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201.
金银花花蕾中的新三萜皂甙   总被引:6,自引:0,他引:6  
从金银花 (LonicerajaponicaThunb .)花蕾中分离得六个化合物 (A—F) ,据化学降解和波谱数据 ,推定了它们的化学结构 ,其中F为一新化合物 ,命名为新常春皂甙F ,其化学结构为 :3-氧 - β -D -葡萄吡喃糖基 (1→ 4 ) - β -D -葡萄吡喃糖基 (1→ 3) -α -L -鼠李吡喃糖基 (1→ 2 )α -L -阿拉伯吡喃糖基 -常春皂甙元 - 2 8-氧 - β -D -葡萄吡喃糖基 (1→ 6 ) -β -D -葡萄吡喃糖基酯 (F)。其它五个化合物的结构分别为 :常春皂甙元 - 3-氧 -α -L -鼠李吡喃糖基 (1→ 2 ) -α -L -阿拉伯吡喃糖甙 (A) ,3-氧 -α -L -鼠李吡喃糖基 (1→ 2 ) -α-L -阿拉伯吡喃糖基 -常春皂甙元 - 2 8-氧 - β -D -吡喃木糖基 (1→ 6 ) - β -D -葡萄吡喃糖基酯 (B) ,3-氧 -α -L -鼠李吡喃糖基 (1→ 2 ) -α -L -阿拉伯吡喃糖基 -常春皂甙元 -2 8-氧 - β -D -葡萄吡喃糖基 (1→ 6 ) - β -D -葡萄吡喃糖基酯 (C) ,3-氧 -α -L -鼠李吡喃糖基 (1→ 2 ) -α -L -阿拉伯吡喃糖基 -常春皂甙元 - 2 8-氧 -α -L -鼠李吡喃糖基 (1→2 ) [β -D -吡喃木糖基 (1→ 6 ) ]- β -D -葡萄吡喃糖基酯 (D) ,3-氧 - β -D -葡萄吡喃糖基 (1→ 3) -α -L -鼠李吡喃糖基 (1→ 2 )α -L -阿拉伯吡喃糖基 -常春皂甙元 - 2 8-氧 - β-D -葡萄吡  相似文献   
202.
广西金线鲃属一新种   总被引:6,自引:0,他引:6  
描记采于广西凌云县泗城镇沙洞地下河中的金线属 1新种 ,以采集地县名命名为凌云金线Sinocyclocheiluslingyunensissp nov 。新种以侧线鳞 71~ 78对 48~ 5 0 ;背鳍最末不分枝鳍条下半部为硬刺 ,后缘有锯齿对纤细柔软 ,光滑无锯齿等特征区别于相近种季氏金线S jiiZhangetDai。  相似文献   
203.
细胞自噬(autophagy)是将细胞内受损、变性或衰老的蛋白质以及细胞器运输到溶酶体内进行消化降解的过程.细胞自噬既是一种广泛存在的正常生理过程,又是细胞对不良环境的一种防御机制,参与多种疾病的病理过程.正常水平的自噬可以保护细胞免受环境刺激的影响,但自噬过度和自噬不足却可能导致疾病的发生.在心脏中,心肌细胞自噬对维持心肌功能具有重要的作用,自噬的异常可能导致各种心肌疾病如溶酶体储积症(Danon disease)等.各种心血管刺激如心肌缺血(ischemia)、再灌注(reperfusion)损伤、慢性缺氧(chronic hypoxia)等均可诱导心肌细胞自噬增强.而这些情况下心肌细胞自噬的作用还不清楚:它是否是一种潜在的细胞存活机制还是导致细胞死亡或疾病发生的病理性机制,或者是同时具有两种作用,目前还没有定论.心脏疾病是心肌功能出现异常时产生的各种病理状态的总称.在多种心脏疾病中,均伴随有心肌细胞自噬的改变,且影响着疾病的发生发展.在心肌肥厚(hypertrophic cardiomyopathy)中,细胞自噬程度降低而加剧心肌肥厚;在心力衰竭(heart failure,HF)中,细胞自噬增强可导致心肌细胞自噬性死亡;而在心肌梗死(myocardial infarction,MI)中,细胞自噬增强可减小梗死面积.但是细胞自噬在心脏疾病中到底扮演着怎样的角色,取决于细胞自噬发生的水平及病理状态.目前越来越多的人开始关注药物与细胞自噬调节之间的联系,且主要集中于抗肿瘤药物及心血管调节药物的研究.另外,有报道维生素类以及雌激素受体拮抗剂他莫西芬对细胞自噬也具有调节作用.研究心肌细胞自噬与心脏疾病的关系,以及药物对细胞自噬的调节,将有利于从自噬的角度探讨心脏疾病的发生发展过程及机制,开发出治疗心脏疾病的药物.  相似文献   
204.
Glucokinase activators represent a promising potential treatment for patients with Type 2 diabetes. Herein, we report the identification and optimization of a series of novel indazole and pyrazolopyridine based activators leading to the identification of 4-(6-(azetidine-1-carbonyl)-5-fluoropyridin-3-yloxy)-2-ethyl-N-(5-methylpyrazin-2-yl)-2H-indazole-6-carboxamide (42) as a potent activator with favorable preclinical pharmacokinetic properties and in vivo efficacy.  相似文献   
205.
目的:利用异丙肾上腺素(ISO)诱导大鼠心肌缺血性损伤模型和心肌细胞损伤模型,并对其进行药物干预,探讨心肌ATP敏感性钾 通道(KATP通道)维持缺血性心肌电平衡的作用与机制。方法:在动物实验中,将雄性SD大鼠,随机分为5组,正常对照组大鼠皮下注射0.9% 氯化钠溶液,其余各组大鼠均皮下注射等量1 g ? L -1 ISO(qd),连续9 d,其间,在第7~9 d,除了正常对照组和模型组外,其他3组大鼠还 分别灌胃给予1.75 g ? L -1 普萘洛尔(PRO)2 mL ? kg -1 ? d -1 、5 g ? L -1 曲美他嗪(VAS)2 mL ? kg -1 ? d -1 或腹腔注射给予5 g ? L -1 二苯基碘(DPI) 1 mL ? kg -1 ? d -1 。在造模期间不同时间点,对各组大鼠进行心电图检查,并制备心肌标本,检测其中KATP通道亚基KIR6.2蛋白表达水平。 在细胞实验中,将H9C2心肌细胞分成对照组(不给药)、ISO组、ISO+ PRO组、ISO+DPI组和ISO+VAS组,后3组细胞均在1 μmol ? L -1 ISO加入前30 min,分别给予2 μmol ? L -1 PRO、10 μmol ? L -1 DPI和10 μmol ? L -1 VAS,且在加入ISO后,与ISO组细胞一样,再孵育1 和24 h,采用实时荧光定量 PCR法测定各组细胞中KATP通道亚基KIR6.2和SUR2A基因表达水平。结果:大鼠实验显示,与正常对照组相比, 模型组大鼠在造模的第3、7 d,心电图参数QTc明显缩短,心率加快(P <0.05),且心肌中KIR6.2蛋白表达明显增多(P <0.01),而造 模9 d后,其QTc明显延长(P <0.01),心率减慢(P <0.05),心肌中KIR6.2蛋白表达显著降低(P <0.01);ISO+ PRO、ISO+DPI 和ISO+VAS各组大鼠在持续3 d分别接受3种药物治疗后,其QTc较模型组明显缩短,心率升高,均趋于恢复正常水平。细胞实验显示, 与对照组相比,ISO组H9C2细胞经ISO孵育1 h后,KIR6.2和SUR2A的mRNA表达显著上调(P <0.05),而在ISO孵育24 h后, KIR6.2和SUR2A的mRNA表达显著下调( P <0.01);与ISO组相比,各给药组细胞经ISO孵育1 h后,KIR6.2和SUR2A的mRNA表 达均有不同程度下调,而在ISO孵育24 h后,KIR6.2和SUR2A的mRNA表达均显著上调(P <0.05或P <0.01)。结论:KATP通道对 维护缺血性心肌电平衡起重要作用。持续性激动β受体、氧化应激或能量供应不足等体内多条途径都会影响KATP通道的表达和功能,而保护 KATP通道功能,对于维持心电平衡,抑制心律失常基质形成,意义重大。  相似文献   
206.
采用正交实验法对假单胞菌进行复合固定化,并对其降酚过程建立动力学方程。研究发现,菌株Pseudomonas stutzeri JFL2012进行复合固定化,最佳固定化条件为w(聚乙烯醇)=10%,w(生物炭)=2.5%,w(包菌量)=0.3%,交联时间4 h。苯酚降解过程符合Haldane底物抑制方程。  相似文献   
207.

Background

Respiratory syncytial virus (RSV) is one of the most frequently observed pathogens during infancy and childhood. However, the corresponding pathogenesis has not been determined to date. We previously demonstrated that IFN-γ plays an important role in RSV pathogenesis, and SARM-TRIF-signaling pathway could regulate the production of IFN-γ. This study is to investigate whether T cells or innate immune cells are the predominant producers of IFN-γ, and further to explore other culprits in addition to IFN-γ in the condition of RSV infection.

Methods

Normal BALB/c mice and nude mice deficient in T cells were infected intranasally with RSV. Leukocytes in bronchoalveolar lavage fluid were counted, lung histopathology was examined, and airway hyperresponsiveness (AHR) was measured by whole-body plethysmography. IFN-γ and MMP-12 were detected by ELISA. MMP408, a selective MMP-12 inhibitor, was given intragastrically. Resveratrol, IFN-γ neutralizing antibody and recombinant murine IFN-γ were administered intraperitoneally. SARM and TRIF protein were semi-quantified by Western blot. siRNA was used to knock-down SARM expression.

Results

RSV induced significant airway inflammation and AHR in both mice; IFN-γ was significantly increased in BALB/c mice but not in nude mice. MMP-12 was dramatically increased in both mice but earlier in nude mice. When MMP-12 was inhibited by MMP408, RSV-induced respiratory symptoms were alleviated. SARM was significantly suppressed while TRIF was significantly enhanced in both mice strains. Following resveratrol administration in nude mice, 1) SARM inhibition was prevented, 2) TRIF and MMP-12 were correspondingly down-regulated and 3) airway disorders were subsequently alleviated. Moreover, when SARM was efficiently knocked down using siRNA, TRIF and MMP-12 were markedly enhanced, and the anti-RSV effects of resveratrol were remarkably abrogated. MMP-12 was significantly increased in the IFN-γ neutralizing antibody-treated BALB/c mice but reduced in the recombinant murine IFN-γ-treated nude mice.

Conclusions

MMP-12 can result in at least part of the airway inflammation and AHR independent of IFN-γ. And SARM-TRIF- signaling pathway is involved in regulating the overproduction of MMP-12. To the best of our knowledge, this study is the first that has examined the effects of SARM on MMP-12 and further highlights the potential to target SARM-TRIF-MMP-12 cascades to treat RSV infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0176-8) contains supplementary material, which is available to authorized users.  相似文献   
208.
209.
Anaerobic ferrous oxidation by heterotrophic denitrifying enriched culture   总被引:1,自引:0,他引:1  
Heterotrophic denitrifying enriched culture (DEC) from a lab-scale high-rate denitrifying reactor was discovered to perform nitrate-dependent anaerobic ferrous oxidation (NAFO). The DEC was systematically investigated to reveal their denitrification activity, their NAFO activity, and the predominant microbial population. The DEC was capable of heterotrophic denitrification with methanol as the electron donor, and autotrophic denitrification with ferrous salt as the electron donor named NAFO. The conversion ratios of ferrous-Fe and nitrate-N were 87.41 and 98.74 %, and the consumption Fe/N ratio was 2.3:1 (mol/mol). The maximum reaction velocity and half saturation constant of Fe were 412.54 mg/(l h) and 8,276.44 mg/l, and the counterparts of N were 20.87 mg/(l h) and 322.58 mg/l, respectively. The predominant bacteria were Hyphomicrobium, Thauera, and Flavobacterium, and the predominant archaea were Methanomethylovorans, Methanohalophilus, and Methanolobus. The discovery of NAFO by heterotrophic DEC is significant for the development of wastewater treatment and the biogeochemical iron cycle and nitrogen cycle.  相似文献   
210.
A sampling system for capturing sturgeon eggs using a D-shaped bottom anchored drift net was used to capture early life stages (ELS) of Chinese sturgeon, Acipenser sinensis , and monitor annual spawning success at Yichang on the Yangtze River, 1996–2004, before and just after the Three Gorges Dam began operation. Captured were 96 875 ELS (early life stages: eggs, yolk-sac larvae = eleuthero embryos, and larvae); most were eggs and only 2477 were yolk-sac larvae. Most ELS were captured in the main river channel and inside the bend at the Yichang spawning reach. Yolk-sac larvae were captured for a maximum of 3 days after hatching began, indicating quick dispersal downstream. The back-calculated day of egg fertilization over the eight years indicated a maximum spawning window of 23 days (20 October–10 November). Spawning in all years was restricted temporally, occurred mostly at night and during one or two spawning periods, each lasting several days. The brief temporal spawning window may reduce egg predation by opportunistic predators by flooding the river bottom with millions of eggs. During 1996–2002, the percentage of fertilized eggs in an annual 20-egg sample was between 63.5 to 94.1%; however, in 2003 the percentage fertilized was only 23.8%. This sudden decline may be related to the altered environmental conditions at Yichang caused by operation of the Three Gorges Dam. Further studies are needed to monitor spawning and changes in egg fertilization in this threatened population.  相似文献   
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