去乙酰毛花甙与依那普利拉单用及配伍应用对烫伤大鼠脏器早期损害的影响

目的 了解去乙酰毛花甙与依那普利拉单用及两药配伍应用对严重烫伤大鼠心、肝、肾、肠早期损害的影响. 方法 将40只雄性Wistar大鼠按随机数字表法分为假伤组(模拟烫伤)、烫伤对照组、去乙酰毛花甙组、依那普利拉组、去乙酰毛花甙+依那普利拉组,每组8只.大鼠麻醉后给予背部30%TBSAⅢ度烫伤,伤后30 min腹腔注射乳酸钠林格液(4 mL·kg-1·1%TBSA-1)复苏治疗.补液同时去乙酰毛花甙组静脉注射去乙酰毛花甙0.2 mg/kg;依那普利拉组静脉注射依那普利拉1 mg/kg;去乙酰毛花甙+依那普利拉组静脉注射去乙酰毛花甙及依那普利拉,剂量同前.伤后6h,以多道生理信号采集处理系统记录各组大鼠心肌力学指标;以激光多普勒血流仪记录肝、肾、肠血流量;取大鼠静脉血检测心肌肌钙蛋白I(cTnI)、总胆汁酸(TBA)、β2微球蛋白(β2-MG)、二胺氧化酶(DAO). 结果 与假伤组比较,烫伤对照组大鼠各项心肌力学指标均显著降低;肝血流量为(158±32)血流灌注单位(PU)、肾(156±46)PU、肠(119±30)PU,亦显著降低(P＜0.05);血清cTnl(5.0±0.3)μg/L、TBA(82±23)μmol/L、β-MG(2.55±0.15)mg/L、DAO(1.52±0.08)kU/L,明显高于假伤组(P＜0.05).与烫伤对照组比较,去乙酰毛花甙组和依那普利拉组心肌力学指标均有不同程度提升,肝、肾、肠血流量增加(P＜0.05),血清cTnl、TBA、β2-MG浓度和DAO活性降低(P＜0.05).去乙酰毛花甙+依那普利托组大鼠心肌力学指标全部升高,血流量分别为肝(240±49)PU、肾(239±75)PU、肠(194±55)PU,明显升高(P＜0.05),血清cTnI为(3.4±0.2)μg/L、TBA(47±8)μmol/L、β2-MG(2.01±0.16)mg/L、DAO(1.17±0.15)kU/L,均明显降低(P＜0.05). 结论 严重烫伤后早期单用去乙酰毛花甙或依那普利拉,均能改善大鼠心功能,对肝、肾、肠损害有一定防治作用,两药配伍应用可产生协同作用.     

"休克心"对严重烫伤大鼠早期肝肾肠损害的启动作用

目的 了解"休克心"对严重烫伤大鼠早期肝、肾、肠损害是否具有启动作用.方法 将56只Wistar大鼠随机分为对照组(8只),不予烫伤;烫伤组(48只),大鼠背部造成30%TBSA Ⅲ度烫伤,设伤后0.5、1.0、3.0、6.0、12.0和24.0 h观察时相点,每时相点8只大鼠.伤后30 min按Park-land公式腹腔注射乳酸林格液(4 mL·kg-1·1%TBSA-1).检测大鼠肝、肾、肠血流量;动脉收缩压(SBP)、动脉舒张压(DBP)、平均动脉压(MAP)、左心室收缩压(LVSP)、左心室舒张末期压(LVEDP)、左心室压力最大上升/下降速率(±dp/dt max);抽取各组大鼠静脉血检测其血清心肌肌钙蛋白I(cTnI)、总胆汁酸(TBA)、β2微球蛋白(β2-MG)、二胺氧化酶(DAO)含量.结果 伤后1.0 h烫伤组大鼠肝、肾、肠血流量均明显降低.伤后12.0 h内均呈持续下降趋势,至伤后24.0 h仍显著低于对照组(P＜0.05或P＜0.01).烫伤组大鼠伤后1.0 h,LVSP和±dp/dt max即明显下降;伤后3.0 h,SBP、DBP、MAP明显下降;伤后6.0 h所有心脏功能指标均降低,至伤后24.0 h仍低于对照组(P＜0.01).与对照组[(1.71±0.07)μg/L]比较,伤后0.5 h烫伤组大鼠血清cTnI[(2.22±0.08)μg/L]即明显升高,伤后12.0 h[(7.07±0.44)μg/L]达峰值,伤后24.0 h[(4.57±0.30)μg/L]仍保持在较高水平(P＜0.01);伤后3.0 h血清TBA及伤后1.0 h血清β2-MG、DAO开始明显升高,并超过对照组(P＜0.05或P＜0.01),至伤后12.0 h仍呈上升趋势.结论 严重烫伤后心肌损害在时间上明显早于其他脏器,且与其他脏器损害指标和血流量呈显著相关,提示"休克心"可能是严重烫伤后早期肝、肾、肠血流量减少和损害的启动因素之一,但还需深入研究以进一步证明.     

内毒素/脂多糖对烫伤大鼠休克期肝脏脂肪代谢的影响

目的观察内毒素/脂多糖(LPS)对烫伤大鼠休克期肝脏脂肪代谢的影响。方法采用30%TBSAⅢ度烫伤大鼠模型,随机分为单纯烫伤组(烫伤组)和烫伤后LPS攻击组(攻击组),另设假烫对照组(对照组),每组20只。攻击组大鼠于烫伤后2h腹腔注射LPS,3.0mg/kg.伤后24、48h分别检测3组大鼠血浆LPS、肿瘤坏死因子(TNF)α、游离脂肪酸(FFA)含量和肝组织内腺苷三磷酸(ATP)、甘油三酯(TG)及丙二醛(MDA)含量,并进行肝组织形态学观察。结果对照组大鼠假烫后24、48h,血浆FFA水平分别为(0.4±0.3)、(0.5±0.3)mmol/L,烫伤组分别为(0.9±0.3)、(1.2±0.5)mmol/L,攻击组大鼠伤后增加至(2.3±0.3)、(2.5±0.4)mmol/L,后两组之间比较差异有统计学意义(P<0.01).伤后48h,烫伤组和攻击组的肝组织TG含量分别为(242±27)mmol/g和(530±30)mmol/g,ATP含量分别为(6.0±2.4)μmol/g和(1.7±0.5)μmol/g,组间比较差异有统计学意义(P<0.01).组织形态学检查见,烫伤组大鼠肝细胞脂肪变性和线粒体损伤程度明显轻于攻击组,对照组肝细胞形态正常。结论烧伤后早期LPS打击可引发脂源性能量利用障碍,并加剧肝脏脂肪变性。     

胰岛素强化治疗对严重烫伤大鼠血清凋亡配体的作用

目的 了解大鼠严重烫伤后血清凋亡相关配体的变化及胰岛素强化治疗的作用.方法 将150只Wistar大鼠随机分为假伤组、烫伤组和治疗组.烫伤组和治疗组烫伤后立即腹腔注射等渗盐水40 mL/kg复苏;治疗组伤后24 h皮下注射胰岛素0.25 U/100 g,以后每12小时注射1次,共注射5 d.第1～5天的剂量分别为0.25、0.50、0.75、1.00、1.25 U/100 g,将大鼠血糖控制在3～6 mmol/L.假伤组浸入37℃温水假伤后不进行液体复苏.于伤后1、4、7、10、14 d抽取各组大鼠腹主动脉血,采用酶联免疫吸附测定法检测血清TNF-α、可溶性Fas配体(sFasL)、可溶性Fas受体(sFas);放射免疫法检测血清胰岛素水平.结果 烫伤组大鼠伤后1 d血清TNF-α水平[(30.9±8.7)ng/L]即达高峰,与假伤组[(12.7±2.8)ng/L]和治疗组[(16.8±4.7)ng/L]比较,差异有统计学意义(P<0.01),以后逐渐下降;治疗组大鼠伤后血清TNF-α水平虽然有所上升,但在伤后7 d内明显低于烫伤组(P<0.01).烫伤组、治疗组大鼠血清sFasL分别在伤后7～14 d和4～10 d高于假伤组(P<0.05),此后逐渐恢复至正常水平.伤后4～10 d治疗组sFas水平明显高于烫伤组及假伤组(P<0.05).伤后7、10 d烫伤组大鼠血清sFasL与sFas比值高于假伤组,而治疗组则在伤后7 d低于烫伤组(P<0.05),伤后14 d 2组均接近正常水平.烫伤组大鼠血清胰岛素水平在伤后4～10d低于假伤组(P<0.05).治疗组从伤后第1天起血清胰岛素水平即显著升高,伤后4 d[(327±15)μU/mL]达高峰,并显著高于假伤组[(42±15)μU/mL,P<0.01]和烫伤组[(28±10)μU/mL,P<0.01],随着治疗的进行,该指标逐渐恢复到正常水平.结论 胰岛素可能通过调节凋亡配体的分泌而抑制烧伤后细胞凋亡.     

大鼠严重烧伤后早期心功能和脏器血流量的变化及关系

目的 了解大鼠严重烧伤后早期迅即发生的心功能和脏器血流量变化规律及关系.方法 将36只SD大鼠按随机数字表法分为假伤组(6只)和烧伤组(30只).烧伤组大鼠制成30%TBSA Ⅲ度烧伤模型,并设伤后10、30 min及1、3、6 h共5个时相点(每时相点6只);假伤组用37℃温水致假伤.检测2组大鼠心率、平均动脉压(MAP)、左心室收缩压(LVSP)、左心室舒张末期压(LVEDP)、左心室压力最大上升/下降速率(LV±dp/dt max),并以荧光微球法检测大鼠心脏、大脑、肾、脾、胃、回肠血流量.对LV±dp/dt max与心肌血流量进行相关性分析. 结果 (1)与假伤组比较,烧伤组大鼠伤后心率逐渐下降;伤后10 min,MAP、LVSP、LV+dp/dt max、LV-dp/dt max及心肌血流量均明显降低(F值分别为12.062、12.629、11.066、18.374、9.468,P值均小于0.01),其中心肌血流量由(6.8±0.8)mL·min~(-1)·g~(-1)降至(2.6±0.5)mL·min~(-1)·g~(-1).而后随着时间的推移,上述各指标逐渐回升,伤后1 h达最高值(LV-dp/dt max除外),此后再次降低,伤后3、6 h均显著低于假伤组(各指标F值同前,P值均小于0.01).烧伤组各时相点LVEDP与假伤组接近(F=1.205,P值均大于0.05).(2)与假伤组比较,烧伤组大鼠伤后10 min肾、脾、胃、回肠血流量亦明显下降(F值分别为22.694、20.856、12.653、7.293,P<0.05或P<0.01),但下降幅度不如心脏;伤后1 h或3 h达到最低值.烧伤组大鼠各时相点的大脑血流量与假伤组接近(F=1.812,P值均大于0.05).(3)Lv+dp/dt max和LV-dp/dt max与心肌血流量均呈显著正相关(r值分别为0.651和0.617,t值分别为4.456、4.222,P值均小于0.01). 结论 严重烧伤后极短时间内(伤后10 min)即可发生心肌缺血和心功能下降,心脏血流量迅即减少是心功能变化的重要原因,心肌损害和心功能下降可能是导致其他脏器血流量降低的重要因素之一.     

早期应用冬眠合剂对严重烫伤大鼠小肠的保护作用

目的 了解早期应用冬眠合剂对严重烫伤大鼠小肠的保护作用.方法 将66只雄性SD大鼠按随机数字表法分为假伤组6只、烫伤组30只、烫伤+冬眠合剂组30只.麻醉后,将后2组大鼠造成30%TBSAⅢ度烫伤,假伤组37℃水浴模拟烫伤.3组大鼠伤后均立即腹腔注射乳酸钠林格液(2 mL·kg-1·%TBSA-1)复苏;同时烫伤+冬眠合剂组皮下注射冬眠合剂(50 mg/mL哌替啶、25 mg/mL氯丙嗪、25 mg/mL异丙嗪各1 mL加入125 mL生理盐水中)12 mL/kg,假伤组和烫伤组注射生理盐水12 mL/kg.分别于伤后3、6、12、24、48 h取烫伤组与烫伤+冬眠合剂组大鼠各6只(假伤组伤后3 h取材),采集血液和小肠组织标本.观察烫伤组与烫伤+冬眠合剂组大鼠伤后24 h、假伤组伤后3 h小肠组织病理变化,并用免疫组织化学法检测小肠组织胞间黏附分子1(ICAM-1)和CD68的表达.采用ELISA法测定各组大鼠血浆D-乳酸、二胺氧化酶(DAO)、IL-1β、TNF-α、IL-10水平.数据行单因素方差分析.结果 (1)伤后24 h,烫伤组大鼠小肠黏膜轻度出血,炎症细胞浸润、上皮细胞脱落;烫伤+冬眠合剂组较烫伤组肠绒毛排列规则,无明显充血、水肿表现.(2)烫伤组小肠ICAM-1和CD68阳性表达率分别为(1.69±0.27)%和(0.80±0.09)%,均显著高于假伤组的(0.77±0.10)%和(0.30±0.05)%(F值分别为77.303、66.933,P<0.05或P<0.01)与烫伤+冬眠合剂组的(0.53±0.09)%和(0.32±0.06)%(F值同前,P值均小于0.01).(3)烫伤+冬眠合剂组大鼠伤后12、24 h D-乳酸水平明显低于烫伤组(F值分别为20.936、19.854,P值均小于0.01).烫伤+冬眠合剂组DAO水平于伤后3、12 h显著低于烫伤组(F值分别为21.930、11.342,P值均小于0.05).(4)烫伤组各时相点IL-1β、TNF-α水平均明显高于假伤组(P值均小于0.01),烫伤+冬眠合剂组伤后6、12、24 h IL-1β、TNF-α水平均低于烫伤组(F值分别为96.517、17.365、79.715与21.328、17.682、28.424,P<0.05或P<0.01);烫伤+冬眠合剂组各时相点IL-10水平均高于烫伤组,并在6、24 h时差异具有统计学意义(F值分别为8.668、19.634,P<0.05或P<0.01).结论 早期应用冬眠合剂可减轻严重烫伤大鼠小肠黏膜水肿和损害,该机制可能与其降低肠道ICAM-1的表达和血液炎症介质水平、减少肠道局部炎症细胞数量有关.     

伏立诺他对50% TBSA Ⅲ度烫伤大鼠脏器功能及血流量的影响

目的:探讨组蛋白去乙酰化酶抑制剂伏立诺他(SAHA)对50%TBSAⅢ度烫伤大鼠器官功能及脏器血流量的影响。方法:雄性SD大鼠48只,体重240~260g,随机分为3组:1单烫组,于100℃水浴中背部浸泡15s、腹部浸泡8s,烫伤后,立即腹腔内注射0.25ml生理盐水;2SAHA组,烫伤后立即腹腔内注射0.25ml SAHA注射液(7.5mg/kg,溶于4ml生理盐水中);3假烫组,37℃水浴浸泡后腹腔内注射0.25ml生理盐水。于伤后3h和6h采用多普勒血流仪测定肝、肾及小肠黏膜血流量,取腹主动脉血检测血清丙氨酸转氨酶(ALT)含量、肌酐(Cr)含量、肌酸激酶同工酶(CK-MB)活性、神经特异性烯醇化酶(NSE)含量和二胺氧化酶(DAO)活性。结果:伤后3h,SAHA组肝、肾和小肠黏膜血流量显著高于单烫组(P均<0.05);SAHA组6h小肠黏膜血流量也显著高于单烫组(P<0.05)。SAHA组伤后3hCr、NSE含量和DAO活性显著低于单烫组(P均<0.05),伤后6hCK-MB、NSE含量和DAO活性均显著低于单烫组(P均<0.05)。结论:SAHA能改善50%TBSAⅢ度烫伤大鼠器官功能指标以及腹腔脏器血流量,保护重要脏器功能。     

血必净注射液对烫伤大鼠高迁移率族蛋白B1表达和急性肝损伤的影响

目的 了解血必净注射液对烫伤大鼠肝组织高迁移率族蛋白B1(HMGB1)表达及急性肝损伤的影响.方法 制作大鼠30%TBSA Ⅱ度烫伤模型,将78只大鼠按随机数字表法分为假伤组(18只)、烫伤组(30只)和血必净治疗组(30只),分别于伤后8、24、72 h处死取材.观察肝组织病理学变化;测定血清丙氨酸转氨酶(ALT)和天冬氨酸转氨酶(AST)水平;RT-PCR法检测肝组织HMGB1 mRNA表达,蛋白质印迹法及免疫组织化学法检测肝组织HMGB1蛋白相对表达量,结果 分别以积分吸光度比值、吸光度值表示.结果 光学显微镜下可见烫伤组大鼠肝组织有大量炎性细胞浸润,以伤后24 h较多;治疗组则明显减少.与假伤组比较,烫伤组大鼠血清ALT、AST水平显著增高(P<0.05或P<0.01),肝组织HMGB1基因和蛋白表达于伤后8～72 h显著增强(P<0.05或P<0.01).与烫伤组比较,治疗组大鼠血清ALT、AST水平有不同程度下降(P<0.05或P<0.01);伤后24、72 h肝组织HMGB1 mRNA表达分别为0.60±0.15、0.55±0.07,蛋白水平分别为163±13、160±16,显著低于烫伤组的0.75±0.12、0.78±0.11和200±13、175±14(P<0.05或P<0.01).结论 HMGB1 作为晚期炎性因子,参与了严重烫伤大鼠肝组织炎性反应的病理过程.血必净治疗可明显下调HMGB1表达,有助于减轻延迟复苏导致的急性肝损伤.     

牛磺酸对严重烧伤大鼠心肌损害的保护作用

目的　观察牛磺酸(Tau)对严重烧伤大鼠心肌损害的作用。　方法　将Wistar大鼠随机分为对照组(10只,不致伤)、烧伤组(60只)和Tau治疗组(60只)。后两组大鼠造成30%TBSAⅢ度烫伤(以下称烧伤),烧伤组伤后常规补液,Tau治疗组伤后腹腔注射Tau400mg/kg.于两组烧伤大鼠伤后1、3、6、12、24、48h检测其血浆中心肌肌钙蛋白T(cTnT)、丙二醛(MDA)的含量以及血浆、心肌组织中肿瘤坏死因子α(TNF- α)、血管紧张素Ⅱ(AngⅡ)的含量、心肌钙离子水平,用透射电镜观察心肌组织形态结构变化,并与对照组的上述指标进行比较。将烧伤组大鼠血浆TNF- α、AngⅡ检测结果分别与cTnT检测结果作相关性分析。　结果　烧伤组大鼠伤后3h起血浆cTnT水平较对照组(0.16±0. 03)μg/L显著升高(P<0. 01), 12h达峰值(6. 32±0. 41)μg/L, 48h仍显著高于对照组(P<0. 01).烧伤组伤后3—48h血浆MDA含量及心肌钙离子水平明显高于对照组(P<0. 01 );伤后6—48h血浆和心肌组织TNF- α含量显著高于对照组(P<0. 01);血浆及心肌组织中AngⅡ水平分别于伤后1—24h、3—24h明显高于对照组(P<0. 01).Tau治疗组上述指标在伤后多数时相点明显低于烧伤组(P<0. 01). 烧伤组大鼠伤后早期心肌肌丝断裂溶解、线粒体肿胀、嵴减少,Tau治疗组心肌组织接近正常。烧伤组     

牛磺酸对烫伤大鼠心肌线粒体成分和酶活性的保护作用

目的 了解牛磺酸对大鼠烫伤后心肌线粒体成分和酶活性变化的影响.方法 将120只大鼠背部脱毛后造成30%TBSA的Ⅲ度烫伤.分为烫伤组(60只),伤后腹腔注射等渗盐水(4mL·kg-1·1%TBSA-1);牛磺酸治疗组(60只),伤后腹腔注射20 g/L牛磺酸液(200 mg/kg).伤后1、3、6、12、24、48 h处死大鼠.取心肌组织检测心肌线粒体琥珀酸脱氢酶(SDH)、细胞色素c氧化酶(CCO)、超氧化物歧化酶(SOD)、Ca2+-腺苷三磷酸酶(ATPase)活性和细胞色素c、细胞色素aa3、丙二醛(MDA)、细胞质及线粒体内ca2+含量.另取10只大鼠作为对照组,模拟烫伤不予补液,1 h后处死大鼠取心肌组织检测以上指标.结果 烫伤组大鼠伤后1 h CCO活性即开始下降,伤后6、12 h下降最明显,而SDH活性在伤后6 h下降最明显,且各时相点均低于对照组;牛磺酸治疗组CCO和SDH下降不明显,伤后3、6、12 h CCO活性与烫伤组比较,差异有统计学意义(P＜0.05).伤后3、6、12、及24 h烫伤组心肌线粒体细胞色素c和细胞色素aa3均显著降低.而牛磺酸组虽然有所下降,但以上4个时相点的值均高于烫伤组(P＜0.05).烫伤组SOD活性在伤后3、6、12 h均显著性下降,ca2+ATPase活性在伤后3、6、12及24 h均有不同程度下降;而牛磺酸治疗组虽然有所下降,但以上4个时相点SOD、Ca2+-ATPase值均高于烫伤组(P＜0.05).伤后3～48 h烫伤组、牛磺酸治疗组MDA值均高于对照组(P＜0.05),但牛磺酸治疗组低于烫伤组(P＜0.05).伤后1 h烫伤组大鼠心肌线粒体中Ca2+即开始升高为13.7±1.5,伤后3、6、12、24 h分别为24.8±2.6、29.7±3.1、16.3±1.9及13.5±1.7.均高于对照组(10.7±1.6,P＜0.05);心肌细胞质中ca2+在伤后3、6、12、24 h也明显高于对照组(P＜0.05).伤后3、6、12及24 h牛磺酸治疗组大鼠心肌线粒体中ca2+浓度分别为16.8±2.8、18.7±1.9、10.5±1.8及13.3±1.7,均低于烫伤组.结论 牛磺酸对烫伤大鼠心肌线粒体成分和酶活性破坏具有保护作用,其机制与提高线粒体清除氧自由基的能力和减轻Ca2+超载有关.     

严重烫伤大鼠淋巴循环中三种重要炎症介质的变化

目的 了解淋巴途径在烫伤大鼠肠道细菌移位中的作用.方法 制备羰花青荧光染料CM-DIL标记的大肠埃希菌菌液(数量级109CFU/L).将60只成年雄性Wistar大鼠按照信封法随机分为烫伤组、假伤组,每组30只.2组大鼠经胃灌注已制备的标记菌液0.5 mL后,烫伤组致30%TBSA深Ⅱ度烫伤,伤后立即行液体复苏;假伤组大鼠皮肤经25℃水浴10 s模拟烫伤并同法复苏.采集2组大鼠伤后2、24、72 h(每时相点10只)的肠系膜淋巴结(MLN)、肝脏、肠系膜淋巴液(MLF)、肝静脉血标本.分别采用荧光示踪法和细菌培养法检测细菌移位情况;用鲎试剂显色基质法定量测定上述4种标本中内毒素含量,并计算MLF和肝静脉血的内毒素携带量.对实验数据行t检验或单因素方差分析.结果 (1)荧光示踪法检测显示活菌呈短棒状,液体标本中可见单体或两三个联体的可移动活菌;死菌呈不规则碎片状.假伤组伤后2 h有少量标记菌,24 h数量达高峰;烫伤组伤后2 h标记菌较多,24、72 h仍处于较高水平.烫伤组各种标本比较,MLN内标记菌最多,伤后24 h达高峰[(5872±1976)×103 CFU/g],明显多于假伤组[(216±110)×103 CFU/g,t=30.129,P=0.000],72 h有所减少但仍多于假伤组(t=4.323,P=0.000);血液内标记菌最少.(2)细菌培养法检测:假伤组120份标本中,29份细菌培养呈阳性占24.2%;烫伤组120份标本中,72份培养阳性占60.0%.2组大鼠除血液标本在各时相点均未检出活菌外,其余3种标本伤后2 h或24 h可培养出活菌.烫伤组MLN和肝脏较其余2种组织检出更多活菌;伤后24 h,该组MLN、肝脏以及MLF标本中细菌数量均明显多于假伤组(t值分别为4.353、4.354、4.965,P值均等于0.000).(3)内毒素含量:烫伤组大鼠伤后各时相点4种标本的内毒素含量均高于假伤组,其中肝脏、MLF内毒素含量伤后2 h即达高峰.此时相点烫伤组4种组织间内毒素含量比较,差异有统计学意义(F=258.47,P=0.000),其中肝脏、MLN、MLF内毒素含量较高,且明显高于假伤组(t值分别为43.378、43.123、22.423,P值均等于0.000);MLF内毒素含量约为血液中含量的9倍.(4)烫伤组伤后各时相点MLF、血液内毒素携带量均高于假伤组.结论 用CM-DIL标记细菌能够较全面反映细菌移位情况,淋巴途径在细菌移位中发挥重要作用.

Abstract：

Objective To investigate the role of lymphatics in bacterial translocation from intestine of rats with burn. Methods Escherichia coli (E. coli) labeled with chloromethylbenzamidodialkylcarbocyanine (CM-DIL) were prepared. Sixty adult male Wistar rats were randomly divided into scald group and sham injury group according to the envelope method, with 30 rats in each group. Rats in both groups were gavaged with 0. 5 mL fluid containing CM-DIL-labeled E. coli. Rats in scald group were inflicted with 30% TBSA deep partial-thickness scald (verified by pathological section) and resuscitated with fluid. Rats in sham injury group were sham injured by bathing in 25 ℃ water for 10 s(verified by pathological section)and also received with fluid infusion. Mesenteric lymph node (MLN), liver, mesenteric lymph fluid (MLF), and liver vein blood (LVB) were harvested at post injury hour (PIH) 2, 24, and 72. Bacteria translocation was detected with fluorescent tracing technique and bacteria culture. The endotoxin content in above-mentioned four kinds of specimens was quantitatively determined with chromogenic substrate limulus amebocyte lysate. The carrying capacity of endotoxin in MLF and LVB was calculated. Data were processed with t test or one-way analysis of variance. Results (1) Living bacteria were in short-stick form, and they were seen moving in single or in doubles or triples in sample fluid. Dead bacteria were in irregular aggregates. Labeled bacteria in small amount were detected in sham injury group, their number peaked at PIH 24. A large amount of labeled bacteria were detected in scald group at PIH 2, which peaked at PIH 24 and decreased at PIH 72. The largest amount of labeled bacteria were found in MLN in scald group as compared to those in the other samples, and the number peaked at PIH 24 [(5872 ± 1976) × 103 CFU/g], which was obviously higher than that [(216 ± 110) × 103 CFU/g, t =30. 129, P =0.000] in sham injury group. The number of bacteria decreased at PIH 72, but it was still significantly different from that in sham injury group ( t =4. 323, P =0.000). The number of bacteria in LVB was the smallest. (2) 29 (24.2%) samples out of the 120 samples in sham injury group were positive for bacteria. 72 (60.0%) samples out of the 120 samples in scald group were positive for bacteria. No alive bacterium was detected at any time point in LVB sample in both group; the other three samples were detected with alive bacteria since PIH 2. There were more alive bacteria detected in MLN and liver as compared with the other two kinds of samples in scald group. The amount of bacteria in MLN, liver, and MLF in scald group were higher than those in sham injury group(with t value respectively 4. 353, 4. 354, 4. 965, P values all equal to 0. 000). (3) The endotoxin level in each kind of sample at each time point was obviously higher in scald group than that in sham injury group, and it peaked at PIH 2 in liver and MLF. The difference of endotoxin level among 4 kinds of samples in scald group at PIH 2 was statistically significant(F = 258.47, P = 0. 000) , and the endotoxin level was higher in liver, MLN, and MLF. They were obviously higher than those in sham injury group(with t value respectively 43. 378, 43. 123, 22. 423, P values all equal to 0. 000). The endotoxin level in MLF was 9 times of that in LVB. (4) The carrying capacity of endotoxin in LVB and MLF at each time point in scald group was higher than that in sham injury group. Conclusions CM-DIL marked bacteria can reflect the microbial translocation condition. The lymphatic route is an important pathway for bacteria translocation.     

腹腔间隔室综合征大鼠血清D-乳酸及二胺氧化酶的变化及意义

目的 研究腹腔间隔室综合征(ACS)大鼠血清D-乳酸、二胺氧化酶(DAO)的变化及意义.方法 成年SD大鼠40只,按配对比较法随机分为对照组和实验组(各20只),实验组予建立ACS模型,对照组予假手术,建模成功后取大鼠血清检测D-乳酸及DAO含量(ELISA法);取小肠组织观察病理形态改变.结果 实验组大鼠小肠黏膜和黏膜下水肿、糜烂,部分上皮细胞坏死、脱落,其血清D-乳酸及DAO含量分别为(4.46±3.80) μg/mL、(1.24±2.09) U/L,对照组血清D-乳酸及DAO含量分别为(2.08±1.08) μg/mL、(0.11±0.11) U/L,二者比较差异有统计学意义(P＜0.05).结论 ACS大鼠血清D-乳酸及DAO含量与肠屏障功能损伤程度相关,D-乳酸及DAO可作为ACS病情的主要监测指标之一.     

小肠远端缺血预处理对大鼠肝脏热缺血再灌注损伤的保护作用

目的 观察小肠远端缺血预处理对大鼠肝脏热缺血再灌注损伤的保护作用.方法 将40只Wistar大鼠被随机分为4组:假手术组(Sham)、单纯远端缺血预处理组(RJPC)、单纯缺血再灌注组(IR)和远端缺血预处理+缺血再灌注组(RIPC+IR).远端缺血预处理方式采用于小肠系膜根部游离动脉血管并夹闭5 min后开放5 min,反复3次.缺血再灌注模型采用于肝蒂阻断肝脏供血45 min,阻断范围占整个肝脏的70%,开放复流3 h.检测血液中谷丙转氨酶(ALT)、乳酸脱氢酶(LDH)、一氧化氮(NO)和内皮素(ET)、肝脏苏木素-伊红(HE)病理、心血管指标.结果 复流3 h后,RIPC+IR组的ALT、LDH、心血管指标[平均动脉血压(MAP)、外周血氧饱和度(SaO2)]为(434.26±133.42)U/L、(2536±181)U/L、(83.1±7.3)mm Hg(1 mm Hg＝0.133 kPa)和(97.4±0.5)%,明显好于IR组(953.64±114.12)U/L、(5734±296)U/L、(67.1±7.4)mm Hg和(93.1±0.6)%(P<0.05).RJPC+IR组肝脏HE病理改变程度比IR组小.门静脉中IR组血清NO浓度(15.54±2.34)μmoL/L低于RIPC+IR组(18.10±1.82)μmol/L(P<0.05),外周血中,IR组血浆ET浓度(672.4±63.1)ng/L高于RIPC+IR组(451.7±63.6)ng/L(P<0.05),门静脉中IR组血清ET浓度(612.5±48.2)ng/L高于RIPC+IR组(401.5±51.2)ng/L(P<0.05).结论 小肠RIPC可以减轻肝脏缺血再灌注损伤,具有简便、易操作的特点,NO及ET可能在其中发挥了重要作用.     

The effect of ethyl pyruvate on oxidative stress in intestine and bacterial translocation after thermal injury

BACKGROUND: Thermal injury causes a breakdown in the intestinal mucosal barrier due to ischemia reperfusion injury, which can induce bacterial translocation (BT), sepsis, and multiple organ failure in burn patients. The aim of this study was to investigate the effect of ethyl pyruvate (EP) on intestinal oxidant damage and BT in burn injury. MATERIALS AND METHODS: Thirty-two rats were randomly divided into four groups. The sham group was exposed to 21 degrees C water and injected intraperitoneal with saline (1 mL/100 g). The sham + EP group received EP (40 mg/kg) intraperitoneally 6 h after the sham procedure. The burn group was exposed to thermal injury and given intraperitoneal saline injection (1 mL/100 g). The burn + EP group received EP (40 mg/kg) intraperitoneally 6 h after thermal injury. Twenty-four hours later, tissue samples were obtained from mesenteric lymph nodes, spleen, and liver for microbiological analysis and ileum samples were harvested for biochemical analysis. RESULTS: Thermal injury caused severe BT in burn group. EP supplementation decreased BT in mesenteric lymph nodes and spleen in the burn + EP group compared with the burn group (P < 0.05). Also, burn caused BT in liver, but this finding was not statistically significant among all groups. Thermal injury caused a statistically significant increase in malondialdehyde and myeloperoxidase levels, and EP prevented this effects in the burn + EP group compared with the burn group (P < 0.05). CONCLUSION: Our data suggested that EP can inhibit the BT and myeloperoxidase and malondialdehyde production in intestine following thermal injury, suggesting anti-inflammatory and anti-oxidant properties of EP.     

大鼠肠道缺血再灌注损伤对远隔组织Toll样受体4内源性配体表达的影响

目的 研究大鼠缺血再灌注损伤和淋巴液引流后,Toll样受体4(TLR4)的内源性配体高迁移率族蛋白1(HMGB1)的表达以及远隔组织的损伤.方法 24只健康雄性SPF级SD大鼠被随机分为假手术组(Sham)、肠道缺血再灌注组(I/R)和肠道缺血再灌注+淋巴液引流组(I/R+引流),每组8只.在肠道缺血再灌注损伤后检测远隔器官肺、肝和肾脏的损伤程度,肠道以及远隔器官肺、肝脏中TLR4内源性配体HMGBI的表达.结果 HE染色以及HMGB1免疫组织化学染色结果显示I/R组和I/R+引流组损伤较Sham组重,L/R组细胞出现大量黄染,表明I/R损伤时HMGB1的表达增加,而I/R+引流组的大鼠损伤显著轻于I/R组.Western blot检测显示I/R组的空肠、回肠、肝脏和肺组织中的HMGB1表达显著增加,其HMGB1/β-actin灰度值分别为0.3145±0.0549、1.7352±0.3280、1.4443±0.0926、3.1382±0.4202;引流淋巴液可以减轻损伤,其HMGB1表达均显著降低(P＜0.05),HMGB1/β-actin灰度值分别为0.1745±0.0327、1.1083±0.2098、1.1862±0.1221、2.1095±0.1993.结论 大鼠肠道缺血再灌注损伤时,肠道和远隔组织的损伤与TLR4的内源性配体HMGB1表达增加呈正相关.淋巴引流能阻断"肠-淋巴"途径,减少肠道来源的HMGB1对肠道以及远隔组织的损伤.     

组蛋白去乙酰化酶抑制剂对50％总体表面积烫伤大鼠存活率和脏器功能的影响

目的：研究组蛋白去乙酰化酶抑制剂对无液体复苏时致死性烫伤休克大鼠存活率和脏器功能的改善作用.方法：64只SD雄性大鼠随机分为4组：假烫组（n=10）,烫伤组（n=18）,烫伤＋2-甲基-2-乙酸组（2M2P组,n=18）和烫伤＋丙戊酸钠组（VPANa组,n=18）.烫伤组于80 ℃水浴浸泡背部15 s、双下肢15 s、腹部8 s,造成50%TBSAⅢ度烫伤.假烫组于37 ℃水浴浸泡,部位和时间与烫伤组相同. 2M2P组和VPANa组致伤方法同烫伤组,并于烫伤后即刻皮下注射2M2P或VPANa 300 mg/kg.各组大鼠烫伤深度经组织病理证实,于伤后2h和6h取腹主动脉血检测血清丙氨酸转氨酶（ALT）、肌酐（Cr）和肌酸激酶同工酶（CK-MB）等脏器功能指标.另66只大鼠随机分为烫伤组（n=18）、2M2P组（n=24）和VPANa组（n=24）,观察其伤后6 h和12 h生存率.结果：VPANa组生存时间为（776.7±89.5）min,显著高于烫伤组[（360.8±27.4）min]和 2M2P组[（512.5±52.2）min],差异具有显著性（P＜0.05）.VPANa组伤后6 h和12 h生存率分别为83.3%和50.0%,显著高于烫伤组（50.0%和0）和2M2P组（66.7%和16.7%）,差异具有显著性（P＜0.05）;2M2P组6 h和12 h生存率也显著高于烫伤组（P＜0.05）.烫伤及烫伤后各处理组伤后2 h和6 h ALT、Cr和CK-MB均显著高于假烫组（P＜0.05）.伤后6 h VPANa组ALT、Cr和CK-MB显著低于烫伤组和2M2P组（P均＜0.05）,2M2P组虽低于烫伤组,但差别无统计学意义.结论：组蛋白去乙酰化酶抑制剂能显著改善致死性烫伤休克大鼠脏器功能指标,延长动物生存时间.丙戊酸钠作用明显强于2M2P,有希望成为战场或灾害现场无液体复苏条件下救治致死性烧伤休克的潜力药物.     

Heparin-binding epidermal growth factor–like growth factor attenuates acute lung injury and multiorgan dysfunction after scald burn

Background

Impaired gut barrier function and acute lung injury (ALI) are significant components of the multiorgan dysfunction syndrome that accompanies severe burns. Heparin-binding epidermal growth factor–like growth factor (HB-EGF) has been shown to reduce inflammation, preserve gut barrier function, and protect the lungs from acute injury in several models of intestinal injury; however, comparable effects of HB-EGF after burn injury have never been investigated. The present studies were based on the hypothesis that HB-EGF would reduce the severity of ALI and multiorgan dysfunction after scald burns in mice.

Materials and methods

Mice were randomized to sham, burn (25% of total body surface area with full thickness dorsal scald), and burn + HB-EGF groups. The HB-EGF group was pretreated with two enteral doses of HB-EGF (1200 μg/kg/dose). Mice were resuscitated after injury and sacrificed at 8 h later. Their lungs were harvested for determination of pulmonary myeloperoxidase activity, wet:dry ratios, and terminal deoxynucleotidyl transferase dUTP nick end label and cleaved caspase 3 immunohistochemistry. Lung function was assessed using the SCIREQ Flexivent. Splenic apoptosis was quantified by Western blot for cleaved caspase 3, and intestinal permeability was measured using the everted gut sac method.

Results

Mice subjected to scald burn injury had increased lung myeloperoxidase levels, increased pulmonary and splenic apoptosis, elevated airway resistance and bronchial reactivity, and increased intestinal permeability compared with sham mice. These abnormalities were significantly attenuated in mice that were subjected to scald burn injury but treated with enteral HB-EGF.

Conclusions

These data suggest that HB-EGF protects mice from ALI after scald burn and attenuates the severity of postburn multiorgan dysfunction.