正交实验法优选鹿角的水提工艺

目的：研究鹿角水煎煮工艺．优选最佳提取工艺条件。方法：以浸出物及总氮为检测指标，用正交实验考察3种因素(加水量、煎煮次数、煎煮时间)对其含量的影响。结果：鹿角的最佳提取工艺条件为加8倍量水，煎煮3次，3h／次。结论：制备工艺合理。     

感染性疾病与人类基因组研究进展

病原体感染后,机体对其清除能力以及疾病的转归,在很大程度上取决于个体间基因组的差异.研究发现,人类白细胞抗原(HLA)、细胞因子(CK)、甘露糖结合蛋白(MBL)、维生素D受体(VDR)、红细胞抗原等基因与感染性疾病的易感性有关.此文就近年来该研究领域的进展作了综述.     

感染性疾病与人类基因组研究进展

病原体感染后,机体对其清除能力以及疾病的转归,在很大程度上取决于个体间基因组的差异.研究发现,人类白细胞抗原(HLA)、细胞因子(CK)、甘露糖结合蛋白(MBL)、维生素D受体(VDR)、红细胞抗原等基因与感染性疾病的易感性有关.此文就近年来该研究领域的进展作了综述.     

基因组研究和后基因组研究

对人类基因的研究是人类对自身基因逐渐增加认识的基础上产生的需要和行为。“基因是大多数疾病的主要病因”的观点改变了整个生物学和医学研究的格局,而基因组学则是改变了基因研究“零敲碎打”的局面,从整体上阐明人类基因组。由此策略产生的人类基因组计划主要的成果是:遗传图、物理图、转录图、序列图。该计划完成以后的基因研究进入了后基因组时代。     

一种新的乙型肝炎病毒全基因组克隆技术的建立

目的建立一种乙型肝炎病毒(HBV)全基因组扩增及克隆的新方法。方法设计含SalⅠ、NotⅠ酶切位点的引物,用一片段PCR法扩增HBV全基因组,经双酶切后将PCR产物克隆入pBlueScript-(SK-)载体,进行HBV全基因组序列测定。结果用此方法成功获得35例HBV全基因组DNA序列。同时以重组质粒为模板进行敏感性和保真性测定,其敏感性为102个初始模板,核苷酸的人为突变率为1.6bp/kb。结论此方法可用于大规模HBV全基因组扩增和序列分析,为HBV的基础和临床研究提供了一种新方法。     

微粒子酶免疫法测定他可莫司的血药浓度

目的为临床肝移植患者抗移植排斥反应药物的合理应用提供参考。方法采用微粒子酶免疫法(MEIA)对肝移植患者进行他可莫司血药浓度测定,并对结果进行分析。结果为6例肝移植患者检测他可莫司血药浓度77例次,质控结果均在有效范围内。肝移植术后他可莫司全血血药浓度在10-20μg/L范围内的占30.6%。结论为用药安全有效,应对肝移植患者监测FK506血药浓度,实行个体化给药。     

Molecular Characterization of Duck Hepatitis B Virus Isolated from Hubei Brown Ducks

The objective of this study was to characterize the genome structure of duck hepatitis B virus (DHBV) isolated from Hubei brown ducks. The natural carrier rate of DHBV in adult ducks from Hubei area was investigated and the DHBV DNA-positive serum screened out. The complete genome of a DHBV strain was amplified by polymerase chain reaction (PCR) and cloned into T vector and sequenced. The results showed that the carrier rate of DHBV in Hubei brown ducks was 10 %. This strain (GenBank accession number DQ276978) had a genome of 3024 nucleotides with three overlapping open reading frames encoding the surface, core and polymerase proteins respectively. Comparison of the strain with 17 DHBV strains registered in GenBank revealed a homology from 89.3 % to 93.5 % at the nucleotide level. The sequences of the structural and functional domains of these proteins were highly conserved. The strain was found to share more signature amino acids in the polymerase genes with the "Chinese" DHBV strains than those of the "Western" country strains. This finding was also corroborated by a phylogenetic tree analysis. Therefore, the DQ276978 might belong to a subtype of the Chinese DHBV strains.     

Phleboviruses encapsidate their genomes by sequestering RNA bases

Rift Valley fever and Toscana viruses are human pathogens for which no effective therapeutics exist. These and other phleboviruses have segmented negative-sense RNA genomes that are sequestered by a nucleocapsid protein (N) to form ribonucleoprotein (RNP) complexes of irregular, asymmetric structure, previously uncharacterized at high resolution. N binds nonspecifically to single-stranded RNA with nanomolar affinity. Crystal structures of Rift Valley fever virus N-RNA complexes reconstituted with defined RNAs of different length capture tetrameric, pentameric and hexameric N-RNA multimers. All N-N subunit contacts are mediated by a highly flexible α-helical arm. Arm movement gives rise to the three multimers in the crystal structures and also explains the asymmetric architecture of the RNP. Despite the flexible association of subunits, the crystal structures reveal an invariant, monomeric RNP building block, consisting of the core of one N subunit, the arm of a neighboring N, and four RNA nucleotides with the flanking phosphates. Up to three additional RNA nucleotides bind between subunits. The monomeric building block is matched in size to the repeating unit in viral RNP, as visualized by electron microscopy. N sequesters four RNA bases in a narrow hydrophobic binding slot and has polar contacts only with the sugar-phosphate backbone, which faces the solvent. All RNA bases, whether in the binding slot or in the subunit interface, face the protein in a manner that is incompatible with base pairing or with “reading” by the viral polymerase.     

Whole genome sequence to decipher the resistome of Shewanella algae,a multidrug-resistant bacterium responsible for pneumonia,Marseille, France

We characterize and decipher the resistome and the virulence factors of Shewanella algae MARS 14, a multidrug-resistant clinical strain using the whole genome sequencing (WGS) strategy. The bacteria were isolated from the bronchoalveolar lavage of a hospitalized patient in the Timone Hospital in Marseille, France who developed pneumonia after plunging into the Mediterranean Sea. Results: The genome size of S. algae MARS 14 was 5,005,710 bp with 52.8% guanine cytosine content. The resistome includes members of class C and D beta-lactamases and numerous multidrug-efflux pumps. We also found the presence of several hemolysins genes, a complete flagellum system gene cluster and genes responsible for biofilm formation. Moreover, we reported for the first time in a clinical strain of Shewanella spp. the presence of a bacteriocin (marinocin). Conclusion: The WGS analysis of this pathogen provides insight into its virulence factors and resistance to antibiotics.     

Radioprotective effects of black seed (Nigella sativa) oil against hemopoietic damage and immunosuppression in gamma-irradiated rats

Background and aim:?Sixty male Wistar rats, divided into 4 groups, 15 each, were designed as I-control rats, II-rats orally intubated with Nigella sativa oil (1?ml/kg b.wt./day) for 5 days/week, III-whole body gamma irradiated rats with the estimated LD50/30 (4 Gray) and IV-rats daily intubated with Nigella sativa oil then subjected to whole body gamma irradiation, to investigate the radioprotective potential of Nigella crude oil against hemopoietic adverse effects of gamma irradiation.

Results:?Irradiation resulted in significant reduction in hemolysin antibodies titers and delayed type hypersensitivity reaction of irradiated rats, in addition to significant leukopenia and significant decrease in plasma total protein and globulin concentrations and depletion of lymphoid follicles of spleen and thymus gland. Furthermore, there was a significant increase in malondialdehyde concentration with a significant decrease in plasma glutathione peroxidase, catalase and erythrocyte superoxide dismutase activities were recorded. Oral administration of Nigella sativa oil before irradiation considerably normalized all the above-mentioned criteria; and produced significant regeneration in spleen and thymus lymphoid follicles.

Conclusion:?Our results strongly recommend Nigella sativa oil as a promising natural radioprotective agent against immunosuppressive and oxidative effects of ionizing radiation.