal structure of Mamu-A 02, the second structure-determined MHC I from the rhesus macaque after Mamu-A 01. The peptide presentation characteristics of Mamu-A 02 are exhibited in complex structures with two typical Mamu-A 02-restricted CD8(+) T-cell epitopes, YY9 (Nef159 to -167; YTSGPGIRY) and GY9 (Gag71 to -79; GSENLKSLY), derived from simian immunodeficiency virus (SIV). These two peptides utilize similar primary anchor residues (Ser or Thr) at position 2 and Tyr at position 9. However, the central region of YY9 is different from that of GY9, a difference that may correlate with the immunogenic variance of these peptides. Further analysis indicated that the distinct conformations of these two peptides are modulated by four flexible residues in the Mamu-A 02 peptide-binding groove. The rare combination of these four residues in Mamu-A 02 leads to a variant presentation for peptides with different residues in their central regions. Additionally, in the two structures of the Mamu-A 02 complex, we compared the binding of rhesus and human β(2) microglobulin (β(2)m) to Mamu-A 02. We found that the peptide presentation of Mamu-A 02 is not affected by the interspecies interaction with human β(2)m. Our work broadens the understanding of CD8(+) T-cell-specific immunity against SIV in the rhesus macaque.     

Microbiological and production characteristics of the high-temperature Kongdian bed revealed during field trial of biotechnology for the enhancement of oil recovery

Microbiological technology for the enhancement of oil recovery based on the activation of the stratal microflora was tested in the high-temperature horizons of the Kongdian bed (60 degrees C) of the Dagang oil field (China). This biotechnology consists in the pumping of a water-air mixture and nitrogen and phosphorus mineral salts into the oil stratum through injection wells in order to stimulate the activity of the stratal microflora which produce oil-releasing metabolites. Monitoring of the physicochemical, microbiological, and production characteristics of the test site has revealed large changes in the ecosystem as a result of the application of biotechnology. The cell numbers of thermophilic hydrocarbon-oxidizing, fermentative, sulfate-reducing, and methanogenic microorganisms increased 10-10 000-fold. The rates of methanogenesis and sulfate reduction increased in the near-bottom zone of the injection wells and of some production wells. The microbial oil transformation was accompanied by the accumulation of bicarbonate ions, volatile fatty acids, and biosurfactants in the formation waters, as well as of CH4 and CO2 both in the gas phase and in the oil. Microbial metabolites promoted the additional recovery of oil. As a result of the application of biotechnology, the water content in the production liquid from the test site decreased, and the oil content increased. This allowed the recovery of more than 14000 tons of additional oil over 3.5 years.