MRSA气溶胶诱导烫伤SKH-1无毛小鼠皮肤感染合并肺炎模型

目的 探讨烫伤条件下,建立MRSA气溶胶致SKH-1无毛小鼠皮肤感染合并肺炎模型的方法及其评价指标。方法 48只SKH-1无毛小鼠,随机分成PBS对照组,单纯感染组和烫伤合并感染组。合并感染组小鼠皮肤烫伤后,MRSA(ST-239)气溶胶呼吸道感染,采用体重、血常规、菌血症率、皮肤和脏器荷菌量、病理组织学变化和分子生物学等指标对模型进行综合评价。结果 与其他两组相比,合并感染组小鼠体重下降明显;白细胞数显著增多;菌血症率达100%;皮肤和肺荷菌量较高,分别达108CFU/g和106CFU/g;镜下观察皮肤和肺炎症病变明显;免疫组化结果显示皮肤组织内CD138呈阳性表达;multi-PCR测定感染组织内nuc和mecA基因均为阳性。结论 SKH-1无毛小鼠烫伤再辅以MRSA气雾攻击的方式,可成功建立能够模拟临床上烧烫伤患者继发MRSA肺炎的动物模型,此模型对于抗MRSA药物药效评价研究具有重要临床应用价值。     

Steam inhalation: More harm than good? Perspective from a UK burns centre

IntroductionSteam inhalation is common practice in UK households for coryzal symptoms in adults and children. Steam inhalation has the potential to and has caused significant scald injuries, predominantly due to unintentional contact with the hot water used.MethodsThe authors used electronic health records to retrospectively identify all patients admitted with scald injuries secondary to steam inhalation over a 2-year period from January 2018-December 2019 at Chelsea and Westminster Hospital, a regional burns centre. Data collected included patient demographics, mechanism of burn, as well as burn size, depth, treatment and any associated complications. An International Burns Injury Database enquiry assessed the national prevalence steam inhalation scalds over the same time period.Results19 adult and paediatric patients were identified in our centre over a 2-year period, with an age range of 2 weeks to 91 years old. The majority (16/19, 84%) of patients received burns to their lower body, with three patients receiving burns to their chest and/or upper limbs. Six patients underwent surgery, 98 clinic appointments were utilised and the total length of hospital stay was 83 days. The estimated total cost of treating these 19 patients was over £31,872. Nationally, 201 cases were identified between Jan 2018–Dec 2019.ConclusionsScald injuries secondary to steam inhalation have a significant impact both in terms of hospital stay and cost. Since this study captured only patients admitted to hospital, the true negative impact of steam inhalation is likely to be much higher than calculated. Better public awareness on the risks of steam inhalation and primary prevention policies could reduce the frequency of such injuries.     

驻极体对烫伤大鼠皮肤微血管壁通透性变化的影响

通过检测烫伤部位皮肤组织匀浆中荧光标记的白蛋白的含量，观察了大鼠烫伤６，１２和２４ｈ后皮肤微血管壁通透性的变化以及－１００，－２５０，－５００，－７５０和－１０００Ｖ驻极体对这种变化的影响。结果指出：（１）烫伤后１２ｈ，大鼠皮肤血管壁通透性明显高于对照组（Ｐ〈０．０１），－２５０，－５００和－７５０Ｖ驻极体治疗组大鼠的血管壁通透性明显低于烫伤组（Ｐ〈０．０５），－１０００Ｖ驻极体治疗组皮肤血管壁通     

电针足三里穴对大鼠烫伤早期胃和小肠黏膜血流量的影响

目的:研究电针刺激足三里穴对大鼠烫伤休克早期胃和小肠黏膜血流量的影响。方法:35只健康雄性Wistar大鼠随机分为7组:假烫组(C)、烫伤2 h组(S_2)、烫伤6h组(S_6)、烫伤 电针足三里穴2 h组(SE_2)、烫伤 电针足三里穴6h组(SE_6)、烫伤 电针非经非穴2h组(SSE_2)、烫伤 电针非经非穴6 h组(SSE_6),每组5只。烫伤组大鼠均造成背部35%TBSAⅢ度烫伤(100℃沸水,15s)。烫伤 电针组大鼠于烫伤后30 min开始电针刺激足三里穴或非经非穴(频率2～100 Hz,强度2～3 mA,时间1h)。假烫组于术后2 h、烫伤组于烫伤后2 h和6 h用激光多普勒血流仪测定胃和小肠黏膜血流量。结果:烫伤后大鼠胃和小肠黏膜血流量均较假烫组显著降低(P<0.01),电针刺激足三里穴各组大鼠胃和小肠黏膜血流量均显著回升,显著高于烫伤组和烫伤 电针非经非穴组(P<0.05)。结论:电针足三里穴能显著改善大鼠烫伤休克早期胃和小肠黏膜血流量。     

大鼠皮肤急性深Ⅱ度β射线损伤创面愈合过程中的对比观察

目的观察大鼠皮肤急性深Ⅱ度β射线损伤创面自然愈合过程中β_1整合素表达阳性细胞的动态变化,探讨急性β射线皮肤损伤创面的难愈机制。方法将96只SD大鼠随机分为实验组(48只)与对照组(48只),实验组建立大鼠皮肤急性深Ⅱ度β射线损伤创面模型;对照组建立大鼠皮肤深Ⅱ度热力烫伤创面模型。分别于伤后1 d、3 d、7 d、14 d、21d、28 d、35 d记录创面变化,并取创面组织标本,行HE染色和免疫组化染色,观察创面愈合过程中的组织变化和β_1整合素阳性细胞的变化。结果实验组大鼠创面愈合时间较对照组长,经统计学分析,差异有统计学意义(P0.01);通过对β_1整合素的检测发现,照射及烫伤后1 d、3 d、7 d、14 d、21 d的β_1整合素阳性细胞IOD值比较,差异有统计学意义(P0.05),对照射及烫伤后28 d、35d的β_1整合素阳性细胞IOD值进行比较,差异无统计学意义(P0.05)。结论皮肤急性深Ⅱ度β射线损伤创面愈合时间相对缓慢,且在愈合过程中β_1整合素阳性细胞增殖分化延迟,可能是皮肤急性深Ⅱ度β射线损伤创面延迟愈合的原因之一     

大剂量维生素C对肠黏膜屏障的保护作用

目的　研究大剂量维生素C对烫伤后大鼠肠黏膜屏障的保护作用。方法　选用大鼠烫伤模型 ,烫伤面积为30 % ,深度为Ⅲ度。大鼠随机分为 4组 ,即烫伤组、模拟烫伤组、维生素C治疗组和安慰剂治疗组。观察维生素C对烫伤大鼠肠道细菌易位、血浆内毒素水平和肠黏膜内超氧化物歧化酶 (SOD)的影响。结果　严重烫伤可致肠黏膜屏障破坏 ,肠道内细菌易位至肝、脾、肠系膜淋巴结 ;维生素C可降低细菌易位的发生率和易位量 ,与烫伤组有显著差异 (P <0 0 5 ) ;且烫伤可致血浆内毒素水平明显升高 ,尤以烫伤后 10h显著 ,而 2 4h后有所下降 ;维生素C可明显抑制肠道内内毒素的吸收 (P <0 0 1) ;此外 ,维生素C对烫伤后肠黏膜内氧自由基有明显的清除作用。结论　维生素C对烫伤大鼠肠黏膜屏障有明显的保护作用 ,能抑制肠道细菌易位和肠道内内毒素吸收。     

Characterization of the release of heated and pressurized water from a pressure cooker

Recently, self-heating consumer pressure cookers have found reinvigorated use with consumers wanting faster, more convenient, and healthier cooking. With the increased popularity, injury reports have also increased. Hazards associated with dispersion from pressurized vessels, although qualitatively understood through elementary scientific principles, have not been experimentally characterized in the literature, nor has the human ability to respond to a sudden dispersion of contents been directly reviewed. This study examined the consequence of volume and pressure on the dispersion of hot water from a typical 6 quart pressure cooker contacting a clothed user. This study found that both pressure and volume level influence the dispersion of contents after lid opening as well as the lid departure speed. Results also indicate that the speed of both the departing lid and the dispersing liquid occurred quicker than a bystander, within arm’s reach, can consciously react to avoid or to shield themselves from the hot contents. The results confirmed analytical analyses found in the literature that a single layer cotton shirt (e.g., a t-shirt) saturated with water is more likely to trap hot liquid, increasing the likelihood of a more severe burn in that area due to prolonged skin contact.     

烫伤家兔球结膜微血管管径变化

目的:观察严重烫伤后家兔球结膜微血管管径的变化规律及特点。方法:30只成年健康家兔,采用自身前后对照和组间对照,观察烫伤后不同时相球结膜微血管管径的动态变化,并对所得资料进行比较分析。结果:烫伤组家兔球结膜微动、静脉管径与对照组存在显著性差异(P<0.05),且以烫伤后2h内变化最明显。变化规律为:结膜微动、静脉先收缩后扩张,收缩时程短,扩张时程长;烫伤初期球结膜鼻侧与颞侧微血管管径变化不同步。结论:严重烫伤可致家兔球结膜微血管管径发生显著改变。     

烫伤延迟复苏后细胞凋亡对肠粘膜通透性的影响

目的：探讨烫伤延迟复苏后肠粘膜细胞凋亡对其通透性的影响。方法：150只Wistar大鼠分为立即复苏(ER)、延迟复苏(DR)，N—乙酰半胱氨酸(NAC)和别嘌呤醇(Allo)治疗组及正常对照。采用DNA片段百分率(ap％)、电泳、TUNEL法观察回肠粘膜凋亡情况；并测定门静脉D—乳酸、内毒素以观察肠粘膜通透性改变。结果：伤后DR组ap％均显著高于ER组。NAC组ap％显著低于DR组。电泳、TUNEL法均观察到肠粘膜凋亡发生；ap％与D—乳酸、内毒素变化呈显著正相关。结论：烫伤延迟复苏后肠粘膜发生病理性凋亡，与其通透性变化密切相关；NAC可显著减轻延迟复苏所致肠粘膜细胞凋亡。     

Assessing paediatric scald injuries using Laser Speckle Contrast Imaging

Background

The use of objective methods for assessment of burns is limited. Laser Speckle Contrast Imaging (LSCI) is a non-invasive technique for instant measurement of tissue perfusion, making it potentially valuable for early prediction of burn wound outcome.

Aim

To evaluate the influence of technical factors on perfusion and to measure perfusion in burns 0–14 days post-burn and compare this with the outcome of the burn wound at 14 days after burn.

Method

The effect of room light, camera distance and camera angle was studied using a suspension of polystyrene particles. LSCI measurements were performed on 45 scald burns and 32 uninjured areas 0–14 days after burn.

Result

Technical factors had no clinically relevant effect on measured perfusion. Burns that healed within 14 days had a higher perfusion during the first week post-burn than burns that healed after 14 days or underwent surgery. The difference in perfusion was largest 4–7 days after burn.

Conclusion

LSCI allows for robust, instant measurement of burns and can easily be applied in a clinical setting. Differences in perfusion during the first week post-burn are related to the outcome after 14 days.