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31.
Antiviral flavonoids from the root bark of Morus alba L 总被引:7,自引:0,他引:7
A prenylated flavonoid, moralbanone, along with seven known compounds kuwanon S, mulberroside C, cyclomorusin, eudraflavone B hydroperoxide, oxydihydromorusin, leachianone G and alpha-acetyl-amyrin were isolated from the root bark of Morus alba L. Leachianone G showed potent antiviral activity (IC(50) = 1.6 microg/ml), whereas mulberroside C showed weak activity (IC(50) = 75.4 microg/ml) against herpes simplex type 1 virus (HSV-1). Their structures were elucidated by spectroscopic methods. 相似文献
32.
目的探讨氟康唑3日间隔疗法治疗念珠菌性外阴、阴道炎的临床疗效。方法110例患者随机分为两组.治疗组60例采用氟康唑3日间隔疗法(第1日服药150mg后.第4、7日各再服1次),对照组50例1次单剂量口服氟康唑150mg。结果治疗组和对照组有效率分别为86.67%、72.00%.差异有显著性(χ^2=9.46,P〈0.05).结论氟康唑3日间隔疗法治疗念珠菌性外阴、阴道炎疗效好。毒副作用小,安全性高。 相似文献
33.
五唇兰雌配子体发育和胚胎发生的研究 总被引:11,自引:2,他引:11
五唇兰的胚珠倒生型,具薄珠心,两层珠被。胚囊发育为双孢子葱型,成熟胚囊8核。从传粉到受精约50d,正常双受精。胚具5-6细胞的胚柄,种子成熟时胚柄及胚乳核消失,成熟种子只具单层细胞的种皮和一个未分化的珠珠形胚。 相似文献
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36.
Engineering of Plasmin-Resistant Forms of Streptokinase and Their Production in Bacillus subtilis: Streptokinase with Longer Functional Half-Life 下载免费PDF全文
The short in vivo half-life of streptokinase limits its efficacy as an efficient blood clot-dissolving agent. During the clot-dissolving process, streptokinase is processed to smaller intermediates by plasmin. Two of the major processing sites are Lys59 and Lys386. We engineered two versions of streptokinase with either one of the lysine residues changed to glutamine and a third version with both mutations. These mutant streptokinase proteins (muteins) were produced by secretion with the protease-deficient Bacillus subtilis WB600 as the host. The purified muteins retained comparable kinetics parameters in plasminogen activation and showed different degrees of resistance to plasmin depending on the nature of the mutation. Muteins with double mutations had half-lives that were extended 21-fold when assayed in a 1:1 molar ratio with plasminogen in vitro and showed better plasminogen activation activity with time in the radial caseinolysis assay. This study indicates that plasmin-mediated processing leads to the inactivation of streptokinase and is not required to convert streptokinase to its active form. Plasmin-resistant forms of streptokinase can be engineered without affecting their activity, and blockage of the N-terminal cleavage site is essential to generate engineered streptokinase with a longer in vitro functional half-life. 相似文献
37.
Detection of the synergetic effects between variants, such as single-nucleotide polymorphisms (SNPs), is crucial for understanding the genetic characters of complex diseases. Here, we proposed a two-step approach to detect differentially inherited SNP modules (synergetic SNP units) from a SNP network. First, SNP-SNP interactions are identified based on prior biological knowledge, such as their adjacency on the chromosome or degree of relatedness between the functional relationships of their genes. These interactions form SNP networks. Second, disease-risk SNP modules (or sub-networks) are prioritised by their differentially inherited properties in IBD (Identity by Descent) profiles of affected and unaffected sibpairs. The search process is driven by the disease information and follows the structure of a SNP network. Simulation studies have indicated that this approach achieves high accuracy and a low false-positive rate in the identification of known disease-susceptible SNPs. Applying this method to an alcoholism dataset, we found that flexible patterns of susceptible SNP combinations do play a role in complex diseases, and some known genes were detected through these risk SNP modules. One example is GRM7, a known alcoholism gene successfully detected by a SNP module comprised of two SNPs, but neither of the two SNPs was significantly associated with the disease in single-locus analysis. These identified genes are also enriched in some pathways associated with alcoholism, including the calcium signalling pathway, axon guidance and neuroactive ligand-receptor interaction. The integration of network biology and genetic analysis provides putative functional bridges between genetic variants and candidate genes or pathways, thereby providing new insight into the aetiology of complex diseases. 相似文献
38.
Jang do S Lee HJ Lee B Hong BH Cha HJ Yoon J Lim K Yoon YJ Kim J Ree M Lee HC Choi KY 《FEBS letters》2006,580(17):4166-4171
Failure to detect the intermediate in spite of its existence often leads to the conclusion that two-state transition in the unfolding process of the protein can be justified. In contrast to the previous equilibrium unfolding experiment fitted to a two-state model by circular dichroism and fluorescence spectroscopies, an equilibrium unfolding intermediate of a dimeric ketosteroid isomerase (KSI) could be detected by small angle X-ray scattering (SAXS) and analytical ultracentrifugation. The sizes of KSI were determined to be 18.7A in 0M urea, 17.3A in 5.2M urea, and 25.1A in 7M urea by SAXS. The size of KSI in 5.2M urea was significantly decreased compared with those in 0M and 7M urea, suggesting the existence of a compact intermediate. Sedimentation velocity as obtained by ultracentrifugation confirmed that KSI in 5.2M urea is distinctly different from native and fully-unfolded forms. The sizes measured by pulse field gradient nuclear magnetic resonance (NMR) spectroscopy were consistent with those obtained by SAXS. Discrepancy of equilibrium unfolding studies between size measurement methods and optical spectroscopies might be due to the failure in detecting the intermediate by optical spectroscopic methods. Further characterization of the intermediate using (1)H NMR spectroscopy and Kratky plot supported the existence of a partially-folded form of KSI which is distinct from those of native and fully-unfolded KSIs. Taken together, our results suggest that the formation of a compact intermediate should precede the association of monomers prior to the dimerization process during the folding of KSI. 相似文献
39.
不同培养条件对猪卵母细胞IVM、IVF的影响 总被引:3,自引:0,他引:3
通过优化猪卵母细胞体外成熟、体外受精和胚胎体外发育体系,以进一步提高体外胚胎的生产效率和质量.研究了激素存在时间、不同激素和不同血清对猪卵母细胞体外成熟的影响;共培养体系、精卵作用时间、去除卵丘细胞的方法对猪体外受精及早期胚胎发育的影响.猪卵母细胞IVM培养48h,前24h内加入PMSG、hCG,后24h将其去除,卵母细胞总成熟率为79.54%;培养液添加15?S或15%NCS,卵母细胞成熟率分别为79.48%和74.81%;PMSG、HCG和E2配合使用后卵母细胞成熟率为81.42%.在IVF前用吹打法获得的卵裂率、桑椹胚率分别为37.89%和8.54%,精卵共孵育6h或8h的卵裂率(40.52%,37.24%)、桑椹胚率(8.42%,7.85%),以及用输卵管上皮细胞共培养所获得的卵裂率(40.84%)、桑椹胚率(9.53%)均显著高于其它各组. 相似文献
40.
Ye Xia Eliana Greissworth Curtis Mucci Mark A. Williams Seth De Bolt 《Global Change Biology Bioenergy》2013,5(6):674-682
Switchgrass (Panicum virgatum L.) is a perennial warm season grass that is native to the plains of North America and is widely grown as a forage, bioenergy or groundcover crop. Despite its importance, a bottleneck in switchgrass production is poor seedling vigor, which as a perennial crop represents an important time for management. Herein, data identify a suite of culturable bacterial microflora extracted from switchgrass, and show their capability to influence host plant growth and development. A total of 307 bacterial isolates were cultured and isolated from surface sterilized switchgrass biomass and sequence identified into 76 strains (subspecies classification), 36 species and 5 phyla. Approximately 58% of bacterial strains, when reintroduced into surface‐sterilized switchgrass seeds, were documented to increase lamina length (cm from base to tip after 60 days growth) relative to uninoculated controls. Ecologically, Phylum Firmicutes was the most abundant bacterial classification and encompassed 75% of all isolates. Although the culturable bacterial community studies herein represent an unknown and assumedly minor proportion of the total microbiome, by focusing on culturable bacteria, we delineate functional feedback between the presence of isolated bacteria and switchgrass seedling growth. 相似文献