凝血酶敏感蛋白2在小鼠角膜碱烧伤后修复过程中的表达

目的观察小鼠角膜碱烧伤后修复过程中凝血酶敏感蛋白2(TSP2)的表达情况。方法制作小鼠角膜碱烧伤模型(实验组,35只)。采用HE染色、免疫组织化学和逆转录聚合酶链反应(RT-PCR)等方法,观察对照组(正常小鼠5只)及实验组小鼠碱烧伤后3、6、12、24、48、96、192h(每时相点5只)角膜组织的形态学改变和TSP2、tsp2的表达情况。结果HE染色显示,实验组小鼠伤后24h起角膜内有明显的血管生成。免疫组织化学和RT-PCR检测结果一致显示,TSP2及tsp2在对照组及实验组小鼠角膜组织中均有表达,多见于上皮层的基底层。与对照组的TSP2表达水平(0.48±0.15)比较,实验组小鼠伤后3h TSP2的表达水平即上升(P<0.05),即6h达第1个峰值1.54±0.45,24h降至低谷0.73±0.19,随后又回升,96h时达第2个峰值1.79±0.63,此后下调,至伤后192h降至对照组水平(P>0.05).tsp2的表达趋势与之相似。结论小鼠角膜碱烧伤后TSP2的表达量随时相点的变化呈波动的趋势,这一变化可能属于应激条件下的代偿性增高。     

Evaluation of the effects of resveratrol and bevacizumab on experimental corneal alkali burn

Purpose

To evaluate the effects of resveratrol and bevacizumab on experimental corneal neovascularization.

Method

A corneal alkali burn was performed in 62 eyes of 31 male white Vienna rabbits. Resveratrol (group 1), dimethyl sulfoxide (group 2), bevacizumab (group 3) and 0.9% NaCl (group 4) were administered to both eyes of the rabbits by subconjunctival injection for 7 days. Corneal photos were taken at 15 days after alkali injury. Inflammatory index scores and neovascularization areas were calculated.

Results

In bevacizumab group both inflammatory index scores and the calculation of the corneal neovascularization area was significantly less than the groups.

Conclusion

The subconjunctival administration of bevacizumab inhibits corneal neovascularization effectively in the rabbit corneal alkali burn model. No effect of resveratrol to the corneal neovascularization on experimental model of the corneal alkali burn was seen at the doses of usage.     

Animal study on expression of laminin and fibronectin in cornea during wound healing following alkali burn

Objective:To observe the expression of laminin and fibronectin in alkali-burned corneas in rats.Methods:A total of 18 normal Wistar rats were randomly divided into 6 groups(n=3 in each group).For each rat, one eye was injured by alkali burn,the other one was taken as the normal control.Then all the corneas were surgically removed and the expression of laminin and fibronectin was observed with immunohistochemistry respectively at 7 hours,1 day,3 days, 7 days,14 days and 28 days after alkali burn.Results:Compared with that of the normal controls, the expression of laminin and fibronectin of the burned eyes was dramatically higher at 7 hours, reached peak at 14 days and decreased to the normal level at 28 days after alkali burn.Conclusions:In the process of wound healing after alkali burn, the expression of laminin and fibronectin increases dramatically, which suggests that laminin and fibronectin may participate in the process of corneal wound healing.     

羊膜移植联合碱性成纤维细胞生长因子滴眼液治疗兔角膜碱烧伤

目的 观察羊膜移植与碱性成纤维细胞生长因子(bFGF)滴眼液联合应用对兔角膜碱烧伤的治疗效果。方法 将60只新西兰白兔随机分为4组,分别为羊膜移植联合bFGF滴眼液点眼组(A组),羊膜移植组(B组),bFGF滴眼液点眼组(C组)及对照组(D组)。用1 mol/L NaOH烧伤兔右眼,术后2 ～28 d用裂隙灯显微镜观察角膜透明度,新生血管生长,角膜上皮修复及羊膜植片的变化。结果 所有烧伤角膜都能完全愈合,但在抑制炎症反应、抗新生血管的生长及角膜上皮修复等方面,羊膜移植联合bFGF滴眼液点眼组明显优于对照组,也好于其他两实验组,差异有统计学意义(P＜0.05)。结论 羊膜移植联合bFGF滴眼液点眼对治疗角膜碱烧伤有良好效果。     

Prediction of burn healing time using artificial neural networks and reflectance spectrometer

BACKGROUND: Burn depth assessment is important as early excision and grafting is the treatment of choice for deep dermal burn. Inaccurate assessment causes prolonged hospital stay, increased medical expenses and morbidity. Based on reflected burn spectra, we have developed an artificial neural network to predict the burn healing time. PURPOSE: Our study is to develop a non-invasive objective method to predict burn-healing time. METHODS AND MATERIALS: Burns less than 20% TBSA was included. Burn spectra taken on the third postburn day using reflectance spectrometer were analyzed by an artificial neural network system. RESULTS: Forty-one spectra were collected. With the newly developed method, the predictive accuracy of burns healed in less than 14 days was 96%, and that in more than 14 days was 75%. CONCLUSIONS: Using reflectance spectrometer, we have developed an artificial neural network to determine the burn healing time with 86% overall predictive accuracy.     

Extracorporeal shock waves improve angiogenesis after full thickness burn

Objective

Extensive wounds of burn patients remain a challenge due to wound infection and subsequent septicemia. We wondered whether extracorporeal shock wave application (ESWA) accelerates the healing process. The aim of the study was to analyze microcirculation, angiogenesis and leukocyte endothelium interaction after burns by using ESWA with two types of low intensity.

Methods

Full-thickness burns were inflicted to the ears of hairless mice (n = 51; area: 1.3 mm²). The mice were randomized into five groups: (A) low-energy shock waves after burn injury (0.04 mJ/mm²); (B) very low-energy shock waves after burn injury (0.015 mJ/mm²); (C) mice received burns but no ESWA (control group); (D) mice without burn were exposed to low-energy shock waves; (E) mice without burns and with no shock wave application. Intravital fluorescent microscopy was used to assess microcirculatory parameters, angiogenesis and leukocyte behavior. ESWA was performed on day 1, 3 and 7 (500 shoots, 1 Hz). Values were obtained straight after and on days 1, 3, 7 and 12 post burn.

Results

Group A showed accelerated angiogenesis (non-perfused area at day 12: 5.3% vs. 9.1% (group B) and 12.6% (group C), p = 0.005). Both shock wave groups showed improved blood flow after burn compared to group C. Shock waves significantly increased the number of rolling leukocytes compared to the non-ESWA-treated animals (group D: 210.8% vs. group E: 83.3%, p = 0.017 on day 7 and 172.3 vs. 90.9%, p = 0.01 on day 12).

Conclusion

Shock waves have a positive effect on several parameters of wound healing after burns, especially with regard to angiogenesis and leukocyte behaviour. In both ESWA groups, angiogenesis and blood flow outmatched the control group. Within the ESWA groups the higher intensity (0.04 mJ/mm²) showed better results than the lower intensity group. Moreover, shock waves increased the number of rolling and sticking leukocytes as a part of an improved metabolism.     

组织工程角膜上皮移植抑制角膜碱烧伤新生血管形成的临床观察

目的：观察组织工程角膜上皮移植对角膜碱烧伤新生血管的抑制作用.方法：我院2005-2010年期间收治严重角膜碱烧伤（角膜缘干细胞缺陷）17例24眼,其中组织工程角膜上皮移植9例11眼,羊膜移植8例13眼.所有患者在手术前及手术后均行裂隙灯检查,观察角膜上皮、组织浸润、新生血管情况,对两组患者角膜新生血管情况进行评分和比较.结果：术后两组角膜新生血管评分均较手术前明显减少（P〈0.05）.在术后第21天,组织工程角膜上皮移植和羊膜移植组角膜新生血管评分分别为（1.410±0.765）分和（2.500±0.961）分,术后第60天分别为（1.770±0.832）分和（2.820±0.947）分.在术后两个评价时间点,组织工程角膜上皮移植组均较羊膜移植组角膜新生血管显著减少,两组间差异有显著性（P〈0.05）.组织工程角膜上皮移植组和羊膜移植组术后第60天新生血管评分均较术后第21天稍高,但差异均无显著性（P〉0.05）,表明两组角膜新生血管在移植3周后基本保持稳定.结论：组织工程角膜上皮移植对严重的角膜碱烧伤新生血管的抑制作用明显好于羊膜移植.     

羊膜移植治疗眼烧伤疗效的观察

目的评价羊膜移植治疗眼部烧伤的疗效。方法2000年10月～2002年5月，对20例患者(28眼)采用羊膜移植治疗眼烧伤，其中碱烧伤6例(10眼)，酸烧伤8例(10眼)，热烧伤6例(8眼)。年龄8～45岁，平均28．6岁．烧伤部位包括角膜、结膜。受伤至手术时间1～21天，平均10天。结果28眼术后3～7天眼部炎症控制，角、结膜均未见继续溶解，无穿孔，无虹膜萎缩，视力有不同程度提高；16眼角膜恢复透明，4眼角膜白斑，8眼全角膜浑浊。全部患者均保存了眼球，眼表稳定，无免疫排斥反应及继发感染发生。结论羊膜移植可以减轻炎性反应，减少新生血管的生成，抑制纤维组织增生，对重建眼表功能及保存眼球有较高的价值，可有效地用于眼部烧伤的治疗，烧伤后手术愈早效果愈好。     

(-)-Epigallocatechin-3-gallate,reduces corneal damage secondary from experimental grade II alkali burns in mice

Background

Since recent reports have shown that (-)-Epigallocatechin-3-gallate (EGCG) could be used for treating proliferative and inflammatory disorders, we explored its use for the management of corneal chemical burns.

The establishment of a Pseudomonas aeruginosa-infected burn-wound sepsis model and the effect of imipenem treatment

INTRODUCTION: We present a standardized Pseudomonas aeruginosa (PA) infected burn-wound model in mice for evaluating new antimicrobials and therapy strategies for PA infections and demonstrate the effect of the antibiotic imipenem in this model. METHODS: A 6%-8% total body surface area, full-thickness, scald-burn wound was induced in anesthetized mice. Two study groups (PA-infected burn) were compared with 1 treatment group (systemic imipenem) and 3 control groups (noninfected burn, infected nonburned, and burn with distant infection). Seven-day mortality, quantitative culture from eschars and from spleens, weight loss, and time to healing were compared. RESULTS: The 25%-100% mortality rate in the nontreated PA-infected burn group was directly related to the infecting inoculum. Imipenem treatment reduced the mortality rate to 0-17%. No control animal died. Systemic bacterial dissemination at 48 hours was significantly higher in the study group. Morbidity paralleled survival results. Wound healing was quicker in the imipenem-treated group and control groups compared with the infected nontreated group. CONCLUSIONS: The mice model is a useful tool for evaluating new antibacterial agents and strategies for treating PA-infected burn injuries. Imipenem was found to be efficacious in the treatment of severe PA sepsis.     

Deficiency of CX3CR1 delays burn wound healing and is associated with reduced myeloid cell recruitment and decreased sub-dermal angiogenesis

The development of a good blood supply is a key step in burn wound healing and appears to be regulated in part by myeloid cells. CX3CR1 positive cells have recently been identified as myeloid cells with a potential role in angiogenesis. The role of functional CX3CR1 system in burn wound healing is not previously investigated. A 2% contact burn was induced in CX3CR1(+/gfp) and CX3CR1(gfp/gfp) mice. These transgenic mice facilitate the tracking of CX3CR1 cells (CX3CR1(+/gfp)) and allow evaluation of the consequence of CX3CR1 functional knockout (CX3CR1(gfp/gfp)) on burn wound healing. The progression of wound healing was monitored before tissue was harvested and analyzed at day 6 and day 12 for migration of CX3CR1 cells into burn wound. Deficiency of a functional CX3CR1 system resulted in decreased recruitment of CX3CR1 positive cells into the burn wound associated with decreased myeloid cell recruitment (p<0.001) and reduced maintenance of new vessels (p<0.001). Burn wound healing was prolonged (p<0.05). Our study is the first to establish a role for CX3CR1 in burn wound healing which is associated with sub-dermal angiogenesis. This chemokine receptor pathway may be attractive for therapeutic manipulation as it could increase sub dermal angiogenesis and thereby improve time to healing.     

Transplantation of reconstructed corneal layer composed of corneal epithelium and fibroblasts on a lyophilized amniotic membrane to severely alkali-burned cornea

The purpose of this article was to evaluate the graft efficacy of reconstructed corneal layer, composed of autologous corneal epithelium and fibroblasts on a lyophilized amniotic membrane (LAM), in a severely alkali-burned corneal model. After biopsy specimens were obtained from the left eyes of 24 rabbits, the corneal epithelial cells and fibroblasts were expanded in vitro and the corneal layer was reconstructed on LAM. Thirty-six eyes of rabbits underwent alkali burn (1 N NaOH, 30 s) to create a limbal deficiency and a deeply damaged corneal stroma. Four weeks later, group 1 underwent a graft of the reconstructed corneal layer composed of autologous corneal epithelium and fibroblasts on LAM. Group 2 was transplanted with a graft of the reconstructed autologous corneal epithelium, and group 3 served as a control without surgery. Wound healing and stabilization of the ocular surfaces occurred much faster in group 1 than in groups 2 and 3. The eyes in group 3 revealed typical limbal deficiencies with conjuctivalization and persistent corneal epithelial defects. However, the corneas in group 1 developed only mild peripheral neovascularization. Immunohistochemical staining in group 1 demonstrated that p63, cytokeratin 3, E-cadherin, transforming growth factor (TGF)-beta1, and collagen IV were expressed strongly in the corneal epithelium and basement membrane. On the basis of these results, transplantation of the reconstructed corneal layer, composed of autologous corneal epithelium and fibroblasts on LAM, partially accelerated the recovery of the alkali-injured rabbit ocular surface, and might be useful therapeutically for the treatment of patients with severely damaged cornea.     

化学烧伤患者眼睑全层缺损的早期修复

目的探讨化学烧伤导致患眼睑全层缺损后早期修复的时机和方法。方法化学烧伤致眼睑全层缺损患18例(19只眼)。4周内进行游离鼻中膈黏膜软骨瓣 肌皮瓣植皮或皮瓣转移修复，其中4例眼睑再造与角膜移植同时完成。结果再造眼睑及移植角膜全部成活，减少了暴露性角膜炎、角膜溃疡、眼球穿孔等严重并发症的发生。结论化学烧伤致全层眼睑缺损应早期修复，包括为保护视力、减轻炎症进行的眼睑及时再造，和角膜有穿孔危险情况下与角膜移植同期进行的眼睑再造；鼻中膈黏膜软骨是再造眼睑较为理想的材料。     

严重烧伤后小鼠腹腔巨噬细胞（Mφ）CD14表达的变化

目的 探讨烧伤后早期腹腔Mφ CD14分子的动态变化。方法 采用小鼠20％TB-SAⅢ度烧伤模型，分离和培养小鼠腹腔Mφ，用免疫组织化学、RT—PCR和ELISA方法，观察了烧伤复苏组和延迟复苏组伤后24h内不同时间腹腔Mφ表达CD14和CD14 mRNA、分泌肿瘤坏死因子(TNF)和白介素-6(IL-6)的变化。结果 烧伤复苏组和延迟复苏组在伤后1h腹腔Mφ表达CD14和分泌TNFα、IL-6明显增加，这种改变在伤后24h内持续。结论烧伤能增加Mφ CD14 mRNA的表达，从而使Mφ易于被很低浓度内毒素(LPS)激活，Mφ的致敏和激活使其在伤后过度炎症反应的发生发展中起重要作用。     

Effects of dietary arginine supplementation on antibody production and antioxidant enzyme activity in burned mice

This study investigated the effect of arginine (Arg) supplementation on specific antibody production and antioxidant enzyme activities in burned mice vaccinated with detoxified Pseudomonas exotoxin A linked with the outer membrane proteins I and F, named PEIF. Also, the survival rate of burned mice complicated with Pseudomonas aeruginosa was evaluated. Experiment 1: Thirty BALB/c mice were assigned to two groups. One group was fed a control diet with casein as the protein source, while the other group was supplemented with 2% Arg in addition to casein. The two groups were isonitrogenous. The mice were immunized twice with PEIF, and the production of specific antibodies against PEIF was measured every week. After 8 weeks, all mice received a 30% body surface area burn injury. Mice were sacrificed 24h after the burn. The antioxidant enzyme activities and lipid peroxides in the tissues as well as the specific antibody production were analyzed. Experiment 2: Twenty-eight mice were divided into two groups and vaccinated as described in experiment 1. After the burn the mice were infected with P. aeruginosa, and the survival rate was observed for 8 days. The results demonstrated that antioxidant enzyme activities and lipid peroxides in tissues were significantly lower in the Arg group than in the control group after the burn. The production of specific antibodies against P. aeruginosa significantly increased in the Arg group at 4 and 7 weeks after immunization, and 24h after the burn. The survival rates of vaccinated burned mice after bacterial infection did not significantly differ between the two groups. These results suggest that vaccinating mice with Arg supplementation may enhance humoral immunity and attenuate the oxidative stress induced by burn injury. However, Arg supplementation did not improve survival in vaccinated mice complicated with P. aeruginosa infection.     

外源性一氧化碳释放分子2对严重烧伤小鼠肝脏炎性反应的抑制作用

目的 观察外源性一氧化碳释放分子2（CORM-2）对严重烧伤小鼠肝脏炎性反应的抑制作用，并探讨其机制。方法 将C57BL／6小鼠随机分成假伤组（模拟烧伤）、假伤＋CORM-2组、烧伤组、烧伤＋CORM-2组及烧伤＋二甲亚砜（DMSO）组，每组9只。假伤＋CORM-2组除伤后使用CORM-2以外，其他处理同假伤组。烧伤＋CORM-2组及烧伤＋DMSO组除伤后分别使用CORM-2、DMSO外，其余处理同烧伤组。于伤后24h检测小鼠血清丙氨酸转氨酶（ALT）及天冬氨酸转氨酶（AST）的水平，肝组织髓过氧化物酶（MPO）及核因子KB（NF-kB）活性，胞间黏附分子1（ICAM-1）和血管细胞黏附分子1（VCAM-1）蛋白的表达；检测各组小鼠肝窦内皮细胞（HSEC）经各自血清刺激后对中性粒细胞（PMN）的黏附作用。结果 与假伤组比较，烧伤组小鼠血清ALT、AST的水平[（398±34）、（122±22）U／L]及肝组织MPO活性、肝组织ICAM-1和VCAM-1蛋白表达水平均明显升高（P〈0．05或P〈0．01）。与烧伤组比较，烧伤＋CORM-2组上述情况明显改善，且NF-kB活性下降。与假伤组比较，烧伤组小鼠HSEC对PMN的黏附作用增强；烧伤＋CORM-2组该作用明显弱于烧伤组（P〈0．05）。结论 外源性CORM-2能明显抑制肝组织NF-kB活性，减少ICAM-l、VCAM-l蛋白的表达水平，减轻严重烧伤后组织中白细胞滞留，改善肝功能，可有效减轻肝脏炎性反应。     

Improving burn depth assessment for pediatric scalds by AI based on semantic segmentation of polarized light photography images

This paper illustrates the efficacy of an artificial intelligence (AI) (a convolutional neural network, based on the U-Net), for the burn-depth assessment using semantic segmentation of polarized high-performance light camera images of burn wounds. The proposed method is evaluated for paediatric scald injuries to differentiate four burn wound depths: superficial partial-thickness (healing in 0–7 days), superficial to intermediate partial-thickness (healing in 8–13 days), intermediate to deep partial-thickness (healing in 14–20 days), deep partial-thickness (healing after 21 days) and full-thickness burns, based on observed healing time.In total 100 burn images were acquired. Seventeen images contained all 4 burn depths and were used to train the network. Leave-one-out cross-validation reports were generated and an accuracy and dice coefficient average of almost 97% was then obtained. After that, the remaining 83 burn-wound images were evaluated using the different network during the cross-validation, achieving an accuracy and dice coefficient, both on average 92%.This technique offers an interesting new automated alternative for clinical decision support to assess and localize burn-depths in 2D digital images. Further training and improvement of the underlying algorithm by e.g., more images, seems feasible and thus promising for the future.     

Real-time burn depth assessment using artificial networks: a large-scale,multicentre study

IntroductionEarly judgment of the depth of burns is very important for the accurate formulation of treatment plans. In medical imaging the application of Artificial Intelligence has the potential for serving as a very experienced assistant to improve early clinical diagnosis. Due to lack of large volume of a particular feature, there has been almost no progress in burn field.Methods484 early wound images are collected on patients who discharged home after a burn injury in 48 h, from five different levels of hospitals in Hunan Province China. According to actual healing time, all images are manually annotated by five professional burn surgeons and divided into three sets which are shallow(0–10 days), moderate(11–20 days) and deep(more than 21 days or skin graft healing). These ROIs were further divided into 5637 patches sizes 224 × 224 pixels, of which 1733 shallow, 1804 moderate, and 2100 deep. We used transfer learning suing a Pre-trained ResNet50 model and the ratio of all images is 7:1.5:1.5 for training:validation:test.ResultsA novel artificial burn depth recognition model based on convolutional neural network was established and the diagnostic accuracy of the three types of burns is about 80%.DiscussionThe actual healing time can be used to deduce the depth of burn involvement. The artificial burn depth recognition model can accurately infer healing time and burn depth of the patient, which is expected to be used for auxiliary diagnosis improvement.     

Effects of arginine supplementation on antioxidant enzyme activity and macrophage response in burned mice

This study investigated the effect of arginine (Arg) supplementation on antioxidant enzyme activities and macrophage response in burned mice. Experiment 1: 60 male BALB/c mice were assigned to two groups. One group was fed a control diet with casein as the protein source, the other group was supplemented with 2% Arg in addition to casein. The two groups were isonitrogenous. After 4 weeks, all mice received a 30% body surface area burn injury. The antioxidant enzyme activities and lipid peroxides in the tissues were analyzed. Experiment 2: 20 mice were divided into two groups and burn injury was induced after feeding for 4 weeks as described in experiment 1. Twenty-four hours after the burn, tumor necrosis factor-alpha (TNF-alpha) secreted by cultured peritoneal macrophages was measured. The results show that antioxidant enzyme activities and lipid peroxides in tissues tended to be lower in the Arg group than in the control group after the burn. Production of TNF-alpha by peritoneal macrophages after stimulation with lipopolysacchride (LPS) was significantly elevated in the Arg group, whereas no response was observed in the control group. These results suggest that dietary Arg supplementation attenuates the oxidative stress induced by burn injury, and a better macrophage response was observed when Arg was administered.     

不同材料人工真皮支架修复猪Ⅲ度烧伤创面比较

目的 比较胶原壳聚糖真皮支架、胶原磺化羧甲基壳聚糖真皮支架及脱细胞基质真皮支架移植于Ⅲ度烧伤创面后,真皮支架的血管化及支架上表皮移植修复创面情况.方法 将3种不同真皮支架各移植于6头猪(共18头猪)Ⅲ度烧伤清创后创面,在植入后1、2、3周对真皮支架血管化、创面、支架上表皮移植愈合和修复情况进行观察,同时用免疫组织化学方法,对CD34阳性信号(新生血管数目)进行检测.以无支架植入的Ⅲ度烧伤清创后创面为对照.结果 胶原磺化羧甲基壳聚糖真皮支架植入后2周支架血管化已基本完成,而胶原壳聚糖和脱细胞基质真皮支架至少需要3周.3种不同材料支架垂直于创面的新生微血管均比无支架对照创面多;不同材料支架组与对照组2周创面比1周创面、3周创面比2周创面CD34的表达均明显增多,胶原磺化羧甲基壳聚糖真皮支架组植入后1、2、3周CD34阳性信号均明显高于相对应的其他3组;胶原磺化羧甲基壳聚糖真皮支架植入后1周,创面植表皮,移植表皮存活良好,而胶原壳聚糖和脱细胞基质真皮支架植入需要2周,其表面移植的表皮细胞才能成活.结论 3种材料的支架均可修复Ⅲ度烧伤创面,而以胶原磺化羧甲基壳聚糖真皮支架的血管化程度最好.