International Variation in Severe Exacerbation Rates in Patients With Severe Asthma

BACKGROUND

Exacerbation frequency strongly influences treatment choices in patients with severe asthma.

RESEARCH QUESTION

What is the extent of the variability of exacerbations rate across countries and its implications in disease management?

STUDY DESIGN AND METHODS

We retrieved data from the International Severe Asthma Registry, an international observational cohort of patients with a clinical diagnosis of severe asthma. We identified patients ≥ 18 years of age who did not initiate any biologics prior to baseline visit. A severe exacerbation was defined as the use of oral corticosteroids for ≥ 3 days or asthma-related hospitalization/ED visit. A series of negative binomial models were applied to estimate country-specific severe exacerbation rates during 365 days of follow-up, starting from a naïve model with country as the only variable to an adjusted model with country as a random-effect term and patient and disease characteristics as independent variables.

RESULTS

The final sample included 7,510 patients from 17 countries (56% from the United States), contributing to 1,939 severe exacerbations (0.27/person-year). There was large between-country variation in observed severe exacerbation rate (minimum, 0.04 [Argentina]; maximum, 0.88 [Saudi Arabia]; interquartile range, 0.13-0.54), which remained substantial after adjusting for patient characteristics and sampling variability (interquartile range, 0.16-0.39).

INTERPRETATION

Individuals with similar patient characteristics but coming from different jurisdictions have varied severe exacerbation risks, even after controlling for patient and disease characteristics. This suggests unknown patient factors or system-level variations at play. Disease management guidelines should recognize such between-country variability. Risk prediction models that are calibrated for each jurisdiction will be needed to optimize treatment strategies.

Cost-effectiveness of budesonide-formoterol vs inhaled epinephrine in US adults with mild asthma

BACKGROUND

The management of mild asthma has lacked an over-the-counter (OTC) option aside from inhaled epinephrine, which is available in the United States. However, inhaled epinephrine use without an inhaled corticosteroid may increase the risk of asthma death.

OBJECTIVE

To compare the cost-effectiveness of OTC as-needed budesonide-formoterol as a plausible alternative to inhaled epinephrine.

METHODS

We developed a probabilistic Markov model to compare OTC as-needed budesonide-formoterol inhaler use vs inhaled epinephrine use in adults with mild asthma from a US societal perspective over a lifetime horizon, with a 3% annual discount rate (2022 US dollars). Inputs were derived from the SYmbicort Given as-needed in Mild Asthma (SYGMA) trials, published literature, and commercial costs. Outcomes were quality-adjusted life-years (QALY), costs, incremental net monetary benefit (INMB), severe asthma exacerbations, well-controlled asthma days, and asthma-related deaths. Microsimulation was used to evaluate underinsured Americans living with mild asthma (n = 5,250,000).

RESULTS

Inhaled epinephrine was dominated (with lower QALYs gains at a higher cost) by both as-needed budesonide-formoterol (INMB, $15,541 at a willingness-to-pay of $100,000 per QALY) and the no-OTC inhaler option (INMB, $1023). Adults using as-needed budesonide-formoterol had 145 more well-controlled asthma days, 2.79 fewer severe exacerbations, and an absolute risk reduction of 0.23% for asthma-related death compared with inhaled epinephrine over a patient lifetime. As-needed budesonide-formoterol remained dominant in all sensitivity and scenario analyses, with a 100% probability of being cost-effective compared with inhaled epinephrine in probabilistic sensitivity analysis.

CONCLUSION

If made available, OTC as-needed budesonide-formoterol for treating mild asthma in underinsured adults without HCP management improves asthma outcomes, prevents fatalities, and is cost-saving.

High-performance monolayer MoS2nanosheet GAA transistor

In this article, a 0.7 nm thick monolayer MoS2nanosheet gate-all-around field effect transistors (NS-GAAFETs) with conformal high-κmetal gate deposition are demonstrated. The device with 40 nm channel length exhibits a high on-state current density of ~410μAμm-1with a large on/off ratio of 6 × 108at drain voltage = 1 V. The extracted contact resistance is 0.48 ± 0.1 kΩμm in monolayer MoS2NS-GAAFETs, thereby showing the channel-dominated performance with the channel length scaling from 80 to 40 nm. The successful demonstration of device performance in this work verifies the integration potential of transition metal dichalcogenides for future logic transistor applications.

QRISK3 underestimates the risk of cardiovascular events in patients with COPD

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of cardiovascular disease (CVD). The extent to which the excess CVD risk is captured by risk factors in QRISK, a widely used CVD risk scoring tool, is not well studied.

METHODS

We created an incidence cohort of diagnosed COPD patients from the United Kingdom (UK) Clinical Practice Research Datalink GOLD database (January 1998-July 2018). The outcome was a composite of fatal or non-fatal CVD events. Sex-specific age-standardised incidence ratios (SIR) were compared with values for the UK primary-care population. The observed 10-year CVD risk was derived using the Kaplan-Meier estimator and was compared with predicted 10-year risk from the QRISK3 tool.

RESULTS

13 208 patients (mean age 64.9 years, 45% women) were included. CVD incidence was 3.53 events per 100 person-years. The SIR of CVD was 1.71 (95% CI 1.61 to 1.75) in women and 1.62 (95%CI 1.54-1.64) in men. SIR was particularly high among patients younger than 65 years (women=2.13 (95% CI 1.94 to 2.19); men=1.86 (95% CI 1.74 to 1.90)). On average, the observed 10-year risk was 52% higher than QRISK predicted score (33.5% vs 22.1%). The difference was higher in patients younger than 65 years (observed risk 82% higher than predicted).

CONCLUSION

People living with COPD are at a significantly heightened risk of CVD over and beyond their predicted risk. This is particularly the case for younger people whose 10-year CVD risk can be >80% higher than predicted. Risk scoring tools must be validated and revised to provide accurate CVD predictions in patients with COPD.

Trends in hospital admissions for chronic obstructive pulmonary disease over 16 years in Canada

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an ambulatory care-sensitive condition, and the rate of hospital admissions for COPD is an indicator of the quality of outpatient care. We sought to determine long-term trends in hospital admissions for COPD in Canada.

METHODS

Using a comprehensive national database of hospital admissions in Canada, we identified those with a main discharge diagnosis of COPD for patients aged 40 years and older between 2002 and 2017. We calculated sex-specific, age-standardized trends in annual rates of hospital admissions for COPD separately for younger (40-64 yr) and older adults (≥ 65 yr). We used spline regression to examine changes in the admissions trends for each sex and age group.

RESULTS

Over 16 years, 1 134 359 hospital admissions were for COPD. Between 2002 and 2017, the total number of admissions increased by 68.8%, from 52 937 to 89 384. The overall crude admission rate increased by 30.0%, from 368 to 479 per 100 000 population, and the sex-and age-standardized admission rate increased by 9.6%, from 437 to 479 per 100 000 population. Age-standardized rates increased by 12.2% among younger females, by 24.4% among younger males and by 29.8% among older females, but decreased by 9.0% among older males. Over the same period, the all-cause sex-and age-standardized admission rate declined by 23.0%.

INTERPRETATION

Hospital admissions for COPD have increased since 2010, even after adjusting for population growth and aging, and despite declining rates of all-cause hospital admissions. The secular increase in COPD admissions indicates that the burden of COPD on Canadian health care systems is increasing.

Value-of-Information Analysis for External Validation of Risk Prediction Models

BACKGROUND

A previously developed risk prediction model needs to be validated before being used in a new population. The finite size of the validation sample entails that there is uncertainty around model performance. We apply value-of-information (VoI) methodology to quantify the consequence of uncertainty in terms of net benefit (NB).

METHODS

We define the expected value of perfect information (EVPI) for model validation as the expected loss in NB due to not confidently knowing which of the alternative decisions confers the highest NB. We propose bootstrap-based and asymptotic methods for EVPI computations and conduct simulation studies to compare their performance. In a case study, we use the non-US subsets of a clinical trial as the development sample for predicting mortality after myocardial infarction and calculate the validation EVPI for the US subsample.

RESULTS

The computation methods generated similar EVPI values in simulation studies. EVPI generally declined with larger samples. In the case study, at the prespecified threshold of 0.02, the best decision with current information would be to use the model, with an incremental NB of 0.0020 over treating all. At this threshold, the EVPI was 0.0005 (relative EVPI = 25%). When scaled to the annual number of heart attacks in the US, the expected NB loss due to uncertainty was equal to 400 true positives or 19,600 false positives, indicating the value of further model validation.

CONCLUSION

VoI methods can be applied to the NB calculated during external validation of clinical prediction models. While uncertainty does not directly affect the clinical implications of NB findings, validation EVPI provides an objective perspective to the need for further validation and can be reported alongside NB in external validation studies.

HIGHLIGHTS

External validation is a critical step when transporting a risk prediction model to a new setting, but the finite size of the validation sample creates uncertainty about the performance of the model.In decision theory, such uncertainty is associated with loss of net benefit because it can prevent one from identifying whether the use of the model is beneficial over alternative strategies.We define the expected value of perfect information for external validation as the expected loss in net benefit by not confidently knowing if the use of the model is net beneficial.The adoption of a model for a new population should be based on its expected net benefit; independently, value-of-information methods can be used to decide whether further validation studies are warranted.

Engineered tenorite structure of barium-enriched copper oxide for on-site monitoring of cytotoxic methotrexate in environmental samples

Emerging pharmaceutical pollutants pose a threat to both human and environmental health. The removal and monitoring of such pollutants necessitate the use of practical on-site monitoring devices; however, the designs of such devices are underdeveloped. This study involves the fabrication of a low-cost sensor based on barium-incorporated copper oxide (Ba-CuO) for the on-site monitoring of the cytotoxic drug methotrexate (MTRX) in water and sediment samples. The tenorite structure of CuO was slightly enriched with Ba ions at the td sites, distorting the tetrahedron and enhancing its electrochemical properties. Ba-CuO was obtained from Cu(NO₃)₂ and Ba(OH)₂ by a ligand exchange protocol and was characterized using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analysis. In addition, the Ba-CuO sensor was tested under various conditions, and it could detect MTRX at concentrations as low as 0.4 nM, with a high sensitivity of 1.3567 µA µM^-1 cm^-2. On-site monitoring yielded recoveries of greater than 93 % from spiked samples, thus exhibiting excellent reproducibility and stability. Therefore, the developed method is practical and has no matrix effect on the MTRX sensor.

Closed-Form Solution of the Unit Normal Loss Integral in 2 Dimensions, with Application in Value-of-Information Analysis

HIGHLIGHTS

The unit normal loss integral (UNLI) is widely used in decision analysis and risk modeling, including in the computation of various value-of-information metrics, but its closed-form solution is only applicable to comparisons of 2 strategies.We derive a closed-form solution for 2-dimensional UNLI, extending the applicability of the UNLI to 3-strategy comparisons.Such closed-form computation takes only a fraction of a second and is free from simulation errors that affect the hitherto available methods.In addition to the relevance in 3-strategy model-based and data-driven decision analyses, a particular application is in risk prediction modeling, where the net benefit of a classifier should always be compared with 2 default strategies of treating none and treating all.

Individualised risk prediction model for exacerbations in patients with severe asthma: protocol for a multicentre real-world risk modelling study

INTRODUCTION

Severe asthma is associated with a disproportionally high disease burden, including the risk of severe exacerbations. Accurate prediction of the risk of severe exacerbations may enable clinicians to tailor treatment plans to an individual patient. This study aims to develop and validate a novel risk prediction model for severe exacerbations in patients with severe asthma, and to examine the potential clinical utility of this tool.

METHODS AND ANALYSIS

The target population is patients aged 18 years or older with severe asthma. Based on the data from the International Severe Asthma Registry (n=8925), a prediction model will be developed using a penalised, zero-inflated count model that predicts the rate or risk of exacerbation in the next 12 months. The risk prediction tool will be externally validated among patients with physician-assessed severe asthma in an international observational cohort, the NOVEL observational longiTudinal studY (n=1652). Validation will include examining model calibration (ie, the agreement between observed and predicted rates), model discrimination (ie, the extent to which the model can distinguish between high-risk and low-risk individuals) and the clinical utility at a range of risk thresholds.

ETHICS AND DISSEMINATION

This study has obtained ethics approval from the Institutional Review Board of National University of Singapore (NUS-IRB-2021-877), the Anonymised Data Ethics and Protocol Transparency Committee (ADEPT1924) and the University of British Columbia (H22-01737). Results will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

European Union electronic Register of Post-Authorisation Studies, EU PAS Register (EUPAS46088).

Effect of Rowachol on the Gallbladder Dysmotility Disorder Based on Gallbladder Ejection Fraction

Background and Objectives: Although laparoscopic cholecystectomy is the preferred treatment method in patients who experience typical biliary pain with or without gallstones, medical treatment has not been extensively studied. Rowachol is a potent choleretic agent, comprising six cyclic monoterpenes. This study aimed to investigate the clinical improvement and changes in gallbladder ejection fraction (GBEF) by Rowachol treatment in patients with typical biliary pain. Materials and Methods: We retrospectively reviewed 138 patients with typical biliary pain who underwent cholescintigraphy from July 2016 to April 2022. We included patients who received Rowachol for more than 2 months and underwent follow-up GBEF measurements. Finally, we analyzed pre- and post-treatment symptoms and GBEF. GBEF was calculated using the fatty meal-stimulated cholescintigraphy. Results: This retrospective observational study included 31 patients; their median age was 46.0 (range, 26.0-72.7) years, and 22 (71.0%) were female. Overall, 9 (29.0%) patients had gallbladder stones or sludges (maximum size: 2 mm) on initial transabdominal ultrasonography. During a median follow-up of 23.3 months, the symptoms of 21 (67.7%) patients were resolved after a median Rowachol treatment of 10.0 months. The mean GBEF was significantly improved after Rowachol treatment (initial cholescintigraphy: 42.6% ± 16.2%; follow-up cholescintigraphy: 53.0% ± 18.1%, p = 0.012). In patients with a GBEF ≤35% (n = 9), Rowachol significantly increased the GBEF from 21.3% ± 8.3% to 49.1% ± 20.7% (p = 0.008). Conclusions: Rowachol may have beneficial medical effects that can improve gallbladder dysfunction and treatment response.

Effect of age on the prognosis of intrahepatic cholangiocarcinoma

BACKGROUND/AIMS

Intrahepatic cholangiocarcinoma (iCCA) is a subgroup of cholangiocarcinoma and is the second- most-common primary hepatic tumor. Several predictive and prognostic factors have been analyzed; however, in this study we focused on the influence of age. Our aim was to use real-world results to determine the influence of age in iCCA patients.

METHODS

A retrospective analysis of patients treated between 2005 and 2016 at Konkuk University Medical Center. In total, 133 patients with iCCA were identified. The mass-forming, periductal-infiltrating, and intraductal-growth types were included; patients with extrahepatic or hilar-type cholangiocarcinoma were excluded. We defined two groups: a younger group, age < 65 years, and an older group, age ≥ 65 years. Statistical analyses using univariate and multivariate Cox regression analyses, including the Kaplan-Meier method, were conducted.

RESULTS

In total, 114 patients were enrolled. The two groups differed with regard to treatment options such as surgery with adjuvant chemotherapy or palliative chemotherapy (p = 0.012, p < 0.001). The younger group had significantly longer survival than the older group (p = 0.017). In the younger group, patients who received therapy had longer survival than those who did not (hazard ratio, 3.942; 95% confidence interval, 2.053 to 7.569; p < 0.001). Multivariate analysis indicated that younger age, lower bilirubin, low CA 19-9, and no lymph-node involvement were independent factors for improved survival.

CONCLUSION

Younger patients and those who underwent surgery with adjuvant chemotherapy had longer survival. The younger the patient, the more treatments received, including palliative chemotherapy.

Arterial reinforcement following pancreatoduodenectomy: The solution to prevent delayed hemorrhage caused by postoperative pancreatic fistula

PURPOSE

Delayed hemorrhage (DH) is a rare and yet well-known fatal complication associated with postoperative pancreatic fistula (POPF) in pancreatoduodenectomy (PD). The study aimed to investigate whether arterial reinforcement (AR) using polyglycolic acid sheets (PAS) followed by fibrin sealant (FS) to the hepatic artery could prevent DH in the setting of POPF after PD.

METHODS

A total of 345 patients underwent PD for periampullary tumors from March 2011 to March 2022. From March 2011 to March 2018, 225 patients underwent PD, and AR was not performed (non-AR group). From April 2018 to March 2022, 120 patients underwent PD, and AR was performed (AR group). AR was achieved by wrapping the proper hepatic artery all the way down to the celiac artery with PAS followed by coating with FS. Demographic profile and various outcomes including DH of these two groups were compared and analyzed retrospectively.

RESULTS

In non-AR group, 48 (21.3%) and 12 (5.3%) patients had grade B and C POPF, respectively. In AR group, 26 (21.7%) and four (3.3%) patients had grade B and C POPF, respectively. The incidence of POPF was not statistically significant (p = .702) between the groups. Among the patients with grade B or C POPF, DH occurred in 14 (23.3%) patients in non-AR group and only one patient in AR group (p = .016). Of the 15 patients with DH, four (26.7%) patients died.

CONCLUSION

AR using PAS and FS is effective in preventing DH in the setting of POPF.

Lanthanum tin oxide-modified sensor electrode for the rapid detection of environmentally hazardous insecticide carbaryl in soil, water, and vegetable samples

The growing population and global food demands have encouraged the use of pesticides to increase agricultural yields; however, the irrational use of pesticides threatens human health and the environment. Carbaryl (CRBL) is the most widespread insecticide and severely affects soil, water systems, and human health. Thus, it is crucial to monitor CRBL residues in the environment and vegetable samples. This study reports the rapid and sensitive electrochemical detection of CRBL based on a pyrochlore-type lanthanum tin oxide (LSO) nanoparticles (NPs)-modified screen-printed carbon electrode (SPCE). A low-temperature hydrothermal method was employed to prepare the LSO NPs. The structural properties of the LSO NPs were characterized by X-ray diffraction, Raman, and X-ray photoelectron spectroscopy analyses. The LSO NPs/SPCE demonstrated good electroanalytical performance for CRBL detection, with a low detection limit of 0.4 nM (0.08 µg/L) and a sensitivity of 1.05 µA/(µM cm²). Furthermore, the LSO NPs/SPCE exhibited high selectivity among highly interfering carbamate and organophosphorus pesticides, which share similar mechanisms of action. Additionally, the LSO NPs/SPCE sensor achieved > 90% recovery for the detection of CRBL in soil, water, and vegetable samples, thus verifying its suitability for the rapid detection of CRBL.

Safety of performing distal pancreatosplenectomy in patients who underwent distal gastrectomy previously: a multicenter cohort analysis with systematic literature review

Purpose

In patients who have previously undergone subtotal gastrectomy (STG), the remnant stomach is supplied with arterial blood through the splenic artery. It is currently unclear whether the remnant stomach can be safely preserved when performing distal pancreatosplenectomy (DPS) in these patients. Thus, this study aimed to evaluate the safety and feasibility of performing DPS in patients who had undergone a previous STG.

Methods

A multicenter cohort study was performed to identify patients who underwent DPS. Electronic medical data of Clinical Data Warehouse from 7 representative high-volume centers in 5 cities were retrospectively reviewed. A propensity score-matched analysis was performed to match patients who had no history of upper abdominal surgery with patients who had undergone a previous STG.

Results

Fourteen DPS patients who had a history of STG (STG group) were studied and matched to 70 patients who underwent DPS without any history of upper abdominal surgery (non-STG group). All patients in the STG group had the remnant stomach preserved. In most patients, the blood vessel supplying blood to the remnant stomach was the left inferior phrenic artery. There was no significant difference in the incidence of stomach-related complications or length of hospital stay between the 2 groups.

Conclusion

Our study results suggest that the remnant stomach could be safely preserved when performing DPS in patients with a prior STG. However, it is necessary to carefully evaluate the vascular structure of the remnant stomach through preoperative imaging study and closely observe changes to the blue stomach during the operation.

ACCEPT 2·0: Recalibrating and externally validating the Acute COPD exacerbation prediction tool (ACCEPT)

BACKGROUND

The Acute Chronic Obstructive Pulmonary Disease (COPD) Exacerbation Prediction Tool (ACCEPT) was developed for individualised prediction of COPD exacerbations. ACCEPT was well calibrated overall and had a high discriminatory power, but overestimated risk among individuals without recent exacerbations. The objectives of this study were to 1) fine-tune ACCEPT to make better predictions for individuals with a negative exacerbation history, 2) develop more parsimonious models, and 3) externally validate the models in a new dataset.

METHODS

We recalibrated ACCEPT using data from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE, a three-year observational study, 1,803 patients, 2,117 exacerbations) study by applying non-parametric regression splines to the predicted rates. We developed three reduced versions of ACCEPT by removing symptom score and/or baseline medications as predictors. We examined the discrimination, calibration, and net benefit of ACCEPT 2·0 in the placebo arm of the Towards a Revolution in COPD Health (TORCH, a three-year randomised clinical trial of inhaled therapies in COPD, 1,091 patients, 1,064 exacerbations) study. The primary outcome for prediction was the occurrence of ≥2 moderate or ≥1 severe exacerbation in the next 12 months; the secondary outcomes were prediction of the occurrence of any moderate/severe exacerbation or any severe exacerbation.

FINDINGS

ACCEPT 2·0 had an area-under-the-curve (AUC) of 0·76 for predicting the primary outcome. Exacerbation history alone (current standard of care) had an AUC of 0·68. The model was well calibrated in patients with positive or negative exacerbation histories. Changes in AUC in reduced versions were minimal for the primary outcome as well as for predicting the occurrence of any moderate/severe exacerbations (ΔAUC<0·011), but more substantial for predicting the occurrence of any severe exacerbations (ΔAUC<0·020). All versions of ACCEPT 2·0 provided positive net benefit over the use of exacerbation history alone for some range of thresholds.

INTERPRETATION

ACCEPT 2·0 showed good calibration regardless of exacerbation history, and predicts exacerbation risk better than current standard of care for a range of thresholds. Future studies need to investigate the utility of exacerbation prediction in various subgroups of patients.

FUNDING

This study was funded by a team grant from the Canadian Institutes of Health Research (PHT 178432).

Effect of the Ni3TeO6 phase in a Ni2Te3O8/expanded graphite composite on the electrochemical monitoring of metribuzin residue in soil and water samples

Growing food demand and climate change have led to the development of various pest control agents to increase crop yields. Although pesticides help meet the food demand, they cause harm to human health and the environment. Metribuzin (MTBZ) is one of the common herbicides used for controlling weeds. Therefore, monitoring MTBZ residues in soil and water bodies is essential for decreasing risk to the environment and human health. This paper reports a highly selective and sensitive electrochemical sensor electrode based on a Ni₃TeO₆-phase-integrated Ni₂Te₃O₈/expanded graphite (referred to here as NTO-eGR) composite for the detection of MTBZ. The NTO-eGR composite was prepared by a one-step low-temperature hydrothermal method and characterized by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and electron microscopy techniques. The Ni₃TeO₆ phase was found to be an active component in the NTO/eGR composite, which exhibited satisfactory analytical performance in MTBZ detection with a sensitivity of 1.454 µA µM^-1 cm^-2. Moreover, the NTO-eGR electrode exhibited high selectivity to MTBZ even in the presence of a five-fold excess of interfering species in water and soil samples. The studies on practical applicability revealed that NTO-eGR exhibits good reproducibility with a relative standard deviation of 2.67% (n = 5). Moreover, good recoveries of greater than 90% were achieved in the determination of MTBZ in soil and water samples. Hence, the NTO-eGR sensor electrode is highly suitable for the rapid on-site determination of MTBZ.

Uncertainty and the Value of Information in Risk Prediction Modeling

Background

Because of the finite size of the development sample, predicted probabilities from a risk prediction model are inevitably uncertain. We apply value-of-information methodology to evaluate the decision-theoretic implications of prediction uncertainty.

Methods

Adopting a Bayesian perspective, we extend the definition of the expected value of perfect information (EVPI) from decision analysis to net benefit calculations in risk prediction. In the context of model development, EVPI is the expected gain in net benefit by using the correct predictions as opposed to predictions from a proposed model. We suggest bootstrap methods for sampling from the posterior distribution of predictions for EVPI calculation using Monte Carlo simulations. We used subsets of data of various sizes from a clinical trial for predicting mortality after myocardial infarction to show how EVPI changes with sample size.

Results

With a sample size of 1000 and at the prespecified threshold of 2% on predicted risks, the gains in net benefit using the proposed and the correct models were 0.0006 and 0.0011, respectively, resulting in an EVPI of 0.0005 and a relative EVPI of 87%. EVPI was zero only at unrealistically high thresholds (>85%). As expected, EVPI declined with larger samples. We summarize an algorithm for incorporating EVPI calculations into the commonly used bootstrap method for optimism correction.

Conclusion

The development EVPI can be used to decide whether a model can advance to validation, whether it should be abandoned, or whether a larger development sample is needed. Value-of-information methods can be applied to explore decision-theoretic consequences of uncertainty in risk prediction and can complement inferential methods in predictive analytics. R code for implementing this method is provided.

Development of a conceptual model of childhood asthma to inform asthma prevention policies

Background

There is no definitive cure for asthma, as prevention remains a major goal. Decision analytic models are routinely used to evaluate the value-for-money proposition of interventions. Following best practice standards in decision-analytic modelling, the objective of this study was to solicit expert opinion to develop a concept map for a policy model for primary prevention of asthma.

Methods

We reviewed currently available decision analytic models for asthma prevention. A steering committee of economic modellers, allergists and respirologists was then convened to draft a conceptual model of paediatric asthma. A modified Delphi method was followed to define the context of the problem at hand (evaluation of asthma prevention strategies) and develop the concept map of the model.

Results

Consensus was achieved after three rounds of discussions, followed by concealed voting. In the final conceptual model, asthma diagnosis was based on three domains of lung function, atopy and their symptoms. The panel recommended several markers for each domain. These domains were in turn affected by several risk factors. The panel clustered all risk factors under three groups of ‘patient characteristic’, ‘family history’ and ‘environmental factors’. To be capable of modelling the interplay among risk factors, the panel recommended the use of microsimulation, with an open-population approach that would enable modelling phased implementation and gradual and incomplete uptake of the intervention.

Conclusions

Economic evaluation of childhood interventions for preventing asthma will require modelling of several codependent risk factors and multiple domains that affect the diagnosis. The conceptual model can inform the development and validation of a policy model for childhood asthma prevention.

Longstanding postoperative fluid collection influences recurrence of pancreatic malignancy

BACKGROUND/AIMS

Postoperative abdominal fluid collection (PAFC) is a frequent complication of pancreatobiliary cancer surgery. The effects of the existence and duration of PAFC are not well known. This study aimed to assess the effects of PAFC on patient prognosis after surgery for pancreatobiliary adenocarcinoma and the association of longstanding PAFC with the recurrence of pancreatic cancer.

METHODS

We retrospectively analyzed the data of 194 consecutive patients with pancreatobiliary adenocarcinoma who underwent curative operations from August 2005 to December 2019. The presence of PAFC was assessed using computed tomography within a week of surgery; PAFC lasting > 4 weeks was defined as longstanding PAFC.

RESULTS

Among 194 patients, PAFC occurred in 165 (85.1%), and 74 of these had longstanding PAFC. The recurrence rate of pancreatobiliary adenocarcinoma was significantly higher in patients with longstanding PAFC than in patients with non-longstanding PAFC (p = 0.025). Recurrence was also significantly associated with high T stage (T3, T4; p = 0.040), lymph node involvement (p < 0.001), perineural invasion (p < 0.006), and non-receipt of adjuvant chemotherapy (p = 0.025). Longstanding PAFC was significantly associated with the recurrence of pancreatic adenocarcinoma (p = 0.016). However, cancer-specific survival was related to neither the presence nor the duration of PAFC.

CONCLUSION

The presence of longstanding PAFC was associated with the recurrence of pancreatic adenocarcinoma. However, a larger prospective study is necessary to confirm the findings.

Tryptamine-functionalized magnetic nanoparticles for highly sensitive detection of Salmonella typhimurium

There is significant demand for the development of rapid, sensitive, and specific methods for detecting bacterial pathogens in order to identify the causes of food poisoning. Nucleic acid amplification tests (NAATs) allow for the culture-free detection of bacterial pathogens and are not as labor intensive and time consuming as culture-based detection methods. However, suitable sample preparation methods must be developed for the realization of simple, rapid, and sensitive NAATs. To resolve this problem, we developed a new sample preparation method that integrates bacterial pathogen enrichment and DNA extraction. We engineered magnetic nanoparticles (MNPs) with a physicochemical probe (tryptamine) for single-tube sample preparation with minimal sample loss. The tryptamine-functionalized MNPs (Indole@MNPs) showed inherent hydrophobicity owing to the indole side chain and a change in their zeta potential with a decrease in the pH. Because of their physicochemical characteristics, the Indole@MNPs could adsorb bacterial pathogens, thus allowing sample enrichment and DNA binding and release through weak electrostatic interactions via pH control. We successfully detected Salmonella enterica serovar Typhimurium, a common cause of bacterial food poisoning, at a concentration of 10 CFU/10 mL in milk samples using quantitative PCR. Thus, the proposed method allows for the simple and sensitive detection of Salmonella typhimurium and can be used for nontyphoidal salmonella detection to ensure food safety.

Carbon Dot/Naphthalimide Based Ratiometric Fluorescence Biosensor for Hyaluronidase Detection

Bladder cancer is the leading cause of death in patients with genitourinary cancer. An elevated level of hyaluronidase (HAase) was found in bladder cancer, which acts as an important biomarker for the early diagnosis of bladder cancer. Hence, there is a need to develop a simple enzymatic assay for the early recognition of HAase. Herein, we report a simple, sensitive, and ratiometric fluorescence assay for HAase detection under physiological conditions. The fluorescence assay was constructed by the adsorption of cationic carbon dots and positively charged naphthalimide on negatively charged hyaluronic acid and the development of a Förster resonance energy transfer (FRET) mechanism from carbon dots to a naphthalimide fluorophores. The hyaluronidase enzyme cleaves the hyaluronic acid in this assay, and breaking down the FRET mechanism induces ratiometric changes. A detection limit of 0.09 U/mL was achieved, which is less than the HAase level found in normal human body fluids. Moreover, this assay may be used for diagnosing HAase-related diseases.

Should the number of acute exacerbations in the previous year be used to guide treatments in COPD?

BACKGROUND

In contemporary management of chronic obstructive pulmonary disease (COPD), the frequent exacerbator phenotype, based on a 12-month history of acute exacerbation of COPD (AECOPD), is a major determinant of therapeutic recommendations. However, there is considerable debate as to the stability of this phenotype over time.

METHODS

We used fundamental principles in time-to-event analysis to demonstrate that variation in the frequent exacerbator phenotype has two major sources: variability in the underlying AECOPD rate and randomness in the occurrence of individual AECOPDs. We re-analysed data from two large cohorts, the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study and the SubPopulations and InteRmediate OutcoMes In COPD Study (SPIROMICS), using a Bayesian model that separated these sources of variability. We then evaluated the stability of the frequent exacerbator phenotype based on these results.

RESULTS

In both cohorts, the pattern of AECOPDs strongly supported the presence of an individual-specific underlying AECOPD rate which is stable over time (Bayes Factor less than 0.001). Despite this, the observed AECOPD rate can vary markedly year-to-year within individual patients. For those with an underlying rate of 0.8-3.1 events·year-1, the frequent exacerbator classification, based on the observed rate, changes more than 30% of the time over two consecutive years due to chance alone. This value increases to more than 45% for those with an underlying rate of 1.2-2.2 events·year-1.

CONCLUSIONS

While the underlying AECOPD rate is a stable trait, the frequent exacerbator phenotype based on observed AECOPD patterns is unstable, so much so that its suitability for informing treatment decisions should be questioned. Whether evaluating AECOPD history over longer durations or using multivariate prediction models can result in more stable phenotyping needs to be evaluated.

A cluster-based analysis evaluating the impact of comorbidities in fibrotic interstitial lung disease

Background

Comorbidities are frequent and have been associated with poor quality of life, increased hospitalizations, and mortality in patients with interstitial lung disease (ILD). However, it is unclear how comorbidities lead to these negative outcomes and whether they could influence ILD disease progression. The goal of this study was to identify clusters of patients based on similar comorbidity profiles and to determine whether these clusters were associated with rate of lung function decline and/or mortality.

Methods

Patients with a major fibrotic ILD (idiopathic pulmonary fibrosis (IPF), fibrotic hypersensitivity pneumonitis, connective tissue disease-associated ILD, and unclassifiable ILD) from the CAnadian REgistry for Pulmonary Fibrosis (CARE-PF) were included. Hierarchical agglomerative clustering of comorbidities, age, sex, and smoking pack-years was conducted for each ILD subtype to identify combinations of these features that frequently occurred together in patients. The association between clusters and change in lung function over time was determined using linear mixed effects modeling, with adjustment for age, sex, and smoking pack-years. Kaplan Meier curves were used to assess differences in survival between the clusters.

Results

Discrete clusters were identified within each fibrotic ILD. In IPF, males with obstructive sleep apnea (OSA) had more rapid decline in FVC %-predicted (− 11.9% per year [95% CI − 15.3, − 8.5]) compared to females without any comorbidities (− 8.1% per year [95% CI − 13.6, − 2.7]; p = 0.03). Females without comorbidities also had significantly longer survival compared to all other IPF clusters. There were no significant differences in rate of lung function decline or survival between clusters in the other fibrotic ILD subtypes.

Conclusions

The combination of male sex and OSA may portend worse outcomes in IPF. Further research is required to elucidate the interplay between sex and comorbidities in ILD, as well as the role of OSA in ILD disease progression.

Robotic surgery enables safe and comfortable single-incision cholecystectomy: A comparison of robotic and laparoscopic approaches for single-incision surgery

Background:

Although single-incision robotic cholecystectomy (SIRC) overcomes various limitations of single-incision laparoscopic cholecystectomy (SILC), it is associated with high cost. In this study, we intended to investigate if SIRC is recommendable and advantageous to patients despite its high cost.

Materials and Methods:

We prospectively collected and analysed data of patients who had undergone either SILC (n = 25) or SIRC (n = 50) for benign gallbladder diseases, with identical inclusion criteria, between November 2017 and February 2019.

Results:

SILC and SIRC showed similar operative outcomes in terms of intra- and post-operative complications and verbal numerical rating scale (VNRS) for pain. However, the SIRC group exhibited significantly longer operation time than the SILC group (83.2 ± 32.6 vs. 66.4 ± 32.8, P = 0.002). The SIRC group also showed longer hospital stay (2.4 ± 0.7 vs. 2.2 ± 0.6, P = 0.053). Although the SILC and SIRC groups showed no significant difference in VNRS, the SIRC group required a higher amount (126.0 ± 88.8 mg vs. 87.5 ± 79.7 mg, P = 0.063) and frequency (3.0 ± 2.1 vs. 2.0 ± 1.8, P = 0.033) of intravenous opioid analgesic administration. During surgery, the critical view of safety (CVS), the prerequisite for safe cholecystectomy, was identified in only 24% (n = 6) of patients undergoing SILC and in 100% (n = 50) of patients undergoing SIRC (P < 0.05).

Conclusion:

We conclude that although SILC and SIRC have similar operative outcomes, SIRC is advantageous over SILC because of its potential to markedly enhance the safety of patients by proficiently acquiring CVS.

Prognostic impact of hepatitis B or C on intrahepatic cholangiocarcinoma

BACKGROUND/AIMS

Intrahepatic cholangiocarcinoma (ICC) is the second-most common primary liver malignancy, arising from the peripheral intrahepatic bile duct epithelium. Hepatitis B virus (HBV) or hepatitis C virus (HCV) may be involved in the development of ICC. We explored the prognostic value of hepatitis virus infection, as well as other prognostic factors affecting survival in patients with ICC.

METHODS

A retrospective chart review was performed for patients diagnosed with ICC between August 2005 and December 2018 at Konkuk University Medical Center. We identified a total of 131 patients with ICC. Overall survival rates of patients with and without hepatitis were determined. Univariate and multivariate analyses were used to estimate factors influencing survival outcomes.

RESULTS

A total of 17.6% (23/131) of patients were positive for HBV or HCV. Hepatitis B positive ICC patients were significantly younger with higher albumin and higher α-fetoprotein than those without hepatitis viral infections. The median survival of hepatitis-positive and hepatitis-negative groups was 280 and 213 days, respectively. Survival rates were not significantly different between the two groups (p = 0.279). Multivariate analyses indicated that lower serum carbohydrate antigen 19-9 (CA 19-9) (p < 0.001), lower T stage (p = 0.042), the absence of lymph-node metastasis (p = 0.043), and receiving curative surgery (p = 0.033) were independent predictors of better outcomes.

CONCLUSION

While hepatitis influenced a number of clinical features in ICC patients, it did not affect survival rate. Prognostic factors influencing survival outcomes with ICC were CA 19-9 level, T stage, the presence of lymph node metastasis, and curative surgery.

A Novel Way of Preventing Postoperative Pancreatic Fistula by Directly Injecting Profibrogenic Materials into the Pancreatic Parenchyma

This paper aims to validate if intrapancreatic injection of penicillin G can enhance hardness and suture holding capacity (SHC) of the pancreas through prompting the fibrosis process. Soft pancreatic texture is constantly mentioned as one of the most contributory predictors of postoperative pancreatic fistula (POPF). Soft pancreas has poor SHC and higher incidence of parenchymal tearing, frequently leading to POPF. From a library of 114 antibiotic compounds, we identified that penicillin G substantially enhanced pancreatic hardness and SHC in experimental mice. Specifically, we injected penicillin G directly into the pancreas. On determined dates, we measured the pancreatic hardness and SHC, respectively, and performed molecular and histological examinations for estimation of the degree of fibrosis. The intrapancreatic injection of penicillin G activated human pancreatic stellate cells (HPSCs) to produce various fibrotic materials such as transforming growth factor-β1 (TGF-β1) and metalloproteinases-2. The pancreatic hardness and SHC were increased to the maximum at the second day after injection and then it gradually subsided demonstrating its reversibility. Pretreatment of mice with SB431542, an inhibitor of the TGF-β1 receptor, before injecting penicillin G intrapancreatically, significantly abrogated the increase of both pancreatic hardness and SHC caused by penicillin G. This suggested that penicillin G promotes pancreatic fibrosis through the TGF-β1 signaling pathway. Intrapancreatic injection of penicillin G promotes pancreatic hardness and SHC by enhancing pancreatic fibrosis. We thus think that penicillin G could be utilized to prevent and minimize POPF, after validating its actual effectiveness and safety by further studies.

Stable Subloop Behavior in Ferroelectric Si-Doped HfO2

The recent demand for analogue devices for neuromorphic applications requires modulation of multiple nonvolatile states. Ferroelectricity with multiple polarization states enables neuromorphic applications with various architectures. However, deterministic control of ferroelectric polarization states with conventional ferroelectric materials has been met with accessibility issues. Here, we report unprecedented stable accessibility with robust stability of multiple polarization states in ferroelectric HfO₂. Through the combination of conventional voltage measurements, hysteresis temperature dependence analysis, piezoelectric force microscopy, first-principles calculations, and Monte Carlo simulations, we suggest that the unprecedented stability of intermediate states in ferroelectric HfO₂ is due to the small critical volume size for nucleation and the large activation energy for ferroelectric dipole flipping. This work demonstrates the potential of ferroelectric HfO₂ for analogue device applications enabling neuromorphic computing.

Superior gallstone dissolubility and safety of tert-amyl ethyl ether over methyl-tertiary butyl ether

BACKGROUND

The use of methyl-tertiary butyl ether (MTBE) to dissolve gallstones has been limited due to concerns over its toxicity and the widespread recognition of the safety of laparoscopic cholecystectomy. The adverse effects of MTBE are largely attributed to its low boiling point, resulting in a tendency to evaporate. Therefore, if there is a material with a higher boiling point and similar or higher dissolubility than MTBE, it is expected to be an attractive alternative to MTBE.

AIM

To determine whether tert-amyl ethyl ether (TAEE), an MTBE analogue with a relatively higher boiling point (102 °C), could be used as an alternative to MTBE in terms of gallstone dissolubility and toxicity.

METHODS

The in vitro dissolubility of MTBE and TAEE was determined by measuring the dry weights of human gallstones at predetermined time intervals after placing them in glass containers with either of the two solvents. The in vivo dissolubility was determined by comparing the weights of solvent-treated gallstones and control (dimethyl sulfoxide)-treated gallstones, after the direct infusion of each solvent into the gallbladder in both hamster models with cholesterol and pigmented gallstones.

RESULTS

The in vitro results demonstrated a 24 h TAEE-dissolubility of 76.7%, 56.5% and 38.75% for cholesterol, mixed, and pigmented gallstones, respectively, which represented a 1.2-, 1.4-, and 1.3-fold increase in dissolubility compared to that of MTBE. In the in vitro experiment, the 24 h-dissolubility of TAEE was 71.7% and 63.0% for cholesterol and pigmented gallstones, respectively, which represented a 1.4- and 1.9-fold increase in dissolubility compared to that of MTBE. In addition, the results of the cell viability assay and western blot analysis indicated that TAEE had a lower toxicity towards gallbladder epithelial cells than MTBE.

CONCLUSION

We demonstrated that TAEE has higher gallstone dissolubility properties and safety than those of MTBE. As such, TAEE could present an attractive alternative to MTBE if our findings regarding its efficacy and safety can be consistently reproduced in further subclinical and clinical studies.

A Room-Temperature Ferroelectric Ferromagnet in a 1D Tetrahedral Chain Network

Ferroelectricity occurs in crystals with broken spatial inversion symmetry. In conventional perovskite oxides, concerted ionic displacements within a 3D network of transition-metal-oxygen polyhedra (MO_x ) manifest spontaneous polarization. Meanwhile, some 2D networks of MO_x foster geometric ferroelectricity with magnetism, owing to the distortion of the polyhedra. Because of the fundamentally different mechanism of ferroelectricity in a 2D network, one can further challenge an uncharted mechanism of ferroelectricity in a 1D channel of MO_x and estimate its feasibility. Here, ferroelectricity and coupled ferromagnetism in a 1D FeO₄ tetrahedral chain network of a brownmillerite SrFeO_2.5 epitaxial thin film are presented. The result provides a new paradigm for designing low-dimensional MO_x networks, which is expected to benefit the realization of macroscopic ferro-ordering materials including ferroelectric ferromagnets.

Distinct Clinical Manifestations of Thyroid Cancer After Hematopoietic Stem Cell Transplantation

BACKGROUND

The incidence of a secondary solid malignancy after hematopoietic cell transplantation (HCT) is increasing in long-term survivors.

OBJECTIVE

The aim of this study was to compare the clinicopathological characteristics of HCT recipients with secondary thyroid cancer (STC), with those of non-HCT thyroid cancer patients.

METHODS

We retrospectively investigated 5184 patients who received HCT between 1983 and 2016. Of these, 18 patients developed STC and underwent thyroidectomy due to differentiated thyroid cancer. We compared the clinicopathological characteristics of post-HCT thyroid cancer patients (post-HCT group) with those of a primary differentiated thyroid carcinoma cohort (cohort group) from Seoul St. Mary's Hospital.

RESULTS

The mean ages at HCT and thyroidectomy after HCT were 22.0 and 31.8 years, respectively, and the median time interval between HCT and thyroidectomy was 5 years (range 1-16). Compared with the cohort group, the post-HCT group was younger at cancer onset and frequently had a palpable mass at initial diagnosis. The post-HCT group had more aggressive features, including larger tumor size, frequent extrathyroidal extension, lymphatic invasion, perineural invasion, and frequent lateral neck node metastasis and distant metastasis, relative to the cohort group; however, most patients (83.2%) in the post-HCT group were stage I or II. Additionally, BRAF V600E mutation was less frequent in the post-HCT group.

CONCLUSIONS

We found that STC after HCT showed younger presentation and more aggressive clinical presentation. Therefore, a policy of regular screening, including neck ultrasound examination, may promote early detection and treatment in HCT recipients.

The Role of Phospho-c-Jun N-Terminal Kinase Expression on hepatocyte Necrosis and Autophagy in the Cholestatic Liver

BACKGROUND

Clinically, liver fibrosis and cholestasis are two major disease entities, ultimately leading to hepatic failure. Although autophagy plays a substantial role in the pathogenesis of these diseases, its precise mechanism has not been determined yet.

MATERIALS AND METHODS

Mouse models of liver fibrosis or cholestasis were obtained after the serial administration of thioacetamide (TAA) or surgical bile duct ligation (BDL), respectively. Then, after obtaining liver specimens at specific time points, we compared the expression of makers related to apoptosis (cleaved caspases), inflammation (CD68), necrosis (high-mobility group box 1), phospho-c-Jun N-terminal kinase (p-JNK), and autophagy (microtubule-associated protein light chain 3B and p62) in the fibrotic or cholestatic mouse livers, by polymerase chain reaction, Western blot analysis, immunohistochemistry, and immunofluorescence.

RESULTS

Although cholestatic livers exhibited the tendency of progressively increasing the expression of most apoptosis-related markers (cleaved caspases), it was not prominent when it was compared with the tendency found in the livers of TAA-treated mice. Contrastingly, the necrosis-related factor (high-mobility group box 1) was significantly increased in the livers of BDL mice over time, reaching their peak values on day 7 after BDL. In addition, the inflammation-related factor (CD68) was highly expressed in BDL mice compared with TAA-treated mice over time. Autophagy marker studies indicated that autophagy was upregulated in fibrotic livers, whereas it was downregulated in cholestatic livers. We also observed mild to moderate activation of p-JNK in the livers of TAA-treated mice, whereas significantly higher p-JNK activation was detected in the livers of BDL mice.

CONCLUSIONS

Unlike TAA-treated mice, BDL mice exhibited higher expression of the markers related with inflammation and necrosis, especially including p-JNK, while maintaining low levels of autophagic process. Therefore, obstructive cholestasis is characterized by higher p-JNK activation, which could be related with marked necrotic cell death resulting from extensive inflammation and little chance of compensatory autophagy.

Effects of whole body vibration on spinal proprioception in healthy individuals

BACKGROUND

Low back pain (LBP) is a common health problem with high reoccurrence rate. As patients with LBP are often found to be proprioception impaired, new proprioception exercises should be explored. Whole body vibration (WBV) has been proven to improve muscle function and proprioception.

OBJECTIVE

The aim of this study was to determine the effects of WBV on spinal proprioception when WBV was administered in standing and seated postures.

METHODS

Twenty healthy male individuals (mean age: 23.2±1.2 years) were recruited and randomly assigned to two WBV groups: WBV in standing or WBV in seated posture. Their body posture, lumbar repositioning ability, maximum reaching distance and lumbopelvic coordination during dynamic motion in flexion and extension were assessed before, immediately after, 30 minutes after and 1 hour after 5 minutes of WBV (18 Hz, 6 mm amplitude) exposure. A Mixed ANOVA was used to analyze the effects of group and time factors on these four outcome measures.

RESULTS

There were no significant interaction (group and time) and group effects on all outcome measures. Participants were found to have significant different time effect on body posture, lumbar repositioning ability, maximum reaching distance and lumbopelvic coordination.

CONCLUSIONS

WBV could significantly improve spinal proprioception including body posture, lumbar repositioning ability, maximum reaching distance and lumbopelvic coordination in healthy individuals. WBV protocol is recommended to confirm its clinical application for improving spinal proprioception and its effects on patients with LBP is warranted.

Novel Discovery of LINE-1 in a Korean Individual by a Target Enrichment Method

Long interspersed element-1 (LINE-1 or L1) is an autonomous retrotransposon, which is capable of inserting into a new region of genome. Previous studies have reported that these elements lead to genomic variations and altered functions by affecting gene expression and genetic networks. Mounting evidence strongly indicates that genetic diseases or various cancers can occur as a result of retrotransposition events that involve L1s. Therefore, the development of methodologies to study the structural variations and interpersonal insertion polymorphisms by L1 element-associated changes in an individual genome is invaluable. In this study, we applied a systematic approach to identify human-specific L1s (i.e., L1Hs) through the bioinformatics analysis of high-throughput next-generation sequencing data. We identified 525 candidates that could be inferred to carry non-reference L1Hs in a Korean individual genome (KPGP9). Among them, we randomly selected 40 candidates and validated that approximately 92.5% of non-reference L1Hs were inserted into a KPGP9 genome. In addition, unlike conventional methods, our relatively simple and expedited approach was highly reproducible in confirming the L1 insertions. Taken together, our findings strongly support that the identification of non-reference L1Hs by our novel target enrichment method demonstrates its future application to genomic variation studies on the risk of cancer and genetic disorders.

Ferroelectric Polarization-Switching Dynamics and Wake-Up Effect in Si-Doped HfO2

The ferroelectricity in ultrathin HfO₂ offers a viable alternative to ferroelectric memory. A reliable switching behavior is required for commercial applications; however, many intriguing features of this material have not been resolved. Herein, we report an increase in the remnant polarization after electric field cycling, known as the "wake-up" effect, in terms of the change in the polarization-switching dynamics of a Si-doped HfO₂ thin film. Compared with a pristine specimen, the Si-doped HfO₂ thin film exhibited a partial increase in polarization after a finite number of ferroelectric switching behaviors. The polarization-switching behavior was analyzed using the nucleation-limited switching model characterized by a Lorentzian distribution of logarithmic domain-switching times. The polarization switching was simulated using the Monte Carlo method with respect to the effect of defects. Comparing the experimental results with the simulations revealed that the wake-up effect in the HfO₂ thin film is accompanied by the suppression of disorder.

Simple and Low-Cost Sampling of Cell-Free Nucleic Acids from Blood Plasma for Rapid and Sensitive Detection of Circulating Tumor DNA

Cell-free nucleic acids (cfNAs) are emerging diagnostic biomarkers for monitoring the treatment and recurrence of cancers. In particular, the biological role and clinical usefulness of cfNAs obtained from the plasma of patients with various cancers are popular and still intensely explored, yet most studies are limited by technical problems during cfNA isolation. A dimethyl dithiobispropionimidate (DTBP)-based microchannel platform that enables spontaneous cfNA capture in 15 min with minimal cellular background and no requirements for use of bulky instruments is reported first. This platform identified KRAS and BRAF hot-spot mutations following cfDNA isolation from the blood plasma and tissues obtained from 30 colorectal cancer patients. The correlation of mutations between the primary tissues and plasma from the patients was high using this platform with whole genome sequencing compared to the spin-column method. This platform can also be combined with various detection approaches (biooptical sensor, Sanger sequencing, and polymerase chain reaction (PCR)) for rapid, simple, low-cost, and sensitive circulating tumor DNA detection in blood plasma. The efficiency and versatility of this platform in isolating cfNAs from liquid biopsies has applications in cancer treatment and precision medicine.

CXCR3-deficient mesenchymal stem cells fail to infiltrate into the nephritic kidney and do not ameliorate lupus symptoms in MRL. Faslpr mice

Mesenchymal stem cell therapy is a promising candidate for the treatment of systemic lupus erythematosus (SLE). To exert their efficacy fully, mesenchymal stem cells must infiltrate efficiently into the lesion sites. Here, we examined the role of CXCR3 in mesenchymal stem cell infiltration into the kidney of MRL. Fas^lpr mice, which highly expressed CXCL10. The phenotypes, production of immunosuppressive mediators, and capacity to inhibit T and B cells of CXCR3-deficient mesenchymal stem cells were similar to those of wild-type mesenchymal stem cells. However, they showed less infiltration into the nephritic kidney, less conjugation with endothelial cells and weaker MMP-9 expression than did wild-type mesenchymal stem cells. Consequently, CXCR3-deficient mesenchymal stem cells did not ameliorate lupus symptoms in MRL. Fas^lpr mice in comparison with wild-type mesenchymal stem cells. In summary, our data suggest that upregulation of CXCR3 in mesenchymal stem cells will be a good strategy to increase their infiltration into the kidney, which will improve therapeutic outcomes in SLE.

Using the chronic kidney disease guidelines to evaluate the renal safety of tenofovir disoproxil fumarate in hepatitis B patients

BACKGROUND

Renal dysfunction remains an issue in tenofovir disoproxil fumarate (TDF) for chronic hepatitis B (CHB) patients.

AIM

To evaluate renal safety of TDF according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines.

METHODS

We retrospectively recruited CHB patients who received either TDF or entecavir (ETV) monotherapy from January 2008 to August 2015. After excluding confounding conditions, 253 patients who received TDF were randomly matched 1:2 with 506 patients who received ETV through the propensity scores, which consisted of age, gender, cirrhosis, chronic kidney disease (CKD) and estimated glomerular filtration rate (eGFR). Renal function deterioration was defined as a drop in GFR category accompanied with a ≥25% eGFR decline. Cumulative incidences of and hazard ratios (HRs) for renal dysfunction were analysed.

RESULTS

The mean eGFR decline was significantly greater in the TDF group over 48 months (TDF vs ETV: 15.73 mL/min/1.73 m² , 95% confidence interval [CI]: 13.76-17.70 vs 5.96 mL/min/1.73 m² , 95% CI: 4.72-7.19; P < 0.001). The cumulative incidence of renal function deterioration was significantly higher in the TDF group (TDF vs ETV: 11.1%, 95% CI: 7.4-14.8 vs 1.7%, 95% CI: 1.0-2.4; P < 0.001). After adjusting for age, pre-existing CKD and diabetes, TDF was independently associated with an increased risk of renal function deterioration (HR 5.36, 95% CI: 2.16-13.35; P < 0.001). Pre-existing CKD (HR 6.71, 95% CI: 2.25-17.65), proteinuria (HR 3.39, 95% CI: 1.23-9.39), and haematuria (HR 4.25, 95% CI: 1.32-13.68) were also independent factors of renal dysfunction.

CONCLUSION

By following the KDIGO guidelines, we confirmed that TDF was associated with a higher risk of renal dysfunction as compared to ETV.

Aggressive intravenous hydration with lactated Ringer's solution for prevention of post-ERCP pancreatitis: a prospective randomized multicenter clinical trial

BACKGROUND AND STUDY AIMS : The present study aimed to determine the type of intravenous hydration that is best suited to reducing the incidence of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis.

PATIENTS AND METHODS

In a prospective randomized multicenter trial, average-to-high risk patients who underwent first-time ERCP were randomly assigned to three groups (1:1:1) who received: aggressive intravenous hydration (3 mL/kg/h during ERCP, a 20-mL/kg bolus and 3 mL/kg/h for 8 hours after ERCP) with either lactated Ringer's solution (LRS) or normal saline solution (NSS), or standard intravenous hydration with LRS (1.5 mL/kg/h during and for 8 hours after ERCP). The primary end point was post-ERCP pancreatitis (PEP).

RESULTS

395 patients were enrolled, and 385 completed the protocols. The three groups showed no significant differences in demographic characteristics. There was a significant difference in the intention-to-treat (ITT) PEP rate between the aggressive LRS group (3.0 %, 95 % confidence interval [CI] 0.1 % - 5.9 %; 4 /132), the aggressive NSS group (6.7 %, 95 %CI 2.5 % - 10.9 %; 9 /134) and the standard LRS group (11.6 %, 95 %CI 6.1 % - 17.2 %; 15 /129; P = 0.03). In the two-group comparisons, the ITT PEP rate was significantly lower for the aggressive LRS group than for the standard LRS group (relative risk [RR] 0.26, 95 %CI 0.08 - 0.76; P = 0.008). There was no significant difference in the ITT PEP rate between the aggressive NSS group and the standard LRS group (RR 0.57, 95 %CI 0.26 - 1.27; P = 0.17).

CONCLUSION

Aggressive hydration with LRS is the best approach to intravenous hydration for the prevention of PEP in average-to-high risk patients.

A rapid bio-optical sensor for diagnosing Q fever in clinical specimens

Recent zoonotic outbreaks, such as Zika, Middle East respiratory syndrome and Ebola, have highlighted the need for rapid and accurate diagnostic assays that can be used to aid pathogen control. Q fever is a zoonotic disease caused by the transmission of Coxiella burnetii that can cause serious illness in humans through aerosols and is considered a potential bioterrorism agent. However, the existing assays are not suitable for the detection of this pathogen due to its low levels in real samples. We here describe a rapid bio-optical sensor for the accurate detection of Q fever and validate its clinical utility. By combining a bio-optical sensor, that transduces the presence of the target DNA based on binding-induced changes in the refractive index on the waveguide surface in a label-free and real-time manner, with isothermal DNA amplification, this new diagnostic tool offers a rapid (<20 min), 1-step DNA amplification/detection method. We confirmed the clinical sensitivity (>90%) of the bio-optical sensor by detecting C. burnetii in 11 formalin-fixed, paraffin-embedded liver biopsy samples from acute Q fever hepatitis patients and in 16 blood plasma samples from patients in which Q fever is the cause of fever of unknown origin.