獾油促进深Ⅱ度烫伤小鼠创面愈合作用的研究

目的:检测獾油对小鼠深Ⅱ度烫伤创面愈合的促进作用.方法:制备小鼠深Ⅱ度烫伤模型,分为烫伤对照组(A组)、植物油治疗组(B组)和獾油治疗组(C组).创面依次用生理盐水纱布、植物油纱布、獾油纱布覆盖.无菌纱布包扎固定,每日换药一次.于伤后7天、10天、15天按照Nagelschmidt法观察并记录创面愈合面积,计算创面愈合率;取创面组织,制成石蜡切片,观察病理及组织形态学变化.结果:獾油能加速烫伤创面的再上皮化,促进创面的愈合;提高烫伤组织细胞的增殖活性;促进烫伤创面表皮干细胞的增殖分化.结论:獾油对深Ⅱ度烫伤创面愈合有促进作用     

肝素促进深Ⅱ度烧伤小鼠bFGF及PDGF表达的研究

目的:探讨肝素对深Ⅱ度烧伤小鼠内源性碱性成纤维生长因子(bFGF)和血小板源生长因子(PDGF)表达的影响.方法:制作小鼠深Ⅱ度烫伤模型,肝素组用3000U/mL肝素外敷伤口2min,每日2次,观察创面愈合状况,并在给药后第3天分别从肝素组(烫伤后用肝素处理)、烫伤组(烫伤后自然愈合)及对照组(未进行烫伤处理)取5只小鼠处死,提取烫伤及其周围皮肤组织的蛋白质,用Western-blotting检测bFGF和PDGF的表达状况.结果:肝素组bFGF和PDGF表达均高于烫伤组;而烫伤组的两种生长因子的表达均高于对照组.结论:烫伤后bFGF和PDGF的表达量增高,且肝素能促进深Ⅱ度烧伤内源性生长因子bFGF、PDGF的表达.     

一种汽油混合燃料制作动物烧伤模型的方法研究

目的:探索实验室中大鼠不同程度烧伤模型建立的实验条件.方法:通过燃烧实验,确定汽油混合燃料成分配比;将30只SD大鼠随机分成6组,每组5只.选取背部作为烫伤部位.第1组为正常对照组,第2、3、4、5、6组为模型实验组,各组均涂抹适中混合燃料,烧伤时间分别持续15s,20 s,25 s,30s,40 s.烧伤后对局部组织进行形态和组织病理观察,观察有无毛囊、汗腺等附件受损.结果:重量百分比计为35％的常压渣油燃烧时间15秒为浅Ⅱ度烧伤,20-25秒为深Ⅱ度烧伤,30秒以上为Ⅲ度烧伤.结论:该模型可以较好地控制烧伤深度、面积,烧伤深度划分准确且操作简便,是研究烧伤修复机制及评价创面用药的较好模型.     

应用便携式数字化温控烫伤仪建立标准化大鼠皮肤烫伤模型

目的:研制一种新型便携式数字化温控烫伤仪,通过自制数字化烫伤仪对大鼠进行烫伤实验,建立标准化大鼠皮肤烫伤模型,从而验证数字化烫伤仪的有效及实用性。方法:选取18只SD大鼠分为对照组(3只,不烫伤);实验组(15只),再将实验组大鼠随机分配为A组(6只)、B组(6只)、C组(3只),选取大鼠背部作为烫伤实验部位:1、时间设定为20 s和30 s,烫伤仪温度分别设定为70℃、80℃、90℃、100℃、120℃,对A组和B组大鼠进行烫伤处理。2、温度设定为100℃,烫伤仪加热时间分别设定为10 s、15 s、25 s,对C组大鼠进行烫伤处理。烫伤后48 h切取实验组和对照组大鼠背部皮肤,进行大体及显微镜下组织病理学观察。结果:70℃20s烫伤点为I°烫伤;70℃30 s、80℃20 s、100℃10 s烫伤点为浅Ⅱ°烫伤;80℃30 s和100℃15 s烫伤点为深Ⅱ°烫伤;90℃20 s、90℃30 s、100℃20 s烫伤点为Ⅲ°烫伤;100℃25 s、100℃30 s、120℃20 s、120℃30 s烫伤点为IV°烫伤。结论:新型便携式数字化温控烫伤仪,可以可靠的建立标准化大鼠皮肤烫伤模型。     

烧烫伤创面感染的小鼠模型构建

目的探讨一种简单、稳定的烧烫伤创面感染的小鼠模型构建方法,以便进行相关烧烫伤创面修复研究。方法取30只BALB/c小鼠,采用自制木质烫伤板,沸水浴法烫取直径8 mm的圆形创面,烫伤时间分别为5 s、10 s、15 s。伤后48 h,取创面组织进行HE染色观察,筛选最佳创面烫伤时间。另取72只小鼠制成深Ⅱ度烫伤创面,采用擦刮法分别接种20μL菌浓度为1×106、l×107、1×108CFU/mL金黄色葡萄球菌标准菌株ATCC 25923的菌液。接种细菌后72 h,取创面组织HE染色观察创面炎症反应情况,并测定3、7、14 d的皮肤菌负荷,筛选最佳的细菌接种浓度。最后,按最佳条件建模后,观察创面的完全愈合时间以及创面愈中、愈后的组织学变化,以确定此创面感染模型是否建立成功。结果组织学结果表明,10 s为深Ⅱ度创面的理想致伤时间,最佳接种菌浓度为l×108CFU/mL,此时期,14 d内菌负荷均高于l×105CFU/g。该模型的创面愈合时间(21±0.95 d)较正常创面愈合时间(15.92±0.34 d)明显延长(P<0.01),炎性反应明显,愈后不佳。结论烧烫伤创面感染的小鼠模型构建成功,可作为感染创面防治研究的实验动物模型。     

仙人掌提取物对浅Ⅱ度烫伤治疗作用的研究

目的:探讨野生仙人掌提取物对浅Ⅱ度烫伤小鼠的治疗作用。方法:建立浅Ⅱ度烫伤小鼠模型,随机分为仙人掌提取物乙醇组A1,蒸馏水组A2和混合组A3(每组又分低、中、高3个浓度),烫伤(阴性)组B,药物(阳性)组C。每天涂药1次,观察、记录创面愈合情况,分别在5d和12d各组随机取5只小鼠做病理切片,观察并记录血管、纤维细胞、成纤维细胞等的数量,进行统计学分析。结果:①混合提取物中、高浓度组愈合时间,与烫伤组相比有显著性差异(p0.05、p0.01)。②5d时不同的仙人掌提取物组与烫伤组比,血管数量、成纤维细胞占总纤维细胞的百分含量都有差异(p0.05)。结论:野生仙人掌提取物能加速烫伤创面愈合,尤其对血管和成纤维细胞有显著的促进增生作用,并加速再上皮化。     

基于光学相干层析成像技术的鼠皮肤II度烫伤及其修复过程监控

建立小鼠皮肤的Ⅱ度烫伤的模型,分别于烫伤前、烫伤后1 min、8 h、1 d、3 d、5 d、7 d、9 d、11 d、13 d、15 d、17 d,用光学相干层析成像技术(OCT)对烫伤的创面进行动态的监测,同时对创面进行组织病理学的检测,对结果进行分析。利用OCT单次散射模型获得皮肤在烫伤前后光衰减系数的变化情况,结果显示光衰减系数的值在烫伤后是呈先减小后增大的趋势,待修复完全后又恢复到烫伤前相近的值。该结果与组织病理学的结果相吻合,这表明OCT技术可以用于实时诊断烫伤的皮肤。     

仙人掌提取物对浅Ⅱ度烫伤小鼠VEGF及FGF-2表达的影响

为探讨野生仙人掌和食用仙人掌提取物对浅Ⅱ度烫伤小鼠内源性血管内皮生长因子(VEGF)及碱性成纤维细胞生长因子(FGF-2)表达的影响,建立小鼠浅Ⅱ度烫伤模型。野生、食用仙人掌提取物组(浓度均为12.5 mg/mL),药物组(京万红),烫伤组(生理盐水),每天2次涂药并观察创面,分别在3 d和7 d各组取5只小鼠处死,取烫伤组织提取蛋白并检测VEGF、FGF-2的表达状况。仙人掌组中VEGF及FGF-2的表达量均高于烫伤组,且两种仙人掌组VEGF及FGF-2的表达量有差异。即仙人掌提取物能提高VEGF及FGF-2的表达量并能促进创面的修复。     

外源性VEGF促进大鼠Ⅱ度烫伤创面中晚期愈合

目的探究Ⅱ度烫伤时外源性血管内皮生长因子(vascular endothelial growth factor,VEGF)对皮肤愈合及其对表皮干细胞(epidermal stem cells,ESCs)迁移、分化的影响方法健康Wistar大鼠随机分为VEGF组、空白对照组、阿西替尼(Axitinib,VEGF抑制剂)组。采用水浴烫伤法制备Ⅱ度烫伤模型,分别以0.2μg/ml VEGF、PBS溶液和10μg/ml阿西替尼处理各组创面,各组均治疗7d,从烫伤至创面愈合分别在第2d、8d、14d及21d测量创面愈合情况,并取创面组织作组织学检测,运用免疫组化技术检测ECSs的分布及数量。结果①创面愈合率:烫伤后21d VEGF组>对照组>阿西替尼组;②愈合速度:烫伤后1-7d空白对照组>阿西替尼组>VEGF组,其后VEGF组愈合速度逐渐加快,第14d开始愈合速度表现为VEGF组>空白对照组>阿西替尼组;③组织学变化:烫伤后8-21d,VEGF组表皮细胞增殖明显,表皮修复和毛囊再生迅速,均早于空白对照组及阿西替尼组。④ECSs阳性细胞率变化:烫伤后第8-14dVEGF组ECSs阳性细胞率明显高于空白对照组和阿西替尼。结论Ⅱ度烫伤时,外源性VEGF在愈合中晚期加快愈合速度使愈合时间明显缩短,并且促进毛囊汗腺的再生使修复后的创面在外观、功能与正常皮肤相近,有助于提高全层皮肤创面的愈合质量。     

在烫伤条件下VEGF对大鼠皮肤eNOS基因表达的影响

目的:探讨大鼠烫伤愈合过程中VEGF对皮肤组织eNOS基因表达的影响。方法:采用了大鼠深II度烫伤模型,分别以VEGF和阿西替尼(VEGF抑制剂)干预,观察大鼠烫伤后愈合过程的组织学变化,PCR检测创面eNOS基因的表达。结果:肉眼观察VEGF组大鼠创面最早愈合,对照组大鼠愈合速度其次,阿西替尼组创面愈合最晚;HE染色结果显示伤后第2、8、21天VEGF组炎性细胞浸润程度、新生毛细血管数量均高于对照组和阿西替尼组,PCR结果显示烫伤后第2、8天VEGF组的eNOS基因的表达明显上调,且同时间点与对照组比较有统计学意义(P0.05)。结论:VEGF可诱导烫伤创面eNOS基因的表达,增加血管生成重要因子NO的生成,有利于创面愈合。     

Serum-derived exosomes accelerate scald wound healing in mice by optimizing cellular functions and promoting Akt phosphorylation

Wound exudate holds great clinical and research potential in wound repair via paracrine signaling. In essence, exudate is modified serum that contains a high concentration of exosomes. The aim of this study was to investigate the role of serum-derived exosomes in scald wound healing of NIH mice skin and to explore the underlying mechanisms. Hence, we constructed a deep second-degree scald model in NIH mice, testing the benefits of exosomes in the scald wound healing. The scratch wound assay, apoptosis assay and MTT assay were conducted to assess the effects of serum-derived exosomes on migration, apoptosis and proliferation of HaCaT cells and fibroblasts. Our results showed that serum-derived exosomes injected subcutaneously entered cells and effectively accelerated wound healing processes in mice. Additionally, serum-derived exosomes optimized functions of cells related to skin injury repair by stimulating fibroblast proliferation, promoting HaCaT cell migration, and suppressing apoptosis of HaCaT cells induced by heat stress. Further study revealed that serum-derived exosomes enhanced phosphorylation of the serine-threonine kinase Akt in scalded skin tissue. These results suggest a potential clinical use of serum-derived exosomes for treating skin scald.

     

The inflammatory response after an epidermal burn depends on the activities of mouse mast cell proteases 4 and 5

A second-degree epidermal scald burn in mice elicits an inflammatory response mediated by natural IgM directed to nonmuscle myosin with complement activation that results in ulceration and scarring. We find that such burn injury is associated with early mast cell (MC) degranulation and is absent in WBB6F1-Kit(W)/Kit(Wv) mice, which lack MCs in a context of other defects due to a mutation of the Kit receptor. To address further an MC role, we used transgenic strains with normal lineage development and a deficiency in a specific secretory granule component. Mouse strains lacking the MC-restricted chymase, mouse MC protease (mMCP)-4, or elastase, mMCP-5, show decreased injury after a second-degree scald burn, whereas mice lacking the MC-restricted tryptases, mMCP-6 and mMCP-7, or MC-specific carboxypeptidase A3 activity are not protected. Histologic sections showed some disruption of the epidermis at the scald site in the protected strains suggesting the possibility of topical reconstitution of full injury. Topical application of recombinant mMCP-5 or human neutrophil elastase to the scalded area increases epidermal injury with subsequent ulceration and scarring, both clinically and morphologically, in mMCP-5-deficient mice. Restoration of injury requires that topical administration of recombinant mMCP-5 occurs within the first hour postburn. Importantly, topical application of human MC chymase restores burn injury to scalded mMCP-4-deficient mice but not to mMCP-5-deficient mice revealing nonredundant actions for these two MC proteases in a model of innate inflammatory injury with remodeling.     

A Randomized and Controlled Multicenter Prospective Study of the Chinese Medicinal Compound Fufang Xuelian Burn Ointment for the Treatment of Superficial and Deep Second-Degree Burn Wounds

The objective of this study was to evaluate the efficacy and safety of a traditional Chinese medicine, Fufang Xuelian Burn Ointment (FXBO), to treat superficial and deep second-degree burn wounds. A four-center, randomized, controlled, and prospective study was conducted. Overall, 240 patients with either superficial or deep second-degree burn wounds were enrolled consecutively in this study. Patients who were randomly assigned to the control group (superficial: 72, deep: 48) underwent common burn wound therapy, whereas those randomized to the treatment group (superficial: 72, deep: 48) received common burn wound therapy plus topical FXBO. The healing rate, healing time, effective rate, and safety data were compared between the two groups. The baseline characteristics were comparable for the two groups. The healing rate was 94.79(±7.50) in the control group and 98.60(±5.69) in the FXBO group after 14 days for patients with superficial second-degree burn wounds (P = 0.000), and 95.17(±9.68) versus 97.44(±9.81) at 28 for deep second-degree burn wounds (P = 0.025). The median healing time in the FXBO group were 9 and 21 days for superficial and deep second-degree burns, respectively, compared to 10.5 and 22.5 days, respectively, in control group (P _superficial = 0.000 and P _deep = 0.009). The results of the effective rate showed that comprehensive efficacy of the FXBO group was improved compared to the control group for either superficial or deep second-degree burns (P _superficial = 0.035 and P _deep = 0.003). There were no reported drug-related adverse events in both groups. Therefore, FXBO was well tolerated and more effective than control group for treating superficial and deep second-degree burn wounds.     

Effect of nano-silver hydrogel coating film on deep partial thickness scald model of rabbit

Objective

Observing the effect of nano-silver hydrogel coating film on deep partial thickness scald model of rabbit.

A dynamic finite element analysis of impulsive loading of the extension-splinted rabbit knee

A dynamic nonlinear finite element model was developed to study juxtarticular stresses in the splinted rabbit knee, an established laboratory model for creating osteoarthrosis due to impulsive loading. Plane strain finite element results were validated by comparison with corresponding experimental data. Parametric effects studied included the input tibial displacement speed, the local bone density distribution, and the modulus of cartilage and subchondral bone. While the computed resultant contact force magnitude was sensitive to a number of model parameters, the stress patterns, when normalized to a given resultant force magnitude, were not. Despite comparable force peaks, the finite element results showed approximately six-fold higher effective strain rate levels for a severely impulsive loading protocol known to induce rapid osteoarthrosis, versus those for a mildly impulsive loading protocol not usually associated with cartilage damage. A propensity for elevated shear in the deep cartilage layer near the contact periphery, observed in nearly all computed stress distributions, is consistent with previous experimental findings of fissuring at that level in the impulsively loaded rabbit knee.     

Temperature regulation in the unrestrained rabbit during exposure to 600 MHz radiofrequency radiation

Six male New Zealand white rabbits were individually exposed to 600 MHz radiofrequency (RF) radiation for 90 min in a waveguide exposure system at an ambient temperature (Ta) of 20 or 30 degrees C. Immediately after exposure, the rabbit was removed from the exposure chamber and its colonic and ear skin temperatures were quickly measured. The whole-body specific absorption rate (SAR) required to increase colonic and ear skin temperature was determined. At a Ta of 20 degrees C the threshold SAR for elevating colonic and ear skin temperature was 0.64 and 0.26 W/kg, respectively. At a Ta of 30 degrees C the threshold SARs were slightly less than at 20 degrees C, with values of 0.26 W/kg for elevating colonic temperature and 0.19 W/kg for elevating ear skin temperature. The relationship between heat load and elevation in deep body temperature shown in this study at 600 MHz is similar to past studies which employed much higher frequencies of RF radiation (2450-2884 MHz). On the other hand, comparison of these data with studies on exercise-induced heat production and thermoregulation in the rabbit suggest that the relationship between heat gain and elevation in body temperature in exercise and from exposure to RF radiation may differ considerably. When combined with other studies, it was shown that the logarithm of the SAR required for a 1.0 degree C elevation in deep body temperature of the rabbit, rat, hamster, and mouse was inversely related to the logarithm of body mass. The results of this study are consistent with the conclusion that body mass strongly influences thermoregulatory sensitivity of the aforementioned laboratory mammals during exposure to RF radiation.     

基于植被指数的典型草原区生物量模型——以内蒙古锡林浩特市为例

利用遥感估测地上生物量是国内外生态学与地理学的研究热点。但基于植被指数的生物量回归模型结果差异较大,究竟哪种植被指数与哪种模型更适合典型草原的生物量反演,是现代草地遥感急需解决的问题之一。该文基于TM影像数据的不同植被指数(VI)差异性,分别选取了RVI(比值植被指数)、NDVI(归一化差异植被指数)、SAVI(土壤调节植被指数)、MASVI(修改型土壤调整植被指数)和RSR(简化比率植被指数)5种植被指数,与同期的内蒙古典型草原区地面实测地上生物量做相关分析,分别建立了5种植被指数与地上生物量的线性及3种非线性(对数、二次多项式、三次多项式)回归模型。研究结果表明:对于中国北方典型草原区而言,地上生物量与5种植被指数(RVI、NDVI、SAVI、MSAVI和RSR)均呈现出显著相关,但地上生物量与后4种植被指数是正相关,与RVI为负相关;利用5种植被指数(RVI、NDVI、SAVI、MSAVI和RSR)监测草地植被生物量的复相关系数均大于0.6,充分说明利用植被指数检测典型草原生物量是一种简单可行的方法;NDVI建立的生物量回归模型,其复相关系数大于其它4类植被指数(RVI、SAVI、MSAVI和RSR),说明NDVI-生物量模型优于植被指数RVI、SAVI、MSAVI和RSR 模型,其模拟地表生物量的效果好;对于TM影像来说,植被生物量的线性模型与3种非线性模型(三次多项式生物量模型、二次多项式生物量模型、对数模型)都表现出较好的模拟效果,都通过了0.01的显著性检验,而且该研究的结果显示出三次多项式生物量回归模型最优,其次是二次多项式生物量模型,再次是线性模型,相对较差的是对数模型。通过NDVI-生物量三次多项式回归模型模拟锡林浩特草原的生物量,可以看出整个研究区的地上生物量基本上是东高西低、东南高西北低的趋势,这与研究区的地形、气候及土地利用等多种因素有关。     

Establishment of a rabbit model of superior vena cava obstruction.

OBJECTIVE: To explore a method of establishing a rabbit model of superior vena cava obstruction (SVCO) by injecting VX2 tumor cell suspension transcutaneously under ultrasound guidance. METHODS: A suspension of VX2 tumor cells was prepared under sterile conditions. Fifteen adult healthy New Zealand White rabbits were enrolled in the experiment. Under ultrasound guidance, about 0.1 ml of the living tumor cell suspension was transcutaneously injected in front of the anterior wall of the right superior vena cava (SVC). The lumen, wall, blood flow of SVCs and adjacent tissues were examined with gray-scale and color Doppler ultrasonography, every 3 days starting from the 9th day after injection. Meanwhile, CT scanning and digital subtraction angiography (DSA) were also performed. The rabbits were dissected immediately after death and tissue samples were collected for pathologic examination. RESULTS: Fourteen out of 15 rabbits developed tumors that were located close to SVCs and/or SVCs cavity, which was shown by ultrasonography. The diameters of the tumors were 80.7 +/- 4.3 mm. These tumors grew close to SVCs area and resulted in compression and infiltration of SVCs. CT scanning and DSA confirmed the establishment of the SVCO model. The achievement rate of the SVCO model was 93.3%. No rabbit died of complications. CONCLUSION: A method of establishing a rabbit SVCO model by injecting VX2 tumor cell suspension under ultrasonographic guidance was established successfully, and it proved to be simple, effective and repeatable. The imaging characteristics of this model are in good accordance with those of SVCO in patients.     

兔食管静脉曲张模型的建立

目的建立新西兰兔的食管静脉曲张模型,为下一步的临床研究提供可靠的小型动物模型。方法采用门静脉左支完全夹闭法造模,并通过外观、超声、胃镜等检查检验手段对造模结果加以评估。结果术后8周存活动物100%可见食管静脉曲张。结论通过门静脉左支夹闭法,基本可以建立兔食管静脉曲张模型。