卡维地洛对氧自由基诱导的内皮细胞内源性一氧化氮合酶抑制物代谢的影响

目的： 观察卡维地洛对氧自由基（OFR）培养的人脐静脉内皮细胞（HUVECs）二甲精氨酸-二甲赖氨酸水解酶 (DDAH)活性及表达的影响，以探讨卡维地洛对不对称二甲精氨酸（ADMA）代谢机制的影响。 方法： 采用改良的Jaffe法培养原代人脐静脉内皮细胞（HUVECs），取生长良好的3-6代HUVECs用于实验，分为①空白对照组：加DMEM培养液；②OFR组:加入OFR（0.01 mmol/L,0.1 mmol/L）；③OFR+卡维地洛组: 同时加入0.1 mmol/L OFR及卡维地洛（10 μmol/L）共孵24 h后, 检测上清液中一氧化氮（NO）、内皮素（ET）、ADMA含量、L-胍氨酸(L-cit)浓度及一氧化氮合酶（NOS）活性。用Western blotting法测定细胞裂解液中二甲基精氨酸-二甲基赖氨酸水解酶 (DDAH)的蛋白表达。 结果： OFR条件培养下,内皮细胞的代谢产物ADMA、ET的量均高于空白对照组,而NO的量及NOS的活性少于空白对照组;反映DDAH酶活性的L-cit浓度显著降低,且有浓度依赖性，而DDAH的表达无明显变化。卡维地洛干预组的ADMA、ET的量均低于OFR组，NOS活性及NO、L-cit浓度明显高于OFR组。 结论： OFR培养下，内皮损伤ADMA的增加与DDAH的活性减弱有关，而与DDAH的表达无关。卡维地洛通过增加DDAH活性促进ADMA代谢，使NOS活性增加，抑制OFR对内皮功能的损伤。     

多重耐药鲍曼不动杆菌相关耐药基因检测分析

目的为了解多重耐药鲍曼不动杆菌β-内酰胺酶（BLA）基因、氨基糖苷类修饰酶（AMFs）基因、消毒剂与磺胺类耐药基因（qacE△1-sul1）和1类整合子酶基因（intl1）存在情况。方法对2005年1—6月份临床分离的31株多重耐药菌株（耐哌拉西林、第三代头孢菌素、环丙沙星和阿米卡星），应用聚合酶链反应及序列分析方法分析其BLA、AMEs、qacE△1．sull和intl1基因类型。结果31株多重耐药鲍曼不动杆菌对多黏菌素B敏感，有3株（9．7％）对受试的其他18种抗菌药物均耐药。19株（61．3％）检出了β-内酰胺酶基因，其中TEM、PER、DHA阳性率分别为61．3％、19．4％、3．2％，未检出SHV、OXA-23、OXA-24、GES、IMP和VIM等基因。25株（80．6％）检出氨基糖苷类修饰酶基因，其中aac（3）-I、aac（6’）-I、ant（3”）-I、ant（2”）-I、aac（3）-Ⅱ、aac（6’）-Ⅱ阳性率分别为67．7％、45．2％、29．0％、22．6％、9．7％、3．2％。qacE△A1-sul1、intl1阳性率分别为80．6％、58．1％。分离株常见的基因组合是TEM＋qacE△1-sul1＋intl1和TEM＋PER＋qacE△1-sull＋intl1，分别占25．8％和19．4％。分离株AMEs的常见的基因组合是aac（3）-I＋aac（6’）-I和nnc（3）-I＋aac（6’）-I＋ant（2”）-I，分别占19．4％和12．9％。结论临床分离的多重耐药鲍曼不动杆菌TEM、nnc（3）-I、nnc（6’）-I、ant（3”）-I、ant（2”）-I、qacE△1-sul1和intl1基因携带率高。     

肌醇磷脂介导缺血脑损伤信号传导作用的研究进展

肌醇磷脂途径作为一种重要的细胞内信号传导通路，在神经系统特别是中枢神经系统发挥重要作用。本文旨在综述其在中枢神经系统的生理性作用。从而进一步探讨在脑缺血发生后这一通路的生理性代偿机制及病理生理机制。     

流感病毒RNA聚合酶蛋白PB1在小鼠中可诱导亚型间交叉免疫保护

目的探索流感病毒RNA聚合酶PB2和PB1亚基作为实验性流感疫苗候选抗原的可能性.方法以复制型质粒（pSCA）为载体分别构建表达甲1型和甲3型流感PB2和PB1的复制型DNA疫苗,免疫小鼠后分别用甲1型流感病毒（A/PR/8/34）进行鼻腔攻击,观察针对不同亚型流感病毒的复制型DNA疫苗的免疫保护效果.结果本实验所构建的复制型DNA疫苗在真核细胞中均可表达外源基因;本实验采用的复制型质粒载体（pSCA）与传统质粒载体（pcDNA3）在诱导小鼠产生抗体方面无差异,并且都诱导了偏向TH1类的免疫反应;表达甲1型和甲3型流感PB1基因的复制型DNA疫苗均可保护小鼠抵御甲1型流感病毒（A/PR/8/34）的攻击.结论表达甲型流感病毒PB1的复制型DNA疫苗能保护小鼠抵御同型和异型流感病毒的攻击,本实验为流感疫苗研究提供新的候选抗原.     

介绍一种制备特异性TF和特异性iRNA的方法

以乙肝疫苗、人喉癌细胞膜抗原为抗原，猪脾细胞为效应细胞，经体外免疫后收集应答细胞，制备ＰＳＨＢＶ－ＴＦ ＰＳＡＣ－ｉＲＮＡ。通过抗原特异性细胞免疫功能试验证实，ＰＳＨＢＶ－ＴＦ和ＰＳＡＣ－ｉＲＮＡ都能转移特异性细胞免疫功能。采用体外免疫法制备ＰＳＨＢＶ－ＴＦ和ＰＳＡＣ－ｉＲＮＡ是可行的，并且具有诸多优点。     

应用FISH、FCM检测APL PML/RARA融合基因及临床应用的研究

目的　研究应用荧光原位杂交技术 (FISH)、流式细胞技术 (FCM)检测急性早幼粒细胞白血病 (APL)PML/RARa融合基因及残留白血病细胞的意义。方法　应用CG、M -FISH、FCM对 30例APL患者初发和缓解期的骨髓标本进行分析 ,分别检测t(15 ;17)易位和PML/RARa融合基因及残留白血病细胞的存在。结果　对初发期骨髓标本进行CG和FISH分析发现 ,10 0 %具有t(15 ;17)易位 ,阳性核型占 6 8%～ 10 0 % ,其中有 8例还伴有其他异常 ;10 0 %具有PML/RARa融合基因 ,且阳性中期相的比例高达 96 %～ 10 0 % ;结果具有显著差异 (P <0 0 0 1)。对CR期的骨髓标本进行CG、FISH分析 ,CG为正常核型 ,FISH仍可检出 0 %～ 4 5 %的PML/RARa融合基因。对CR后 12个月的标本进行CG、FISH分析 ,CG均为正常核型 ;FISH仍可检出 0 %～ 37%的PML/RARa融合基因 ,较CR期有所降低。对这 30例APL患者初发期、完全缓解期及完全缓解后 12个月时进行了FCM检测 ,并得出定性结果。完全缓解期检测结果与M -FISH分析一致 ;对完全缓解后 12个月时M -FISH结果进行定性分析发现 30例患者中有 6例为融合基因阴性 ,相应的FCM定性分析结果却发现只有其中的 2例呈现阴性 ,其余 4例仍然为阳性。随访至CR后 2年 ,发现 7例PML/RARa融合基因阳性中期相比例较高 (CG分     

Alterations of plasma antioxidants and mitochondrial DNA mutation in hair follicles of smokers

The effects of long-term smoking on mitochondrial DNA (mtDNA) deletions in hair follicles were investigated in subjects with different antioxidant capacity. Twenty-two male smokers with a smoking index of greater than 5 pack-years and without any known systemic diseases were recruited for this study. Forty healthy nonsmoking males were included as controls. We found that the concentrations of ascorbate and alpha-tocopherol and the activities of glutathione S-transferase (GST) and glutathione peroxidase in blood plasma were significantly decreased in smokers. The levels of glutathione and protein thiols in whole blood and the incidence of a 4,977 bp deletion of mtDNA (dmtDNA) in hair follicles were significantly increased in smokers. A significantly higher incidence of the 4,977 bp dmtDNA was found in smokers with plasma GST activity less than 5.66 U/l (OR = 7.2, P = 0.020). Using multiple covariate ANOVA and logistic regression, we found that age and low plasma GST activity were the only two risk factors for the 4,977 bp dmtDNA. These results suggest that smoking depletes antioxidants and causes mtDNA deletions and that plasma GST may play an important role in the preservation of the mitochondrial genome in tissue cells of smokers.     

Distinct roles of pattern recognition receptors CD14 and Toll-like receptor 4 in acute lung injury

Acute lung injury (ALI) induced by lipopolysaccharide (LPS) is a major cause of mortality among humans. ALI is characterized by microvascular protein leakage, neutrophil influx, and expression of proinflammatory mediators, followed by severe lung damage. LPS binding to its receptors is the crucial step in the causation of these multistep events. LPS binding and signaling involves CD14 and Toll-like receptor 4 (TLR4). However, the relative contributions of CD14 and TLR4 in the induction of ALI and their therapeutic potentials are not clear in vivo. Therefore, the aim of the present study was to compare the roles of CD14 and TLR4 in LPS-induced ALI to determine which of these molecules is the more critical target for attenuating ALI in a mouse model. Our results show that CD14 and TLR4 are necessary for low-dose (300-microg/ml) LPS-induced microvascular leakage, NF-kappaB activation, neutrophil influx, cytokine and chemokine (KC, macrophage inflammatory protein 2, tumor necrosis factor alpha, interleukin-6) expression, and subsequent lung damage. On the other hand, when a 10-fold-higher dose of LPS (3 mg/ml) was used, these responses were only partially dependent on CD14 and they were totally dependent on TLR4. The CD14-independent LPS response was dependent on CD11b. A TLR4 blocking antibody abolished microvascular leakage, neutrophil accumulation, cytokine responses, and lung pathology with a low dose of LPS but only attenuated the responses with a high dose of LPS. These data are the first to demonstrate that LPS-induced CD14-dependent and -independent (CD11b-dependent) signaling pathways in the lung are entirely dependent on TLR4 and that blocking TLR4 might be beneficial in lung diseases caused by LPS from gram-negative pathogens.     

Multi-virulence-locus sequence typing clarifies epidemiology of recent listeriosis outbreaks in the United States

Multi-virulence-locus sequence typing (MVLST) was used to analyze isolates from two major listeriosis outbreaks in the United States in 1998 and 2002 that were due to consumption of contaminated hot dogs and turkey deli meat, respectively. MVLST demonstrated high epidemiological relevance and indicated that the two outbreaks were the result of one epidemic.     

应用肿瘤基因芯片筛选早期肺鳞癌相关基因

目的： 研究人早期肺鳞癌发生相关基因表达谱, 探讨肺鳞癌发生的分子机制。方法:选取人早期肺鳞癌组织以及相应正常组织，提取RNA, 与含480个与肿瘤相关基因的芯片杂交, 结果经SuperArray Image 软件分析后比较两种组织中的差异表达基因。结果:共筛查出差异表达基因192 条，其中表达上调基因127 条, 下调基因65条; 按照基因功能可分为运输载体、代谢相关基因、细胞信号转导分子、细胞骨架、转录调控因子基因。结论:基因芯片可用于早期肺鳞癌相关基因表达谱的筛查，可为明确早期肺鳞癌发生机制提供重要参考。