[Application of discrete event simulation model in analysis on cost-effectiveness of epidemiology screening]

Discrete event simulation (DES) model is based on individual data, by which discrete events over time are simulated to reflect disease progression. The effects of individual characteristics on disease progression could be considered in the DES model. Moreover, unlike state-transition models, DES model without setting of fixed cycle can contribute to more accurate estimation of event time, especially in the evaluation of the long-term effectiveness of screening strategies for complex diseases in which time dimension needs to be considered. This article introduces the general principles, construction steps, analytic methods and other relevant issues of the DES model. Based on a research case of estimating the cost-effectiveness of screening for abdominal aortic aneurysms in women aged 65 years and above in the United Kingdom, key points in applications of the DES model in analysis on effectiveness of complex disease screening are discussed in detail, including model construction and analysis and interpretation of the results. DES model can predict occurring time of discrete events accurately by establishing the distribution function of their occurring time and is increasingly used to evaluate the screening strategies for complex diseases in which time dimension needs to be considered. In the construction of DES model, it is necessary to pay close attention to the clear presentation of model structure and simulation process and follow the relevant reporting specification to conduct cost-effectiveness analysis to ensure the transparency and repeatability of the research.

Activation cross sections for reactions induced by 14 MeV neutrons on natural titanium

Cross sections for the neutrons around 14 MeV interaction with natural titanium were precisely measured by neutron activation and off-line measurement technique. The fast neutrons were produced by ³H(d,n)⁴He reaction and the neutron energy was obtained by using the cross section ratio method of ⁹⁰Zr(n,2n)⁸⁹Zr to ⁹³Nb(n,2n)^92mNb reactions. Experimental cross sections have been acquired for ^natTi(n,x)⁴⁶Sc, ^natTi(n,x)⁴⁷Sc, ⁵⁰Ti(n,x)⁴⁷Ca and ⁴⁸Ti(n,x)⁴⁸Sc reactions. The measured cross section data are compared with the experimental data available in the previous literature and evaluated nuclear data from the ENDF/B-VIII.0, JEFF-3.3, JENDL-5, BROND-3.1, CENDL-3.2 and FENDL-3.2b libraries. Furthermore, excitation functions for these reactions were calculated by using the theoretical model based on Talys-1.96 code with default and adjusted parameters. Within experimental error, evaluated nuclear data are mostly consistent with experimental data. The excitation function with adjusted parameters can roughly reproduce the experimental data.

Remediation of industrial site soil contaminated with PAHs using stage persulfate oxidation activated by Fe2+ chelated with sodium citrate

The remediation for industrial site soil has attracted public concerns because of the hazardous and hydrophobic properties of organic pollutants existed in the soil. The persulfate oxidation activated by Fe²⁺ chelated with sodium citrate (PS/Fe²⁺/SC) was used to remediate different types of industrial site soils in the present study. The maximum removal rates of Σ16 PAHs in the Nanjing site soil (NJS) and Hefei site soil (HFS) were 73.6% and 85.8% after the second-stage oxidation, respectively. The late oxidation stages couldn't enhance the degradation efficiency of PAHs due to the increase of high crystalline Fe mineral phases both in the NJS and HFS, which significantly decreased the Fe²⁺/Fe³⁺ recycle and further inhibited the reactive oxygen species production during the remediation. The remediation using PS/Fe²⁺/SC could change the soil physicochemical properties, such as the functional groups, specific surface area (SSA), total pore volume (TPV) and some UV spectral parameters of soil particles. Additionally, the oxidation of PS/Fe²⁺/SC also altered the composition of soil dissolve organic matters, especially the fulvic acid, which further affected the Fe²⁺ oxidation. The study mainly discloses the mechanism of limitation using persulfate oxidation activated by Fe materials at late oxidation stage.

Nomogram Based on Clinical and Radiomics Data for Predicting Radiation-induced Temporal Lobe Injury in Patients with Non-metastatic Stage T4 Nasopharyngeal Carcinoma

AIMS

To use pre-treatment magnetic resonance imaging-based radiomics data with clinical data to predict radiation-induced temporal lobe injury (RTLI) in nasopharyngeal carcinoma (NPC) patients with stage T4/N0-3/M0 within 5 years after radiotherapy.

MATERIALS AND METHODS

This study retrospectively examined 98 patients (198 temporal lobes) with stage T4/N0-3/M0 NPC. Participants were enrolled into a training cohort or a validation cohort in a ratio of 7:3. Radiomics features were extracted from pre-treatment magnetic resonance imaging that were T1-and T2-weighted. Spearman rank correlation, the t-test and the least absolute shrinkage and selection operator (LASSO) algorithm were used to select significant radiomics features; machine-learning models were used to generate radiomics signatures (Rad-Scores). Rad-Scores and clinical factors were integrated into a nomogram for prediction of RTLI. Nomogram discrimination was evaluated using receiver operating characteristic analysis and clinical benefits were evaluated using decision curve analysis.

RESULTS

Participants were enrolled into a training cohort (n = 139) or a validation cohort (n = 59). In total, 3568 radiomics features were initially extracted from T1-and T2-weighted images. Age, D_max, D_1cc and 16 stable radiomics features (six from T1-weighted and 10 from T2-weighted images) were identified as independent predictive factors. A greater Rad-Score was associated with a greater risk of RTLI. The nomogram showed good discrimination, with a C-index of 0.85 (95% confidence interval 0.79-0.92) in the training cohort and 0.82 (95% confidence interval 0.71-0.92) in the validation cohort.

CONCLUSION

We developed models for the prediction of RTLI in patients with stage T4/N0-3/M0 NPC using pre-treatment radiomics data and clinical data. Nomograms from these pre-treatment data improved the prediction of RTLI. These results may allow the selection of patients for earlier clinical interventions.

PD-L1 Expression in Cytological and Histological Lung Cancer Specimens

Introduction/Objective

Several studies have explored the feasibility of measuring PD-L1 in cell block cytology and indicated cytological materials could be a reliable source for PD-L1 evaluation in non-small cell lung carcinoma patients. A few studies have investigated the compatibility and performance of PD-L1 clone SP263 testing between cytology and histology specimens. The study was pursued to evaluate PD-L1 expression in cell blocks from EBUS- TBNA compared to that in biopsied tissues from patients with lung carcinoma in our institution to evaluate a feasibility of PD-L1 clone SP263 in cell blocks and histology samples.

Methods/Case Report

A total of 57 specimens cytologically diagnosed lung carcinoma using endobronchial ultrasound guided transbronchial needle aspiraton (EBUS-TBNA) from Jan 1st, 2020, to Dec 31st, 2021 were screened for enrollment. Among them, 24 patients diagnosed with lung carcinoma using EBUS-TBNA and matched transbronchial biopsy (TBB) specimens were reviewed for study. After careful selection, 13 paired formalin-fixed tissues from lung carcinoma patients, including cell blocks and matched histology samples, were included. PD-L1 expression was assessed using the SP263 assay, and the tumor proportion score (TPS) was evaluated. PD-L1 expression was finally divided into three categories according to the TPS: < 1% (negative), 1–49% (low expression) and ≥ 50% (high expression).

Results (if a Case Study enter NA)

Of the 13 matched pairs, 12 (92.3%) showed concordant PD-L1 expression. On cytology, 3 cases were positive (2 high expressors and 1 low- expressors) of which 2 were concordant and 1 discordant with matched histology specimens. Ten cytology samples were negative for PD-L1 expression, and they were concordant to histology samples. The correlation coefficient for TPS was 0.75 considered as having good value. Conclusion: With an overall concordance rate of 92.3% between cytology and histology specimen, this study demonstrates the feasibility of PD-L1 IHC with SP263 clone on limited quality and quantity of cytology samples from lung carcinoma in our institute. It is required for further evaluation with additional specimens to conclude that the usefulness of cytology cell blocks for PD-L1 expression analysis.

[Safety and efficacy of a new domestic distal perforated stent graft in the treatment of Stanford type B aortic dissection]

Objective: To evaluate the safety and efficacy of a new domestic distal perforated stent graft (Talos stent) in the treatment of Stanford type B aortic dissection (TBAD). Methods: Twenty-five patients with TBAD treated with Talos stent in Yan'an Hospital Affiliated to Kunming Medical University from February 2018 to December 2019 were selected as the research subjects. Intraoperative angiography was performed to determine the number of branch arteries that remained after stent release. On postoperative day 5 (POD5), the pain intensity of the patients was evaluated by visual analog scale (VAS). The computed tomography angiography (CTA) of the patients before operation, 6 months and 12 months after operation were compared including aortic diameter, true lumen diameter, and false lumen diameter at the level of tracheal bifurcation. Follow-up was performed 1 month, 6 months, 12 months, and 24 months after surgery, and the occurrence of stent-related adverse events, reoperation and survival rate were recorded. Results: The enrolled patients included 19 males and 6 females, aged (52.6±11.1) years. Intraoperative angiography showed that 4 (1, 7) branch arteries were preserved, and the VAS score was 1 (0, 1) on POD5. The aortic diameters at the level of the tracheal bifurcation were (34.9±1.1) mm, (34.6±0.9) mm and (34.8±1.0) mm before surgery, 6 months and 12 months after surgery, and there was no significant difference (P=0.926); the diameters of the main true lumen at the level of the tracheal bifurcation were (13.3±1.6) mm, (21.8±1.0) mm and (22.3±1.1) mm before surgery, 6 months and 12 months postoperatively, while the diameters of the main false lumen at the level of the tracheal bifurcation were (20.8±2.2) mm, (4.5±1.5) mm, and (4.6±1.7) mm, respectively. Compared with before surgery, the diameter of true lumen increased significantly 6 months and 12 months after surgery (both P<0.001), while the diameter of false lumen decreased (both P<0.001). No stent-related adverse events occurred within 30 days after surgery, no secondary operations occurred within 12 months after surgery, no type Ⅰ and type Ⅲ endoleaks, no deaths or cases of paraplegia were reported, and the stent structure and position remained good. There were no deaths or paraplegia cases 24 months postoperatively, and no stent-related adverse events occurred. Conclusion: Using Talos stent in the treatment of TBAD can effectively help remodel the aorta, while preserve the intercostal artery and spinal artery, with good clinical effect and safety.

PPCPs and heavy metals from hydrothermal sewage sludge-derived biochar: migration in wheat and physiological response

Once the sludge was directly used in the farmland, it will have a negative impact on human health through the food chain because sludge contains pollutants. Sewage sludge pyrolysis into biochar is an effective way to realize sludge harmless and resourceful utilization. This research used hydrothermal carbonization method to convert sludge into sludge biochar (SLBC) to reduce the types and contents of pharmaceuticals and personal care products (PPCPs) and available heavy metals. Furthermore, migration of the residual caffeine (Caf), acetaminophen (Ace), and heavy metals (Cr, Pb, Cu, Zn) released from the SLBC in the wheat was assessed. The results showed that the levels of Caf, Ace, Pb, Cu, and Zn accumulated in the shoots were lower than the limit regulated by Drug and Food Additive Use Standard in China (Caf: 150 mg/kg; Ace: 2.5 ~ 5 mg/kg; Pb: 0.3 mg/kg; Cu: 10 mg/kg; Zn: 20 mg/kg). The migration of Cr from roots to shoots was also significantly controlled by SBLC. SBLC delayed the germination time of wheat seeds with increasing in hydrothermal temperature, the germination rate and root length showed a decreasing trend. Evans blue and O₂^- fluorescence staining of root tips also confirmed this conclusion. When the wheat was exposed to the low temperature and dose of SLBC, the chlorophyll contents and growth of wheat can be significantly increased; the oxidative damage of cell plasma membrane and net photosynthetic rate were reduced. However, 0.8 g/L of SLBC made plants suffer abiotic stress and caused oxidative damage to plants, and decreased membrane system stability. The study provides some parameters for sludge to realize resource utilization in the agricultural system.

[Clinical characteristics and outcomes of acute respiratory distress syndrome caused by severe Chlamydia psittaci pneumonia]

Objective: To investigate the clinical characteristics and outcomes of acute respiratory distress syndrome (ARDS) caused by Chlamydia psittaci pneumonia. Methods: From June 2016 to January 2021, 10 cases were diagnosed as severe Chlamydia psittaci pneumonia induced ARDS in Intensive Care Unit of Respiratory and Critical Care Medicine Department (RICU) of Beijing Chao-Yang Hospital Affiliated to Capital Medical University. We collected the clinical data including clinical features, laboratory tests, imaging and outcomes of the patients. Results: The pathogenic diagnosis was confirmed by metagenomic Next-generation Sequencing (mNGS) in these 10 patients, with a median age of 59 (46, 67) years. In addition to high fever, cough and dyspnea, the patients also had multiple organ involvement. Six patients had elevated peripheral leukocyte count, 10 cases had increased type B natriuretic peptide, 7 cases had increased aspartate aminotransferase/alanine aminotransferase, 9 cases had hyponatremia and 3 cases had elevated creatinine. The imaging findings were bilateral consolidation with air bronchogram and infiltrates, and pleural effusion were found in 5 cases. All cases were combined with respiratory failure. Six patients received invasive mechanical ventilation. Nine patients received moxifloxacin and one patient was administrated with Azithromycin. All the patients were improved and discharged after the treatment, and the mean duration of RICU stay was 13.5 (11, 16.7) days. One month follow-up of nine patients showed significant improvement in lung lesions. Conclusions: Severe Chlamydia psittiaci pneumonia may be complicated with respiratory failure and/or multiple organ involvement. For severe pneumonia with an exposure history of sick birds, the possibility of Chlamydia psittaci infection should be considered. mNGS may help etiological diagnosis. All patients in this study had a good prognosis after targeted treatment.

[Exosomal FZD10 derived from non-small cell lung cancer cells promotes angiogenesis of human umbilical venous endothelial cells in vitro]

OBJECTIVE

To investigate the effect of exosomal FZD10 derived from non-small cell lung cancer (NSCLC) cells on angiogenesis of human umbilical venous endothelial cells (HUVECs) and explore the possible mechanism.

METHODS

We analyzed the expression of FZD10 in two NSCLC cell lines (95D and H1299 cells), normal human bronchial epithelial cells (BEAS-2B cells) and their exosomes isolated by ultracentrifugation. Cultured HUVECs were treated with the exosomes derived from NSCLC cells or NSCLC cells transfected with FZD10-siRNA, and the changes in tube formation ability of the cells were analyzed using an in vitro angiogenesis assay. ELISA was performed to determine the concentration of VEGFA and Ang-1 in the conditioned media of HUVECs, and RT-qPCR was used to analyze the mRNA levels of VEGFA and Ang-1 in the HUVECs. The effects of exosomal FZD10 on the activation of PI3K, Erk1/2 and YAP/TAZ signaling pathways were evaluated using Western blotting.

RESULTS

Compared with BEAS-2B cells and their exosomes, 95D and H1299 cells and their exosomes all expressed high levels of FZD10 (P < 0.01). The exosomes derived from 95D and H1299 cells significantly enhanced tube formation ability and increased the expressions of VEGFA and Ang-1 protein and mRNA in HUVECs (P < 0.01), but FZD10 knockdown in 95D and H1299 cells obviously inhibited these effects of the exosomes. Exosomal FZD10 knockdown suppressed the activation of PI3K and Erk1/2 signaling pathways, but had no obvious effect on the activation of YAP/TAZ signaling pathway.

CONCLUSION

Exosomal FZD10 derived from NSCLC cells promotes HUVEC angiogenesis in vitro, the mechanism of which may involve the activation of PI3K and Erk1/2 signaling pathways.

[Predictive value of serum HBV RNA for therapeutic effect of entecavir in patients with chronic hepatitis B]

OBJECTIVE

To investigate the value of HBV RNA for predicting the therapeutic effect of long-term entecavir (ETV) antiviral therapy in patients with chronic hepatitis B (CHB).

METHODS

Serum samples were collected from 59 CHB patients treated with ETV for 96 or 108 months. HBV RNA levels, HBV DNA levels, and serological marker (HBeAg) levels were measured at baseline and 3, 6, 9, 12, 36, 72, and 96 (or 108) months during the therapy.

RESULTS

Although HBV RNA level decreased after 12 and 36 months of ETV antiviral therapy, no significance changes occurred in HBV RNA negative conversion rate (P>0.05). After 72 months of treatment or longer, 33 patients had HBV RNA levels lower than 100 copies/mL, and among them 29 patients had HBV RNA levels lower than the detection limit, and HBV RNA negative conversion rate was statistically significant (P < 0.05). A lower HBV RNA level was associated with a higher HBeAg negative conversion rate (P < 0.05). Age and HBV RNA level were positively correlated with HBeAg negative conversion rate (P < 0.05).

CONCLUSION

Prolonged ETV antiviral therapy results in better clearance of HBV RNA and a higher negative conversion rate in CHB patients. The length of antiviral therapy and age are positively correlated with the negative conversion rate of HBV RNA, and earlier administration of the antiviral treatment achieves better therapeutic effect. Serum HBV RNA level can be used as an indicator for predicting conversion to negative HBeAg in CHB patients receiving ETV therapy.

[Accuracy of the China-PAR and WHO risk models in predicting the ten-year risks of cardiovascular disease in the Chinese population]

Objective: To externally validate and compare the accuracy of the China-PAR (Prediction for ASCVD Risk in China) model and the 2019 World Health Organization (WHO) cardiovascular disease risk charts for East Asian in predicting a 10-year cardiovascular disease in a general Chinese population. Methods: Participants aged 40-79 years without prior cardiovascular disease at baseline in the CHinese Electronic health Records Research in Yinzhou (CHERRY) were analyzed. The Kaplan-Meier analysis estimated the observed cardiovascular events (including non-fatal myocardial infarction, fatal coronary heart disease, and non-fatal or fatal stroke) rate within ten years. The expected risks were calculated using the WHO risk charts for East Asia (including the laboratory-based and non-laboratory-based models) and the China-PAR model. The expected-observed ratios were calculated to evaluate the overestimation or underestimation of the models in the cohort. Model accuracy was assessed by discrimination C-index, calibration χ² value, and calibration plots. Results: During a median of 7.26 years of follow-up, 13 301 cardiovascular events were identified among 225 811 participants. The C-index for the China-PAR model, WHO laboratory-based model and WHO non-laboratory-based model were 0.741 (0.735-0.747), 0.747 (0.740-0.753), and 0.739 (0.733-0.746) for men, and 0.782 (0.776-0.788), 0.789 (0.783-0.795), and 0.782 (0.776-0.787) for women, respectively. The WHO laboratory-based model and non-laboratory-based model underestimated the 10-year ASCVD risk by around 15% in women and underestimated by 0.8% and 4.4% in men, respectively. The China-PAR model underestimated the risks by 19.5% and 42.3% for men and women. Conclusions: The China-PAR and WHO models all have pretty good discriminations for 10-year cardiovascular risk assessment in this general Chinese population. However, the accuracy should be improved in the highest-risk groups, suggesting further specific models are still needed for those with the highest risk, such as patients with diabetes or older persons.

[Effectiveness of statin treatment strategies for primary prevention of cardiovascular diseases in a community-based Chinese population: A decision-analytic Markov model]

OBJECTIVE

To evaluate the effectiveness of statin treatment strategies based on risk assessment for the primary prevention of cardiovascular diseases by the Western guidelines in a community-based Chinese population from economically developed areas using data from the Chinese electronic health records research in Yinzhou (CHERRY) study.

METHODS

A Markov model was used to evaluate the effectiveness of the following statin treatment strategies, including: (1) usual care without cardiovascular risk assessment(Strategy 0); (2) using the World Health Organization (WHO) non-laboratory-based risk charts with statin treatment for high-risk group (risk ≥ 20%) (Strategy 1); (3) using the WHO laboratory-based risk charts with statin treatment for high-risk group (risk ≥ 20%) (Strategy 2); and (4) using the Prediction for Atherosclerotic cardiovascular disease Risk in China (China-PAR) model with statin treatment for high-risk group (risk ≥ 10%, Strategy 3). According to the guidelines, adults in the medium-risk group received lifestyle intervention, and adults in the high-risk group received life-style intervention and statin treatment under these strategies. The Markov model simulated different strategies for ten years (cycles) using parameters from the CHERRY study, published data, meta-analyses and systematic reviews for Chinese. The number of cardiovascular events or deaths, as well as the number need to treat (NNT) with statin per cardiovascular event or death prevented, were calculated to compare the effectiveness of different strategies. One-way sensitivity analysis on the uncertainty of incidence rate of cardiovascular diseases, and probabilistic sensitivity analysis on the uncertainty of hazard ratios of interventions were conducted.

RESULTS

Totally 225 811 Chinese adults aged 40-79 years without cardiovascular diseases at baseline were enrolled. In contrast to the usual care without risk assessment-based statin treatment strategy, Strategy 1 using the WHO non-laboratory-based risk charts could prevent 3 482 [95% uncertainty interval (UI): 2 110-4 661] cardiovascular events, Strategy 2 using the WHO laboratory-based risk charts could prevent 3 685 (95%UI: 2 255-4 912) events, and Strategy 3 using the China-PAR model could prevent 3 895 (95%UI: 2 396-5 181) events. NNTs with statin per cardiovascular event prevented were 22 (95%UI: 14-54), 21 (95%UI: 14-52), and 27 (95%UI: 17-67), respectively. Strategy 3 could prevent more cardiovascular events, while Strategies 1 and 2 required fewer numbers need to treat with statin per cardiovascular event prevented. The results were consistent in the sensitivity analyses.

CONCLUSION

The statin treatment strategies based on risk assessment for the primary prevention of cardiovascular diseases recommended by the Western guidelines could achieve substantive health benefits in adults from developed areas of China. Using the China-PAR model for cardiovascular risk assessment could prevent more cardiovascular diseases while using the WHO risk charts seems more efficient.

[Applications of the NDR and DIAL models for risk prediction on cardiovascular disease in patients with type 2 diabetes in Ningbo]

Objective: To validate the performance of cardiovascular risk prediction models based on the Sweden National Diabetes Register (NDR) and Diabetes Lifetime-perspective prediction (DIAL) model for assessing risks of 5-year and 10-year cardiovascular disease (CVD) among Chinese patients with type 2 diabetes. Methods: Based on the Chinese Electronic Health Records Research in Yinzhou study, 83 503 patients with type 2 diabetes aged 30-75 years without a history of CVD at baseline were included from January 1, 2010 to December 31, 2020. Recalibrated NDR model was used to estimate 5-year risk, while the recalibrated DIAL model was used to predict 5-year and 10-year risks. The competing events adjusted Kaplan-Meier analysis was used to obtain the observed cardiovascular events. Discrimination C statistics evaluated model accuracy, calibration χ² value, and calibration plots. Results: Through a median follow-up of 7.0 years, 7 326 cardiovascular events, and 2 937 non-vascular deaths were identified among a total of 83 503 subjects. The recalibrated NDR model overestimated 5-year risk by 39.4% in men and 8.6% in women, whereas the overestimation for the recalibrated DIAL model was 14.6% in men and 50.1% in women. The DIAL model had a better discriminative ability (C-statistic=0.681, 95%CI: 0.672-0.690) than NDR model (C-statistic=0.667, 95%CI: 0.657-0.677) in 5-year risk prediction for men, and the models had a similar ability for women (C-statistic=0.699, 95%CI: 0.690-0.708 for NDR and C-statistic=0.698, 95%CI: 0.689-0.706 for DIAL). The prediction accuracy of the DIAL model was improved in the 10-year risk, with the underestimation being 1.6% for men and the overestimation being 12.8% for women. Conclusions: Both recalibrated NDR and DIAL models overestimated 5-year cardiovascular risk in Chinese patients with type 2 diabetes, while the higher overestimation was shown using the DIAL model. However, the improvement was found in predicting 10-year CVD risk using the DIAL model, which suggested the value of lifetime risk prediction and indicated the need for research on the lifetime risk prediction model for cardiovascular risk assessment in Chinese patients with type 2 diabetes.

[Applications of microsimulation model for cost-effectiveness analysis on screening in epidemiology]

Microsimulation model simulates individuals and estimates transition probabilities within the population using individual participant data. This approach could deal with the heterogeneous characteristics among the people or personal history of diseases and may be relevant in addressing cost-effectiveness problems of screening for complex conditions in epidemiology. This paper introduces the general principles, basic steps involved in implementation, analytic methods, and other related issues of the microsimulation model. Based on a practical research case of estimating the cost-effectiveness of microalbuminuria screening for chronic kidney disease in the United States, critical points in applications of the microsimulation model for cost-effectiveness analysis of screening were discussed in detail, including model development, model analysis, and the interpretation of the results. The microsimulation model considers the dynamic nature of complex diseases by estimating a broad range of individual characteristics and increasingly used to provide insights into complex problems that the Markov model does not efficiently address. For better supporting evidence-informed decision-making in public health, future studies should be aware of the accuracy of parameters in the decision-analytic model and the transparency of the models and results, as well as complying with the relevant reporting standards.

OP0081 IL-13 REDUCES BONE EROSION IN RHEUMATOID ARTHRITIS BY UP-REGULATING OPG IN SYNOVIAL FIBROBLASTS

Background

Bone erosion in rheumatoid arthritis (RA) is partly caused by excessive activation of osteoclasts[1]. Osteoclasts can be derived from RA synovium and their differentiation can be inhibited by OPG, a decoy receptor of the osteoclastogenesis promoting cytokine RANKL[2,3]. Fibroblast-like synoviocytes (FLSs) are a main type of stromal cells in the synovium that can secret OPG[4]. The OPG secretion by FLSs can be modulated by various cytokines[5]. Interleukin (IL)-13 is a cytokine rich in early RA synovial fluid and it decreases as RA progresses[6]. IL-13 was reported to alleviate bone erosion in RA mouse models[7]. However, how IL-13 reduces bone destruction remains unclear.

Objectives

To investigate if IL-13 can inhibit osteoclast differentiation by up-regulating OPG in FLSs of RA patients (RA-FLSs), thus reduces bone erosion in RA.

Methods

FLSs were isolated from the synovium tissue of RA patients with informed consent who underwent joint replacement surgery (Ethics No. 2021-544-01). OPG and RANKL expression by RA-FLSs were evaluated by qRT-PCR. OPG secretion was determined by ELISA. Western blot was performed to analyze OPG expression and the activation of STAT6 pathway. IL-13 and OPG siRNA pre-treated RA-FLSs conditioned medium were used in osteoclast induction to test if IL-13 can inhibit osteoclastogenesis by up-regulating OPG in RA-FLSs. Micro-CT scanning and immunofluorescence were done to determine if IL-13 can induce OPG expression and alleviate bone erosion in vivo.

Results

IL-13 can significantly upregulate OPG expression and secretion by RA-FLSs. Meanwhile, RANKL/OPG ratio was downregulated (Figure 1A). STAT6 phosphorylation and OPG upregulation of RA-FLSs by IL-13 can be significantly inhibited by a STAT6 inhibitor (inh.) (Figure 1B). IL-13 receptor α1 (IL-13Rα1) and IL-13 receptor α2 (IL-13Rα2) knockdown can inhibit OPG upregulation by IL-13 in RA-FLSs, indicating that IL-13 can induce OPG secretion in RA-FLSs through IL-13Rα1 and IL-13Rα2 via STAT6 pathway (Figure 1C). 20% conditioned medium of RA-FLSs pretreated by IL-13 can significantly inhibited osteoclast differentiation in vitro. OPG knockdown in RA-FLSs significantly reversed the inhibition, indicating that IL-13 inhibits osteoclastogenesis by upregulating OPG in RA-FLSs (Figure 1D). In collagen-induced arthritis mice, IL-13 injection can reduce bone destruction in the ankle joint. Meanwhile, OPG expression in vemintin positive FLSs was increased (Figure 1E and F).

Figure 1.

Conclusion

IL-13 can inhibit osteoclastogenesis by up-regulating OPG in RA-FLSs through IL-13 receptors via STAT6 pathway, thus ameliorate bone erosion in RA.

References

[1]Schett G, Gravallese E. Bone erosion in rheumatoid arthritis: mechanisms, diagnosis and treatment. Nat Rev Rheumatol 2012;8(11):656-64.

[2]Walsh MC, Choi Y. Biology of the RANKL-RANK-OPG System in Immunity, Bone, and Beyond. Front Immunol 2014;5:511.

[3]Gravallese EM, Harada Y, Wang JT, et al. Identification of cell types responsible for bone resorption in rheumatoid arthritis and juvenile rheumatoid arthritis. Am J Pathol 1998;152(4):943-51.

[4]Ziolkowska M, Kurowska M, Radzikowska A, et al. High levels of osteoprotegerin and soluble receptor activator of nuclear factor kappa B ligand in serum of rheumatoid arthritis patients and their normalization after anti-tumor necrosis factor alpha treatment. Arthritis Rheum 2002;46(7):1744-53.

[5]Tunyogi-Csapo M, Kis-Toth K, Radacs M, et al. Cytokine-controlled RANKL and osteoprotegerin expression by human and mouse synovial fibroblasts: fibroblast-mediated pathologic bone resorption. Arthritis Rheum 2008;58(8):2397-408.

[6]Raza K, Falciani F, Curnow SJ, et al. Early rheumatoid arthritis is characterized by a distinct and transient synovial fluid cytokine profile of T cell and stromal cell origin. Arthritis Res Ther 2005;7(4):R784-95.

[7]Woods JM, Amin MA, Katschke KJ, Jr., et al. Interleukin-13 gene therapy reduces inflammation, vascularization, and bony destruction in rat adjuvant-induced arthritis. Hum Gene Ther 2002;13(3):381-93.

Acknowledgements

This study was supported by the National Natural Science Foundation of China (grant number 81671608). We would like to thank Prof. Zhihong Xu and Dr. Minghui Sun for the assistance in synovial tissue collection, and all the patients and participants for their support for our study.

Disclosure of Interests

None declared.

AB0096 MECHANISM OF SHIP IN NEUTROPHIL EXTRACELLULAR TRAP IN RHEUMATOID ARTHRITIS

Background

Rheumatoid arthritis（RA） is a common autoimmune disease with unknown etiology. RA is characterized by the destruction of cartilage and bone. Neutrophils are abundant in synovial fluid of RA and are closely related to the development of RA 1。In recent years, it has been reported that neutrophils can release neutrophil extracellular traps（NET）, which can not only kill different bacteria and viruses, but also closely related to autoimmune diseases 1,2 Studies have shown that NET is involved in the development of RA3. The Src homologous 2 domain containing inositol 5-phosphatase 1 (SHIP-1) controls the level of intracellular inositol 3-phosphate kinase product phosphatidylinositol-3,4,5-triphosphate. SHIP can be used as a positive or negative regulatory signal in different stimuli.And So has studied that the inflammation of CIA mouse model is reduced after SHIP is inhibited.

Objectives

Therefore, we want to study whether SHIP is involved in the formation of rheumatoid arthritis NET and its relationship with NET.

Methods

We isolated neutrophils from RA peripheral blood, stimulated NETosis with PMA, and detected the changes of NETosis in the group with SHIP inhibitor by flow cytometry and immunofluorescence. In addition, DBA mice were divided into three groups: HC, CIA and SHIP inhibitor intraperitoneal injection group. The degree of paw swelling and HE staining were used to detect the inflammation of mice, and the release of NET in CIA model was detected by flow cytometry.

Results

In the DBA model, the generation of neutrophil extracellular traps decreased significantly in the intraperitoneal injection group of SHIP inhibitor. SHIP inhibitor can significantly inhibit the formation of NET in RA patients. In addition, we also found TNF- α Monoclonal antibodies reduced NETosis in RA patients, while SHIP inhibitors inhibited the generation of NET in RA patients. The results suggest that SHIP may inhibit the inflammatory factor TNF- α. In turn, it is involved in the release of NET in rheumatoid arthritis

Conclusion

SHIP participates in the formation of NET in rheumatoid arthritis and affects the production of NET through pro-inflammatory cytokines. Therefore, SHIP is expected to become a new target for the treatment of RA.

References

[1]Skopelja-Gardner, S.; Jones, J. D.; Rigby, W. F. C. “NETtling” the Host: Breaking of Tolerance in Chronic Inflammation and Chronic Infection. J. Autoimmun.2018, 88, 1–10. https://doi.org/10.1016/j.jaut.2017.10.008.

[2]Lee, K. H.; Kronbichler, A.; Park, D. D.-Y.; Park, Y.; Moon, H.; Kim, H.; Choi, J. H.; Choi, Y.; Shim, S.; Lyu, I. S.; Yun, B. H.; Han, Y.; Lee, D.; Lee, S. Y.; Yoo, B. H.; Lee, K. H.; Kim, T. L.; Kim, H.; Shim, J. S.; Nam, W.; So, H.; Choi, S.; Lee, S.; Shin, J. I. Neutrophil Extracellular Traps (NETs) in Autoimmune Diseases: A Comprehensive Review. Autoimmun. Rev.2017, 16 (11), 1160–1173. https://doi.org/10.1016/j.autrev.2017.09.012.

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Disclosure of Interests

None declared

Bactericidal efficacy of low concentration of vaporized hydrogen peroxide with validation in a BSL-3 laboratory

BACKGROUND

Highly infective pathogens are cultured and studied in biosafety laboratories. It is critical to thoroughly disinfect these laboratories to prevent laboratory infection. A whole-room, non-contact, reduced corrosion disinfection strategy using hydrogen peroxide was proposed and evaluated.

AIM

To evaluate the bactericidal efficacy of 8% and 10% vaporized hydrogen peroxide( VHP) in a laboratory setting with spores and bacteria as bioindicators.

METHODS

Spores of B. atrophaeus and B. stearothermophilus, along with bacteria E. coli, S. aureus, and S. epidermidis were placed in pre-selected locations in a sealed laboratory and an OXY-PHARM NOCOSPRAY2 vaporized hydrogen peroxide generator was applied. Spore killing efficacy was qualitatively evaluated, and bactericidal efficacy was quantitatively analyzed, and the mean log10 reduction was determined. Finally, the optimized disinfection strategy was verified in a BSL-3 laboratory.

FINDINGS

Significant reductions in microbial load were obtained for each of the selected spores and bacteria when exposed to VHP in concentrations of 8% and 10% for 2～3 h. S. aureus was found to be more resistant than E. coli and S. epidermidis. Tests with 8% hydrogen peroxide and exposure for more than 3 h completely killed B. atrophaeus on surfaces and equipment in the BSL-3 laboratory.

CONCLUSION

The vaporized hydrogen peroxide generator is superior in terms of good diffusivity and low corrosiveness and is time-effective in removing the disinfectant residue. This study provides reference for the precise disinfection of air and object surfaces in biosafety laboratories under varying conditions.

Earthworms' Degradable Bioplastic Diet of Polylactic Acid: Easy to Break Down and Slow to Excrete

Microplastics (MPs) in soils may be ingested by terrestrial animals. While the application of bioplastics is increasing, the ingestion and excretion characteristics of bio-MPs by terrestrial animals are poorly understood as compared to fossil-MPs. Here, the approach-avoidance behavior of adult earthworms Eisenia fetida to MP-contaminated soil was assessed. Fossil-based poly(ethylene terephthalate) (PET) and bio-based poly(lactic acid) (PLA) MPs were found to be preferred by the earthworms, which might be due to the odor of polymer monomers. MPs in earthworm casts were analyzed by microscopy counting and liquid chromatography-tandem mass spectrometry. The amount of microscopically recognizable excreted PET and PLA was 553 and 261 items/g, respectively, while a higher proportion of smaller PLA particles also presented. Bio-based PLA is much easy to break down by earthworms than fossil-based PET. Submicron and nanocron PLA accounted for 57 and 13% of the excreted PLA on the 10th day of excretion. MP excretion was well described with the first-order kinetic model, and the elimination half-life was 9.3 (for PET) and 45 h (for PLA). A longer excretion period of PLA may be related to its potential to break down in the earthworms' digestive tract. This not only promotes the environmental degradation of PLA but also suggests the ecological risk caused by nanoparticles.

A novel chitosan-urea encapsulated material for persulfate slow-release to degrade organic pollutants

A novel eco-friendly material (CS-U@PS) for persulfate slow-release to effectively degrade organic pollutants (methyl orange and pyrene) was synthesized using chitosan and urea as the encapsulated framework materials via an emulsion cross-linking method for the first time. The obtained CS-U@PS exhibits spherical shapes with a uniform size of approximately 2-3 µm according to the particle-size distribution and SEM image results. The slow-release mechanism was proposed through a kinetics model study and the Ritger-Peppas model fit well (r² = 0.9699) to indicate that the slow-release process is non-Fickian diffusion. The influences of urea and PS dosages and oxidative conditions on methyl orange degradation were studied, and all the results suggested that urea played an important role in PS slow-release and can also catalyze the activation of PS by iron to further produce radicals and improve the removal efficiency of pollutants. A pyrene removal rate of 90.53% was achieved in aqueous solutions and an above 80% removal rate was obtained in weakly acidic or neutral soil environments by CS-U@PS activated by Fe²⁺ with citric acid as the chelating agent. Therefore, the fabricated slow-release oxidation materials exhibit application potential for the remediation of organic polluted groundwater and soil.

Economic burden of public health care and hospitalisation associated with COVID-19 in China

OBJECTIVES

This study aimed to evaluate the socio-economic burden imposed on the Chinese healthcare system during the coronavirus disease 2019 (COVID-19) pandemic.

STUDY DESIGN

A cross-sectional study was used to investigate how COVID-19 impacted health and medical costs in China. Data were derived from a subdivision of the Centers for Disease control and Prevention of China.

METHODS

We prospectively collected information from the Centers for Disease Control and Prevention and the designated hospitals to determine the cost of public health care and hospitalisation due to COVID-19. We estimated the resource use and direct medical costs associated with public health.

RESULTS

The average costs, per case, for specimen collection and nucleic acid testing (NAT [specifically, polymerase chain reaction {PCR}]) in low-risk populations were $29.49 and $53.44, respectively; however, the average cost of NAT in high-risk populations was $297.94 per capita. The average costs per 1000 population for epidemiological surveys, disinfectant, health education and centralised isolation were $49.54, $247.01, $90.22 and $543.72, respectively. A single hospitalisation for COVID-19 in China cost a median of $2158.06 ($1961.13-$2325.65) in direct medical costs incurred only during hospitalisation, whereas the total costs associated with hospitalisation of patients with COVID-19 were estimated to have reached nearly $373.20 million in China as of 20, May, 2020. The cost of public health care associated with COVID-19 as of 20, May, 2020 ($6.83 billion) was 18.31 times that of hospitalisation.

CONCLUSIONS

This study highlights the magnitude of resources needed to treat patients with COVID-19 and control the COVID-19 pandemic. Public health measures implemented by the Chinese government have been valuable in reducing the infection rate and may be cost-effective ways to control emerging infectious diseases.