Diallyl disulfide from garlic oil inhibits Pseudomonas aeruginosa virulence factors by inactivating key quorum sensing genes

Applied Microbiology and Biotechnology - Garlic oil can disrupt the quorum sensing (QS) pathways of the opportunistic pathogen Pseudomonas aeruginosa; however, the underlying mechanisms for this...     

四川地区幼儿和学龄前儿童的鼻部测量

本文报告１１１６例四川地区幼儿和学龄前儿童（２－７岁）鼻部９项指标的测量均数,性差及年龄发育特点。性差：仅鼻凹鼻底距４－６．５岁等少数指标部分年龄段男女性间出现显著性划异（男＞女）。此外各项指标的绝大多数年龄段男女性间无显著性差异。年龄发育：９项测量指标中７项的生长曲线随年产长而上升,数值随年龄增大,并有１－２个发育高峰;提示鼻部发育具有阶段性;２项指标的曲线随年龄增长变化较小。４项指标男女性的曲     

Asymmetric synthesis of carbocyclic pyrimidine nucleosides via pi-allylpalladium complex

Racemic and enantiomerically pure carbocyclic pyrimidine nucleosides were synthesized efficiently by a convergent approach using Trost nucleophilic addition of pi-allylpalladium complexes.     

植物非生物胁迫相关转录因子研究方法

转录因子是一类能够与启动子区域顺式作用元件特异性结合的蛋白质,是一大类转录调控因子,也是植物中最大的基因家族之一。转录因子可以调节众多下游基因的表达,对植物的生长发育、形态建成、激素调节,以及抵抗多种生物和非生物胁迫具有重要作用。结合近年来转录因子的研究进展,归纳总结了植物非生物胁迫相关转录因子研究的主要策略和方法,包括转录因子结构域、亚细胞定位、转录激活作用、转录因子复合体以及转录因子功能的研究,为植物转录因子的相关研究提供理论和方法的参考。     

菘蓝CYP83B1基因的克隆与表达分析

对菘蓝（Isatis indigotica Fort.）CYP83B1基因进行了克隆与表达模式分析。结果显示,IiCYP83B1基因全长为1652 bp,包含2个外显子和1个内含子;cDNA全长为1500 bp,编码499个氨基酸。IiCYP83B1编码的蛋白没有跨膜结构域和信号肽,主要定位于内质网膜,属于亲水性蛋白,二级结构主要由无规则卷曲螺旋和α-螺旋组成,与萝卜（Raphanus sativus Linn.）、欧洲油菜（Brassica napus L.）、甘蓝（Brassica oleracea L.）和芜菁（Brassica rapa L.）等植物的CYP83B1蛋白具有较高的同源性。qRT-PCR分析结果表明,IiCYP83B1基因在菘蓝的根、茎、叶、花和果中均有表达,且以叶中的表达量最高;在幼苗期、生长期和花期稳定表达且均显著高于萌芽期;茉莉酸甲酯（methyl jasmonate,MeJA）和葡萄糖（glucose,Glu）能够显著促进该基因的表达,而低温（4℃）和水杨酸（salicylic acid,SA）处理对其表达具有一定的抑制效应。本研究结果可为进一步探讨IiCYP83B1基因的功能提供参考。     

Recombinant expression of alpha-bungarotoxin in Pichia pastoris facilitates identification of mutant toxins engineered to recognize neuronal nicotinic acetylcholine receptors

A snake venom-derived alpha-neurotoxin, alpha-bungarotoxin (alphaBgtx), is the classic competitive antagonist of nicotinic acetylcholine receptors (nAChRs). The very high specificity and essentially irreversible binding of alphaBgtx to various nAChRs make alphaBgtx the prime candidate for studying the molecular determinants of specificity for nAChR-ligand interactions. To facilitate site-directed mutagenesis of alphaBgtx for functional analysis, we have developed a recombinant expression system for alphaBgtx using the methylotropic yeast Pichia pastoris. A synthetic gene coding for alphaBgtx was subcloned into an expression vector that directs secretion of the recombinant alphaBgtx (rBgtx) when stably integrated into the yeast genome. Expression of rBgtx was induced by growth of yeast cultures with methanol as the sole carbon source. The activity of the rBgtx in the cell-free medium was measured by competition with 1251-Bgtx for binding to Torpedo nAChR-enriched membranes. The rBgtx, purified to homogeneity by standard HPLC, has the correct predicted amino terminal sequence and molecular mass. Its circular dichroism spectrum is very similar to that of authentic venom-derived alphaBgtx, and the biological activity of the rBgtx is identical to that of authentic alphaBgtx. We have used the Pichia expression system to study a double point mutation of alphaBgtx, rBgtx-K38P/L42Q, that has a high affinity for alpha3beta2 neuronal nAChRs. This is the first demonstration of engineering an alpha-neurotoxin to recognize non-alpha7 neuronal nicotinic receptors.     

Naringin in Ganshuang Granule suppresses activation of hepatic stellate cells for anti‐fibrosis effect by inhibition of mammalian target of rapamycin

A previous study has demonstrated that Ganshuang granule (GSG) plays an anti‐fibrotic role partially by deactivation of hepatic stellate cells (HSCs). In HSCs activation, mammalian target of rapamycin (mTOR)‐autophagy plays an important role. We attempted to investigate the role of mTOR‐autophagy in anti‐fibrotic effect of GSG. The cirrhotic mouse model was prepared to demonstrate the anti‐fibrosis effect of GSG. High performance liquid chromatography (HPLC) analyses were used to identify the active component of GSG. The primary mouse HSCs were isolated and naringin was added into activated HSCs to observe its anti‐fibrotic effect. 3‐methyladenine (3‐MA) and Insulin‐like growth factor‐1 (IGF‐1) was added, respectively, into fully activated HSCs to explore the role of autophagy and mTOR. GSG played an anti‐fibrotic role through deactivation of HSCs in cirrhotic mouse model. The concentration of naringin was highest in GSG by HPLC analyses and naringin markedly suppressed HSCs activation in vitro, which suggested that naringin was the main active component of GSG. The deactivation of HSCs caused by naringin was not because of the autophagic activation but mTOR inhibition, which was supported by the following evidence: first, naringin induced autophagic activation, but when autophagy was blocked by 3‐MA, deactivation of HSCs was not attenuated or reversed. Second, naringin inhibited mTOR pathway, meanwhile when mTOR was activated by IGF‐1, deactivation of HSCs was reversed. In conclusion, we have demonstrated naringin in GSG suppressed activation of HSCs for anti‐fibrosis effect by inhibition of mTOR, indicating a potential therapeutic application for liver cirrhosis.     

Gene microarray analysis of expression profiles in Suberoyllanilide hyroxamic acid-treated Dendritic cells

Objective

The purpose of this study is to provide a further theoretical basis for the role of Suberoyllanilide hyroxamic acid (SAHA) affect on Dendritic cells (DCs).

泛素样蛋白ISG15抗病毒机制研究进展

ISG15(Interferon stimulated gene 15,ISG15)蛋白是由干扰素诱导产生的一种泛素样蛋白分子,分子量大小约为15kD。ISG15同泛素分子相类似可以被共价结合于其他蛋白分子上,这种现象称为ISG化(ISGylation)现象。ISG化系统包括ISG15、UBE1L、UBCH8和HERC5四类蛋白分子,协同完成ISG化过程。ISG15及ISG化系统在抗病毒反应中具有重要作用。近几年对于ISG15的抗病毒作用和机制的研究已经有了很大的突破,ISG15的抗病毒作用也越来越受到人们重视,了解清楚ISG15抗病毒机制对于研制新的抗病毒药物及提出新的抗病毒策略具有重要意义。本文对ISG15在不同种病毒中的抗病毒机制研究进展进行了简要综述。