Successful treatment of disseminated nocardiosis diagnosed by metagenomic next-generation sequencing: A case report and review of literature.

BACKGROUND: Nocardia paucivorans is an infrequently found bacterium with the potential to cause severe infection, with a predilection for the central nervous system, both in immunocompromised and immunocompetent individuals. Rapid etiological diagnosis of nocardiosis can facilitate timely and rational antimicrobial treatment. Metagenomic next-generation sequencing (mNGS) can improve the rate and reduce the turnaround time for the detection of Nocardia. CASE SUMMARY: A 49-year-old man was admitted to hospital with cough and hemoptysis. Imaging revealed pulmonary consolidation as well as multiple brain lesions. Nocardia asiatica and Nocardia beijingensis were rapidly detected by mNGS of bronchoalveolar lavage fluid (BALF) while bacterial culture of BALF and pathological biopsy of lung tissue were negative. In early stages, he was treated with trimethoprim-sulfamethoxazole (TMP-SMZ) and linezolid by individual dose adjustment based on serum concentrations and the adverse effects of thrombocytopenia and leukopenia. The treatment was then replaced by TMP-SMZ and ceftriaxone or minocycline. He was treated with 8 mo of parenteral and/or oral antibiotics, and obvious clinical improvement was achieved with resolution of pulmonary and brain lesions on repeat imaging. CONCLUSION: mNGS provided fast and precise pathogen detection of Nocardia. In disseminated nocardiosis, linezolid is an important alternative that can give a better outcome with the monitoring of linezolid serum concentrations and platelet count.

[Receptor for advanced glycation end products upregulates MUC5AC expression and promotes mucus overproduction in mice with toluene diisocyanate-induced asthma].

OBJECTIVE: To explore the role of the receptor for advanced glycation end products (RAGE) in regulating the expression of MUC5AC and mucus production in a mouse model of toluene diisocyanate (TDI)?induced asthma. METHODS: BALB/c mice were randomly divided into control group, vehicle (AOO) group, TDI?induced asthma group and RAGE inhibitor (FPS?ZM1) group. PAS staining, Western blotting, and immunohistochemistry were used to analyze the changes in mucus production and MUC5AC expression in the airway of the mice, and the expression of p?ERK was detected with Western blotting. In vitro cultured human bronchial epithelial cell line 16HBE was transfected with lentiviral vector carrying short hairpin RNA targeting RAGE (shRNA?RAGE) and subsequently challenged with a TDI?human serum albumin (TDI-HSA) conjugate, and the changes in cellular MUC5AC mRNA expression as detected using RT-PCR; the protein expressions of ERK and p?ERK in the cells were examined with Western blotting. The effect of ERK inhibitor U0126 pretreatment on MUC5AC mRNA expression was also analyzed in the cells. RESULTS: Compared with the control mice, TDI-induced asthmatic mice showed significantly higher rates of PAS positivity and increased MUC5AC and p?ERK expressions in the airway (P<0.05). Treatment with FPS?ZM1 significantly decreased PAS positivity and lowered MUC5AC and p?ERK expressions in the airway of the asthmatic mice (P<0.05). Exposure of 16HBE cells to TDI?HSA caused a significant increase in MUC5AC mRNA expression and p?ERK protein expression (P<0.05), while RAGE knockdown obviously suppressed TDI?HSA-induced upregulation of p-ERK and MUC5AC mRNA (P<0.05). Treatment with the ERK inhibitor U0126 also lowered TDI?HSA?induced up?regulation of MUC5AC mRNA in the cells (P<0.05). CONCLUSION: RAGE signaling induces MUC5AC expression via extracellular signal-regulated kinase pathway to promote mucus overproduction in mice with TDI-induced asthma.

[Role of epidermal growth factor receptor in house dust mite-induced airway epithelial barrier dysfunction].

OBJECTIVE: To investigate the role of epidermal growth factor receptor (EGFR) signaling pathway in bronchial epithelial actin stress fiber (F-actin) rearrangement induced by house dust mite (HDM). METHODS: Normal human bronchial epithelial cells (16HBE) were stimulated with HDM with or without pretreatment with AG-1478, an EGFR inhibitor. The levels of phospho(p)-EGFR, F-actin, E-cadherin and ß-catenin in the cell cultures were detected with Western blotting. The localizations of F-actin, E-cadherin and ß-catenin in the bronchial epithelial cells were determined with immunofluorescence assay, and the transmembrane electrical resistance (TER) and FITC-dextran flux (FITC-DX) in the cells were measured to assess the barrier function of the bronchial epithelia. RESULTS: HDM stimulation of the cells for 10 min resulted in significantly increased p-EGFR expression (P<0.05) without causing obvious changes in the expression of E-cadherin (P>0.05) or ß-catenin (P>0.05). Immunofluorescence assay revealed delocalization of E-cadherin and ß-catenin in HDM-treated 16HBE cells, shown by their diffusion from the cell membrane to the cytoplasm. In HDM-treated cells, the TER was significantly decreased to (70.00∓4.33)% and the FITC-DX was significantly increased to (115.98∓4.34)%; Inhibition of EGFR reversed the delocalization of E-cadherin and ß-catenin, improved the TER to (90.00∓3.75)% and lowered the FITC-DX to (101.10∓2.10)%. HDM induced increased expression and rearrangement of F-actin, which was obviously inhibited by pretreatment of the cells with AG-1478 (P<0.05). CONCLUSION: EGFR signaling pathway mediates HDM-induced F-actin rearrangement in human bronchial epithelial cells to contribute to epithelial barrier dysfunction.

Extracellular heat shock protein 90α mediates HDM-induced bronchial epithelial barrier dysfunction by activating RhoA/MLC signaling.

BACKGROUND: The disruption and hyperpermeability of bronchial epithelial barrier are closely related to the pathogenesis of asthma. House dust mite (HDM), one of the most important allergens, could increase the airway epithelial permeability. Heat shock protein (Hsp) 90α is also implicated in the lung endothelial barrier dysfunction by disrupting RhoA signaling. However, the effect of extracellular Hsp90α (eHsp90α) on the bronchial epithelial barrier disruption induced by HDM has never been reported. METHODS: To investigate the involvement of eHsp90α in the bronchial epithelial barrier disruption induced by HDM, normal human bronchial epithelial cell line 16HBE14o- (16HBE) cells were treated by HDM, human recombinant (hr) Hsp90α and hrHsp90ß respectively and pretreated by1G6-D7, a specific anti-secreted Hsp90α monoclonal antibody (mAb). Hsp90α-silencing cells were also constructed. To further evaluate the role of RhoA signaling in this process, cells were pretreated by inhibitors of Rho kinase, GSK429286A and Y27632 2HCl. Transepithelial electrical resistance (TEER) and FITC-dextran flux (FITC-DX) were examined as the epithelial barrier function. Expression and localization of adherens junctional proteins E-cadherin and ß-catenin were evaluated by western blotting and immunofluorescence respectively. The level of eHsp90α was investigated by concentration and purification of condition media. RhoA activity was determined by using a Rho G-LISA® RhoA activation assay kitTM biochem kit, and the phosphorylation of myosin light chain (MLC), the downstream signal molecule of RhoA, was assessed by western blotting. RESULTS: The epithelial barrier disruption and the loss of adherens junctional proteins E-cadherin and ß-catenin in cytomembrane were observed in HDM-treated 16HBE cells, paralleled with the increase of eHsp90α secretion. All of which were rescued in Hsp90α-silencing cells or by pretreating 16HBE cells with 1G6-D7. Also, 1G6-D7 suppressed RhoA activity and MLC phosphorylation induced by HDM. Furthermore, inhibitors of Rho kinase prevented and restored the airway barrier disruption. Consistently, it was hrHsp90α instead of hrHsp90ß that promoted barrier dysfunction and activated RhoA/MLC signaling in 16HBE cells. CONCLUSIONS: The eHsp90α mediates HDM-induced human bronchial epithelial barrier dysfunction by activating RhoA/MLC signaling, suggesting that eHsp90α is a potential therapeutic target for treatment of asthma.

BIM Gene Polymorphism Lowers the Efficacy of EGFR-TKIs in Advanced Nonsmall Cell Lung Cancer With Sensitive EGFR Mutations: A Systematic Review and Meta-Analysis.

The strong association between bcl-2-like 11 (BIM) triggered apoptosis and the presence of epidermal growth factor receptor (EGFR) mutations has been proven in nonsmall cell lung cancer (NSCLC). However, the relationship between EGFR-tyrosine kinase inhibitor's (TKI's) efficacy and BIM polymorphism in NSCLC EGFR is still unclear.Electronic databases were searched for eligible literatures. Data on objective response rates (ORRs), disease control rates (DCRs), and progression-free survival (PFS) stratified by BIM polymorphism status were extracted and synthesized based on random-effect model. Subgroup and sensitivity analyses were conducted.A total of 6 studies that involved a total of 773 EGFR mutant advanced NSCLC patients after EGFR-TKI treatment were included. In overall, non-BIM polymorphism patients were associated with significant prolonged PFS (hazard ratio 0.63, 0.47-0.83, P = 0.001) compared to patients with BIM polymorphism. However, only marginal improvements without statistical significance in ORR (odds ratio [OR] 1.71, 0.91-3.24, P = 0.097) and DCR (OR 1.56, 0.85-2.89, P = 0.153) were observed. Subgroup analyses showed that the benefits of PFS in non-BIM polymorphism group were predominantly presented in pooled results of studies involving chemotherapy-naive and the others, and retrospective studies. Additionally, we failed to observe any significant benefit from patients without BIM polymorphism in every subgroup for ORR and DCR.For advanced NSCLC EGFR mutant patients, non-BIM polymorphism ones are associated with longer PFS than those with BIM polymorphism after EGFR-TKIs treatment. BIM polymorphism status should be considered an essential factor in studies regarding EGFR-targeted agents toward EGFR mutant patients.

[Risk factors for in-hospital mortality in patients with acute exacerbation of chronic obstructive pulmonary disease].

OBJECTIVE: To explore the risk factors for hospitalization case fatality of patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). METHODS: A retrospective review of medical records was performed for 182 hospitalized AECOPD patients at Nanfang Hospital from January 2010 to August 2012. Their general information, condition in stable stage, the results of spirometry, blood routine test, blood gas analysis and C-reactive protein (CRP) were collected and analyzed. The risk factors for mortality were analyzed by multivariable Logistic regression. RESULTS: Among them, 42 died during hospitalization. Univariate analysis revealed that 8 factors had significant differences between two groups (all P < 0.05): high exacerbation risk (death vs improvement group, 90.4% vs 70.0%) , low peripheral absolute lymphocyte count (73.8% vs 47.1%), high CRP (50.0% vs 17.1%), concurrent anemia (50.0% vs 27.1%), hypoproteinemia (71.4% vs 46.4%), hypercapnia (64.3% vs 30.7%), chronic pulmonary heart disease (76.1% vs 40.7%) and ischemic heart disease (19.0% vs 7.0%). By multiple Logistic regression analysis, high CRP (OR = 3.226, P = 0.009), hypercapnia (OR = 2.928, P = 0.013), chronic pulmonary heart disease (OR = 2.510, P = 0.045), low peripheral absolute lymphocyte count (OR = 2.488, P = 0.045) were the independent risk factors for hospitalization case fatality of AECOPD patients. CONCLUSION: Low peripheral absolute lymphocyte count, high CRP, hypercapnia and chronic pulmonary heart disease were the independent risk factors for mortality in hospitalized AECOPD patients.

[Post-therapeutic change of cathelicidin LL-37 in asthmatics of different inflammatory phenotypes].

OBJECTIVE: To explore the post-therapeutic change of cathelicidin LL-37 in asthmatics of different inflammatory phenotypes. METHODS: Thirty-four patients with initially diagnosed asthma (asthma group) and 14 normal subjects (control group) were recruited at Nanfang Hospital from August 2009 to August 2010 for this prospective study. Sputum and venous blood samples were collected and analyzed for cell differential. Eosinophilic asthma was defined as the count of sputum eosinophils ≥ 3%. The LL-37 concentrations in plasma and sputum supernatant were measured by enzyme-linked immunosorbent assay (ELISA) kit. The subjects were treated with budesonide/formoterol (160/4.5 µg) one inhalation twice daily and re-examined after 1 month. RESULTS: Prior to treatment, there were no differences between the asthma and control groups in the levels of LL-37 in plasma and sputum supernatant (P = 0.427,0.427). The plasma concentrations of LL-37 in asthma group were negatively correlated with baseline forced expiratory volume in one second (FEV(1), r = -0.470, P = 0.005), percent predicted of FEV(1) (FEV(1)%pred, r = -0.421, P = 0.013) and forced vital capacity (FVC, r = -0.367, P = 0.033). After treatment, the plasma and sputum supernatant concentrations of LL-37 (M (Q(R))) in the asthma group (5.6 (16.2), 65.6 (184.0) µg/L) were significantly higher than those baseline concentrations (5.03 (9.21), 28.40(109.76) µg/L, P = 0.005, 0.015). In the eosinophilic asthma subgroup, the plasma and sputum supernatant concentrations of LL-37 (M (Q(R))) after treatment (5.3 (19.3), 65.6 (185.2) µg/L) were significantly higher than those baseline concentrations (6.7 (8.9) L, 35.3 (102.0) µg/L, P = 0.021,0.014). And in the non-eosinophilic asthma subgroup, the changes of plasma and sputum supernatant concentrations of LL-37 showed no significant differences (P = 0.139, 0.386). In the asthma group, the correlations between plasma concentrations of LL-37 and FEV(1), FEV(1)%pred, FVC were not statistically significant (P = 0.283, 0.706,0.272) after treatment. CONCLUSIONS: LL-37 may participate in the aggravation of asthma. The elevated concentrations of LL-37 in eosinophilic asthma is probably due to the resolved suppression of LL-37 expression by eosinophilic inflammation. But its mechanism needs further researches.