肠缺血再灌注对大鼠脑的影响

目的 评价肠缺血再灌注对大鼠脑的影响.方法 健康雄性成年SD大鼠64只,采用随机数字表法,将其随机分为2组(n=32):假手术组(S组)和肠缺血再灌注组(II/R组),采用Morris水迷宫实验测定认知功能,随后II/R组采用夹闭肠系膜上动脉90min后再灌注的方法制备肠缺血再灌注模型,S组仅分离肠系膜上动脉,不夹闭.于再灌注2、6、12、24 h时各组随机取8只大鼠,经心脏取血2ml后,取肠及脑组织,光镜下观察病理学结果,采用改良Chiu评分法评价肠粘膜损伤程度,采用ELISA法测定血浆TNF-α和IL-6浓度,采用TUNEL法检测皮层脑组织细胞凋亡情况;于再灌注24 h时采用Morris水迷宫实验测试认知功能.结果 S组大鼠肠及脑组织镜下结构未见异常,II/R组再灌注6 h后可见明显肠道和脑损伤.与S组比较,II/R组再灌注2、6、12和24 h时Chiu评分、血浆TNF-α及IL-6浓度升高,再灌注6、12和24 h时细胞凋亡数增加,再灌注24 h时大鼠潜伏期、游泳距离增加,穿越平台次数减少(P＜0.05或0.01),游泳速度差异无统计学意义(P＞0.05).结论 肠缺血再灌注损伤可诱发大鼠脑损伤,引起认知功能减退,可能与炎性介质的释放及神经细胞凋亡有关.

Abstract：

Objective To investigate the effects of intestinal ischemia-reperfusion (I/R) on the brain in rats. Methods Sixty-four healthy male SD rats weighing 250-300 g were randomly allocated to one of 2 groups (n = 32 each): sham operation group (S) and intestinal I/R group (I/R). Intestinal I/R was produced by occlusion of superior mesenteric artery (SMA) for 90 min followed by reperfusion. Eight animals were sacrificed at each of the following time points: 2, 6, 12 and 24 h of reperfusion (T1-4) in each group. After a median sternotomyblood samples were taken from left ventricle for measurement of plasma TNF-α and IL-6 (by ELISA). Intestine and brain tissue was harvested for microscopic examination and detection of apoptosis ( by TUNEL). The cognitive function was tested using Morris water maze at 24 h. Results No abnormality was found in intestine and brain tissue in group S. Intestinal damage and neurodegeneration were detected in group I/R. Intestinal I/R significantly increased cerebral apoptosis in group I/R compared with group S. Plasma TNF-a and IL-6 concentrations were significantly higher at T1-4 in group I/R than in group S. The escape latency and swimming distance were significantly increased, while the number of crossing the platform was decreased in group I/R compared with group S. There was no significant difference in the swimming speed between the 2 groups. Conclusion Intestinal I/R can induce brain injury and lead to cognitive dysfunction. I/R-induced release of inflammatory mediators and neuronal apoptosis are involved in the underlying mechanism.     

15-F2t-isoprostane在大鼠肠缺血再灌注损伤中的作用

目的 评价异构前列腺素15-F2t-isoprostane在大鼠肠缺血再灌注损伤中的作用.方法 健康雄性SD大鼠32只,体重230 ～ 255 g,采用随机数字表法,将其随机分为4组(n=8):假手术组(S组)、肠缺血再灌注组(I/R组)、血栓烷A2(TXA2)受体拮抗剂SQ-29548组(SQ组)和二甲基亚砜组(DMSO组).采用阻断肠系膜上动脉60 min,再灌注120 min的方法制备肠缺血再灌注损伤模型.SQ组及DMSO组分别于夹闭肠系膜上动脉前30 min腹部皮下注射SQ-29548或二甲基亚砜2μmol/kg.于再灌注120 min时取肠段,观察肠粘膜形态学,并行Chiu评分,取肠粘膜组织,检测髓过氧化物酶(MPO)、超氧化物歧化酶(SOD)活性和丙二醛(MDA)、乳酸(LD)含量;采集动脉血样,检测血清二胺氧化酶( DAO)活性及15-F2t-isoprostane、内皮素-1(ET-1)和血栓烷B2(TXB2)浓度.结果 与S组比较,其余各组Chiu评分、DAO活性、15-F2t-isoprostane及TXB2浓度均升高(P＜0.05),SQ组LD和MDA含量、MPO和SOD活性及ET-1浓度差异无统计学意义(P＞0.05);与I/R组比较,SQ组Chiu评分、LD含量、DAO和MPO活性及ET-1浓度降低,SOD活性升高(P＜0.05).结论 15-F2t-isoprostane可通过激活TXA2受体,增加ET-1生成及促进中性粒细胞在肠粘膜聚集参与大鼠肠缺血再灌注损伤过程.     

充气式升温机复合多沙普仑对老年患者上腹部手术后复苏的影响

目的探讨充气式升温机复合多沙普仑对老年患者上腹部手术复苏的影响。方法选择100例60岁以上择期上腹部手术符合入选要求的患者作为研究对象,将其随机分为试验组及对照组,各50例。两组均采取常规的保暖,试验组另加充气式升温机保暖,并待患者能首次睁眼时即予单次静脉注射多沙普仑0.6mg/kg,于术后不同时段记录患者的体温、SPO2、心率、血压、睁眼时间、苏醒时间及在恢复室的停留时间。结果试验组在保暖后15、30、60、90min的体温比对照组回升快且恒定,效果优于对照组（P〈0.05）;睁眼时间、苏醒时间及在恢复室的停留时间显著短于对照组（P〈0.05）。结论老年患者上腹部手术后采用充气式升温机复合多沙普仑能缩短苏醒时间及患者在恢复室的停留时间。     

氟比洛芬酯复合不同剂量舒芬太尼用于胃肠外科患者术后静脉自控镇痛效果比较

目的观察氟比洛芬酯复合不同剂量舒芬太尼在胃肠手术患者静脉自控镇痛(PCIA)中的效果和安全性。方法选择ASAⅠ或Ⅱ级择期行胃肠外科手术患者100例,术后行PCIA,背景剂量2 ml/h,按压剂量2 ml/次,负荷量2 ml,锁定时间15 min,药液量100 ml分别含舒芬太尼150μg(A组)、舒芬太尼50μg+氟比洛芬酯200 mg(B组)、舒芬太尼100μg+氟比洛芬酯200 mg(C组)、舒芬太尼150μg+氟比洛芬酯200 mg(D组)。观察并记录术后即刻(T0)、2 h(T1)、4 h(T2)、12h(T3)、24 h(T4)患者镇痛评分(VAS)、Ramsay镇静评分、PCIA泵按压次数及不良反应。结果 C、D组在T2~T4时VAS评分和PCIA泵按压次数明显低于A、B组(P<0.05),T1~T3时B、C组Ramsay评分显著低于A、D组(P<0.05)。术后24 h内A、D组恶心的发生率明显高于B、C组(P<0.05)。结论氟比洛芬酯200 mg复合舒芬太尼100μg/ml静脉自控镇痛可为胃肠外科患者术后提供良好的镇痛效果且不良反应少。     

缺血预处理抗大鼠肠缺血再灌注肠黏膜损伤的蛋白质组学研究

目的采用蛋白质组研究技术分离、鉴定缺血预处理（IPC）抗大鼠肠缺血再灌注（Ⅱ／R）肠黏膜损伤相关蛋白,探讨其肠保护分子机制。方法将16只SD大鼠,随机分为Ⅱ／R组和IPC组。Ⅱ／R组阻断肠系膜上动脉60min后再开放60min;IPC组在阻断肠系膜上动脉前先阻断20min后再开放5min。余同Ⅱ／R组。再灌注结束即刻刮取肠黏膜,利用高分辨双向电泳对肠黏膜组织进行蛋白质分离．Image Master 2D Elite 5．0图像软件进行分析。应用基质辅助电离解析飞行时间质谱获取肽质量指纹图谱．检索数据库鉴定表达差异的蛋白质,明确其生物学功能。结果双向电泳发现,Ⅱ／R组及IPC组分别有蛋白质点（1404±20）个和（1338±20）个。10个点进行质谱分析,8个蛋白质点经过检索与已知蛋白质匹配．这些蛋白功能涉及到抗氧化、抑制凋亡及改善能量代谢。RT-PCR分析提示IPC上调醛糖还原酶的表达。Western blot分析提示IPC上调醛脱氢酶的表达。结论比较蛋白组学研究揭示IPC对肠缺血再灌注损伤的保护机制可能与其上调了一些具有抗氧化、抑制细胞凋亡及改善能量代谢作用的蛋白有关。     

羟乙基淀粉和琥珀酰明胶急性高容血液稀释对兔肾脏的影响

目的评价羟乙基淀粉(HES 200/0．5)和琥珀酰明胶急性高容血液稀释(AHHD)对兔肾组织形态学、超微结构和功能的影响。方法28只新西兰大白兔随机分成5组：对照组(C组,n= 4),20 ml-kg~(-1)琥珀酰明胶AHHD组(GA组)、20ml·kg~(-1)羟乙琏淀粉AHHD组(HA组)、33 ml·kg~(-1)琥珀酰明胶AHHD组(GB组)和33ml·kg~(-1)羟乙基淀粉AHHD组(HB组)(n=6)。C组不进行AHHD,GA组、HA组、GB组和HB组由颈内静脉以20ml·kg~(-1)·h~(-1)速率输入不同胶体液进行AHHD,静脉输注硝酸甘油,并根据血压和中心静脉压情况调节用量。在观察期间,每组以8ml·kg~(-1)·h~(-1)速率输入乳酸钠林格氏液。AHHD前5 min(T_0)、AHHD后15 min(T_1)、240 min(T_2)分别采集动脉血测血常规。进行血气分析及比色法测定血清肌酐和尿素氮浓度。T_2时处死动物,取右肾下极组织观察肾组织形态学及超微结掏的变化,进行肾组织Paller标准评分及空泡变性程度评分。结果各组血清肌酐和尿素氮浓度无明显改变。C组、GA组、GB组肾组织未见明显异常。HA组光镜显示肾组织未见明显异常,电镜显示局灶性肾小管上皮细胞混浊肿胀,线粒体嵴模糊；HB组光镜显示局灶性肾小管上皮变性,电镜显示少数肾小管上皮细胞空泡变性。HB组肾组织Paller标准评分及空泡变性程度评分高于其它各组(P＜0．01)：结论33ml．kg~(-1)羟乙基淀粉(HES 200/0．5)AHHD可引起兔肾小管超微结构改变,但肾功能未见明显改变；20、33 ml·kg~(-1)琥珀酰叫胶、20 ml·kg~(-1)羟乙基淀粉AHHD对兔肾脏无明显影响。     

四逆汤预先给药对大鼠肠缺血/再灌注所致急性肺损伤的作用

目的 研究四逆汤(SND)预先给药对大鼠肠缺血/再灌注(I/R)所致急性肺损伤的作用。方法 32只健康成年SD大鼠,雌雄不拘,随机分为4组:对照组(肠系膜上动脉仅分离而不阻断)、损伤组(肠系膜上动脉阻断1 h后再灌注3 h)、SND1 组(肠系膜上动脉阻断前3 d始连续经胃管灌入SND,总量为3 g/kg)、SND2组(肠系膜上动脉阻断前3d始连续经胃管灌入SND,总量为6 g/kg),每组8只。颈动脉插管监测平均动脉压(MAP)。每组动物均于再灌注3 h后断头处死。取肺组织测定肺通透性指数、肺组织一氧化氮(NO)、内皮素-1(ET-1)、丙二醛(MDA)的含量及超氧化物歧化酶(SOD)的活性,并在光镜下观察肺组织形态学的变化。结果 应用SND预先给药可明显减轻肠I/R引起的低血压和肺组织形态学改变。与对照组比较,损伤组肺通透性指数、肺含水率、肺组织MDA含量和NO含量显著性增高,而肺组织SOD活性显著性降低(P<0.01或0.05),两组肺组织ET-1含量无显著性差异。SND1组和SND2组肺组织SOD活性较损伤组显著性增高(P<0.01或0.05),但与对照组比较差异无显著性。结论 四逆汤预先给药通过抗氧化作用并减少NO的生成、维持NO/ET-1正常比例而减轻肠I/R引起的急性肺损伤。     

全麻原位肝移植患者术中酸碱及电解质浓度的变化

肝脏晚期病变导致的病理生理改变和手术创伤对机体的干扰 ,使机体围术期常出现严重的循环、电解质和酸碱紊乱。本文着重探讨原位肝移植术中不同时期患者血浆电解质及酸碱的变化及处理 ,以指导临床工作。1　对象和方法本组原位肝移植 2 3例 ,均系 2 0 0 1- 0 7～ 2 0 0 2 - 0 6在中山大学附属第一医院接受手术的晚期肝病患者。其中男 18例 ,女 5例 ,年龄 31～ 6 8岁 ,采用气管插管全身麻醉。诱导采用丙泊酚 2mg/ kg,芬太尼 3～ 5μg/ kg,维库溴胺 0 .1mg/ kg,维持为异氟醚或地氟醚吸入 ,芬太尼与维库溴胺间断静注。转流方法 :无肝期采用体外…     

麻醉药物对脑血流动力学的影响

健康成人的脑循环通过自身调节可为神经系统活动定量提供氧和葡萄糖,该自身调节会受术中麻醉用药的影响,进而改变脑的氧和能量供应.使用麻醉药物的同时控制颅内压(intracranial pressure,ICP)在正常范围,是手术安全的前提之一.颅内压由骨性颅腔的内容物,如脑组织、颅内血容量,脑脊液所决定.颅腔内容物在颅内静脉回流不受损的情况下.很大程度上取决于脑血流量(cerebral blood flow,CBF)以及脑脊液生成和吸收的平衡.麻醉药物通过多种机制改变脑血流量.     

缺血预处理-后处理对大鼠肠缺血再灌注损伤的影响

Objective To evaluate the effects of ischemic preconditioning-postconditioning on the intestinal ischemia-reperfusion (IR) injury in rats. Methods Forty healthy male SD weighing 225-275 g were randomly assigned into 5 groups ( n = 8 each): group I sham operation (group S) ; group II intestinal IR (group IIR); group Ⅲ ischemic preconditioning (group Ipr); group IV ischemic postconditioning (group Ipo); group V Ipr+ Ipo. The rats were anesthetized with intraperitonel 20% urethane 5 ml/kg. Superior mesenteric artery (SMA) was occluded for 60 min followed by 60 min reperfusion. In group S, SMA was isolated but not occluded. In group Ipr, SMA was occluded for 10 min followed by 10 min reperfusion, and the rest procedures were performed using the method described in group IIR. In group Ipo, 60 min ischemia was followed by three 30 s episodes of ischemia at 30 s intervals for reperfusion. In group Ipr+ Ipo, Ipr was performed followed by Ipo and the procedures were performed using the methods described in group Ipr and Ipo. The animals were killed at 60 min of reperfusion. The intestinal tissues were immediately removed for determination of MDA content, SOD and MPO activities and the degree of damage to intestinal mucous membrane was scored according to Chiu score. Arterial blood samples were taken for determination of plasma concentrations of TNF-α and 1L-6. Results Compared with group S, Chiu score, MDA content, MPO activity, and plasma concentrations of TNF-α and IL-6 were significantly increased, whereas SOD activity decreased in the other 4 groups ( P < 0.05). Chiu score, MDA content, MPO activity, and plasma concentrations of TNF-α and IL-6 were significantly decreased, whereas SOD activity increased in group Ipr, Ipo and Ipr + Ipo as compared with group IIR ( P < 0.05). Chiu score and MDA content were significantly lower, whereas SOD activity higher in group Ipr + Ipo than in group Ipr and Ipo ( P < 0.05). No significant differences were detected in the indices between group Ipr and group Ipo ( P > 0.05). Conclusion Ischemic preconditioning-postconditioning can attenuate the intestinal IR injury in rats, and the efficacy is better than that of either Ipr or Ipo alone.