Burn injury induces histopathological changes and cell proliferation in liver of rats

Correlation of thermal burn hepatic dysfunction with outcomes

INTRODUCTION

Organ dysfunction and failure increase the morbidity and mortality following major burn. Alteration of liver morphology and function is common following major burns; however, it has not received much attention. In this study we have assessed the impact of thermal burn on liver in relation with mortality.

MATERIAL AND METHODS

55 patients (33 female and 22 males) with TBSA 10-90% and age ranged from 18 to 75 years were included. A bed side serial ultrasonography to assess the volume of liver and liver function tests was done on the 2nd, 9th and 16th day following burn. Baseline demographic and clinical information such as age, gender, burn size and outcome of patient were also collected.

RESULTS -

8 patients died during 2nd week following burn and 47 survived. The mean TBSA for survivors was 37% and for non survivors 80%. Mean liver volume in survivors steadily decreased from 1693.70 cm3 to 1631.31 cm3 over 3 weeks. Mean liver volume in non- survivors steadily increased from 1855.88 cm3 to 2028.50 cm3 over 2 weeks. Liver function test in survivors steadily improved while in non survivors it deteriorated over 2 weeks.

CONCLUSION

There is a correlation between altered liver morphology and function with mortality among severely burnt patients however liver volume did not show statistical significance. A decreasing trend of liver dysfunction parameters and hepatomegaly following burn is associated with good prognosis.

Description of Aspartate Aminotransferase and Alanine Aminotransferase in Burn Patients at the Burn Unit of Dr. Hasan Sadikin General Hospital (Rshs) Bandung

Burn injury is trauma with several metabolic reactions including hepatocytes that can cause apoptosis and necrosis. Proliferation occurs to compensate for this reaction but complicates with the loss of protein of the injury. The aim of this study is to describe the level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in burn injury. This study was a descriptive retrospective design using secondary data from medical records of patients at the Burns Unit of Dr. Hasan Sadikin Hospital Bandung (RSHS) in the period August 2017 to July 2019. Total samples in this study were 116 people. Normal level of AST and ALT was found in 23 people (19.8%), elevation of AST in 31 people (26.7%), elevation of ALT in 5 people (4.3%) and elevation of both AST and ALT in 57 people (41.3%). Increased levels of AST and ALT mostly occurred in men (51%), aged 45 years (56%), with injury due to electricity (26%), 20-29% burn area (32%), and occurred in the first week of wound onset. Most cases of burn injury showed increasing levels of AST and ALT. This might be due to the metabolism of hepatocytes in burn cases. Elevation of AST and ALT was mainly found in burn injury cases at RSHS notably in the first week of onset. Further research is needed to verify the relation of this condition. Elevated levels of AST and ALT should be the consideration of clinicians in giving therapy.

Effects of resveratrol topical ointment on wound healing of full-thickness cutaneous burns in albino rats

OBJECTIVE

In this study, the effects of resveratrol topical ointment on wound contraction and histopathology of full-thickness cutaneous burn wounds were evaluated.

METHOD

Adult albino rats were grouped into four equal-sized groups of 15 rats each, as follows: Group A-no wound, no treatment (control); Group B-1% silver sulphadiazine; Group C-5% resveratrol, and Group D-wound without treatment (control). A burn wound measuring 23.5mm was created on the skin at the dorsum of all rats in groups B-D after shaving. The percentage of wound contraction was measured using a digital Vernier Caliper on days 1, 3, 5, 7, 10, 14, 16, 18 and 21, post-wounding. From each group, five rats were then euthanised and tissue samples of the skin, liver and kidney were collected in 10% buffered formalin for histopathology.

RESULTS

The percentage of wound contraction was significant (p<0.05) on 7, 14 and 18 days post treatment. Histopathologically, 5% resveratrol topical ointment application resulted in a thicker epidermis with neovascularisation and an increased collagen distribution. Resveratrol topical ointment ameliorated the extent of hepatocellular and nephrotubular injuries following burn-induced hepatocellular and acute kidney injuries.

CONCLUSION

In this study, topical application of 5% resveratrol ointment appeared to enhance burn wound healing by increasing the rate of wound contraction through collagen fibre synthesis, granulation tissue formation and epithelial regeneration.

Characteristics And Outcome Influence Of Increased Plasma Triglyceride Level In Severely Burned Adult Patients

The aims of this study were to investigate the profile of serum triglyceride level and its influence on outcomes in adult patients with severe burns. An observational study was conducted on 62 patients with burn extent from and over 20% TBSA. Results indicated that serum triglyceride level steadily increased from 1.9mmo/l on the 3rd day to 2.5 mmol/l on the 14th day before reducing on the 21st day after burn. Remarkably higher triglyceride level was seen in patients with full thickness burn area >20% TBSA and in inhalation injury (p < .05). Liver size significantly increased over time and was greater in increased triglyceride patients, but the difference was not significant (p > .05). In addition, patients with elevated serum triglyceride level had significantly higher rates of multiple organ failure and death compared with the remaining group. Further studies need to be conducted to understand and determine intervention for increased plasma triglyceride levels in severely burned patients.

Minimal Effects of Intravenous Administration of Xenogeneic Adipose Derived Stem Cells on Organ Function in a Porcine 40%TBSA Burn Model

Adipose stem cells (ASCs) have shown therapeutic promise for various conditions, including burn injury. While ASCs have immunomodulatory properties, concerns exist over pro-coagulant activity after intravenous (IV) administration. In the present study, we examined IV human ASC delivery in terms of coagulation, organ function, and inflammation in a 40% total body surface area (TBSA) swine burn model. Anesthetized female Yorkshire swine were burned and randomized to receive 15ml/kg Lactated Ringer's containing: no ASCs; a low dose (5x10 5 ASCs/kg), or a high dose (5x10 6 ASCs/kg). For biochemical analysis, blood was collected at baseline (BL), 3, 6, 12, and 24 hours post-burn, while kidney and liver tissue was collected post-euthanasia. A significant, but transient, effect of ASCs was seen on prothrombin times and INR, wherein low doses revealed slight hypercoagulation. Burns increased partial thromboplastin time, fibrinogen, and d-dimer levels, which was unchanged with ASC administration. ASCs tended to exacerbate increases in bilirubin at 3 hours, but this didn't reach statistical significance. A significant effect of ASCs on creatinine and BUN was seen, wherein low doses elevated levels at 24 hours (creatinine, p=0.0012; BUN, p=0.0195). Hepatic and renal TUNEL staining were similar for all groups. A dose-dependent decrease in IL-8 was observed, while low doses significantly increased IL-1RA at 3 (p=0.050), IL-12 at 12 (p=0.021) and IL-6 at 24 hours post-burn (p=0.035). IV administration of xenogeneic ASCs slightly increased coagulation, but effects on burn-induced renal and hepatic dysfunction effects were minimal. Despite some significant immunomodulation, organ dysfunction effects were modest. Collectively, this study provides evidence to be skeptical about xenogeneic ASC administration in regards to burn.

SS-31 ameliorates hepatic injury in rats subjected to severe burns plus delayed resuscitation via inhibiting the mtDNA/STING pathway in Kupffer cells

Hepatic injury is common in patients who suffer from severe burns plus delayed resuscitation (B + DR). Stimulator of interferon genes (STING) is primarily expressed in Kupffer cells (KCs). We demonstrated that B + DR caused hepatic injury and oxidative stress. Reactive oxygen species (ROS) damage mitochondrial membranes in hepatocytes, leading to the release of mitochondrial DNA (mtDNA) into the hepatocyte cytosol and the circulation. The damaged hepatocytes then activate the mtDNA/STING pathway in KCs and trigger KCs polarization towards pro-inflammatory phenotype. SS-31 is a strong antioxidant that specifically concentrates in the inner mitochondrial membrane. SS-31 prevented hepatic injury by neutralizing ROS, inhibiting the release of mtDNA, protecting hepatocyte mitochondria, suppressing the activation of the mtDNA/STING pathway and inhibiting KCs polarization into pro-inflammatory phenotype.

The Influence of Obesity on Treatment and Outcome of Severely Burned Patients

Obesity and the related medical, social, and economic impacts are relevant multifactorial and chronic conditions that also have a meaningful impact on outcomes following a severe injury, including burns. In addition to burn-specific difficulties, such as adequate hypermetabolic response, fluid resuscitation, and early wound coverage, obese patients also present with common comorbidities, such as arterial hypertension, diabetes mellitus, or nonalcoholic fatty liver disease. In addition, the pathophysiologic response to severe burns can be enhanced. Besides the increased morbidity and mortality compared to burn patients with normal weight, obese patients present a challenge in fluid resuscitation, perioperative management, and difficulties in wound healing. The present work is an in-depth review of the current understanding of the influence of obesity on the management and outcome of severe burns.

Protective Effects of Melatonin against Severe Burn-Induced Distant Organ Injury: A Systematic Review and Meta-Analysis of Experimental Studies

Extensive burns result in a local wound response and distant-organ injury (DOI) caused by oxidative-stress and inflammation. Melatonin (MT) shows promise in alleviating oxidative-stress and inflammation, but its role in thermal injury is largely unexplored. The present systematic review and meta-analysis were designed to assess the effects of MT on oxidative-stress and inflammatory markers against severe burn-induced DOI. Mean difference (MD)/standard mean difference (SMD) with 95% confidence interval (CI) were estimated using fixed-effect/random-effects models. Eighteen experimental studies met the inclusion criteria. Compared with the control group, MT significantly decreased the levels of malondialdehyde (SMD, −1.03; 95% CI, −1.30, −0.76, p < 0.00001) and 4-hydroxynonenal (MD, −1.06; 95% CI, −1.57, −0.56, p < 0.0001). Additionally, MT increased the levels of glutathione (SMD, 1.94; 95% CI, 1.27, 2.61, p < 0.00001) and superoxide-dismutase (SMD, 0.76; 95% CI, 0.08, 1.45, p = 0.03). Finally, MT significantly decreased the levels of tumor necrosis factor-α (SMD, −1.34; 95% CI, −1.92 to −0.77; p < 0.00001) and C-reactive protein (MD, −12.67; 95% CI, −16.72 to −8.62; p < 0.00001). Meta-analysis indicates that severe burn followed by immediate MT (10 mg/kg) intervention shows significant beneficial effects after 24-h against DOI by regulating oxidative-stress and the inflammatory response.

Hepatic inflammation after burn injury is associated with necroptotic cell death signaling

BACKGROUND

Burn injury still has a high attributable mortality. The elevated mortality rate of severe burns is still concerning. Hepatic inflammation and injury are common after burns and are associated with poor outcomes. Necroptosis is a programmed cell death linked with inflammation. Thus, assessing necroptotic pathways in the liver can lead to new therapeutic modalities to improve mortality after severe burns.

METHODS

Mice underwent 15% total body surface area burn or sham injury. Three hours after burn, the mice were euthanized to collect blood and livers. Histology, injury markers, genes expression, and tissue protein levels were compared between groups.

RESULTS

Compared with sham, burned mice had heightened liver inflammatory cell infiltration and edema. Serum aspartate aminotransferase and alanine aminotransferase were increased by 4.9- and 3.4-fold, respectively, in burned mice relative to sham (p < 0.05). Expression of tumor necrosis factor α, interleukin-6, interleukin-1β, and CXCL1 (KC) genes were elevated in livers of burned mice by 10-, 86-, 10-, and 828-fold, respectively, compared with sham (p < 0.05). Expression of necroptotic genes, namely, receptor-interacting protein kinases 1 and 3, and mixed lineage kinase domain-like in livers of burned mice were increased by 10-, 13-, and 4.5-fold, respectively, relative to sham (p < 0.05). Receptor-interacting protein kinase 1 and phosphorylated mixed lineage kinase domain-like protein levels measured by Western-blot in livers after burn injury were elevated by 22- and 17-fold, respectively, compared with sham (p < 0.05).

CONCLUSION

Liver damage occurs early after burns in mice and is associated with elevation of proinflammatory cytokines, chemokine, and proteins involved in the necroptotic pathway. This study suggests that necroptosis plays a role in the pathogenesis of liver failure secondary to burn injury.

MitoQ protects against liver injury induced by severe burn plus delayed resuscitation by suppressing the mtDNA-NLRP3 axis

INTRODUCTION

Liver injury induced by burn plus delayed resuscitation (B + DR) is life threatening in clinical settings. Mitochondrial damage and oxidative stress may account for the liver injury. MitoQ is a mitochondria-targeted antioxidant. We aimed to evaluate whether MitoQ protects against B + DR-induced liver injury.

METHODS

Rats were randomly divided into three groups: (1) the sham group; (2) the B + DR group, which was characterized by third-degree burn of 30% of the total body surface area plus delayed resuscitation, and (3) the treatment group, in which rats from the B + DR model received the target treatment. MitoQ was injected intraperitoneally (i.p) at 15 min before resuscitation and shortly after resuscitation. In the vitro experiments, Kupffer cells (KCs) were subjected to hypoxia/reoxygenation (H/R) injury to simulate the B + DR model. Mitochondrial characteristics, oxidative stress, liver function, KCs apoptosis and activation of the NLRP3 inflammasome in KCs were measured.

RESULTS

B + DR caused liver injury and oxidative stress. Excessive ROS lead to liver injury by damaging mitochondrial integrity and activating the mitochondrial DNA (mtDNA)-NLRP3 axis in KCs. The oxidized mtDNA, which was released into the cytosol during KCs apoptosis, directly bound and activated the NLRP3 inflammasome. MitoQ protected against liver injury by scavenging intracellular and mitochondrial ROS, preserving mitochondrial integrity and function, reducing KCs apoptosis, inhibiting the release of mtDNA, and suppressing the mtDNA-NLRP3 axis in KCs.

CONCLUSION

MitoQ protected against B + DR-induced liver injury by suppressing the mtDNA-NLRP3 axis.

Experimental models of scald burns. A scope review

Purpose:

To conduct a scope review of the experimental model described by Walker and Mason, by identifying and analyzing the details of the method.

Methods:

The authors searched Pubmed-Medline, Cochrane-Bireme and PEDro databases for articles published between January 2016 and December 2018, using the following search queries: burns, burn injuries, models animal, and animal experimentation. All articles whose authors used Walker and Mason's model - with or without changes to the method in Wistar rats - were included in this study.

Results:

The search identified 45 mentions of Walker and Mason's model; however, after reading each summary, 20 were excluded (of which 5 due to duplicity). The inconsistencies observed after the scope review were: water temperature, length of time of exposure of the experimental model's skin to water, extent of the burnt area, and the description of the thickness/depth of the injury.

Conclusions:

Reproducibility of a scientific method is the basis to prove the veracity of the observed results. Thus, it is necessary to have a greater number of publications that adopt a reproducible scientific method, for this review found inconsistencies in the description of Walker and Mason's model.

The effects of astaxanthin on liver histopathology and expression of superoxide dismutase in rat aflatoxicosis

The metabolism of aflatoxin B1 (AFB1) generates reactive oxygen species (ROS) that destroys hepatocytes. Meanwhile, astaxanthin (AX) is known to have stronger antioxidative activity than other carotenoids. This study aimed to investigate hepatoprotective role of AX from AFB1-induced toxicity in rat by histopathological study and immunohistochemistry of Cu/Zn-SOD (SOD1) which acts as the first enzyme in antioxidative reaction against cell injury from ROS. Twenty Wistar rats were randomly divided into 4 groups. The control and AFB1 groups were gavaged by water for 7 days followed by a single DMSO and 1 mg/kg AFB1, respectively. The AXL+ AFB1 and AXH+ AFB1 groups were given of 5 mg/kg and 100 mg/kg AX for 7 days before 1 mg/kg AFB1 administration. The result showed significantly elevated liver weight per 100 g body weight in AFB1 group. The histopathological finding revealed vacuolar degeneration, necrosis, megalocytosis and binucleation of hepatocytes with bile duct hyperplasia in AFB1 group. The severities of pathological changes were sequentially reduced in AXL+AFB1 and AXH+AFB1 groups. Most rats in AXH+AFB1 group owned hypertrophic hepatocytes and atypical proliferation of cholangiocytes which are adaptive responses to severe hepatocyte damage. The SOD1 expression was also significantly higher in AXH+AFB1 group than solely treated AFB1 and AXL+AFB1 groups. In conclusion, AX alleviated AFB1-induced liver damage in rat by stimulating SOD1 expression and transdifferentiation of cholangiocytes in dose dependent manner.

Short time insulin treatment post burn improves elastic-collagen rearrangement and reepithelization

Extensive burn may cause acute resistance to insulin, which accentuates hypermetabolism, impairs glucose metabolism, immune dysfunction and risks of sepsis. To minimize these effects, insulin is used as a treatment. The purpose was to analyze the collagen-elastic arrangement effects of insulin on the burned skin. Wistar rats were assigned in groups: control (C); control with insulin (C + I); scald burn injury (SBI); and SBI with insulin (SBI+ I). SBI were submitted to 45% total body surface area burn and the insulin-treated groups received insulin (5 UI/Kg/day) for 4 or 14 days (d). Insulin levels, glucose tolerance test and HOMA index were determined. The skin sections were analyzed for histophatological and morphoquantitative data. Histopathological findings showed increased reepithelization of SBI+ I and formation of a new muscle layer after 14 days. In the collagen-elastic arrangement, insulin for 4 days increased the volume fraction (Vv) of thin collagen and elastic fibers. After 14 days, independently of injury, insulin decreased the elastic fibers. Insulin was able to reverse damages in the collagen-elastic rearrangement and stimulate reepithelization after 4 days. Untreated scald-burned animals showed higher Vv of thick collagen after 4 days, while those treated had a higher Vv of thin collagen. The Vv of elastic fibers was increased in SBI+ I for 4 days. In conclusion, insulin treatment was able to stimulate reepithelization. It also reversed the damages to the collagen-elastic arrangement in the scald-burned group, improving the organization of thin collagen and increasing the Vv of elastic fibers in the injured group treated with insulin for a short time, that is, for 4 days.

Burn-Induced Multiple Organ Injury and Protective Effect of Lutein in Rats

Thermal injury may lead to multiple organ dysfunction through release of proinflammatory mediators and reactive oxygen radicals. This study investigated the effects of thermal injury on remote organs of rats and the possible protective effect of lutein. Thermal trauma was induced in the back of rats by exposing them to 90 °C bath for 10 s. Rats were sacrificed 48 h after burn, and blood samples were collected to monitor liver and kidney functions. Tissue samples from liver, kidneys, and lungs were taken for studying oxidative stress parameters, gene expressions of TNF-α and Casp-3, besides histopathological examination. Skin scald injury caused significant elevations of liver and kidney function biomarkers in the serum. In tissue samples, increments of MDA, GPx, and 8-OHdG were recorded while GSH level and the activities of CAT and SOD were suppressed. The expressions of TNF-α and caspase-3 mRNA were increased, and histopathological results revealed remote organ injury. Oral administration of lutein (250 mg/kg) resulted in amelioration of the biochemical and molecular changes induced by burn as well as the histopathological alterations. According to the findings of the present study, lutein possesses anti-oxidant, anti-inflammatory, and anti-apoptotic effects that protect against burn-induced damage in remote organs.