Insignificant Difference in Early Post-injury Gene Expression Between Patients with Burns Only and Those with Inhalation Injury: A Bioinformatics Analysis.

Airway obstruction is fatal but common among burn patients in the early period after inhalation injury, during which most tracheotomies are performed within 48 h post-injury. Inflammation is common in laryngoscopy; however, the related gene expression has rarely been studied. In this study, we obtained the data of healthy control and patient samples collected within 8-48 hours post-injury from the Gene Expression Omnibus database and classified them into 10 inhalation-injury patients, 6 burn-only, and 10 healthy controls. Differential gene expression was identified between the patient groups; however, principal component analysis and cluster analysis indicated a similarity between groups. Furthermore, enrichment analysis, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analyses showed no significant differences in immune regulation and cell adjustment between the patient groups; but differences were shown when comparing either patient group to the healthy control group, including prominent regulation in inflammatory cells, infection, and cell adjustment. Thus, the gene expression in inhalation injury and burn-only patients does not significantly differ in the early period after injury, especially in inflammation, indicating the absence of specific diagnostic markers or anti-inflammatory treatment in inhalation injury patients, with the potential to identify more subtle differences. Further research is warranted.

Protection of laryngeal mucosa and function in laryngeal burns by heat absorption of perilaryngeal tissue.

OBJECTIVE: The laryngeal tissue carries most of the heat during inhalation injury. This study aims to explore the heat transfer process and the severity of injury inside laryngeal tissue by horizontally studying the temperature rise process at various anatomical layers of the larynx and observing the thermal damage in various parts of the upper respiratory tract. METHODS: The 12 healthy adult beagles were randomly divided into four groups, and inhaled room temperature air (control group), dry hot air of 80 °C (group I), 160 °C (group II), and 320 °C (group III) for 20 min, respectively. The temperature changes of the glottic mucosal surface, the inner surface of the thyroid cartilage, the external surface of the thyroid cartilage, and subcutaneous tissue were measured every minute. All animals were immediately sacrificed after injury, and pathological changes in various parts of laryngeal tissue were observed and evaluated under a microscope. RESULTS: After inhaling hot air of 80 °C, 160 °C and 320 °C, the increase of laryngeal temperature in each group was ΔT = 3.57 ± 0.25 °C, 7.83 ± 0.15 °C, 11.93 ± 0.21 °C. The tissue temperature was approximately uniformly distributed, and the difference was not statistically significant. The average laryngeal temperature-time curve showed that the laryngeal tissue temperature in group I and group II showed a trend of "first decrease and then increase", except that the temperature of group III directly increased with time. The prominent pathological changes after thermal burns mainly concluded necrosis of epithelial cells, loss of the mucosal layer, atrophy of submucosal glands, vasodilatation, erythrocytes exudation, and degeneration of chondrocytes. Mild degeneration of cartilage and muscle layers was also observed in mild thermal injury. Pathological scores indicated that the pathological severity of laryngeal burns increased significantly with the increase of temperature, and all layers of laryngeal tissue were seriously damaged by 320 °C hot air. CONCLUSIONS: The high efficiency of tissue heat conduction enabled the larynx to quickly transfer heat to the laryngeal periphery, and the heat-bearing capacity of perilaryngeal tissue has a certain degree of protective effect on laryngeal mucosa and function in mild to moderate inhalation injury. The laryngeal temperature distribution was in accordance with the pathological severity, and the pathological changes of laryngeal burns provided a theoretical basis for the early clinical manifestations and treatment of inhalation injury.

Directed reconstruction of a novel ancestral alcohol dehydrogenase featuring shifted pH-profile, enhanced thermostability and expanded substrate spectrum.

Ancestral enzymes are promising for industrial biotechnology due to high stability and catalytic promiscuity. An effective protocol was developed for the directed resurrection of ancestral enzymes. Employing genome mining with diaryl alcohol dehydrogenase KpADH as the probe, descendant enzymes D10 and D11 were firstly identified. Then through ancestral sequence reconstruction, A64 was resurrected with a specific activity of 4.3 U·mg-1. The optimum pH of A64 was 7.5, distinct from 5.5 of D10. The T15 50 and Tm values of A64 were 57.5 °C and 61.7 °C, significantly higher than those of the descendant counterpart. Substrate spectrum of A64 was quantitively characterized with a Shannon-Wiener index of 2.38, more expanded than D10, especially, towards bulky ketones in Group A and B. A64 also exhibited higher enantioselectivity. This study provides an effective protocol for constructing of ancestral enzymes and an efficient ancestral enzyme of industrial relevance for asymmetric synthesis of chiral alcohols.

Epidemiology and risk prediction of patients with severe burns admitted to a burn intensive care unit in a burn center in beijing: A 5-year retrospective study.

Objective: This study was performed to describe the epidemiology of patients with severe burns hospitalized in a burn intensive care unit (BICU), explore the risk factors associated with the patients' outcomes and evaluate the ability of prognostic scoring systems as risk prediction of mortality. Methods: The data for this study were derived from patients with severe burns in the BICU of Beijing Jishuitan Hospital from 2015 to 2019. The following epidemiological information and outcomes were collected for retrospective analysis: sex, age, date of injury, etiology of burn, admission time after injury, extent of burn, inhalation injury, length of stay, and outcome. Abbreviated Burn Severity Index (ABSI), prognostic burn index (PBI), the burn index (BI), Belgian Outcome in Burn Injury (BOBI) scores and the revised Baux (rBaux) scores were calculated. Results: Of the 243 patients included in this study, the median age was 41.00 (22.00) years and the male: female ratio was 4.28:1.00. Most of the burns had occurred from March to July. Flame was the main cause of the burns (77.37%), followed by electricity (14.40%). In total, 78.19% of all patients sustained third-degree burns, and the median burn area and third-degree burn area of patients were 40% (53%) and 15.0% (43.0%) of the total body surface area, respectively. The incidence of inhalation injury was 69.14%. Tracheotomy was performed in 53.89% of the patients with inhalation injuries, and the rate of tracheostomy showing a rising trend. The median length of stay was 37 (40) days, and the case fatality rate was 8.64%. Multivariable logistic regression model indicated that age and third-degree burn area were risk factors for death, and the area under the receiver operating characteristic curve for the full prediction model was 0.921 (95% CI = 0.874-0.967). Conclusions: The majority of severe burns are flame-related accidents in middle-aged men. Risk prediction model combining age and third-degree burn area has better mortality predictive value.

Kinetic Resolution of Nearly Symmetric 3-Cyclohexene-1-carboxylate Esters Using a Bacterial Carboxylesterase Identified by Genome Mining.

A new bacterial carboxylesterase (CarEst3) was identified by genome mining and found to efficiently hydrolyze racemic methyl 3-cyclohexene-1-carboxylate (rac-CHCM) with a nearly symmetric structure for the synthesis of (S)-CHCM. CarEst3 displayed a high substrate tolerance and a stable catalytic performance. The enantioselective hydrolysis of 4.0 M (560 g·L-1) rac-CHCM was accomplished, yielding (S)-CHCM with a >99% ee, a substrate to catalyst ratio of 1400 g·g-1, and a space-time yield of 538 g·L-1·d-1.

A novel carboxylesterase from Acinetobacter sp. JNU9335 for efficient biosynthesis of Edoxaban precursor with high substrate to catalyst ratio.

A novel carboxylesterase AcEst1 was identified from Acinetobacter sp. JNU9335 with high efficiency in the biosynthesis of chiral precursor of Edoxaban through kinetic resolution of methyl 3-cyclohexene-1-carboxylate (CHCM). Sequence analysis revealed AcEst1 belongs to family IV of esterolytic enzymes and exhibits <40% identities with known carboxylesterases. The optimum pH and temperature of recombinant AcEst1 are 8.0 and 40 °C. Substrate spectrum analysis indicated that AcEst1 prefers substrates with short acyl and alcohol groups. AcEst1 was highly active in the hydrolysis of CHCM with kcat of 1153 s-1 and displayed high substrate tolerance. As much as 2.0 M (280 g·L-1) CHCM could be enantioselectively hydrolyzed into (S)-CHCM by merely 0.08 g·L-1AcEst1 with ees of >99% (S) and substrate to catalyst ratio (S/C) of 3500 g·g-1. These results indicate that the novel AcEst1 is a promising biocatalyst in the synthesis of chiral carboxylic acids.

Efficient microbial resolution of racemic methyl 3-cyclohexene-1-carboxylate as chiral precursor of Edoxaban by newly identified Acinetobacter sp. JNU9335.

Optically active 3-cyclohexene-1-carboxylic acid (CHCA) derivatives are important pharmaceutical intermediates. Due to the special rotatable structure, enantioselective preparation of chiral CHCA is hard to achieve. To identify efficient and enantioselective hydrolases for the biosynthesis of CHCA from methyl 3-cyclohexene-1-carboxylate (CHCM), target-oriented screening from soil samples and gene mining from genome database were explored. All putative hydrolases attempted displayed low enantioselectivity. A hydrolase-producing strain JNU9335 was successfully identified with relatively high enantioselectivity, and was designated as a strain of Acinetobacter sp. according to 16S rDNA sequence and phylogenetic analysis. After optimization, strain JNU9335 could produce 233 U·L‒1 hydrolase with E value of 21. Isooctane/aqueous biphasic system is favorable for the enzymatic resolution of CHCM, the E value of JNU9335 could further be increased to 36. The newly identified JNU9335 could tolerate as high as 1.0 M CHCM, producing (S)-CHCM with ees of 99.6% and isolation yield of 34.7%. This study provides an efficient biocatalyst for the preparation of chiral 3-cyclohexene-1-carboxylic acid derivatives.

Ghrelin accelerates the cartilagic differentiation of rabbit mesenchymal stem cells through the ERK1/2 pathway.

Mesenchymal stem cells (MSCs) can differentiate into chondroblasts, adipocytes, or cartilage under appropriate stimulation. Identifying a mechanism triggering the differentiation of MSCs into cartilage may help develop novel therapeutic approaches for treating heterotopic ossification, the pathological formation of lamellar bone in soft tissue outside the skeleton that can lead to debilitating immobility. Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, stimulates growth hormone secretion, and has both orexigenic and adipogenic effects. This study sought to understand the potential involvement of the ERK1/2 signaling pathway in the ghrelin-induced growth of rat MSCs (rMSCs). We applied various concentrations of ghrelin to cultured rMSCs by observing the changes in the phosphorylation state of ERK1/2, p38, JNK as well as the type II collagen expression levels by western blot. The highest expression level for both type II collagen was obtained with 600 ng/mL ghrelin at 24 h. We found that the ghrelin-induced differentiation of rMSCs into cartilage was promoted primarily by the ERK1/2 pathway. Our study suggests that ghrelin induced differentiation of rMSCs into cartilage primarily through the ERK1/2 pathway.

Pooling-analysis for diagnostic and prognostic value of MiRNA-100 in various cancers.

Many studies manifested miRNA-100 was deregulated in various cancers, which indicated that miRNA-100 might be a potential biomarker of cancer diagnosis and prognosis. However, the role of miRNA-100 was still uncertain. We searched for qualified studies using PubMed, EMBASE, Web of Science, Cochrane library and CNKI databases. The diagnostic effect was evaluated by the pooled sensitivity, specificity, and other indexes. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) were calculated to assess the prognostic value. This meta-analysis included 7 and 19 studies about diagnosis and prognosis, respectively. The results of pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) were 0.75 (95%CI: 0.71-0.78), 0.74 (95%CI: 0.69-0.78), 2.61 (95%CI: 1.81-3.76), 0.33 (95%CI: 0.24-0.45), 8.46 (95%CI: 4.85-14.77), respectively. And, the area under SROC curve (AUC) was 0.8141. We also found that lower expression of miRNA-100 in cancer tissues could significantly predict poorer prognosis in overall cancer (HR = 0.59, 95%CI: 0.39-0.90), especially in genital system tumors (HR = 0.42, 95%CI: 0.27-0.66, P = 0.431), bladder cancer (HR = 0.21, 95%CI: 0.06-0.73, P = 0.143) and esophageal squamous cell carcinoma (HR = 0.26, 95%CI: 0.13-0.52, P = 0.164). Our studies concluded that miRNA-100 has a certain value in diagnosis and it may indicate a poor prognosis of cancers.