烧伤早期肠道喂(营)养的几个问题

提出了早期肠道喂养与营养的含义、共同点及不同点。烧伤早期肠道喂（营养）可维护肠道结构、功能、降低伤后高代谢。早期肠道喂（营养）的机制至少有三；（１）减轻肠道损伤，改善胃肠道血流，减轻缺血再灌注损伤；（２）减少肠道内毒素移位，调理枯否细胞活化；（３）降低体内介质、激素水平。     

紧密连接蛋白与烧伤后肠道屏障功能障碍研究进展

紧密连接(tight junction)是维护肠道屏障功能的主要因素.严重烧伤后多种原因可破坏肠上皮紧密连接,引起肠道屏障功能损害,细菌和(或)内毒素入血,引发肠源性感染、全身性炎症反应、MODS或MOF等.了解紧密连接在烧伤后肠道屏障功能障碍中的作用,可为今后防治工作提供新思路.     

γ干扰素与肿瘤坏死因子α对肠上皮屏障功能影响的实验研究

Objective To investigate the effect of combination of interferon-gamma (IFN-γ) and tumor necrosis factor-alpha ( TNF-α ) on intestinal epithelial barrier function. Methods The Caco-2 monolayers were cultured in DMEM nutrient solution, and then they were inoculated in 24-well or 6-well plate with Transwell inserts. They were divided into control group ( ordinary treatment), IFN-γ group ( with addition of 10 ng/mL IFN-γ), TNF-α group (with addition of 10 ng/mL TNF-α), and IFN-γ plus TNF-α group (with addition of 10 ng/mL TNF-α and 10 ng/mL IFN-γ ). Monolayers inoculated in 24-well plate were collected for determination of transepithelial electrical resistance (TER) with an ohmmeter at post treatment hour (PTH) 0, 6, 12, 24, 36, and 48, the permeability of monolayers with fluorescein isothiocyahate-labeled dextran (FITC-dextran) tracer method at PTH 48, the distribution and morphological change of tight junction occludin with immunofluorescence assay at PTH 48. Monolayers inoculated in 6-well plate were collected for determination of protein expression of occludin, myosin light chain kinase (MLCK), and phosphorylated MLC (pMLC) with Western blot at PTH 24. Data were processed with one-way analysis of vaiiance and t test. Results ( 1 ) There was no obvious difference in TER in control group at each time point ( F = 0. 86, P ＞ 0.05 ). TER in IFN-γgroup and TNF-α group were gradually decreased during PTH 6-48,but showed no statistical difference as compared with that at PTH 0 ( with F value respectively 1.69, 2.47,P values all above 0.05 ). TER in IFN-γplus TNF-α group was significantly decreased from PTH 24 as compared with that at PTH0 ( t =4.97, P ＜0.05) and that in each of the other three groups ( F =11.54,P ＜ 0.05 ). (2) The permeability of monolayers in IFN-γplus TNF-α group [( 1197 ± 215 ) pmol] was significantly higher than that in control group, IFN-γ group, and TNF-α group [( 303 ± 93 ), ( 328 ± 76),(797 ± 177) pmol, with t value respectively 4.8, 5.0, 6.9, P values all below 0.01]. (3) There was no statistical difference in occludin expression at PTH 24 among four groups ( F = 0.26, P ＞ 0.05). The occludin in control group at PTH 48 was regular in arrangement, while that in IFN-γand TNF-α groups was irregular in arrangement. The arrangement of occludin in IFN-γ plus TNF-c group at PTH 48 was interrupted,with obvious redistribution in cytoplasm. (4) The protein expression of pMLC in IFN-γ plus TNF-α group (0.95 ±0.05) was significantly higher than that in control group, IFN-γ group, or TNF-α group (0.57 ±0.12, 0.56 ±0.07, 0.59 ±0. 10, respectively, F = 17.97, P ＜0.01). The protein expression of MLCK in IFN-γplus TNF-α group (1.57 ±0.36) was also significantly higher than that in control, IFN-γ, TNF-α groups (0.85 ± 0.18, 1.04 ± 0. 23, 1.00 ± 0.07, respectively, F = 9.05, P ＜ 0.05 ). Conclusions Combination of IFN-γand TNF-α can induce intestinal epithelial barrier dysfunction by up-regulating MLCK protein expression and promoting MLC phosphorylation.     

严重烧伤后肠黏膜肌球蛋白轻链磷酸化表达改变及其意义

目的探讨肌球蛋白轻链（myosin light chain,MLC）磷酸化在严重烧伤早期对肠黏膜屏障功能及细胞紧密连接相关蛋白变化的作用。方法健康成年SD大鼠48只,采用随机数字表法分为正常对照组及烧伤后1、2、6、12、24h组,用异硫氰酸荧光素．葡聚糖（FITC-Dextran）检测大鼠肠黏膜通透性,免疫荧光法检测肠黏膜细胞紧密连接相关蛋白ZO-1、F-肌动蛋白（F．actin）及磷酸化型MLC（phosphorylated MLC,p-MLC）的变化。结果烧伤后大鼠肠黏膜通透性明显增加,伤后6h达高峰,为对照组的3倍（P〈0．01）;烧伤后肠上皮通透性的增加伴随有紧密连接相关蛋白ZO-1的明显重分布、细胞紧密连接损害以及肠上皮细胞p-MLC表达的增加。结论MLC磷酸化可能在严重烧伤后肠黏膜屏障功能紊乱及通透性增加的发生机制中起着重要的调控作用。     

腰-硬联合麻醉不同穿刺间隙在剖宫产术中的麻醉效果观察

目的研究在剖宫产手术中应用不同穿刺间隙进行腰-硬联合麻醉对产妇的影响。方法148例剖宫产行腰-硬联合麻醉产妇,依据病历单双号分为研究1组和研究2组,每组74例。研究1组给予L3~4间隙穿刺,研究2组给予L2~3间隙穿刺。对比两组麻醉效果,运动阻滞起效、感觉阻滞起效及感觉恢复时间,不良反应发生情况及麻醉平面上升情况。结果研究2组麻醉总有效率为91.89%,高于研究1组的79.73%,差异具有统计学意义(P<0.05)。研究2组麻醉后运动阻滞起效时间、感觉阻滞起效时间及感觉恢复时间均短于研究1组,差异具有统计学意义(P<0.05)。研究2组不良反应发生率为8.11%,低于研究1组的21.62%,差异具有统计学意义(P<0.05)。研究1组麻醉平面上升至T(7.18±1.95)节段,高于研究2组的T(5.06±2.03)节段,差异具有统计学意义(t=6.479,P<0.05)。结论在剖宫产手术腰-硬联合麻醉中对产妇实施L2~3间隙穿刺,其麻醉效果、起效及恢复时间、不良反应发生率及麻醉平面上升节段均优于L3~4间隙穿刺,值得推广。