小红参醌抑制烫伤小鼠肠道细菌易位

近年来,创伤后肠道细菌易位引起的内源性感染日益受到重视。为了探讨细菌易位的机制,本文采用具有一定的抗氧化作用并能减轻自由基损伤、改善PMN功能的小红参醌进行试验。试验分为两组,Ⅰ组26只Balb/C小鼠管饲小红参醌液(5mg/ml)0.5ml三天,Ⅱ组21只Balb/c小鼠管饲无菌蒸馏水0.5ml三天,而后行25％Ⅲ°烫伤。伤后24小时处死,观察细菌易位发生率,回肠MDA和SOD含量,及病理组织学改变。观察的结果为:Ⅰ组肠道细菌易位至MLN发生率为15.4％,Ⅱ组为57.14％,两者相比有显著性差异(P<0.01)。Ⅰ组MDA含量为7.25±1.74n mol/克蛋白,Ⅱ组为11.00±1.74n mol/克蛋白,两者有显著性差异(P<0.01),但SOD含量无统计学意义。病理形态观察支持了上述结果。提示小红参醌具有抑制伤后小鼠肠道细菌易位的作用。     

小鼠的免疫缺陷在其烫伤后引起肠道细菌易位的实验分析

近年来,创伤后肠道细菌易位引起的内源性感染日益受到重视。为了探讨细菌易位时免疫功能的作用,本文采用20%Ⅲ°烫伤的 T 细胞、NK 细胞,B 细胞免疫功能缺陷的与免疫功能正常的杂合子 SpF 小鼠进行实验,观察免疫功能缺陷时,伤后3个时相点中肠道细菌易位发生率,肠道微生态,回肠 MDA 和病理形态改变。获得;在肠道微生态未有改变,肠粘膜发生损伤的情况下,T 细胞和 NK 细咆免疫功能缺陷时,烫伤能促进肠道细菌易位,B 细胞免疫缺陷和免疫功能正常小鼠烫伤未发生肠道细菌易位。从机体的特异性和非特异性免疫的角度,对肠道正常菌丛易位引起的内源性感染进行了讨论。     

烧伤后免疫抑制引起肠道细菌易位和脓毒症的病理学研究

近年来,创伤后体内细菌易位造成的内源性感染逐渐受到重视,为了探讨细菌易位的条件和途径等机理。本文利用烧伤后注射大剂量地塞米松的大鼠动物模型,模拟烧伤后应激状态下体内肾上腺皮质激素分泌增多,免疫机能下降的条件,观察肠道和其它脏器的病理改变。观察结果证实,烧伤与大剂量皮质激素确有引起肠道细菌易位和内源性感染,造成脓毒症的叠加作用。其基本条件包括肠道菌群微生态平衡的改变,宿主免疫机能下降和肠粘膜屏障的破坏。易位的肠道细菌主要是通过肠粘膜的坏死灶,上皮细胞坏变缺损处进入肠粘膜淋巴管和小静脉的。超微结构改变包括肠上皮细胞表面的微绒毛倒伏、变形、脱落、上皮细胞顶端崩解破坏,细胞间隙泡状增宽。脓肿中多数细菌微细结构完好,粒细胞和吞噬细胞胞浆中有多量糖元颗粒聚集,提示糖皮质激素可能影响吞噬细胞的糖代谢而降低其吞噬功能,使易位的细菌得以定植形成脓肿感染。     

神经降压素对失血-感染大鼠肠道细菌易位的实验研究

目的：探讨神经降压素（Neurotensin,NT)对肠道细菌易位（Bacterialtranslocation,BT)的影响。方法：80只Wistar大鼠随机分成假手术组,单纯失血组,单纯感染组,失血－感染组及NT1,NT2,NT37个组,NT组均先制成失血－感染模型。然后分别用NT,10μg/kg,NT3 90μg/kg皮下注射,3h后取各组肝,肠系膜淋巴结（mesenteric Lymph node,MLN)制成匀浆进行细菌培养,抽门静脉血测定血内毒素水平,7组均取未段回肠1cm进行光镜和电镜检查。结果：除NT1外,失血－感染组BT率,组织细菌低;病理结构显示：NT1,NT2,NT3组肠粘膜受损伤较单纯失血,单纯感染,失血感染组均轻,有统计学差异。结论：NT能加速损肠粘膜修复,增强小肠粘膜屏障功能,阻止细菌易位,NT作用呈剂量依赖关系。     

四君子汤对免疫抑制小鼠肝脏细菌易位的影响

目的观察四君子汤对免疫抑制小鼠免疫功能及肝脏细菌易位的影响,探讨神经-内分泌-代谢-微生态-免疫网络之间的关系。方法应用氢化可的松制备小鼠免疫功能抑制模型,造成肝脏细菌易位;观察四君子汤对小鼠吞噬细胞功能的影响和细菌易位的控制,同时设自然恢复组和正常对照组进行比较。结果氢化可的松灌喂3d后,小鼠吞噬细胞的吞噬功能明显下降,肝脏出现大量细菌易位;经四君子汤治疗6h后,小鼠吞噬细胞吞噬功能显著提高。肝脏细菌易位明显减少。结论四君子汤能有效地控制免疫抑制小鼠肝脏细菌易位。     

青霉素促使烫伤SPF大鼠肠道细菌易位的研究

本文描述了在控制微生物实验动物实验室中,口服青霉素的SPF大鼠(n=10),25％Ⅲ°烫伤后出现的肠道细菌易位。该组大鼠盲肠和结肠中的乳酸杆菌数量显著下降(约1,000倍),而肠杆菌数量明显上升(约100倍以上),其MLN中的细菌易位发生率为9/10,肝、脾、肾、肺和血流的发生率为1/10。口服青霉素组大鼠(n=5)的MLN细菌易位发生率为2/5,其它器官细菌培养阴性。空白组(n=6)和烫伤组(n=6)大鼠均未出现肠道细菌易位。这些结果说明:抗生素促使了烫伤SpF大鼠肠道细菌的易位。据病理形态学的观察,讨论了肠道细菌易位发生的机理和易位的途径。     

大剂量顺铂所致大鼠急性肾衰过程中肠道细菌易位与肠内菌群比例变化的关系

目的研究大剂量顺铂(cisplatin,DDP)所致大鼠急性肾功能衰竭过程中肠道细菌易位与肠内菌群比例变化的关系。方法SD大鼠24只,雌雄各半,依体重随机分为DDP用药后24、48、72 h组和NS对照组,每组6只。10 mg/kg DDP单次腹腔内注射,等量生理盐水对照。随后观察并记录大鼠用药后的表现及体重变化情况;DDP用药后不同时间点分别取用药组大鼠和对照组大鼠,称重后内眦静脉取血,生化法检测血清尿素氮和肌酐的浓度;无菌条件下剖腹取回盲部淋巴结进行细菌培养;同时取十二指肠、空肠、回肠和结肠段内容物进行细菌涂片检查。结果大剂量DDP用药后6 h大鼠体重开始降低,用药48 h后出现腹泻症状并进行性加重。DDP用药后48 h大鼠出现血尿素氮、肌酐的比例显著升高,与对照组比较差异有非常显著性(P0.01)。DDP用药后24 h66%的大鼠回盲部淋巴结出现革兰阴性菌生长,用药后48 h革兰阴性菌生长的阳性率为83%,而对照组大鼠则无细菌生长。对照组大鼠十二指肠、空肠和回肠内主要以革兰阳性球菌为主,结肠内主要以革兰阴性杆菌和革兰阳性球菌为主。DDP用药后24 h,十二指肠、空肠、回肠和结肠内仍然以革兰阳性球菌为主;用药48 h后,空肠、回肠和结肠内革兰阴性杆菌所占比例逐渐增加。结论大剂量DDP可导致大鼠肠道细菌易位、空肠、回肠和结肠内菌群比例失衡,可能与大鼠内毒素血症及急性肾功能衰竭的发生、发展及恶化有关。     

成纤维细胞生长因子信号在骨损伤修复中的作用

骨损伤是常见的骨外科疾病。许多复杂的骨缺损,如创伤性大块骨缺损等常导致骨折延迟愈合及骨不连,是临床治疗中的难题。组织工程方法的运用为骨不连等的治疗提供了新的契机。成纤维细胞生长因子(fibroblast growth factor, FGF)信号在骨骼发育过程中发挥重要作用。基于其家族成员在骨折愈合过程中的时空表达及相关基因工程小鼠的表型,FGF信号相关分子被认为是骨再生修复的重要调节分子。该文将对FGF信号在骨损伤修复中的作用及应用方面的研究进展做综述,以期为其临床应用提供借鉴与参考。     

正常及损伤后修复的内皮细胞合成的蛋白聚糖

用自制尼龙刷将培养至汇合的人脐静脉内皮细胞刮伤后,造成规则的内皮细胞缺失区。继续培养可见,原有的内皮钿胞很快迁移到缺失区,并分裂增殖。约48小时新生的内皮细胞即将缺失区全部修复而形成新的汇合单层。以DEAE-Sephacel离子交换及Sepharose 6B凝胶过滤柱层析分析损伤后修复的内皮细胞合成的蛋白聚糖时发现所合成的蛋白聚糖总量减少;硫酸乙酰肝素蛋白聚糖合成相对减少、而硫酸软骨素及/或硫酸皮肤素蛋白聚糖合成相对增多。说明:伴随着内皮细胞的损伤后修复其蛋白聚糖的合成也有质和量的改变。     

四君子汤治疗功能性消化不良的临床疗效分析

目的:分析四君子汤治疗功能性消化不良的疗效及对患者生活质量的影响。方法:以2013年1月至2015年12月西安高新医院诊治的132例功能性消化不良患者为研究对象,将其根据就诊顺序分为观察组和对照组,每组66例,对照组给予奥美拉唑肠溶片和多潘立酮片治疗,观察组在对照组的基础之上给予四君子汤加减治疗。比较两组的临床疗效,血清胃动素(MTL)、胃泌素(GAS)、5-羟色胺(5-HT)及血管活性肠肽(VIP)水平以及生活质量评分。结果:治疗后,观察组的总有效率为93.94%,显著高于对照组的78.79%(P0.05)。治疗后,两组的中医症状积分均较治疗前显著降低(P0.05),且观察组显著低于对照组(P0.05)。观察组治疗后的MTL、GAS水平、生理功能(PF)、社会功能(SP)、生理职能(RP)、情感职能(RE)、躯体疼痛(BP)、活力(VT)、精神健康(MH)和总体健康(GH)评分均较治疗前显著升高(P0.05),且明显高于对照组(P0.05),5-HT及VIP较治疗前显著降低(P0.05),且低于对照组(P0.05)。结论:四君子汤加减治疗功能性消化不良的临床疗效显著,并可有效提高患者的生活质量,可能与其调节血清MTL、GAS、5-HT、VIP水平有关。     

Influence of fracture gap size on the pattern of long bone healing: a computational study

Following fractures, bones restore their original structural integrity through a complex process in which several cellular events are involved. Among other factors, this process is highly influenced by the mechanical environment of the fracture site. In this study, we present a mathematical model to simulate the effect of mechanical stimuli on most of the cellular processes that occur during fracture healing, namely proliferation, migration and differentiation. On the basis of these three processes, the model then simulates the evolution of geometry, distributions of cell types and elastic properties inside a healing fracture. The three processes were implemented in a Finite Element code as a combination of three coupled analysis stages: a biphasic, a diffusion and a thermoelastic step. We tested the mechano-biological regulatory model thus created by simulating the healing patterns of fractures with different gap sizes and different mechanical stimuli. The callus geometry, tissue differentiation patterns and fracture stiffness predicted by the model were similar to experimental observations for every analysed situation.     

Dysfunctional stem and progenitor cells impair fracture healing with age

Successful fracture healing requires the simultaneous regeneration of both the bone and vasculature; mesenchymal stem cells(MSCs) are directed to replace the bone tissue, while endothelial progenitor cells(EPCs) form the new vasculature that supplies blood to the fracture site. In the elderly, the healing process is slowed, partly due to decreased regenerative function of these stem and progenitor cells. MSCs from older individuals are impaired with regard to cell number, proliferative capacity, ability to migrate, and osteochondrogenic differentiation potential. The proliferation, migration and function of EPCs are also compromised with advanced age. Although the reasons for cellular dysfunction with age are complex and multidimensional, reduced expression of growth factors, accumulation of oxidative damage from reactive oxygen species,and altered signaling of the Sirtuin-1 pathway are contributing factors to aging at the cellular level of both MSCs and EPCs. Because of these geriatric-specific issues, effective treatment for fracture repair may require new therapeutic techniques to restore cellular function. Some suggested directions for potential treatments include cellular therapies, pharmacological agents, treatments targeting age-related molecular mechanisms, and physical therapeutics.Advanced age is the primary risk factor for a fracture, due to the low bone mass and inferior bone quality associated with aging; a better understanding of the dysfunctional behavior of the aging cell will provide a foundation for new treatments to decrease healing time and reduce the development of complications during the extended recovery from fracture healing in the elderly.     

Mallotus philippinensis bark extracts promote preferential migration of mesenchymal stem cells and improve wound healing in mice

In the present study, we report the effects of the ethanol extract from Mallotus philippinensis bark (EMPB) on mesenchymal stem cell (MSC) proliferation, migration, and wound healing in vitro and in a mouse model. Chemotaxis assays demonstrated that EMPB acted an MSC chemoattractant and that the main chemotactic activity of EMPB may be due to the effects of cinnamtannin B-1. Flow cytometric analysis of peripheral blood mononuclear cells in EMPB-injected mice indicated that EMPB enhanced the mobilization of endogenous MSCs into blood circulation. Bioluminescent whole-animal imaging of luciferase-expressing MSCs revealed that EMPB augmented the homing of MSCs to wounds. In addition, the efficacy of EMPB on migration of MSCs was higher than that of other skin cell types, and EMPB treatment improved of wound healing in a diabetic mouse model. The histopathological characteristics demonstrated that the effects of EMPB treatment resembled MSC-induced tissue repair. Taken together, these results suggested that EMPB activated the mobilization and homing of MSCs to wounds and that enhancement of MSC migration may improve wound healing.     

Simulation of fracture healing incorporating mechanoregulation of tissue differentiation and dispersal/proliferation of cells

Modelling the course of healing of a long bone subjected to loading has been the subject of several investigations. These have succeeded in predicting the differentiation of tissues in the callus in response to a static mechanical load and the diffusion of biological factors. In this paper an approach is presented which includes both mechanoregulation of tissue differentiation and the diffusion and proliferation of cell populations (mesenchymal stem cells, fibroblasts, chondrocytes, and osteoblasts). This is achieved in a three-dimensional poroelastic finite element model which, being poroelastic, can model the effect of the frequency of dynamic loading. Given the number of parameters involved in the simulation, a parameter variation study is reported, and final parameters are selected based on comparison with an in vivo experiment. The model predicts that asymmetric loading creates an asymmetric distribution of tissues in the callus, but only for high bending moments. Furthermore the frequency of loading is predicted to have an effect. In conclusion, a numerical algorithm is presented incorporating both mechanoregulation and evolution of cell populations, and it proves capable of predicting realistic difference in bone healing in a 3D fracture callus.     

Novel fabrication of morphology tailored nanostructures with Gelatin/Chitosan Co-polymeric bio-composited hydrogel system to accelerate bone fracture healing and hard tissue nursing care management

In this study, we are successfully fabricated on a hydrogel consisting of TiO₂ nanoparticles loaded onto a gelatin/chitosan matrix to control the acceleration of bone fracture healing and improved the nursing care applications. Each specimen (chitosan, gelatin and titanium dioxide) were characterized and confirmed by using different techniques, Fourier transforms infrared spectroscopy, X-ray diffraction analysis, Scanning Electron Microscopy with Elemental dispersive X-ray analysis, Thermo-gravimetric and Differential thermal analysis. In addition, the cell cytotoxicity results verified that the TiO₂/gelatin-chitosan hydrogel are nontoxic to osteoblasts. And cell fixation outcome after 5 days of incubation condition revels that the enhanced in vitro cell survival and cell spreading on the prepared TiO₂ incorporated hydrogel with respect to gelatin/chitosan hydrogel. Furthermore, TiO₂/gelatin-chitosan hydrogel nanostructures can modulate the bone fracture healing, indicating a potential application on nursing care.