Alveolar Lavage Research Articles

Effect of Targeted Nursing on Bronchoscopic Alveolar Lavage in the Treatment of Lobar Pulmonary Infection in Children

Objective: The aim of this study was to evaluate the impact of a targeted nursing intervention on the clinical outcomes of children with lobar pulmonary infection undergoing bronchoscopic alveolar lavage treatment. Methods: This retrospective study enrolled 100 children with lobar pulmonary infection admitted to our hospital between March 2019 and September 2021. The participants were divided into a control group (n=50) that received routine nursing care and an observation group (n=50) that underwent a targeted nursing intervention in addition to standard care. The primary outcomes assessed included the total clinical effectiveness rate, duration of symptom resolution (fever, cough, dyspnea), length of hospital stay, treatment compliance, and incidence of complications. Results: The total clinical effectiveness rate was significantly higher in the observation group compared to the control group (P<0.05). The time to resolution of fever, cough, and dyspnea was shorter in the observation group than the control group, with statistically significant differences (P<0.05). Treatment compliance was significantly better in the observation group than the control group (P<0.05). The incidence of complications was lower in the observation group than the control group, with a statistically significant difference (P<0.05). Conclusion: The implementation of a targeted nursing intervention in children with lobar pulmonary infection undergoing bronchoscopic alveolar lavage was associated with improved clinical effectiveness, faster symptom resolution, higher treatment compliance, and reduced complication rates compared to routine nursing care. These findings suggest that the adoption of specialized nursing strategies may optimize the outcomes of this vulnerable patient population and warrants further investigation and clinical implementation.

Revealing the mechanism: the influence of Baicalin on M1/M2 and Th1/Th2 imbalances in mycoplasma gallisepticum infection

Mycoplasma gallisepticum (MG) is a pathogen that induces chronic respiratory illnesses in chickens, leading to tracheal and lung injury, and eliciting immune reactions that support sustained colonization. Baicalin, a compound found in scutellaria baicalensis, exhibits anti-inflammatory, antioxidant, and antibacterial properties. This study aimed to investigate the potential of baicalin in alleviating lung and cell damage caused by MG by restoring imbalances in M1/M2 and Th1/Th2 differentiation and to explore its underlying mechanism. In this research, a model for M1/M2 polarization induced by MG was initially developed. Specifically, infection with MG at a multiplicity of infection (MOI) of 400 for 6 h represented the M1 model, while infection for 10 h represented the M2 model. The polarization markers were subsequently validated using qRT-PCR, ELISA, and Western blot analysis. Baicalin disrupts the activation of M1 cells induced by MG and has the potential to restore the balance between M1 and M2 cells, thereby mitigating the inflammatory damage resulting from MG. Subsequent studies on MG-infected chickens detected imbalances in M1/M2 and Th1/Th2 differentiation in alveolar lavage fluid, as well as imbalances in macrophages and Th cells in the lung. The M1/Th1 model was exposed to MG for 5 d, while the M2/Th2 model was infected with MG for 7 d. The utilization of both light and electron transmission microscopes revealed that the administration of baicalin resulted in a reduction in the number of M1 cells, a decrease in cytoplasmic vacuoles, restoration of mitochondrial swelling and chromatin agglutination, as well as alleviation of alveolar rupture and inflammatory cell infiltration. Furthermore, baicalin restored MG-induced M1/M2 and Th1/Th2 imbalances and inhibited the phosphorylation of p38 and p65 proteins, thereby hindering the activation of the TLR4-p38 MAPK/NF-κB pathway. This study provides insights into the potential long-term effects of baicalin in MG infection and offers a theoretical basis for practical applications.

Effect of macrophage-to-myofibroblast transition on silicosis.

The aim was to explore the effect of macrophage polarization and macrophage-to-myofibroblast transition (MMT) in silicosis. Male Wistar rats were divided into a control group and a silicosis group developed using a HOPE MED 8050 dynamic automatic dusting system. Murine macrophage MH-S cells were randomly divided into a control group and an SiO2 group. The pathological changes in lung tissue were observed using hematoxylin and eosin (HE) and Van Gieson (VG) staining. The distribution and location of macrophage marker (F4/80), M1 macrophage marker (iNOS), M2 macrophage marker (CD206), and myofibroblast marker (α-smooth muscle actin [α-SMA]) were detected using immunohistochemical and immunofluorescent staining. The expression changes in iNOS, Arg, α-SMA, vimentin, and type I collagen (Col I) were measured using Western blot. The results of HE and VG staining showed obvious silicon nodule formation and the distribution of thick collagen fibers in the lung tissue of the silicosis group. Macrophage marker F4/80 increased gradually from 8 to 32 weeks after exposure to silica. Immunohistochemical and immunofluorescent staining results revealed that there were more iNOS-positive cells and some CD206-positive cells in the lung tissue of the silicosis group at 8 weeks. More CD206-positive cells were found in the silicon nodules of the lung tissues in the silicosis group at 32 weeks. Western blot analysis showed that the expressions of Inducible nitric oxide synthase and Arg protein in the lung tissues of the silicosis group were upregulated compared with those of the control group. The results of immunofluorescence staining showed the co-expression of F4/80, α-SMA, and Col I, and CD206 and α-SMA were co-expressed in the lung tissue of the silicosis group. The extracted rat alveolar lavage fluid revealed F4/80+α-SMA+, CD206+α-SMA+, and F4/80+α-SMA+Col I+ cells using immunofluorescence staining. Similar results were also found in MH-S cells induced by SiO2. The development of silicosis is accompanied by macrophage polarization and MMT.

The effect of ethanol extracts of loulu flower on LPS-induced acute lung injury in mice

Ethnopharmacological relevanceIn Mongolian medicine, Loulu flower (LLF), the dried inflorescence of Rhaponticum uniflorum (L.) DC. from the Compositae family, has been used to clear heat and relieve toxicity for millennia, particularly in the treatment of pneumonia. Aim of this studyTo reveal the effects of LLF on mice with lipopolysaccharide (LPS)-stimulated acute lung injury (ALI) and elucidate the underlying mechanisms. Materials and methodsALI was established in BALB/c mice via nasal drops administration of LPS (5 mg/kg). The mice were then orally administrated with various doses of LLF extracts and the positive drug dexamethasone (DEX, 5 mg/kg), once daily for seven consecutive days. Last day, after being stimulated with LPS for 6h, the mice were closed dislocation of cervical vertebra, the serum, bronchus alveolar lavage fluid (BALF) and lung tissue were put into the EP tube and stored at −80 °C for further analysis. The changes of histopathology were tested by hematoxylin and eosin stain (H&E), the levels of, IL-1β, IL-18, TNF-α and IL-4 in BALF and serum were measured by ELISA. The pathways related to the treatment of ALI were predicted by network pharmacology. The expression levels of TLR4/NF-κB and NLRP3 signaling pathway-associated proteins, COX-2 and ERK were tested by western blotting. The levels of P65 and NLRP3 in lung tissues were determined by immunofluorescence analysis. ResultsLLF total extract and the extract parts could alleviate the inflammatory cell infiltration, thicken the alveolar walls in lung tissues, reduce the levels of IL-18, IL-1β in BALF, the TNF-α in both BALF and serum, meantime enhance the level of IL-4 in BALF and serum in mice with LPS-induced ALI. Our network pharmacology and comprehensive gene ontology analyses revealed the active constituents of LLF and the pathways, including TLR4/NF-κB, NLRP3 and MAPK signaling pathways, which play significant roles in ALI. Furthermore, both the total extract and its extraction portions suppressed the expressions of proteins related with the COX-2, p-ERK and TLR4/NF-κB signaling pathway (TLR4, p-IκB, p-p65), as well as the NLRP3 signaling pathway (NLRP3, cleaved caspase-1, caspase-1, IL-1β). ConclusionLLF could improve the pathological changes and reducing inflammatory reactions in mice induced by LPS. The mechanism may be related to the modulation of the TLR4/NLRP3 signaling pathways.

The impact of Astragaloside IV on the inflammatory response and gut microbiota in cases of acute lung injury is examined through the utilization of the PI3K/AKT/mTOR pathway.

Astragaloside IV (AS-IV) is a natural triterpenoid saponin compound with a variety of pharmacological effects, and several studies have clarified its anti-inflammatory effects, which may make it an effective alternative treatment against inflammation. In the study, we aimed to investigate whether AS-IV could attenuate the inflammatory response to acute lung injury and its mechanisms. Different doses of AS-IV (20mg·kg-1, 40mg·kg-1, and 80mg·kg-1) were administered to the ALI rat model, followed by collection of serum and broncho alveolar lavage fluid (BALF) for examination of the inflammatory response, and HE staining of the lung and colon tissues, and interpretation of the potential molecular mechanisms by quantitative real-time PCR (qRT-PCR), Western blotting (WB). In addition, fecal samples from ALI rats were collected and analyzed by 16S rRNA sequencing. AS-IV decreased the levels of TNF-α, IL-6, and IL-1β in serum and BALF of mice with Acute lung injury (ALI). Lung and colon histopathology confirmed that AS-IV alleviated inflammatory infiltration, tissue edema, and structural changes. qRT-PCR and WB showed that AS-IV mainly improved inflammation by inhibiting the expression of PI3K, AKT and mTOR mRNA, and improved the disorder of intestinal microflora by increasing the number of beneficial bacteria and reducing the number of harmful bacteria. AS-IV reduces the expression of inflammatory factors by inhibiting the PI3K/AKT/mTOR pathway and optimizes the composition of the gut microflora in AIL rats.

Herbacetin Inhibits Asthma Development by Blocking the SGK1/NF-κB Signaling Pathway.

Asthma severely interferes with people's lives through coughing, wheezing and inflammation of the lungs. Herbacetin is a class of natural compounds that inhibit the development of inflammation. However, whether Herbacetin inhibits asthma has not been definitively studied. Lipopolysaccharides (LPS)-induced lung epithelial (BASE-2B) cells injury model was established, and then the relief of damaged BASE-2B cells with different concentrations of Herbacetin was examined. The cell counting kit (CCK8) was used to detect the effect of Herbacetin on the proliferation ability in ovalbumin (OVA)-induced asthma mice model, and Western Blot and flow cytometry were used to detect the effect of Herbacetin on the apoptosis in OVA-induced asthma mice model. Additionally, pulmonary pathology was detected by HE and Masson staining, and serum inflammatory factors were detected by alveolar lavage fluid. Herbacetin reduces BESA-2B cells induced by LPS level of inflammation, and reactive oxygen species (ROS) generation, inhibits cell apoptosis, promotes cell proliferation, OVA-induced mice lung histopathology test HE staining, serum inflammatory factors show the same results. Western Blot shows that Herbacetin regulates the expression of Caspase-3, Bax, and Bcl-2. SGK1 overexpression increased the rate of apoptosis, and Herbacetin reversed this phenomenon. By silencing the expression of SGK1, it was found that Herbacetin was an inhibitor of SGK1, which could inhibit the NF-κB/p-P65 pathway in asthmatic airway inflammation. Herbacetin reduces pro-inflammatory cytokine levels by inhibiting the SGK1/NF-κB pathway. Our data suggest that Herbacetin has a significant anti-inflammatory effect on asthma and can be used as a potential therapeutic agent.

Detection and Genomic Characterization of Torque Teno Virus in Pneumoconiosis Patients in China.

Pneumoconiosis is a common occupational disease that can worsen with accompanying infection. Torque teno virus (TTV) is a prevalent human virus with multiple genotypes that can chronically and persistently infect individuals. However, the prevalence of TTV in pneumoconiosis patients is still unclear. This research aims to detect the presence and prevalence of TTV in the alveolar lavage fluid of pneumoconiosis patients in the Hunan Province of China using PCR. As a result, a 65.5% positive rate (19 out of 29) of TTV was detected. The TTV detection rate varies among different stages of silicosis and different pneumoconiosis patient ages. Nine novel TTV genomes ranging in size from 3719 to 3908 nt, named TTV HNPP1, HNPP2, HNPP3, HNPP4, HNPP5, HNPP6-1, HNPP6-2, HNPP7-1 and HNPP7-2, were identified. A genomic comparison and phylogenetic analysis indicated that these nine TTVs represent five different species with high genetic diversity which belong to the genus Alphatorquevirus. HNPP6-1 and HNPP6-2 belong to TTV3, HNPP5 belongs to TTV13, HNPP1 belongs to TTV24, HNPP4 belongs to TTV20, and the others belong to TTV19. The genomes of TTV HNPP1, HNPP6-1, and HNPP6-2 contain three putative open reading frames (ORFs) coding for proteins, ORF1, ORF2, and ORF3, while the other six TTV genomes contain two ORFs coding for proteins, ORF1 and ORF2. These results provide the first description of TTV epidemiology in pneumoconiosis patients in China. The newly identified TTV genome sequences reveal the high genetic diversity of TTV in pneumoconiosis patients and could contribute to a deeper understanding of TTV retention and infection in humans.

Successful management of pneumonia and pyogranulomatous cranial mediastinitis due to Coccidioides species infection with fluconazole in a 3‐year‐old horse

SummaryA 3‐year‐old Quarter Horse gelding originating from Texas presented for fever and inappetence. An encapsulated, mixed echogenic cranial mediastinal mass visible ultrasonographically in the left and right fourth intercostal space that displaced the heart caudally was identified. Histological evaluation of needle biopsies obtained under general anaesthesia revealed a severe pyogranulomatous inflammatory process associated with intralesional round, 15–25 μm in diameter, thick double‐contoured cell wall fungal structures. Sequencing of products obtained from DNA extracted from the paraffin‐embedded biopsy sample and a panfungal PCR assay targeting the large ribosomal unit region had a 99.1% identity to either Coccidioides immitis or C. posadessii. Bronchoscopy revealed purulent exudate in the right primary bronchus. Cytological evaluation of bronchial alveolar lavage fluid (BALF) contained 96% moderately degenerative neutrophils and 4% macrophages. Fungal structures were not appreciated in the BALF. However, the mediastinitis could have resulted from inhalation and dissemination of arthroconidia through lymphatics or directly from the lung parenchyma. Quantitative immunodiffusion of serum for the presence of coccidioidal IgG antibodies yielded a titre of 1:256 suggestive of disseminated coccidioidomycosis. After oral fluconazole for 24 months, the horse's general health and athletic performance had returned to normal and the mediastinal mass was not appreciated sonographically.

Anesthetic management of broncho- alveolar lavage in pulmonary alveolar proteinosis: A case report

: Pulmonary alveolar proteinosis (PAP) is a very rare, life threatening, noninflammatory, diffuse lung disorder characterized by dense accumulation of lipo-proteinaceous material within the alveoli causing hypoxemia, restrictive lung disease leading to respiratory failure. Whole lung lavage (WLL) is considered as the treatment of choice which includes infusing warm saline in the lungs and draining it out with the lipo-porteinaceous materials thereby clearing the obstruction. WLL requires good team co-ordination between the anaesthesiologists, pulmonologists and physiotherapists. The procedural course is challenging in many aspects like hypoxaemia and hemodynamic fluctuations. Post procedure short term mechanical ventilation is commonly required.: A 45 year old female, diagnosed case of PAP presented with dyspnea at rest with increasing oxygen requirement. After clinical examination and investigations, due to severity of the disease, broncho-alveolar lavage (BAL) of left lung was planned with subsequent right lung BAL after few days. During the procedure, desaturation upto 78% was noted. With meticulous corrective measures, saturation picked up and the procedure was completed uneventfully. Post-operatively patient was mechanically ventilated and extubated after 32 hours.: WLL is the treatment of choice for PAP which involves multidisciplinary approach with mulitple challenges. Pre-oxygenation, adequate lung isolation with left sided double lumen tube (DLT), one lung ventilation with positive end expiratory pressure (PEEP), vigilant intra-operative monitoring, cautious use of positional manoeuvres and recruitment manoeuvres with a good teamwork is the key for successful outcome.

An antibacterial, multifunctional nanogel for efficient treatment of neutrophilic asthma

Asthma is a chronic and heterogeneous disease affecting the lungs and respiratory tract. In particular, the neutrophil subtype of asthma was described as persistent, more severe, and corticosteroid-resistant. Growing evidence suggested that nontypeable Haemophilus influenzae (NTHi) infection contributes to the development of neutrophilic asthma, exacerbating clinical symptoms and increasing the associated medical burden. In this work, arginine-grafted chitosan (CS-Arg) was ionically cross-linked with tris(2-carboxyethyl) phosphine (TCEP), and a highly-efficient antimicrobial agent, poly-ε-L-Lysine (ε-PLL), was incorporated to prepare ε-PLL/CS-Arg/TCEP (ECAT) composite nanogels. The results showed that ECAT nanogels exhibited highly effective inhibition against the proliferation of NTHi, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In addition, ECAT nanogels could effectively inhibit the formation of mucins aggregates in vitro, suggesting that the nanogel might have the potential to destroy mucin in respiratory disease. Furthermore, in the ovalbumin (OVA)/NTHi-induced Balb/c mice model of neutrophilic asthma, the number of neutrophils in the alveolar lavage fluid and the percentage of inflammatory cells in the blood were effectively reduced by exposure to tower nebulized administration of ECAT nanogels, and reversing airway hyperresponsiveness (AHR) and reducing inflammation in neutrophilic asthma mice. In conclusion, the construction of ECAT nanogels was a feasible anti-infective and anti-inflammatory therapeutic strategy, which demonstrated strong potential in the clinical treatment of neutrophilic asthma.

Effect of bronchoscopic alveolar lavage combined with methylprednisolone on ALT, LDH, MP-DNA and MP-lgM in children with severe mycoplasma pneumonia.

Effect of bronchoscopic alveolar lavage combined with methylprednisolone on ALT, LDH, MP-DNA and MP-lgM in children with severe mycoplasma pneumonia.

Altered Extracellular Vesicle-Derived Protein and microRNA Signatures in Bronchoalveolar Lavage Fluid from Patients with Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease for which there is no cure. Accumulating research results suggest a role for extracellular vesicles (EVs) in the pathogenesis of COPD. This study aimed to uncover the involvement of EVs and their molecular cargo in the progression of COPD by identification of EV-associated protein and microRNA (miRNA) profiles. We isolated EVs from the bronchial alveolar lavage fluid (BALF) of 18 patients with COPD and 11 healthy controls using size-exclusion chromatography. EV isolates were characterized using nanoparticle tracking analysis and protein content. Proteomic analysis revealed a higher abundance of 284 proteins (log2FC > 1) and a lower abundance of 3 proteins (log2FC < -1) in EVs derived from patients with COPD. Ingenuity pathway analysis showed that proteins enriched in COPD-associated EVs trigger inflammatory responses, including neutrophil degranulation. Variances in surface receptors and ligands associated with COPD EVs suggest a preferential interaction with alveolar cells. Small RNAseq analysis identified a higher abundance of ten miRNAs and a lower abundance of one miRNA in EVs from COPD versus controls (Basemean > 100, FDR < 0.05). Our data indicate that the molecular composition of EVs in the BALF of patients with COPD is altered compared to healthy control EVs. Several components in COPD EVs were identified that may perpetuate inflammation and alveolar tissue destruction.

Disruption of pulmonary microvascular endothelial barrier by dysregulated claudin-8 and claudin-4: uncovered mechanisms in porcine reproductive and respiratory syndrome virus infection

The pulmonary endothelium is a dynamic and metabolically active monolayer of endothelial cells. Dysfunction of the pulmonary endothelial barrier plays a crucial role in the acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), frequently observed in the context of viral pneumonia. Dysregulation of tight junction proteins can lead to the disruption of the endothelial barrier and subsequent leakage. Here, the highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) served as an ideal model for studying ALI and ARDS. The alveolar lavage fluid of pigs infected with HP-PRRSV, and the supernatant of HP-PRRSV infected pulmonary alveolar macrophages were respectively collected to treat the pulmonary microvascular endothelial cells (PMVECs) in Transwell culture system to explore the mechanism of pulmonary microvascular endothelial barrier leakage caused by viral infection. Cytokine screening, addition and blocking experiments revealed that proinflammatory cytokines IL-1β and TNF-α, secreted by HP-PRRSV-infected macrophages, disrupt the pulmonary microvascular endothelial barrier by downregulating claudin-8 and upregulating claudin-4 synergistically. Additionally, three transcription factors interleukin enhancer binding factor 2 (ILF2), general transcription factor III C subunit 2 (GTF3C2), and thyroid hormone receptor-associated protein 3 (THRAP3), were identified to accumulate in the nucleus of PMVECs, regulating the transcription of claudin-8 and claudin-4. Meanwhile, the upregulation of ssc-miR-185 was found to suppress claudin-8 expression via post-transcriptional inhibition. This study not only reveals the molecular mechanisms by which HP-PRRSV infection causes endothelial barrier leakage in acute lung injury, but also provides novel insights into the function and regulation of tight junctions in vascular homeostasis.

Diagnosis of feline pulmonary helminthiasis caused by Aelurostrongylus abstrusus

Pulmonary elurostrongylosis caused by A. abstrusus is widely reported in many countries worldwide. This study describes the detection of elurostrongylosis among domestic cats in Ukraine. Spontaneously infected cats showing signs of lung involvement were selected for the study. The main observed symptom in all animals was either persistent or intermittent coughing. Radiographic findings revealed varying degrees of lung tissue involvement from moderate to extensive, with intensified vascular patterns and clear densification with signs of edema. Morphological blood examinations indicated mild leukocytosis (15.5±1.34 Г/L) and eosinophilia (6.0±0.01%). Fecal examination using the Baermann method detected first-stage A. abstrusus larvae in two out of 47 cats. Bronchoalveolar lavage revealed actively motile first-stage A. abstrusus parasites in 43 out of 47 cats upon microscopic examination. Laboratory results showed higher efficacy of alveolar lavage (48.8%) compared to the Baermann method (17.1%) in parasite detection, emphasizing its significance in diagnosis. Diagnosing A. abstrusus is complicated due to the absence of specific clinical signs and limitations of diagnostic methods. Coproscopic examination methods may yield false-negative results due to low larval concentration and insufficient morphological differentiation from other helminth larvae. Therefore, an integrated approach combining copromicroscopy, blood analysis, and radiographic examinations is crucial for accurate diagnosis. Only with proper diagnosis can a reliable prognosis be formulated and an effective treatment plan(scheme) developed for the patient. Elurostrongylosis should be considered in the differential diagnosis for cats by veterinary practitioners. Further research in Ukraine is necessary for better understanding the epidemiology, risks, and control of A. abstrusus spread among the feline population. Key words: Aelurostrongylus abstrusus, helminths, cats, parasitic diseases, pulmonary helminthiasis, diagnosis.

Sex-biased immunogenicity of a mucosal subunit vaccine against SARS-CoV-2 in mice.

Current vaccines against COVID-19 administered via parenteral route have limited ability to induce mucosal immunity. There is a need for an effective mucosal vaccine to combat SARS-CoV-2 virus replication in the respiratory mucosa. Moreover, sex differences are known to affect systemic antibody responses against vaccines. However, their role in mucosal cellular responses against a vaccine remains unclear and is underappreciated. We evaluated the mucosal immunogenicity of a booster vaccine regimen that is recombinant protein-based and administered intranasally in mice to explore sex differences in mucosal humoral and cellular responses. Our results showed that vaccinated mice elicited strong systemic antibody (Ab), nasal, and bronchiole alveolar lavage (BAL) IgA responses, and local T cell immune responses in the lung in a sex-biased manner irrespective of mouse genetic background. Monocytes, alveolar macrophages, and CD103+ resident dendritic cells (DCs) in the lungs are correlated with robust mucosal Ab and T cell responses induced by the mucosal vaccine. Our findings provide novel insights into optimizing next-generation booster vaccines against SARS-CoV-2 by inducing spike-specific lung T cell responses, as well as optimizing mucosal immunity for other respiratory infections, and a rationale for considering sex differences in future vaccine research and vaccination practice.

Ferruginous components of particulate matters in subway environments, α-Fe2O3 or Fe3O4, exacerbates allergies

The respiratory effects of particulate matter (PM) in subway station platforms or tunnels have attracted considerable research attention. However, no studies have characterized the effects of subway PM on allergic immune responses. In this study, iron oxide (α-Fe2O3 and Fe3O4) particles—the main components of subway PM—were intratracheally administered to BALB/c mice where ovalbumin (OVA) induced allergic pulmonary inflammation. Iron oxide particles enhanced OVA-induced eosinophil recruitment around the bronchi and mucus production from airway epithelium. The concentrations of type 2 cytokines, namely, interleukin (IL)-5 and IL-13, in bronchial alveolar lavage fluids were increased by iron oxide particles. Iron oxide particles also increased the number of type 2 innate lymphoid cells and CD86+ cells in the lung. Moreover, phagocytosis of particles in lung cells was confirmed by Raman spectroscopy. In a subsequent in vitro study, bone marrow-derived antigen-presenting cells (APCs) isolated from NC/Nga mice were exposed to iron oxide particles and OVA. They were also exposed to outdoor ambient PM: Vehicle Exhaust Particulates (VEP) and Urban Aerosols (UA) as references. Iron oxide particles promoted the release of lactate dehydrogenase, C-X-C motif chemokine ligand 1 and IL-1α from APCs, which tended to be stronger than those of VEP. These results suggest that iron oxide particles enhance antigen presentation in the lungs, promoting allergic immune response in mice; iron oxide particles-induced death and inflammatory response of APCs can contribute to allergy exacerbation. Although iron oxide particles do not contain various compounds like VEP, iron oxide alone may have sufficient influence.

The STAT3 inhibitor B9 alleviates lipopolysaccharide-induced acute lung injury through its anti-inflammatory effects

The development of acute lung injury (ALI), a common respiratory condition with multiple causes, is significantly influenced by the pro-inflammatory environment of signal transducer and activator of transcription 3 (STAT3) in macrophages. Our study aimed to evaluate the anti-inflammatory effects of B9 (N-(4-hydroxyphenyl)-9, 10-dioxo-9, 10-dihydroanthracene-2-sulfonamide), a novel inhibitor targeting the STAT3 SH2 domain, in macrophages and to assess its therapeutic potential for ALI using a mouse model of lipopolysaccharide (LPS)-induced ALI. We found that B9 (30 mg/kg) significantly reduced lung pathological damage and neutrophil infiltration caused by the intratracheal administration of LPS. Additionally, the high expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in alveolar lavage fluid was also inhibited by B9 treatment. The decreased expression of CD86 and increased CD206 in lung tissue demonstrated the anti-inflammatory effect of B9, which was due to its inhibition of the STAT3 signaling pathway in macrophages of ALI mice. Furthermore, B9 suppressed the activation of RAW264.7 cells induced by LPS, characterized by its ability to inhibit the activation of iNOS and STAT3 in a dose-dependent manner, as well as reduce the secretion of IL-6 and IL-1β. The in vivo preliminary safety evaluation indicated that B9 had a favorable safety profile at the administered doses. These results suggest that B9 exerts a therapeutic effect on LPS-induced ALI, potentially by preventing the phosphorylation of STAT3 Y705 and S727 without affecting the STAT3 protein level. Taken together, these findings provide a foundation for developing B9 as a novel anti-inflammatory agent for ameliorating LPS-induced ALI.

Clinical characteristics and risk factors for bacterial co-infections in COVID-19 patients: A retrospective study

ObjectiveThis study aimed to analyse the bacterial composition, distribution, drug sensitivity, and clinical characteristics of patients with coronavirus disease 2019 (COVID-19) who develop bacterial co-infections. MethodsWe conducted a retrospective study of 184 patients with COVID-19 admitted between December 2022 and January 2023. Data on gender, age, length of hospital stay, pneumonia classification, underlying diseases, invasive surgery, hormone therapy, inflammation indicators, and other relevant information were collected. Samples of sputum, bronchoscopy sputum, alveolar lavage fluid, middle urine, puncture fluid, wound secretions, and blood were collected for pathogen isolation, identification, and drug sensitivity testing. ResultsThe majority of patients with COVID-19 with bacterial co-infection were elderly and had underlying diseases. Invasive surgery and hormone therapy were identified as risk factors for co-infections. Laboratory analysis showed reduced lymphocyte counts and elevated levels of C-reactive protein and procalcitonin. The most common pathogens in co-infections were Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. The detection rate of drug-resistant strains, including methicillin-resistant S. aureus, carbapenem-resistant K. pneumoniae, carbapenem-resistant A. baumannii, carbapenem-resistant P. aeruginosa, and carbapenem-resistant E. coli, increased with the severity of pneumonia. ConclusionRespiratory tract infections were the most common site of bacterial co-infection in patients with COVID-19. Severe cases were more susceptible to multidrug-resistant pathogens, leading to a higher mortality rate. Timely control and prevention of co-infection are crucial for improving the prognosis of patients with COVID-19.

Metagenomic next-generation sequencing-based retrospective investigation of the drug resistance sites of Mycoplasma pneumoniae in children

Objective: To analyze the drug-resistant gene loci of Mycoplasma pneumoniae (MP) using metagenomic next-generation sequencing (mNGS). Methods: From November 2022 to October 2023, 697 clinical samples (including sputum, alveolar lavage fluid and blood) of 686 children with Mycoplasma pneumoniae positive detected by mNGS were retrospectively analyzed. Samples were divided into intensive care unit (ICU) group and non-ICU group, Chi-square test was used to compare groups, and Mann-Kendall trend test was used to analyze the change trend of the detection rate of drug resistance gene loci over time. Results: Of the 697 samples, 164 were from the ICU group and 533 were from the non-ICU group. The detection rate of Mycoplasma pneumoniae resistance gene was 44.3% (309/697), and all detected drug-resistant gene loci of MP were A2063G. The detection rate of Mycoplasma pneumoniae in ICU group was 50.0% (82/164), and the detection rates of Mycoplasma pneumoniae resistance gene loci in sputum, alveolus lavage fluid and blood samples were 75.0% (18/24) and 48.4% (62/128), respectively. The detection rate in sputum was higher than alveolus lavage fluid samples (χ2=5.72,P=0.017). The detection rate of Mycoplasma pneumoniae in non-ICU group was 42.6% (227/533), the detection rate of Mycoplasma pneumoniae resistance gene loci in sputum and alveolar lavage fluid was 40.0% (16/40), 44.3% (201/454), and no detection rate in blood samples (0/12). There was no significant difference in the detection rate of alveolar lavage fluid and sputum (χ2=0.27, P=0.602). From November 2022 to October 2023, the detection rate of submitted samples showed an increasing trend month by month (overall: Z=3.99, ICU inspection group: Z=2.93, non-ICU group: Z=3.01, all P<0.01). Among the bacteria commonly detected with Mycoplasma pneumoniae, Streptococcus pneumoniae accounted for the highest proportion, the detection rate was 15.5% (108/697), and Epstein-Barr virus accounted for the highest proportion of 17.6% (123/697). Conclusions: From November 2022 to October 2023, the detection rate of Mycoplasma pneumoniae drug resistance gene loci showed an increasing trend. The detection rate of drug resistance gene loci in sputum samples of ICU group was higher than alveolus lavage fluid. No new drug resistance site were detected.

Sex-biased immunogenicity of a mucosal subunit vaccine against SARS-CoV-2 in mice

Abstract Current vaccines against COVID-19 administered via parenteral route have limited ability to induce mucosal immunity. There is a need for an effective mucosal vaccine to combat SARS-CoV-2 virus replication in the respiratory mucosa. Moreover, sex differences are known to affect systemic antibody responses against vaccines. However, their role in mucosal cellular responses against a vaccine remains unclear and is underappreciated. We evaluated the mucosal immunogenicity of a booster vaccine regimen that is recombinant protein-based and administered intranasally in mice to explore sex differences in mucosal humoral and cellular responses. Our results showed that vaccinated mice elicited strong systemic antibody (Ab), nasal, and bronchiole alveolar lavage (BAL) IgA responses, and local T cell immune responses in the lung in a sex-biased manner irrespective of mouse genetic background. Monocytes, alveolar macrophages, and CD103+ resident dendritic cells in the lungs are correlated with robust mucosal Ab and T cell responses induced by the mucosal vaccine. Our findings provide novel insights into optimizing next-generation booster vaccines against SARS-CoV-2 by inducing spike-specific lung T cell responses, and a rationale for considering biological sex differences in future vaccine research and vaccination practice.