Science Letters： A synthetic Toll-like receptor 2 ligand decreases allergic immune responses in a mouse rhinitis model sensitized to mite allergen

It has been proposed that activation of Toll-like receptors (TLRs) plays crucial roles in the polarization of adaptive immune responses. A synthetic Toll-like receptor 2 (TLR2) ligand, Pam3CSK4, has been reported to modulate the balance of Thl/Tn2 responses. We evaluated the modulation effect of Pam3CSK4 on allergic immune response in a mouse rhinitis model sensitized to house dust mite allergen (HDM). Mice were sensitized and challenged with Dermatophagoides farinae allergen (Der f), and then the allergic mice were treated by Pam3CSK4. Nasal allergic symptoms and eosinophils were scored. Der f-specific cytokine responses were examined in the splenocytes and bronchoalveolar lavage fluid (BALF). Serum level of total IgE was also detected. After establishing a mouse allergic rhinitis model with HDM, we have showed that Pam3CSK4 treatment not only ameliorated the nasal allergic symptoms remarkably but also decreased the eosinophils and total inflammation cells in BALF significantly. Analysis of cytokine profile found that' IFN-γ released from either BALF or stimulated splenocytes increased markedly in Pam3CSK4-treated mice, while IL-13 decreased significantly. Moreover, serum level of total IgE was significantly lower in Pam3CSK4-treated mice than in the untreated. Thus, in an allergic rhinitis mouse model developed with HDM, Pam3CSK4 was shown to exhibit an antiallergic effect, indicating its potential application in allergic diseases.     

Science Letters: A synthetic Toll-like receptor 2 ligand decreases allergic immune responses in a mouse rhinitis model sensitized to mite allergen

It has been proposed that activation of Toll-like receptors (TLRs) plays crucial roles in the polarization of adaptive immune responses. A synthetic Toll-like receptor 2 (TLR2) ligand, Pam3CSK4, has been reported to modulate the balance of Thl/Tn2 responses. We evaluated the modulation effect of Pam3CSK4 on allergic immune response in a mouse rhinitis model sensitized to house dust mite allergen (HDM). Mice were sensitized and challenged with Dermatophagoides farinae allergen (Der f), and then the allergic mice were treated by Pam3CSK4. Nasal allergic symptoms and eosinophils were scored. Der f-specific cytokine responses were examined in the splenocytes and bronchoalveolar lavage fluid (BALF). Serum level of total IgE was also detected. After establishing a mouse allergic rhinitis model with HDM, we have showed that Pam3CSK4 treatment not only ameliorated the nasal allergic symptoms remarkably but also decreased the eosinophils and total inflammation cells in BALF significantly. Analysis of cytokine profile found that' IFN-γ released from either BALF or stimulated splenocytes increased markedly in Pam3CSK4-treated mice, while IL-13 decreased significantly. Moreover, serum level of total IgE was significantly lower in Pam3CSK4-treated mice than in the untreated. Thus, in an allergic rhinitis mouse model developed with HDM, Pam3CSK4 was shown to exhibit an antiallergic effect, indicating its potential application in allergic diseases.     

Differences in dinucleotide frequencies of thermophilic genes encoding water soluble and membrane proteins

The occurrence frequencies of the dinucleotides of genes of three thermophilic and three mesophilic species from both archaea and eubacteria were investigated in this study. The genes encoding water soluble proteins were rich in the dinucleotides of purine dimers, whereas the genes encoding membrane proteins were rich in pyrimidine dimers. The dinucleotides of purine dimers are the counterparts of pyrimidine dimers in a double-stranded DNA. The purine/pyrimidine dimers were favored in the thermophiles but not in the mesophiles, based on comparisons of observed and expected frequencies. This finding is in agreement with our previous study which showed that purine/pyrimidine dimers are positive factors that increase the thermal stability of DNA. The dinucleotides AA, AG, and GA are components of the codons of charged residues of Glu, Asp, Lys, and Arg, and the dinucleotides TT, CT, and TC are components of the codons of hydrophobic residues of Leu, Ile, and Phe. This is consistent with the suitabilities of the different amino acid residues for water soluble and membrane proteins. Our analysis provides a picture of how thermophilic species produce water soluble and membrane proteins with distinctive characters: the genes encoding water soluble proteins use DNA sequences rich in purine dimers, and the genes encoding membrane proteins use DNA sequences rich in pyrimidine dimers on the opposite strand.     

动词拷贝句句式构造和句式意义的互动关系

本文通过基于论元结构和配位方式的互动关系的派生分析,对动词拷贝句(重动句)的句式构造和句式意义的互动关系做出了结构化、一致化的分析,并就此对动词拷贝句的语义/功能特点这些学界有较大争议的问题提出新的分析。文章主张,研究特定句式的形式和意义及其关系,应该将该句式放到相关句式群中去考察。本文在研究特殊句式的形义关系时,尝试走一条基于互动—派生分析模式的精致还原主义之路。     

质子交换膜燃料电池水管理的建模和分析

质子交换膜燃料电池的水管理是影响其性能的重要因素之一。电池水管理的目的就是要实现尽可能高的膜的水合程度,降低膜的阻抗。为了更好实现以上目标,文中建立了电池水传输模型,基于模型利用工程逼近分析方法,分析了阴阳极湿度、反应气体流量对膜的水含量和阴阳极水分压的影响。仿真结果通过与其他模型相比较,取得了一致的结果,因此也证明了该模型的有效和实用性。基于以上的分析结果为建立简化的膜水含量控制模型和实现水管理的控制目标奠定基础。     

Determination of the genus-specific antigens in outer membrane proteins from the strains of Leptospira interrogans and Leptospira biflexa with different virulence

Objective: To determine the existence of genus-specific antigens in outer membrane proteins (OMPs) of leptospira with different virulence. Methods: Microscope agglutination test (MAT) was applied to detect the agglutination between commercial rabbit antiserum against leptospiral genus-specific TR/Patoc I antigen and 17 strains of Leptospira interrongans belonging to 15 serogroups and 2 strains of Leptospira biflexa belonging to 2 serogroups. The outer envelopes (OEs) of L.interrogans serogroup Icterohaemorrhagiae serovar lai strain lai (56601) with strong virulence and serogroup Pomona serovar pomona strain Luo (56608) with low virulence, and L.biflexa serogroup Semaranga serovar patoc strain Patoc I without virulence were prepared by using the method reported in Auran et al.(1972). OMPs in the OEs were obtained by treatment with sodium deoxycholate. SDS-PAGE and western blot were used for analyzing the features of the OMPs on electrophoretic pattern and the immunoreactivity to the antiserum against TR/Patoc I antigen, respectively. Results: All the tested strains belonging to different leptospiral serogroups agglutinated to the antiserum against leptospiral genus-specific TR/Patoc I antigen with agglutination titers ranging from 1:256-1:512. A similar SDS-PAGE pattern of the OMPs from the three strains of leptospira with different virulence was shown and the molecular weight of a major protein fragment in the OMPs was found to be approximately 60 KDa. A positive protein fragment with approximately 32 KDa confirmed by Western blot, was able to react with the antiserum against leptospiral genus-specific TR/Patoc I antigen, and was found in each the OMPs of the three stains of leptospira. Conclusion: There are genus-specific antigens on the surface of L.interrogans and L.biflexa. The OMP with molecular weight of 32 KDa may be one of the genus-specific protein antigens of leptospira.     

Determination of the genus-specific antigens in outer membrane proteins from the strains of Leptospira interrogans and Leptospira biflexa with different virulence

INTRODUCTIONInfectionbyL.interrogansischaracterizedbyhemorrhage,diarrhea,jaundice,severerenalim-pairment,andasepticmeningitis.Leptospirosisisspreadfromanimalurinetohumansandiscon-sideredtobethemostwidespreadanthropozoono-sisintheworld.Thisdiseaseiscommoninfarmersandveterinarians,butcanalsobetransmittedthroughcontaminatedwaterinfloodedareas.Inparticular,leptospirosisisoneofthemostimportant2001;Kupeketal.,2000).LeptospiraisdividedintoLeptospirainterrogansandLeptospirabiflexa.Theformerispa…     

Epigallocatechin-3-gallate affects the growth of LNCaP cells via membrane fluidity and distribution of cellular zinc

Objective: To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:l was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane,decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.     

Ursolic acid inhibits proliferation and induces apoptosis of HT-29 colon cancer cells by inhibiting the EGFR/MAPK pathway

rectal cancer.     

Effects of insulin-like growth factor-1 on the properties of mesenchymal stem cells in vitro

Objective  

To explore the effects of insulin-like growth factor-1 (IGF-1) on migration, proliferation and differentiation of mesenchymal stem cells (MSCs).     

雌激素和Glu-NMDA受体通路与学习记忆相关性的研究进展

雌激素(estrogen,E)是维持女性第二性征最主要的甾体物质,其在神经系统也发挥广泛的药理作用,如抗脑缺血再灌注损伤减少梗死面积,抗自由基形成,调节兴奋性氨基酸释放等.雌激素自身作为一种抗氧化剂能够通过调节体内氧化还原平衡发挥神经保护作用.另外,雌激素在神经系统药理作用的发挥与其受体密不可分,经典的雌激素受体(estrogen receptor, ER)主要位于细胞核内,包括ER-α和ER-β两种亚型,二者均可在大脑皮质和海马表达:卵巢切除大鼠学习记忆能力降低的同时,ER-α在大脑皮质区和海马区表达也显著减少;ER-β基因敲除能够严重影响学习记忆行为、长时程增强(long term potentiation,LTP)和突触强度,该受体可能参与了高级脑功能的调节.N-甲基-D-天冬氨酸(N-methyl-D-aspartic acid,NMDA)受体作为与学习记忆密切相关的受体,与雌激素受体在海马区存在共表达.雌激素可能通过膜相关的雌激素受体快速激活ERK1/2信号转导通路,进一步诱导NMDA受体NR2B亚基磷酸化,激活NMDA受体,三者均会影响突触可塑性.本文就雌激素及其受体和Glu-NMDA受体通路与学习记忆的相关性进行综述.     

热休克蛋白90α在人胃癌与癌旁及淋巴结转移癌中表达的研究

目的 :研究热休克蛋白 90α(HSP90α)在人胃癌与癌旁及淋巴结转移癌中的表达。方法 :应用兔抗人HSP90α多克隆抗体SP免疫组化方法检测 93例胃癌、癌旁和淋巴结转移癌组织。结果 :HSP90α在胃癌、胃旁及淋巴结转移癌中的阳性率分别为 86.5 %、5 9.5 %、71.4 %。HSP90α在胃癌中的表达率高于癌旁 (P <0 .0 5 ) ,而与淋巴结转移癌差异不显著。结论 :HSP90α在人胃癌中表达值高于癌旁 ,此现象说明HSP90α和癌的产生和发展有密切联系。     

大学生感觉寻求与网络成瘾的关系研究

采用中国版大学生感觉寻求问卷和网络成瘾问卷,对294名大学生进行感觉寻求和网络成瘾情况及其相互关系调查。结果:感觉寻求存在显著性别差异,男生的感觉寻求水平高于女生;网络成瘾存在显著的性别差异,男生比女生更容易对网络上瘾;感觉寻求总分和去抑制与网络成瘾的相关显著。结论:感觉寻求和网络成瘾之间确实存在一定的关系。     

光谱法研究芦氟沙星与人血清白蛋白的相互作用

用光谱法研究水溶液中芦氟沙星与人血清白蛋白的结合反应，分别测定了295，310K两个不同温度下二者的结合常数心和结合位点数n，探讨了其荧光猝灭机制；根据热力学参数确定了芦氟沙星与人血清白蛋白之间的作用力类型，以氢键或范德华力为主，并运用Foster偶极-偶极非辐射能量转移原理。测定了其相互结合时授．受体间的距离r；采用同步荧光技术考察确定芦氟沙星对人血清白蛋白构象产生一定的影响．     

中苏两党关于斯大林问题的争论评析

斯大林的评价问题始终是中苏论战的焦点之一。苏共对斯大林采取抽象肯定、具体否定的办法，是片面的、错误的，认识的深度也不够，但对斯大林晚年所犯错误进行批判，反对个人崇拜却是必要的、符合苏联社会历史发展的客观要求的，对社会主义国家后来改革和冲破斯大林模式产生了深远的影响，从总体上应该肯定。中共一开始强调对斯大林要进行全面分析，不能把所有错误都推到斯大林一个人身上，是完全正确的，但中共对斯大林问题的分析难以摆脱当时认识水平的局限，中苏论战高潮期又从原来的立场上后退，否定批判斯大林的积极意义，助长了个人崇拜思想的膨胀，结果，毛泽东又把斯大林犯过的错误重复了一遍，酿成历史的悲剧。     

WTO与美国法关系论

WTO体制与美国贸易法有密切的关系，它的产生、制度变迁，尤其是其主流价值观受美国法的影响很大。对二关系的考察有助于我们认识WTO制度与价值观的演变矛盾，在实践中把握其政治经济关系的本质。     

略论正刊与增刊的关系

目前,虽然增刊的“口碑”不是太好,但各期刊社出版增刊已是一种普遍现象。这里有追求经济效益的因素在里边,但同时出版增刊也是有一定的意义和作用的。《辽宁师范大学学报》(自然科学版)出版增刊的实践说明只有正刊办得好,才能为增刊的出版提供可能的平台;同时,增刊是正刊的有益补充。     

氢氯噻嗪与牛血清白蛋白的相互作用

用荧光光谱法研究了氢氯噻嗪(Hydrochlorothiazide,HCT)与牛血清白蛋白(BSA)的相互作用。实验结果表明,HCT与BSA作用的猝灭常数随着温度的升高而降低,HCT可以有规律地使BSA内源荧光猝灭,其猝灭机理可认为是HCT与BSA形成复合物的静态猝灭。通过测定和计算不同温度下该结合反应的结合常数和结合位点数,并根据热力学方程求得了结合反应的ΔG、ΔH和ΔS等热力学参数,根据所得结果推断出HCT与BSA间的主要作用力类型是疏水作用力。同时,从分子荧光寿命进一步证明HCT与BSA的荧光猝灭机制为静态猝灭。