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1.
Background: CDK4/6 (Cyclin-dependent kinases 4/6) are the key promoters of cell cycle transition from G1 phase to S phase. Thus, selective inhibition of CDK4/6 is a promising cancer treatment. Methods: A total of 52,765 marine natural products were screened for CDK4/6. To screen out better natural compounds, pharmacophore models were first generated, then the absorption, distribution, metabolism, elimination, and toxicity (ADMET) were tested, followed by molecular docking. Finally, molecular dynamics simulation was carried out to verify the binding characteristics of the selected compounds. Results: Eighty-seven marine small molecules were screened based on the pharmacophore model. Then, compounds 41369 and 50843 were selected according to the ADMET and molecular docking score for further kinetic simulation evaluation. Finally, through molecular dynamics analysis, it was confirmed that compound 50843 maintained a stable conformation with the target protein, so it has the opportunity to become an inhibitor of CDK4/6. Conclusion: Through structure-based pharmacophore modeling, ADMET, the molecular docking method and molecular dynamics (MD) simulation, marine natural compound 50843 was proposed as a promising marine inhibitor of CDK4/6. 相似文献
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齿兰环斑病毒与建兰花叶病毒分子检测研究 总被引:2,自引:0,他引:2
齿兰环斑病毒(Odontoglossum ringspot virus,ORSV)与建兰花叶病毒(Cymbidium mosaic virus, CyMV)是严重危害兰科植物的两种主要病毒。本研究根据病毒外壳蛋白基因设计特异性引物,应用ELISA、普通RT-PCR、巢式RT-PCR和免疫捕获RT-PCR4种方法进行了检测研究与比较。结果表明:普通RT-PCR与ELISA方法检测灵敏度相当;巢式RT-PCR检测灵敏度要比普通RT-PCR与ELISA方法高出104倍以上;免疫捕获RT-PCR检测灵敏度介于普通RT-PCR和巢式RT-PCR之间。采用巢式RT-PCR方法对我国台湾进境的蝴蝶兰植株样本检测,1号样本出现与阳性对照一致的特异条带。双向测序分析,扩增产物序列与ORSV外壳蛋白基因具有100%的同源性,表明1号蝴蝶兰样本携带ORSV。 相似文献
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Wang Y Bai Y Qu Q Xu J Chen Y Zhong Z Qiu Y Wang T Du X Wang Z Yu S Fu S Yuan J Zhen Q Yu Y Chen Z Huang L 《Veterinary microbiology》2011,151(3-4):354-362
Brucellosis brings great economic burdens for developing countries. Live attenuated vaccines are the most efficient means for prevention and control of animal Brucellosis. However, the difficulties of differentiating of infection from vaccine immunization, which is essential for eradication programs, limit their applications. Therefore, the development of a vaccine that could differentiate infection from immunization will overcome the limitations and get extensive application. VjbR is a quorum sensing regulator involving in Brucella's intracellular survival. The vjbR∷Tn5 mutants have been proven effective against wild type strain challenge, implying its possibility of use in vaccine candidate development. To further evaluate this candidate gene, in the present study, the antigenicity of purified recombinant VjbR protein was analyzed. Antibodies to Brucella melitensis VjbR could be detected in sera from patients and animals with brucellosis but not in control ones, implying the potential use of this protein as a diagnostic antigen. Then a vjbR mutant of B. melitensis 16M was constructed by replacing the vjbR with kanamycin gene. The mutant showed reduced survival in macrophage and mice. Vaccination of BALB/c mice with 16MΔvjbR conferred significant protective immunity against B. melitensis strain 16M challenges, being equivalent to which induced by the license vaccine Rev.1. The vjbR deletion mutant elicited an anti-Brucella-specific immunoglobulin G response and induced the secretion of gamma interferon and interleukin-10. The most importance is that, the use of vjbR mutants as vaccines in association with diagnostic tests based on the VjbR antigen would allow the serological differentiation between infected and vaccinated animals. These results suggest that 16MΔvjbR is an ideal live attenuated vaccine candidate against B. melitensis and deserves further evaluation for vaccine development. 相似文献
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7~10岁健康猕猴15只,随机分为Ⅰ、Ⅱ、Ⅲ组,每组5只,分别按照100、125、150mg/kg的剂量一次性静脉注射链脲菌素,连续观察血糖、血浆C肽和胰岛素浓度的动态变化,观察期15周.结果:与注射链脲菌素前比较,注射后1周,Ⅰ组猕猴血糖浓度明显升高,血浆C肽和胰岛素浓度显著下降(P<0.01),随后趋于正常水平,而Ⅱ、Ⅲ组猕猴血糖浓度明显升高并在随后的时间内持续维持在高水平,血浆C肽和胰岛素浓度持续维持在低水平(P<0.001),Ⅲ组动物至15周全部死亡.结论:按照125mg/kg的剂量一次性给猕猴静脉注射链脲菌素,可成功复制1型糖尿病动物模型,其维持高血糖和低胰岛素及C肽浓度至少15周. 相似文献
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病死畜禽处理的现状及其无害化处理技术 总被引:1,自引:0,他引:1
近年来出现的"黄浦江漂猪事件"和"江西高安病死猪事件",引发了人们对病死畜禽无害化处理问题的担忧。病死畜禽的无害化处理还存在养殖者不受重视、政府部门监管不到位、补贴政策落实不到位和处理技术落后等问题。本文分析了当前病死畜禽处理的现状,阐述了五种病死畜禽的无害化处理技术,并提出了4点对策建议。 相似文献