小窝蛋白1 对气道上皮细胞黏液高分泌的影响

目的:探讨小窝蛋白1(Cav-1)对脂多糖(LPS)诱导的气道黏液高分泌的影响。方法:体外培养人气道上皮细胞(16HBE),用LPS刺激细胞构建黏液高分泌模型,以Toll样受体4(TLR4)抑制剂E5564、核转录因子-κB(NF-κB)抑制剂PDTC、转染Cav-1质粒和siRNA为干预因素,将细胞随机分为对照组、LPS刺激组、LPS+Cav-1质粒组、LPS+Cav-1 siRNA组、LPS+阴性siRNA组、LPS+空质粒组、LPS+E5564组及LPS+PDTC组。四甲基偶氮唑盐法(MTT)检测各组细胞的活力;RT-PCR检测黏蛋白(MUC)5AC的转录水平;Western blot检测Cav-1、TLR4、磷酸化IκBα(p-IκBα)蛋白的相对含量;ELISA检测MUC5AC的分泌水平;激光共聚焦技术检测细胞内MUC5AC蛋白的分布和含量。结果:LPS刺激组细胞内TLR4、p-IκBα、NF-κB、MUC5AC转录及蛋白水平显著高于对照组(P值均0.05),过表达Cav-1可进一步增加上述指标的表达量,而下调Cav-1及给予E5564、PDTC可以抑制LPS引起的上述效应(P0.05)。结论:Cav-1可通过上调TLR4/NF-κB信号通路而加重LPS诱导的MUC5AC的表达量。     

Elafin基因重组气道上皮调节脂多糖诱导的人气道黏液高分泌

目的 探讨天然内生多肽Elafin对脂多糖诱导的气道黏液高分泌的调节机制.方法 构建人Elafin重组质粒pEGFP-N1-Elafin,转染正常人支气管上皮细胞HBE16,给予脂多糖(LPS)刺激,激光共聚焦扫描显微镜检测Elafin蛋白含量,Western blot法检测IKBa蛋白含量;荧光素酶报告基因检测系统测定核转录因子-κB(NF-κB)活性;RT-PCR检测Elafin和黏蛋白(MUC)SAC mRNA表达水平;ELISA法分析MUCSAC蛋白相对含量.结果 成功构建内生多肽Elafin真核表达载体pEGFP-N1-Elafin并转染HBEi6细胞.转染重组Elafin后Elafin蛋白含量及mRNA水平明显增加.与对照组相比,LPS刺激组IκBα蛋白含量降低,NF-κB相对活性明显增强,MUC5AC蛋白含量及mRNA水平也显著增加.转染重组Elafin后再予以LPS刺激,与单纯LPS刺激组相比,IκBα蛋白含量明显增加,NF-κB相对活性显著降低,MUCSAC蛋白含量及mRNA水平也明显降低.结论 天然内生多肽Elafin重组气道上皮可下调NF-κB的活性,降低脂多糖诱导的气道黏液高分泌.     

Elafin真核表达载体的构建及其对气道粘液高分泌的调节

目的:构建天然内生多肽Elafin真核表达载体,探讨其对气道粘液高分泌的影响。方法:抽提Elafin行RT-PCR获取Elafin cDNA,双酶切后将片段装载到pMD18-T载体上。以pMD18-T-Elafin为模板行PCR反应,产物胶回收并双酶切后定向克隆至pEGFP-N1上,转化,筛选,双酶切鉴定重组质粒。将pEGFP-N1-Elafin转染正常人支气管上皮细胞HBE16,给予脂多糖(LPS)刺激,Western blot检测细胞内Elafin蛋白的相对含量,RT-PCR检测各组Elafin mRNA和粘蛋白(MUC)5AC mRNA表达水平,荧光素酶报告基因检测系统测定核转录因子-κB(NFκ-B)的活性;ELISA法分析各组细胞MUC5AC蛋白的相对含量。结果:成功构建Elafin真核表达载体,转染重组Elafin的HBE16细胞成功表达Elafin蛋白。LPS刺激可增强NF-κB的活性,该活性在转染重组Elafin后显著降低;MUC5AC蛋白含量及mRNA水平在LPS刺激后也显著升高,在转染重组Elafin后二者的表达水平明显降低。结论:Elafin真核表达载体成功构建,初步发现Elafin可通过降低NFκ-B的活性来下调MUC5AC的表达,为进一步深入研究其对气道粘液高分泌的调节机制奠定了基础。     

槲皮素基于EGFR信号通路减轻大鼠气道黏液高分泌北大核心CSCD

目的:探讨槲皮素对LPS诱导的大鼠气道黏液高分泌的作用及其分子机制。方法:将36只SD大鼠随机分为:对照组、LPS组、槲皮素低、中、高剂量组、AG1478组;气道内滴注LPS建立大鼠气道黏液高分泌模型。HE染色观察肺组织的病理变化;AB-PAS染色观察杯状细胞增生和黏液分泌情况;ELISA检测肺组织中MUC5AC浓度;采用免疫组织化学法(IHC)检测MUC5AC、EGFR、PKC、NF-κB表达;RT-qPCR检测肺组织MUC5AC及EGFR mRNA表达;Western blot检测p-EGFR、EGFR、p-PI3K、PI3K、p-PKC、PKC、p-AKT、AKT、NF-κB表达。结果:与LPS组相比,槲皮素低、中、高剂量组病理变化逐渐减轻,肺组织炎症积分和AB-PAS阳性着色面积逐渐降低(P<0.05);槲皮素能减少肺组织MUC5AC、EGFR、PKC、NF-κB表达,降低MUC5AC含量,并下调MUC5AC及EGFR的mRNA水平(P<0.05);槲皮素能减少p-EGFR/EGFR、p-PI3K/PI3K、p-PKC/PKC、p-AKT/AKT、NF-κB蛋白表达(P<0.05)。结论:气管内滴注LPS能成功诱导大鼠气道黏液高分泌模型,槲皮素对LPS诱导大鼠气道黏液高分泌具有拮抗作用,其作用机制可能与抑制EGFR信号通路,调控p-EGFR/EGFR、p-PI3K/PI3K、p-PKC/PKC、p-AKT/AKT、NF-κB表达,下调MUC5AC表达有关。     

α-硫辛酸降低脂多糖诱导的Raw264.7细胞TNF-α的分泌

目的观察α-硫辛酸(ALA)对脂多糖(LPS)在体外诱导的Raw264.7细胞TNF-α释放及机制。方法用ALA或者ALA联合ERK或NF-κB的抑制剂或者激活剂预处理2 h,再用LPS(1 mg/L)体外刺激巨噬细胞Raw264.7;采用MTT法检测ALA对Raw264.7细胞活力影响,利用ELISA方法对Raw264.7释放在培养上清中的细胞因子肿瘤坏死因子(TNF-α)的浓度,及用Western blot方法检测T-p ERK、p ERK和NF-κB的表达。结果 ALA可抑制LPS诱导的Raw264.7细胞TNF-α表达(P0.05),用ALA联合ERK或NF-κB的激活剂预处理后可减弱ALA产生的抑制效果(P0.05)。同时ALA抑制LPS诱导的Raw264.7细胞p ERK和NF-κB的表达(P0.05),用ALA联合ERK或NF-κB的抑制剂预处理后可加强ALA产生的抑制效果(P0.05)。结论 ALA可能通过抑制LPS诱导的Raw264.7细胞的ERK和NF-κB信号通路来抑制TNF-α释放。     

HSP72过度表达对脂多糖刺激的巨噬细胞中NF-κB活性的影响

目的研究过度表达的热休克蛋白72(heat shock protein,HSP72)对脂多糖(lipopolysaccha-ride,LPS)刺激的巨噬细胞中NF-κB活性的影响.方法构建pCD-hsp72重组质粒,转染小鼠巨噬细胞RAW264.7,G418筛选稳定转染hsp72基因的细胞,Western印迹检测转染细胞HSP72的表达水平及LPS刺激后RAW264.7细胞内HSP72的表达水平、LPS刺激后转染细胞中IκBα的含量和胞核中NF-κB的含量的变化.结果构建pCD-hsp72重组质粒并转入巨噬细胞,获得稳定转染hsp72基因的细胞株,LPS刺激细胞内HSP72表达增加;HSP72可通过减少LPS刺激的巨噬细胞中IκBα的降解而抑制NF-κB活性.结论HSP72能抑制LPS激活的巨噬细胞中NF-κB的活化.     

TNF-α与香烟烟雾在诱导气道上皮细胞株黏蛋白表达的相互作用

目的 探讨肿瘤坏死因子TNF-α与香烟提取物共同诱导气道黏液高分泌的相互关系及作用特点。方法 培养的人气道上皮细胞BEAS-2B,转染核转录因子（NF）-κB"decoy"寡核苷酸（ODNs）,并以乱序NF-κB ODNs为对照转染组,各组均分别予以TNF-α、10%香烟提取物（CSE）单独刺激及共同刺激,以Western blot、ELISA及RT-PCR法检测各组刺激前后磷酸化表皮生长因子受体（p-EGFR）、黏蛋白（MUC5AC）蛋白及mRNA水平。结果 转染乱序NF-κB ODNs的细胞予以TNF-α、10% CSE刺激后,各组细胞中p-EGFR蛋白水平较对照组升高,伴随MUC5AC蛋白含量及基因转录水平的提高(P<0.05);共孵育组中较单独刺激组升高更为显著（P<0.05）。转染NF-κB"decoy"ODNs组再予以TNF-α刺激,细胞中MUC5AC蛋白含量及mRNA水平与未转染组相比升高不明显,而单用CSE刺激组中的MUC5AC、p-EGFR水平仍有明显升高（P<0.05）;共孵育组显示出与CSE单独刺激组相似的结果。结论 TNF-α、CSE能协同促进气道上皮细胞中黏蛋白合成,转录因子NF-κB主要参与TNF-α所致的MUC5AC表达,而在CSE诱导的效应过程中作用不明显。     

抑制HMGB1表达促进血管瘤内皮细胞凋亡的机制研究

目的:探讨高迁移率族蛋白B1(HMGB1)对血管瘤内皮细胞(HemECs)活力和凋亡的影响及机制。方法:分离培养人HemECs,将设计并合成的HMGB1小干扰RNA(HMGB1-siRNA)转染HemECs。CCK-8法检测各组细胞活力;流式细胞术检测细胞凋亡率及活性氧(ROS)含量;Western blot检测HMGB1、NF-κB p65、p-IκBα、细胞周期蛋白D1(cyclin D1)和survivin的蛋白表达。结果:与空白对照组比较,转染HMGB1-siRNA的HemECs中HMGB1的蛋白表达显著降低(P0.05)。与NC组比较,转染HMGB1-siRNA的HemECs活力显著降低,凋亡率显著升高,ROS含量显著升高,NF-κB p65、p-IκBα、cyclin D1和survivin的蛋白表达均显著降低(P0.05);且与si-HMGB1组比较,HemECs中加入NF-κB信号通路抑制剂PDTC后,细胞活力抑制、凋亡率和ROS诱导及NF-κB p65、p-IκBα、cyclin D1和survivin的蛋白表达下调更明显(P0.05)。结论:抑制HMGB1表达可降低人HemECs活力和诱导凋亡,机制可能是通过提高ROS含量及下调NF-κB信号通路。     

乙型肝炎病毒X蛋白通过激活ERKs和NF-κB上调大鼠系膜细胞表达TNF-α

目的 探讨乙型肝炎病毒(HBV)X基因转染大鼠系膜细胞肿瘤坏死因子-α(TNF-α)高表达的细胞外蛋白调节激酶(ERKs)、核因子κB(NF-κB)、P38 MAPK信号传导机制.方法 将含有HBV X基因的质粒pCI-neo-X导入体外培养的大鼠系膜细胞,分别采用特异性抑制剂U0126阻断ERK1/2通路,Lactacystin阻断NF-κB通路和SB203580阻断P38 MAPK通路,观察培养细胞TNF-α及其mRNA表达,以不加抑制剂作为对照.RT-PCR检测TNF-α mRNA表达,ELISA检测培养上清液中TNF-α表达.Western blot检测乙型肝炎病毒X蛋白(HBx)表达.结果 转染pCI-neo-X后,系膜细胞TNF-α mRNA及上清液TNF-α表达均增高,通过阻断ERK1/2或NF-κB通路,细胞TNF-α mRNA及上清液TNF-α表达均下降.而阻断P38 MAPK通路对系膜细胞TNF-α mRNA及上清液TNF-α表达无明显影响.结论 HBx蛋白通过激活ERKs和NF-κB信号通路使系膜细胞高表达TNF-α,而与P38 MAPK通路无关.     

β-胡萝卜素对脂多糖刺激巨噬细胞RAW264.7炎症因子的影响及其机制

目的:探讨β-胡萝卜素对脂多糖(LPS)刺激巨噬细胞RAW264.7炎症因子的影响及其机制。方法:采用5μg/ml的LPS刺激巨噬细胞24 h后用不同浓度的β-胡萝卜素(20、40、80、160μmol/L)处理细胞3 h,MTT法测细胞活性,荧光定量PCR测炎症因子IL-1β、IL-6、TNF-αmRNA相对表达量,ELISA测炎症因子IL-1β、IL-6、TNF-α的分泌量,Western blot测NF-κB p65蛋白相对表达量。5μg/ml的LPS和不同浓度的NF-κB抑制剂PDTC(1、5、10μg/ml)共同处理巨噬细胞24 h,Western blot测NF-κB p65蛋白相对表达量,荧光定量PCR、ELISA测炎症因子的表达和分泌。比较LPS+PDTC组和LPS+PDTC+β-胡萝卜素组炎症因子和NF-κB p65蛋白相对表达的变化。结果:与LPS组相比,不同浓度的β-胡萝卜素对LPS刺激的巨噬细胞的细胞活性有提升作用,对炎症因子和NF-κB p65蛋白的表达有抑制作用;抑制NF-κB蛋白的表达可以抑制LPS刺激的巨噬细胞炎症因子的分泌;LPS+PDTC+β-胡萝卜素组对炎症因子的抑制作用比LPS+PDTC组明显,且差异显著(P0.05),但两组对NF-κB p65蛋白的表达不明显。结论:β-胡萝卜素可以通过抑制NF-κB通路中NF-κB p65蛋白的表达抑制LPS刺激的巨噬细胞炎症因子IL-1β、IL-6、TNF-α的分泌,且此通路不是唯一相关的通路。     

RAS蛋白在胶质瘤中的表达及其对胶质瘤细胞生长的影响

目的 探讨RAS蛋白在胶质瘤中的表达及其对人脑胶质瘤细胞生长的影响.方法 用免疫组化染色法检测RAS蛋白在正常脑组织及各级别胶质瘤组织中的表达水平,并采用四甲基偶氮唑盐微量酶反应比色法和流式细胞技术检测降低RAS活性后U251细胞的增殖和凋亡情况;用Western印迹法检测ERK和AKT信号通路.结果 胶质瘤组织中RAS的表达随胶质瘤恶性程度增高而增强.抑制RAS 蛋白活性后,RAS信号通路的下游分子ERK和AKT蛋白磷酸化水平降低;U251胶质瘤细胞生长受抑制,细胞生长阻滞在G1期且凋亡增加.结论 RAS蛋白在胶质瘤中高表达,抑制其活性可下调ERK和AKT 信号通路,进而调控细胞的生长.     

Isolation of human C-reactive protein and serum amyloid P component

Procedures are described for the isolation in high yield of consistent, highly purified preparations of human C-reactive protein (CRP) and serum amyloid P component (SAP). CRP was obtained from malignant ascitic and pleural fluids by calcium-dependent affinity chromatography on pneumococcal C-polysaccharide covalently coupled to cyanogen bromide-activated Sepharose. It was then gel filtered on Ultrogel AcA44 (acrylamideagarose beads) in the presence of calcium ions, combining molecular sieve chromatography with removal of contaminating SAP by its affinity for agarose. Residual trace contaminants were removed by immunoabsorption with anti-normal human serum and anti-SAP antibodies insolubilised on Sepharose and/or by absorption with Sepharose-Con A to remove glycoproteins and Blue-Sepharose to remove albumin. After a final gel filtration step on Sephacryl S-300 35–44% of the initial CRP was recovered in pure from according to biochemical and immunochemical criteria. SAP was isolated from normal serum by calcium-dependent affinity chromatography on unsubstituted Sepharose beads, followed by solid-phase immunoabsorption of contaminants and finally gel filtration on Sephacryl S-300. At least 50% of the SAP in the starting material was recovered in pure form according to biochemical and immuunochemical criteria. Ready availability of such preparations facilitates biochemical, biophysical and particularly biological studies of these plasma proteins.     

The concentration of the C-type lectin, mannan-binding protein, in human plasma increases during an acute phase response.

Two ELISAs for estimating mannan-binding protein (MBP) were constructed and the concentration of MBP in plasma was followed in patients undergoing major surgery and in patients having a malarial attack. In both cases increases of MBP in the plasma were observed. The relative increase and the kinetics varied from person to person. The concentration of MBP increased between 1.5- and three-fold following surgery. In some patients an increase was seen at day 1 whereas in others the increase was not observed until days 3-9. In the malaria patients an increased level of MBP was maintained during 30 days of treatment with chloroquine. The relative increase in MBP was independent of the presurgery or premalaria levels.     

Binding of mannan-binding protein to various bacterial pathogens of meningitis

Mannan-binding protein (MBP), a calcium-dependent plasma lectin, may play a role in the innate defence against microorganisms. After binding lo carbohydrate structures at the bacterial surface, MBP activates the classical pathway of the complement system. To investigate the binding capacity of MBP to various bacteria associated with meningitis, an assay was developed to study the binding of MBP to bacteria grown in a semisynthetic fluid culture medium. Salmonella montevideo (containing a mannose-rich lipopolysaccharide (EPS)), used as a positive control strain, showed binding of radiolabelled MBP at a level of 80% compared with binding of MBP to zymosan. Binding of labelled MBP to Salm. montevideo was time-dependent, temperature-dependent and saturable. The binding, was inhibited by unlabelled MBP., by mannose and by N-acetyl-o-glucosamine. Among bacterial pathogens often found to cause meningitis, a wide range of MBP binding capacities could be determined. The encapsulated Neisseria meningitidis (representatives from 11 serogroups other than group A were included: n = 22), N. mucosa (n = 1), Haemophilus influenzae type b (n = 10) and Streptococcus agalactiae (n = 5) had a low MBP binding capacity of 21.7% (95% confidence interval (Cl) 3.3–40.1%). Escherichia coli K1 (n =11). Strep, suis (n = 5), Strep, pneumoniae (n = 10) and N. meningitidis scrogroup A (n = 2) showed intermediate MBP binding capacity of 58.4% (95% Cl 40.0–76.8%). A third group consisting of non-encapsulated Listeria monocytogenes (n = 11), non-encapsulated H. influenzae (n = 2), non-encapsulated N. meningitidis (n = 2), N. cinera (n = 1) and N. subflava (n = 1) strains had a high MBP binding capacity of 87.5% (95% CI 62.5–12.5%). The majority of encapsulated pathogens causing bacterial meningitis seem to have a rather low MBP binding capacity.     

β淀粉样蛋白对大鼠学习记忆功能及tau蛋白异常磷酸化的影响

为了探讨β淀粉样蛋白对大鼠学习记忆功能和tau蛋白异常磷酸化的影响,本文在海马注射Aβ25-35建立阿尔茨海黙病(AD)大鼠模型的基础上,通过行为学检测、HE染色、免疫组化和免疫蛋白印迹技术对动物的学习能力、组织的病理改变和tau(pS202)、tau(pT231)和tau-5的表达情况进行了分析。在行为学检测中,Aβ注射组大鼠在穿梭箱实验中的主动回避次数和被动回避次数减少,失败次数增多,而在Morris水迷宫测试中的逃避潜伏期和游泳距离延长。HE染色显示Aβ注射组大鼠海马CA1、CA3、齿状回的神经细胞数目减少;而免疫组化和免疫印迹结果显示注射组tau(pS202)阳性细胞明显增加,tau(pS202)、tau(pT231)和tau-5蛋白表达增加。以上结果提示海马内注射Aβ25-35可引起大鼠学习记忆功能下降,可能与神经细胞减少,tau蛋白异常磷酸化增多有关。     

上皮钙黏蛋白、波形蛋白和Snail蛋白表型在乳腺浸润性导管癌中表达的相关性及其与预后的关系

目的 检测上皮钙黏蛋白(E-cadherin)、波形蛋白(Vimentin)和Snail蛋白在乳腺浸润性导管癌中的表达情况与乳腺癌病理特征的关系及其与浸润性导管癌预后的关系.方法 采用Envision免疫组织化学方法对89例乳腺浸润性导管癌组织中的上E-cadhenn,Vimentin和Snail蛋白表达情况进行检测并分析表达程度与临床病理特征之间的关系;统计分析采用卡方检验、Fisher精确概率法检验Spearman等级相关检验、配对计数资料检验、Kaplan-Meier法进行单因素生存分析,Cox比例风险模型进行生存的多因素分析.结果 E-cadherin、Vimentin和Snail蛋白在浸润性导管癌组织中的阳性表达率分别为、47.1％、53.9％和55.0％,三者呈负相关,(P=0.003);E-cadherin、Vimentin和Snail蛋白的表达与临床TNM分期有关(P ＜0.005).浸润性导管癌中Snail蛋白、Vimentin表达明显增高,Snail蛋白与淋巴结转移有关(P =0.029);Vimentin与淋巴结转移、雌激素状态有关(P =0.006,P＜0.001);E-cadherin表达明显降低,与孕激素状态有关(P =0.030);分子分型结果显示,管腔A型、HER-2阳性型组的Vimentin、Snail蛋白阳性表达率低于基地细胞样型组(P =0.012),而E-cadherin表达率则高于基地细胞样型组(P =0.004).Cox分析发现,E-cadherin低表达和Vimentin的过度表达与患者总生存期(P =0.019、P=0.045)及患者无病生存期(P =0.032、P=0.024)显著相关,但Snail蛋白的表达与总生存期及无病生存期无相关性(P =0.879、P=0.835).结论 E-cadhern、Vimentin和Snail蛋白在乳腺浸润性导管癌的发生、发展、侵袭及转移中起重要作用,对认识乳腺癌的生物学特性以及对指导乳腺癌的诊疗及预后具有重要意义.     

Lack of binding between cryoimmunoglobulins, immunoglobulins and fibronectin: implications for immune complex vasculitis

Immune-complex-mediated vasculitis is a frequent complication of rheumatoid arthritis and systemic lupus erythematosus. The mechanism of deposition of immune complexes within the vessel wall in these diseases remains unknown, but probably involves other proteins. Fibronectin is a likely candidate since it possesses the ability to bind to collagen, endothelial cells, and possibly immunoglobulins and immune complexes. In this study, the binding of fibronectin to IgG and IgM cryoglobulins, cold soluble IgM, IgG, IgG subclasses and IgG fragments was investigated in the solution phase. Static light scattering, fluorescence anisotropy, fluorescence intensity, and PEG precipitation studies were used to investigate binding under different conditions of temperature and ionic strength. These studies failed to demonstrate significant binding between fibronectin and IgM, IgG, IgG subclasses and IgG fragments under the conditions studied. These findings argue against solution phase binding of fibronectin and immunoglobulins contributing to immune complex vasculitis. The possibility of important surface interactions between these proteins has not been ruled out.     

La蛋白质家族与肿瘤关系

La蛋白相关家族(La-related proteins,LARPs)包括LARP1、LARP1b、LARP3,(Genuine La)、LARP4a、LARP4b、LARP6和LARP7.LARPs结构包含中度保守的RNA识别模体(RNA recognition motif,RRM)和多个其他结构、运输元件,可定位于不同的亚细胞部位与RNA相互作用,在细胞转录和翻译等方面发挥重要的作用.人LARPs最初是在系统性红斑狼疮和Sjogren's综合征患者的血清内发现的自体抗原,目前随着研究深入普遍认为LARPs作为一种RNA分子伴侣参与RNA代谢能发挥多种生物学功能.此前国内有学者研究验证LARPs能稳定乙型肝炎病毒(hepatitis B virus,HBV)的mRNA,帮助其在肝细胞中复制与翻译,在乙型肝炎进展中具有重要作用.近年发现,LARPs在多种恶性肿瘤如子宫颈癌、乳腺癌、肝癌和前列腺癌等的细胞增殖、分化、迁移、血管形成的调节等方面起重要作用.而恶性肿瘤的发生与演进是由环境与遗传因素相互作用而导致的许多基因突变,实际上基因突变产生的编码蛋白质执行细胞生命活动,因而LARPs在肿瘤中扮演的分子角色将可能在肿瘤的诊断与治疗中提供潜在的新靶点、新策略和新途径.     

Eosinophil cationic protein and eosinophil protein X in the nasal lavage of children during the first 4 weeks of life. SPACE Collaborative Study Team

Eosinophil cationic protein (ECP) and eosinophil protein X (EPX) are well established as markers of eosinophil activation. We analyzed ECP and EPX concentrations in nasal lavage fluids (NALF) of 378 neonates during their first 4 weeks of life. Inclusion criteria were a positive history of parental allergy and a positive skin prick test or specific IgE (RAST class > or = 2) against at least one out of a panel of common aeroallergens in one or both parents. Twenty-four infants with no history of parental allergy were used as controls. A volume of 2 ml of 0.9% saline was instilled into each nostril and immediately recovered by a suction device. ECP and EPX were analyzed by radioimmunoassay. In 65 samples of three consecutive lavages, EPX was detected in nine samples (13.8%) in the control group, whereas it was detected in 197/360 samples (54.7%) in the study population. The corresponding figures for ECP were 17/65 (26.2%) in the control group and 173/365 (47.4%) in the study group. Both proteins showed a skewed distribution (median/5-95th percentiles for ECP: 0 microg/l [0-69.4] and EPX: 6.6 microg/l [0-73.2]). The differences between the control group and the study group were statistically significant, regardless of the allergic disease of the parents. In children of allergic parents, activation proteins of the eosinophil granulocyte are released on the nasal mucosal surface in about 50% of the studied population at the age of 4 weeks. This early onset of eosinophil activation in the nasal respiratory epithelium may reflect a genetic predisposition to allergy or early exposure to allergens.