In vivo imaging of human burn injuries with polarization-sensitive optical coherence tomography

The accurate determination of burn depth is critical in the clinical management of burn wounds. Polarization-sensitive optical coherence tomography (PS-OCT) has been proposed as a potentially non-invasive method for determining burn depth by measuring thermally induced changes in the structure and birefringence of skin, and has been investigated in pre-clinical burn studies with animal models and ex vivo human skin. In this study, we applied PS-OCT to the in-vivo imaging of two pediatric burn patients. Deep and superficial burned skins along with contralateral controls were imaged in 3D. The imaging size was 8 mm × 6 mm × 2 mm in width, length, and depth in the air respectively, and the imaging time was approximately 6 s per volume. Superficially burned skins exhibited the same layered structure as the contralateral controls, but more visible vasculature and reduced birefringence compared to the contralateral controls. In contrast, a deeply burned skin showed loss of the layered structure, almost absent vasculature, and smaller birefringence compared to superficial burns. This study suggested the vasculature and birefringence as parameters for characterizing burn wounds.     

An approach of in vivo measurement for ultrasonic myocardial tissue characterization

The purpose of this study is to characterize regional myocardial alternations of reflected ultrasound throughout a cardiac cycle in normal and ischemic myocardium. Integrated ultrasonic backscatter (2-5 MHz) gated R wave of ECG was measured at the base, middle and apex in 4 dogs, and the apex before and after ischemia in other 4 dogs. Quantitative ultrasonic backscatter (IB) was reflected to a steel reflector. At the apex and middle, where a cyclic pattern of IB was discernible, maximum values were recorded near end diastole and minimum near end systole. The amplitude of the variation of IB throughout a cardiac cycle for each region increase progressively from base to middle to apex. Time-averaged IB over a cardiac cycle (averaged IB) was similar for each area of the heart (base = -50.6 +/- 0.5 dB (mean +/- SE), middle -49.4 +/- 0.5 dB, apex -49.7 +/- 0.6 dB. p = NS for comparison of any two regions). After occluding left anterior descending coronary artery for 30 minutes, the variation of IB was markedly blunted and averaged IB increased significantly (-47.5 +/- 0.5 dB. p less than 0.01 compared with preocclusion (-50.8 +/- 0.5 dB]. These results suggested that IB and averaged IB may permit assessment of intrinsic geometrical changes throughout a cardiac cycle (contractile properties) and histological changes respectively.     

三维扫描技术精确控制大鼠烫伤面积动物模型的建立

目的 建立一种可精确控制烫伤面积的大鼠模型.方法 40只大鼠被随机分为5组,每组8只,根据接触94℃热水时间不同分别为6 s组、8 s组、10 s组、12 s组、14 s组,以热水接触作为致伤原因,持续时间控制烫伤深度.比较各组创面烫伤深度和愈合时间,并经病理证实.另取9只大鼠作为3D扫描组,接触94℃热水12 s,烫伤24 h后应用3D流动式双目三维扫描技术,扫描计算大鼠体表面积及烫伤部位占体表总面积的百分比,并与实体解剖测量结果进行比较.结果 12 s组烫伤创面深度可达（34.2±2.9）mm,且无毛囊及汗腺附件存在.创面愈合时间为（24.4±2.2）d,病理证实烫伤深度为深Ⅱ度～Ⅲ度;流动式双目三维扫描技术确认的烫伤面积与实体解剖测量所得结果差异无统计学意义（P〉0.05）.结论 以热水接触为致伤原因,配合三维扫描技术测量烫伤面积精确可信,该模型可以控制烫伤深度、精确烫伤面积,是研究烧（创）伤修复机制及评价创面用药的良好动物模型.     

Feasibility study of using high-frequency ultrasonic Nakagami imaging for characterizing the cataract lens in vitro

A cataract is a clouding of the crystalline lens that reduces the amount of incoming light and impairs visual perception. Phacoemulsification is the most common surgical method for treating advanced cataracts, and determining the optimal phacoemulsification energy is dependent on measuring the hardness of the lens. This study explored the feasibility of using an ultrasonic parametric image based on the Nakagami distribution to quantify the lens hardness. Young's modulus was measured in porcine lenses in which cataracts had been artificially induced. High-frequency ultrasound at 35 MHz was used to obtain the B-mode and Nakagami images of the cataract lenses. The averaged integrated backscatter and Nakagami parameters were also estimated in the region of interest. The experimental results show that the conventional B-scan and integrated backscatter are inadequate for quantifying the lens hardness, whereas Nakagami imaging allows different degrees of lens hardening to be distinguished both globally and locally based on the concentration of fiber coemption therein.     

微型皮片移植方法在大面积深度烧伤中的应用

临床医师使用外科方法清除失去活力的烧伤坏死组织,并迅速封闭广泛开放的创面,已成为现代大面积深度烧伤救治的常用方法,也是预防烧伤严重感染的根本措施。但在治疗时,突出的矛盾是患者自体皮源不足,希望用少量甚至极少量的自体皮肤移植修复大面积深度创面成为临床工作者不断探索的命题。在皮肤移植的发展史上,经历了点状植皮、邮票植皮、网状植皮、筛状植皮、自体微粒皮或皮浆和异体皮混合移植、Meek微型皮片移植乃至自体细胞培养复合移植等多种方法,这些方法在实际使用中各有其优缺点和局限性。其中,自体微粒皮移植、自体皮浆移植及Meek植皮术是当前大面积深度烧伤患者常用的微型皮片移植方法,基本上解决了大面积深度烧伤患者供皮面积小而植皮面积大的矛盾。自体微粒皮移植需要异体皮肤或异种皮肤作为载体覆盖才能完成,包括大张异体皮覆盖自体微粒皮移植和大张异种皮覆盖自体微粒皮移植。自体皮浆移植尽管操作简单方便,但对创面条件要求更高。自体微粒皮移植及自体皮浆移植这两种植皮技术作为特大面积深度烧伤患者的传统创面修复方法,尽管受诸多限制,目前应用仍较广泛。Meek植皮技术,以其独特的皮片扩张技术和机械化操作大大改变了传统的徒手操作方式,目前已成为修复大面积深度烧伤创面较为理想的方法。     

Experimental candidiasis after thermal injury.

The ability of Candida albicans to infect thermally injured mice was studied. Female mice were either left unburned or given a 20% total body surface area 2-s or 7-s scald burn. The wound or skin surface was then inoculated with a human burn wound isolate of C. albicans. At 4 h postburn, approximately 10(2) to 10(3) CFU/g of tissue could be recovered from the skin of burned and unburned animals. Unburned mice cleared the organisms from the skin by 72 h, whereas in 7-s-burned animals, the candida increased in numbers to approximately 10(7) CFU/g of tissue. The ability of the organisms to invade systemically after wound surface inoculation was examined in mice given either a 2-s or a 7-s scald burn. Each injury was histologically confirmed as a full-thickness (third degree) burn, with slightly deeper tissue damage observed with the 7-s burn. At each time period examined (1, 4, 7, and 10 days), there were significantly fewer organisms in the wounds of mice given the 2-s injury than in wounds of mice burned for 7 s (P less than 0.05). In 3 of 33 mice given a 7-s injury, organisms were recovered from the kidneys at the time of sacrifice, whereas no evidence of invasion into the kidneys was noted in mice given a 2-s thermal injury. This study demonstrated that thermal injury enhances the ability of C. albicans to infect mice and that the depth of burn appears to be an important factor in determining whether the organisms can invade the burn wound to cause systemic infection. This animal model should be valuable in elucidating the virulence factors of C. albicans that play a role in the pathogenesis of candidiasis after thermal injury.     

-80℃冻干猪二道皮用于Ⅱ度烧伤创面换药方法的改进

目的应用自制-80％冻干猪二道皮（类似仿猪真皮）覆盖Ⅱ度烧伤创面，改进传统的换药方法并评价其效果。方法取小型健康白色家猪的新鲜皮，经常规清洁剃毛，以电动取皮机去脂，制成去表皮刃厚猪二道皮，经处理后放入-80％冰箱冻存备用。临床分为两组：A组为观察组共42例，以猪二道皮覆盖创面，B组为对照组共76例，以10％磺胺嘧啶银霜油纱布传统方法交敷创面。结果浅Ⅱ度创面愈合时间，A组平均（10．67±2．08）天，B组（13．1±1．73）天（P〈0．01）；深Ⅱ度创面愈合时间，A组平均（20．8±2．03）天，B组（23．20±2．60）天（P〈0．01）。结论与传统的换药方法相比，以猪二道皮覆盖烧伤创面，能促进上皮细胞生长，减轻疼痛，缩短愈合时间，减少疤痕和畸形的产生。     

脱细胞异体真皮与PELNAC联合烧伤瘢痕表皮移植治疗烧伤瘢痕的对比研究

目的 探讨脱细胞异体真皮联合自体深二度烧伤瘢痕表皮移植与皮耐克联合深二度烧伤瘢痕表皮移植在烧伤瘢痕治疗中的疗效比较。方法 选取2015年1月~2017年12月到我院治疗的烧伤瘢痕患者60例,进行随机分组,采用脱细胞异体真皮联合自体深二度烧伤瘢痕表皮移植治疗烧伤瘢痕患者（A组）30例,采用皮耐克联合深二度烧伤瘢痕表皮移植治疗烧伤瘢痕患者（B组）30例。分别比较两组的创面愈合时间,于创面愈合后6个月后进行随访并采用温哥华瘢痕量表（VSS）评价瘢痕情况以及参照ADL分级标准评定关节功能。结果 A组创面愈合时间为（12.07±4.30）d,短于B组的（22.00±3.85）d,差异有统计学意义（P＜0.05）;A组VSS评分为（4.10±3.27）分,B组为（4.40±3.80）分,两组差异无统计学意义（P＞0.05）。A组ADL评分:优5例,良12例,中10例,差3例;B组ADL评分:优4例,良11例,中10例,差5例;组间比较,差异无统计学意义（P＞0.05）。结论 脱细胞异体真皮联合自体深二度烧伤瘢痕表皮移植治疗烧伤瘢痕疗效,与皮耐克联合深二度烧伤瘢痕表皮移植治疗烧伤瘢痕疗效无明显差异,但脱细胞异体真皮联合自体深二度烧伤瘢痕表皮移植较皮耐克联合深二度烧伤瘢痕表皮移植创面愈合时间短,在临床有一定优势。     

The effect of logarithmic compression on estimation of the Nakagami parameter for ultrasonic tissue characterization: a simulation study

Previous studies have demonstrated that the Nakagami parameter estimated using the envelopes of backscattered ultrasound is useful in detecting variations in the concentration of scatterers in tissues. The signal processing in those studies was linear, whereas nonlinear logarithmic compression is routinely employed in existing ultrasonic scanners. We therefore explored the effect of the logarithmic compression on the estimation of the Nakagami parameter in this study. Computer simulations were used to produce backscattered signals of various scatterer concentrations for the estimation of the Nakagami parameters before and after applying the logarithmic compression on the backscattered envelopes. The simulated results showed that the logarithmic compression would move the statistics of the backscattered envelopes towards post-Rayleigh distributions for most scatterer concentrations. Moreover, the Nakagami parameter calculated using compressed backscattered envelopes is more sensitive than that calculated using uncompressed envelopes in differentiating variations in the scatterer concentration, making the former better at quantifying the scatterer concentration in biological tissues.     

山莨菪碱对烫伤大鼠血管通透性变化的影响

山莨菪碱对烫伤大鼠血管通透性变化的影响谢建军１林国成２姚秀娟１贾敏１杨瑟飞３赵德化１烧伤后血管通透性的改变是引起组织水肿和内环境紊乱的病理学基础。如何阻止或逆转血管通透性的改变，减轻水肿形成，已成为烧伤的重要研究内容之一。已发现山莨菪碱能减轻大鼠烧伤...     

严重烧伤创面深度对休克期晶、胶体补液量影响的临床分析

目的探讨严重烧伤不同的创面深度对烧伤患者休克期晶、胶体补液量的影响。方法收集2002年10月至2009年1月间青岛市立医院收治的63例烧伤面积大于50%、年龄大于14岁、伤后到入院时间少于6h并且平稳度过休克期的烧伤患者。观察其浅Ⅱ度、深Ⅱ度、Ⅲ度面积(X1、X2、X3)及伤后第1天、第2天的晶体、胶体量。通过数值转换计算出创面因素Y(K×烧伤面积)=(晶体+胶体)/体重,使用SPSS17.0统计软件对浅Ⅱ度、深Ⅱ度、Ⅲ度面积及创面因素进行多元线性回归分析,求得回归方程。经方程转换得到浅Ⅱ度、深Ⅱ度、Ⅲ度面积和体重与补液量的关系。结果自变量浅Ⅱ度、深Ⅱ度、Ⅲ度烧伤面积与因变量创面因素Y呈线性相关,回归方程:第1天为Y=1.370×X1+1.682×X2+1.851×X3;第2天为Y=0.810×X1+0.817×X2+1.184×X3。且总的回归方程及各个自变量均有统计意义,P0.001。结论大面积烧伤患者早期补液不仅与烧伤面积有关,而且与烧伤深度关系密切。传统的烧伤补液公式应增加烧伤深度因素参数,第1天晶体与胶体补液量(mL)为(1.4×浅Ⅱ度面积+1.7×深Ⅱ度面积+1.9×Ⅲ度烧伤面积)×体重;第2天为(0.8×浅Ⅱ度面积+0.8×深Ⅱ度面积+1.2×Ⅲ度烧伤面积)×体重。     

RGTA OTR4120, a heparan sulfate mimetic, is a possible long-term active agent to heal burned skin

Burn-related skin fibrosis leads to loss of tissue function and hypertrophic scar formation with damaging consequences for the patient. There is therefore a great need for an efficient agent to treat burned skin. We report that ReGeneraTing Agent (RGTA) reduces burn-induced skin alteration. The tissue-regenerating effect of RGTA OTR4120 was evaluated after 1-6 days and after 10 months in a rat skin burn model. This effect was also examined in vitro using fibroblasts isolated from control and 6-day-old burned skins. We measured production of dermal collagen I, III, and V and activities of metalloproteinases 2 and 9 (MMP-2 and MMP-9). Ratio of collagen III over collagen I production increased 6 days after the burn, because of a decrease in collagen I production. After 10 months, ratio of collagen III over collagen I in burn sites was still increased compared with control skin, because of an increase in collagen III production. Both abnormalities were corrected by OTR4120. OTR4120 increased pro- and active MMP-2 and MMP-9, compared with healthy and burned controls and therefore accelerated remodeling. Similar data were obtained with cultured fibroblasts from healthy and burned skins. OTR4120 enhanced healing in short- and long-term after burns, reducing the formation of fibrotic tissue, and then represents a potential agent to improve burned skin healing.     

选择性去细胞猪皮在深Ⅱ度烧伤创面中的应用

目的将选择性去细胞猪皮用于深Ⅱ度烧伤创面早期包扎,观察其创面保护和促愈效果。方法 41例烧伤患者,男性29例,女性12例,年龄18～53岁,平均（31.4±9.7）岁,烧伤面积5%～39%。伤后2～4d,2%创面清创后以选择性去细胞猪皮覆盖,其余创面常规换药,以同体同侧或对侧创面作为对照,隔日换药,观察创面愈合情况,计算伤后2周创面愈合率,记录创面愈合时间。结果选择性去细胞猪皮与创面基底贴敷良好,创周无红肿等炎症反应表现,14～21d逐渐干燥、脱落,创面愈合。伤后2周创面愈合率（82.34±20.13）%,对照组为（76.21±22.52）%。创面平均愈合时间（17.8±4.3）d,对照组为（21.2±5.6）d。两者相比差异均有统计学意义。结论选择性去细胞猪皮对于清创后的深Ⅱ度烧伤创面有较好的保护和促愈作用,效果优于常规换药方法。     

血必净注射液改善重度烧伤休克期血液流变学的临床研究

目的观察重度烧伤患者休克期的血液流变学改变及应用血必净注射液中西医结合治疗的疗效。方法20例重度烧伤患者，伤后随机分为血必净治疗组（n=10）和对照组（n=10）。血必净治疗组接受常规液体复苏＋血必净注射液50ml静滴，2次／d。对照组接受常规液体复苏。结果治疗组用药后全血低切黏度为（9．55±1．74）mPa·S，全血高切黏度为（4．05±0．81）mPa·S，血浆黏度为（1．79±0．07）mPa·s，红细胞聚集指数为2．09±0．22、红细胞变形指数为0．47±0．05。对照组全血低切黏度为（10．91±2．28）mPa·S，全血高切黏度为（4．67±1．02）mPa·S，血浆黏度为（1．89±0．09）mPa·S，红细胞聚集指数2．23±0．21、红细胞变形指数0．42±0．06。两组比较有统计学意义（P〈0．05）。结论重度烧伤患者休克期常规液体复苏同时给予中药血必净治疗可明显改善血流变学的异常指标。     

The use of the compound probability density function in ultrasonic tissue characterization

Recently, a compound probability density function (pdf) was proposed to model the envelope of the ultrasonic backscattered echo from tissues. This pdf will allow local and global variations in scattering cross sections and even multiple scattering in tissue. It approximates to the Nakagami, K or Rayleigh distributions under different limiting conditions, thus making it very versatile. In this work, a new parameter associated with compound pdf, speckle factor, has been introduced to characterize the scattering conditions. The usefulness of this parameter for tissue characterization has been explored through computer simulation of ultrasonic A scans and analyses of the data collected from tissue-mimicking phantoms. Results suggest the potential applications of the compound pdf and its parameters in ultrasonic tissue characterization.     

离体甲状腺的高频超声成像和组织定征

本文用C扫高频超声显微镜对离体人体甲状腺的超声特性作了系统的研究。超声频段范围为25-55MHz。为定量对生物组织进行定征,本实验室建立一套高频超声显微镜系统,对政治客病变的离体人体甲状腺组织的三个典型的声参量进行了测量。测量结果表明：正常甲状腺的声速为1520m/s,在35MHz,超声衰减系数为3.4dB/mm,背向声散射系数为0.00157/(Srmm),而病变甲状腺滤泡性腺瘤的速为1650m/s,超声衰减系数为6.6dB/mm,约为正常的2倍,背向声散射系数为0.00387/(Srmm),比正常的大1倍半,除此之外,我们还得到正常和病变甲状腺的高频超声图象,并与组织的切片结果作了对比。     

Central role of interleukin-6 in burn induced stimulation of hepatic amino acid transport

Burn injury produces a marked and prolonged hypermetabolic state, which is characterized by accelerated hepatic amino acid metabolism and negative nitrogen balance. The effect of burn injury on hepatocyte transport of glutamine, a key substrate in gluconeogenesis and ureagenesis, was examined following the administration of a full thickness 20% total body surface scald injury. The burn injury was induced in wild-type mice, as well as two types of knockout mice: a CD-14 knockout and an interleukin-6 (IL-6) knockout. In both the wild-type and CD-14 knockout mice a latent and profound 2-fold increase in hepatocyte glutamine transport was seen. In contrast, hepatocytes isolated from IL-6 knockout mice failed to show an induction of glutamine transport after burn injury. Hepatocytes isolated from burned wild-type and CD-14 knockout mice produced significantly higher levels of IL-6 as compared to hepatocytes isolated from sham burned mice. Histologic analysis of skin isolated from wild-type mice showed a robust inflammatory response whereas skin from IL-6 deficient mice showed minimal inflammation and decreased granulation tissue. The results of this study suggest that IL-6 may play a key role in the stimulation of hepatic glutamine transport following burn injury.     

Free water content and monitoring of healing processes of skin burns studied by microwave dielectric spectroscopy in vivo

We have investigated the dielectric properties of human skin in vivo at frequencies up to 10 GHz using a time-domain reflectometry method with open-ended coaxial probes. Since gamma-dispersion results from the reorientation of free water molecules, the free water content of skin is quantitatively determined by dielectric measurements. The free water content of finger skin increased by about 10% after soaking in 37 degrees C water for 30 min, and it systematically decreased again through the drying process, as expected. Thus this analytical method has been applied to the study of skin burns. The free water content of burned human cheek skin due to hydrofluoric acid was significantly lower than that of normal skin, and the burned skin recovered through the healing process. In the case of a human hand skin burn due to heat, although the free water content was almost the same as that of normal skin at the beginning, it decreased during the healing process for the first 10 days, then began to increase. Although the number of test subjects was one for each experiment, it was shown that free water content is a good indicator for evaluating skin health and can be well monitored by dielectric spectroscopy.     

高压电烧伤家兔皮肤微循环灌流量变化及己酮可可碱的干预作用

目的观察高压电对家兔皮肤微循环灌流量(MPD)的影响并探讨己酮可可碱(PTX)的干预作用。方法将45只家兔按完全随机设计方法分为对照组、电伤组和治疗组,每组15只。电伤组和治疗组家兔用调压器和实验变压器制成高压电烧伤模型,对照组家兔接相同装置但不通电,致假伤。用激光多普勒微循环图像仪检测3组家兔伤前5min、伤后5min、1h、2h、4h、8h皮肤MPD。检测部位为左前肢和右后肢创面皮肤、右前肢和左后肢正常皮肤。结果 (1)电伤组和治疗组伤后四肢正常皮肤及创面MPD均较电伤前下降。伤后5min,电伤组及治疗组右前肢皮肤MPD分别是(0.66±0.13)V、(1.62±0.27)V,左后肢皮肤MPD分别是(0.59±0.12)V、(1.50±0.23)V,均小于伤前的(3.21±0.22)V、(3.24±0.25)V、(3.06±0.24)V、(3.01±0.22)V,在伤后各时相点中下降的幅度最大,之后虽有所回升,但一直低于伤前;伤后5min,电伤组及治疗组左前肢创面MPD分别是(0.16±0.10)V、(0.17±0.13)V,左后肢创面MPD分别是(0.18±0.11)V、(0.19±0.11)V,均小于伤前的(3.19±0.27)V、(3.23±0.24)V、(3.09±0.22)V、(3.03±0.25)V,之后持续降低。(2)电伤组和治疗组组内左右肢体比较,伤后各时相点创面MPD均明显低于对侧皮肤MPD。(3)组间同肢体同时相点与对照组比较,电伤组伤后各时相点皮肤和创面MPD均低于对照组;治疗组变化同电伤组。(4)组间同肢体同时相点治疗组与电伤组比较,治疗组伤后各时相点皮肤MPD高于电伤组;而创面MPD与电伤组差异无统计学意义。结论高压电烧伤导致家兔远隔皮肤及创面皮肤MPD下降,PTX可提高电伤后远隔皮肤MPD,对创面MPD无明显作用。     

Investigation of ultrasonic properties of PAG and MAGIC polymer gel dosimeters

Ultrasonic speed of propagation and attenuation were investigated as a function of absorbed radiation dose in PAG and MAGIC polymer gel dosimeters. Both PAG and MAGIC gel dosimeters displayed a dependence of ultrasonic parameters on absorbed dose with attenuation displaying significant changes in the dose range investigated. The ultrasonic attenuation dose sensitivity at 4 MHz in MAGIC gels was determined to be 4.7 +/- 0.3 dB m(-1) Gy(-1) and for PAG 3.9 +/- 0.3 dB m(-1) Gy(-1). Ultrasonic speed dose sensitivities were 0.178 +/- 0.006 m s(-1) Gy(-1) for MAGIC gel and -0.44 +/- 0.02 m s(-1) Gy(-1) for PAG. Density and compressional elastic modulus were investigated to explain the different sensitivities of ultrasonic speed to radiation for PAG and MAGIC gels. The different sensitivities were found to be due to differences in the compressional elastic modulus as a function of dose for the two formulations. To understand the physical phenomena underlying the increase in ultrasonic attenuation with dose, the viscoelastic properties of the gels were studied. Results suggest that at ultrasonic frequencies, attenuation in polymer gel dosimeters is primarily due to volume viscosity. It is concluded that ultrasonic attenuation significantly increases with absorbed dose. Also, the ultrasonic speed in polymer gel dosimeters is affected by changes in dosimeter elastic modulus that are likely to be a result of polymerization. It is suggested that ultrasound is a sufficiently sensitive technique for polymer gel dosimetry.