Size matters: Aerobic methane oxidation in sediments of shallow thermokarst lakes.

Shallow thermokarst lakes are important sources of greenhouse gases (GHGs) such as methane (CH4 ) and carbon dioxide (CO2 ) resulting from continuous permafrost thawing due to global warming. Concentrations of GHGs dissolved in water typically increase with decreasing lake size due to coastal abrasion and organic matter delivery. We hypothesized that (i) CH4 oxidation depends on the natural oxygenation gradient in the lake water and sediments and increases with lake size because of stronger wind-induced water mixing; (ii) CO2 production increases with decreasing lake size, following the dissolved organic matter gradient; and (iii) both processes are more intensive in the upper than deeper sediments due to the in situ gradients of oxygen (O2 ) and bioavailable carbon. We estimated aerobic CH4 oxidation potentials and CO2 production based on the injection of 13 C-labeled CH4 in the 0-10 cm and 10-20 cm sediment depths of small (~300 m2 ), medium (~3000 m2 ), and large (~106 m2 ) shallow thermokarst lakes in the West Siberian Lowland. The CO2 production was 1.4-3.5 times stronger in the upper sediments than in the 10-20 cm depth and increased from large (158 ± 18 nmol CO2 g-1 sediment d.w. h-1 ) to medium and small (192 ± 17 nmol CO2 g-1 h-1 ) lakes. Methane oxidation in the upper sediments was similar in all lakes, while at depth, large lakes had 14- and 74-fold faster oxidation rates (5.1 ± 0.5 nmol CH4 -derived CO2 g-1 h-1 ) than small and medium lakes, respectively. This was attributed to the higher O2 concentration in large lakes due to the more intense wind-induced water turbulence and mixing than in smaller lakes. From a global perspective, the CH4 oxidation potential confirms the key role of thermokarst lakes as an important hotspot for GHG emissions, which increase with the decreasing lake size.

The spatial distribution of rhizosphere microbial activities under drought: water availability is more important than root-hair-controlled exudation.

Root hairs and soil water content are crucial in controlling the release and diffusion of root exudates and shaping profiles of biochemical properties in the rhizosphere. But whether root hairs can offset the negative impacts of drought on microbial activity remains unknown. Soil zymography, 14 C imaging and neutron radiography were combined to identify how root hairs and soil moisture affect rhizosphere biochemical properties. To achieve this, we cultivated two maize genotypes (wild-type and root-hair-defective rth3 mutant) under ambient and drought conditions. Root hairs and optimal soil moisture increased hotspot area, rhizosphere extent and kinetic parameters (Vmax and Km ) of ß-glucosidase activities. Drought enlarged the rhizosphere extent of root exudates and water content. Colocalization analysis showed that enzymatic hotspots were more colocalized with root exudate hotspots under optimal moisture, whereas they showed higher dependency on water hotspots when soil water and carbon were scarce. We conclude that root hairs are essential in adapting rhizosphere properties under drought to maintain plant nutrition when a continuous mass flow of water transporting nutrients to the root is interrupted. In the rhizosphere, soil water was more important than root exudates for hydrolytic enzyme activities under water and carbon colimitation.

Temperature sensitivity of anaerobic methane oxidation versus methanogenesis in paddy soil: Implications for the CH4 balance under global warming.

The global methane (CH4 ) budget is based on a sensitive balance between methanogenesis and CH4 oxidation (aerobic and anaerobic). The response of these processes to climate warming, however, is not quantified. This largely reflects our lack of knowledge about the temperature sensitivity (Q10 ) of the anaerobic oxidation of CH4 (AOM)-a ubiquitous process in soils. Based on a 13 CH4 labeling experiment, we determined the rate, Q10 and activation energy of AOM and of methanogenesis in a paddy soil at three temperatures (5, 20, 35°C). The rates of AOM and of methanogenesis increased exponentially with temperature, whereby the AOM rate was significantly lower than methanogenesis. Both the activation energy and Q10 of AOM dropped significantly from 5-20 to 20-35°C, indicating that AOM is a highly temperature-dependent microbial process. Nonetheless, the Q10 of AOM and of methanogenesis were similar at 5-35°C, implying a comparable temperature dependence of AOM and methanogenesis in paddy soil. The continuous increase of AOM Q10 over the 28-day experiment reflects the successive utilization of electron acceptors according to their thermodynamic efficiency. The basic constant for Q10 of AOM was calculated to be 0.1 units for each 3.2 kJ mol-1 increase of activation energy. We estimate the AOM in paddy soils to consume 2.2~5.5 Tg CH4 per year on a global scale. Considering these results in conjunction with literature data, the terrestrial AOM in total consumes ~30% of overall CH4 production. Our data corroborate a similar Q10 of AOM and methanogenesis. As the rate of AOM in paddy soils is lower than methanogenesis, however, it will not fully compensate for an increased methane production under climate warming.

Visualization and quantification of carbon "rusty sink" by rice root iron plaque: Mechanisms, functions, and global implications.

Paddies contain 78% higher organic carbon (C) stocks than adjacent upland soils, and iron (Fe) plaque formation on rice roots is one of the mechanisms that traps C. The process sequence, extent and global relevance of this C stabilization mechanism under oxic/anoxic conditions remains unclear. We quantified and localized the contribution of Fe plaque to organic matter stabilization in a microoxic area (rice rhizosphere) and evaluated roles of this C trap for global C sequestration in paddy soils. Visualization and localization of pH by imaging with planar optodes, enzyme activities by zymography, and root exudation by 14 C imaging, as well as upscale modeling enabled linkage of three groups of rhizosphere processes that are responsible for C stabilization from the micro- (root) to the macro- (ecosystem) levels. The 14 C activity in soil (reflecting stabilization of rhizodeposits) with Fe2+ addition was 1.4-1.5 times higher than that in the control and phosphate addition soils. Perfect co-localization of the hotspots of ß-glucosidase activity (by zymography) with root exudation (14 C) showed that labile C and high enzyme activities were localized within Fe plaques. Fe2+ addition to soil and its microbial oxidation to Fe3+ by radial oxygen release from rice roots increased Fe plaque (Fe3+ ) formation by 1.7-2.5 times. The C amounts trapped by Fe plaque increased by 1.1 times after Fe2+ addition. Therefore, Fe plaque formed from amorphous and complex Fe (oxyhydr)oxides on the root surface act as a "rusty sink" for organic matter. Considering the area of coverage of paddy soils globally, upscaling by model revealed the radial oxygen loss from roots and bacterial Fe oxidation may trap up to 130 Mg C in Fe plaques per rice season. This represents an important annual surplus of new and stable C to the existing C pool under long-term rice cropping.

Twenty-four-week interim outcomes of bedaquiline-containing regimens in treatment of adolescents with rifampicin-resistant tuberculosis: A retrospective cohort study in China.

AIM: To evaluate the 24-week interim outcomes of bedaquiline-containing regimens in the treatment of adolescents with rifampicin-resistant tuberculosis (RR-TB) in China. METHODS: Adolescents with RR-TB from two hospitals were included in this retrospective study. All patients received the longer regimen containing bedaquiline. Sputum culture, chest computed tomography, blood tests and electrocardiography were performed regularly, and the outcomes after 24 weeks of treatment were reported. RESULTS: Four male and six female adolescents aged 11 to 17 years old were included. Among them, four (40.0%), four (40.0%) and two (20.0%) were confirmed to have RR-TB, multidrug-resistant TB and extensively drug-resistant TB, respectively. The most common companion drugs included linezolid (100.0%), cycloserine (90.0%), pyrazinamide (80.0%), moxifloxacin (50.0%) and levofloxacin (40.0%). Culture conversion rates of 80.0%, 100.0% and 100.0% were observed at weeks 2, 4 and 24, respectively. The mean maximum drug concentration of bedaquiline at weeks 2, 12 and 24 was 3.29 ± 0.66, 1.78 ± 0.81 and 1.93 ± 0.74 µg/mL, respectively. Six adverse events including leukopenia (50.0%), Fridericia-corrected QT (QTcF) interval prolongation (16.7%), anaemia (16.7%) and peripheral neuropathy (16.7%) were observed in five (50.0%) patients. No patient discontinued bedaquiline owing to QTcF interval prolongation. Meanwhile, no deaths, reversions or serious adverse events were reported during 24 weeks of treatment. CONCLUSION: A longer regimen containing bedaquiline was effective and well tolerated in Chinese adolescents with RR-TB. The combination of bedaquiline and linezolid may be a favourable choice for this population.

Anti-IL-23 exerted protective effects on cerebral ischemia-reperfusion injury through JAK2/STAT3 signaling pathway.

Ischemia-reperfusion frequently occurs in ischemic cerebral vascular disease, during which the inflammatory signaling plays essential roles. The aim of this study was to discover the efficacy of the antibody to a key immune cytokine IL-23 (anti-IL-23) for the therapy of cerebral ischemia-reperfusion injury. We established the cerebral ischemia-reperfusion injury model by middle cerebral artery occlusion (MCAO). Anti-IL-23 injection attenuated lesions indicated by histology study. RT-PCR and Western blot were employed to detect the mRNA and protein expression of JAK2 and STAT3 after anti-IL-23 treatment. ELISA was utilized to measure the levels of MDA (malondialdehyde) and superoxide dismutase (SOD). Moreover, curcumin and IL-6 were implicated in the endogenous intervention of IL-23 signaling in vivo. Our data demonstrated that the treatment of anti-IL-23 might transcriptionally activate the classic immune pathway in the brain. Anti-IL-23 augmented phosphorylation levels of both JAK2 and STAT3, suggesting the amplification signaling of JAK/STAT after exogenous IL-23 intervention. Anti-IL-23 reduced ROS molecules of STAT downstream in the serum and brain. It also alleviated the injury by bringing down levels of MDA and SOD in the serum. JAK2 inhibitor could abolish the effect of anti-IL-23 whereas JAK3 ameliorated the injury. The combination of anti-IL-23 and JAK3i could reduce infarct volume more effectively. In summary, this study indicated that anti-IL-23 had protective effects against cerebral ischemia-reperfusion injury by targeting the immune specific JAK2-STAT3 in JAK/STAT pathway.

Corticosteroids alleviate lipopolysaccharide-induced inflammation and lung injury via inhibiting NLRP3-inflammasome activation.

The role of corticosteroids in acute lung injury (ALI) remains uncertain. This study aims to determine the underlying mechanisms of corticosteroid treatment for lipopolysaccharide (LPS)-induced inflammation and ALI. We used corticosteroid treatment for LPS-induced murine ALI model to investigate the effect of corticosteroid on ALI in vivo. Moreover, LPS-stimulated macrophages were used to explore the specific anti-inflammatory effects of corticosteroids on NLRP3-inflammasome in vitro. We found corticosteroids attenuated LPS-induced ALI, which manifested in reduction of the alveolar structure destruction, the infiltration of neutrophils and the inflammatory cytokines release of interleukin-1ß (IL-1ß) and interleukin-18 (IL-18) in Lung. In vitro, when NLRP3-inflammasome was knocked out, inflammatory response of caspase-1 activation and IL-1ß secretion was obviously declined. Further exploration, our results showed that when corticosteroid preprocessed macrophages before LPS primed, it obviously inhibited the activation of caspase-1 and the maturation of IL-1ß, which depended on inhibiting the nuclear factor-κB (NF-κB) signal pathway activation. However, when corticosteroids intervened the LPS-primed macrophages, it also negatively regulated NLRP3-inflammasome activation through suppressing mitochondrial reactive oxygen species (mtROS) production. Our results revealed that corticosteroids played a protection role in LPS-induced inflammation and ALI by suppressing both NF-κB signal pathway and mtROS-dependent NLRP3 inflammasome activation.

Macrolides protect against Pseudomonas aeruginosa infection via inhibition of inflammasomes.

Macrolides antibiotics have been effectively used in many chronic diseases, especially with Pseudomonas aeruginosa (P. aeruginosa) infection. The mechanisms underlying the therapeutic effects of macrolides in these diseases remain poorly understood. We established a mouse model of chronic lung infection using P. aeruginosa agar-beads, with azithromycin treatment or placebo. Lung injury, bacterial clearance, and inflammasome-related proteins were measured. In vitro, the inflammasomes activation induced by flagellin or ATP were assessed in LPS-primed macrophages with or without macrolides treatment. Plasma IL-18 levels were determined from patients who were diagnosed with bronchiectasis isolated with or without P. aeruginosa and treated with azithromycin for 3-5 days. Azithromycin treatment enhanced bacterial clearance and attenuated lung injury in mice chronically infected with P. aeruginosa, which resulted from the inhibition of caspase-1-dependent IL-1ß and IL-18 secretion. In vitro, azithromycin and erythromycin inhibited NLRC4 and NLRP3 inflammasomes activation. Plasma IL-18 levels were higher in bronchiectasis patients with P. aeruginosa isolation compared with healthy controls. Azithromycin administration markedly decreased IL-18 secretion in bronchiectasis patients. The results of this study reveal that azithromycin and erythromycin exert a novel anti-inflammatory effect by attenuating inflammasomes activation, which suggests potential treatment options for inflammasome-related diseases.

Analysis of Microarray-Identified Genes and MicroRNAs Associated with Idiopathic Pulmonary Fibrosis.

The aim of this study was to identify potential microRNAs and genes associated with idiopathic pulmonary fibrosis (IPF) through web-available microarrays. The microRNA microarray dataset GSE32538 and the mRNA datasets GSE32537, GSE53845, and GSE10667 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed miRNAs (DE-miRNAs)/genes (DEGs) were screened with GEO2R, and their associations with IPF were analyzed by comprehensive bioinformatic analyses. A total of 45 DE-microRNAs were identified between IPF and control tissues, whereas 67 common DEGs were determined to exhibit the same expression trends in all three microarrays. Furthermore, functional analysis indicated that microRNAs in cancer and ECM-receptor interaction were the most significant pathways and were enriched by the 45 DE-miRNAs and 67 common DEGs. Finally, we predicted potential microRNA-target interactions between 17 DE-miRNAs and 17 DEGs by using at least three online programs. A microRNA-mediated regulatory network among the DE-miRNAs and DEGs was constructed that might shed new light on potential biomarkers for the prediction of IPF progression.

Effects of long-term use of macrolides in patients with non-cystic fibrosis bronchiectasis: a meta-analysis of randomized controlled trials.

BACKGROUND: The purpose of this study was to evaluate the clinical benefits and safety of the long-term use of macrolides in patients with non-cystic fibrosis (non-CF) bronchiectasis. METHODS: Embase, Pubmed, the Cochrane Library and Web of Science databases were searched from inception up to March 2014. The primary outcome was the improvement of exacerbations of bronchiectasis. Secondary endpoints included changes of microbiology, lung function, quality of life, sputum volume, adverse events and macrolide resistance. RESULTS: The literature search yielded 139 studies, ten of which containing 601 patients were included in this meta-analysis. Macrolides showed a statistically-significant improvement in reducing acute exacerbations per patient during follow-up treatment (RR = 0.55, 95% CI: 0.47, 0.64, P < 0.001), increasing the number of patients free from exacerbations (OR = 2.81, 95% CI: 1.85, 4.26, P < 0.001), and prolonging time to a first exacerbation (HR = 0.38, 95% CI: 0.28, 0.53, P < 0.001). Macrolides maintenance treatment was superior to control with respect to attenuating FEV1 decline (p = 0.02), improving sputum volume (p = 0.009) and SGRQ total scores (p = 0.02), but showed a higher risk of adverse events, especially diarrhea (OR = 5.36; 95% CI: 2.06, 13.98, P = 0.0006). Eradication of pathogens was improved in the macrolide group (OR = 1.76, 95% CI: 0.91, 3.41, P = 0.09), while pathogen resistance caused by macrolides dramatically increased (OR = 16.83, 95% CI: 7.26, 38.99, P < 0.001). The new appearance of a microbiologic profile or participant withdrawal due to adverse events showed no significant differences between the two groups. CONCLUSION: In patients with non-CF bronchiectasis, macrolide maintenance treatment can effectively reduce frequency of exacerbations, attenuate lung function decline, decrease sputum volume, improve quality of life, but may be accompanied with increased adverse events (especially diarrhea) and pathogen resistance.

Pathogen characteristics reveal novel antibacterial approaches for interstitial lung disease.

Interstitial lung disease (ILD) is a clinical disorder associated with changes of lung structure. Concurrent infection is a serious complication and one of the major factors that exacerbates ILD. Pathogen screening is a critical step in early diagnosis and proper treatment of ILD with secondary infection. Here we analyzed distribution and drug susceptibility of pathogens isolated from hospitalized ILD patients from January, 2007 to December, 2008 and compared them to bacterial drug resistance data in CHINET during the same period. The main specimens were from sputum culture, lavage fluid culture, lung biopsy tissue culture, and pleural effusion culture and bacterial or fungal cultures were performed on these specimens accordingly. Drug susceptibility was tested for positive bacterial cultures using disk diffusion (Kirby-Bauer method) and E Test strips in which results were determined based on the criteria of CLSI (2007). A total of 371 pathogen strains from ILD patients, including 306 bacterial strains and 65 fungal strains were isolated and cultured. Five main bacterial strains and their distribution were as follows: Klebsiella pneumoniae (31.7%), Pseudomonas aeruginosa (20.6%), Acinetobacter (12.7%), Enterobacter cloacae (8.2%), and Staphylococcus aureus (7.8%). The results showed that ILD patients who had anti-infection treatment tended to have Gram-negative bacteria, whether they acquired an infection in the hospital or elsewhere. Drug resistance screening indicated that aminoglycosides and carbapenems had lower antibiotic resistance rates. In addition, we found that the usage of immunosuppressants was associated with the increased infection rate and number of pathogens that were isolated. In conclusion, aminoglycosides and carbapenems may be selected as a priority for secondary infection to control ILD progression. Meanwhile, the use of anti-MRSA/MRCNS drugs may be considered for Staphylococcus infection.

Acidification of European croplands by nitrogen fertilization: Consequences for carbonate losses, and soil health.

Soil acidification is an ongoing problem in intensively cultivated croplands due to inefficient and excessive nitrogen (N) fertilization. We collected high-resolution data comprising 19,969 topsoil (0-20 cm) samples from the Land Use and Coverage Area frame Survey (LUCAS) of the European commission in 2009 to assess the impact of N fertilization on buffering substances such as carbonates and base cations. We have only considered the impacts of mineral fertilizers from the total added N, and a N use efficiency of 60 %. Nitrogen fertilization adds annually 6.1 × 107 kmol H+ to European croplands, leading to annual loss of 6.1 × 109 kg CaCO3. Assuming similar acidification during the next 50 years, soil carbonates will be completely removed from 3.4 × 106 ha of European croplands. In carbonate-free soils, annual loss of 2.1 × 107 kmol of basic cations will lead to strong acidification of at least 2.6 million ha of European croplands within the next 50 years. Inorganic carbon and basic cation losses at such rapid scale tremendously drop the nutrient status and production potential of croplands. Soil liming to ameliorate acidity increases pH only temporarily and with additional financial and environmental costs. Only the direct loss of soil carbonate stocks and compensation of carbonate-related CO2 correspond to about 1.5 % of the proposed budget of the European commission for 2023. Thus, controlling and decreasing soil acidification is crucial to avoid degradation of agricultural soils, which can be done by adopting best management practices and increasing nutrient use efficiency. Regular screening or monitoring of carbonate and base cations contents, especially for soils, where the carbonate stocks are at critical levels, are urgently necessary.

Efficacy and safety of the all-oral bedaquiline-containing regimen as treatment for pediatric multidrug/rifampicin-resistant tuberculosis: a multicenter, retrospective, cohort study.

OBJECTIVE: The study aimed to observe the efficacy and safety of an all-oral bedaquiline (BDQ)-containing regimen for pediatric multidrug/rifampicin-resistant tuberculosis (MDR/RR-TB) through a multicenter, retrospective study in China. METHODS: In the study, pediatric patients receiving all-oral BDQ-containing regimen (BDQ group) with clinical matched control group were included, the control group received an injection-containing regimen. The treatment outcomes and the incidence of adverse events (AEs) were compared and analyzed. RESULTS: 79 pediatric patients were enrolled, including 37 cases in BDQ group and 42 cases in the control group, the median age was 12 {8-16} and 11 {9-15} in both groups respectively. Favorable treatment outcome and cure rate in BDQ group were significantly higher than those in control group (100%vs 83.3%, p 0.03; 94.6%vs 63.3%, p 0.00). Median time of sputum culture conversion in BDQ group was significantly shorter than that in the control group (4 weeks vs 8 weeks, p 0.00). The incidence of AEs in the BDQ group was significantly less than that in the control group (48.6% vs 71.4%, p 0.03). No AEs leading to treatment discontinuation of BDQ occurred. CONCLUSIONS: The all-oral BDQ-containing regimens may be effective and safe in the Chinese pediatric population.

Bioinformatics analysis-based mining of potential markers for inflammatory bowel disease and their immune relevance.

Background: The incidence of inflammatory bowel disease (IBD) is increasing every year and is characterized by a prolonged course, frequent relapses, difficulty in curing, and a lack of more efficacious therapeutic biomarkers. The aim of this study was to find key core genes as therapeutic biomarkers for IBD. Methods: GSE75214 in Gene Expression Omnibus (GEO) was used as the experimental set. The genes in the top 25% of standard deviation of all samples in the experimental set were subjected to systematic weighted gene co-expression network analysis (WGCNA) to find candidate genes. Then, least absolute shrinkage and selection operator (LASSO) logistic regression was used to further screen the central genes. Finally, the validity of hub genes was verified on GEO dataset GSE179285 using "BiocManager" R package. Results: Twelve well-preserved modules were identified in the experimental set using the WGCNA method. Among them, five modules significantly associated with IBD were screened as clinically significant modules, and four candidate genes were screened from these five modules. Then TIMP1, GUCA2B, and HIF1A were screened as hub genes. These hub genes successfully distinguished tumor samples from healthy tissues by artificial neural network algorithm in an independent test set with an area under the working characteristic curve of 0.946 for the subjects. Conclusions: IBD differentially expressed gene (DEGs) are involved in immunoregulatory processes. TIMP1, GUCA2B, and HIF1A, as core genes of IBD, have the potential to be therapeutic targets for patients with IBD, and our findings may provide a new outlook on the future treatment of IBD.

Discovery and analysis of the relationship between organic components in exhaled breath and bronchiectasis.

The prevalence of patients with bronchiectasis (BE) has been rising in recent years, which increases the substantial burden on the family and society. Exploring a convenient, effective, and low-cost screening tool for the diagnosis of BE is urgent. We expect to identify the accuracy (ACC) of breath biomarkers (BBs) for the diagnosis of BE through breathomics testing and explore the association between BBs and clinical features of BE. Exhaled breath samples were collected and detected by high-pressure photon ionization time-of-flight mass spectrometry in a cross-sectional study. Exhaled breath samples were from 215 patients with BE and 295 control individuals. The potential BBs were selected via the machine learning (ML) method. The overall performance was assessed for the BBs-based BE detection model. The significant BBs between different subgroups such as the severity of BE, acute or stable stage, combined with hemoptysis or not, with or without nontuberculous mycobacterium (NTM),P. aeruginosa(P.a) isolation or not, and the BBs related to the number of involved lung lobes and lung function were discovered and analyzed. The top ten BBs based ML model achieved an area under the curve of 0.940, sensitivity of 90.7%, specificity of 85%, and ACC of 87.4% in BE diagnosis. Except for the top ten BBs, other BBs were found also related to the severity, acute/stable status, hemoptysis or not, NTM infection,P.aisolation, the number of involved lobes, and three lung functional parameters in BE patients. BBs-based BE detection model showed good ACC for diagnosis. BBs have a close relationship with the clinical features of BE. The breath test method may provide a new strategy for BE screening and personalized management.

Analysis of Drug-Resistant Tuberculosis in Children in Shenyang, China, 2017-2021.

Objective: Drug-resistant tuberculosis (DR-TB) in children seriously threatens TB control. Information on the epidemiology and characteristics of DR-TB in children in China is limited. We studied data in Shenyang Tenth People's Hospital to understand the DR-TB epidemiology in children in Shenyang. Design or Methods: We retrospectively analyzed drug resistance testing data of pediatric TB patients between 2017 and 2021, and included 2976 clinically-diagnosed pediatric TB patients. We described the epidemiology of DR-TB and analyzed the trends of DR-TB incidence. The Kappa value was calculated to assess the agreement between MGIT 960 DST and Xpert MTB/RIF for detecting rifampicin resistance. Multivariate logistic regression was used to identify the risk factors for DR-TB in pediatric patients. Results: Of the 2976 TB patients, 1076 were confirmed by MGIT 960 culture and/or Xpert MTB/RIF. Among the 806 patients identified by MGIT 960 culture, 232 cases (28.78%) were DR-TB. Resistance to the six drugs was in the following order: streptomycin (21.09%), isoniazid (9.35%), rifampin (15.01%), levofloxacin (6.20%), ethambutol (4.22%), and amikacin (3.23%). Alarmingly, 12.90% were MDR-TB (104/806), including 28 (3.47%) pre-XDR-TB. Of the 1076 pediatric TB patients, 295 (27.4%) developed DR-TB to any one drug (including 69 rifampicin-resistant cases identified by Xpert MTB/RIF only). No difference was found in the incidence of pediatric DR-TB between 2017 and 2021. Among 376 patients who were positive for both methods, using the MGIT 960 DST results as the gold standard, Xpert MTB/RIF's sensitivity for detecting rifampicin resistance was 91.38% and its specificity was 94.65%. Conclusion: Between 2017 and 2021, the DR-TB incidence in children remained unchanged in Shenyang. RR-TB, MDR-TB, and even Pre-XDR-TB require attention in children with drug-resistant TB. Xpert MTB/RIF helped to detect more rifampicin-resistant pediatric patients; thus Xpert MTB/RIF should be widely used as an important complementary tool to detect rifampicin-resistant TB in children.

Alveolar type II epithelial cell FASN maintains lipid homeostasis in experimental COPD.

Alveolar epithelial type II (AEC2) cells strictly regulate lipid metabolism to maintain surfactant synthesis. Loss of AEC2 cell function and surfactant production are implicated in the pathogenesis of the smoking-related lung disease chronic obstructive pulmonary disease (COPD). Whether smoking alters lipid synthesis in AEC2 cells and whether altering lipid metabolism in AEC2 cells contributes to COPD development are unclear. In this study, high-throughput lipidomic analysis revealed increased lipid biosynthesis in AEC2 cells isolated from mice chronically exposed to cigarette smoke (CS). Mice with a targeted deletion of the de novo lipogenesis enzyme, fatty acid synthase (FASN), in AEC2 cells (FasniΔAEC2) exposed to CS exhibited higher bronchoalveolar lavage fluid (BALF) neutrophils, higher BALF protein, and more severe airspace enlargement. FasniΔAEC2 mice exposed to CS had lower levels of key surfactant phospholipids but higher levels of BALF ether phospholipids, sphingomyelins, and polyunsaturated fatty acid-containing phospholipids, as well as increased BALF surface tension. FasniΔAEC2 mice exposed to CS also had higher levels of protective ferroptosis markers in the lung. These data suggest that AEC2 cell FASN modulates the response of the lung to smoke by regulating the composition of the surfactant phospholipidome.

Advantages and challenges of metagenomic sequencing for the diagnosis of pulmonary infectious diseases.

OBJECTIVE: We aim to familiarize the application status of metagenomic sequencing in diagnosing pulmonary infections, to compare metagenomic sequencing with traditional diagnostic methods, to conclude the advantages and limitations of metagenomic sequencing, and to provide some advice for clinical practice and some inspiration for associated researches. DATA SOURCES: The data were obtained from peer-reviewed literature, white papers, and meeting reports. RESULTS: This review focused on the applications of untargeted metagenomic sequencing in lungs infected by bacteria, viruses, fungi, chlamydia pneumoniae, Mycoplasma pneumoniae, parasites, and other pathogens. Compared with conventional diagnostic methods, metagenomic sequencing is better in detecting novel, rare, and unexpected pathogens and being applied in co-infections. Meanwhile, it can also provide more comprehensive information about pathogens. However, metagenomic sequencing still has limitations. Also, the situations that should be applied in and how the results should be interpreted are discussed in this review. CONCLUSION: Metagenomic sequencing improves efficiency to identify pathogens compared with traditional diagnostic methods and can be applied in clinical diagnosis. However, the technology of metagenomic sequencing still needs to be improved. Also, clinicians should learn more about when to use metagenomic sequencing and how to interpret its results.

Performance of TB-LAMP in the Diagnosis of Tuberculous Empyema Using Samples Obtained From Pleural Decortication.

Purpose: To evaluate the performance of TB-LAMP in the diagnosis of TB empyema using pleural tissue specimens obtained during pleural decortication. Methods: Using the clinical records and the different diagnostic test results of patients who underwent pleural decortication in a TB-designated hospital over 3.5 years, we calculated the sensitivity, specificity positive predictive, and negative predictive values of the pathology, MGIT 960 culture, and TB-LAMP obtained by using pleural tissue specimens against the etiologic diagnosis and composite clinical reference standard (CCRS) as the reference standards. Result: A total of 304 patients' records were extracted. All these patients had gone through pleural decortication. When the etiologic diagnosis was used as the reference, the sensitivity of TB-LAMP in identifying TB empyema was 77.8% (compared to 10.6% of MGIT 960 P < 0.05). The sensitivity of MGIT 960, pathology, and TB-LAMP was 8.2%, 77.7%, and 67.2% against CCRS as the reference; and the specificity of the three was 100.0, 100.0, and 96.2% against the same standard. A combination of pathology and TB-LAMP would increase the sensitivity and specificity to 84.7 and 96.0%. Using TB-LAMP to diagnose TB empyema using pleural tissue samples obtained from pleural decortication was faster with satisfactory performance. Conclusion: TB-LAMP has great potential in faster and more accurate diagnosis of TB empyema. Our findings provide insights for optimizing diagnostic algorithms for TB empyema.