细胞凋亡在严重烧伤大鼠肠粘膜屏障损伤中的作用

目的：研究烫伤后大鼠小肠粘膜细胞凋亡在肠粘膜屏障损伤中的作用。方法：Ｗｉｓｔａｒ大白鼠，致３０％Ⅲ度烫伤，随机分为正常对照组、烫伤不复苏组及烫伤复苏组。分别在伤后２、４、６、１２、２４ 小时活杀动物，取小肠的回盲部，运用原位凋亡检测试剂盒，光镜下观察小肠粘膜细胞凋亡变化，同时观察其病理形态变化。结果：①凋亡细胞以粘膜表皮细胞为主。②凋亡细胞的数量以伤后６～１２小时最多，分布于绒毛顶端，后延伸至绒毛中下部；伤后２４小时凋亡细胞数量明显减少，仍多于正常对照组。提示大鼠小肠粘膜细胞凋亡的高峰在伤后６～１２ 小时与肠源性细菌、内毒素易位的高峰一致。③不复苏组动物小肠凋亡细胞数量较复苏组多。结论：肠粘膜细胞凋亡致肠粘膜屏障功能损伤共同参与了肠源性感染的发病过程；烫伤后大鼠小肠粘膜细胞的凋亡可能与缺血、缺氧有关，氧自由在其中发挥了重要作用。     

大黄对烫伤大鼠肠粘膜上皮细胞线粒体呼吸链的影响

目的：研究大黄对烫伤后大鼠肠粘膜上皮细胞线粒体呼吸链的影响。方法：采用大鼠背部２５％Ⅲ度烫伤模型，分离小肠粘膜上皮细胞内线粒体，监测细胞色素ａａ３，ｂ，ｃ和ｃ１的水平，并观察大黄在其中的影响。结果：烫伤后２小时肠粘膜上皮细胞线粒体细胞色素ａａ３，ｂ和ｃ１较为稳定，而在伤后６小时出现明显丢失，与烫伤组０．５和２小时及对照组比较，Ｐ均〈０．０５，而细胞色素ｃ在烫伤后早期即有明显丢失，于伤后６小时最为严     

烫伤对小鼠葡萄糖调节蛋白78表达的影响

目的：研究烫伤对小鼠各器官葡萄糖调节蛋白７８（ＧＲＰ７８）表达的影响。方法：Ｃ５７ＢＬ／６ 小鼠，体重２０～２５ ｇ，制成２０％ 体表面积Ⅲ度背部烫伤模型。烫伤后０．５、１、２４和７２小时采集肝、脾、肾、烫伤和未烫伤皮肤，以及肺、脑和右大腿肌肉，抽提各器官总ＲＮＡ，以逆转录 多聚酶链式反应检测烫伤后各器官内ＧＲＰ７８ 表达情况。结果：①肝脏：烫伤后１小时ＧＲＰ７８ 表达明显增加（Ｐ＜ ０．０５），２４小时仍高于对照组，伤后７２小时恢复至对照组水平；②皮肤：烫伤后０．５ 小时表达无明显增加，１ 小时烫伤组表达明显超过对照组（Ｐ＜ ０．０５），伤后２４小时表达仍高于对照组，于７２ 小时恢复至对照组水平。③其他脏器：烫伤后ＧＲＰ７８ 在脾、肾、脑、肺和肌肉内表达与对照组无显著差异。结论：烫伤能诱导皮肤、肝脏内ＧＲＰ７８ 基因大量表达。     

丙酮酸乙酯对烫伤延迟复苏大鼠多器官功能及死亡率的影响

目的观察丙酮酸乙酯（EP）对烫伤延迟复苏动物多器官功能及死亡率的影响，探讨其保护作用的机制。方法采用雄性Wistar大鼠30％总体表面积Ⅲ度烫伤模型。实验分为两部分进行：①死亡率观察：130只大鼠按照随机数字表法分为假烫伤组（n=10）、烫伤组（n=60。伤后6h腹腔注射生理盐水40ml／kg进行复苏，然后按照不同时间点腹腔注射等量生理盐水）和EP组（n=60。伤后6h腹腔注射生理盐水40ml／kg进行复苏，按不同时间点腹腔注射EP液40mg／kg。每日2次．间隔12h。给药3d）。除假烫伤组外，各组又分为伤前2h（n=20）、伤后2h（n=20）和伤后12h（n=20）给药3个亚组。观察不同时间点各组动物7d死亡率。②器官功能观察：70只大鼠随机分为假烫伤组（n=10）、烫伤组（n=30）和EP组（n=30，伤后2h给药），并分别于伤后12、24和72h活杀，检测器官功能指标改变。结果与烫伤组相比，伤后12hEP组动物死亡率显著降低（35．0％比75．0％，P〈0．05）。伤后2hEP组血清丙氨酸转氨酶、天冬氨酸转氨酶、尿素氯、肌酐、肌酸激酶水平及肺组织髓过氧化物酶活性均明显下降（P〈0．05或P〈0．01）。结论EP能明显改善严重烫伤延迟复苏大鼠的预后，并对重要器官功能具有显著保护作用。     

氧自由基对烫伤大鼠延迟复苏后肠上皮细胞凋亡的影响

目的：观察烧伤延迟复苏后肠粘膜上皮细胞凋亡的发生规律及与氧自由基损伤的关系。方法：１５０只雄性Ｗｉｓｔａｒ大鼠随机分为Ａ组（烫伤立即复苏组,ｎ＝６０）、Ｂ组（烫伤延迟复苏组,ｎ＝５０）、Ｃ组（Ｎ－乙酰半胱氨酸（ＮＡＣ）治疗组,ｎ＝２０）和Ｄ组（别嘌呤醇治疗组,ｎ＝２０）。３０％总体表面积（ＴＢＳＡ）Ⅲ度烫伤大鼠伤后６小时进行复苏。观察伤后肠粘膜上皮细胞凋亡发生规律,测定Ａ、Ｂ组伤后３、６、１２、２     

延迟快速血定安复苏对烫伤犬血流动力学及酸碱平衡的影响

目的：探讨延迟快速血定安复苏对烫伤犬血流动力学及酸碱平衡的影响。方法：复制４０％体表面积（ＴＢＳＡ）Ⅲ度犬烫伤延迟快速复苏（伤后６小时）模型,实验分为烫伤不补液对照组（ＢＣ组）、延迟血浆复苏组（ＤＰ组）和延迟血定安复苏组（ＤＧ组）,观察其股动脉血压（ＢＰ）、心排血量（ＣＯ）、肺动脉契压（ＰＡＷＰ）、动脉血ｐＨ及血浆乳酸含量的变化。结果：①ＢＣ组伤后１２～３６小时内动物全部死亡,ＤＰ、ＤＧ２组均存丰     

烫伤延迟复苏后小肠固有层和上皮内淋巴细胞凋亡率及凋亡相关基因表达的变化

目的：探讨延迟复苏对烫伤大鼠小肠固有层淋巴细胞(LPL)和上皮间质淋巴细胞(IEL)凋亡率及凋亡相关基因表达的影响。方法：Wistar大鼠30只,单盲法随机分为立即复苏组(ER,n＝12)和延迟复苏组(DR,n＝12),30％体表面积Ⅲ度烫伤合并延迟复苏模型;6只作为假伤对照。采用DNA电泳、片段百分率测定及逆转录—聚合酶链反应(RT—PCR)观察伤后LPL、IEL凋亡百分率(ap％)及ICE、bcl—2基因mRNA表达变化。结果：伤后LPL、IEL的ap％均显著高于伤前(P均＜0．01);伤后12hDR组LPL、IEL的ap％显著高于ER组(P均＜0．01)。伤后6h LPL、IEL基因组DNA电泳均可见凋亡特征性梯形条带。烫伤后LPL、IEL ICE基因表达均明显增强,且DR组显著高于ER组(P＜0．05或P＜0．01)。LPL、IEL伤前bcl—2mRNA强表达,伤后极弱表达;DR组相同时问点表达显著弱于ER组(P＜0．05或P＜0．01)。结论：促凋亡基因ICE表达增强而抑凋亡基因bcl—2表达减弱,可能是烫伤延迟复苏后LPL、IEL凋亡剧增的重要原因之一。     

烧伤延迟复苏诱导肝细胞凋亡

目的：观察烧伤延迟复苏再灌注能否引起肝细胞凋亡及探讨其发生机制。方法：３０％ 体表面积Ⅲ度烫伤大鼠烫伤后６ 小时进行复苏,再灌注２、１０ 和１８ 小时抽提肝组织中基因组ＤＮＡ,用聚合酶链反应（ＰＣＲ）试剂盒检测细胞凋亡,ＰＣＲ产物行琼脂糖凝胶电泳,观察基因组ＤＮＡ 是否出现特征性的凋亡图像,观察肝组织中一氧化氮（ＮＯ）和中性粒细胞特有的酶——髓过氧化物酶（ＭＰＯ）的变化。结果：烫伤延迟复苏后肝组织基因组ＤＮＡ 出现标志凋亡的“梯形”图象,发生凋亡的大鼠肝细胞随延迟复苏时间的延长而增加。ＮＯ 在延迟复苏后２ 小时显著降低,ＭＰＯ 含量延迟复苏组显著高于烫伤后立即复苏组。结论：烧伤后延迟复苏导致肝组织细胞凋亡,其发生与ＮＯ含量减少、肝组织内中性粒细胞聚集有关     

山莨菪碱对烫伤大鼠血浆内毒素及肿瘤坏死因子-α水平的影响

目的：探讨山莨菪碱改善创伤和烧伤后全身炎症反应综合征的作用机制。方法：雄性Ｗｉｓｔａｒ大鼠背部２５％－３０％深Ⅱ－Ⅲ度烫伤,烫伤后分别给予５％葡萄糖盐水或山莨菪碱,检测血浆内毒素（ＬＰＳ）和肿瘤坏死因子－α（ＴＮＦ－α）的浓度。结果：大鼠血中ＬＰＳ烫伤后８－１６小时升高,２４小时即恢复正常;而血中ＴＮＦ－α的升高表现为双峰伏,第１个高峰出现在伤后２小时,第２个高峰出现在伤后１６－２４小时,均与血中     

抗栓酶Ⅲ号对烫伤大鼠休克期的治疗作用观察

通过肺，肾组织超微结构病理变化的观察探讨抗栓酶Ⅲ号在烫伤大鼠休克期的治疗作用方法：复制２０％体表面积的Ⅲ度烫伤大鼠模型，随机分为正常组，烫伤对照组和烫伤治疗组，伤后２４小时取肺，肾组织进行电镜观察。烫伤对照组烫伤后２４小时肺泡腔明显塌陷呈局灶性实变，多见代偿性肺泡扩张，肺泡腔消失或仅有狭窄缝，线粒体肿胀；肾足细胞显著肿胀，肾小球毛细血管腔中有微血栓形成。     

血必净注射液对烧伤延迟复苏大鼠器官功能及死亡率的影响

目的 观察血必净注射液对烧伤延迟复苏大鼠多器官功能损害和死亡率的影响。方法 采用大鼠30％总体表面积Ⅲ度烫伤模型。130只雄性Wistar大鼠按随机数字表法分为假伤组（n=10）、烫伤组（n=60，伤后6h腹腔内注射40ml／kg生理盐水）和血必净组（n=60，血必净注射液4ml／kg，每日2次）。除假伤组外，各组再根据不同给药时间点分为伤前2h（n=20）、伤后2h（n=20）和伤后12h（n=20）给药组。分别观察不同时间点各组动物7d的死亡率及伤后12h多器官功能改变。结果 与烫伤组相比，伤后12h血必净组动物死亡率显著降低（75．0％比40．0％。P〈0．05）；同时，血必净组伤后12h血清丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）、尿素氮（BUN）、肌酐（Cr）及肌酸激酶（CK）水平均明显降低（P〈0．05或P〈0．01）。结论 血必净注射液能够明显降低严重烧伤延迟复苏大鼠的死亡率，并对重要器官具有保护作用。     

Early fluid resuscitation improves outcomes in severely burned children

BACKGROUND: Recent evidence suggests that timely fluid resuscitation can significantly reduce multiorgan failure and mortality in thermally injured children. In this study, children who received fluid resuscitation within 2 h of a thermal injury were compared with children in which fluid resuscitation was delayed by 2-12 h. We hypothesized that fluid resuscitation given within 2 h of a thermal injury attenuates renal failure, cardiac arrest, cardiac arrest deaths, incidence of sepsis, and overall mortality. METHODS: A retrospective chart review was made on 133 children admitted to our institute from 1982 to 1999 with scald or flame burns covering more than 50% of their body surface area. Comparisons between early (< 2 h of injury) or delayed (> or = 2 h of injury) fluid resuscitation were made in children experiencing renal failure, sepsis, non-survivors with cardiac arrest requiring pulmonary and advanced life support, and overall mortality. Comparisons were made using the chi2-test with Yates' continuity correction and joint binomial confidence intervals using the Bonferroni correction. RESULTS: The incidence of sepsis, renal failure, non-survivors with cardiac arrest, and overall mortality was significantly higher in burned children receiving fluid resuscitation that was delayed by 2 h or more compared with those receiving fluid resuscitation within 2 h of thermal injury (P < 0.001). CONCLUSIONS: Data suggest that fluid resuscitation, given within 2 h of a thermal injury, may be one of the most important steps in the prevention of multi-organ failure and mortality.     

拮抗晚期糖基化终末产物受体对烫伤延迟复苏大鼠多器官功能及死亡率的影响

目的 观察拮抗晚期糖基化终末产物受体(RAGE)对烫伤延迟复苏动物多器官功能及死亡率的影响,并探讨其作用机制.方法 选取雄性Wistar大鼠,采用重度烫伤延迟复苏模型(30%总体表面积Ⅲ度烫伤).实验分为两部分.死亡率观察:130只大鼠被随机分为假手术组(n=10)、烫伤组(n=60)及RAGE抗体治疗组(n=60),观察伤后7 d内每日动物的存活率.器官功能观察:72只大鼠被随机分为假手术组(n=24)、烫伤组(n=24)及RAGE抗体治疗组(n=24),于伤后1、3、5和7 d各活杀6只动物,取血,用全自动生化分析仪测定肝、肾和心脏器官功能指标.结果 烫伤组伤后1～7 d,大鼠血中丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、肌酐(cr)、尿素氮(BUN)及肌酸激酶同工酶(CK-MB)水平均显著高于假手术组(P<0.05或P<0.01),其中ALT、AST、Cr及BUN水平均于伤后3 d达峰值;给予RAGE抗体治疗可不同程度降低烫伤动物血中各指标水平,其中AST在伤后1～7 d显著下降,余指标在伤后1～5 d均明显改善(P<0.05或P<0.01).RAGE抗体治疗组伤后7 d内每日大鼠存活率显著高于烫伤组(P<0.05或P<0.01).结论 RAGE抗体干预能明显改善重度烫伤延迟复苏大鼠的预后,并对重要器官功能具有显著保护作用.     

烫伤延迟复苏后肠上皮细胞凋亡诱导肠道内毒素和细菌移位

目的 :探讨烫伤延迟复苏后肠上皮细胞凋亡对肠道内毒素和细菌移位的影响。方法 :Wistar大鼠 110只 ,30 %总体表面积 ( STBA) 度烫伤 ,立即或伤后 6 h进行复苏。观察伤后肠上皮细胞凋亡率 ( ap% )变化 ,并测定了门静脉和体循环内毒素及肠系膜淋巴结 ( ML N)细菌移位率和移位量变化。结果 :电泳、原位末端标记( TU NEL )法和电镜均观察到伤后肠上皮凋亡梯形带和凋亡阳性细胞增多。延迟复苏组肠上皮细胞凋亡发生早且更严重 ;其门静脉内毒素水平及 ML N细菌移位量均显著高于立即复苏组 ( P<0 .0 1) ;门静脉内毒素变化与肠黏膜 ap%成显著正相关 (烫伤后立即复苏组 r=0 .936 ,P<0 .0 1;烫伤后延迟复苏组 r=0 .899,P<0 .0 5 )。结论 :烫伤后延迟复苏使肠黏膜上皮发生病理性凋亡 ,可能导致肠道细菌和内毒素移位增加。     

创伤后内毒素血症与脏器损害关系及其防治新方法的系列研究

目的：从不同的作用环节采用多种干预手段以阻断肠源性内毒素血症的发生，观察其对机体炎症反应、免疫反应、脏器损害和预后的影响。方法：采用多种动物分别建立了不同致伤方式诱发脓毒症及多脏器功能失常综合征（MODS）的模型；并结合临床病例进行前瞻性研究。结果：分别应用杀菌-通透性增加蛋白、抗核心脂多糖（LPS）单抗及Re型LPS抗血清、低剂量多粘菌素B、选择性消化道脱污染及抗肿瘤坏死因子（TNF）单抗等措施，可显著中和循环内毒素，能有效地减轻肝、肺、肾及肠道等器官损害和明显提高动物存活率；并且抗内毒素可不同程度地抑制循环和组织中细胞因子mRNA及蛋白质的表达和改善机体细胞免疫功能；临床观察显示，大面积烧伤和创伤患者24小时内血浆内毒素含量显著升高，其升高程度与血浆TNF呈正相关，这一趋势以并发脓毒症、MODS者尤为明显。结论：肠源性内毒素血症与脓毒症、脏器功能损害密切相关；创伤早期采取有效措施及时防止肠源性内毒素血症对创伤所致脓毒症及MODS具有一定的防护效应，动物预后明显改善；其作用机制与抑制细胞因子的基因表达、分泌及提高机体全身免疫状况有关。     

How well does the Parkland formula estimate actual fluid resuscitation volumes?

We had anecdotally observed that fluid resuscitation volumes often exceed those estimated by the Parkland Formula in adults with isolated cutaneous burns. The purpose of this study was to compare estimated and actual fluid resuscitation volumes using the Parkland Formula. We performed a retrospective study of fluid resuscitation in patients with burns > or = 15% TBSA. Patients with inhalation injury, high voltage electrical injury, delayed resuscitation, or associated trauma were excluded. We studied 31 patients (mean age 51 +/- 20 years, mean TBSA burn 27 +/- 10%). The 24 hour resuscitation volume of 13 354 +/- 7386 ml (6.7 +/- 2.8 ml/kg/%TBSA) was significantly greater than predicted (P = 0.001) and exceeded estimated volume in 84% of the patients. The mean urine output in the first 24 hrs was 1.2 +/- 0.6 ml/kg/hr. After the first 8 hours of resuscitation, the infusion rate decreased by 34% in 16 patients (DCR group), while in 15 patients the rate increased by 47% (INCR group). Both the DCR and INCR groups received significantly more fluid than predicted, (5.6 +/- 2.1 ml/kg/%TBSA and 7.7 +/- 3.1 ml/kg/%TBSA respectively). The INCR patients had significantly larger full thickness burns (14 +/- 11% vs 3 +/- 6%, P < 0.001). Our findings reveal that despite its effectiveness, the Parkland Formula underestimated the volume requirements in most adults with isolated cutaneous burns, and especially in those with large full thickness burns.     

Usefulness of warm fluid in acute burn resuscitation: an experimental study in dogs

Hypothermia is a common complication in patients with extensive burns, receiving massive volumes of fluid for resuscitation at ambient temperature. It is therefore important to maintain the body temperature of patients with extensive burns. The present study was performed to evaluate the usefulness of warm fluid for burn injury resuscitation. Ten dogs were used in this study. Full-thickness burns, involving 40% of the body surface, were generated in the backs of the animals. In the control group (n = 5), the fluid temperature was maintained at about 23 degrees C, while in other group (n = 5), the temperature of the fluid was maintained at 39 degrees C with a warming device. Cardiac output and urinary output were measured in both groups for up to 24 hours. The cardiac output decreased in all animals during the first two hours following injury. The cardiac dynamics remained depressed in the control group. By contrast, in animals treated with warm fluid, the cardiac output returned to the baseline level within 4 hours of resuscitative measures and then decreased slightly for the subsequent 20 hours. The urinary output was better in animals treated with warm fluid, indicating the improved hemodynamic state in these animals. These results suggested that the hemodynamic state in acute burn shock was ameliorated by the use of warm fluid. Therefore, warmed fluid resuscitation might be useful to perform immediate excision and grafting for the patients with extensive burns in acute burn shock.