较大潮气量机械通气致幼兔肺生物伤中NF-kB的作用及对致炎细胞因子的影响

目的 探讨NF-kB在幼兔较大潮气量机械通气致肺生物伤中的作用以及对肿瘤坏死因子α（TNF-α）和白细胞介素8（IL-8）的影响。方法27只普通级幼兔随机等分为3组，（1）对照组（NMV，n=9）：不进行机械通气；（2）常规机械通气组CMV（CMV，n=9）：潮气量（VT）=8mVkg；（3）大潮气量机械通气组（LMV，n=9）：V，=24ml／kg。采用凝胶电泳迁移率改变分析法（EMSA）检测各时相点肺组织核蛋白提取物中NF-kB活性，Western Blot法测定肺组织IkBα含量，同时应用RT-PCR和ELISA法检测肺组织匀浆中TNF-α和IL-8 mRNA表达及其蛋白含量，并观察肺组织病理改变。结果在各时相点LMV的NF-kB活性明显高于NMV和CMV（P〈0．01）；CMV的NF-kB活性则高于NMV（P〈0．01）。IKBQ含量在LMV随通气时间延长呈进行性降低，与NMV和CMV比较有显著性差异（P〈0．01）。机械通气后LMV的TNF-α和IL-8含量及表达较CMV、NMV明显增高（P〈0．01），TNF-α表达及含量在通气后4h达高峰，6h明显降低，而继TNF-α达峰后，IL-8在通气后6h达最高。肺组织病理学显示，随通气时间延长，LMV的肺泡结构破坏，肺泡壁和肺间质内有大量中性粒细胞浸润和较多红细胞渗出。CMV的肺间质及肺泡壁轻度水肿、有少量粒细胞浸润。NMV未见病理性改变。结论在损害性机械通气肺损伤的发生过程中，IkBα降解和NF-kB活化可能参与了肺组织致炎细胞因子基因表达的调控过程。     

较大潮气量机械通气致幼兔肺生物伤中NF-κB的作用及对致炎细胞因子的影响

目的探讨NF-κB在幼兔较大潮气量机械通气致肺生物伤中的作用以及对肿瘤坏死因子α(TNF-α)和白细胞介素8(IL-8)的影响。方法27只普通级幼兔随机等分为3组,(1)对照组(NMV,n=9):不进行机械通气;(2)常规机械通气组CMV(CMV,n=9):潮气量(VT)=8ml/kg;(3)大潮气量机械通气组(LMV,n=9):VT=24ml/kg。采用凝胶电泳迁移率改变分析法(EMSA)检测各时相点肺组织核蛋白提取物中NF-κB活性,WesternBlot法测定肺组织IκBα含量,同时应用RT-PCR和ELISA法检测肺组织匀浆中TNF-α和IL-8mRNA表达及其蛋白含量,并观察肺组织病理改变。结果在各时相点LMV的NF-κB活性明显高于NMV和CMV(P<0·01);CMV的NF-κB活性则高于NMV(P<0·01)。IκBα含量在LMV随通气时间延长呈进行性降低,与NMV和CMV比较有显著性差异(P<0·01)。机械通气后LMV的TNF-α和IL-8含量及表达较CMV、NMV明显增高(P<0·01),TNF-α表达及含量在通气后4h达高峰,6h明显降低,而继TNF-α达峰后,IL-8在通气后6h达最高。肺组织病理学显示,随通气时间延长,LMV的肺泡结构破坏,肺泡壁和肺间质内有大量中性粒细胞浸润和较多红细胞渗出。CMV的肺间质及肺泡壁轻度水肿、有少量粒细胞浸润。NMV未见病理性改变。结论在损害性机械通气肺损伤的发生过程中,IκBα降解和NF-kB活化可能参与了肺组织致炎细胞因子基因表达的调控过程。     

不同潮气量通气启动新生鼠肺纤维化的特点

目的：探讨不同潮气量机械通气后新生大鼠肺胶原合成的变化及其机制。方法：24只新生Sprague-Dawley大鼠随机分为对照组、常规通气组（潮气量10 mL/kg）及过度通气组（潮气量25 mL/kg）,每组8只。机械通气5 h后处死,取肺组织,左肺行肺组织病理损伤评分,以免疫组织化学方法观察结缔组织生长因子（CTGF）表达。PCR法检测右肺组织Ⅲ型前胶原蛋白mRNA（PcolⅢ mRNA）、半胱氨酰白三烯mRNA（CysLT1 mRNA）及CTGF mRNA水平。结果：肺损伤程度和纤维化程度随着潮气量增加而增加(P<0.05）。与对照组比较,过度通气组肺组织CTGF mRNA水平显著性增高（P<0.05）。肺组织PcolⅢ mRNA 和 CysLT1 mRNA水平随潮气量增加而增加,各组间差异有统计学意义（P<0.05）。肺组织中PcolⅢ mRNA表达与肺组织病理损伤程度呈正相关关系（r=0.78,P<0.01）;CTGF、CysLT均和PcolⅢ呈正相关关系(r＝0.59,0.86,P<0.01)。结论：不同潮气量机械通气导致不同程度肺损伤,并启动肺纤维化。肺纤维化程度与肺损伤程度一致。肺纤维化的启动与CysLT作用和CTGF激活有关。［中国当代儿科杂志,2010,12（10）：799-803］     

Toll样受体信号与新生儿脓毒症炎症反应机制初探

目的 探讨Toll样受体(Toll-like receptors,TLRs)及其信号传递分子在新生儿脓毒症炎症免疫反应中的作用.方法 新生儿脓毒症20例,正常新生儿对照组16例,抽取各组新生儿静脉血3ml备检,未加任何体外丝裂原刺激培养.采用适时荧光定量PCR检测外周血单个核细胞TLR1～TLR10、髓样分化蛋白2(myeloid differentiation protein 2,MD-2)、髓样分化因子88(myeloid differentiation factor 88,MyD88)、白细胞介素(interleukin,IL)-1β、IL-6、IL-8、肿瘤坏死因子(tumor necrosis factor,TNF)-α mRNA的表达;酶联免疫吸附试验检测IL-1β、IL-6、IL-8、TNF-α等前炎症因子蛋白表达.结果 (1)新生儿脓毒症组TLR2、TLR4 mRNA表达均显著高于正常对照组(TLR2:55.16±12.78 vs 9.53±3.73,P＜0.01;TLR4:125.22±30.64 vs 23.17±5.78,P＜0.01),其他TLRs表达无明显改变;(2)新生儿脓毒症组TLR4信号传递分子MD-2及MyD88明显增高(MD-2:376.83±62.16 vs 12.92±2.54,P＜0.01;MyD88:11.97±2.48 vs 2.77±0.59,P＜0.01);(3)新生儿脓毒症组前炎症细胞因子IL-1β、IL-6、IL-8、TNF-α表达明显增高[PCR:(IL-1β:21.72±5.56 vs 5.69±1.26,P＜0.01;IL-6:71.39±18.34 vs 9.65±2.13,P＜0.01;IL-8:29.39±6.72 vs 8.72±1.95,P＜0.01;TNF-α:65.42±16.95 vs 12.33±3.45,P＜0.01)],[ELISA:(IL-1β:2 977.36±653.97 vs 480.52±120.36,P＜0.01;IL-6:3 143.82±775.08 vs 393.78±96.55,P＜0.01;IL-8:2 510.78±686.77 vs 276.91±72.46,P＜0.01;TNF-α:3 582.24±876.13 vs 1 233.68±289.39,P＜0.01)].结论 新生儿脓毒症TLRs信号途径异常活化,前炎症细胞因子表达明显增高,提示新生儿天然免疫已具初步的抗感染免疫反应能力,TLRs异常活化可能是新生儿脓毒症免疫功能紊乱的始动因素.     

肺复张策略救治急性肺损伤幼猪的实验研究

目的：通过急性肺损伤（ALI）幼猪模型,研究肺复张策略（RM）的可行性和有效性,并探讨其对损伤后肺组织修复的影响。方法：健康幼猪12只,注射内毒素（LPS）成模后,随机分为常规潮气量通气组（CON组）和小潮气量联合RM通气组（RM组）,观察8 h,动态监测血液动力学、肺动态顺应性及血气分析指标,测定血浆、肺泡灌洗液中转化生长因子（TGF-β1）浓度,实时荧光定量PCR法检测TGF-β1在肺组织中的mRNA表达水平,并观察肺组织的病理学改变。结果：两组幼猪的心输出量和外周血管阻力指标差异无统计学意义;而RM组的血管外肺水指数在成模6 h以后,肺血管通透性指数于成模8 h时均较CON组明显下降（P＜0.05）;RM组的肺动态顺应性明显高于同时间点的CON组（P＜0.05）;RM组PaO2/FiO2值于成模2 h后明显高于CON组,而且RM组的肺泡-动脉氧分压差在成模2 h后即明显下降（P＜0.05）;RM组血浆、肺泡灌洗液中TGF-β1浓度及其在肺组织中的mRNA表达水平均低于相应CON组;RM组的肺泡扩张度明显高于CON组,而肺损伤评分明显下降（P＜0.05）。结论：RM可以改善ALI幼猪的气体交换和肺动态顺应性,且安全有效,能够扩张肺泡并减轻肺损伤程度,有助于改善损伤后的肺修复过程。     

吸入一氧化氮对早产猪未成熟肺的作用

目的：研究早产猪在机械通气下吸入一氧化氮(NO)对未成熟肺的呼吸功能、核转录因子(NFκB)表达的影响,以研究出生早期吸入NO是否对不成熟肺产生不良反应,并判断应用肺表面活性物质(PS)及NO的肺保护作用效果及其调节炎症反应的作用和机制。方法：选择101～103d孕龄(89%足月孕期)母猪,行剖宫产获得32头早产猪(平均出生体重870g),气管插管后行间歇正压机械通气,随机分成4组(每组n=8)治疗:单纯机械通气(C组);吸入NO(NO组);加用肺表面活性物质(PS组);NO和PS联合应用(SNO组)。另选同窝自主呼吸组(N组)用于比较NFκB水平、肺湿干重比及肺组织病理学。机械通气各组分别测肺功能,血气分析,计算氧合指数(OI)和通气指数(VI)。机械通气6h后处死动物。结果：治疗6h肺顺应性(Cdyn)和气道阻力(Raw)在各组间无统计学差异,OI在SNO组显著低于C组2.3±1.9vs9.5±7.5(P<0.05),VI在NO和SNO组低于C组和PS组(P<0.05或P<0.01)。NO组及N组NFκB活性最低,与C组相比差异有显著性,P<0.05。NO吸入过程中监测NO2水平均<1ppm。所有动物高铁血红蛋白(MetHb)浓度均<4%。NO和SNO组肺组织湿干重比显著低于C组6.88±0.53vs7.77±0.76(P<0.05)和6.61±0.56vs7.77±0.76(P<0.01)。病理检查见各组不同程度肺水肿、白细胞浸润,肺泡扩张度(Vv)和变异度(CV[Vv])显示肺泡中度成熟,但差异均无显著性。结论：出生早期应用iNO或联合应用PS治疗可改善早产猪氧合和机械通气效率;小剂量短时间NO吸入有利于肺液清除,没有显著改变PS成分和/或直接致肺损伤;NO通过下调NFκB可能具有抑制/调节早产肺炎症反应启动机制的作用。     

黄褐毛忍冬总皂苷对卵清蛋白致敏小鼠肠道炎症因子和抗炎因子的影响

目的 观察黄褐毛忍冬总皂苷(Ful)对卵清蛋白(OVA)致敏小鼠肠道炎症因子和抗炎因子的影响.方法 24只雌性BALB/c小鼠随机取16只,采用卵清蛋白致敏和激发构建食物过敏模型,均分为2组,即食物过敏组(FA组)和Ful干预组(Ful组).Ful组小鼠自造模第20天起每日皮下注射Ful 200 mg/kg,共22 d.另8只小鼠作为正常对照组(NS组).采用逆转录-聚合酶链反应(RT-PCR)法检测小鼠空肠组织中转化生长因子β1(TGF-β1)、白细胞介素6(IL-6)、白细胞介素17A(IL-17A)、叉头蛋白3-T细胞转录因子(Foxp3)mRNA表达;免疫组织化学法检测小鼠空肠组织中TGF-β1、IL-6、IL-17A蛋白表达;检测空肠中髓过氧化物酶(MPO)活性代表中性粒细胞活化水平.结果 FA组小鼠空肠组织中TGF-β1、IL-6、IL-17A的mRNA[(0.370±0.013)、(0.475±0.015)]和TGF-β1、IL-6、IL-17A蛋白表达水平[(53 075.70±20 727.06)、(256 881.66±36 561.79)、(435 064.25±69 911.48)]均增高,Foxp3 mRNA(0.231±0.014).经黄褐毛忍冬总皂苷干预后,小鼠空肠组织TGF-β1表达未下降,但IL-6、IL-17A的mRNA[(0.196±0.005)、(0.204±0.008)]和蛋白表达水平[(114 040.30±20 295.25)、(218 200.74±30 077.69)]均明显降低,而Foxp3 mRNA(0.578±0.021)表达明显增高.空肠组织中MPO水平各组间比较差异无统计学意义(P＞0.05)..结论 食物过敏发生时肠道内存在以IL-6、IL-17A表达增高为主的炎症反应.Ful可有效降低OVA致敏小鼠肠道炎症因子IL-6、IL-17A的过度表达,显著增强调节性T细胞特异性转录因子Foxp3的表达,从改善OVA诱导的肠道炎症.     

红霉素对高氧暴露早产鼠肺组织肿瘤坏死因子-α和白细胞介素-8的干预作用

目的 观察大环内酯类抗生素红霉素对高氧暴露下早产新生大鼠肺组织肿瘤坏死因子(tumor necrosis factor,TNF)-α和白细胞介素(interleukin,IL)-8表达的影响,探讨红霉素对高氧肺损伤的干预作用.方法 早产新生SD大鼠生后ld按随机数字表法随机分为4组:空气暴露+生理盐水组、空气暴露+红霉素组、高氧暴露+生理盐水组及高氧暴露+红霉素组.空气暴露组置于同一室常压空气中;高氧暴露组持续暴露于常压氧舱中,氧浓度＞85％.4组早产鼠分别于空气或高浓度氧暴露后1、7、14d提取肺组织标本.采用石蜡包埋切片行苏木精-伊红染色观察肺组织的病理学变化.采取ELISA法分析血清细胞因子TNF-α和IL-8的水平.结果 (1)与空气暴露+生理盐水组比较,高氧暴露1、7d,高氧暴露+生理盐水组早产鼠肺组织TNF-α和IL-8表达水平显著增强[1 d:TNF-α:(16.163±0.574) ng/ml vs.(21.923±2.066) ng/ml,IL-8:(18.214±3.649) ng/ml vs.(23.546±5.240) ng/ml;7 d:TNF-α:(15.940±0.821) ng/ml vs.(19.688±0.764) ng/ml,IL-8:(18.541±4.114) ng/ml vs.(24.255±4.692) ng/ml],尤其TNF-α表达增强出现更早,14 d明显减弱(P＜0.05).(2)与高氧暴露+生理盐水组比较,红霉素干预后l、7、14d,高氧暴露+红霉素组早产鼠肺组织中TNF-α和IL-8表达水平显著降低(P＜0.05)[1 d:TNF-α:(21.923±2.066) ng/ml vs.(18.903±1.851) ng/ml,7 d:IL-8:(24.255±4.692) ng/ml vs.(23.508±3.543) ng/ml,14 d:TNF-α:(16.443±5.466) ng/ml vs.(14.453±0.963) ng/ml],但相对于1、7d时,14d降低程度轻.结论 氧化爆发诱导的炎症介质TNF-α和IL-8释放参与高氧肺损伤的发生发展过程,红霉素可能通过机体免疫调节作用,抑制炎症介质释放,在减轻高氧肺损伤过程中发挥重要作用.     

谷氨酰胺影响脓毒症大鼠脑内PDGF及其受体表达的研究

目的：该研究旨在探讨脓毒症幼年大鼠大脑血小板衍生生长因子-B（PDGFB）及其受体(PDGFR-β)表达的变化及谷氨酰胺（Gln）干预的影响,探讨PDGF-B在幼年期脓毒症时脑损伤发病机制中的作用及Gln对脑损伤的可能保护机制。方法：120只10日龄Wistar大鼠随机分为对照组、内毒素组（LPS）和谷氨酰胺组（Gln）。腹腔注射内毒素（LPS,5 mg/kg)制备幼年大鼠脓毒症动物模型。Gln组为腹腔注射LPS前1 h腹腔注射Gln (1.346 g/kg)。各组大鼠又分为5个亚组（n=8）,分别于注射后2、6、12、24及72 h处死,采用免疫组织化学方法及免疫印迹法检测大脑皮层PDGF-B及PDGFR-β的表达。结果：（1）免疫组织化学方法结果显示注射LPS后 72 h Gln组大脑皮层神经元PDGF-B和 PDGFR-β表达明显高于对照组和LPS组。（2）免疫印迹方法结果显示,LPS组和Gln组于注射LPS后第2 h、6 h和12 h 的PDGF-B表达均低于对照组（P＜0.05）。而Gln组12 h和72 h 的PDGF-B表达明显高于LPS组（P＜0.05）。与对照组比较,LPS组大脑组织PDGFR-β表达在2 h和6 h增加,而在72 h表达下降（P＜0.05）。Gln组则与对照组于各时间点比较,差异均无统计学意义。结论：Gln在注射LPS后能上调大脑PDGF-B和PDGFR-β的表达,提示Gln对幼年期脓毒症脑损伤的保护机制可能与其促进大脑PDGF-B和PDGFR-β的表达有关。［中国当代儿科杂志,2010,12(12)：967-971］     

高体积分数氧暴露早产大鼠肺组织血红素加氧酶-1的表达及活性变化

目的 观察血红素加氧酶-1(HO-1)在高体积分数氧(高氧)暴露早产大鼠肺组织中的表达及活性变化,探讨HO-1在早产大鼠高氧肺损伤中的作用.方法 将3日龄早产SD大鼠28只随机分为高氧组、空气组(每组14只),于实验第3、7天分别用半定量反转录-聚合酶链反应法和免疫组织化学法检测各组早产大鼠肺组织HO-1 mRNA表达水平和HO-1蛋白在肺组织的分布和表达水平,并测定HO-1的活性.采用SPSS 12.0软件进行统计学分析.结果 实验第3天,空气组早产大鼠肺组织HO-1 mRNA(0.17±0.08)、HO-1蛋白(7.23±4.63)均有微弱表达,HO-1活性为(4.32±1.57)nmol/(mg·h);高氧组早产大鼠肺组织HO-1mRNA(0.72±0.33)表达明显高于空气组(Pa<0.01),HO-1蛋白(18.54±6.55)仅在臣噬细胞表达弱阳性,HO-1活性明显增加(6.14±1.62)nmol/(mg·h),二者均明显高于空气组(Pa<0.05).实验第7天,各组早产大鼠肺组织HO-1 mRNA均未见表达,高氧组早产大鼠肺组织HO-1蛋白表达及活性均显著高于空气组[(51.24±18.32)vs(4.11±1.82),(32.38±5.46)nmol/(mg·h)vs(5.75±1.87)nmol/(mg·h) Pa<0.01].结论 HO-1可能参与了早产大鼠高氧肺损伤的过程.     

Effects of positive end-expiratory pressure, inhaled nitric oxide and surfactant on expression of proinflammatory cytokines and growth factors in preterm piglet lungs

We hypothesized that imbalance of proinflammatory cytokines and growth factors (GFs) in immature lungs of early postnatal life may be affected by protective ventilation strategy, and evaluated correlations of these aspects. Preterm neonate piglets were mechanically ventilated with low tidal volume and 5-6 or 10-12 cm H2O positive end-expiratory pressure (PEEP) with or without surfactant and inhaled nitric oxide (iNO) for 6 h, followed by biochemical, biophysical, and histopathological assessment of lung injury severity. Compared with surfactant and the control, iNO combined with lower PEEP exerted better oxygenation, lower activity of myeloperoxidase, lower expression of mRNA of interleukin (IL)-1beta, IL-6, IL-8, and platelet derived growth factor-B (PDGF-B), but higher expression of insulin-like growth factor-I (IGF-I), whereas that of tumor necrosis factor-alpha, keratinocyte GF, hepatocyte GF, vascular endothelial growth factor, and TGF-beta1 had no or modest changes. IL-1beta, IL-6 mRNA were closely correlated to PDGF-B mRNA and myeloperoxidase, but inversely to IGF-I mRNA, Pao2/FiO2 and dynamic lung compliance at 6 h. These results indicate that the association of lower PEEP and iNO may be more protective than surfactant on preventing lung injury and facilitating reparation by affecting the expression of proinflammatory cytokines and GFs.     

Enhanced interleukin-6 and interleukin-8 synthesis in term and preterm infants

There is growing evidence that sepsis-related complications in neonates are crucially mediated by the action of proinflammatory cytokines. It has previously been demonstrated that elevated IL-6 and IL-8 levels can predict brain damage and chronic lung disease in preterm infants. However, it is the current view that neonates have a reduced capability to produce proinflammatory cytokines. To clarify this issue, we analyzed the inflammatory response in term and preterm infants directly at the single cell level by flow cytometry. Endotoxin challenge was performed under defined conditions on monocytes obtained from 50 healthy adults and 119 neonates, which consist of 45 term infants, 63 preterm infants (26.1-36.7 wk of gestational age), and 11 preterm infants with proven infection (24.6-29.9 wk). Our results challenge the existing view of an immature inflammatory response by demonstrating that term infants and preterm infants display a higher percentage of IL-6- and IL-8-positive cells than adults. After preincubation with dexamethasone the number of cytokine-positive cells decreased in all groups, but the number of IL-8-positive cells remained higher in term and preterm infants >32 wk compared with adults. These observations demonstrate not only a well-developed but also an enhanced inflammatory response in term and preterm infants. Under consideration of several detrimental effects of IL-6 and IL-8, our data may have major implications on the pathophysiology of inflammatory-triggered neonatal diseases.     

Inflammatory and growth mediators in growing preterm infants

Little is understood about the optimal balance between IGF-I and antagonistic inflammatory mediators, such as IL-6, in growing preterm infants. Using a prospective cohort study, we investigated the relationship between postnatal growth of preterm infants and key growth and inflammatory mediators. We studied 51 stable, growing preterm infants (mean gestational age: 27.8 +/- 0.4 weeks, mean birth weight: 1,032.8 +/- 50.6 g). IL-6 and IL-1ra (reflecting stress/ inflammation) and IGF-I and GHBP (reflecting anabolic activity and GH sensitivity) were measured at enrollment and discharge using ELISA. During the observation period (mean 6.1 +/- 0.34 weeks) there was a significant increase in weight (1,396 +/- 81 g, p < 0.0001). IGF-I increased from 46.6 +/- 4.1 to 88.7 +/- 5.2 ng/ml (p < 0.001). In contrast, IL-6 decreased from 9.5 +/- 1.0 to 2.3 +/- 0.34 pg/ml (p <0.001) and IL-1ra from 6,042 +/- 362 to 4,851 +/- 365 ng/ml (p = 0.007). GHBP increased from 65.8 +/- 6.7 to 82.5 +/- 7.9 ng/ml (p = 0.003). IL-6 was inversely correlated with IGF-I (p < 0.001). In addition, a multiple regression model showed IGF-I levels correlated positively and IL-6 levels inversely with various parameters of growth. Growth in preterm infants is characterized by increases in IGF-I and GHBP with simultaneous decreases in IL-6 and IL-1ra. Efforts to optimally balance inflammatory and growth mediators may benefit somatic growth in infants very early in life.     

CD14 receptor expression and lipopolysaccharide-induced cytokine production in preterm and term neonates

CD14 expression and the capacity of mononuclear cells (MC) from preterm and term neonates to secrete the proinflammatory cytokines interleukin (IL) 1 beta, tumor necrosis factor alpha and IL-6 in response to lipopolysaccharide (LPS) was investigated and compared to that of adults. MC were incubated with various doses of LPS, and the cytokine level in the supernatants was tested. CD14 receptors on MC and the intensity of their expression were analyzed. MC of preterm and term neonates and adults responded to LPS with low, medium and high proinflammatory cytokine production, respectively. CD14 expression was lowest in preterm infants, intermediate in term infants and highest in adults. The difference between term and preterm neonates for both parameters was significant. The results suggest a possible correlation between the lower expression of CD14 receptor on neonatal cells and the reduced secretion of proinflammatory cytokines by these cells. This decreased production may possibly contribute to the low ability of neonates to develop fever.     

Possible protective role of growth hormone in hypoxia-ischemia in neonatal rats

Perinatal asphyxia still constitutes a clinical hazard associated with considerable neurologic morbidity. Several growth factors, including insulin-like growth factor-I (IGF-I), have been reported to have a neuroprotective effect in experimental models of hypoxic ischemia (HI). In the present study, we have applied solution hybridization for quantification of the time course for mRNA expression of IGF-I, IGF-I receptor, and growth hormone (GH) receptor after HI in 7-d-old rats. There was a significant increase in IGF-I mRNA in the damaged hemisphere 72 h (1.19 +/- 0.28 vs 0.48 +/- 0.02 amol/microg DNA, p < 0.05) and 14 d (0.61 +/- 0.18 vs 0.19 +/- 0.05 amol/microg DNA, p < 0.05) after HI. In the contralateral hemisphere, both IGF-I and GH receptor mRNA had increased by 14 d after the insult (0.36 +/- 0.042 vs 0.13 +/- 0.011, p < 0.05, and 0.31 +/- 0.013 vs 0.11 +/- 0.004 amol/microg DNA, p < 0.001, respectively). There were no changes in IGF-I receptor mRNA throughout the study period. We have also evaluated the neuroprotective effect of GH after HI in neonatal rats. GH administered s.c. after HI in daily doses of 50 and 100 mg/kg provided a moderate neuroprotection of 20%. These results suggest a role for the GH/IGF-I axis in the neurochemical process leading to HI brain injury.     

宫内大肠杆菌感染导致新生大鼠脑白质损伤的实验研究

目的　探讨宫内感染后胶质纤维酸性蛋白 (GFAP)、GFAPmRNA和白介素 1βmRNA(IL 1βmRNA)、肿瘤坏死因子 αmRNA(TNF αmRNA)在新生大鼠脑组织中的变化。 方法　建立宫内大肠杆菌感染的大鼠模型 ,应用HE染色和免疫组化方法研究新生 1、3、7日龄大鼠脑白质组织病理特点和GFAP表达变化以及RT PCR法检测GFAPmRNA、IL 1βmRNA和TNF αmRNA的表达变化。结果　宫内感染后 7日龄大鼠脑白质病理改变包括脑白质染色淡 ,结构疏松等。感染组 7日龄大鼠GFAP阳性细胞数在脑室旁白质和海马区明显多于对照组 (脑室旁白质 9 73± 3 5 5vs 5 6 7± 1 90 ,P <0 0 5 ;海马 7 81± 3 6 1vs 2 16± 1 11,P <0 0 5 ) ;在胼胝体区两组比较差异无显著意义(P >0 0 5 )。感染组 1、3日龄大鼠GFAPmRNA表达水平明显高于对照组 (1日龄 0 2 5± 0 0 7vs0 15± 0 0 8,P <0 0 5 ;3日龄 0 5 0± 0 0 9vs 0 39± 0 0 8,P <0 0 5 ) ;而 7日龄大鼠GFAPmRNA表达水平两组比较差异无显著意义 (P >0 0 5 )。感染组 1日龄大鼠IL 1βmRNA和TNF αmRNA表达水平均明显高于对照组 (IL 1βmRNA :0 83± 0 19vs 0 5 0± 0 30 ,P <0 0 5 ;TNF αmRNA :0 74±0 30vs 0 30± 0 2 0 ,P <0 0 5 )。 3、7日龄大鼠IL 1βmRNA和TNF      

The effect of endurance-type exercise training on growth mediators and inflammatory cytokines in pre-pubertal and early pubertal males

Recent studies demonstrate an unexpected reduction in circulating levels of IGF-I after 5 wk of endurance-type exercise training in adolescent boys and girls and prepubertal girls. We hypothesized that the reduction in IGF-I would be accompanied by a training-associated stimulation of proinflammatory cytokines IL-1beta, IL-6, or tumor necrosis factor-alpha (TNF-alpha), each of which can inhibit the GH-->IGF-I axis. Healthy boys (age range 9-11 y old, mean Tanner 1.7) volunteered for the study and were randomized to control (n = 14) and training groups (n = 12) for 5 wk. After the intervention, significant increase in fitness was observed in the training group but not control group. Although IGF-I was correlated at baseline to peak oxygen consumption in all subjects, there was a significant decrease in IGF-I and IGF binding protein-3 in the training subjects (-12.8 +/- 7.3% and -17.5 +/- 7%, respectively, p < 0.05). In contrast, IGF binding protein-2, known to inhibit anabolic effects of IGF-I, increased in the training subjects (27.8 +/- 11%, p < 0.02) as did IL-1beta and TNF-alpha (51.5 +/- 30.22%, p < 0.02, and 44.5 +/- 23.2%, p < 0.02, respectively). Finally, we also found that GHBP was inversely correlated with fitness, suggesting altered GH function in more-sedentary boys. Thus, these data support the hypothesis that a sustained increase in physical activity can stimulate proinflammatory cytokines, which may contribute to suppression of the GH-->IGF-I axis. Physical activity can influence growth and development through its influence on anabolic and catabolic mediators.     

Increased levels of tumor necrosis factor-alpha and decreased levels of interleukin-12 p 70 in tracheal aspirates, within 2 hrs after birth, are associated with mortality among ventilated preterm infants.

OBJECTIVE: To determine the association of antibacterial interleukin (IL)-12 p 70 levels as well as the pathogen-induced proinflammatory cytokine response in tracheal aspirate (TA) to respiratory failure and mortality among ventilated preterm infants. DESIGN: A prospective observational clinical cohort study with measurements of cytokine levels and microbial cultures of TA from ventilated preterm neonates. Interleukin (IL)-1 beta, IL-8, IL-6, IL-10, IL-12 p 70, and tumor necrosis factor (TNF)-alpha were measured in TA within 2 hrs of birth, and comorbidity characteristics were recorded prospectively. The association between cytokine levels in TA and neonatal mortality was determined, with correction for comorbidity factors by means of multivariate stepwise logistic regression. SETTING: A single tertiary neonatal intensive care unit at the University Hospital of Antwerp, Belgium. PATIENTS: One hundred forty-one neonates born before a gestational age of 31 wks and who required ventilation were enrolled in the study; 31 (22%) died and 37 (26%) had airway colonization. MEASUREMENTS AND MAIN RESULTS: The airway colonization rate was significantly greater among deceased neonates (45% vs. 21%; chi-square, 7.4; p=.007). Neonates who died had a significantly lower IL-12 p 70 cytokine level (6 pg/mL vs. 11 pg/mL; p<.05) in their TA. Neonates with a low IL-12 p 70 cytokine level had more pronounced respiratory failure (significantly higher oxygenation index, higher degree of radiologic respiratory distress syndrome, higher critical index for babies score, and more surfactant use). Multivariate analysis revealed that, after correction for severity of disease by critical index for babies score, the degree of intraventricular hemorrhage (odds ratio, 5.0 [95% confidence interval, 2.6-9.7]), low IL-12 p 70 levels (odds ratio, 4.9 [95% confidence interval, 2.1-11.7]), and high TNF-alpha levels in TA (odds ratio, 3.5 [95% confidence interval, 1.6-7.5]) were significantly associated with neonatal mortality. CONCLUSIONS: Pathogen-induced excessive production of the proinflammatory cytokine TNF-alpha and lack of antibacterial IL-12 p 70 response in the TA are associated with increased neonatal mortality among ventilated preterm infants.     

肺炎大鼠心肌组织核因子-κB和炎症因子的变化及腺苷的影响

目的观察金黄色葡萄球菌(简称金葡菌)感染大鼠肺炎时心肌组织肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6 mRNA的表达和核因子-κB(NF-κB)活性,以及腺苷的作用.方法 30只SD大鼠被随机分为对照组、肺炎组和腺苷治疗组.将金葡菌经气管插管注入复制肺炎大鼠模型,于注菌后第2、3、4天静脉滴注腺苷治疗,每天90 min,剂量150 μg/(kg*min).第5天处死大鼠,立即取心脏液氮保存,心肌组织用于病理检测、提取核蛋白后用EMSA方法检测核因子-κB活性,采用RT-PCR方法检测TNF-α、IL-6 mRNA的表达.结果 (1)心肌病理组织检查示肺炎组病变明显,与正常组比较差异有显著意义(P<0.01), 经腺苷治疗后病变较肺炎组明显减轻(P<0.05);(2)肺炎组心肌中TNF-α(2.27±0.27)、IL-6 mRNA(1.89±0.31)的表达高于对照组(1.05±0.16、1.12±0.25)(均P<0.01);腺苷治疗组(1.25±0.18、1.31±0.25)低于肺炎组(均P<0.01),与对照组比较差异无显著意义;(3) 肺炎组心肌中NF-κB 活性(13 033±1 286)高于对照组(383±15)(P<0.01),腺苷治疗组(4 487±562)低于肺炎组(P<0.01).结论金葡菌感染大鼠肺炎可致心肌损害,NF-κB和细胞炎症因子IL-6和TNF-α参与心肌损伤的发生和发展,外源性腺苷可通过抑制NF-κB活性,下调炎症因子TNF-α、 IL-6的基因表达,有利于炎症的减轻和保护心肌.     

肺泡巨噬细胞核转录因子κB和核转录因子抑制物κB-α在肺透明膜病中的表达

目的 探讨新生儿肺透明膜病（HMD）支气管肺泡灌洗液（BALF）中肺泡巨噬细胞（AM）核转录因子κB（NF-κB）和核转录因子抑制物κB-α（IκB-α）的表达及其在HMD中的发病机制。方法 31例HMD机械通气治疗的早产儿,分为存活组22例和死亡组9例,另19例无呼吸系统疾病的早产儿为对照组。收集BALF,分离和培养AM;离体实验用细菌内毒素（LPS）刺激各组AM,提取细胞核蛋白。NF-κB的表达检测采用电泳迁移率实验（EMSA）;应用免疫斑点杂交（Western blot）检测IκB-α的表达;用酶连免疫法（ELISA）测定BALF上清液中细胞因子IL-1β和IL-8含量。结果 存活组在上机后24地h和72hAM中NF-κB表达均明显高于对照组。死亡组在上机后24hAM中NF-κB表达明显增高,而72h时减低,并经LPS刺激后无NF-κB表达明显增高。在上机后24和72h对照组的AM中IκB-α表达高于存活组和死亡组。死亡组在上机后24和72h,AM中IκB-α表达差异无统计学意义,并经LPS刺激后也无IκB-α的再表达。NF-κB表达与IL-1β和IL-8明显正相关。结论 NF-κB的过度表达参与了新生儿肺透明膜病的病理生理发病机制,其途径可能降低IκB-α的表达和增加了IκB-α降解或两者都有。