Introduction: Histoplasmosis is a rare opportunistic, inhalation-acquired systemic mycosis caused by Histoplasma capsulatum, endemic to Southeast Asia, including Malaysia. Although classically seen in immunocompromised hosts, it is increasingly reported in immunocompetent individuals. Infection is associated with environmental exposures such as bat or bird droppings and soil disruption. Histoplasmosis is a progressive granulomatous disease that can closely mimic tuberculosis and malignancy, making diagnosis challenging. Case: An 87-year-old Malay male with a history of treated pulmonary tuberculosis presented with a 6-month history of intermittent fever, anorexia, weight loss, and hypotension. Initial computed tomography imaging demonstrated bilateral heterogeneous adrenal masses (right: 2.2 × 3.7 × 5.0 cm; left: 2.0 × 3.7 × 5.2 cm) with indeterminate washout characteristics. Biochemical adrenal evaluation, including a short Synacthen test, confirmed primary adrenal insufficiency. Extensive microbiological and malignancy workup, including bronchoscopy, cultures, and tumor markers, was non-diagnostic. In view of clinical deterioration and epidemiological risk, empirical antituberculous therapy was initiated; however, no clinical improvement was observed after 2 months. PET-FDG revealed intensely hypermetabolic bilateral adrenal masses (SUVmax right 16.7, left 13.2) with no other abnormal foci. Non-invasive fungal investigations were negative. Definitive diagnosis was established via computed tomography-guided adrenal biopsy, which demonstrated necrotizing granulomatous inflammation with intracellular yeasts, subsequently identified as H. capsulatum. The patient was treated with oral itraconazole and corticosteroid replacement, resulting in significant clinical improvement and planned interval radiological reassessment. Conclusion Disseminated histoplasmosis is a diagnostic challenge, particularly in frail elderly patients, where invasive procedures may be delayed. It can mimic tuberculosis and malignancy and may lack an identifiable exposure history. Non-invasive tests may be inconclusive, making tissue biopsy essential. Adrenal involvement may result in primary adrenal insufficiency, further complicating the clinical picture. Early consideration and timely confirmation are crucial for appropriate management.
Adrenal incidentaloma ; Lung Neoplasms

Introduction: Hashimoto's thyroiditis is a common autoimmune thyroid disease; however, pulmonary involvement is a rare manifestation. Lymphocytic interstitial pneumonitis is commonly associated with autoimmune diseases, but its association with Hashimoto's thyroiditis remains poorly understood. Case: A 63-year-old male with prior diagnosis of Hashimoto's thyroiditis presented with recurrent massive pleural effusion and progressive dyspnea. He also experienced fatigue, cold intolerance, and constipation. Physical examination revealed facial puffiness, diffuse goiter, and dry skin. Thyroid function tests performed 6 months before admission confirmed overt hypothyroidism (thyroidstimulating hormone [TSH] 80.30 µIU/mL, free thyroxine 4 [FT4] 0.46 ng/dL). One month prior to admission, laboratory findings showed subclinical hypothyroidism (TSH 9.09 µIU/mL, FT4 1.42 ng/dL). Despite levothyroxine treatment TSH levels remained elevated at 21.8 µIU/mL during admission. Anti-thyroid peroxidase antibodies were positive (13.95 IU/mL). Repeated thoracentesis revealed exudative pleural effusion with lymphocytic predominance and no evidence of malignancy in cytological examination. Infectious etiologies and malignancy were ruled out. Thyroid ultrasonography demonstrated diffuse hypoechoic enlargement of the thyroid gland. Chest radiography showed massive unilateral pleural effusion, while thoracic computed tomography revealed ground-glass opacities with a reticulogranular pattern and interlobular septal thickening, accompanied by multiple thin-walled cysts, highly suggestive of lymphocytic interstitial pneumonitis. Thyroid immunohistochemical analysis was performed (CD 20, CD 3, CD 10, CD 138, Ki 67, BCL 2, BCL 6, Thyroglobulin, MUM 1, Cyclin D1), consistent with lymphocytic thyroiditis. Significant clinical and laboratory improvement was achieved after combined treatment with levothyroxine and corticosteroid. Conclusion This case underscores the importance of considering autoimmune-related lymphocytic interstitial pneumonitis in patients with Hashimoto's thyroiditis who present with unexplained recurrent pleural effusion after exclusion of more common etiologies, such as infection and malignancy. Early recognition may lead to favorable improvement.
Lung Diseases, Interstitial ; Pleural Effusion ; Thyroiditis

BACKGROUND AND OBJECTIVES

Cell lines serve as invaluable tools in studying lung cancer biology and developing new therapies to combat the disease. However, commercially available cell lines are typically of Caucasian origin and may be less representative of the local genetic background. To address this, our lab previously immortalized cells from pleural fluid of a Filipino non-small cell lung cancer (NSCLC) patient via CDK4 transduction. Copy number variations (CNVs) are a type of genetic variation which may affect physiology and disease by disrupting gene function or altering gene expression, and in cancer, these may be associated with patient outcomes. CNV profiling can be valuable for understanding the biology of our immortalized cells and identifying genes that could serve as potential targets for diagnostic, prognostic, and therapeutic interventions. This study aimed to characterize previously immortalized NSCLC-derived cells, GL01, in comparison with an established lung adenocarcinoma (LUAD) cell line, A549, through whole-genome microarray-based copy number profiling.

DNA was extracted from GL01 and A549 cells using a commercially-available silica-based DNA extraction kit. DNA extracts were quantified and normalized for microarray analysis. Whole-genome copy number profiling was done using the OncoScan CNV Plus Assay following the manufacturer’s protocols, and data was analyzed using the Chromosome Analysis Suite software. Functional analysis of genes identified to be involved in copy number aberrations was done using the PANTHER Classification System.

Copy number aberrations span 1,592,737,105 bp in GL01 and 1,715,708,552 bp in A549, with a high degree of concordance between the two. Large-scale and focal copy number aberrations previously identified to be recurrent in various LUAD cohorts were present in both GL01 and A549. Focal copy number aberrations associated with previously described lung cancer-related genes involve the PDE4D gene in GL01 and the SKIL and CDKN2A/CDKN2B genes in both GL01 and A549. PANTHER Pathway analysis of genes positively correlated with mRNA expression showed that the ubiquitin proteasome pathway was significantly overrepresented in both GL01 (FDR p = 0.000074) and A549 (FDR p = 0.000075), with 20 genes involved. Additionally, the KRAS:p.G12C/S:c.34G>T/A somatic mutation variant was detected in both GL01 and A549.

This study provides a method for identifying potentially clinically-relevant genes associated with a sample’s copy number aberrations and the pathways they represent, providing personalized mechanistic, prognostic, and therapeutic insights into the cancer biology of our cells.

BACKGROUND

COVID-19 infection poses a continuing challenge especially to those already with prior lung disease. To analyze such patients’ profile is essential in today’s health care management.

The study aimed to compare the outcomes of COVID-19 confirmed patients with and without primary lung cancer in terms of hospital stay, recovery, and mortality.

The study employed a retrospective cohort design. Chart review of all adult COVID-19 patients in Philippine General Hospital from January 2021 to June 2021 was done. A matched cohort study was conducted between COVID-19 patients with and without primary lung cancer.

Among the 953 COVID-19 patients, there were 14 patients with primary lung cancer. In terms of length of hospital stay, patients with primary lung cancer had shorter days from 1.32 to 15.1 days compared to 2.28 to 18.36 days in patients without primary lung cancer (p-value 0.271). Furthermore, they had 64% recovery rate compared to 78% in those without primary lung cancer (p-value 0.118). In terms of overall mortality rate, primary lung cancer patients had 36% rate as compared to 22% in the non-lung cancer group (p-value 0.119). Diabetes mellitus, mild to severe COVID, Remdesivir, and antibiotic use were associated with longer hospital stay while oxygen support via nasal cannula and invasive ventilation led to shorter hospital stay. Age above 50 years, chronic liver disease, other malignancy, shortness of breath, oxygen support via face mask, high flow nasal cannula, invasive ventilation, antibiotic use, hemoperfusion and nebulization showed a decrease chance of recovery while on contrary, Remdesivir showed an increase chance of recovery. An increase mortality rate was seen among age above 50 years, chronic liver disease, other malignancy, shortness of breath, oxygen support via facemask, high flow nasal cannula, invasive ventilation, antibiotics, hemoperfusion, and nebulization, in contrast to a decrease in Remdesivir therapy.

Among all admitted COVID-19 patients, primary lung cancer patients were associated with shorter hospital stay (8.21+6.89days), lower rate of recovery (64%), and higher mortality rate (36%) as compared to those without primary lung cancer. However, based on the computed p-values for each outcome, these differences are not statistically significant.

OBJECTIVE: To explore the correlation between mechanical power normalized to dynamic lung compliance (Cdyn-MP) and weaning outcomes and prognosis in mechanically ventilated patients. METHODS: A prospective, observational cohort study was conducted. Patients who underwent invasive mechanical ventilation (IMV) for more than 24 hours and used a T-tube ventilation strategy for extubation in the intensive care unit (ICU) of Lianyungang First People's Hospital and Lianyungang Second People's Hospital between January 2022 and December 2023 were enrolled. The collected data encompassed patients' baseline characteristics, primary causes of ICU admission, vital signs and laboratory indicators during the initial spontaneous breathing trial (SBT), respiratory mechanics parameters within the 4-hour period prior to the SBT, weaning outcomes and prognostic indicators. Mechanical power (MP) and Cdyn-MP were calculated using a simplified MP equation. Univariate and multivariate Logistic regression analyses were utilized to determine the independent risk factors associated with weaning failure in patients undergoing mechanical ventilation. Restricted cubic spline (RCS) analysis and Spearman rank-sum test were employed to investigate the correlation between Cdyn-MP and weaning outcomes as well as prognosis. Receiver operator characteristic curve (ROC curve) was constructed, and the area under the ROC curve (AUC) was computed to evaluate the predictive accuracy of Cdyn-MP for weaning outcomes in mechanically ventilated patients. RESULTS: A total of 366 patients undergoing IMV were enrolled in this study, with 243 cases classified as successful weaning and 123 cases classified as failed weaning. Among them, 23 patients underwent re-intubation within 48 hours after the successful withdrawal of the first SBT, non-invasive ventilation, or died. Compared with the successful weaning group, the patients in the failed weaning group had significantly increased levels of sequential organ failure assessment (SOFA) score, body temperature and respiratory rate (RR) during SBT, and respiratory mechanical parameters within the 4-hour period prior to the SBT [ventilation frequency, positive end-expiratory pressure (PEEP), platform pressure (Pplat), peak inspiratory pressure (Ppeak), dynamic driving pressure (ΔPaw), fraction of inspired oxygen (FiO₂), MP, and Cdyn-MP], dynamic lung compliance (Cdyn) was significantly reduced, and duration of IMV, ICU length of stay, and total length of hospital stay were significantly prolonged. However, there were no statistically significant differences in age, gender, body mass index (BMI), smoking history, main causes of ICU admission, other vital signs [heart rate (HR), mean arterial pressure (MAP), saturation of peripheral oxygen (SpO₂)] and laboratory indicators [white blood cell count (WBC), albumin (Alb), serum creatinine (SCr)] during SBT of patients between the two groups. Univariate Logistic regression analysis was conducted, and variables with P < 0.05 and no multicollinearity with Cdyn-MP were selected for inclusion in the multivariate Logistic regression model. The results demonstrated that SOFA score [odds ratio (OR) = 1.081, 95% confidence interval (95%CI) was 1.008-1.160, P = 0.030], and PEEP (OR = 1.191, 95%CI was 1.075-1.329, P = 0.001), FiO₂ (OR = 1.035, 95%CI was 1.006-1.068, P = 0.021) and Cdyn-MP (OR = 1.190, 95%CI was 1.086-1.309, P < 0.001) within the 4-hour period prior to the SBT were independent risk factors for weaning failure in patients undergoing IMV. The RCS analysis after adjusting for confounding factors showed that as Cdyn-MP within the 4-hour period prior to the SBT increased, the risk of weaning failure in patients undergoing IMV significantly increased (P < 0.001). The Spearman rank correlation test showed that Cdyn-MP within the 4-hour period prior to the SBT was positively correlated with respiratory mechanical parameters including ΔPaw and MP (r values were 0.773 and 0.865, both P < 0.01), and negatively correlated with Cdyn (r = -0.587, P < 0.01). Cdyn-MP within the 4-hour period prior to the SBT was positively correlated with prognostic indicators such as duration of IMV, length of ICU stay, and total length of hospital stay (r values were 0.295, 0.196, and 0.120, all P < 0.05). ROC curve analysis demonstrated that, within the 4-hour period preceding the SBT, Cdyn-MP, MP, Cdyn, and ΔPaw possessed predictive value for weaning failure in patients undergoing IMV. Notably, Cdyn-MP exhibited superior predictive capability, evidenced by an AUC of 0.761, with a 95%CI ranging from 0.712 to 0.810 (P < 0.001). At the optimal cut-off value of 408.5 J/min×cmH₂O/mL×10^-3, the sensitivity was 68.29%, and the specificity was 71.19%. CONCLUSION Cdyn-MP is related to weaning outcomes and prognosis in mechanically ventilated patients, and has good predictive ability in assessing the risk of weaning failure.
Humans ; Prospective Studies ; Ventilator Weaning ; Prognosis ; Respiration, Artificial ; Intensive Care Units ; Lung Compliance ; Female ; Male ; Middle Aged ; Aged

Mechanical ventilation (MV) is currently widely used in the treatment of respiratory failure and anesthesia surgery, and is a commonly used respiratory support method for critically ill patients; however, improper usage of MV can lead to ventilator-induced lung injury (VILI), which poses a significant threat to patient life. Alveolar epithelial cell (AEC) has the functions of mechanosensation and mechanotransduction. Physiological mechanical stretching is beneficial for maintaining the lineage homeostasis and normal physiological functions of AEC cells, while excessive mechanical stretching can cause damage to AEC cells. Damage to AEC cells is an important aspect in the occurrence and development of VILI. Understanding the effects of mechanical stretching on AEC cells is crucial for developing safe and effective MV strategies, preventing the occurrence of VILI, and improving the clinical prognosis of VILI patients. From the perspective of cell mechanics, this paper aims to briefly elucidate the mechanical properties of AEC cells, mechanosensation and mechanotransduction of mechanical stretching in AEC cells, and the injury and repair of AEC cells under mechanical stretch stimulation, and potential mechanisms with the goal of helping clinical doctors better understand the pathophysiological mechanism of VILI caused by MV, improve their understanding of VILI, provide safer and more effective strategies for the use of clinical MV, and provide theoretical basis for the prevention and treatment of VILI.
Humans ; Mechanotransduction, Cellular ; Ventilator-Induced Lung Injury ; Stress, Mechanical ; Alveolar Epithelial Cells ; Respiration, Artificial/adverse effects* ; Epithelial Cells ; Pulmonary Alveoli/cytology* ; Animals

Mechanical ventilation is commonly employed for respiratory support in patients with respiratory failure. Despite the optimization of ventilator parameters and treatment methods, mechanical ventilation can still lead to both acute and chronic lung injury in patients with acute respiratory distress syndrome (ARDS) as well as in those without ARDS, a phenomenon referred to as ventilator-induced lung injury (VILI). VILI can be categorized into four types: barotrauma, volumetric injury, atelectasis injury, and biotic injury. Among these, biotic injury, characterized by inflammation, plays a significant role in the pathogenesis of VILI. Numerous studies have investigated the inflammatory mechanisms underlying VILI; however, these mechanisms remain complex and not entirely understood. At present, clinical practice lacks specific prevention and treatment strategies for VILI, aside from the implementation of protective ventilation strategies. Long non-coding RNAs (lncRNA) are a category of non-coding RNA longer than 200 nucleotides. LncRNAs regulate physiological and pathological processes such as cell proliferation, apoptosis, inflammatory response, and immune regulation, this regulation occurs through mechanisms such as modulating gene activity, inhibiting specific states, assisting in transcription initiation, affecting pre-mRNA splicing modifications, influencing translation processes, and expressing biofunctional peptides. They play an important role in the course of multiple diseases. Studies have shown that compared with control animals and cell models, lncRNAs are differentially expressed in VILI animal models and cell stretch models. Experiments have verified that certain lncRNAs play a crucial role in the pathogenesis of VILI by regulating the expression of inflammatory factors, the transformation of macrophage types, neutrophil activation, and cell apoptosis. Given the adverse effects of VILI on mechanical ventilation in critically ill patients, the important role of lncRNAs in biological regulation, and the urgent need to explore more effective strategies for the prevention and treatment of VILI, this paper summarizes the mechanisms through which lncRNA contributes to the VILI process, and discusses its possibility as a diagnostic and therapeutic target of VILI, in order to provide a reference for the clinical treatment of VILI.
RNA, Long Noncoding ; Ventilator-Induced Lung Injury ; Humans ; Respiration, Artificial/adverse effects* ; Animals ; Respiratory Distress Syndrome ; Apoptosis

Since the beginning of the 21st century, the severe respiratory infectious diseases worldwide [such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), influenza A H1N1 and novel coronavirus infection have attracted wide attention from all walks of life due to their superior pathogenicity and transmissibility. Aerosols-carrying pathogens are the main transmission route of many severe respiratory infectious diseases, which can lead to severe respiratory failure and even acute respiratory distress syndrome (ARDS) in infected individuals. Mechanical ventilation is the primary treatment for ARDS, and the small tidal volume, appropriate level of positive end-expiratory pressure based lung protective ventilation strategy can effectively reduce the incidence of ventilator-induced lung injury (VILI). However, in the process of clinical treatment, it is sometimes necessary to briefly disconnect the connection between the artificial airway and the ventilator circuit, which will not only cause the residual aerosol in the respiratory system to spill out and pollute the surrounding environment, increase the risk of nosocomial infection including medical staff, but also interfere with the implementation of lung protective ventilation strategy and aggravate ventilator-induced lung injury. In addition, studies have shown that a lot of medical staff have nosocomial infections, especially staff involved in tracheal intubation, extubation and other airway related operations. In addition to enhancing personal protective measures, it is crucial to safeguard healthcare workers from aerosol contamination and minimize associated risks during airway management. At present, there are few researches on the temporary sealing of airway lines and ventilator system, and there is a lack of clear guidance. This review summarizes the research status in related fields to provide a reference for corresponding solutions and programs.
Humans ; Respiratory Distress Syndrome/etiology* ; Respiration, Artificial ; Ventilator-Induced Lung Injury/prevention & control* ; Severe Acute Respiratory Syndrome ; COVID-19 ; Clinical Relevance

OBJECTIVE: To investigate whether the G protein-coupled estrogen receptor (GPER) can attenuates acute lung injury in mice with exertional heat stroke (EHS) by inhibiting ferroptosis. METHODS: Sixty SPF-grade male C57BL/6 mice were randomly divided into four groups: normal control group (control group), EHS model group (EHS group), dimethyl sulfoxide (DMSO) solvent group (EHS+DMSO group), and GPER-specific agonist G1 group (EHS+G1 group), with 15 mice in each group. All mice underwent 14 days of adaptive training at 24-26 centigrade before modeling, and the EHS model was established using a high-temperature treadmill device. After successful modeling, the mice were allowed to cool naturally at room temperature. In the EHS+G1 group, 40 μg/kg of the GPER-specific agonist G1 was slowly injected intraperitoneally immediately after modeling. In the EHS+DMSO group, 40 μg/kg of DMSO was slowly injected intraperitoneally immediately after modeling. The control group received no treatment. Five hours after modeling, abdominal aortic blood was collected, and lung tissues were harvested after euthanasia. The lung coefficient was calculated to evaluate lung injury. Lung histopathological changes were observed under a light microscope after hematoxylin-eosin (HE) staining, and a lung histopathological score was assigned. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), malondialdehyde (MDA), and Fe²⁺ in lung tissue. Immunofluorescence was used to detect the expression of glutathione peroxidase 4 (GPX4). Real-time polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of GPX4, ferroportin 1 (FPN1), and ferritin heavy chain 1 (FTH1). Western blotting was performed to detect the protein expression of GPX4, FPN1, and FTH1. RESULTS: Compared with the control group, the lung coefficient and lung histopathological score were significantly increased in the EHS group. HE staining showed significant thickening and unevenness of the alveolar septa and alveolar walls, partial alveolar collapse, and extensive erythrocyte, inflammatory cell, and plasma-like material extravasation in the alveolar spaces. Serum levels of TNF-α, IL-1β, MDA, and Fe²⁺ were significantly elevated. Immunofluorescence staining showed a significant decrease in GPX4-positive expression in lung tissue. Western blotting and RT-PCR showed significantly reduced protein and mRNA expression of GPX4, FPN1, and FTH1 in lung tissue. Compared with the EHS group, the EHS+G1 group showed a significant reduction in lung coefficient and lung histopathological score [lung coefficient (mg/g): 3.9±0.1 vs. 4.6±0.3, lung histopathological score: 4.2±0.2 vs. 6.9±0.2, both P < 0.05]. HE staining revealed reduced severity of lung tissue fluid extravasation, inflammatory infiltration, decreased hemorrhage, and less severe alveolar structural damage. Serum levels of TNF-α, IL-1β, MDA, and Fe²⁺ were significantly reduced [TNF-α (ng/L): 44.3±0.2 vs. 64.6±0.3, IL-1β (ng/L): 69.3±0.4 vs. 97.8±0.2, MDA (nmol/L): 2.8±0.3 vs. 3.6±0.5, Fe²⁺ (nmol/L): 0.021±0.004 vs. 0.028±0.004, all P < 0.05]. Immunofluorescence staining showed a significant decrease in GPX4-positive expression in lung tissue (fluorescence intensity: 35.53±2.41 vs. 16.45±0.31, P < 0.05). RT-PCR and Western blotting showed significantly increased mRNA and protein expression of GPX4, FPN1, and FTH1 in lung tissue [mRNA expression: GPX4 mRNA (2^-ΔΔCt): 0.44±0.05 vs. 0.09±0.01, FPN1 mRNA (2^-ΔΔCt): 0.77±0.17 vs. 0.42±0.14, FTH1 mRNA (2^-ΔΔCt): 0.75±0.04 vs. 0.58±0.01; protein expression: GPX4/β-actin: 0.96±0.11 vs. 0.24±0.04, FPN1/β-actin: 1.26±0.21 vs. 0.44±0.14, FTH1/β-actin: 0.27±0.12 vs. 0.15±0.07; all P < 0.05]. However, there were no statistically significant differences in any of the above indicators between the EHS+DMSO group and the EHS group. CONCLUSION Activation of GPER can attenuate EHS-related lung injury in mice, and its mechanism may be related to the activation of the GPX4 signaling pathway and inhibition of ferroptosis.
Animals ; Mice, Inbred C57BL ; Male ; Mice ; Heat Stroke/metabolism* ; Receptors, G-Protein-Coupled ; Ferroptosis ; Receptors, Estrogen ; Acute Lung Injury/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-1beta/metabolism* ; Lung Injury ; Lung/metabolism*

OBJECTIVE: To investigate the distribution characteristics of polymorphonuclear neutrophil (PMN) in the lungs during the early stage of severe burns and the mechanism of neutrophil elastase (NE) promoting lung injury. METHODS: 6-8-week-old male C57BL/6J mice were selected for the experiments. A 30% total body surface area (TBSA) III degree burn mouse model was established (severe burn group); the Sham-injury group was treated with 37 centigrade water. In the sodium sivelestat intervention group (SV intervention group), NE competitive inhibitor, sivelestat, 100 mg/kg, was injected via tail vein immediately after injury, while other groups received an equal volume of saline. Ten mice were harvested from each group to observe survival for 72 hours. Respiratory function tests were tested at 0 (immediate), 3, 6, 12, and 24 hours after molding. hematoxylin-eosin (HE) and immunohistochemical staining were used to observe lung tissue structure, inflammatory changes and PMN infiltration. The PMN absolute count in mice lung tissue was detected buy flow cytometry. At 6, 12, and 24 hours after molding, PMN counts and the concentration of NE [enzyme linked immunosorbent assay (ELISA)] in peripheral blood plasma, lung tissue, and bronchoalveolar lavage fluid (BALF) were detected. RESULTS: (1) HE staining results showed that compared with the Sham-injury group, the lungs of mice in the severe burn group showed inflammatory changes and PMN infiltration, with more significant changes at 6 hours. Immunohistochemistry results also confirmed that the expression of NE protein released from PMN significantly increased after 6 hours of severe burn injury [(3.79±0.62)% vs. (0.18±0.05)%, t = 11.56, P < 0.01]. (2) Compared with the Sham-injury group, the number of PMN and the concentration of NE in the peripheral blood and lung tissues in the severe burn group were significantly increased (F values were 13.709, 55.350 and 29.890, 13.286, respectively, all P < 0.01), peaking at 6 hours [plasma PMN count (×10⁹/L): 2.92±1.01 vs. 0.92±0.29, lung tissue PMN absolute count (cells): 48 788.03±11 833.91 vs. 1 516.72±415.35, plasma NE (ng/L): 24 522.71±3 842.92 vs. 7 009.34±4 067.86, lung tissue NE (ng/L): 262 189.04±9 695.13 vs. 65 026.03± 16 016.31, all P < 0.01]. The number of PMN in the lung of severely burned mice was highly correlated with NE concentration (r = 0.892, P < 0.001). There was no significantly difference in the PMN absolute count in the BALF of mice between the Sham-injury group and severe burn group (F = 1.403, P > 0.05). The Sham-injury group and severe burn group contained a small amount of NE in the BALF, and the concentration of NE in the BALF of the severely burned 6 hours and 12 hours groups were significantly higher than those of the Sham-injury group (ng/L: 328.58±158.10, 415.30±240.89 vs. 61.95±15.80, both P < 0.05). (3) Kaplan-Meier survival curve showed that the 72-hour survival rate of mice in the SV intervention group was significantly higher than that in the severe burn group (100% vs. 10%, Log-Rank test: χ² = 19.12, P < 0.001). (4) Compared with the Sham-injury group, all lung function indices of the severe burn group decreased significantly. All lung function indices of SV intervention group improved gradually over time, which were significantly better than those of the severe burn group. (5) Compared with the Sham-injury group, the PMN absolute count in lung tissue and the concentration of NE in plasma and lung tissue were significantly higher in the SV intervention group (F values were 46.709, 3.535, 32.701, respectively, all P < 0.05), with a peak at 6 hours. Compared with the severe burn group, the SV intervention group had a higher PMN absolute count in lung tissue (cells: 8 870.80±7 013.89 vs. 25 974.92±22 240.8, P < 0.05), and higher plasma and lung tissue NE concentrations (ng/L: 14 955.94±3 944.41 vs. 21 972.75±4 573.05, 81 956.87±38 658.35 vs. 168 182.30±83 513.91, both P < 0.01) were significantly decreased. CONCLUSIONS In the early stage of severe burns, there is a significant infiltration of PMN into the lungs. The NE promotes lung injury in the early stage of severe burn, and improve lung injury by inhibiting the action of NE.
Animals ; Burns/metabolism* ; Leukocyte Elastase/metabolism* ; Male ; Mice, Inbred C57BL ; Mice ; Neutrophils/metabolism* ; Lung/metabolism* ; Disease Models, Animal ; Neutrophil Infiltration ; Lung Injury/metabolism* ; Glycine/analogs & derivatives* ; Sulfonamides