严重烧伤早期肠黏膜组织热休克蛋白70的表达规律

目的探讨大鼠烧伤后早期肠黏膜组织热休克蛋白70(HSP70)的表达变化规律及其意义。方法采用大鼠烫伤模型,通过逆转录-聚合酶链反应(RT-PCR)、蛋白质免疫印迹(Westernblot)及免疫组化等方法,检测伤后3、6、12、24和48h不同时间点肠黏膜组织内HSP70及热休克因子1(HSF1)的表达分布情况。结果烫伤后3h肠黏膜组织内HSP70mRNA及蛋白表达均显著增加,分别在伤后6h和12h达高峰,伤后48h仍高于正常对照组(P均<0.01);伤后3h大鼠肠黏膜组织HSF1出现一过性降低,伤后6h其表达显著高于正常对照组,并呈逐渐增加的趋势直至持续到伤后48h(P均<0.01)。结论严重烧伤早期肠黏膜组织HSP70及HSF1表达均显著增加,提示严重烧伤早期即可引起肠黏膜组织细胞的应激反应,可能与细胞的自我保护机制启动有关。     

严重烧伤后脏器损害机制与防治

通过系列的临床前瞻性研究与动物实验，发现并从多方面进一步证实了严重烧伤早期各主要脏器均可发生损害；缺血和再灌流损伤、脏器水肿、内皮细胞损伤及多种炎症介质的异常释放，导致难以控制的介质病，是脏器损害的重要因素；延迟复苏快速补液和使用介质拮抗剂山莨菪碱及人参皂甙或一次性切痂是防治严重烧伤早期脏器损害的有效方法。     

核因子kB活化对烧伤血清诱导单核细胞细胞因子表达的影响

目的了解核因子(NF)κB活化对烧伤血清诱导单核细胞活化分泌细胞因子的作用,探讨烧伤血清激活单核细胞的机制。方法收集体外培养的人外周血单核细胞(PBMC),分别用正常人血清、烧伤患者血清、烧伤患者血清 吡咯烷二硫代氨基甲酸盐(PDTC)刺激后依次分为对照组、烧伤血清组、PDTC组。采用电泳迁移率分析法检测刺激前及刺激0.5、1.0、2.0、4.0h时PBMC的NF-κB活性;酶联免疫吸附测定法和原位杂交法检测刺激前及刺激1.0、2.0、4.0、6.0h时PBMC培养上清液中肿瘤坏死因子(TNF)α、白细胞介素(IL)8水平及TNF-αmRNA、IL-8mRNA的表达情况。结果血清刺激后,烧伤血清组PBMC NF-κB活性迅速升高,刺激1.0h时达峰值(30.2±3.5)×104积分灰度值,与对照组(4.4±0.8)×104积分灰度值比较差异有统计学意义(P<0.01).刺激2.0h后逐渐下降;而PDTC组NF-κB活性无明显升高,刺激1.0h时为(6.8±0.9)×104积分灰度值。烧伤血清组刺激PBMC1.0h时,TNF-αmRNA表达量和培养上清液中TNF-α水平即升高达峰值,并明显高于对照组(P<0·01);IL-8mRNA表达量和IL-8水平在刺激4.0h时达峰值,也明显高于对照组(P<0.01);而PDTC组PBMC培养上清液中TNF-α刺激1.0h时达峰值(0.52±0.06)μg/L;刺激4.0h时IL-8达峰值(239±20)ng/L,与对照组[(0.13±0.07)μg/L、<156ng/L]比较,差异有统计学意义(P<0·01).结论烧伤血清可通过活化NF-κB,启动PBMC对细胞因子的合成和释放,提示NF-κB活化在烧伤血清诱导PBMC分泌细胞因子的过程中起重要作用。     

微管干预剂对大鼠缺氧心肌细胞能量生成的影响

目的 了解缺氧条件下微管干预剂对大鼠心肌细胞能量生成的影响。方法 常规分离、培养大鼠心肌细胞，分为单纯缺氧组、缺氧＋秋水仙碱（微管解聚剂）组及缺氧＋5、10、15 mmol／L紫杉醇（微管稳定剂）组。每组细胞加入刺激剂后，缺氧培养0．5、1．0、3．0、6．0、12．0、24．0h。采用锥虫蓝染色检测细胞死亡率，常规比色法检测细胞肌酸激酶（CK）活性，高效液相色谱法检测细胞腺苷三磷酸（ATP）及腺苷二磷酸（ADP）含量。结果 （1）缺氧＋秋水仙碱组及缺氧＋15mmol／L紫杉醇组细胞培养1．0～24．0h死亡率均高于单纯缺氧组（P〈0．01）；缺氧＋5、10mmoL／L紫杉醇组6．0～24．0h时均低于单纯缺氧组（P〈0．05）。（2）缺氧＋秋水仙碱组培养1．0～12．0h时CK活性均高于单纯缺氧组（P〈0．01）。0．5～12．0h时，缺氧＋15mmoL／L紫杉醇组CK活性均高于单纯缺氧组（P〈0．01）；缺氧＋5、10mmol／L紫杉醇组低于单纯缺氧组（P〈0．05或P〈0．01）。（3）缺氧＋5mmol／L紫杉醇组培养0．5～6．0h ATP含量[（49．9±2．8）、（40．7±2．0）、（25．8±1．9）、（19．1±1．2）μg／10^6个细胞]高于单纯缺氧组[（42．9±5．8）、（29．5±1．8）、（18．2±0．9）、（14．1±0．7）μg／10^6个细胞，P〈0．05或P〈0．01]。0．5～12．0 h时，缺氧＋秋水仙碱组低于单纯缺氧组（P〈0．01）；缺氧＋15mmol／L紫杉醇组低于单纯缺氧组及缺氧＋10mmol／L紫杉醇组（P〈0．01）。各组ADP含量变化趋势与ATP相反。结论 微管解聚剂和高浓度微管稳定剂可使缺氧心肌细胞ATP含量锐减。适宜浓度的微管稳定剂在缺氧早期可促进心肌细胞能量生成，对心肌具有保护作用。     

严重烧伤后诊断心肌损伤若干指标的比较

目的：探讨ＴｎＴ、ＭＬＣ１和ＣＫＭＢ等反映心肌损伤的指标在严重烧伤后的变化规律。方法：利用大鼠３０％ＴＢＳＡⅢ度烧伤模型，动态观察伤后１、３、６、１２和２４小时血浆ＴｎＴ、ＭＬＣ１、ＣＫＭＢ、ＴＮＦ及心肌组织ＴＮＦ含量的变化。结果：烧伤后３￣６小时血浆ＴｎＴ、ＭＬＣ１、ＣＫＭＢ和ＴＮＦ即显著高于对照组，相关性分析表明ＴｎＴ、ＭＬＣ１、ＣＫＭＢ之间密切相关，且都与血将ＴＮＦ显著正相关。结论：ＴｎＴ、     

血管紧张素(1-7)和依那普利拉对烧伤血清离体灌注大鼠心脏功能的影响

Objective To investigate effects of angiotcnsin ( 1-7 ) [ Ang( 1-7 ) ] and enalaprilat on function of isolated rat heart perfused by burn serum. Methods Eighty SD rats were used to prepare burn serum. Hearts of another 24 SD rats were isolated to reproduce Langendorff perfusion model. The rat hearts were divided into different groups with different perfusion fluids as K-H buffer group, K-H buffer containing 20% burn serum group ( burn serum group) , K-H buffer containing 20% burn serum and 2 μg/mL enala-prilat group (enalaprilat group), and K-H buffer containing 20% burn serum and 1 nmol/mL Ang(1-7) group [ Ang(1-7) group]. The rat hearts were perfused for 30 mins with each of above-mentioned fluids in different groups. Then left ventrieular systolic pressure (LVSP) , left ventricular end diastolic pressure ( LV-EDP) , ± dp/dt max, coronary flow(CF) , level of creatine kinase (CK) and lactate dehydrogenase (LDH) in respective coronary effluent were determined. Results Compared with LVSP ( 11.2 ± 1.0 kPa, 1 kPa = 7.5 mm Hg), +dp/dt max (642±53 kPa/s), -dp/dt max (380±61 kPa/s) and CF level in K-H buffer group, CF, LVSP(5.9±0.8, 8.0±1.1, 8.9±1.3 kPa, respectively), +dp/dt max(275±37, 454±48, 479±63 kPa/s, respectively), - dp/dt max ( 135±35, 219±47, 277±58 kPa/s, respectively ) of burn serum group, those levels in Ang(1-7) group, and enalaprilat group were decreased obviously(P<0.05 or P <0.01 ), but LVEDP, level of CK and LDH in coronary effluent were increased. Compared with those parameters in burn serum group, CF, LVSP, ±dp/dt max of Ang(1-7) group and enalaprilat group were increased obviously(P<0.05 or P<0.01), and LVEDP, level of CK and LDH in coronary effluent were decreased obviously(P<0.01). Conclusions Ang(1-7) and enalaprilat can effectively improve left ventricular function of isolated rat heart perfused by burn serum and mitigate myocardial injury.     

依那普利拉对严重烫伤大鼠早期心肌力学的影响

目的 了解依那普利拉对严重烫伤大鼠早期心肌力学的影响.方法 将84只SD大鼠背部造成30%TBSA的Ⅲ度烫伤后,随机分为烫伤组,伤后按Parkland公式腹腔注射等渗盐水;小剂量治疗组、中剂量治疗组、大剂量治疗组,伤后即刻分别腹腔注射1、2、4 mg/kg依那普利拉.烫伤组、小剂量治疗组伤后1、3、6、12、24 h,中剂量治疗组、大剂量治疗组伤后6、12 h左心室置管检测大鼠左心室收缩压(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),并处死大鼠取心肌组织检测血管紧张素Ⅱ(AⅡ)含量.另取6只大鼠作为假伤组,模拟烫伤后检测以上指标.结果 伤后3～24 h,烫伤组及各剂量治疗组大鼠LVSP、LVEDP、±dp/dt max值普遍低于假伤组(P＜0.05或P＜0.01);而各剂量治疗组LVSP、LVEDP、±dp/dt max值普遍高于烫伤组(P＜0.05或P＜0.01);伤后6、12 h,大剂量治疗组±dp/dt max明显低于小、中剂量治疗组.伤后1 h,烫伤组心肌组织AⅡ含量[(53.0±2.6)pg/200 mg]明显高于假伤组[(14.8±0.7)pg/200 mg,P＜0.01],6 h达高峰,以后逐渐下降,伤后24 h仍明显高于假伤组(P＜0.01);伤后3～24 h.小剂量治疗组AⅡ含量均明显高于假伤组(P＜0.05或P＜0.01),但均低于烫伤组.伤后6 h烫伤组AⅡ含量为(145.2±14.5)pg/200 mg,高于小、中、大剂量治疗组[(65.1±0.9)、(53.6±1.1)、(34.2±0.9)pg/200 mg,P ＜0.01].结论 严重烫伤后早期心肌组织损害明显.心功能即明显下降,依那普利托注射液可以改善心肌力学指标、保护心功能,以小剂量效果最为明显.     

烧伤后早期心肌损害与防治

Isehemia/hypoxia is one of the key clinical issues following severe burns, and isehemic/hypoxic damage of tissues and organs is still hard to be prevented or minimized by various fluid resuscitation regimens . To those who suffered severe bums, even though fluid replacement therapy is delivered promptly, isehemic/hypoxie damage of organs is still inevitable. Previously, blood flow in vital organs such as heart was eonsidered not to be reduced because of blood redistribution under the circumstance of stress. The postbum cardiac dysfunction has been mainly attributed to the reduced blood flow returned to the heart due to decreased blood volume caused by increased capillary permeability. Therefore, postbum cardiac dysfunction has been considered to be the result of burn shock. During the past two decades, we have performed serial studies on severe burns, and found that isehemie/hypoxie myocardial damage and functional impairment of myocardium due to activation of reninangio tensin system existing in the heart itself occur immediately after severe bums even before significant reduction in blood volume secondary to an increase of capillary permeability . Such prompt myocardial damage leads to cardiac deficiency, and it is also a precipitating factor for bum shock and isehemic/hypoxie injury of systemic tissues and organs. Therefore, we called it " shock heart" in our reports. The cellular and molecular mechanisms leading to myocardial damage were systematically investigated. Strategies for prevention of early postburn myocardial damage and dysfunction, and a new effective burn shock resuscitation regimen "volume replacement" plus "dynamic support" (cardiac support and myocardial protection) have been proposed based on our previous studies.     

依那普利拉减轻大鼠烧伤早期脏器损害的研究

目的 探讨依那普利拉对烧伤早期内脏损害保护作用的量效关系.方法 随机将54只SD大鼠分为烫伤组(B组)和烫伤后小剂量、中剂量和大剂量依那普利拉治疗组(E1、E2、E3组),每组12只大鼠,另取6只大鼠不致伤作为正常对照组.检测烫伤前及伤后6 h和12 h动脉血压、血管紧张素Ⅱ、尿素氮(Bun)、肌酐(Cr)和肌酸激酶(CK)、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST),以及主要脏器组织病理变化.结果 B组血管紧张素Ⅱ明显升高,治疗组均明显低于B组(P均＜0.05),E2和E3组明显低于E1组;B组大鼠CK、Bun、Cr、ALT、AST均显著高于正常参考值(P均＜0.05),治疗组较B组不同程度降低,E1组下降明显(P＜0.05),各时相点基本与正常值接近;E2和E3组下降不明显,明显高于E1组;烫伤后各组动脉收缩压和舒张压均有不同程度下降,其中E2、E3组较E1组更明显,E1组较B组明显升高.结论 小剂量依那普利拉能够显著减轻严重烧伤后脏器损害的程度,但对动脉收缩压和舒张压无显著影响.     

血管紧张素(1-7)和依那普利拉对烧伤血清离体灌注大鼠心脏功能的影响

Objective To investigate effects of angiotcnsin ( 1-7 ) [ Ang( 1-7 ) ] and enalaprilat on function of isolated rat heart perfused by burn serum. Methods Eighty SD rats were used to prepare burn serum. Hearts of another 24 SD rats were isolated to reproduce Langendorff perfusion model. The rat hearts were divided into different groups with different perfusion fluids as K-H buffer group, K-H buffer containing 20% burn serum group ( burn serum group) , K-H buffer containing 20% burn serum and 2 μg/mL enala-prilat group (enalaprilat group), and K-H buffer containing 20% burn serum and 1 nmol/mL Ang(1-7) group [ Ang(1-7) group]. The rat hearts were perfused for 30 mins with each of above-mentioned fluids in different groups. Then left ventrieular systolic pressure (LVSP) , left ventricular end diastolic pressure ( LV-EDP) , ± dp/dt max, coronary flow(CF) , level of creatine kinase (CK) and lactate dehydrogenase (LDH) in respective coronary effluent were determined. Results Compared with LVSP ( 11.2 ± 1.0 kPa, 1 kPa = 7.5 mm Hg), +dp/dt max (642±53 kPa/s), -dp/dt max (380±61 kPa/s) and CF level in K-H buffer group, CF, LVSP(5.9±0.8, 8.0±1.1, 8.9±1.3 kPa, respectively), +dp/dt max(275±37, 454±48, 479±63 kPa/s, respectively), - dp/dt max ( 135±35, 219±47, 277±58 kPa/s, respectively ) of burn serum group, those levels in Ang(1-7) group, and enalaprilat group were decreased obviously(P<0.05 or P <0.01 ), but LVEDP, level of CK and LDH in coronary effluent were increased. Compared with those parameters in burn serum group, CF, LVSP, ±dp/dt max of Ang(1-7) group and enalaprilat group were increased obviously(P<0.05 or P<0.01), and LVEDP, level of CK and LDH in coronary effluent were decreased obviously(P<0.01). Conclusions Ang(1-7) and enalaprilat can effectively improve left ventricular function of isolated rat heart perfused by burn serum and mitigate myocardial injury.