免疫受损大鼠铜绿假单胞菌肺部感染后肺表面活性物质的改变

目的了解免疫受损宿主肺部铜绿假单胞菌（PA）感染后肺表面活性物质(PS)的改变。方法建立免疫受损宿主肺部PA感染的大鼠模型,同时设置对照组,在接种PA前后不同时间行左侧支气管肺泡灌洗,测定灌洗液中的总蛋白(TP)、总磷脂(TPL)、饱和磷脂酰胆碱(DSPC)、肺表面活性物质蛋白(SP-A)及右侧肺组织湿/干比。结果感染PA后,大鼠支气管肺泡灌洗液(BALF)中TPL及DSPC较感染前并无明显改变,但DSPC/TPL、DSPC/TP下降;免疫受损大鼠SP-A和SP-A/TP在感染前与对照组差别无显著性,但感染后下降明显,分别由感染前的（4.1±1.2）μg/ml、（22.5±5.0）μg/mg下降至接种后6h的（1.8±1.1）μg/ml、（1.4±0.7）μg/mg（P<0.05）,低于同期对照组大鼠水平［分别为（4.2±1.5）μg/ml,（11.7±8.1）μg/mg,P<0.05］,免疫受损大鼠TP及湿/干比升高更明显,两组大鼠SP-A与TP、湿/干比的改变呈负相关;免疫受损大鼠BALF中SP-A/TPL、SP-A/DSPC较感染前下降,感染后6h达最低,且感染后6～9h比例明显低于同期对照组。结论免疫受损大鼠PA肺部感染时,磷脂改变表现为DSPC/TPL、DSPC/TP降低,SP-A的下降与肺损伤严重程度有关,肺表面活性物质中磷脂与蛋白成分的改变不同步,SP-A下降幅度更明显。     

粒细胞减少大鼠铜绿假单胞菌肺部感染模型的建立及炎症反应研究

目的 建立粒细胞减少铜绿假单胞菌(PA)肺部感染的大鼠模型,研究其炎症反应的特点.方法 将50只健康雄性清洁级Sprague-Dawley大鼠随机分为用药组(25只)与对照组(25只),用药组联合应用环磷酰胺与醋酸可的松7 d.经气管内滴入0.2ml6×108CFU/ml的美国标准菌库(ATCC)27853 PA菌液诱导肺部感染,对接种前、后3、6、9、24 h的支气管肺泡灌洗液(BALF)、肺组织进行细菌学、细胞学、病理学研究,并测定BALF中的总蛋白(TP)和肺组织湿/干比(W/D).结果 (1)经药物处理后,用药组大鼠[(141±8)g]的体重减轻,与对照组[(201±14)g]比较,差异有显著性(P＜0.001);用药组[(0.06±0.05)g]胸腺萎缩,与对照组[(0.40±0.10)g]比较,差异有显著性(P＜0 001);用药组外周血及BALF中白细胞数[(0.9±0.3)×109/L]与对照组[(7.3±1.9)× 109/L]比较,差异有显著性(P＜0.001).(2)接种PA后,BALF及肺组织中均培养到PA,W/D及TP较感染前明显升高,用药组大鼠活动度差,病死率高,肺组织充血、水肿、出血严重,/D及TP升高程度重于对照组;(3)大鼠接种PA后,肺部中性粒细胞(PMN)升高,6～9 h达高峰,但用药组[(102±13)个/高倍视野]反应弱于对照组[(291±20)个/高倍视野],两组比较差异有显著性(P＜0.01);对照组TP改变与肺部PMN浸润程度有一定相关性(r=0.926,P＜0.05),但用药组W/D、TP的改变与肺部PMN浸润程度无明显相关(r=0.24、0.58,P=0.70、0.31).结论 外周血粒细胞减少大鼠肺损伤严重而中性粒细胞浸润程度较轻,提示这种严重的肺损伤并不完全依赖于中性粒细胞的浸润强度.     

头孢他啶及头孢吡肟对产超广谱β内酰胺酶肺炎克雷伯菌大鼠肺炎的治疗作用

目的评价头孢他啶及头孢吡肟对产超广谱β内酰胺酶(ESBL)肺炎克雷伯菌大鼠肺炎的治疗效果。方法选取产ESBL肺炎克雷伯菌3种菌株,建立3组大鼠肺炎模型(kpn1、kpn2、kpn3组)。3种菌体外试验对头孢噻肟耐药,对哌拉西林/他唑巴坦敏感,对头孢他啶、头孢吡肟为:1组均敏感;2组头孢他啶敏感,头孢吡肟耐药;3组头孢吡肟敏感,头孢他啶耐药。每组分5个治疗亚组(头孢他啶、头孢吡肟、哌拉西林/他唑巴坦、头孢噻肟、生理盐水对照亚组),治疗96h后进行评价。结果kpn1组:哌拉西林/他唑巴坦、头孢他啶、头孢吡肟亚组生存率(75.0%、76.9%、80.0%)明显高于头孢噻肟、生理盐水对照亚组(36.0%、32.0%),前3组肺组织匀浆活菌计数[(10.8±2.8)、(11.1±3.2)、(11.0±3.7)lgCFU/g]明显低于头孢噻肟、生理盐水对照亚组[(15.7±5.6)、(16.0±5.5)lgCFU/g]。kpn2组:哌拉西林/他唑巴坦、头孢他啶亚组生存率(79.2%、73.1%)明显高于头孢噻肟、生理盐水对照亚组(42.3%、33.3%),前2组肺组织匀浆活菌计数[(10.7±2.3)、(11.0±2.7)lgCFU/g]明显低于头孢噻肟、生理盐水对照亚组[(15.5±5.4)、(15.8±4.6)lgCFU/g]。kpn3组:哌拉西林/他唑巴坦、头孢吡肟亚组生存率(80.8%、75.0%)明显高于头孢噻肟、生理盐水对照亚组(37.5%、34.6%)。结论体外敏感的头孢他啶、头孢吡肟治疗产ESBL肺炎克雷伯菌大鼠肺炎,可提高生存率,降低肺组织lgCFU/g,与哌拉西林/他唑巴坦作用相当。     

急性下呼吸道感染增加老年慢性心力衰竭患者血栓危险的临床观察

目的评价慢性心力衰竭(心衰)和心衰合并下呼吸道感染患者的血栓风险。方法入选51例慢性心衰患者(CHF组)、26例慢性心衰合并下呼吸道感染患者(CHF+RTI组)、32例健康对照者(对照组),ELISA法检测血浆凝血酶-抗凝血酶Ⅲ复合物(TAT)、凝血酶原片段1+2(F1+ 2)、D-二聚体(D-D)、纤溶酶-抗纤溶酶复合物(PAP)、β-血小板球蛋白(β-TG)和血小板因子4(PF4)。结果3组的6种血栓标志物存在差异,CHF组的各项指标均高于对照组,TAT、F1+2、D-D、PAP、β-TG、PF4分别为(6．29±2．02)与(3.59±1．74)μg／L、(1．43±0．56)与(0．86±0．29)nmol／L、(1.57±0．66)与(0．46±0．28)mg／L、(397．0±117．7)与(238．1±58．1)、(30．84±11．37)与(23．10±7．72)μg／L、(10．28±4．03)与(7．40±3．07)μg／L,差异有统计学意义(均为P<0．01)。CHF组除PAP与CHF+RTI组[分别为(397.0±117．7)与(408．8±87．7)μg／L]比较差异无统计学意义(P >0．05)外,其余5项指标均显著低于CHF-RTI组[TAT:(6．29±2．02)与(8．14±2．51)μg／L,P< 0.01;F1+2:(1.43±0．56)与(1．83±0．52)nmol／L,P<0．01;D-D:(1．57±0．66)与(1．90±0．56)mg／L,P<0．01;β-TG:(30．84±11．37)与(41．92±12．91)μg／L,P<0．01;PF4:(10．28±4．03)与(14．51±4．39)μg／L,P<0．01]。各组内β-TG与PF4呈正相关(r分别为0．605、0．926、0．916,均为P<0．01)。结论慢性心衰患者存在血栓前状态,若合并急性下呼吸道感染,则进一步增加血栓形成的危险性。     

肿瘤坏死因子α对慢性阻塞性肺疾病大鼠模型呼吸肌蛋白质分解代谢的影响

目的研究肿瘤坏死因子α（TNF-α）对慢性阻塞性肺疾病（COPD）模型大鼠呼吸肌蛋白质分解代谢率的影响。方法成年雄性Wistar大鼠90只，分为模型组70只，对照组20只，采用反复熏香烟和气管内注入猪胰弹性蛋白酶的方法建立COPD大鼠模型，模型建立成功2周后，以低于对照组大鼠平均体重的90％作为判断发生营养不良的标准，随机抽取已出现营养不良的大鼠10只，采用尾静脉注射TNF-α单克隆抗体0．1mg／kg进行干预，连续干预4d，继续饲养动物10d，处死全部动物。酶联免疫吸附测定法测定膈肌及肋间内肌匀浆中TNF-α含量；反相高效液相色谱荧光法测定膈肌和肋间内肌匀浆中3-甲基组氨酸（3-MH）及酪氨酸含量。结果营养不良组大鼠膈肌和肋间内肌的TNF-α含量[（125±11）和（119±11）pg／g]显著高于对照组[（64±5）和（59±5）pg／g]，营养不良组大鼠膈肌和肋间内肌匀浆中3-MH含量[（7．1±0．6）和（7．4±0．6）nmol／g]和酪氨酸含量[（639±24）和（660±25）nmol／g]均显著高于对照组[（4．0±0．5）、（4．2±0．3）和（557±24）、（579±26）nmol／g]，膈肌和肋间内肌TNF-α含量与蛋白质分解代谢率呈阴显正相关（r=0．854。P〈0．01）。TNF-α单克隆抗体干预后，蛋白质分解代谢率降低。结论COPD大鼠模型呼吸肌蛋白质分解代谢率增高，这种现象在COPD大鼠模型中发生营养不良的大鼠表现更为明显。TNF-α是引起COPD大鼠呼吸肌蛋白质分解代谢率增高的因素之一。     

缺氧肺动脉高压大鼠肺组织中白细胞介素6和Janus激酶表达的变化

目的　研究缺氧肺动脉高压 (HPH)肺组织中白细胞介素 6(IL 6)及Janus激酶 (JAKs)表达的变化。方法　雄性Wistar大鼠 60只 ,随机分为缺氧 1周 (H1)、缺氧 2周 (H2 )、缺氧 3周 (H3)、缺氧4周 (H4)和常氧 (N)组 ,每组 12只。常压缺氧舱复制HPH大鼠模型。应用逆转录 聚合酶链反应 (RT PCR)检测肺组织IL 6和JAKsmRNA的表达水平 ;免疫组化法检测肺组织JAKs蛋白的含量和细胞形态学变化。结果　 (1)H1、H2 和H3 组大鼠肺组织IL 6mRNA水平 (分别为 1 67± 0 0 9、2 2 6± 0 12、1 55± 0 11)显著高于N组 (1 2 0± 0 11,P均 <0 0 1) ;H1、H2 和H3 组大鼠肺组织JAK1mRNA水平 (分别为 2 11± 0 0 9、2 85± 0 12、2 3 6± 0 13 )显著高于N组 (1 62± 0 10 ,P均 <0 0 1) ;H1、H2 和H3 组大鼠JAK2mRNA水平 (分别为 1 41± 0 0 7、2 0 2± 0 13、1 3 6± 0 0 9)显著高于N组 (1 0 1± 0 0 9,P均 <0 0 1) ;H1、H2 和H3 组大鼠肺组织JAK3mRNA水平 (分别为 0 86± 0 11、1 45± 0 10、0 91± 0 13 )显著高于N组 (0 55± 0 0 8,P均 <0 0 1) ;H1、H2 组大鼠肺组织TYK2mRNA水平 (分别为 1.3 6± 0 .10 ,1.76± 0 .11)显著高于N组 (0 .57± 0 .0 7,P均 <0 .0 1) ;其中H2 组大鼠肺组织表达IL 6和J     

增龄对纤维蛋白急性肺损伤大鼠肺组织单核巨噬细胞趋化因子-1表达的影响

目的研究增龄对纤维蛋白诱导急性肺损伤大鼠肺组织单核巨噬细胞趋化因子-1 (MCP-1)表达的影响,探讨老年大鼠对炎性刺激易感的可能机制。方法青年及老年大鼠均根据腹腔注射不同的药物随机分为4组:对照组、脂多糖组、氨甲环酸组、肝素组。应用免疫组化分析纤维蛋白沉积;应用Western blot和Northern blot方法分别检测肺组织MCP-1蛋白质和基因表达。结果(1)青年和老年对照组大鼠肺组织内均无纤维蛋白沉积,老年大鼠脂多糖组、氨甲环酸组和肝素组均比青年大鼠相同干预组纤维蛋白沉积明显,差别均有统计学意义(18．5％±3．1％对12．3％±2．1％,32．5％±5．4％对24．1％±4．5％和20．8％±3．6％对12．6％±1．8％,均为P<0．05);(2)青年和老年对照组大鼠肺组织内几乎无MCP-1表达,老年大鼠脂多糖组、氨甲环酸组和肝素组的MCP-1表达均较青年大鼠相同干预组上调,差异有统计学意义(0．40±0．02对0．20±0．03,0．60±0．05对0．25±0．04和0．30±0．01对0．20±0．04,均为P<0．05);(3)经纤维蛋白沉积增加量校正后,老年氨甲环酸组大鼠肺组织MCP-1的表达量仍显著高于青年大鼠氨甲环酸组(P<0．05)。结论纤维蛋白可上调急性肺损伤肺组织MCP-1基因及蛋白质表达,促进肺组织炎症反应;增龄能够促进肺组织纤维蛋白沉积,增强其上调肺组织MCP-1表达的作用。     

老年代谢综合征患者血胰岛素样生长因子1与代谢综合征的关系

目的了解代谢综合征(metabolic syndrome,MS)患者血胰岛素样生长因子1(IGF1)水平及其与MS的关系。方法按2005年国际糖尿病联盟(IDF)颁布的MS定义,将老年患者465例分为MS组255例和对照组210例。查空腹血糖、胰岛素、C肽、餐后2 h血糖、血脂全套、血IGF1并计算体质指数(BMI)。两组按是否并存糖尿病再分为糖尿病和非糖尿病两个亚组。结果(1) MS组除高密度脂蛋白胆固醇(HDL-C)低于对照组外,其他血液指标均高于对照组(P<0．01);两组IGF1水平与年龄、BMI均呈负相关(P<0．05)。(2)MS糖尿病组IGF1(163．5±128．1)μg／L、胰岛素(14．3±10．5)mU／L高于MS非糖尿病组(114．0±52．6)μg／L、(8．46±4．4)mU／L,C肽(1．1±0．4)μg／L低于MS非糖尿病组(2．5±0．4)μg／L,均为P<0．01;IGF1水平与胰岛素、C肽无相关性,与冠心病呈负相关(P<0．05)。(3)对照糖尿病组IGF1(129．2±49．1)μg／L低于对照非糖尿病组(136．6±80．5)μg／L,胰岛素(14．1±11．7)mU／L、C肽(3．28±2．23)μg／L高于对照非糖尿病组(10．3±6．1)mU／L、(2．9±1．7)μg／L,P<0．01或0．05。对照组IGF1与C肽负相关,与甘油三酯正相关;对照糖尿病组IGF1与胰岛素、C肽负相关(均为P<0．01或0．05)。结论MS患者存在高血IGF1现象,这与单纯糖尿病患者低IGF1不同;MS患者IGF1水平较低时发生冠心病的机率较高。     

白细胞介素5和嗜酸粒细胞趋化因子在支气管哮喘大鼠肺和骨髓信号传导中的作用

目的探讨支气管哮喘(简称哮喘)大鼠模型中白细胞介素5(IL-5)和嗜酸粒细胞趋化因子(eotaxin)是否参与肺和骨髓间信号传导,观察不同干预措施的影响。方法清洁级雄性Wistar大鼠40只,按随机数字表法分为正常对照组和哮喘组,每组20只。用卵白蛋白(OVA)致敏和激发制作哮喘模型,于激发后30 min及6、12、24、48 h处死大鼠,分别取外周血涂片、骨髓细胞涂片。肺组织以10％甲醛固定做石蜡切片。将血涂片、骨髓涂片、肺组织切片行苏木精-伊红(HE)染色,观察细胞总数和嗜酸粒细胞(EOS)比例。取不同时间点肺组织匀浆,用酶联免疫吸附测定(ELISA)法测定肺组织匀浆IL-5和eotaxin浓度。将不同时间点的肺组织匀浆与正常对照组和哮喘组大鼠骨髓细胞共同孵育,并分别加入地塞米松(DXM)、半乳凝素3(Galectin-3)、孟鲁司特钠、抗IL-5抗体进行干预,采用抗IL-5、抗IL-SRα、抗eotaxin、抗CD34和抗CC趋化因子受体3(CCR3)多克隆抗体进行免疫组化染色,检测两组骨髓细胞中EOS计数和IL-5+细胞、IL-5Rα+细胞、CCR3+细胞、eotaxin+细胞、CD34+细胞的百分比。结果哮喘大鼠外周血、骨髓、肺组织中EOS数分别为0．020 0±0．002 0、0．023±0．003、0．025 0±0．009 0,正常对照组分别为0．010 0±0．003 0、0．009±0．003、0．009 0±0．002 0,两组比较差异有统计学意义(t值分别为2．547、2．718、2．718,P均<0．05);哮喘大鼠肺组织匀浆于激发6 h的IL-5为(89．3±2．4)pg/ml,12 h的eotaxin水平为(4．9±0．5)pg／ml,48 h均回到基线[(1．45±0．23) pg／ml]水平;除30 min外,各时间点哮喘大鼠肺组织匀浆均能诱导正常对照组或哮喘组大鼠骨髓细胞中CD34+、EOS、IL-5+、IL-SRα+、CCR3+、eotaxin+细胞表达增加,Galectin-3干预哮喘大鼠骨髓细胞后,骨髓EOS、IL-5+、IL-5Rα+、CCR3+、eotaxin+和CD34+细胞表达减少(分别为0．021±0．005、0．074±0．007、0．138±0．014、0．067±0．010、0．040±0．005、0．087±0．012)。结论IL-5 mRNA转录选择性抑制物(Galectin-3)能抑制EOS炎症,有可能成为一种特异性的抗哮喘药物。     

姜黄素干预对博莱霉素诱导的大鼠肺纤维化的影响

目的利用博莱霉素诱导的大鼠肺纤维化模型观察姜黄素对肺纤维化的作用效果及其机制。方法54只大鼠按随机数字表法分为正常对照组、博莱霉素组和姜黄素组，每组18只。正常对照组：于实验0d气管内一次性注入生理盐水2ml／kg，第14天起每日腹腔注射生理盐水0．5ml／kg；博莱霉素组：气管内一次性注入博莱霉素屯制剂5mg／kg，第14天起每日腹腔注射6％乙醇和6％聚乙二醇混合溶液0．5ml／ks；姜黄素组：气管内一次性注入博莱霉素屯制剂5mg／kg，第14天起每日腹腔注射姜黄素（溶于6％乙醇和6％聚乙二醇混合溶液）50mg／kg。分别于第17、21、28天各取6只大鼠处死，取肺组织行苏木精-伊红（HE）和Masson染色以观察其病理变化；用逆转录-聚合酶链反应（RT-PCR）法测定肺组织中转化生长因子β1（TGF-β1）和干扰素γ（IFN-γ）mRNA表达；用消化法测定羟脯氨酸含量，收集支气管肺泡灌洗液（SALF）测定TGF-β1、IFN-γ的含量。结果（1）肺泡炎评分：姜黄素组与博莱霉素组在第28天分别为（1．3±0．5）分、（2．0±0．9）分，两组比较差异有统计学意义（q=3．26，P〈0．05）；（2）肺纤维化评分：姜黄素组与博莱霉素组在第21天分别为（1．3±0．5）分、（1．8±0．4）分，第28天分别为（1．2±0．4）分、（2．2±1．O）分，两组比较差异有统计学意义（q值分别为3．33、4．00，P均〈0.05）；（3）肺组织羟脯氨酸含量：姜黄素组与博莱霉素组在第28天分别为（1．75±0．36）μg／g、（2．47±0．24）μg／g，两组比较差异有统计学意义（q=7．20，P〈0．01）；（4）BALF中TGF-β1含量：姜黄素组与博莱霉素组在第21天分别为（20±3）ng／L、（39±7）ng／L，第28天分别为（24±4）ng／L、（40±7）ng／L，两组比较差异有统计学意义（q值分别为5．30、6．27，P均〈0．05）；（5）肺组织中TGF-β1mRNA的表达：姜黄素组与博莱霉素组在第21天分别为0．51±0．11、0．59±0．13，第28天分别为0．50±0．07、0．64±0．11，两组比较差异无统计学意义（q值分别为1．55、3．13，P均〉0．05）；（6）BALF中IFN-γ含量：姜黄素组与博莱霉素组在第21天分别为（28±5）ng／L、（35±13）ng／L，第28天分别为（30±11）ng／L、（39±13）ng／L，两组比较差异无统计学意义（q值分别为1．85、2．03，P均〉0．05）；（7）肺组织中IFN-γmRNA的表达：姜黄素组与博莱霉素组在第21天分别为0．49±0．17、0．50±0．08，第28天分别为0．52±0．15、0．52±0．11，两组比较差异无统计学意义（q值分别为0．17、0．00，P均〉0.05）。结论姜黄素可减轻博莱霉素诱导的大鼠肺泡炎和肺纤维化，其作用机制可能与抑制TGF-β1有关。     

Contribution of exotoxin A of Pseudomonas aeruginosa in acute and chronic experimental renal infection

The role of Pseudomonas aeruginosa exotoxin A was studied in acute and chronic pyelonephritis models employing an exotoxin A-producing strain PAO, and its toxin deficient mutant PAOT1. Interestingly, the mutant strain was found to be at an advantage in its ability to induce acute pyelonephritis and it induced severer renal pathology. No significant differences were observed in the ability of the parent strain and its mutant to induce chronic renal inflammation.     

Elastase activity in bronchoalveolar lavage fluid from oxygen-exposed, Pseudomonas-infected baboons

The adult respiratory distress syndrome is a major cause of morbidity and mortality in critical care patients. Lung injury in this syndrome is frequently associated with lung infection. The combined insults result in an influx of neutrophils and damage to the pulmonary epithelium. We investigated whether active neutrophil elastolytic activity was present in the bronchoalveolar fluid in baboons with mild or moderate hyperoxic lung injury and infection. Group A (N = 7) was exposed for 6 days to FIO2 = 0.8 and then inoculated by intratracheal bolus with Pseudomonas aeruginosa strain DGI-R130 (PA); the FIO2 was reduced to 0.5. Group B (N = 6) was exposed to similar concentrations of inspired oxygen but inoculated with buffered saline. Antibiotics included parenteral penicillin and topical gentamicin and polymyxin B. All 3 were given continuously in group B but stopped 24 h prior to PA inoculation in group A. Bronchoalveolar lavage fluid was collected 1 week before oxygen administration, when the FIO2 was reduced (day 6 or 7) and prior to necropsy (day 11). Hemodynamic, pulmonary function, microbiological, and biochemical variables were studied. Injured, infected animals (group A) had significant elevations of mean pulmonary artery pressure and decreases in total lung capacity and PaO2 compared both to baseline and to group B at day 11. At autopsy, group A had significant increases of bronchoalveolar lavage fluid (BALF) neutrophils and bacterial pathogens. Elastase levels in BALF (equal to 0 at baseline) rose to 136 +/- 98 ng/ml in group A vs. 6 +/- 14 ng/ml in group B. The elastase was inhibited by inhibitors of serine proteases including ones specific for neutrophil elastase. On Sephacryl S-300 chromatography the elastase activity eluted near human alpha 2-macroglobulin and separated from other proteolytic activity. These studies demonstrate a significant level of elastase in BALF from injured, infected baboons compared to injured, uninfected animals.     

野生型铜绿假单胞菌PAO1和粘液型铜绿假单胞菌PA17播种型扩散的研究

目的:探讨PA17和PAO1生物膜形成过程中播种型扩散发生的相关机制.方法:SYTO9/PI双染色后,在激光共聚焦显微镜下观察1、3、5、7、9、t1d时PAO1及PA17生物膜形成的情况,real-time RT-PCR检测不同时间点PAO1及PA17的algR的表达.结果:PAO13 d时形成生物膜,但PA17此时...     

Pulmonary elastase activity in response to Streptococcus pneumoniae and Pseudomonas aeruginosa

Elastase activity generated during lung defense against aerobic bacteria was studied in an animal model. Bronchoalveolar lavage (BAL) fluid from hamsters inoculated with bacteria was assayed for elastase activity at 0, 2, 4, 6, and 8 h after inoculation using a synthetic substrate of elastase, succinyl-trialanine-nitroanilide (SLAPN). Streptococcus pneumoniae type 25 inoculation led to a peak elastase activity of 0.72 +/- 0.27 X 10(-3) units, not significantly different from baseline (0.41 +/- 0.08 X 10(-3) units) or saline control (0.33 +/- 0.18 X 10(-3) units). In contrast, inoculation with Pseudomonas aeruginosa strain PAO-1 (a species known to produce elastase as well as other virulence factors) produced peak elastase activity of 3.0 +/- 1.2 X 10(-3) units in BAL fluid, significantly higher than either pneumococcus type 25 or saline control (p less than 0.025). Inoculation with Pseudomonas aeruginosa strain E-64, an isogenic mutant of PAO-1 that produces a nonfunctional elastase, led to peak levels similar to the PAO-1 strain, suggesting that the presence of bacterial elastase was not the primary factor in BAL fluid elastase activity. Total numbers of granulocytes in BAL fluid from pneumococcus-inoculated animals (144 +/- 31 X 10(6] was significantly higher (p less than 0.05) than from either the PAO-1 (74 +/- 31 X 10(6] or E-64 (99 +/- 27 X 10(6] strains of Pseudomonas, Use of selective enzyme inhibitors of elastase, diisopropyl fluorophosphate and disodium ethylenediaminetetraacetate, implied that the majority of elastase activity in BAL fluid was due to a serine protease, of which granulocyte elastase is the primary source.(ABSTRACT TRUNCATED AT 250 WORDS)     

硫化氢在大鼠急性支气管哮喘模型中的变化及意义

目的观察卵白蛋白（OVA）诱导的大鼠急性支气管哮喘（简称哮喘）模型，内源性硫化氢（H2S）生成的变化以及应用外源性硫氢化钠（NaHS，H2S供体）处理对哮喘大鼠的影响，探讨气体信号分子H2S在哮喘发病中的作用。方法24只健康SD大鼠按随机数字表法分为正常对照组、哮喘组和NaHS干预组，每组8只。致敏后28d测定所有大鼠肺功能并观察大鼠支气管周围炎性细胞浸润程度并进行评分；采用敏感硫电极测定血浆及肺组织H2S的生成量；采用酶促反应法测定大鼠肺组织匀浆中胱硫醚-γ-裂解酶（CSE）活性；用Western blot法测定大鼠肺组织中CSE蛋白含量（每组3只）。结果哮喘组大鼠呼气峰流量（PEF）、血浆及肺组织中H2S分别为（2．90±0．70）L／s、（10±3）、（4．9±1．3）μmoL／L，对照组分别为（6．50±0．10）L／s、（54±10）、（24．1±8．0）μmoL／L，NaHS干预组大鼠分别为（5．70±0．50）L／s、（17±4）、（15．3±4．0）μmol／L，3组间比较差异有统计学意义（F值分别为112．13、110．10、27．34，P均〈0．01）；哮喘组大鼠肺组织匀浆每毫克蛋白中CSE活性和肺组织匀浆中CSE蛋白含量[用相对吸光度（A）值表示]分别为（1．00±0．10）nmol·min^-1·mg^-1、0．20±0．10，正常对照组分别为（1．80±0．10）nmo]·min^-1·mg^-1、0．90±0．30，NaHS干预组大鼠分别为（1．60±0．20）nmo]·min^-1·mg^-1、1．10±0．20，3组间比较差异有统计学意义（F值分别为79．39、12．28，P均〈0．05）；光镜下支气管周围炎性细胞浸润程度评分[用中位数（四分位数）]表示，正常对照组为1（0～1）分，哮喘组为3（2～4）分，NaHS干预组为1（1～2）分，3组间比较差异有统计学意义（H=16．93，P〈0．01）；哮喘组肺组织H2S含量与PEF呈正相关（r=0．74，P〈0．01）；与光镜下支气管周围炎性细胞浸润程度评分呈负相关（r=-0．64，P〈0．01）。结论内源性H2S参与了大鼠急性哮喘发病过程，外源性NaHS可以减轻哮喘气道炎症，对哮喘急性发病起到保护作用。     

In vivo regulation of virulence in Pseudomonas aeruginosa associated with genetic rearrangement.

A chronic pulmonary infection model was used to induce conversion to the mucoid phenotype by Pseudomonas aeruginosa PAO. At 6 months after initial inoculation, organisms isolated from infected lungs demonstrated the mucoid phenotype. Significant decreases (P less than .01) were seen in the levels of exotoxin A, exoenzyme S, phospholipase C, and pyochelin produced by the mucoid P. aeruginosa PAO rat lung isolates that returned to parental levels after reversion to the nonmucoid phenotype. In addition, lipopolysaccharide of the mucoid PAO lung isolates failed to react with serotype B-specific antibody in contrast to the original PAO and the revertant PAO organisms. Digestion of chromosomal DNA and hybridization with P. aeruginosa virulence factor-specific probes demonstrated that conversion to the mucoid phenotype was associated with rearrangement of chromosomal DNA upstream of the exotoxin A gene. Analysis of DNA from revertant organisms revealed hybridization patterns identical to the original PAO organism.     

Iontophoretic transmyocardial drug delivery. A novel approach to antiarrhythmic drug therapy.

BACKGROUND. Antiarrhythmic drugs often fail to achieve therapeutic effects without toxic systemic levels. Direct transport of drugs into the myocardium may circumvent this problem and may also provide new insights into antiarrhythmic drug effect on arrhythmogenic tissues. In a canine model, procainamide (PA) was delivered iontophoretically using pulsed current synchronized with the ventricular depolarization via an implantable defibrillator patch electrode that was modified to contain a 3.6-ml chamber. Myocardial tissue concentrations of PA were evaluated in 7-day myocardial infarcts (n = 16) that were exposed to 10 minutes of iontophoretic PA delivery and compared with passive diffusion (n = 5) and intravenous (n = 16) PA. These dogs were followed for 3 hours. The infarcted tissue PA levels were compared with normal myocardium. Coronary and systemic blood levels of PA, effective refractory period (ERP), diastolic threshold, and efficacy of ventricular tachycardia (VT) suppression were evaluated throughout the follow-up period. METHODS AND RESULTS. Three hours after 10 minutes of iontophoretic, passive, and intravenous PA, the epicardial layer concentration in the center of the infarcted zone was 840 +/- 853 micrograms/g, 93 +/- 90 micrograms/g, and 15 +/- 8 micrograms/g of tissue, respectively. In the endocardial layer, the PA concentrations with iontophoresis were 38 +/- 57 micrograms/g and were significantly higher than those achieved with either passive diffusion 38 +/- (4 +/- 2 micrograms/g) or with intravenous delivery (11 +/- 5 micrograms/g) (p less than 0.05). Epicardial tissue PA concentrations 3 hours after iontophoresis, passive diffusion, and intravenous PA in the normally perfused tissues were 14 +/- 13 micrograms/g, 3 +/- 2 micrograms/g, and 16 +/- 8 micrograms/g of PA, respectively. Venous blood levels were 2 +/- 3 micrograms/ml 3 hours after iontophoresis, 1 +/- 1 microgram/ml 3 hours after passive PA delivery, and 11 +/- 7 micrograms/ml with intravenous administration (p less than 0.05 intravenous versus passive and iontophoresis). Iontophoretic delivery of PA resulted in 22 +/- 29 msec ERP prolongation intramurally in the infarcted zone with no significant normal tissue ERP prolongation. Passive delivery of PA produced no significant changes in ERP. After intravenous infusion, the ERP in the infarcted zone increased by 35 +/- 29 msec and 13 +/- 12 msec in the normal tissue. Sustained monomorphic VT was induced in 20 animals. In one of these animals, only nonsustained VT could be induced at baseline; however, after intravenous PA, VT could be induced and remained inducible throughout the 3-hour follow-up period. In the iontophoretic delivery group, PA suppressed VT in all of the animals, with termination time ranging from 20 seconds to 7 minutes. In three cases, sustained monomorphic VT could be reinduced, two after 60 minutes and one after 120 minutes. However, in seven dogs, VT could not be induced during the 3-hour follow-up period. None of the dogs in which PA was delivered iontophoretically into the infarcted myocardium developed VT that was not induced before delivery of the drug. Intravenous PA administration resulted in VT suppression in one of 10 dogs. In two dogs, VT could not be induced before intravenous infusion of PA. However, after intravenous PA, VT could be induced. Immunohistochemical mapping of the PA within the infarcted tissue revealed transmural PA distribution. CONCLUSIONS. These data show that 1) the delivery of high transmural concentrations of PA directly into infarcted myocardium is both feasible and effective...     

Suppression of gastric H2-receptor mediated function in patients with bronchial asthma and ragweed allergy

We have previously demonstrated a depression of airway, vascular, and cutaneous H2-histamine receptor function in sheep with experimental allergic asthma. In the present investigation, we wished to determine if there is a depression of gastric H2-receptor function in subjects with allergic bronchial asthma. In eight normal subjects and seven subjects with allergic bronchial asthma and bronchial reactivity to ragweed antigen, gastric H2-receptor function was assessed by measuring basal and maximal stimulated acid output following pretreatment with a placebo or the H2-antagonist, cimetidine. Maximal stimulated acid output was defined as the peak acid output (PAW mEq/hr) of hydrochloric acid following a subcutaneous injection of histalog (1.5 mg/kg), and selective H2-stimulation as delta PAO = PAOplacebo-PAOcimetidine. While basal acid output was not different between the two groups, mean (+/- SD) PAO was significantly lower in the asthmatic group (14.0 +/- 8.2 mEq/hr) than the normal group (27.9 +/- 9.4 mEq/hr) (p less than 0.01). Mean PAO expressed as percent of predicted maximum was 112 +/- 36 percent in the normal group and 61 +/- 34 percent in the asthmatic group (p less than 0.01). Mean delta PAO was significantly higher in the normal group (17.1 +/- 4.8 mEq/hr) than in the asthmatic group (7.0 +/- 5.3 mEq/hr) (p less than 0.005) indicating suppressed selective H2-receptor stimulation in the latter. We conclude that in subjects with bronchial asthma and marked bronchial hyperreactivity to ragweed antigen, there is a depression of gastric H2-histamine receptor function.     

维生素A对大鼠实验性肺气肿肺泡壁细胞增殖与凋亡的影响

目的 观察维生素A对大鼠实验性肺气肿的干预作用,探讨其对肺泡壁细胞增殖和凋亡的影响.方法 雄性Wistar大鼠24只,采用随机数字表法分为对照组、模型组和维生素A组,每组8只.模型组、维生素A组在实验之初采用气管内滴入2 kU/kg弹性蛋白酶复制肺气肿模型,对照组气管内滴入等量生理盐水,术后第5周起进行药物干预,维生素A组每天给予100 kU/kg维生素A灌胃,其他两组给予等量油剂,共进行4周.实验第8周后处死大鼠.行HE染色观察各组大鼠肺泡的病理学变化,免疫组织化学法观察增殖细胞核抗原(PCNA)的表达,末端脱氧核酸转移酶介导的dUTP缺口末端标记(TUNEL)法观察肺泡壁细胞的凋亡.统计学处理采用单因素方差分析,多组间两两比较采用LSD法.结果 模型组平均肺泡数(43±11)明显低于对照组(101±15)和维生素A组(56±8);平均肺泡面积[(3763±504)μm2]明显高于对照组[(1919±270)μm2]和维生素A组[(2710±276)μm2];增殖指数[(30.7±7.6)%]明显高于对照组[(9.9±1.8)%],明显低于维生素A组[(45.4±5.0)%];凋亡指数[(22.0±4.6)%]明显高于对照组[(9.8±1.7)%]和维生素A组[(17.3±3.5)%];增殖指数/凋亡指数(1.03±0.19)与对照组(1.45±0.52)无明显差别,明显低于维生素A组(2.73±0.64).结论 维生素A能促进弹性蛋白酶诱导大鼠实验性肺气肿的肺泡壁细胞增殖并抑制其凋亡,使肺泡壁细胞增殖/凋亡的平衡向增殖倾斜,从而对大鼠实验性肺气肿起到一定的改善作用.