Epidemiological and Clinical Characteristics of 5,569 Pediatric Burns in Central China From 2013 to 2019.

Background: Pediatric burns of all the ages are prevalent worldwide, posing a severe health risk to children. This study aims to examine pediatric burns' clinical characteristics and epidemiology in central China. Methods: The pediatric patients of the Burn Research Center, Department of the First People's Hospital of Zhengzhou City from 2013 to 2019 were retrospectively studied and the relevant data were collected from the hospitalized medical records [e.g., demographic, etiology, length of stay (LOS), age, gender, burn area and depth, number of surgeries, cost, and outcome]. Results: A total of 5,569 pediatric burn patients were included, accounting for 43.9% of the total burn population. Electric burns represented a relatively small proportion (1.17%) but were more likely to lead to disabilities or death than scalds (90.63%) and flames (5.12%). The median age was 2 years [interquartile range (IQR): 1-4] and the boys/girls ratio ranged from 1.3:1 to 1.6:1. The most commonly burnt anatomic sites were the limbs (38.3%), with a median %TBSA (total body surface area) of 6 (IQR: 4-10). The complications of shock and pneumonia accounted for 7.6 and 19.2%, respectively. The peak months of pediatric burns included January, May, and August and the rural/urban ratio reached 1.61:1. The percentage of burn wounds treated surgically increased considerably from 2013 to 2019 (3.8 vs. 37.8%). The median hospital LOS was 15 days (IQR: 8-28 days), with the three high-risk factors (e.g., more surgeries, more %TBSA, full-thickness skin burns). The median cost of hospitalization was 1,511 USD (IQR: 848-2,648 USD) and the main risk factors consisted of full-thickness burns, more %TBSA, longer LOS, and more surgical procedures. Among all the patients, LA50 was 78.63% (95% CI = 75.12-83.45) and the overall mortality reached 0.1% since seven deaths were recorded. Conclusion: Scalds, flames, contact, and chemicals are the main causes of burns among children aged 1-5 years in central China. Accordingly, various prevention strategies should be employed depending upon the cause of the burn.

Topically administered rhGM-CSF affects PPARß expression in the stasis zone.

Using a rat comb thermal damage model, we investigated the effects of topically administered recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on peroxisome proliferator-activated receptor PPARß expression. We created bilateral comb scald models on the backs of fifty Sprague-Dawley rats. The left sides of the backs served as the experimental group and the right sides served as the control group. The experimental group received topically applied rhGM-CSF hydrogel and the control group did not. The survival situations of the stasis zones were compared between the experimental and control groups on the 1st, 3rd, 7th, 14th and 21st post-burn days. Tissues from the surviving stasis zones of both groups were collected at different time-points. Reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting were used to detect the PPARß mRNA and protein expression levels. Immunohistochemical methods were applied to detect the localization of PPARß protein expression. The results showed that, first, the tissue viability numbers for the stasis zones of the experimental group were significantly increased compared with those of the control group. Second, RT-PCR revealed that the PPARß mRNA expression first increased and then gradually declined in both groups. At all time-points, the expression level in the experimental group was increased compared with that in the control group and the highest expression levels were observed in both groups on the 3rd post-burn day. Third, western blot analysis revealed that the PPARß protein expression in both groups increased after thermal damage and then gradually decreased. PPARß protein expression in the experimental group was greater than that in the control group, and the highest expression quantities in both groups were observed on the 3rd post-burn day. In conclusion, rhGM-CSF hydrogel effectively promotes the expression of PPARß, and the hydrogel had a specific protective effect for the stasis zone.

[STUDY ON MODIFICATION OF BIOMATERIALS OF ACELLULAR BOVINE PERICARDIUM WITH DIFFERENT CROSSLINKING REAGENTS].

OBJECTIVE: To investigate the effects of modification of acellular bovine pericardium with 1-ethyl-3-(3- dinethylami-nopropyl) carbodimide (EDC)/N-hydroxysuccininide (NHS) or genipin and find out the best crosslinking reagent. METHODS: The cellular components of the bovine pericardiums were removed. The effects of decellularization were tested by HE staining. The acellular bovine pericardiums were crosslinked with EDC/NHS (EDC/NHS group) or genipin (genipin group). The properties of the crosslinked acellular matrix were evaluated by scanning electron microscope (SEM), matrix thickness, crosslinking index, mechanical property, denaturation temperature, enzymatic degradation, and cytotoxicity test before and after the crosslinking. Acellular bovine pericardium (ABP group) or normal bovine pericardium (control group) were harvested as controls. RESULTS: SEM showed that collagen fibers were reticulated in bovine pericardial tissues after crosslinked by EDC/NHS or genipin, and relative aperture of the collagen fiber was from 10 to 20 µm. The thickness and denaturation temperature of the scaffolds were increased significantly after crosslinking with EDC/NHS or genipin (P < 0.05), while there was no significant difference between EDC/NHS group and genipin group (P > 0.05). The difference had no statistical significance in crosslinking index between EDC/NHS group and genipin group (t = 0.205, P = 0.218). The degradation rate in EDC/NHS group and genipin group was significantly lower than that in ABP group and control group (P < 0.05). Elastic modulus and fracture stress in EDC/NHS group and genipin group were significantly lower than those in ABP group (P < 0.05), but there was no significant difference among EDC/NHS group, genipin group, and control group (P > 0.05). The break elongation in EDC/NHS group and genipin group were significantly increased than those in ABP group and control group (P < 0.05). The difference had no statistical significance in stability and mechanical properties between EDC/NHS group and genipin group (P > 0.05). Cytotoxicity of genipin crosslinked tissue (grade 1) were much lower than that of EDC/NHS (grade 2) at 5 days. CONCLUSION: Acellular bovine pericardium crosslinked with genipin has better biocompatibility than EDC/NHS.

[An experimental investigation of deep burn by constant low heat].

OBJECTIVE: To investigate the basic pathogenetic rule and mechanism of deep burn by constant low heat. METHODS: Animal burn model inflicted by constant low heat was established as follows. (1) The rats were randomly divided into groups in terms of temperature and duration of contact. The burn wound formation process, the skin tissue density and pathomorphological changes in the rats were observed after burn was produced on the back by contacting heat source constantly. (2) The subcutaneous temperature of the back was monitored at different time and temperatures of heat contacting by placing the thermometer under the fascia of the rat back. RESULTS: (1) The time of burn wound formation was shortened and the injury degree deepened along with the increase in the contact temperature. The rat skin density exhibited irregular hyperbola or triple curves. (2) The subcutaneous temperature exhibited a parabolic curve with fixed experimental conditions. CONCLUSION: (1) The sharp increase in subcutaneous temperature leading to degeneration and necrosis might be the primary cause of deep burn. (2) The regularity of the skin tissue injury was the result of multiple effects of heat-origin injury, increase of capillary permeability and the change in tissue mass.