乌司他丁对促炎症因子诱导的肺微血管内皮细胞通透性和细胞因子产生的影响

目的:研究乌司他丁对炎症因子诱导的体外培养的大鼠肺微血管内皮细胞通透性和细胞因子产生的影响.方法:体外培养大鼠肺微血管内皮细胞分组进行实验:①对照组:内皮细胞培养液中加入生理盐水或乌司他丁;②炎症因子刺激组:因培养液中分别含烫伤血清、胰蛋白酶、前列腺素E2(PGE2)、缓激肽、组胺而分为5个炎症因子刺激亚组;③乌司他丁...     

Urinary excretion of histamine and methylhistamine after burns

Background

The increased vascular permeability seen after burn contribute to morbidity and mortality as it interferes with organ function and the healing process. Large efforts have been made to explore underlying pathophysiological mechanisms that generate increased vascular permeability after burns. Many different substances have been proposed as mediators of which histamine, serotonin and oxygen radicals are claimed most important. However, no specific blocker has convincingly been shown to be clinically effective. Early work has claimed increased histamine plasma-concentrations in humans after burn and data from animal models pointed at histamine as an important mediator. Modern human clinical studies investigating the role of histamine as a mediator of the generalized post burn increase in vascular permeability are lacking.

Method

We examined histamine turnover by measuring the urinary excretion of histamine and methyl histamine for 48 h after burns in 8 patients (mean total burn surface area 24%).

Results

Over time, in this time frame and compared to healthy controls we found a small increase in the excretion of histamine, but no increase of its metabolite methylhistamine.

Conclusion

Our findings do not support that histamine is an important mediator of the increased systemic vascular permeability seen after burn.     

Heparin-binding epidermal growth factor–like growth factor attenuates acute lung injury and multiorgan dysfunction after scald burn

Background

Impaired gut barrier function and acute lung injury (ALI) are significant components of the multiorgan dysfunction syndrome that accompanies severe burns. Heparin-binding epidermal growth factor–like growth factor (HB-EGF) has been shown to reduce inflammation, preserve gut barrier function, and protect the lungs from acute injury in several models of intestinal injury; however, comparable effects of HB-EGF after burn injury have never been investigated. The present studies were based on the hypothesis that HB-EGF would reduce the severity of ALI and multiorgan dysfunction after scald burns in mice.

Materials and methods

Mice were randomized to sham, burn (25% of total body surface area with full thickness dorsal scald), and burn + HB-EGF groups. The HB-EGF group was pretreated with two enteral doses of HB-EGF (1200 μg/kg/dose). Mice were resuscitated after injury and sacrificed at 8 h later. Their lungs were harvested for determination of pulmonary myeloperoxidase activity, wet:dry ratios, and terminal deoxynucleotidyl transferase dUTP nick end label and cleaved caspase 3 immunohistochemistry. Lung function was assessed using the SCIREQ Flexivent. Splenic apoptosis was quantified by Western blot for cleaved caspase 3, and intestinal permeability was measured using the everted gut sac method.

Results

Mice subjected to scald burn injury had increased lung myeloperoxidase levels, increased pulmonary and splenic apoptosis, elevated airway resistance and bronchial reactivity, and increased intestinal permeability compared with sham mice. These abnormalities were significantly attenuated in mice that were subjected to scald burn injury but treated with enteral HB-EGF.

Conclusions

These data suggest that HB-EGF protects mice from ALI after scald burn and attenuates the severity of postburn multiorgan dysfunction.     

L-alpha-glycerylphosphorylcholine reduces the microcirculatory dysfunction and nicotinamide adenine dinucleotide phosphate-oxidase type 4 induction after partial hepatic ischemia in rats

Background

We set out to investigate the microcirculatory consequences of hepatic ischemia–reperfusion (IR) injury and the effects of L-alpha-glycerylphosphorylcholine (GPC), a deacylated phospholipid derivative, on postischemic hepatocellular damage, with special emphasis on the expression of nicotinamide adenine dinucleotide phosphate oxidase type 4 (NOX4), which is predominantly expressed in hepatic microvessels.

Materials and methods

Anesthetized male Sprague–Dawley rats were subjected to 60-min ischemia of the left liver lobes and 180-min reperfusion, with or without GPC treatment (50 mg/kg intravenously 5 min before reperfusion, n = 6 each). A third group (n = 6) served as saline-treated control. Noninvasive online examination of the hepatic microcirculation was performed hourly by means of modified spectrometry. Plasma tumor necrosis factor (TNF-α), high-mobility group box 1 protein (HMGB1), plasma aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels, tissue xanthine oxidoreductase (XOR) and myeloperoxidase (MPO) activities, and expressions of NOX2 and NOX4 proteins were determined.

Results

Liver IR resulted in significant increases in NOX2 and NOX4 expressions and XOR and MPO activities, and approximately 2-fold increases in the levels of the inflammatory cytokines TNF-α and HMGB1. The microvascular blood flow and tissue oxygen saturation decreased by ∼20% from control values. GPC administration ameliorated the postischemic microcirculatory deterioration and reduced the liver necroenzyme levels significantly; the NOX4 expression, MPO activity, and HMGB1 level were also decreased, whereas the NOX2 expression, TNF-α level, and XOR activity were not influenced by GPC pretreatment.

Conclusions

NOX4 activation is a decisive component in the IR-induced microcirculatory dysfunction. Exogenous GPC ameliorates the inflammatory activation, and preserves the postischemic microvascular perfusion and liver functions, these effects being associated with a reduced hepatic expression of NOX4.     

Burn-induced organ dysfunction: Vagus nerve stimulation attenuates organ and serum cytokine levels

Introduction

The interaction of the CNS and the immune system is well known. A parasympathetic anti-inflammatory pathway has recently been described. Both electrical and pharmacological parasympathetic stimulation attenuate proinflammatory mediator generation. Burn induces abacterial cytokine generation and we sought to evaluate whether parasympathetic stimulation after experimental burn decreases cardiodepressive mediator generation.

Material and methods

A 30% TBSA full-thickness rat burn model was used. After microsurgical preparation of the cervical portion of the vagus nerve, we performed electric vagus nerve stimulation. Serum was harvested and organ samples of heart and liver were homogenized. Samples were subjected to sandwich-ELISA specific for TNF-α, IL-1β and IL-6. Heart rate measurements were done using left ventricular microcatheterization. Statistical analysis was done using Student's t-tests and analysis of variance (ANOVA).

Results

Burn induced a significant rise of TNF-α, IL-1β and IL-6 in organ homogenates and serum. After cervical vagal electrostimulation, serum and organ homogenate levels of proinflammatory cytokines were markedly reduced compared to burn controls. Left ventricular microcatheter assessment demonstrated no cardiodepressive effect of the vagal stimulation itself.

Conclusion

Our results encourage further research regarding the neuroimmunologic background of burn, possibly leading to the development of a novel therapeutic approach to burn-induced organ dysfunction and immunodysregulation.     

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.     

Tumor necrosis factor-alpha preconditioning attenuates liver ischemia/reperfusion injury through preserving sarco/endoplasmic reticulum calcium-ATPase function

Background

Tumor necrosis factor-alpha (TNF-α) is a multifunctional cytokine. In this study, we investigated the role of TNF-α preconditioning in liver ischemia/reperfusion injury (IRI).

Methods

After IRI, serum alanine aminotransferase, protein levels of SERCA-3, and Caspase-3 in liver were analyzed. In vitro study, primary hepatocytes were isolated from mice and cultured in hypoxic media with or without TNF-α. The levels of SERCA-3, Caspase-3, and intracellular calcium were evaluated after 24-h incubation. In addition, protease inhibitors were adopted to determine the role of SERCA-3 in TNF-α preconditioning.

Results

Low dose of TNF-α preconditioning protected liver from IRI, which was described by reduced serum alanine aminotransferase, Capase-3, and elevated SERCA-3 compared with the animals without TNF-α treatment. The in vitro test confirmed the protective effect of TNF-α through maintaining homeostasis of intracellular calcium. However, the effect of TNF-α was deprived by protease inhibitors.

Conclusions

In this study, we demonstrated that IRI reduced SERCA-3 expression in liver. Low dose of TNF-α preconditioning protected against SERCA-3 reducing, promoted intercellular calcium storage, and attenuated liver IRI.     

Evaluation of soluble CD14 subtype (presepsin) in burn sepsis

Background

Diagnosing sepsis is difficult in burn patients because of the inflammatory mediators that alter postburn metabolic profile. Here, we compare a new marker presepsin with procalcitonin (PCT), c-reactive protein (CRP) and white blood cell (WBC) in diagnosis and follow up of sepsis in burn patients.

Methods

Patients admitted to burn center of our institute were prospectively investigated. Presepsin, PCT, CRP and WBC levels were measured at admission and every 6 h for first day and daily thereafter. At all timing samples, patients were classified as sepsis or non-sepsis according to the current American Burn Association Consensus Criteria (ABA) 2007.

Result

37 adult patients were evaluated. A total data of 611 time points were supplied. Sepsis time points differ significantly from non-sepsis in presepsin (p < 0.0001), PCT (p = 0.0012) and CRP (p < 0.0001) levels. Non-surviving patient results differ significantly from survivors in presepsin (p < 0.0001), PCT (p = 0.0210) and CRP (p = 0.0008). AUC-ROC % values for diagnosing sepsis were 83.4% for presepsin, 84.7% for PCT, 81.9% for CRP and 50.8% for WBC. Sepsis patients had significantly different presepsin, CRP and WBC but not PCT levels on their first day of sepsis compared to previous days.

Conclusion

Plasma presepsin levels have comparable performance in burn sepsis.     

A prospective randomised clinical pilot study to compare the effectiveness of Biobrane® synthetic wound dressing, with or without autologous cell suspension, to the local standard treatment regimen in paediatric scald injuries

Background

Scald is the most common cause of burn in children in Australia. The time taken by the burn wound to heal impacts on scar outcome. Commonly scald injuries are treated conservatively; in our unit the practice is that if healing does not occur within 10 days, surgery is used to aid healing with the aim of improving scar outcome. This randomised controlled pilot study compares early treatment regimens to facilitate tissue salvage and reduce the incidence of definitive surgery at 10 days following scald injury.

Methods

All paediatric patients with partial thickness scald injury were clinically assessed between July 1, 2009 and June 30, 2010. A burn of 2% TBSAB or more and deemed not to heal within 10 days, were considered for the trial. These patients were randomised to one of three treatment arms: the local standard treatment (Intrasite™, Acticoat™ and Duoderm^® dressings every 2–3 days) with surgery at 10 days, Biobrane^® only or Biobrane^® and autologous cell suspension using the ReCell^® kit. The primary outcome was surgery performed after 10 days; secondary outcomes were rates of healing, pain experienced, and scar outcomes.

Results

15% of scald presentations in the 12 month period met the eligibility criteria. 13 patients were recruited into the pilot study; early intervention was associated with a decreased time to healing with fewer dressing changes, less pain and better scar outcomes.

Conclusion

Investment of surgical resources in the acute stages within 4 days of injury saved on nursing time, dressing, analgesic and scar management costs.     

Correlation between circulating proteasome activity,total protein and c-reactive protein levels following burn in children

Aim of the study

To characterize burn-induced changes following burn in children by analyzing circulating proteasome (c-proteasome) activity in the plasma in correlation with total protein and c-reactive protein levels in the plasma, and the severity of the burn.

Methods

Fifty consecutive children scalded by hot water who were managed at the Department of Pediatric Surgery after primarily presenting with burns in 4–20% TBSA were included into the study. The children were aged 9 months up to 14 years (mean age 2.5 ± 1 years). Patients were divided into groups according to the pediatric injury severity score used by American Burns Association. Plasma proteasome activity was assessed using Suc-Leu-Leu-Val-Tyr-AMC peptide substrate, 2–6 h, 12–16 h, 3 days, 5 days, and 7 days after injury. 20 healthy children consecutively admitted for planned inguinal hernia repair served as controls.

Results

Statistically significant elevation of plasma c-proteasome activity was noted in all groups of burned children 12–16 h after the injury. We found a strong negative correlation of c-proteasome activity with total protein levels, and positive correlation with CRP levels 12–16 h after burn. We also found stronger correlation between c-proteasome activity and severity of burn, than CRP level and severity of burn 12–16 h, and 3 days after the burn. Correlations were statistically significant.

Conclusions

This study characterized circulating 20S proteasome activity levels after burn. C-proteasome activity elevate after burn and correlate negatively with plasma total protein level, thus plasma 20S proteasome activity could be additional biomarker of tissue damage in burn in pediatric population.     

Skeletal muscle satellite cell activation following cutaneous burn in rats

Background

Cutaneous burn distant from skeletal muscles induces atrophy; however, its effect on muscle stem cells resident in skeletal muscle (satellite cells) distal to burn is not known.

Methods

Satellite cell activation was measured in predominantly fast-twitch [tibialis anterior, extensor digitorum longus (EDL), plantaris, and gastrocnemius] and slow-twitch (soleus) muscles of rats that received either 40% total body surface area full-thickness scald burn or sham burn to the trunk area by determining bromodeoxyuridine incorporation, MyoD, and Pax7 immunohistochemistry in vivo ≤48 h after burn. To determine the effects of circulating factors on satellite cell activation, satellite cell cultures were treated with serum from sham or burn rats.

Results

In vivo activation of satellite cells was increased in fast muscles isolated from burn as compared to sham animals, whereas a significant response was not seen in slow muscles. Serum taken from animals in the burn group increased the activation of satellite cells isolated from both sham and burn animals in vitro, suggesting that circulating factors have the potential to increase satellite cell activation following burn.

Conclusions

Increases in satellite cell activation in muscles distal to burn are fiber-type-dependent, and circulating factors may play a role in the activation of satellite cells following burn. A better understanding of the impact of burn on satellite cell functionality will allow us to identify the cellular mechanisms of long-term muscle atrophy.     

Role of neutrophil elastase in lung injury induced by burn–blast combined injury in rats

Objective

Neutrophil elastase (NE) takes part in the pathogenesis of acute lung injury. However, its role in lung injury of burn–blast combined injury is unclear. Our objective was to assess the role of NE, and effect of sivelestat, a specific NE inhibitor, in lung injury induced by burn–blast combined injury in rats.

Methods

One hundred and sixty male Sprague-Dawley rats were randomly subjected to burn–blast combined injury (BB) group, burn–blast combined injury plus sivelestat treatment (S) group or control (C) group. Blood gas, protein concentration and NE activity in bronchoalveolar lavage fluid (BALF), pulmonary myeloperoxidase (MPO) activity, serum concentrations of TNF-α and IL-8, etc. were investigated from 0 h to 7 d post-injury.

Results

In BB group, PaO₂ decreased, while NE activity in BALF, total protein concentration in BALF, pulmonary MPO activity and W/D ratio, serum concentrations of TNF-α and IL-8 increased with neutrophil infiltration, progressive bleeding and pulmonary oedema. Compared with BB group, sivelestat treatment decreased the NE activity and ameliorated the above indexes.

Conclusion

Sivelestat, exerts a protective effect in lung injury after burn–blast combined injury through inhibiting NE activity to decrease pulmonary vascular permeability, neutrophil sequestration, and production of TNF-α and IL-8.     

Neutrophil gelatinase associated lipocalin as an indicator of acute kidney injury and inflammation in burned children

Introduction

Neutrophil gelatinase associated lipocalin (NGAL) is a novel predictor of acute kidney injury (AKI), which increases with inflammation. We aimed to assess whether serum NGAL (SNGAL) and urine NGAL (UNGAL) can predict AKI in burned children.

Methods

Patients were referred within the 12 h of burn to our center. Serum samples for SNGAL, C-reactive protein (CRP), procalcitonin (PCT) and urine for UNGAL, microalbumine (Umalb), creatinine (Ucr) were obtained at both admission and the 5th day after burn. Blood urea nitrogen (BUN) and serum creatinine (Scr) were examined daily.

Results

Twenty-two subjects were enrolled and six (27.2%) of them developed AKI within the 48 h of injury. Burn size and abbreviated burn severity index (ABSI) were significantly increased in patients with AKI. CRP, PCT, SNGAL and UNGAL levels at admission and day 5 were significantly higher in patients with AKI than in those without AKI and controls. Scr was not significant between AKI and non-AKI groups at hospital days 1 and 5. A SNGAL level of 315 ng/ml and a UNGAL level of 100 ng/ml were determined as predictive cut-off values of AKI at admission (sensitivity and specificity: 71.4%, 83.3% and 93.3%, 93.7%, respectively). SNGAL and UNGAL were positively correlated with CRP, PCT, ABSI and Umalb/Ucr.

Conclusion

SNGAL and UNGAL are good early predictors of AKI in children with severe burn. NGAL might reflect the severity of burn insult and also could be used as an indicator of inflammation in burn children.     

The direct hospitalisation costs of paediatric scalds: 2-Year results of a prospective case series

Objective

To reveal the characteristic and distribution of length of hospital stay (LOS) and direct hospitalisation costs of paediatric scald.

Methods

A prospective case series observation was performed from January 2005 to December 2006 at the Burn Center, Changhai Hospital, Shanghai, China. The information, such as demographics, clinical diagnosis and treatments since admission, of the paediatric scald patients included in the series was recorded. The direct cost of a treatment event was recorded into the price system when it was incurred. All cost data were summarised on completion of the study. The distribution of LOS and the hospitalisation costs were recorded by gender, age, total burn area, depth of burn, blood transfusion and patterns of treatment. Mann–Whitney signed-rank test was used to assess the differences between continuous, non-normally distributed variables, and multiple linear regression was used to model LOS and direct hospitalisation costs. Statistical analyses were undertaken with SPSS 15.0 statistical software.

Results

Patients aged 3 years or less accounted for more than half of the total LOS and hospitalisation costs, patients with burn area less than 10%TBSA (total burn surface area) accounted for more than 70% of the total LOS and more than half of the hospitalisation costs and patients with second-degree burn accounted for more than 78% of the total LOS and hospitalisation costs. Depth of burn, area of burn, patterns of treatment and blood transfusion were independent predictors of LOS; whereas LOS, area of burn and blood transfusion were independent predictors of hospitalisation costs.

Conclusion

Paediatric scalds have particular characteristics in terms of distribution of LOS and direct hospitalisation costs and the factors influencing them. The data presented in this study should assist burn care practitioners and hospital epidemiologists estimate and compare the economic burden of paediatric burns at other institutions; it may also be useful in resource allocation and cost-effectiveness analysis of treatment versus prevention strategies.     

Determinants of burn first aid knowledge: Cross-sectional study

Introduction

This study investigated demographic factors, experience of burn/care and first aid course attendance as factors influencing burn first aid knowledge.

Methods

A cross-sectional study was undertaken using convenience sampling of members of sporting and recreation clubs. The main outcome measure was the proportion of correct responses to multiple-choice questions relating to four burn scenarios: (1) scald, (2) contact burn, (3) ignited clothing, and (4) chemical burn.

Results

A total of 2602 responses were obtained. Large gaps (30–50% incorrect answers) were identified in burn first aid knowledge across all scenarios. 15% more individuals gave correct answers if they had attended a first aid course compared to those who had not (p < 0.0001); this proportion increased if the course was undertaken within the previous five years (p < 0.0001) or contained a burns-specific component (p < 0.0001). Males and younger (≤25 years) and older (≥65 years) age-groups had relatively lower levels of burn first aid knowledge. Gender and age were significant predictors of first aid course attendance, with males and younger (≤25 years) and older (≥65 years) age-groups less likely to have attended a first aid course.

Conclusion

In this sample, first aid training undertaken within the last 5 years with a specific burns component was associated with enhanced burn first aid knowledge.     

Epidemiology of operative burns at Kijabe Hospital from 2006 to 2010: Pilot study of a web-based tool for creation of the Kenya Burn Repository

Introduction

In order to implement effective burn prevention strategies, the WHO has called for improved data collection to better characterize burn injuries in low and middle income countries (LMIC). This study was designed to gather information on burn injury in Kenya and to test a model for such data collection.

Methods

The study was designed as a retrospective case series study utilizing an electronic data collection tool to assess the scope of burn injuries requiring operation at Kijabe Hospital from January 2006 to May 2010. Data were entered into a web-based tool to test its utility as the potential Kenya Burn Repository (KBR).

Results

174 patients were included. The median age was 10 years. There was a male predominance (59% vs. 41%). Findings included that timing of presentation was associated with burn etiology (p = 0.009). Length of stay (LOS) was associated with burn etiology (p < 0.001). Etiology differed depending on the age group, with scald being most prominent in children (p = 0.002).

Conclusions

Burn injuries in Kenya show similarities with other LMIC in etiology and pediatric predominance. Late presentation for care and prolonged LOS are areas for further investigation. The web-based database is an effective tool for data collection and international collaboration.     

Effect of Poloxamer 188 on deepening of deep second-degree burn wounds in the early stage

Objective

To discuss the effect of Poloxamer 188 (P188) on deepening of deep second-degree burn wounds in the early stage after burn.

Methods

We divided Wistar rats with deep second-degree burn wounds on the backs thereof into two groups, then intravenously injected P188 for the treatment group and intravenously injecting physiological saline for the control group, detecting the activity of Na⁺–K⁺–adenosine triphosphatase (Na⁺–K⁺–ATPase), myeloperoxidase (MPO) and the content of malonaldehyde (MDA) and succinic dehydrogenase (SDH) in the burn wound, and showing the degree of necrosis in the wound by haematoxylin–eosin (HE) and proliferating cell nuclear antigen (PCNA) immunohistochemical staining.

Results

In the control group and treatment group, the activity of SDH and Na⁺–K⁺–ATPase dropped to the lowest point 24 h after the burn took place, and then increased gradually, but was still far lower than the normal level at the furthest time point. At 24 h after burn, activity of SDH and Na⁺–K⁺–ATPase in the treatment group was higher than that of the control group (P < 0.05); the activity of MPO of the control group reached the highest point at 24 h while that of MPO of the treatment group reached the highest point after 48 h; later, that of MPO of both groups decreased, but was still higher than the normal level. Compared with the highest values of the activity of MPO of both groups, that of the control group was higher than that of the treatment group (p < 0.05); the contents of MDA of both groups kept increasing after the burn; 72 h later, that of the control group was higher than that of the treatment group (p < 0.05). HE and PCNA staining showed progressive damage of the wound in the treatment group, which was decreased with treatment, particularly at the early stages.

Conclusion

Systemic application of P188 on deep second-degree burn wounds at the early stage may alleviate wound deepening, whose mechanism may be related to timely sealing up the damaged cell membrane and inhibiting the inflammatory reaction.