Curbing inflammation in burn patients

Methanol Extract from Anogeissus leiocarpus (DC) Guill. et Perr. (Combretaceae) Stem Bark Quenches the Quorum Sensing of Pseudomonas aeruginosa PAO1

Background: Due to its extensive arsenal of virulence factors and inherent resistance to antibiotics, Pseudomonas aeruginosa is a threat particularly in immunocompromised patients. Considering the central role of quorum sensing in the production of virulence factors, inhibition of bacterial communication mechanism constitute an opportunity to attenuate pathogenicity of bacteria resistant to available antibiotics. Our study aimed to assess the anti-quorum sensing activity of Anogeissus leiocarpus, traditionally used in Burkina Faso, for the treatment of infected burn wounds. Methods: Investigations were carried out on methanol extract from A. leiocarpus stem bark. The reporter strains Chromobacterium violaceum CV026 and P. aeruginosa PAO1 derivatives were used to evidence any interference with the bacterial quorum sensing and expression of related genes. P. aeruginosa PAO1 was used to measure the impact on pyocyanin production. Results: At a sub-inhibitory concentration (100 µg/mL), A. leiocarpus methanol extract quenched the quorum sensing mechanism of P. aeruginosa PAO1 by down-streaming the rhlR gene, with a subsequent reduction of pyocyanin production. Moreover, the antioxidant polyphenols evidenced are able to reduce the oxidative stress induced by pyocyanin. Conclusion: The antioxidant and anti-quorum sensing activities of A. leiocarpus stem bark could justify its traditional use in the treatment of infected burn wounds.

TNF-α/IL-10 Ratio Correlates with Burn Severity and May Serve as a Risk Predictor of Increased Susceptibility to Infections

Severe burn injury renders patients susceptible to multiple infection episodes; however, identifying specific patient groups at high risk remains challenging. Burn-induced inflammatory response dramatically modifies the levels of various cytokines. Whether these changes could predict susceptibility to infections remains unknown. The aim of this study was to determine the early changes in the pro- to anti-inflammatory cytokine ratio and investigate its ability to predict susceptibility to repeated infections after severe burn trauma. The patient population consisted of 34 adult patients having early (≤48 h since injury) blood draws following severe (≥20% total burn surface area (TBSA)) burn injury and suffering from a first infection episode at least 1 day after blood collection. Plasma TNF-α and IL-10 levels were measured to explore the association between the TNF-α/IL-10 ratio, hypersusceptibility to infections, burn size (TBSA), and common severity scores (Acute Physiology and Chronic Health Evaluation II (APACHEII), Baux, modified Baux (R-Baux), Ryan Score, and Abbreviated Burn Severity Index (ABSI)). TNF-α/IL10 plasma ratio measured shortly after burn trauma was inversely correlated with burn size and the injury severity scores investigated, and was predictive of repeated infections (≥3 infection episodes) outcome (AUROC [95%CI] of 0.80 [0.63-0.93]). Early measures of circulating TNF-α/IL10 ratio may be a previously unidentified biomarker associated with burn injury severity and predictive of the risk of hypersusceptibility to repeated infections.

Fumarate-loaded electrospun nanofibers with anti-inflammatory activity for fast recovery of mild skin burns

In the biomedical sector the availability of engineered scaffolds and dressings that control and reduce inflammatory states is highly desired, particularly for the management of burn wounds. In this work, we demonstrate for the first time, to the best of our knowledge, that electrospun fibrous dressings of poly(octyl cyanoacrylate) (POCA) combined with polypropylene fumarate (PPF) possess anti-inflammatory activity and promote the fast and effective healing of mild skin burns in an animal model. The fibers produced had an average diameter of (0.8  ±  0.1) µm and they were able to provide a conformal coverage of the injured tissue. The application of the fibrous mats on the burned tissue effectively reduced around 80% of the levels of pro-inflammatory cytokines in the first 48 h in comparison with un-treated animals, and enhanced skin epithelialization. From histological analysis, the skin thickness of the animals treated with POCA : PPF dressings appeared similar to that of one of the naïve animals: (13.7  ±  1.4) µm and (14.3  ±  2.5) µm for naïve and treated animals, respectively. The density of dermal cells was comparable as well: (1100  ±  112) cells mm(-2) and (1358  ±  255) cells mm(-2) for naïve and treated mice, respectively. The results demonstrate the suitability of the electrospun dressings in accelerating and effectively promoting the burn healing process.

The Use of Redox Expression and Associated Molecular Damage to Evaluate the Inflammatory Response in Critically Ill Patient with Severe Burn

The patient with severe burns always represents a challenge for the trauma team due to the severe biochemical and physiopathological disorders. Although there are many resuscitation protocols of severe burn patient, systemic inflammatory response, oxidative stress, decreased immune response, infections, and multiple organ dysfunction syndromes are still secondary complications of trauma, present at maximum intensity in this type of patients. Currently there are numerous studies regarding the evaluation, monitoring, and minimizing the side effects induced by free radicals through antioxidant therapy. In this study, we want to introduce biochemical and physiological aspects of oxidative stress in patients with severe burns and to summarize the biomarkers used presently in the intensive care units. Systemic inflammations and infections are according to the literature the most important causes of death in these type of patients, being directly involved in multiple organ dysfunction syndrome and death.

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

AIM: To investigate effects of severe burn injury (BI) in rat liver through the histopathological and inflammatory markers analysis.

METHODS: Forty-two male Wistar rats were distributed into two groups, control (C) and subjected to scald BI (SBI). The animals were euthanized one, four and 14 d post sham or 45% of the total body surface BI. Liver fragments were submitted to histopathological, morphoquantitative (hepatocyte area and cell density), ciclooxigenase-2 (COX-2) immunoexpression, and gene expression [real-time polymerase chain reaction for tumor necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS) and caspase-3] methods.

RESULTS: Histopathological findings showed inflammatory process in all periods investigated and hepatocyte degeneration added to increased amount of connective tissue 14 d post injury. Hepatocyte area, the density of binucleated hepatocytes and density of sinusoidal cells of SBI groups were increased when compared with control. COX-2 immunoexpression was stronger in SBI groups. No differences were found in TNF-α, iNOS and caspase-3 gene expression.

CONCLUSION: BI induces histopathological changes, upregulation of COX-2 immunoexpression, and cell proliferation in liver of rats.

Burn wound healing and treatment: review and advancements

Burns are a prevalent and burdensome critical care problem. The priorities of specialized facilities focus on stabilizing the patient, preventing infection, and optimizing functional recovery. Research on burns has generated sustained interest over the past few decades, and several important advancements have resulted in more effective patient stabilization and decreased mortality, especially among young patients and those with burns of intermediate extent. However, for the intensivist, challenges often exist that complicate patient support and stabilization. Furthermore, burn wounds are complex and can present unique difficulties that require late intervention or life-long rehabilitation. In addition to improvements in patient stabilization and care, research in burn wound care has yielded advancements that will continue to improve functional recovery. This article reviews recent advancements in the care of burn patients with a focus on the pathophysiology and treatment of burn wounds.

Comparison of systemic inflammation response and vital organ damage induced by severe burns in different area

BACKGROUND

In this study, we will establish a stable and optimized rat model that can meet strictly diagnosed criteria and serve as a tool to investigate the potential of novel therapeutics in this preclinical model through comparative analysis of systemic alterations, levels of pro-inflammatory cytokines in serum and infiltrated numbers of inflammatory cells in distant organ between 30% and 50% TBSA with a full-thickness burn.

MATERIALS AND METHODS

The adult male Wistar rats were randomly divided into the following groups: control group, 30% TBSA with a full-thickness burn group, and 50% TBSA with a full-thickness burn group. The blood and serum samples in the 3 groups were collected and detected by blood routine examination and biochemical detection at 6 h, 12 h, 24 h and 48 h post burn. The levels of TNF-α, IL-1β and IL-6 in serum were detected by ELISA. The sections of lung, renal, liver and heart were analyzed by H&E and immunohistochemical staining detection.

RESULTS

Our results showed that temperature in 50% TBSA with a full-thickness burn group was always hypothermia, and lower than 36°C at defined timepoints post burn, that was in 30% TBSA with a full-thickness burn group was lower than 36°C only at 48 h post burn. The levels of TNF-α, IL-1β and IL-6 were significantly increased in 30% and 50% groups at 6 h, 12 h, 24 h and 48 h post burn. The apoptosis in distant organs and the biochemical parameters such as ALT, AST, troponin, CK, CK-MB, LDH, urea and creatinine in 30% and 50% groups were also increased at different degrees at defined timepoints after burn, but changes in 50% group were more obvious than that in 30% group.

CONCLUSION

We choose 50% TBSA with a full-thickness burn to establish a stable and optimized rat model that can meet strictly diagnosed criteria and serve as a tool to investigate the potential of novel therapeutics in this preclinical model.

Xenogeneic Mesenchymal Stromal Cells Improve Wound Healing and Modulate the Immune Response in an Extensive Burn Model

Major skin burns are difficult to treat. Patients often require special care and long-term hospitalization. Besides specific complications associated with the wounds themselves, there may be impairment of the immune system and of other organs. Mesenchymal stromal cells (MSCs) are a recent therapeutic alternative to treat burns, mainly aiming to accelerate the healing process. Several MSC properties favor their use as therapeutic approach, as they promote angiogenesis, stimulate regeneration, and enhance the immunoregulatory function. Moreover, since patients with extensive burns require urgent treatment and because the expansion of autologous MSCs is a time-consuming process, in this present study we chose to evaluate the therapeutic potential of xenogeneic MSCs in the treatment of severe burns in rats. MSCs were isolated from mouse bone marrow, expanded in vitro, and intradermally injected in the periphery of burn wounds. MSC-treated rats presented higher survival rates (76.19%) than control animals treated with PBS (60.86%, p < 0.05). In addition, 60 days after the thermal injury, the MSC-treated group showed larger proportion of healed areas within the burn wounds (90.81 ± 5.05%) than the PBS-treated group (76.11 ± 3.46%, p = 0.03). We also observed that CD4(+) and CD8(+) T cells in spleens and in damaged skin, as well as the percentage of neutrophils in the burned area, were modulated by MSC treatment. Plasma cytokine (TGF-β, IL-10, IL-6, and CINC-1) levels were also altered in the MSC-treated rats, when compared to controls. Number of injected GFP(+) MSCs progressively decreased over time, and 60 days after injection, few MSCs were still detected in the skin of treated animals. This study demonstrates the therapeutic effectiveness of intradermal application of MSCs in a rat model of deep burns, providing basis for future regenerative therapies in patients suffering from deep burn injuries.

Temporal study following burn injury in young rats is associated with skeletal muscle atrophy, inflammation and altered myogenic regulatory factors

INTRODUCTION

Burn injury (BI) greater than 40% has been associated with protein catabolism and it is characterized by a hypermetabolic response followed for muscle loss.

OBJECTIVE

The purpose of this study was to investigate the temporal effects of extensive experimental BI in the skeletal muscle distant from lesion, through morphological analysis, expression of genes related to muscle atrophy, inflammation and the myogenic regulatory factors.

MATERIALS AND METHODS

A total of 60 young male wistar rats were distributed into two groups, control (C) and subjected to scald burn injury (SBI). The animals were euthanized 1, 4 and 14 days post-sham or 45% of the total body surface BI. The medial head of gastrocnemii muscles were submitted to histopathological, morphometric (muscle fibers area and density), MyoD and myogenin immunoexpression, and gene expression for TNF-α, iNOS and E3 ubiquitin ligases (MuRF1 and MAFbx).

RESULTS

Histopathological findings were consistent with increased amount of connective tissue and inflammatory process. Muscle fiber area of SBI groups was smaller than C and no differences were found in fiber muscle density. TNF-α was higher in SBI groups, one and 14 days post-injury; iNOS expression was higher on the first and fourth day post-injury. MuRF-1 was higher on the day four and MAFbx on the day 14.

CONCLUSION

In conclusion, BI causes inflammation, atrophy and myogenesis stimulation in muscle as a result of systemic host response.