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.     

严重烧伤后肠粘液成分变化与肠源性感染的关系

为探讨烧伤后回肠粘膜的病理变化,肠粘液及其中ＩｇＡ成分的变化及这些变化与肠源性感染的关系,我们利用小鼠制作ＴＢｓＡ２５％Ⅲ度烧伤模型,分别于伤后０．５、１、６、１２、２４小时观察;①小肠末端的病理病变;②测定小肠粘液层厚度及粘液中蛋白、己糖、唾液酸的含量;③检测粘液ＩｇＡ血清ＩｇＡ及粘膜固有层中分泌ＩｇＡ浆细胞数;④各时相小肠系膜淋巴结的细菌培养。结果表明：伤后小肠出现病理改变,粘液成分有变化,粘液中ＩｇＡ含量持续下降且与肠源性感染发生关系密切。     

严重烧伤后肠粘液成分变化与肠源性感染的关系

为探讨烧伤后回肠粘膜的病理变化,肠粘液及其中 IgA 成分的变化及这些变化与肠源性感染的关系,我们利用小鼠制作 TBsA 25%Ⅲ度烧伤模型,分别于伤后0.5、1、6、12、24小时观察;①小肠末端的病理病变;②测定小肠粘液层厚度及粘液中蛋白、己糖、唾液酸的含量;③检测粘液 IgA 血清 IgA及粘膜固有层中分泌 IgA 浆细胞数;④各时相小肠系膜淋巴结的细菌培养。结果表明:伤后小肠出现病理改变。粘液成分有变化,粘液中 IgA 含量持续下降且与肠源性感染发生关系密切。     

胆道梗阻及再通术后感染及与肠道细菌易位的关系

目的探讨胆道梗阻及再通后感染与肠道细菌易位的关系。方法分别对５１例胆道梗阻患者及３７例胆囊结石患者采用偶氮显色法测定门静脉血浆内毒素含量,同时行胆汁细菌培养及肠道菌群测定。结果胆道梗阻组肠道菌量及门静脉血浆内毒素含量较胆囊结石组明显升高（Ｐ＜０．０５）;此外,胆汁细菌培养５１例胆道梗阻患者中有４０例有菌生长（７８．４％）,与胆囊结石组（３２．４％）相比差异显著（Ｐ＜０．０１）。结论梗阻后胆道外引流及术后肠功能抑制均可诱发肠道细菌易位。胆道梗阻再通术后选用敏感抗生素行胆道冲洗,适当的胆道限流及促进胃肠蠕动,有助于维持胆道微生态环境的稳定,阻止肠源性内毒素入血,对防止肠道细菌易位,廓清术后胆道感染,改善预后具有非常重要的意义。     

胆道梗阻及再通术后感染与肠道细菌易位的关系

目的 探讨胆道梗阻及再通后感染与肠道细菌易位的关系。方法 分别对51例胆道梗阻患者及37例胆囊结石患者采用偶氮显色法测定门静脉血浆内毒素含量,同时行胆汁细菌培养及肠道菌群测定。结果 胆道梗阻组肠道菌量及门静脉血浆内毒素含量较胆囊结石组明显升高(P<0.05);此外,胆汁细菌培养51例胆道梗阻患者中有40例有菌生长(78.4%),与胆囊结石组(32.4%)相比差异显著(P<0.01)。结论 梗阻后胆道外引流及术后肠功能抑制均可诱发肠道细菌易位。胆道梗阻再通术后选用敏感抗生素行胆道冲洗,适当的胆道限流及促进胃肠蠕动,有助于维持胆道微生态环境的稳定,阻止肠源性内毒素入血,对防止肠道细菌易位,廓清术后胆道感染,改善预后具有非常重要的意义。     

The role of thermal injury on intestinal bacterial translocation and the mitigating role of probiotics: A review of animal and human studies

IntroductionBurn patients represent a combination of nutritionally deplete and calorically demanding individuals who are susceptible to morbidity and mortality. A source of sepsis in thermal injury patients is the gastrointestinal tract with its interaction of normal and potentially pathogenic bacteria. The normal flora of the intestines maintains the equilibrium of the gut and prevents bacterial translocation (BT) through numerous mechanisms, all of which are disrupted as a consequence of thermal injury. Probiotic supplements with varying strains of bacteria have the potential to stabilize the integrity of the gut lining and decrease the incidence of BT after thermal injury.MethodsA literature review was conducted for animal and human studies in English addressing probiotic therapy in thermal injury. Keywords, “probiotics,” “thermal injury” and “burn” were utilized. Reference lists for each analyzed article were also examined to ensure completeness of literature search. Each article was reviewed for methodology, results and conclusions.ResultsEleven and six unique articles were identified addressing probiotics in thermal injury in animal and human studies, respectively. Heterogeneity between studies and limited demographic and outcome reporting prevented meta-analysis and comprehensive recommendations to be formalized.ConclusionWhile heterogeneity did not allow for meta-analysis, the results overall suggest a preventative, if not therapeutic, potential for probiotics in patients after thermal injury. Despite initial concern that probiotic therapy could lead to systemic infection in immune compromised individuals, this was not observed in the analyzed studies. Numerous unanswered questions exist in regards to optimizing probiotic therapy in patients after thermal injury.     

头孢噻甲羧肟对烧伤后肠源性感染的预防作用

采用30%TBSA Ⅲ度烫伤大鼠模型,分不同时相(伤后3、6和12h)腹腔注射头孢噻甲羧肟,并通过血液、内脏和肠系膜淋巴结中细菌的定性和定量分析,评价头孢噻甲羧肟对预防烫伤大鼠绿脓杆菌肠源性感染的效果。结果表明,伤后3h 和6h 开始用药组,肠源性感染的发生率明显下降(分别为 P<0.001和 P<0.05),而伤后12h 开始用药组则无明显降低(P>0.05),但其肝、肾组织中的菌量也明显减少(P<0.01)。同时我们还动态观察了烫伤大鼠血液和内脏组织中药物的浓度,结果表明,用药后血、肝和小肠粘膜中能迅速达到有效药浓度,并维持4h 以上,但肠系膜淋巴结中未检测到药物。提示:大面积烧伤病人早期,短程使用有针对性的抗生素,对预防肠源性感染可能是有益的。     

头孢噻甲羧肟对烧伤后肠源性感染的预防作用

采用３０％ＴＢＳＡⅢ度烫伤大鼠模型，分不同时相（伤后３、６和１２ｈ）腹腔注射头孢噻甲羧肟，并通过血液、内脏和肠系膜淋巴结中细菌的定性和定量分析，评价头孢噻甲羧肟对预防烫伤大鼠绿脓杆菌肠源性感染的效果。结果表明，伤后３ｈ和６ｈ开始用药组，肠源性感染的发生率明显下降（分别为Ｐ＜０．００１和Ｐ＜０．０５），而伤后１２ｈ开始用药组则无明显降低（Ｐ＞０．０５），但其肝、肾组织中的菌量也明显减少（Ｐ＜０．０１）。同时我们还动态观察了烫伤大鼠血液和内脏组织中药物的浓度，结果表明，用药后血、肝和小肠粘膜中能迅速达到有效药浓度，并维持４ｈ以上，但肠系膜淋巴结中未检测到药物。提示：大面积烧伤病人早期，短程使用有针对性的抗生素，对预防肠源性感染可能是有益的。     

The effects of ketamine and propofol on bacterial translocation in rats after burn injury

BACKGROUND: Bacterial translocation (BT) occurs after thermal injury and may result from an ischemic intestinal insult. The aim of the study was to investigate the effects of ketamine and propofol as anesthetic agents on BT in an animal model of burn injury. METHODS: Sixty male Wistar Albino rats were randomly assigned to six groups of 10 rats each. Anesthesia was induced and maintained with ketamine in groups 1, 2 and 3 and with propofol in groups 4, 5 and 6 during 6 h. Groups 2, 3, 5 and 6 received 30% total body surface area (TBSA) third-degree burns. Groups 1 and 4 had no burn injury. Then, they were allowed to recover from the anesthesia at the end of 6 h. Mean arterial pressure (MAP) was monitored continuously and maintained within 10% of baseline (before burn injury) levels in all animals. Animals in groups 3 and 6 had a laparotomy to obtain a tissue sample from the terminal ileum for determination of intestinal lipid peroxidation by-product malondialdehyde (MDA) before (baseline) and 6 and 24 h after burn injury (ABI). So these animals were not included in the BT studies. At postburn 24 h, animals in groups 1, 2 and 4, 5 were sacrified and samples were taken from the mesenteric lymph nodes (MLN), liver and spleen for bacteriologic cultures. RESULTS: The incidence of BT was found to be significantly higher in group 2 than in all the other groups. Bacterial translocation incidence of group 5 was not significantly different from that of groups 4 and 1. Group 5 was associated with a significantly reduced number of enteric organisms per gram of tissue compared to group 2. Baseline MDA contents of groups 3 and 6 were similar. Ileal MDA levels were increased in group 3, but there were no significant changes in group 6 at 6 and 24 h ABI compared to baseline. CONCLUSION: Our results suggest that propofol as an anesthetic agent may prevent BT by scavenging reactive oxygen species and inhibiting lipid peroxidation in an animal model of burn injury.     

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.     

The role of poly(ADP-ribose) synthetase inhibition on the intestinal mucosal barrier after thermal injury

Oxidative and nitrosative stressor agents can trigger DNA strand breakage, which then activates the nuclear enzyme poly(ADP-ribose) synthetase (PARS). Activation of the enzyme depletes the intracellular concentration of energetic substrates such as nicotinamide adenine dinucleotide (NAD). This process can result in cell dysfunction and cell death. PARS inhibitors have been successfully used in ischemia–reperfusion injury, inflammation and sepsis in several experimental models. In our experimental study, we investigated the role of 3-aminobeanzamide (3-AB), a non-specific PARS inhibitor, on the intestinal mucosal barrier after burn injury. Twenty-four Wistar rats were randomly divided into three groups. The sham group (n = 8) was exposed to 21 °C water while the burn group (n = 8) and the burn + 3-AB group (n = 9) were exposed to boiling water for 12 s to produce a full thickness burn in 35–40% of total body surface area. In the burn + 3-AB group, 10 mg/kg of 3-AB was given intraperitoneally 10 min before thermal injury. Twenty-four hours later, tissue samples from mesenteric lymph nodes (MLN), spleen and liver were obtained under sterile conditions for microbiological analysis and ileum samples were obtained for biochemical and histopathological analysis. In burn group, the incidence of bacteria isolated from MLN and spleen was significantly higher than other groups (P < 0.05). 3-AB pre-treatment prevented burn induced bacterial translocation and it significantly reduced burn induced intestinal injury. Tissue malondialdehyde and 3-nitrotyrozine levels were found significantly lower than that of the burn group. These data suggest that the relationship between PARS pathway and lipid peroxidation in intestinal tissue and PARS has a role in intestinal injury caused by thermal injury.     

N-acetylcysteine attenuates bacterial translocation after partial hepatectomy in rats

BACKGROUND: Translocating enteric bacteria have been suggested as playing a major role in the development of infections after partial hepatectomy. We investigated the effect of N-acetylcysteine (NAC) on bacterial translocation (BT) and intestinal mucosa as the first line of defense against BT. MATERIALS AND METHODS: We compared four groups of eight Sprague-Dawley male rats each: sham, control (partially hepatectomized), partial hepatectomy plus preoperative single-dose NAC, and a fourth that received partial hepatectomy with a preoperative single-dose NAC plus treatment with NAC for 2 days. Microorganism counts of tissues, lung injury score, lung tissue glutathione, and malondialdehyde levels and microscopy of intestinal mucosa were studied at the end of 48 h. RESULTS: Microorganism count in the lung and mesenteric lymph node cultures and lung injury score were significantly higher in the control group when compared with the sham, third, and fourth groups (lung: 9919.6 versus 0.0, 2912.9, 1550.0 cfu/g tissue; mesenteric lymph nodes: 8458.3 versus 0.0, 89.0, 88.9 cfu/g tissue; lung injury score: 3.25 versus 0.5, 1.13, 1.75). In the control group, the villous height of the distal ileal mucosa was significantly shorter than the sham group (65.25 versus 75.25 microm) and the difference from groups 3 and 4 was not statistically significant. Neutrophil infiltration in the distal ileal mucosa of the control group was significantly higher than the sham, third and fourth groups (3.13 versus 0.25, 0.38 and 1.0). CONCLUSIONS: The parenteral use of NAC attenuates bacterial translocation after partial hepatectomy in rats. Attenuation of the lung injury after partial hepatectomy in NAC-treated groups might be attributable to both anti-inflammatory effect and the effect on BT.     

创伤及休克肠道细菌移位的研究

研究创伤失血性休克肠道细菌移位的发生率。设计兔创伤失血性休克试验模型，实验组３０只兔，腹部皮肤撕脱１００ｍｍ×９０ｍｍ，并行股动脉放血致休克，对照组１０只兔，腹部撕脱同实验组，不放血致休克。对照组术后１小时、３小时、５小时取标本均未发现肠道细菌移位，实验组术后１小时采标本已有肠道细菌移位，３小时、５小时组细菌移位达３０％。认为创伤失血性休克早期即有肠道细菌移位，并讨论了其临床意义     

Tempol reduces bacterial translocation after ischemia/reperfusion injury in a rat model of superior mesenteric artery occlusion

Purpose  We investigated whether Tempol, a water-soluble antioxidant, prevents the harmful effects of superior mesenteric ischemia/reperfusion on intestinal tissues in rats. Methods  The rats were divided into three groups of 10. In group 1, the superior mesenteric artery (SMA) was isolated but not occluded, and in groups 2 and 3 the superior mesenteric artery was occluded for 60 min. After that, the clamp was removed and reperfusion began. In group 3, 5 min before the start of reperfusion, a bolus dose of 30 mg/kg Tempol was administered intravenously and continued at a dose of 30 mg/kg for 60 min. All animals were euthanized after 24 h and tissue samples were collected for analysis. Results  There was a significant increase in myeloperoxidase activity, malondialdehyde levels, and the incidence of bacterial translocation in group 2, with a decrease in glutathione levels. These parameters were found to be normalized in group 3. The intestinal mucosal injury score in group 2 was significantly higher than those in groups 1 and 3. Conclusion  Tempol prevents bacterial translocation while precluding the harmful effects of ischemia/reperfusion injury on intestinal tissues in a rat model of superior mesenteric artery occlusion.     

静脉注射内毒素法制作大鼠肠道细菌易位模型

目的探讨静脉注射内毒素制作大鼠肠道细菌易位模型的方法。方法60只雄性SD大鼠(体重200～250g)随机分为4组(15只/组)。其中3组为实验组,按组别不同分别给予尾静脉注射内毒素2、4、6mg/kg;对照组给予尾静脉注射生理盐水0.5ml。观察各组大鼠的体温、呼吸频率、外周血白细胞计数及死亡率,7d后将各组大鼠分别开腹取门静脉血、下腔静脉血、肠系膜淋巴结、肝、脾和胰腺组织作细菌培养。结果注射内毒素后各组大鼠的体温、呼吸频率及外周血白细胞均有不同程度的升高。2mg/kg组大鼠无死亡,组织细菌培养阳性率为24.4%。4mg/kg组的死亡率为20.0%,细菌培养阳性率为47.2%,其中肠系膜淋巴结阳性率为83.3%。6mg/kg组的死亡率为46.7%,细菌培养阳性率为64.6%,其中肠系膜淋巴结阳性率为100.0%。结论4mg/kg剂量的内毒素静脉注射是制作大鼠肠道细菌易位模型的较为理想可行的方法。     

78例肝硬化患者肠道细菌易位及其相关性研究

目的了解肝硬化患者肠道细菌易位（BT）的发生率及其相关危险因素,分析BT与术后感染的关系。方法对77例肝移植和1例未行肝移植的肝硬化患者进行术中采样,取外周血、门脉血及肠系膜淋巴结（MLN）,分别进行需氧及厌氧培养,了解BT的发生率。结合术前、术后各种临床资料分析发生BT的危险因素及BT的临床意义。结果78例肝硬化患者中BT的发生率为10．3％（8／78）;细菌易位的部位以MLN为主,占5／8,发生BT的细菌主要是肠道G-兼性厌氧杆菌（55．6％）,其次为G^＋兼性厌氧球菌（22．2％）。BT组患者术前胆红素总量显著高于无BT组（P=0．022）;发生BT的患者其术后感染的风险是无BT患者的1．3倍。结论高胆红素血症是促发BT的独立危险因素,发生BT的肝移植患者术后感染的风险明显升高。     

失血性休克促进细胞移位的发生

目的 探讨失血性休克在细菌移位中的作用。方法 本组１００例患者分４组,对照组（Ｉ组）３４例;闭合性腹部钝伤致失血性休克组（Ⅱ组）２３例;闭合性腹部钝伤无失血性休克组（Ⅲ组）１５例;腹部内出血致失血性休克组（Ⅳ组）２８例;取患者手术前后的外周血、腹膜脏层拭子样品、术中门静脉血、回肠系膜淋巴结、肝活检组织进行需氧与厌氧培养。结果 细菌移位的发生率第Ｉ组为６％（２／３４）,第Ⅱ组６５％（１５／２３）。第     

Effects of two fluid resuscitations on the bacterial translocation and inflammatory response of small intestine in rats with hemorrhagic shock

Objective： To investigate the effects of two fluid resuscitations on the bacterial translocation and the inflammatory factors of small intestine in rats with hemorrhagic shock. Methods： Fifty SD healthy male rats were randomly divided into 5 groups （ n = 10 per group） ： Group A （ Sham group）, Group B （ Ringer＇ s solution for 1 h ）, Group C （Ringer＇ s solution for 24 h ）, Group D （ hydroxyethyl starch for 1 h ） and Group E （（ hydroxyethyl starch for 24 h）. A model of rats with hemorrhagic shock was established. The bacterial translocation in liver, content of tumor necrosis factor-α （TNF-α） and changes of myeloperoxidase enzyme （MPO） activities in small intestine were pathologically investigated after these two fluid resuscitations, respectively. Results ： The bacterial translocation and the expression of TNF-α in the small intestine were detected at 1 h and 24 h after fluid resuscitation. There were significant increase in the number of translocated bacteria, TNF-α and MPO activities in Group C compared with Group B, significant decrease in Group E compared with Group D and in Group B compared with Group D. The number of translocated bacteria and TNF-α expression significantly decreased in Group E as compared with Group C. Conclusions： The bacterial translocation and the expression of TNF-α in the small intestine exist 24 h after fluid resuscitation. 6 % hydroxyethyl starch can improve the intestinal mucosa barrier function better than the Ringer＇ s solution.     

Bacterial translocation induces proinflammatory responses and is associated with early death in experimental severe injury

Objective

An experimental model of severe injury with great lethality was studied to define the impact of bacterial translocation on survival and on inflammatory response.

Methods

Forty-one rabbits were divided into two groups: A, femur myotomy; and B, myotomy and fracture of the femoral bone. Vital signs and survival were recorded. Serum circulating endotoxins (lipopolysaccharides; LPS) were determined and tissue cultures were performed at necropsy. A subgroup of animals was sacrificed at 48 h post injury; LPS was determined in abdominal aorta and portal vein, apoptosis of spleen cells was assessed by flow cytometry, and ex vivo production of tumor necrosis factor alpha by splenocytes was measured.

Results

Tissue bacterial burden was increased in animals that died early (i.e., within 48 h after injury) versus rabbits that died later. Portal vein LPS at 48 h was increased in group B compared with group A, whereas circulating LPS did not differ. No difference in apoptosis of either lymphocytes or macrophages of the spleen was found in group B compared with group A. Following stimulation with LPS or phytohemagglutinin, tumor necrosis factor α production by splenocytes of group B was greater than that of group A.

Conclusions

Bacterial translocation primes enhanced proinflammatory responses and it is associated with early death in severe trauma.     

实验性梗阻性黄疸肠道细菌易位及精氨酸治疗的研究

目的观察梗阻性黄疸（梗黄）大鼠肠道细菌易位状况及经胃肠道给予精氨酸对肠道细菌易位的影响。方法结扎Wistar大鼠胆管，制成梗黄模型，60只Wistar大鼠随机分为假手术组、梗黄组和梗黄＋精氨酸治疗组，每组各20只，于术后21d观察并比较各组血浆内毒素、肿瘤坏死因子-α（TNF-α）、白细胞介素6（IL-6）的含量及肝功能状况，并对肠系膜淋巴结、胰腺及肺组织行细菌培养，末端小肠做病理检查。结果梗黄组大鼠血浆内毒素、TNF-α、IL-6含量、总胆红素及谷丙转氨酶均明显升高，肠系膜淋巴结、胰及肺组织细菌培养阳性率明显升高，小肠黏膜损伤严重，而精氨酸治疗组以上血清学指标较梗黄组均显著下降，肠系膜淋巴结、胰及肺组织细菌培养阳性率明显降低，小肠黏膜病理损害程度明显减轻。结论梗黄后出现的高内毒素血症与肠道细菌易位关系密切。精氨酸治疗可减轻梗黄时肠道细菌易位，从而降低血浆内毒素水平及细胞因子的过表达。