单细胞拉曼技术在病原微生物检测中的研究进展

单细胞拉曼技术是基于拉曼光谱分析原理实现非培养、无标签、快速、高效、低成本揭示物质本质的新方法。近年来,单细胞拉曼技术也开始在病原微生物检测领域崭露头角。本文结合单细胞拉曼技术基本原理这一理论基础,阐述该技术在病原微生物鉴定、药物敏感性检测中的研究进展及最新技术方向,并探讨其在临床实验室应用的可行性,为未来病原微生物检测技术提供新的方向。     

Intragastric Administration of Casein Leads to Nigrostriatal Disease Progressed Accompanied with Persistent Nigrostriatal—Intestinal Inflammation Activited and Intestinal Microbiota—Metabolic Disorders Induced in MPTP Mouse Model of Parkinson’s Disease

Neurochemical Research - Gut microbial dysbiosis and alteration of gut microbiota composition in Parkinson's disease (PD) have been increasingly reported, no recognized therapies are available...     

一起荷斯坦奶牛乳头瘤病诊断及其病毒基因型分析

牛乳头瘤病毒是一种能够引起牛发生皮肤乳头状瘤、纤维素瘤、膀胱和食道癌的DNA病毒,现已在牛群中广泛传播,对牛养殖业造成了重大经济损失.为了诊断甘肃某荷斯坦奶牛场300多头泌乳期奶牛乳头突发疣状物的病因,本研究采用流行病学调查、临床观察、组织病理学、分子生物学检测方法和基因测序技术,对患有疣状物的奶牛进行综合诊断.结果 表明,乳头患疣状物奶牛的其它部位无类似生长物,无发烧、疼痛等异常临床症状,组织病理学HE检测疣状物呈现角化过度和细胞空泡化现象,这与牛乳头瘤病毒感染的组织病理变化相似,并且用PCR方法获得了牛乳头状瘤病毒L1基因,测序比对结果显示为乳头瘤病毒7型基因,核苷酸同源性达98％以上.因此,本次荷斯坦奶牛乳头突发疣状物为乳头瘤病毒7型感染引起的,这是甘肃地区首次发现该基因型乳头瘤病毒,应引起奶牛场与防疫部门的重视.     

ERF转录因子调控生物胁迫反应的研究进展

ERF家族是植物所特有的APETALA2/乙烯响应因子(APETALA2/ethylene-responsive factor,AP2/ERF)转录因子家族的一个主要亚家族,其成员结构特点是仅含有1个58-60个氨基酸组成的AP2/ERF结构域。有关该家族成员的大多数研究集中在与寒、旱等非生物胁迫方面,最近越来越多的研究表明ERF在植物抵御病虫侵害等生物胁迫方面也发挥着重要作用。ERF亚家族成员通过结合下游互作基因启动子区域的GCC box元件,从而激活或抑制这些病程相关基因的表达。同时ERFs参与水杨酸(salicylic acid,SA)、茉莉酸(jasmonic acid,JA)、乙烯(ethylene,ET)及过氧化氢(H2O2)等多种激素的信号途径,通过相互促进/拮抗高效协调体内不同激素抵御病原菌的入侵,提高植物的抗病、抗虫性。本文综述了ERF转录因子的结构功能特点、在不同植物抗生物胁迫中的调控方式,以及其通过协调不同激素信号途径相互作用来提高植物抗病虫的最新研究进展,并对其应用前景进行了展望。     

簇生岐柄菌的超微形态学研究

为揭示网柄细胞状黏菌的超微结构特征,对簇生岐柄菌Cavenderia fasciculata生活史过程中的孢子、黏变形体和柄细胞3种类型的细胞超微结构进行系统观察,并与目前仅知的3种网柄细胞状黏菌的超微结构进行比较。结果表明：簇生岐柄菌C. fasciculata的孢子、黏变形体和柄细胞内均有线粒体结构,随着细胞分化,线粒体内部结构逐渐破坏,并被自噬泡吞噬;孢子表面具有线状纹饰。     

两种网柄细胞状黏菌挥发性成分

采用固相微萃取气相色谱-质谱联用技术,对紫轮柄菌Polysphondylium violaceum和簇生岐柄菌Cavenderia fasciculata子实体的挥发性成分进行分析,从这两种网柄细胞状黏菌中共鉴定出32种挥发性成分,包括烃、醛、吲哚、萜、酮、酯和酚类化合物。其中,紫轮柄菌P. violaceum的挥发性成分有15种化合物,簇生岐柄菌C. fasciculata的挥发性成分有27种化合物,二者共有化合物11种,部分化合物可用于制作香料等,研究结果为网柄细胞状黏菌的进一步应用提供了理论依据。     

抗原抗体复合物型治疗性疫苗(乙克)临床研究中患者血清乙型肝炎病毒表面抗原下降的分析与启示

近年来全球慢性乙型肝炎(chronic hepatitis B,CHB)防治指南提出了“功能性治愈”(functional cure)的概念,即患者经过治疗达到血清乙型肝炎病毒表面抗原(hepatitis B virus surface antigen,HBsAg)消失,但现有抗病毒治疗很难实现这一目标。本研究对既往临床试验中经抗原抗体复合物型治疗性疫苗(乙克)治疗后的CHB患者HBsAg下降情况进行了归纳分析,结果显示,经乙克治疗随访后达到乙型肝炎e抗原(hepatitis B e antigen,HBeAg)血清学转换者的HBsAg下降高达0.95log₁₀IU/mL,显著高于未达到HBeAg血清学转换者的0.32log₁₀IU/mL(P<0.01),而经氢氧化铝佐剂治疗随访后发生HBeAg血清学转换(0.49log₁₀IU/mL)者与未发生HBeAg血清学转换者(0.36log₁₀IU/mL)之间HBsAg下降无统计学差异。乙克组治疗过程中,丙氨酸氨基转移酶(alanine aminotransferase,ALT)骤升(ALT flare)在HBsAg下降>1.0log₁₀IU/mL者中较多见,氢氧化铝组未观察到此现象。回归分析显示,乙克治疗后HBsAg下降的影响因素有患者出现HBeAg血清学转换、感染的HBV为B基因型、治疗过程中ALT出现10倍增高,以及基线血清HBsAg为高水平。结果提示,乙克诱导的特异性免疫对降低CHB患者血清HBsAg水平有一定效果,采用“抗病毒药物治疗＋针对HBsAg的中和性抗体被动免疫＋乙克主动免疫”的“三明治”治疗策略可能会提高“功能性治愈”率。     

Peptide Mimetic of the S100A4 Protein Modulates Peripheral Nerve Regeneration and Attenuates the Progression of Neuropathy in Myelin Protein P0 Null Mice

We recently found that S100A4, a member of the multifunctional S100 protein family, protects neurons in the injured brain and identified two sequence motifs in S100A4 mediating its neurotrophic effect. Synthetic peptides encompassing these motifs stimulated neuritogenesis and survival in vitro and mimicked the S100A4-induced neuroprotection in brain trauma. Here, we investigated a possible function of S100A4 and its mimetics in the pathologies of the peripheral nervous system (PNS). We found that S100A4 was expressed in the injured PNS and that its peptide mimetic (H3) affected the regeneration and survival of myelinated axons. H3 accelerated electrophysiological, behavioral and morphological recovery after sciatic nerve crush while transiently delaying regeneration after sciatic nerve transection and repair. On the basis of the finding that both S100A4 and H3 increased neurite branching in vitro, these effects were attributed to the modulatory effect of H3 on initial axonal sprouting. In contrast to the modest effect of H3 on the time course of regeneration, H3 had a long-term neuroprotective effect in the myelin protein P₀ null mice, a model of dysmyelinating neuropathy (Charcot-Marie-Tooth type 1 disease), where the peptide attenuated the deterioration of nerve conduction, demyelination and axonal loss. From these results, S100A4 mimetics emerge as a possible means to enhance axonal sprouting and survival, especially in the context of demyelinating neuropathies with secondary axonal loss, such as Charcot-Marie-Tooth type 1 disease. Moreover, our data suggest that S100A4 is a neuroprotectant in PNS and that other S100 proteins, sharing high homology in the H3 motif, may have important functions in PNS pathologies.     

Interaction of cyproheptadine hydrochloride with human serum albumin using spectroscopy and molecular modeling methods

The interaction between cyproheptadine hydrochloride (CYP) and human serum albumin (HSA) was investigated by fluorescence spectroscopy, UV–vis absorption spectroscopy, Fourier transform infrared spectroscopy (FT‐IR) and molecular modeling at a physiological pH (7.40). Fluorescence of HSA was quenched remarkably by CYP and the quenching mechanism was considered as static quenching since it formed a complex. The association constants K_a and number of binding sites n were calculated at different temperatures. According to Förster's theory of non‐radiation energy transfer, the distance r between donor (human serum albumin) and acceptor (cyproheptadine hydrochloride) was obtained. The effect of common ions on the binding constant was also investigated. The effect of CYP on the conformation of HSA was analyzed using FT‐IR, synchronous fluorescence spectroscopy and 3D fluorescence spectra. The thermodynamic parameters ΔH and ΔS were calculated to be ?14.37 kJ mol^?1 and 38.03 J mol^?1 K^?1, respectively, which suggested that hydrophobic forces played a major role in stabilizing the HSA‐CYP complex. In addition, examination of molecular modeling indicated that CYP could bind to site I of HSA and that hydrophobic interaction was the major acting force, which was in agreement with binding mode studies. Copyright © 2012 John Wiley & Sons, Ltd.     

Combined multispectroscopic and molecular docking investigation on the interaction between strictosamide and human serum albumin

The interaction between strictosamide (STM) and human serum albumin (HSA) was investigated by fluorescence spectroscopy, synchronous fluorescence spectroscopy, three‐dimensional fluorescence spectroscopy, ultraviolet‐visible absorption spectroscopy, circular dichroism spectroscopy and molecular modeling under physiological pH 7.4. STM effectively quenched the intrinsic fluorescence of HSA via static quenching. The binding site number n and apparent binding constant K_a were determined at different temperatures by fluorescence quenching. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) for the reaction were calculated as ?3.01 kJ/mol and 77.75 J/mol per K, respectively, which suggested that the hydrophobic force played major roles in stabilizing the HSA–STM complex. The distance r between donor and acceptor was obtained to be 4.10 nm according to Förster's theory. After the addition of STM, the synchronous fluorescence and three‐dimensional fluorescence spectral results showed that the hydrophobicity of amino acid residues increased and the circular dichroism spectral results showed that the α‐helix content of HSA decreased (from 61.48% to 57.73%). These revealed that the microenvironment and conformation of HSA were changed in the binding reaction. Furthermore, the study of molecular modeling indicated that STM could bind to site I of HSA and the hydrophobic interaction was the major acting force, which was in agreement with the binding mode study. Copyright © 2013 John Wiley & Sons, Ltd.