Upregulation of PGC-1α expression by pioglitazone mediates prevention of sepsis-induced acute lung injury

Abstract The imbalance between pro-inflammatory M1 and anti-inflammatory M2 macrophages plays a critical role in the pathogenesis of sepsis-induced acute lung injury (ALI). Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may modulate macrophage polarization toward the M2 phenotype by altering mitochondrial activity. This study aimed to investigate the role of the PGC-1α agonist pioglitazone (PGZ) in modulating sepsis-induced ALI. A mouse model of sepsis-induced ALI was established using cecal ligation and puncture (CLP). An in vitro model was created by stimulating MH-S cells with lipopolysaccharide (LPS). qRT-PCR was used to measure mRNA levels of M1 markers iNOS and MHC-II and M2 markers Arg1 and CD206 to evaluate macrophage polarization. Western blotting detected expression of peroxisome proliferator-activated receptor gamma (PPARγ) PGC-1α, and mitochondrial biogenesis proteins NRF1, NRF2, and mtTFA. To assess mitochondrial content and function, reactive oxygen species levels were detected by dihydroethidium staining, and mitochondrial DNA copy number was measured by qRT-PCR. In the CLP-induced ALI mouse model, lung tissues exhibited reduced PGC-1α expression. PGZ treatment rescued PGC-1α expression and alleviated lung injury, as evidenced by decreased lung wet-to-dry weight ratio, pro-inflammatory cytokine secretion (tumor necrosis factor-α, interleukin-1β, interleukin-6), and enhanced M2 macrophage polarization. Mechanistic investigations revealed that PGZ activated the PPARγ/PGC-1α/mitochondrial protection pathway to prevent sepsis-induced ALI by inhibiting M1 macrophage polarization. These results may provide new insights and evidence for developing PGZ as a potential ALI therapy.

Edema pulmonar por reexpansión. Reporte de Caso / Pulmonary edema due to re-expansion. Case Report

Introducción. El edema pulmonar por reexpansión es una complicación poco frecuente, secundaria a una rápida reexpansión pulmonar posterior al drenaje por toracentesis o toracostomía cerrada. Al día de hoy, se ha descrito una incidencia menor al 1 % tras toracostomía cerrada, con mayor prevalencia en la segunda y tercera década de la vida. Su mecanismo fisiopatológico exacto es desconocido; se ha planteado un proceso multifactorial de daño intersticial pulmonar asociado con un desequilibrio de las fuerzas hidrostáticas. Caso clínico. Presentamos el caso de un paciente que desarrolló edema pulmonar por reexpansión posterior a toracostomía cerrada. Se hizo una revisión de la literatura sobre esta complicación. Resultados. Aunque la clínica sugiere el diagnóstico, la secuencia de imágenes desempeña un papel fundamental. En la mayoría de los casos suele ser autolimitado, por lo que su manejo es principalmente de soporte; sin embargo, se han reportado tasas de mortalidad que alcanzan hasta el 20 %, por tanto, es importante conocer los factores de riesgo y las medidas preventivas. Conclusión. El edema pulmonar de reexpansión posterior a toracostomía es una complicación rara en los casos con neumotórax, aunque es una complicación que se puede presentar en la práctica diaria, por lo cual debe tenerse en mente para poder hacer el diagnóstico y un manejo adecuado.

Introduction. Re-expansion pulmonary edema is a rare complication secondary to rapid pulmonary re-expansion after drainage by thoracentesis and/or closed thoracostomy. As of today, an incidence of less than 1% has been described after closed thoracostomy, with a higher prevalence in the second and third decades of life. Its exact pathophysiological mechanism is unknown; a multifactorial process of lung interstitial damage associated with an imbalance of hydrostatic forces has been proposed. Clinical case. We present the case of a patient who developed pulmonary edema due to re-expansion after closed thoracostomy, conducting a review of the literature on this complication. Results. Although the clinic suggests the diagnosis, the sequence of images plays a fundamental role. In most cases, it tends to be a self-limited disease, so its management is mainly supportive. However, mortality rates of up to 20% have been recorded. Therefore, it is important to identify patients with major risk factors and initiate preventive measures in these patients. Conclusions. Re-expansion pulmonary edema after thoracostomy is a rare complication in cases with pneumothorax; however, it is a complication that can occur in daily practice. Therefore, it must be kept in mind to be able to make the diagnosis and an adequate management.

Respiratory system parameters in children with low severity cystic fibrosis: is there early involvement in relation to healthy peers? / Parâmetros do sistema respiratório em crianças com fibrose cística de baixa gravidade: há acometimento precoce em relação a pares saudáveis?

ABSTRACT Objective: To compare and analyze pulmonary function and respiratory mechanics parameters between healthy children and children with cystic fibrosis. Methods: This cross-sectional analytical study included healthy children (HSG) and children with cystic fibrosis (CFG), aged 6-13 years, from teaching institutions and a reference center for cystic fibrosis in Florianópolis/SC, Brazil. The patients were paired by age and sex. Initially, an anthropometric evaluation was undertaken to pair the sample characteristics in both groups; the medical records of CFG were consulted for bacterial colonization, genotype, and disease severity (Schwachman-Doershuk Score — SDS) data. Spirometry and impulse oscillometry were used to assess pulmonary function. Results: In total, 110 children were included, 55 in each group. In the CFG group, 58.2% were classified as excellent by SDS, 49.1% showed the ΔF508 heterozygotic genotype, and 67.3% were colonized by some pathogens. Statistical analysis revealed significant differences between both groups (p<0.05) in most pulmonary function parameters and respiratory mechanics. Conclusions: Children with cystic fibrosis showed obstructive ventilatory disorders and compromised peripheral airways compared with healthy children. These findings reinforce the early changes in pulmonary function and mechanics associated with this disease.

RESUMO Objetivo: Comparar e analisar parâmetros de função pulmonar e de mecânica respiratória entre escolares saudáveis e com fibrose cística (FC). Métodos: Estudo transversal que incluiu escolares saudáveis (GES) e com FC (GFC), com idades entre seis e 13 anos, provenientes de instituições de ensino e de um centro de referência da FC em Florianópolis/SC, Brasil, pareados por idade e sexo, respectivamente. Inicialmente, conduziu-se avaliação antropométrica para pareamento e caracterização de ambos os grupos e, no GFC, consultou-se prontuário médico para registro dos dados de colonização bacteriana, genótipo e gravidade da doença (Escore de Schwachman-Doershuk — ESD). Para a avaliação da função pulmonar, realizou-se espirometria e a avaliação da mecânica respiratória foi conduzida por meio do sistema de oscilometria de impulso. Resultados: Participaram 110 escolares, 55 em cada grupo. No GFC, 58,2% foram classificados pelo ESD como excelentes, 49,1% apresentaram genótipo ∆F508 heterozigoto e 67,3% eram colonizados por alguma patógeno. Houve diferença significativa (p<0,05) na maioria dos parâmetros de função pulmonar e de mecânica respiratória entre os grupos. Conclusões: Escolares com FC apresentaram distúrbio ventilatório obstrutivo e com comprometimento de vias aéreas periféricas, em comparação aos escolares hígidos. Esse evento reforça o início precoce da alteração de função pulmonar e de mecânica respiratória nessa enfermidade, evidenciados pelos achados desta investigação.

Xuebijing improves inflammation and pyroptosis of acute lung injury by up-regulating miR-181d-5p-mediated SPP1 inactivation

Abstract Background Xuebijing (XBJ) is widely applied in the treatment of Acute Lung Injury (ALI). This study focused on the potential mechanism of XBJ in Lipopolysaccharide (LPS)-induced ALI. Methods The rat ALI model was established by injection of LPS (10 mg/kg) and pretreated with XBJ (4 mL/kg) three days before LPS injection. BEAS-2B cell line was stimulated with LPS (1 μg/mL) and ATP (5 mM) to induce pyroptosis, and XBJ (2 g/L) was pretreated 24h before induction. The improvement effects of XBJ on pulmonary edema, morphological changes, and apoptosis in ALI lung tissue were evaluated by lung wet/dry weight ratio, HE-staining, and TUNEL staining. Inflammatory cytokines in lung tissue and cell supernatant were determined by ELISA. pyroptosis was detected by flow cytometry. Meanwhile, the expressions of miR-181d-5p, SPP1, p-p65, NLRP3, ASC, caspase-1, p20, and GSDMD-N in tissues and cells were assessed by RT-qPCR and immunoblotting. The relationship between miR-181d-5p and SPP1 in experimental inflammation was reported by dual luciferase assay. Results XBJ could improve inflammation and pyroptosis of ALI by inhibiting contents of inflammatory cytokines, and levels of inflammation- and pyroptosis-related proteins. Mechanistically, XBJ could up-regulate miR-181d-5p and inhibit SPP1 in ALI. miR-181d-5p can target the regulation of SPP1. Depressing miR-181d-5p compensated for the ameliorative effect of XBJ on ALI, and overexpressing SPP1 suppressed the attenuating effect of XBJ on LPS-induced inflammation and pyroptosis. Conclusion XBJ can regulate the miR-181d-5p/SPP1 axis to improve inflammatory response and pyroptosis in ALI.

Protective Effect of Zingiberis Rhizoma Recens on LPS-induced Acute Lung Injury in Mice Through TLR4/NF-κB Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the protective effect and mechanism of Zingiberis Rhizoma Recens alcohol extract on lipopolysaccharide （LPS）-induced acute lung injury in mice. MethodBalb/c mice were randomly divided into normal group， model group， dexamethasone group， and low- and high-dose Zingiberis Rhizoma Recens groups. Mice in the normal group were instilled with normal saline through the nose， and the other groups were instilled with normal saline containing LPS （50 μg）. After 30 minutes of modeling， the dexamethasone group was gavaged with 5 mg·kg-1 of dexamethasone acetate solution， the low- and high-dose Zingiberis Rhizoma Recens groups were gavaged with different doses of （7， 14 g·kg-1） of Zingiberis Rhizoma Recens alcohol extract， and the normal group and the model group were gavaged with the same volume of water. After 24 hours of modeling， the total number of white blood cells in bronchoalceolar lavage fluid （BALF） was detected by cell counter， and the levels of the inflammatory factors including tumor necrosis factor （TNF）-α， interleukin （IL）-1β， IL-6， and superoxide dismutase （SOD）， and myeloperoxidase （MPO） was detected by enzyme-linked immunosorbent assay （ELISA）. Haematoxylin-eosin （HE） staining method was used to observe the pathological changes of lung tissue in each group， and the Western blot was used to detect the protein expression of nuclear transcription factor （NF）-κB p65， phosphorylation （p）-NF-κB p65， and Toll-like receptor 4 （TLR4） in lung tissue. ResultCompared with the normal group， the white blood cell count in BALF and the levels of TNF-α， IL-1β， IL-6， and MPO in the model group was increased （P<0.01）， and the level of SOD was decreased （P<0.05）. Pathological damage of lung tissue was obvious， and the protein expression of NF-κB p65， p-NF-κB p65， and TLR4 in lung tissue was increased （P<0.01）. Compared with the model group， the white blood cell count in BALF and the levels of TNF-α， IL-1β， IL-6， and MPO in the treatment group was decreased （P<0.05，P<0.01）， and the level of SOD was increased （P<0.05，P<0.01）. Pathological damage of lung tissue was alleviated， and the protein expression of NF-κB p65， p-NF-κB p65， and TLR4 in lung tissue was decreased （P<0.01）. ConclusionZingiberis Rhizoma Recens alcohol extract may play a protective role in LPS-induced acute lung injury in mice by inhibiting the TLR4/NF-κB signaling pathway.

Lesión pulmonar aguda producida por transfusión (TRALI): Reporte de caso

Introducción: La lesión pulmonar aguda (TRALI) y la sobrecarga circulatoria (TACO) son las principales causas de morbilidad y mortalidad relacionadas con la transfusión. La TRALI se presenta durante o después de las transfusiones de plasma y sus derivados, o por inmunoglobulinas en alta concentración intravenosa; se asocia a procesos sépticos, cirugías y transfusiones masivas. La TACO es la exacerbación de manifestaciones respiratorias en las primeras 6 horas postransfusión. Reporte caso: Paciente de sexo masculino de 38 días de vida, ingresó al servicio de urgencias con un cuadro clínico de 8 días de evolución, caracterizado por dificultad respiratoria dado por retracciones subcostales y aleteo nasal sin otro síntoma asociado, con antecedentes de importancia de prematuridad y bajo peso al nacer. El reporte de hemograma arrojó cifras compatibles con anemia severa, por lo que requirió transfusión de glóbulos rojos empaquetados desleucocitados. El paciente presentó un cuadro respiratorio alterado en un periodo menor a 6 horas, por lo que se descartaron causas infecciosas y finalmente se consideró cuadro compatible con TRALI. Conclusiones: Se debe considerar una lesión pulmonar aguda relacionada con una transfusión de sangre si se produce una insuficiencia respiratoria aguda durante o inmediatamente después de la infusión de hemoderivados que contienen plasma.

Introduction: Acute lung injury (TRALI) and circulatory overload (TACO) are the main causes of transfusion-related morbidity and mortality. TRALI occurs during or after transfusions of plasma or its derivatives, or by immunoglobulins in high intravenous concentration; it is associated with septic processes, surgeries, and massive transfusions. TACO is the exacerbation of respiratory manifestations in the first 6 hours post transfusion. Case report: A 38-day-old male was admitted to the emergency department with clinical symptoms experienced over the course of 8 days and characterized by respiratory distress due to subcostal retractions and nasal flaring with no other associated symptoms. Important antecedents included prematurity and low birth weight. The hemogram report showed figures compatible with anemia, which benefited from transfusion of packed red blood cells without leukocytes. In a period of less than 6 hours, the patient presented altered respiratory symptoms, practitioners ruled out infectious causes and finally considered clinical signs compatible with TRALI. Conclusion: Acute lung injury related to blood transfusion should be considered if acute respiratory failure occurs during or immediately after infusion of plasma-containing blood products.

Effects of atelectatic areas on the surrounding lung tissue during mechanical ventilation in an experimental model of acute lung injury induced by lipopolysaccharide / Efeitos das áreas atelectásicas no tecido pulmonar circundante durante a ventilação mecânica em um modelo experimental de lesão pulmonar aguda induzida por lipopolissacarídeo

ABSTRACT Objective: To assess the effect of atelectasis during mechanical ventilation on the periatelectatic and normal lung regions in a model of atelectasis in rats with acute lung injury induced by lipopolysaccharide. Methods: Twenty-four rats were randomized into the following four groups, each with 6 animals: the Saline-Control Group, Lipopolysaccharide Control Group, Saline-Atelectasis Group, and Lipopolysaccharide Atelectasis Group. Acute lung injury was induced by intraperitoneal injection of lipopolysaccharide. After 24 hours, atelectasis was induced by bronchial blocking. The animals underwent mechanical ventilation for two hours with protective parameters, and respiratory mechanics were monitored during this period. Thereafter, histologic analyses of two regions of interest, periatelectatic areas and the normally-aerated lung contralateral to the atelectatic areas, were performed. Results: The lung injury score was significantly higher in the Lipopolysaccharide Control Group (0.41 ± 0.13) than in the Saline Control Group (0.15 ± 0.51), p < 0.05. Periatelectatic regions showed higher lung injury scores than normally-aerated regions in both the Saline-Atelectasis (0.44 ± 0.06 x 0.27 ± 0.74 p < 0.05) and Lipopolysaccharide Atelectasis (0.56 ± 0.09 x 0.35 ± 0.04 p < 0.05) Groups. The lung injury score in the periatelectatic regions was higher in the Lipopolysaccharide Atelectasis Group (0.56 ± 0.09) than in the periatelectatic region of the Saline-Atelectasis Group (0.44 ± 0.06), p < 0.05. Conclusion: Atelectasis may cause injury to the surrounding tissue after a period of mechanical ventilation with protective parameters. Its effect was more significant in previously injured lungs.

RESUMO Objetivo: Avaliar o efeito da atelectasia durante a ventilação mecânica nas regiões periatelectáticas e pulmonares normais em um modelo de atelectasia em ratos com lesão pulmonar aguda induzida por lipopolissacarídeo. Métodos: Foram distribuídos aleatoriamente 24 ratos em quatro grupos, cada um com 6 animais: Grupo Salina-Controle, Grupo Lipopolissacarídeo-Controle, Grupo Salina-Atelectasia e Grupo Lipopolissacarídeo-Atelectasia. A lesão pulmonar aguda foi induzida por injeção intraperitoneal de lipopolissacarídeo. Após 24 horas, a atelectasia foi induzida por bloqueio brônquico. Os animais foram submetidos à ventilação mecânica por 2 horas com parâmetros ventilatórios protetores, e a mecânica respiratória foi monitorada durante esse período. Em seguida, foram realizadas análises histológicas de duas regiões de interesse: as áreas periatelectásicas e o pulmão normalmente aerado contralateral às áreas atelectásicas. Resultados: O escore de lesão pulmonar foi significativamente maior no Grupo Controle-Lipopolissacarídeo (0,41 ± 0,13) do que no Grupo Controle-Solução Salina (0,15 ± 0,51), com p < 0,05. As regiões periatelectásicas apresentaram escores maiores de lesão pulmonar do que as regiões normalmente aeradas nos Grupos Atelectasia-Solução Salina (0,44 ± 0,06 versus 0,27 ± 0,74, p < 0,05) e Atelectasia-Lipopolissacarídeo (0,56 ± 0,09 versus 0,35 ± 0,04, p < 0,05). O escore de lesão pulmonar nas regiões periatelectásicas foi maior no Grupo Atelectasia-Lipopolissacarídeo (0,56 ± 0,09) do que na região periatelectásica do Grupo Atelectasia-Solução Salina (0,44 ± 0,06), p < 0,05. Conclusão: A atelectasia pode causar lesão no tecido circundante após um período de ventilação mecânica com parâmetros ventilatórios protetores. Seu efeito foi mais significativo em pulmões previamente lesionados.

Diagnóstico por imagen de abscesos hepáticos y pulmonares por estreptococos del grupo viridans. Presentación de caso / Imaging diagnosis of liver and lung abscesses due to viridans streptococci. Case presentation

Resumen El Streptococcus viridans es conocido más comúnmente como agente infeccioso en las endocarditis, sin embargo, poco se conoce sobre su potencial infeccioso en otros órganos o sistemas, donde ha demostrado una elevada mortalidad. El reconocimiento del Streptococcus viridans como agente productor de abscesos en otras localizaciones como a nivel hepático o pulmonar, permitirá un diagnóstico oportuno mediante los distintos métodos de imagen, reduciendo las graves consecuencias para el paciente y los tiempos de hospitalización. Se presenta el caso de un paciente del sexo masculino de 33 años de edad sin antecedentes crónico degenerativos, que inició con sintomatología 7 meses previos a su ingreso, con fiebre intermitente, fatiga, astenia, anorexia y pérdida de peso. A la exploración física presentó dolor a la palpación media y profunda en hipocondrio derecho, en el panel de laboratorios presentó llamativa neutrofilia, en la tomografía de tórax y abdomen se mostró lesión cavernomatosa en pulmón y quistes complicados hepáticos, a los cuales se les realizó drenaje percutáneo guiado por ultrasonido, con envío de muestras a cultivo con resultado positivo para Streptococcus viridans, lo que permitió brindar el tratamiento dirigido al paciente, y que remitiera la enfermedad.

Abstract Streptococcus viridans is more commonly known as an infectious agent in endocarditis, however, little is known about its infectious potential in other organs or systems, where it has shown high mortality. The recognition of Streptococcus viridans as an abscess-producing agent in other locations, such as the liver or lungs, will allow timely diagnosis using different imaging methods, reducing serious consequences for the patient and hospitalization times. We present the case of a 33-year-old male patient with no chronic degenerative history, who started symptoms 7 months prior to admission, with intermittent fever, fatigue, asthenia, anorexia and weight loss, on physical examination he presented pain at the medium and deep palpation in the right hypochondrium, in the laboratory panel I present striking neutrophilia, in the tomography of the thorax and abdomen a cavernous lesion in the lung and complicated hepatic cysts are shown, to which percutaneous drainage guided by ultrasound is performed, with sending of cultured samples with a positive result for Streptococcus viridans. Thus, allowing treatment to be provided to the patient, thereby achieving remission of the disease.

Ischemic Postconditioning Attenuates Myocardial Ischemia-Reperfusion-Induced Acute Lung Injury by Regulating Endoplasmic Reticulum Stress-Mediated Apoptosis

ABSTRACT Objective: To explore the effect of ischemic postconditioning on myocardial ischemia-reperfusion-induced acute lung injury (ALI). Methods: Forty adult male C57BL/6 mice were randomly divided into sham operation group (SO group), myocardial ischemia-reperfusion group (IR group), ischemic preconditioning group (IPRE group) and ischemic postconditioning group (IPOST group) (10 mice in each group). Anterior descending coronary artery was blocked for 60 min and then reperfused for 15 min to induce myocardial IR. For the IPRE group, 3 consecutive cycles of 5 min of occlusion and 5 minutes of reperfusion of the coronary arteries were performed before ischemia. For the IPOST group, 3 consecutive cycles of 5 min reperfusion and 5 minutes of occlusion of the coronary arteries were performed before reperfusion. Pathological changes of lung tissue, lung wet-to-dry (W/D) weight ratio, inflammatory factors, oxidative stress indicators, apoptosis of lung cells and endoplasmic reticulum stress (ERS) protein were used to evaluate lung injury. Results: After myocardial IR, lung injury worsened significantly, manifested by alveolar congestion, hemorrhage, structural destruction of alveolar septal thickening, and interstitial neutrophil infiltration. In addition, lung W/D ratio was increased, plasma inflammatory factors, including interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-17A, were increased, malondialdehyde (MDA) activity of lung tissue was increased, and superoxide dismutase (SOD) activity was decreased after myocardial IR. It was accompanied by the increased protein expression levels of ERS-related protein glucose regulatory protein 78 (GRP78), CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), and caspase-12, and the increased apoptotic indices of lung tissues. Conclusion: IPOST can effectively improve myocardial IR-induced ALI by inhibiting ERS-induced apoptosis of alveolar epithelial cells.

Rinitis alérgica asociada al grado de compromiso pulmonar por COVID-19 en pacientes de un hospital general peruano / Allergic rhinitis associated with the degree of pulmonary involvement due to COVID-19 in patients from a peruvian general hospital

Objetivos. Evaluar la asociación entre rinitis alérgica y el grado de compromiso pulmonar en pacientes con COVID-19 y evaluar las frecuencias de las variables principales. Materiales y métodos. Se realizó un estudio de tipo observacional, transversal y analítico mediante la revisión de historias clínicas de pacientes atendidos en el Hospital Nacional Cayetano Heredia entre el año 2020 y 2021 con diagnóstico de COVID-19. Se determinó el antecedente de rinitis alérgica, y el compromiso pulmonar se evaluó mediante una tomografía sin contraste usando el puntaje tomográfico (PT), además de, variables sociodemográficas y clínicas. Se estimaron razones de prevalencias tanto crudas (RP) como ajustadas (RPa) con sus respectivos intervalos de confianza (IC) al 95% y se empleó un modelo lineal generalizado de la familia Poisson con función de enlace logarítmica y varianzas robustas. Resultados. Se evaluaron 434 pacientes predominantemente varones, mayores de 60 años y sin antecedentes médicos relevantes. El 56,2% tenía el antecedente de rinitis alérgica y el 43,1% tuvo un compromiso pulmonar moderado a severo. En el modelo de regresión ajustado, se encontró que el antecedente de rinitis alérgica disminuyó la gravedad de COVID-19 evaluada a través del compromiso pulmonar según el PT (RPa: 0,70; IC 95%: 0,56-0,88; p=0,002). Conclusiones. El antecedente de rinitis alérgica representó una disminución en la gravedad de COVID-19 según el PT score del 30,0% en pacientes hospitalizados.

Objectives. To evaluate the association between allergic rhinitis and the degree of pulmonary involvement in patients with COVID-19 and to determine the frequencies of the main variables. Materials and methods. An observational, cross-sectional and analytical study was carried out by reviewing the medical records of patients diagnosed with COVID-19 from the Cayetano Heredia National Hospital between 2020 and 2021. We obtained information regarding the history of allergic rhinitis; pulmonary involvement was assessed by non-contrast tomography results using the chest computed tomography (CT) score. Data regarding sociodemographic and clinical variables was also obtained. Both crude (PR) and adjusted (aPR) prevalence ratios with their respective 95% confidence intervals (CI) were estimated. We also used a generalized linear Poisson family model with log link function and robust variances. Results. We evaluated 434 patients, who were mostly male, older than 60 years and had no relevant medical history. Of these, 56.2% had a history of allergic rhinitis and 43.1% had moderate to severe pulmonary involvement. The adjusted regression model showed that the history of allergic rhinitis reduced the severity of COVID-19 according to the pulmonary involvement assessed by the CT score (aPR: 0.70; 95%CI: 0.56-0.88; p=0.002). Conclusions. The history of allergic rhinitis resulted in a 30.0% decrease in COVID-19 severity according to the CT score in hospitalized patients.

Changes of complement fragment C3a and its receptor in lung injury induced by silica nanoparticles / 环境与职业医学

Background Silica nanoparticles (SiNPs) enter the human body through respiratory tract, digestive tract, and skin, causing body damage. Lung is one of the main damaged organs. Objective To observe the expressions of complement activated fragment C3a and its receptor C3aR in the lungs of mice exposed to SiNPs through respiratory tract, and to explore the involvement of C3a/C3aR in lung injury induced by SiNPs exposure. Methods The ultrastructure of SiNPs (particle size 5-20 nm) was determined under a transmission electron microscope, and the hydrodynamic diameter and surface Zeta potential of SiNPs were determined using a nanoparticle size analyzer. A total of 88 SPF C57BL/6J mice were randomly divided into five groups: a blank control group without any treatment (14 mice), a vehicle control group treated with 50 μL stroke-physiological saline solution by intratracheal instillation (14 mice), and three SiNPs exposure groups (low-dose group, medium-dose group, and high-dose group with 20 mice in each group, who were given 50 μL SiNPs suspension of 7, 21, and 35 mg·kg−1 respectively and exposed once every 3 days for 5 times). The mice were anesthetized on day 1 (1-day model group) and day 15 (15-day model group) after exposure, then sacrificed after extraction of bronchoalveolar lavage fluid (BALF), and lung tissues were retained. The morphological changes of lung tissues were observed by HE staining, the expression level of C3a in BALF was detected by enzyme-linked immunosorbent assay, the deposition of C3a and C3aR in lung tissues were observed by immunohistochemistry, the protein expression level of C3aR was determined by Western blotting, and the localization and semi-quantitative detection of C3a and C3aR in lung tissues was observed by immunofluorescence. Results SiNPs agglomerated in stroke-physiological saline solution. The average hydrodynamic diameter was (185.60±7.39) nm and the absolute value of Zeta potential was (43.33±0.76) mV. The condition of mice in the 1-day model group and the 15-day model group was good, while 2 mice died in the medium-dose group of the 1-day model group due to misoperation. The autopsy results of the two mice showed congestion of the lung tissue, emphysema, and no imperfection of trachea integrity. No death was observed in other dose groups. The HE staining results showed pathological damage to the mouse lung, including alveolar wall thickening and inflammatory cell infiltration after SiNPs exposure. The pathological damage became more serious with the increase of dose. Regarding pathological changes, the 15-day model group was slightly relieved compared with the 1-day model group, but there were still pathological changes. The enzyme-linked immunosorbent assay results showed that there was no difference in the expression level of C3a between the blank control group and the vehicle control group (P＞0.05), the expression levels of C3a in the medium-dose group and the high-dose group were significantly higher than that in the vehicle control group (P<0.05). The immunohistochemistry results showed that C3a deposition was consistent with the enzyme-linked immunosorbent assay results. The Western blotting and the immunohistochemistry results showed that C3aR expression was low in the blank control group and the vehicle control group, while the expression in each dose group tended to increase with the increase of dose. The immunofluorescence results showed that the fluorescence signals of C3a and C3aR were weak in the blank control group and the vehicle control group in the 1-day model group and the 15-day model group, while the fluorescence signals in the lung tissues of mice in the SiNPs exposure groups tended to increase with the increase of dose. Conclusion The increased expressions of C3a and C3aR in complement activation may be related to lung injury induced by intratracheal instillation of SiNPs, suggesting that C3a/C3aR may be involved in lung injury induced by SiNPs exposure.

Mechanism of racanisodamine on alleviating radiation-induced lung injury in mice / 中华放射医学与防护杂志

Objective:To investigate the protective effect of racanisodamine on lung injury in mice exposed to irradiation.Methods:C57BL/6 mice were randomly divided into control group, racanisodamine group, 18 Gy irradiation group (model group) and racanisodamine combined with 18 Gy irradiation group (treatment group), with 5 mice in each group. The mice in the treatment group received racanisodamine (5 mg/kg) intraperitoneally 3 d before irradiation and contained the whole experiments. Then, single chest irradiation of 18 Gy X-rays was performed both in the model and treatment groups. The racanisodamine group and treatment group received racanisodamine intraperitoneally once a day until 6 weeks after irradiation. The mice were killed at 6 weeks after irradiation. The lung histopathology was observed by HE staining. Serum and bronchial alveolar lavage fluid (BALF) inflammatory cytokines such as TNF-α, IL-1β and IL-6 were determined by ELISA method. Cell senescence was detected by SA-β-Gal staining. The expressions of Nrf2, p-Nrf2 and p62 in lung tissue were performed by immunehistochemistry and Western blot assays.Results:Compared with the model group, the scores of HE staining were decreased ( t=8.66, P<0.01), the number of infiltrated inflammatory cells in BALF were decreased ( t=10.70, P<0.01), and protein concentration in BALF had lower levels ( t=6.75, P<0.01), the serum TNF-α, IL-1β and IL-6 were decreased significantly ( t=8.17, 4.58, 6.54, P<0.01), the activity of SA-β-gal was decreased, and the expressions of Nrf2, p-Nrf2 were enhanced ( t=6.42, 7.30, P<0.01), while the expression of p62 was reduced ( t=4.62, P<0.01) in the treatment group. Conclusions:Racanisodamine plays the protective effect of radiation-induced lung injury by alleviating inflammation associating with the activating of Nrf2-related pathway, which reversed radiation-induced cell senescence.

Protective effect and mechanism of ophiopogonin D on radiation-induced lung injury in mice / 中华放射医学与防护杂志

Objective:To investigate the protective effect and mechanism of ophiopogonin D on lung injury induced by radiation in mice.Methods:A total of 60 female C57BL/6 mice were randomly divided into 4 groups: control group, irradiation group, irradiation+ ophiopogonin D group and irradiation+ dexamethasone group, with 15 mice in each group. The mice were irradiated with a single dose of 6 MV X-rays of 15 Gy. Three days before irradiation, the mice in irradiation+ ophiopogonin D group were intraperitoneally injected with 10 mg/kg ophiopogonin D solution. The mice in irradiation+ dexamethasone group were intraperitoneally injected with 10 mg/kg dexamethasone solution. The mice in control group and irradiation group were intraperitoneally injected with normal saline once a day until 1 week after irradiation. Tissue samples were collected at 3 d, 1 week, and 6 weeks post-irradiation. Hematoxylin-eosin (HE) staining and Masson′s trichrome staining were used to observe the pathological changes of lung tissue. The expressions of 8-hydroxy-deoxyguanosine (8-OHdG), p53, p53 up-regulated apoptosis factor (PUMA), cysteine aspartate proteolytic enzyme-3 (caspase-3), Collagen Ⅰ and Collagen Ⅲ were observed by immunohistochemistry. Western blot was used to verify the expressions of apoptosis related proteins including p53, PUMA and caspase-3.Results:HE staining of lung tissue showed that ophiopogonin D could reduce hemorrhage, exudation, edema and inflammatory infiltration in lung tissue 1 week post irradiation. Moreover, ophiopogonin D reduced the expression of 8-OHdG ( t=8.39, P < 0.05), the oxidative stress, and the expressions of p53, PUMA, caspase-3 apoptosis-related proteins ( t=12.60, 5.92, 7.00, P < 0.05), and inhibited the apoptosis of alveolar epithelial cells and alleviated other damage in the irradiated lung tissue 1 week post-irradiation. Ophiopogonin D also reduced collagen deposition in lung tissue 6 weeks after irradiation, and reduced the expression of transforming growth factor (TGF-β1) ( t=9.32, 8.97, 6.83, P < 0.05) and interleukin-6 ( t=8.22, 7.80, 8.28, P < 0.05) in the blood of mice at 3 d, 1 week, and 6 weeks after irradiation. At 6 weeks after exposure, ophiopogonin D reduced the production of Collagen Ⅰ and Collagen Ⅲ in the lung interstitium ( t=6.41, 7.50, P < 0.05), and alleviated the pulmonary fibrosis in the late stage of radiation. Conclusions:Ophiopogonin D has protective effects on lung injury caused by radiation, including the alleviation of early radiation pneumonia and late pulmonary fibrosis, by reducing oxidative stress, the expression of inflammation-related factors, apoptosis of lung tissue, and collagen production.

Construction of a risk warning model for acute lung injury caused by Staphylococcus aureus infection / 中华传染病杂志

Objective:To investigate the risk factors of acute lung injury (ALI) caused by Staphylococcus aureus infection, and to construct a risk warning model. Methods:Patients with Staphylococcus aureus infection confirmed by sputum or blood culture admitted to the Affiliated Hospital of Jiangnan University from January 1, 2020 to May 10, 2022 were enrolled and divided into ALI group and non-ALI group. The age, smoking status, C-reactive protein (CRP), procalcitonin (PCT), neutrophil-to-lymphocyte ratio (NLR), albumin, oxygenation index and other clinical data were compared between the two groups. Univariate analysis was performed by using independent sample t test and chi-square test. Binary logistic regression analysis was used to screen the independent risk factors of ALI caused by Staphylococcus aureus infection, and a risk warning model was constructed. The receiver operator characteristic (ROC) curve was used to evaluate the predictive ability of the model. Results:There were 96 cases of Staphylococcus aureus infection, including 68 cases (70.8%) in ALI group, of which 41 cases (60.3%) were positive in sputum culture and 27 cases (39.7%) were positive in blood culture. Compared with the non-ALI group, the proportion of patients aged ≥60 years in ALI group was lower (58.8%(40/68) vs 64.3%(18/28)), the proportion of smoking was higher (58.8%(40/68) vs 35.7%(10/28)), and the differences were both statistically significant ( χ2=0.76 and 0.03, respectively, both P<0.05). The levels of CRP, PCT and NLR in the ALI group were all higher than those in non-ALI group, while oxygenation index and albumin level were both lower, and the differences were all statistically significant ( t=-5.28, -3.46, -9.87, 12.83 and 3.08, respectively, all P<0.05). Binary logistic regression analysis showed that CRP (odds ratio ( OR)=1.973, 95% confidence interval (95% CI) 0.956 to 2.989), PCT ( OR=3.734, 95% CI 1.014 to 13.746), NLR ( OR=1.152, 95% CI 1.058 to 2.254) and albumin ( OR=1.527, 95% CI 1.110 to 2.102) were independent risk factors for ALI caused by Staphylococcus aureus infection. The areas under the ROC curve of CRP, PCT, NLR, albumin and the risk warning model constructed from the combination of four risk factors were 0.69, 0.81, 0.83, 0.78 and 0.93, respectively. The sensitivities were 65.14%, 89.91%, 84.40%, 56.88% and 98.17%, respectively. The specificities were 62.37%, 60.22%, 65.59%, 80.64% and 93.55%, respectively. The accuracy of the effectiveness test of the risk warning model was 84.97%. Conclusions:CRP, PCT, NLR and albumin are the independent risk factors for ALI caused by Staphylococcus aureus infection. The risk warning model based on the above factors has a good early warning effect on ALI caused by Staphylococcus aureus infection.

Protective effect of barium chloride pretreatment on lung in mice with acute respiratory distress syndrome / 中华危重病急救医学

Objective:To explore whether barium chloride (BaCl 2) preconditioning has the protective effect on lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) model in mice and the possible mechanism. Methods:Sixty 8-12 week old healthy C57BL/6 male mice were randomly divided into control group, ARDS model group and BaCl 2 pretreatment group, with 20 mice in each group. The BaCl 2 pretreatment group was continuously injected with BaCl 2 (4 mg/kg through the tail vein) for 3 days before ARDS model establishment. ARDS model was established by intratracheally injecting (3 mg/kg) LPS. The control group was intratracheally given the same volume of 0.9% normal saline. On 24th hour after ARDS model establishment, some mice were sacrificed for obtaining fresh lung tissue. And the right lower lobe of the lung was separated for observing the pathological changes of lung tissue while the left lung tissue was used to measure the wet/dry weight ratio (W/D) of the lung. Some mice were sacrificed for observing pulmonary microvascular permeability at 2nd hours after injecting Evans blue (EB) through tail vein. The left mice were killed for alveolar lavage to measure the levels of tumor necrosis factor-α (TNF-α) via enzyme linked immunosorbent assay (ELISA). Results:Comparing with the control group, ARDS model group showed typical ARDS pathological changes, which included the increased W/D ratio (4.951±0.161 vs. 3.449±0.299, P < 0.01) and the content of EB in the lung tissue (μg/g: 0.130±0.027 vs. 0.085±0.011, P < 0.01), the damaged alveolar wall structure, lung congestion and exudates in the alveoli, as well as amounts of inflammatory cells. The pathological score of lung injury (10.33±1.15 vs. 1.67±0.58) and the level of TNF-α in BALF (ng/L: 900.85±247.80 vs. 68.21±5.79) were significantly increased in the ARDS model group (both P < 0.01). Comparing with the ARDS model group, the lung W/D ratio (4.620±0.125 vs. 4.951±0.161) and the EB content in the lung tissue (μg/g: 0.108±0.011 vs. 0.130±0.027) of BaCl 2 pretreatment group were significantly reduced (both P < 0.01). And the damaged pulmonary structural BaCl 2 pretreatment group were significantly alleviated. In addition, the pulmonary pathological score (5.00±1.00 vs. 10.33±1.15) and the level of TNF-α in BALF (ng/L: 169.16±73.33 vs. 900.85±247.80) were significantly decreased (both P < 0.01). Conclusion:Barium chloride pretreatment can improve the lung histopathological changes of ARDS model mice induced by LPS by reducing the permeability of pulmonary capillaries and local inflammatory reaction.Barium chloride has the protective effect against LPS attack in mice model of ARDS.

Effect of SIRT1 regulating Nrf2/HO-1 signaling pathway on sepsis-induced acute lung injury / 中华危重病急救医学

Objective:To investigate whether silence information regulator 1 (SIRT1) could regulate nuclear factor E2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) signaling pathway and its role in acute lung injury (ALI) in sepsis rats.Methods:Twenty-four male Sprague-Dawley (SD) rats were randomly divided into sham operation group (Sham group), cecal ligation and puncture (CLP) induced sepsis group (CLP group), sepsis+SIRT1 specific agonist group (CLP+SRT1720 group,10 mg/kg SRT1720 was intraperitoneally injected 2 hours before CLP), sepsis+SIRT1 specific inhibitor group (CLP+EX527 group, 10 mg/kg EX527 was intraperitoneally injected 2 hours before CLP), with 6 rats in each group. The rats were killed 24 hours after modeling and their lung tissues were taken for pathological score (Smith score), superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), tumor necrosis factor-α (TNF-α), interleukins (IL-6, IL-1β), and SIRT1, Nrf2 and HO-1 mRNA and protein expression were detected.Results:The lung tissue of the CLP group mice was severely damaged, the alveolar interval was widened and a large number of inflammatory cells infiltrated, and there was visible pulmonary capillary hyperemia. The Smith score, the levels of TNF-α, IL-6, IL-1β, MDA and 8-OHdG were significantly increased, the levels of SOD, GSH, SIRT1, Nrf2 and HO-1 were significantly decreased in CLP group. After using SIRT1 specific agonist, the lung injury in CLP+SRT1720 group was significantly alleviated compared with that in CLP group, Smith score and lung tissue TNF-α, IL-6, and IL-1β levels were significantly decreased [Smith score: 2.83±0.75 vs. 5.67±0.52, TNF-α (ng/L): 36.78±5.36 vs. 66.99±5.44, IL-6 (ng/L): 23.97±3.76 vs. 45.70±4.16, IL-1β (ng/L): 16.76±1.39 vs. 39.64±2.59, all P < 0.05], SOD activity and GSH content increased [SOD (kU/g): 115.88±3.31 vs. 101.65±1.09, GSH (μmol/g): 8.42±0.81 vs. 5.74±0.46, both P < 0.05], MDA and 8-OHdG contents decreased [MDA (μmol/g): 5.24±0.33 vs. 9.86±0.66, 8-OHdG (ng/L): 405.76±8.54 vs. 647.12±10.64, both P < 0.05], the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 were increased [SIRT1 mRNA (2 -ΔΔCT): 1.49±0.15 vs. 0.64±0.03, Nrf2 mRNA (2 -ΔΔCT): 1.19±0.08 vs. 0.84±0.02, HO-1 mRNA (2 -ΔΔCT): 1.80±0.41 vs. 0.64±0.11, SIRT1 protein (SIRT1/β-actin): 1.03±0.06 vs. 0.52±0.05, Nrf2 protein (Nrf2/β-actin): 1.14±0.10 vs. 0.63±0.05, HO-1 protein (HO-1/β-actin): 1.01±0.11 vs. 0.73±0.03, all P < 0.05]. The lung injury in CLP+EX527 group was more severe than that in CLP group, Smith score and lung tissue TNF-α, IL-6, IL-1β levels were significantly increased [Smith score: 8.00±0.89 vs. 5.67±0.52, TNF-α (ng/L): 87.15±4.23 vs. 66.99±5.44, IL-6 (ng/L): 66.79±2.93 vs. 45.70±4.16, IL-1β (ng/L): 58.99±2.12 vs. 39.64±2.59, all P < 0.05], SOD activity and GSH content decreased [SOD (kU/g): 72.84±3.85 vs. 101.65±1.09, GSH (μmol/g): 3.30±0.67 vs. 5.74±0.46, both P < 0.05], the contents of MDA and 8-OHdG were increased [MDA (μmol/g): 14.14±0.70 vs. 9.86±0.66, 8-OHdG (ng/L): 927.66±11.47 vs. 647.12±10.64, both P < 0.05], the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 were decreased [SIRT1 mRNA (2 -ΔΔCT): 0.40±0.07 vs. 0.64±0.03, Nrf2 mRNA (2 -ΔΔCT): 0.48±0.07 vs. 0.84±0.02, HO-1 mRNA (2 -ΔΔCT): 0.27±0.14 vs. 0.64±0.11, SIRT1 protein (SIRT1/β-actin): 0.20±0.05 vs. 0.52±0.05, Nrf2 protein (Nrf2/β-actin): 0.45±0.01 vs. 0.63±0.05, HO-1 protein (HO-1/β-actin): 0.36±0.08 vs. 0.73±0.03, all P < 0.05]. Conclusions:In the rat model of ALI induced by sepsis, SIRT1 can regulate the activation of Nrf2/HO-1 signaling pathway, upregulate the expression of downstream antioxidant enzymes, reduce oxidative stress injury, and then alleviate the ALI induced by sepsis in rats.

Research progress on mechanism of biotrauma caused by ventilation-induced lung injury / 中华危重病急救医学

Mechanical ventilation is an advanced life support treatment for patients with acute respiratory failure. While stabilizing respiratory function, it also acts as an injury factor to exacerbate or lead to lung injury, that is, ventilation-induced lung injury (VILI). There may be a more subtle form of damage to VILI known as "biotrauma". However, the mechanism of biotrauma in VILI is still unclear. This article intends to review the mechanism of biotrauma of VILI from the aspects of inflammatory response, oxidative stress and complement activation, in order to provide a new strategy for clinical prevention and treatment of biotrauma caused by VILI.

MicroRNA21-5p alleviates hyperoxia-induced acute lung injury in rats through activating phosphatidylinositol 3 kinase/serine-threonine protein kinase signaling pathway by regulating type Ⅱ alveolar epithelial cell apoptosis / 中华危重病急救医学

Objective:To investigate whether microRNA-21-5p (miR-21-5p) alleviates hyperoxia-induced acute lung injury (HALI) through activating the phosphatidylinositol 3 kinase/serine-threonine protein kinase (PI3K/Akt) signaling pathway by regulating apoptosis of type Ⅱ alveolar epithelial cell (AECⅡ).Methods:Seventy-two male Sprague-Dawley (SD) rats were divided into normozone-controlled group, HALI group, PI3K/Akt signaling pathway inhibitor LY294002+HALI group (LY+HALI group), miR-21-5p overexpression+LY294002+HALI group (miR-21-5p+LY+HALI group), miR-21-5p overexpression+HALI group (miR-21-5p+HALI group), and dimethyl sulfoxide (DMSO)+HALI group by random number table method with 12 rats in each group. Animal models of HALI were prepared using 95% concentrations of oxygen. The animals in the normozone-controlled group were fed normally under normoxia. Transfection of lung tissue by miR-21-5p adeno-associated viral vector AAV6-miR-21-5p was performed by instillation of 200 μL titer (1×10 12 TU/mL) through a tracheal catheter 3 weeks prior to modeling. DMSO and LY294002 were administered via the tail vein at 0.3 mg/kg 1 hour before modeling. After 48 hours of modeling, carotid artery blood was collected to detect oxygenation index (OI) and respiratory index (RI), and real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect miR-21-5p expression. Lung tissue was collected, and the levels of inflammatory factors including tumor necrosis factor-α (TNF-α) and interleukins (IL-6, IL-1β) were measured by enzyme-linked immunosorbent assay (ELISA), and the ratio of pulmonary wet/dry weight (W/D) was determined, and the pathological changes of lung histopathology were observed under the light microscopy after hematoxylin-eosin (HE) staining. Each group was purified AECⅡ cells from 6 rats, the apoptosis rate was detected by flow cytometry, and the expression levels of phosphatase and tensin homologous gene (PTEN), and proteins from the PI3K/Akt signaling pathway were detected by Western blotting. Results:Compared with the normozone-controlled group, alveolar septal thickening and massive inflammatory cell infiltration were found after hyperoxia exposure, RI, inflammatory factors, lung W/D ratio, pathological score, AECⅡ cells early apoptosis rate, PTEN protein expression and phosphorylation level of Akt were increased, while OI and miR-21-5p expression were decreased, indicating the successful preparation of the model. After pretreatment, LY294002 could aggravate the pathological injury of lung tissue in HALI rats, RI, inflammatory factors and lung W/D ratio were further increased, and OI was further reduced compared with HALI group. At the same time, it could promote the AECⅡ cell apoptosis, further up-regulate the expression of PTEN, and reduce the phosphorylation of Akt. However, miR-21-5p pretreatment could negatively regulate PTEN, activate PI3K/Akt signal pathway, inhibit AECⅡ cell apoptosis, and reduce HALI, which was shown by the decreased level of inflammatory factors in miR-21-5p+LY+HALI group compared with LY+HALI group [TNF-α (μg/L): 100.33±3.48 vs. 116.55±2.53, IL-6 (ng/L): 141.06±3.70 vs. 161.31±3.59, IL-1β (μg/L): 90.82±3.69 vs. 112.23±2.87, all P < 0.05], RI, lung injury pathology score, lung W/D ratio, and AECⅡ cell early apoptosis rate were significantly decreased [RI: 0.81±0.02 vs. 1.05±0.07, pathology score: 0.304±0.008 vs. 0.359±0.007, lung W/D ratio: 5.29±0.03 vs. 5.52±0.08, apoptosis rate: (27.20±2.34)% vs. (34.17±1.49)%, all P < 0.05], OI and expressions of miR-21-5p were significantly increased [OI (mmHg, 1 mmHg≈0.133 kPa): 266.71±2.75 vs. 230.12±4.04, miR-21-5p (2 -ΔΔCt): 2.21±0.13 vs. 0.33±0.03, both P < 0.05], and PTEN protein expression in AECⅡ cell was significantly reduced (PTEN/GAPDH: 0.50±0.06 vs. 0.93±0.06, P < 0.05), and phosphorylation level of Akt was significantly increased [phosphorylated Akt (p-Akt) protein (p-Akt/GAPDH): 0.86±0.05 vs. 0.56±0.06, P < 0.05]. Conclusion:miR-21-5p attenuates HALI by inhibiting AECⅡ cell apoptosis, possibly through negative regulation of PTEN to activate PI3K/Akt signaling pathway.

Effect of ventilator-induced lung injury on blood-brain barrier permeability in rats / 中华危重病急救医学

Objective:To observe the effect of ventilator-induced lung injury (VILI) on blood-brain barrier permeability in rats.Methods:Forty-eight healthy clean male Sprague-Dawley (SD) rats were randomly divided into sham operation (Sham) group, low tidal volume (LVT) mechanical ventilation group (LVT group), normal tidal volume (NVT) mechanical ventilation group (NVT group) and high tidal volume (HVT) mechanical ventilation group (HVT group) with 12 rats in each group. After anesthesia, rats in the Sham group were intubated and kept spontaneous breathing. The rats in different tidal volume (VT) groups were mechanically ventilated by endotracheal intubation with VT of 6 mL/kg (LVT group), 10 mL/kg (NVT group), and 20 mL/kg (HVT group), respectively. The inspiration-expiration ratio of the three groups was 1∶1, the ventilation frequency was 40 times/min, and the ventilation time was 3 hours. At the end of the experiment, the bronchoalveolar lavage fluid (BALF) of rats was collected, and the levels of pro-inflammatory factors [tumor necrosis factor-α (TNF-α), interleukins (IL-1β and IL-6)] in BALF were detected by enzyme-linked immunosorbent assay (ELISA). The lung tissues of rats were collected, and the lung wet/dry weight (W/D) ratio was calculated. The pathological changes of lung tissues were observed under light microscopy after hematoxylin-eosin (HE) staining, and lung injury scores were performed. The brain tissue of rats was taken to measure the brain water content, and the Evans blue (EB) content of brain tissue was measured to reflect the permeability of the blood-brain barrier. The tight junction proteins in the brain tissues were detected by Western blotting.Results:After 3 hours of mechanical ventilation, with the increase of VT, the degree of lung injury in VILI rats gradually increased. When VT reached 20 mL/kg, lung tissue structure was significantly injured, alveolar wall edema, alveolar congestion, lung interstitial thickening, a large number of inflammatory cells infiltrated, and the lung injury score, lung W/D ratio, and the levels of TNF-α, IL-1β and IL-6 in BALF were significantly higher than those in the Sham group [lung injury score: 10.6±1.1 vs. 1.4±1.0, lung W/D ratio: 6.6±0.8 vs. 3.7±0.6, TNF-α(ng/L): 832.9±97.9 vs. 103.8±23.3, IL-1β (ng/L): 68.9±14.1 vs. 15.7±2.6, IL-6 (ng/L): 70.8±16.4 vs. 20.3±5.4, all P < 0.05]. Lung injury in rats was accompanied by aggravating brain injury. When VT reached 20 mL/kg, brain water content and EB content in brain tissue were significantly higher than those in the Sham group [brain water content: (85.4±3.6)% vs. (68.7±2.7)%, EB content in brain tissue (μg/g): 887±78 vs. 97±14, both P < 0.05], and the protein expressions of claudin-5, occluding and zonula occluden-1 (ZO-1) in the brain tissue were significantly lower than those in the Sham group [claudin-5 protein (claudin-5/β-actin): 0.67±0.12 vs. 1.45±0.19, occludin protein (occludin/β-actin): 0.48±0.11 vs. 0.99±0.21, ZO-1 protein (ZO-1/β-actin): 0.13±0.03 vs. 0.63±0.12, all P < 0.05]. Conclusion:VILI can induce brain edema and increase blood-brain barrier permeability in rats, which may be related to the down-regulation of tight junction protein expression in the brain tissue.

Effect of early thoracic paracentesis drainage on acute lung injury in severe acute pancreatitis / 临床肝胆病杂志

Objective To investigate the effect of early thoracic paracentesis drainage for pleural effusion with a small or moderate volume on acute lung injury in patients with severe acute pancreatitis (SAP). Methods A retrospective analysis was performed for the clinical data of 107 patients with SAP who were admitted to The General Hospital of Western Theater Command from January 2015 to December 2021, and according to whether thoracic paracentesis drainage was performed within the first three days after admission, the patients were divided into thoracic paracentesis drainage group (TPD group with 51 patients) and non-thoracic paracentesis drainage group (N-TPD group with 56 patients).The two groups were compared in terms of laboratory markers and clinical outcome on days 5 and 10 after admission.The independent-samples t test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test was used for comparison of categorical data between two groups. Results Compared with the N-TPD group, the TPD group had a significantly shorter length of stay in the intensive care unit, a significantly shorter length of hospital stay, and significantly lower hospital costs (all P < 0.05), while there were no significant differences between the TPD group and the N-TPD group in mortality rate (9.8% vs 14.3%, χ 2 =0.502, P =0.478) and the incidence rate of sepsis (29.4% vs 44.6%, χ 2 =2.645, P =0.104).The TPD group had a significant reduction in the incidence rate of acute respiratory distress syndrome (ARDS)( χ 2 =6.038, P =0.043), as well as a significantly lower incidence rate of moderate ARDS than the N-TPD group (7.8% vs 21.4%, χ 2 =3.874, P =0.049).Compared with the N-TPD group, the TPD group had a significantly lower rate of use of mechanical ventilation (35.3% vs 57.2%, χ 2 =6.735, P =0.034) and a significantly lower proportion of patients receiving invasive mechanical ventilation (9.8% vs 26.8%, χ 2 =5.065, P =0.024).Compared with the N-TPD group, the TPD group had a significantly lower incidence rate of pulmonary infection (23.5% vs 42.9%, χ 2 =4.466, P =0.035) and a significantly shorter duration of systemic inflammatory response syndrome (11.2±5.0 days vs 16.8±4.7 days, t =5.949, P < 0.001).Compared with the N-TPD group, the TPD group had significantly better laboratory markers (high-sensitivity C-reactive protein, interleukin-1, interleukin-6, interleukin-8, tumor necrosis factor-α, arterial partial pressure of oxygen, oxygen saturation, and oxygenation index) and incidence rate of respiratory failure on days 5 and 10 after admission (all P < 0.05).On day 10 after admission, the TPD group had significantly better APACHE Ⅱ score and modified Mashall score than the N-TPD group (both P < 0.05). Conclusion For SAP patients with a small or moderate volume of pleural effusion, early thoracic paracentesis drainage can effectively improve acute lung injury, alleviate systemic inflammatory response, shorten the length of hospital stay, and reduce hospital costs.