Multiple impacts of the COVID-19 pandemic and antimicrobial stewardship on antimicrobial resistance in nosocomial infections: an interrupted time series analysis.

Objectives: The emergency response to the COVID-19 pandemic may disrupt hospital management activities of antimicrobial resistance (AMR). This study aimed to determine the changing AMR trend over the period in China when stringent COVID-19 response measures were implemented. Methods: This retrospective study was conducted in a designated hospital for COVID-19 patients in Guangzhou, China from April 2018 to September 2021. The prevalence of 13 antimicrobial-resistant bacteria was compared before and after the COVID-19 responses through Chi-square tests. Interrupted time series (ITS) models on the weekly prevalence of AMR were established to determine the changing trend. Controlled ITS models were performed to compare the differences between subgroups. Results: A total of 10,134 isolates over 1,265 days were collected. And antimicrobial-resistant strains presented in 38.6% of the testing isolates. The weekly AMR prevalence decreased by 0.29 percentage point (95% CI [0.05-0.80]) after antimicrobial stewardship (AMS) policy, despite an increase in the prevalence of penicillin-resistant Streptococcus pneumoniae (from 0/43 to 15/43, p < 0.001), carbapenem-resistant Escherichia coli (from 20/1254 to 41/1184, p = 0.005), and carbapenem-resistant Klebsiella pneumoniae (from 93/889 to 114/828, p = 0.042). And the changing trend did not vary by gender (male vs. female), age (<65 vs. ≥65 years), service setting (outpatient vs. inpatient), care unit (ICU vs. non-ICU), the primary site of infection (Lung vs. others), and Gram type of bacteria (positive vs. negative). Conclusion: The response to COVID-19 did not lead to an increase in overall AMR; however, it appears that management strategy on the prudent use of antimicrobials likely contributed to a sizable long-term drop. The frequency of several multidrug-resistant bacteria continues to increase after the COVID-19 epidemic. It is crucial to continue to monitor AMR when COVID-19 cases have surged in China after the relaxation of restriction measures.

Effects of pay-for-performance based antimicrobial stewardship on antimicrobial consumption and expenditure: An interrupted time series analysis.

Objectives: To evaluate the impact of pay-for-performance on antimicrobial consumption and antimicrobial expenditure in a large teaching hospital in Guangzhou, China. Methods: We collected data from hospital information system from January 2018 through September 2022 in the inpatient wards. Antimicrobial consumption was evaluated using antibiotic use density (AUD) and antibiotic use rate (AUR). The economic impact of intervention was assessed by antimicrobial expenditure percentage. The data was analyzed using interrupted time series (ITS) analysis. Results: Following the implementation of the intervention, immediate decreases in the level of AUD were observed in Department of Hematology Unit 3 (ß = -66.93 DDDs/100PD, P = 0.002), Urology (ß = -32.80 DDDs/100PD, P < 0.001), Gastrointestinal Surgery Unit 3 (ß = -11.44 DDDs/100PD, P = 0.03), Cardiac Surgery (ß = -14.30 DDDs/100PD, P = 0.01), ICU, Unit 2 (ß = -81.91 DDDs/100PD, P = 0.02) and Cardiothoracic Surgery ICU (ß = -41.52 DDDs/100PD, P = 0.05). Long-term downward trends in AUD were also identified in Organ Transplant Unit (ß = -1.64 DDDs/100PD, P = 0.02). However, only Urology (ß = -6.56 DDDs/100PD, P = 0.02) and Gastrointestinal Surgery Unit 3 (ß = -8.50 %, P = 0.01) showed an immediate decrease in AUR, and long-term downward trends in AUR were observed in Pediatric ICU (ß = -1.88 %, P = 0.05) and ICU Unit 1 (ß = -0.55 %, P = 0.02). Conclusion: This study demonstrates that the adoption of pay-for-performance effectively reduces antibiotic consumption in specific departments of a hospital in Guangzhou in the short term. However, it is important to recognize that the long-term impact of such interventions is often limited. Additionally, it should be noted that the overall effectiveness of the intervention across the entire hospital was not significant.

Global antimicrobial resistance and antibiotic use in COVID-19 patients within health facilities: A systematic review and meta-analysis of aggregated participant data.

OBJECTIVES: The COVID-19 pandemic has posed a significant threat to the global healthcare system, presenting a major challenge to antimicrobial stewardship worldwide. This study aimed to provide a comprehensive and up-to-date picture of global antimicrobial resistance (AMR) and antibiotic use in COVID-19 patients. METHODS: We conducted a systematic review to determine the prevalence of AMR and antibiotic usage among COVID-19 patients receiving treatment in healthcare facilities. Our search encompassed the PubMed, Web of Science, Embase, and Scopus databases, spanning studies published from December 2019 to May 2023. We utilized random-effects meta-analysis to assess the prevalence of multidrug-resistant organisms (MDROs) and antibiotic use in COVID-19 patients, aligning with both the WHO's priority list of MDROs and the AWaRe list of antibiotic products. Estimates were stratified by region, country, and country income. Meta-regression models were established to identify predictors of MDRO prevalence and antibiotic use in COVID-19 patients. The study protocol was registered with PROSPERO (CRD 42023449396). RESULTS: Among the 11,050 studies screened, 173 were included in the review, encompassing a total of 892,312 COVID-19 patients. MDROs were observed in 42.9% (95% CI 31.1-54.5%, I2 = 99.90%) of COVID-19 patients: 41.0% (95% CI 35.5-46.6%) for carbapenem-resistant organisms (CRO), 19.9% (95% CI 13.4-27.2%) for methicillin-resistant Staphylococcus aureus (MRSA), 24.9% (95% CI 16.7-34.1%) for extended-spectrum beta-lactamase-producing organisms (ESBL), and 22.9% (95% CI 13.0-34.5%) for vancomycin-resistant Enterococcus species (VRE), respectively. Overall, 76.2% (95% CI 69.5-82.9%, I2 = 99.99%) of COVID-19 patients were treated with antibiotics: 29.6% (95% CI 26.0-33.4%) with "Watch" antibiotics, 22.4% (95% CI 18.0-26.7%) with "Reserve" antibiotics, and 16.5% (95% CI 13.3-19.7%) with "Access" antibiotics. The MDRO prevalence and antibiotic use were significantly higher in low- and middle-income countries than in high-income countries, with the lowest proportion of antibiotic use (60.1% (95% CI 52.1-68.0%)) and MDRO prevalence (29.1% (95% CI 21.8-36.4%)) in North America, the highest MDRO prevalence in the Middle East and North Africa (63.9% (95% CI 46.6-81.2%)), and the highest proportion of antibiotic use in South Asia (92.7% (95% CI 90.4-95.0%)). The meta-regression identified antibiotic use and ICU admission as a significant predictor of higher prevalence of MDROs in COVID-19 patients. CONCLUSIONS: This systematic review offers a comprehensive and current assessment of MDRO prevalence and antibiotic use among COVID-19 patients in healthcare facilities. It underscores the formidable challenge facing global efforts to prevent and control AMR amidst the backdrop of the COVID-19 pandemic. These findings serve as a crucial warning to policymakers, highlighting the urgent need to enhance antimicrobial stewardship strategies to mitigate the risks associated with future pandemics.

Nickel-Catalyzed Ethylene Copolymerization with Vinylalkoxysilanes: A Computational Study.

Since the discovery of α-diimine catalysts in 1995, an extensive series of Brookhart-type complexes have shown their excellence in catalyzing ethylene polymerizations with remarkable activity and a high molecular weight. However, although this class of palladium complexes has proven proficiency in catalyzing ethylene copolymerization with various polar monomers, the α-diimine nickel catalysts have generally exhibited a much worse performance in these copolymerizations compared to their palladium counterparts. Recently, Brookhart et al. reported a notable exception, demonstrating that α-diimine nickel catalysts could catalyze the ethylene copolymerization with some vinylalkoxysilanes effectively, producing functionalized polyethylene incorporating trialkoxysilane (-Si(OR)3) groups. This breakthrough is significant since Pd-catalyzed copolymerizations are commercially less usable due to the high cost of palladium. Thus, the utilization of Ni, given its abundance in raw materials and cost-effectiveness, is a landmark in ethylene/polar vinyl monomer copolymerization. Inspired by these findings, we used density functional theory (DFT) calculations to investigate the mechanistic study of ethylene copolymerization with vinyltrimethoxysilane (VTMoS) catalyzed by Brookhart-type nickel catalysts, aiming to elucidate the molecular-level understanding of this unique reaction. Initially, the nickel complexes and cationic active species were optimized through DFT calculations. Subsequently, we explored the mechanisms including the chain initiation, chain propagation, and chain termination of ethylene homopolymerization and copolymerization catalyzed by Brookhart-type complexes. Finally, we conducted an energetic analysis of both the in-chain and chain-end of silane enchainment. It was found that chain initiation is the dominant step in the ethylene homopolymerization catalyzed by the α-diimine Ni complex. The 1,2- and 2,1-insertion of vinylalkoxysilane exhibit similar barriers, explaining the fact that both five-membered and four-membered chelates were identified experimentally. After the VTMoS insertion, the barriers of ethylene reinsertion become higher, indicating that this step is the rate-determining step, which could be attributed to the steric hindrance between the incoming ethylene and the bulky silane substrate. We have also reported the energetic analysis of the distribution of polar substrates. The dominant pathway of chain-end -Si(OR)3 incorporation is suggested as chain-walking → ring-opening → ethylene insertion, and the preference of chain-end -Si(OR)3 incorporation is primarily attributed to the steric repulsion between the pre-inserted silane group and the incoming ethylene molecule, reducing the likelihood of in-chain incorporation.

Aponermin or placebo in combination with thalidomide and dexamethasone in the treatment of relapsed or refractory multiple myeloma (CPT-MM301): a randomised, double-blinded, placebo-controlled, phase 3 trial.

BACKGROUND: Aponermin, a circularly permuted tumor necrosis factor-related apoptosis-inducing ligand, is a potential death receptor 4/5-targeted antitumour candidate. Previous phase 1/2 studies have demonstrated the efficacy of aponermin in patients with relapsed or refractory multiple myeloma (RRMM). To confirm the superiority of aponermin plus thalidomide and dexamethasone (aponermin group) over placebo plus thalidomide and dexamethasone (placebo group) in RRMM, a randomized, double-blinded, placebo controlled phase 3 trial was performed. METHODS: Four hundred seventeen patients with RRMM who had previously received at least two regimens were randomly assigned (2:1) to receive aponermin, thalidomide, and dexamethasone or placebo, thalidomide, and dexamethasone. The primary endpoint was progression-free survival (PFS). Key secondary endpoints included overall survival (OS) and overall response rate (ORR). RESULTS: A total of 415 patients received at least one dose of trial treatment (276 vs. 139). The median PFS was 5.5 months in the aponermin group and 3.1 months in the placebo group (hazard ratio, 0.62; 95% confidence interval [CI], 0.49-0.78; P < 0.001). The median OS was 22.4 months for the aponermin group and 16.4 months for the placebo group (hazard ratio, 0.70; 95% CI, 0.55-0.89; P = 0.003). Significantly higher rates of ORR (30.4% vs. 13.7%, P < 0.001) and very good partial response or better (14.1% vs. 2.2%, P < 0.0001) were achieved in the aponermin group than in the placebo group. Treatment with aponermin caused hepatotoxicity in some patients, as indicated by the elevated alanine transaminase, aspartate transaminase, or lactate dehydrogenase levels (52.2% vs. 24.5%, 51.1% vs. 19.4% and 44.9% vs. 21.6%, respectively), mostly grade 1/2, transient and reversible. The main grade 3/4 adverse events included neutropenia, pneumonia and hyperglycemia. The incidence of serious adverse events was similar between the two groups (40.6% vs. 37.4%). There was no evidence that aponermin leads to hematological toxicity, nephrotoxicity, cardiotoxicity, or secondary tumors. CONCLUSIONS: Aponermin plus thalidomide and dexamethasone significantly improved PFS, OS and ORR with manageable side effects in RRMM patients who had received at least two prior therapies. These results support the use of aponermin, thalidomide, and dexamethasone as a treatment option for RRMM patients. TRIAL REGISTRATION: The trial was registered at http://www.chictr.org.cn as ChiCTR-IPR-15006024, 17/11/2014.

Synergistic antitumor effects of circularly permuted TRAIL with doxorubicin in triple-negative breast cancer.

Circularly permuted TRAIL (CPT), a novel recombinant TRAIL mutant, is a potent antitumor agent. However, its efficacy in triple-negative breast cancer (TNBC) remains unclear. Treatment with CPT alone and in combination with doxorubicin (Dox) is explored for its effects on the proliferation and apoptosis of MDA-MB-231 (MB231) and MDA-MB-436 (MB436) breast cancer cells in vitro and in vivo. Here, we show that CPT combined with Dox exhibits time- and dose-dependent synergy to inhibit cell viability and enhance apoptosis of MB231 and MB436 cells. Combined treatment substantially increases caspase-8, caspase-3, and PARP cleavage in both cell lines and significantly suppresses tumor growth in nude mice bearing MB231 xenografts. Collectively, our findings demonstrate that treatment with CPT in combination with Dox exerts synergistic antitumor effects through activation of the caspase cascade pathway, a mechanism that is partly dependent on the Dox-induced upregulation of death receptor 4 and death receptor 5. Therefore, CPT combined with Dox may be a feasible therapeutic strategy for the management of TNBC.

The association between ambient temperature and antimicrobial resistance of Klebsiella pneumoniae in China: a difference-in-differences analysis.

Introduction: Antimicrobial resistance (AMR) of Klebsiella pneumoniae (K. pneumoniae) poses a significant global public health threat and is responsible for a high prevalence of infections and mortality. However, knowledge about how ambient temperature influences the AMR of K. pneumoniae is limited in the context of global warming. Methods: AMR data of 31 Chinese provinces was collected from the China Antimicrobial Resistance Surveillance System (CARSS) between 2014 and 2020. Socioeconomic and meteorological data were collected from the China Statistical Yearbook during the same period. A modified difference-in-differences (DID) approach was applied to estimate the association between ambient temperature and third-generation cephalosporin-resistant K. pneumoniae (3GCRKP) and carbapenem-resistant K. pneumoniae (CRKP). Furthermore, moderating effects of socioeconomic factors were also evaluated. Results: Every 1°C increase in annual average temperature was associated with a 4.7% (relative risk (RR):1.047, 95% confidence intervals (CI): 1.031-1.082) increase in the detection rate of 3GCRKP, and a 10.7% (RR:1.107, 95% CI: 1.011-1.211) increase in the detection rate of CRKP. The relationships between ambient temperature and 3GCRKP and CRKP were found to be moderated by socioeconomic status (GDP per capita, income per capita, and consumption per capita; the interaction p-values <0.05), where higher economic status was found to strengthen the effects of temperature on the detection rate of 3GCRKP and weaken the effects on the detection rate of CRKP. Discussion: Ambient temperature was found to be positively associated with AMR of K. pneumoniae, and this association was moderated by socioeconomic status. Policymakers should consider the impact of global warming and high temperatures on the spread of 3GCRKP and CRKP when developing strategies for the containment of AMR.

Effects of social norm feedback on antibiotic prescribing and its characteristics in behaviour change techniques: a mixed-methods systematic review.

Low-cost and low-barrier antibiotic stewardship strategies are urgently needed to deal with the widespread problem of antibiotic resistance. Social norm feedback could be a promising strategy. In this mixed-methods systematic review (PROSPERO: CRD42022361039), we aimed to identify the key behaviour change techniques used in social norm feedback for antibiotic stewardship and assess their effectiveness in reducing antibiotic prescribing. We searched PubMed, Embase, Web of Science, and Scopus for peer-reviewed studies published between Jan 1, 2000, and Jan 20, 2022. 3547 studies were screened, of which 23 studies reporting the effects of social norm feedback interventions on antibiotic prescribing met the inclusion criteria. 19 behaviour change techniques were tested in the included studies. The meta-analyses showed that social norm feedback is an effective strategy for reducing antibiotic prescribing, with an overall rate difference of 4% (p<0·0001). The behaviour change technique with the highest effective ratio (ER=13) was information about health consequences, followed by instruction on how to perform the behaviour (ER=9) and adding objects to the environment (ER=9). Social norm feedback is a promising strategy to reduce antibiotic prescribing, and can be incorporated into the clinical decision-making support system.

A novel therapeutic strategy to close bronchopleural fistula related to Mycobacterium chelonae in elderly patients: two case reports and literature review.

Background: Mycobacterium chelonae (M. chelonae) empyema complicated with bronchopleural fistula (BPF) remains a significant challenge in diagnosis and treatment and the clinical outcomes are often unsatisfactory, especially in elderly patients. There is a paucity data related to the management of the condition. This is the first well-documented report of the therapeutic experience with bronchoscopic closure of a bronchopleural fistula with empyema related to M. chelonae infection in the elderly patients. Case Description: An 86-year-old non-smoking male with a history of diabetes mellitus, emphysema, and bronchiectasis, and a 72-year-old non-smoking male with two past surgeries for lung cancer, both presented with chronic fever, purulent expectoration, hemoptysis, and dyspnea, and were diagnosed with bronchopleural fistula associated with M. chelonae infection. Long-term antibiotic regimens, prolonged thoracic drainage, and endoscopic closure with biological glue were all unsuccessful. The culprit bronchus was identified precisely with the combined assistance of the instillation of methylene blue and the Chartis digital air leak monitoring system. Bronchoscopic interventional therapy was successfully performed using the Zephyr one-way endobronchial valve or the Amplatzer patent ductus arteriosus occluder. Finally, two patients succeeded in removing chest tube, and were able to conduct daily activities. Conclusions: The successful bronchoscopic closure with the combined assistance of methylene blue and the Chartis digital air leak monitoring system provided valuable experience and novel strategy in dealing with BPF related to M. chelonae in the elderly and high-risk inoperable patients.

Effect of multiplicity of infection on the evasion of neutrophil killing by Streptococcus agalactiae isolated from clinical mastitis bovine.

Streptococcus agalactiae (S. agalactiae) causes intramammary infection in dairy cows. Increased neutrophils and a high bacterial load are important characteristics of bovine bacterial mastitis. We hypothesized that the multiplicity of infection (MOI) of S. agalactiae in bovine mastitis plays an important role in bacterial pathogenicity by modulating the neutrophil response to promote bacterial survival. Neutrophils from BALB/c mice were infected with the bovine mastitis isolate of S. agalactiae SAG-FX17 at various MOIs, and neutrophil responses were investigated. Infecting neutrophils with SAG-FX17 at an MOI of 1 induced reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) formation. Bacteria at an MOI of 10 suppressed neutrophil responses, including ROS bursts, NET formation, and cell necrosis, which are conducive to bacterial multiplication within 30 min postinfection. In addition, neutrophils are destroyed by SAG-FX17 at an MOI of 100 or greater. This study identified the MOIs related to the ROS and NET suppression caused by SAG-FX17, and the findings suggested that interventions to decrease bacterial loads before the MOI of 10 could be necessary and effective to harness the power of innate immune response to eliminate pathogens.

NADPH oxidase-derived reactive oxygen species production activates the ERK1/2 pathway in neutrophil extracellular traps formation by Streptococcus agalactiae isolated from clinical mastitis bovine.

Streptococcus agalactiae (S. agalactiae) continues to be challenging for milk quality in some countries and leads to huge economic losses. A large number of neutrophils are recruited into inflammatory foci when S. agalactiae infection occurs, and most studies have focused on the interaction between neutrophil extracellular traps (NETs) and this bacterium in the context of human pathogenicity. However, there is little information on the NET formation mechanism induced by S. agalactiae in the context of bovine mastitis. Here, neutrophils isolated from BALB/c mice were infected with S. agalactiae SAG-FX17, and NET formation was evaluated. SAG-FX17 could induce NADPH oxidase-derived reactive oxygen species (NOX-ROS)-dependent NET formation, and 21.8% of bacteria could be eliminated by NETs via NET DNA and associated proteins. SAG-FX17 could induce the phosphorylation of p38 MAPK, ERK1/2 MAPK, and JNK/SAPK in neutrophils. However, only ERK1/2 MAPK was shown to play an important role in SAG-FX17-induced NET formation. Importantly, NOX-ROS production occurs upstream of ERK1/2 MAPK activation and then induces NET release. ERK1/2 MAPK phosphorylation can, in turn, enhance NOX-ROS generation, which further contributes to NET release and bacterial elimination. This study provides evidence of the molecular mechanism underlying serotype Ia S. agalactiae SAG-FX17-induced NET formation and the interaction between bacteria and NETs, and these findings will increase our knowledge about bacterial mastitis in dairy cattle and contribute to the prevention and clinical treatment of bovine mastitis.

Myostatin is involved in skeletal muscle dysfunction in chronic obstructive pulmonary disease via Drp-1 mediated abnormal mitochondrial division.

Background: Skeletal muscle dysfunction (SMD) is one of the most prominent extrapulmonary effects of chronic obstructive pulmonary disease (COPD). Myostatin negatively regulates the growth of skeletal muscle. We confirmed that myostatin expression is significantly increased in the quadriceps femoris muscle tissue of rats with COPD and is involved in the development of SMD in COPD, but the mechanism by which this occurs has yet to be uncovered. Dynamin-related protein 1 (Drp-1) has been shown to promote apoptosis and affect cellular energy metabolism by mediating enhanced mitochondrial division. Preliminary findings from our group illustrated that mitochondrial division and Drp-1 expression were increased in COPD quadriceps femoris cells. However, it is not yet clear whether mitochondrial dynamics are affected by myostatin in COPD quadriceps myocytes. Methods: The study sought to explore the effects and potential mechanisms of myostatin on skeletal muscle atrophy, mitochondrial dynamics, apoptosis, and the links between related processes in COPD. Results: Our findings showed that cigarette smoke exposure stimulated an increase in myostatin, increased superoxide production, decreased mitochondrial membrane potential, significantly promoted Drp-1-mediated mitochondrial fission, and promoted apoptosis. Conclusions: In summary, our study demonstrated that cigarette smoke led to increased Drp-1 expression and enhanced mitochondrial division by upregulating myostatin, which in turn promoted apoptosis and affected cellular energy metabolism, leading to the development of SMD in COPD. This study extends understandings of skeletal muscle function in COPD and provides a basis for the use of myostatin and Drp-1 as novel therapeutic targets for SMD in COPD.

Clinical analysis of hospital acquired mycoplasma pneumoniae infection after cardiac surgery: a case series.

Background: Mycoplasma pneumoniae (MP) is a common pathogen of community-acquired respiratory infections. The clinical characteristics hospital-acquired MP infections are rarely reported in the literature. Our ward is mainly responsible for the management of patients during the perioperative period of cardiac surgery. Several patients had fever during the improvement of their condition after cardiac surgery, and the effect of upgrading antibiotics and increasing the antibacterial spectrum was not good. Methods: Using inpatient data of Guangdong Provincial People's Hospital, we conducted a retrospective case series study of hospital-acquired MP infection after cardiac surgery from January 2015 to December 2020 to investigate the clinical characteristics. Clinical data was extracted from patients with a confirmed diagnosis of MP infection after >48 hours of hospitalization. All analyses for this study were descriptive. Data were expressed as mean ± standard deviation (SD), median with range or number with percentage as appropriate. Results: We totally included 22 patients. The time of onset of hospital-acquired MP infection after surgery was 23.32±12.57 days, and the duration of antibiotic use before the onset of infection was 4-40 days. Both fever and sore throat were the main symptoms of nosocomial MP infection, and the rash was the most common physical sign. Laboratory tests were normal for peripheral blood leukocyte count and procalcitonin in most patients (17 cases), while the lymphocyte count was decreased in 10 cases. A single serum anti-MP antibody titer ≥1:160 combined with clinical manifestations and imaging helped confirm nosocomial MP infection, although a double serum anti-MP antibody (four-fold change in titer) wasn't seen. With quinolone therapy, such as levofloxacin, all the patients' temperature gradually returned to normal and were discharged uneventfully. Conclusions: Patients after cardiac surgery should be aware of the presence of hospital-acquired MP infection when they develop new fever accompanied by atypical bacterial infection signs such as sore throat and rash during treatment. In such cases, changes in MP antibody titers need to be monitored and anti-MP therapy is required.

Extracellular vesicles derived from lung cancer cells exposed to intermittent hypoxia upregulate programmed death ligand 1 expression in macrophages.

PURPOSE: Intermittent hypoxia (IH), a hallmark of obstructive sleep apnea (OSA), compromises immune surveillance through the upregulation of programmed cell death-1 ligand (PD-L1). Tumor-released extracellular vesicles (EVs) have been reported to modulate immunosuppressive activities. We investigated whether or not EVs derived from intermittent hypoxic lung cancer cells can alter the expression of PD-L1 in macrophages. METHODS: The expression of PD-L1+monocytes from 40 patients with newly diagnosed non-small-cell lung cancer (NSCLC) and with (n=21) or without (n=19) OSA were detected. Plasma EVs isolated from NSCLC patients with moderate-severe OSA (n=4) and without OSA (n=4) were co-cultured with macrophages. A549 cells were exposed to normoxia or IH (48 cycles of 5 min of 1% O2 hypoxia, followed by 5 min of normoxia). EVs were isolated from cell supernatant and were co-cultured with macrophages differentiated from THP-1. PD-L1 and hypoxia-inducible factor-1 α (HIF-1α) expressions were measured by flow cytometry, immunofluorescence, and Western blot analysis. RESULTS: PD-L1+monocytes were elevated in NSCLC patients with OSA and increased with the severity of OSA and nocturnal desaturation. PD-L1+ macrophages were induced by EVs from NSCLC patients with OSA and positively correlated with HIF-1α expressions. EVs from IH-treated A549 can promote PD-L1 and HIF-1α expression in macrophages and the upregulation of PD-L1 expression was reversed by specific HIF-1α inhibitor. CONCLUSION: IH can enhance the function of EVs derived from lung cancer cells to aggravate immunosuppressive status in macrophages. HIF-1α may play an important role in this process.

Effect of cigarette smoke extract on mitochondrial division in mouse quadriceps femoris cells.

BACKGROUND: To observe the effect of cigarette smoke extract (CSE) on mitochondrial division in mouse quadriceps femoris cells and to explore the potential molecular mechanism of skeletal muscle dysfunction (SMD) in patients with chronic obstructive pulmonary disease (COPD). METHODS: Quadriceps femoris were cultured, passaged, and stimulated with different concentrations of CSE. We divided cells into four groups (Control, 2.5%, 5%, 10%). The growth of cells, the expression of Dynamin related protein 1 (Drp-1), and apoptosis were observed and evaluated by fluorescence microscopy, RT-PCR, Western blot, and flow cytometry. RESULTS: The longer the intervention time, the more obvious the decrease in cell number. In the 5% and 10% groups, the cells became round with gaps. Under an inverted fluorescence microscope, the green fluorescence of cells in 5% and 10% stained with Mito-Tracker Green was significantly less than that of the Control and 2.5%. Red fluorescence was reduced and the green fluorescence was increased in the 5% and 10% stained with JC-1. Flow cytometry analysis showed that reactive oxygen species (ROS) and apoptosis were increased in the CSE intervention groups. In the Control, 2.5%, 5%, and 10%, the levels of ROS were 0.052±0.015, 0.170±0.030, 5.340±0.500, and 24.400±1.900, respectively. The apoptotic rates (%) were 0.270±0.009, 2.650±0.060, 11.850±0.020, and 31.820±1.260, respectively. The relative expression levels were, 0.900±0.093, 1.141±0.099, 1.361±0.034, 2.155±0.092 for DNM1L mRNA, and 0.509±0.008, 0.569±0.028, 0.792±0.048, 0.940±0.062 for Drp-1. There were significant differences in the apoptotic rate, and Drp-1 expression between 5% and 10% compared with the Control and 2.5% (P<0.05). CONCLUSIONS: CSE may enhance mitochondrial division of quadriceps femoris cells by up-regulating the expression of Drp-1, affecting cellular energy metabolism and promoting quadriceps femoris apoptosis, ultimately leading to the occurrence and development of skeletal muscle dysfunction in COPD.

A study on infectivity of asymptomatic SARS-CoV-2 carriers.

BACKGROUND: An ongoing outbreak of coronavirus disease 2019 (COVID-19) has spread around the world. It is debatable whether asymptomatic COVID-19 virus carriers are contagious. We report here a case of the asymptomatic patient and present clinical characteristics of 455 contacts, which aims to study the infectivity of asymptomatic carriers. MATERIAL AND METHODS: 455 contacts who were exposed to the asymptomatic COVID-19 virus carrier became the subjects of our research. They were divided into three groups: 35 patients, 196 family members and 224 hospital staffs. We extracted their epidemiological information, clinical records, auxiliary examination results and therapeutic schedules. RESULTS: The median contact time for patients was four days and that for family members was five days. Cardiovascular disease accounted for 25% among original diseases of patients. Apart from hospital staffs, both patients and family members were isolated medically. During the quarantine, seven patients plus one family member appeared new respiratory symptoms, where fever was the most common one. The blood counts in most contacts were within a normal range. All CT images showed no sign of COVID-19 infection. No severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections was detected in 455 contacts by nucleic acid test. CONCLUSION: In summary, all the 455 contacts were excluded from SARS-CoV-2 infection and we conclude that the infectivity of some asymptomatic SARS-CoV-2 carriers might be weak.

MIP-T3 Expression Associated with Defects of Ciliogenesis in Airway of COPD Patients.

Introduction. Some studies have found that cilia were shorter in COPD smokers than in nonsmokers or healthy smokers. However, the structural abnormalities of cilia and the cause of such abnormalities in COPD patients still remain unknown. Tumor necrosis factor alpha receptor 3 interacting protein 1 (MIP-T3) may play an important role in the progress of ciliary protein transporting. Objectives: This study aimed at exploring the dominated structural abnormalities of cilia and the involvement of MIP-T3 in the pathogenesis of cilia of COPD patients. Methods: Patients who accepted pulmonary lobectomy were divided into 3 groups: the chronic obstructive pulmonary disease (COPD) smoker group, the healthy smoker group, and the nonsmoker group, according to smoking history and pulmonary function. The ultrastructure of cilia and the percentage of abnormal cilia were analyzed using a transmission electron microscope. Real-time PCR, immunohistochemical staining, and western blotting in bronchial epithelium were used to determine MIP-T3 mRNA and protein expression. The relationship between the percentage of abnormal cilia and lung function and MIP-T3 protein expression was analyzed. Results: Patients in the COPD smoker group had increased percentage of abnormal cilia comparing to both the healthy smoker group and the nonsmoker group (both P values <0.05). MIP-T3 expression was significantly declined in the COPD smoker group (P values <0.05). MIP-T3 expression was significantly declined in the COPD smoker group (P values <0.05). MIP-T3 expression was significantly declined in the COPD smoker group (P values <0.05). MIP-T3 expression was significantly declined in the COPD smoker group (. Conclusions: Our results suggested that the abnormal ciliary ultrastructure, which was common in COPD patients, might be due to MIP-T3 downregulation.

Effects of Recombinant Circularly Permuted Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) (Recombinant Mutant Human TRAIL) in Combination with 5-Fluorouracil in Human Colorectal Cancer Cell Lines HCT116 and SW480.

BACKGROUND Circularly permuted tumor necrosis factor-related apoptosis-inducing ligand, a mutant form of tumor necrosis factor-related apoptosis-inducing ligand, is an effective antitumor cytokine. However, its antitumor effect in colorectal cancer is unclear. This study assessed the antitumor effect of circularly permuted tumor necrosis factor-related apoptosis-inducing ligand alone or with 5-fluorouracil in colorectal cancer cells in vitro and explored the underlying mechanisms. MATERIAL AND METHODS We used the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assay to analyze cell proliferation inhibition. The apoptotic effects of circularly permuted tumor necrosis factor-related apoptosis-inducing ligand, 5-fluorouracil, or both in human colorectal cancer cells were evaluated using flow cytometry. Furthermore, the levels of apoptosis-related proteins were examined by Western blotting. RESULTS Compared to either agent alone, cotreatment with 5-fluorouracil and circularly permuted tumor necrosis factor-related apoptosis-inducing ligand showed obvious antitumor effects and induced significant apoptosis of colorectal cancer cells. 5-Fluorouracil enhanced circularly permuted tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis by increasing death receptor 4 and 5 levels in HCT116 cells, but only of death receptor 4 in SW480 cells. Moreover, 5-fluorouracil plus circularly permuted tumor necrosis factor-related apoptosis-inducing ligand increased apoptosis-related protein levels such as cleaved caspase-3, caspase-8, and poly-ADP-ribose polymerase and downregulated that of the survival protein B-cell lymphoma-extra-large. Pretreatment with the pan-caspase inhibitor, z-VAD-FMK, attenuated the caspase-dependent apoptosis induced by circularly permuted tumor necrosis factor-related apoptosis-inducing ligand alone or combined with 5-fluorouracil. CONCLUSIONS Cotreatment with 5-fluorouracil and circularly permuted tumor necrosis factor-related apoptosis-inducing ligand showed enhanced antitumor effects on colorectal cancer cells.

A Phase1b Dose Escalation Study of Recombinant Circularly Permuted TRAIL in Patients With Relapsed or Refractory Multiple Myeloma.

OBJECTIVES: Circularly permuted tumor necrosis factor-related apoptosis-inducing ligand (CPT), or CPT, is a novel antitumor drug candidate. This phase 1b study evaluated the safety, tolerability, pharmacokinetics (PK), and efficacy of single-agent CPT in patients with relapsed or refractory multiple myeloma (RRMM), and aimed to identify the recommended dose for the phase 2 study. MATERIALS AND METHODS: Patients received single or multiple doses (once daily for 5 consecutive days per 21-d cycle) of CPT intravenous infusion at doses of 5, 6.5, 8, 10, and 15 mg/kg, to determine the maximum tolerated dose, dose-limiting toxicities, safety, and tolerability. PK were evaluated. Preliminary efficacy was assessed after each treatment cycle. RESULTS: Twenty-nine RRMM patients received CPT. Neither the dose-limiting toxicity nor the maximum tolerated dose were identified. The most common treatment-related adverse events were liver enzyme elevations (eg, elevation of aspartate aminotransferase and alanine aminotransferase), hematological abnormalities (eg, leukopenia and neutropenia), fever, fatigue, and vomiting. CPT had a terminal half-life of 0.90 to 1.27 hours at the 5 dose levels, and no accumulation was observed with repeated doses. Safety and PK profiles were similar across the 5 dose cohorts. The overall response rate (complete and partial response) was 18.5%. The clinical benefit rate (complete, partial, and minimal response) was 33.3%. Sixteen patients did not respond to CPT (no change and progressive disease). Patients treated with higher doses of CPT appeared to have better responses. CONCLUSIONS: CPT was safe and well tolerated by RRMM patients, and doses between 8 and 15 mg/kg were recommended for the phase 2 study.