Potential clinical treatment for Ebola pandemic

<正>West African countries are currently suffering the most severe pandemic of Ebola virus disease ever recorded,with4269 human cases and 2288 deaths(through 6 September2014),and the number of cases in the current outbreak exceeds the number from all previous outbreaks combined.Ebola virus disease was first described in 1976 originating from the Ebola River in the Democratic Republic of the Congo.Five Ebola viruses have been reported to cause     

Effects of radix polygoni multiflori components on tyrosinase activity and melanogenesis

Radix Polygoni multiflori is a herb used effectively to prevent graying and treat skin depigmentation diseases in traditional Chinese medicine but its active ingredients have not been discovered yet. In this investigation, we tested six compounds isolated from Radix Polygoni multiflori, to discover the active component on melanogenesis. Three experiments were performed in the present investigation: mushroom tyrosinase activity, melanin content B16 cell proliferation assay. Among all the six components tested, THSG showed the most potent effects on tyrosinase activation and melanogenesis; it was shown to be a potent tyrosinase activator and a melanogenesis stimulator in this study. On the other hand, we found that gallic acid significantly inhibited tyrosinase and, in addition, anthraquinones were cytotoxic to melanoma cells. They were both harmful to melanogenesis. Therefore, we propose that THSG acts as the active ingredient of Radix Polygoni multiflori on melanogenesis.     

Plasmodium falciparum: Development and validation of a measure of intraerythrocytic growth using SYBR Green I in a flow cytometer

Reliable analytical techniques to test growth-promoting and antimalarial efficacy on plasmodia are very important. Flow cytometry (FCM) offers the possibility to study developmental stages of intraerythrocytic growth of malaria parasites using nucleic acid staining. To analyze the growth of Plasmodium falciparum SYBR Green I was introduced as an intercalating dye with FCM for the 488 nm line of an argon laser. Procedures employing FCM, including fixatives, dye concentrations, dilution buffer, and staining period, were optimized to simplify the method. FCM as described here allows parasitemia and parasites of different stages to be quantified according to the DNA content. The proportion of parasitized erythrocytes estimated by FCM and the Giemsa method agreed with determination by parasite lactate dehydrogenase. The protocol was extended to merozoite counting as a sensitive assay of growth inhibition of the parasite.     

菌株S.tz的抗菌活性及其生物学研究

从沈阳天柱山土壤中分离到一种链霉菌S．tz,试验表明它所产生的水溶性抗生素不但对植物病毒有较好的防效．而且具有很强的抗真菌活性,对甜瓜枯萎病菌．番茄叶霉病菌,烟草赤星病菌等多种植物病原真菌表现强烈的抑菌效果,该菌株的形态特征．培养特征、生理生化特性等种的鉴定特征与不吸水链霉菌(Streptomyces ahygroscopicus)相似,初步鉴定该菌株是不吸水链霉菌的一个新的变种。     

胡桃楸提取液对肿瘤细胞细胞周期的影响

目的考察胡桃楸提取液对Hela和K562细胞周期的影响。方法用流式细胞仪分析胡桃楸提取液对Hela、K562细胞细胞周期的影响。结果胡桃楸提取物体外作用于Hela细胞可引起细胞周期在S期的停滞,这种效果随药物浓度和作用时间的增加而增加,胡桃楸提取物体外作用于K562细胞,可引起细胞周期在G1期的停滞,随药物浓度的增加而增加。结论胡桃楸提取液对Hela细胞的生长抑制作用可能通过S期阻滞实现,对K562细胞抑制作用可能通过G1期阻滞实现。     

酶解骨胶原多肽的抗氧化特性研究

本文主要研究了酶解法制备的骨胶原多肽的总抗氧化能力、羟自由基清除作用和抑制超氧阴离子自由基的能力.通过与谷胱甘肽(GSH)的比较发现,溶液浓度在1130～150 mg/mL时,该骨胶原多肽的总抗氧化能力为GSH的71.92%.溶液浓度在2.5～20 mg/mL时,该多肽羟自由基清除作用为谷胱甘肽的1.36倍.溶液浓度为10～150 mg/mL时,多肽抑制超氧阴离子自由基的能力低于谷胱甘肽.     

双链RNA对薇甘菊根基因MmEXPA4的靶向抑制

【目的】结合薇甘菊较强的节节生根能力的生物学特性,研发利用RNAi技术抑制薇甘菊根系生长基因表达的生物防治技术,为进一步开发薇甘菊靶向防控技术奠定基础。【方法】利用同源比对方法,鉴定出调控薇甘菊根系发育的关键基因(MmEXPA4),体外合成该基因的双链RNA (dsMmEXPA4),利用dsMmEXPA4注射薇甘菊根部,研究其对薇甘菊根系生长的作用。【结果】与对照组相比,dsMmEXPA4处理30 d后,所有不定根的数量、鲜重和最长不定根的长度均显著降低。qRT-PCR检测结果表明,在dsMmEXPA4处理后第4和第5天,MmEXPA4基因的表达量显著下调,沉默效率分别为43.96%和52.11%。此外,通过Fluorescent Stereo Microscope Leica M165 FC发现,被荧光标记的dsMmEXPA4能在根系中测检到较强的绿色荧光信号。【结论】MmEXPA4基因可作为抑制薇甘菊根系发育及快速生长的潜在靶点,为利用RNA干扰技术生物防治薇甘菊提供理论基础。     

橄榄果实中PPO和POD活性抑制研究

本文研究温度和几种抑制剂对橄榄果实多酚氧化酶(PPO)和过氧化物酶(POD)活性的影响。结果表明,橄榄果实PPO活性最强的温度为27℃,POD活性最强的温度为45℃;低温对PPO活性的抑制较POD显著;抗坏血酸和亚硫酸钠可有效地抑制PPO活性,而抗坏血酸和氯化镁则对POD活性有明显的抑制作用。