Cough Response to High-Dose Inhaled Corticosteroids in Patients with Chronic Cough and Fractional Exhaled Nitric Oxide Levels ≥ 25 ppb: A Prospective Study

This study aimed to investigate the effects of high-dose inhaled corticosteroids (ICS) on chronic cough patients with elevated fractional exhaled nitric oxide (FeNO) levels. In a prospective study, adults with chronic cough and FeNO ≥ 25 ppb, without any other apparent etiology, received fluticasone furoate (200 mcg) for three weeks. Outcomes were evaluated using FeNO levels, cough severity, and Leicester Cough Questionnaire (LCQ) before and after treatment. Of the fifty participants (average age: 58.4 years; 58% female), the treatment responder rate (≥ 1.3-point increase in LCQ) was 68%, with a significant improvement in cough and LCQ scores and FeNO levels post-treatment. However, improvements in cough did not significantly correlate with changes in FeNO levels. These findings support the guideline recommendations for a short-term ICS trial in adults with chronic cough and elevated FeNO levels, but the lack of correlations between FeNO levels and cough raises questions about their direct mechanistic link.

Characterization of Codeine Treatment Responders Among Patients with Refractory or Unexplained Chronic Cough: A Prospective Real-World Cohort Study

PURPOSE

Codeine is a narcotic antitussive often considered for managing patients with refractory or unexplained chronic cough. This study aimed to evaluate the proportion and characteristics of patients who responded to codeine treatment in real-world practice.

METHODS

Data from the Korean Chronic Cough Registry, a multicenter prospective cohort study, were analyzed. Physicians assessed the response to codeine based on the timing and degree of improvement after treatment initiation. Follow-up assessments included the Leicester Cough Questionnaire and cough severity visual analog scale at six months. In a subset of subjects, objective cough frequency was evaluated following the initiation of codeine treatment.

RESULTS

Of 305 patients, 124 (40.7%) responded to treatments based on anatomic diagnostic protocols, while 181 (59.3%) remained unexplained or refractory to etiological treatments. Fifty-one subjects (16.7%) were classified as codeine treatment responders (those showing a rapid and clear response), 57 (18.7%) as partial responders, and 62 (20.3%) as non-responders. Codeine responders showed rapid improvement in objective cough frequency and severity scores within a week of the treatment. At 6 months, responders showed significantly improved scores in cough scores, compared to non-responders. Several baseline parameters were associated with a more favorable treatment response, including older age, non-productive cough, and the absence of heartburn.

CONCLUSIONS

Approximately 60% of chronic cough patients in specialist clinics may require antitussive drugs. While codeine benefits some, only a limited proportion (about 20%) of patients may experience rapid and significant improvement. This underscores the urgent need for new antitussive drugs to address these unmet clinical needs.

Development of a Prognostic Scoring System for Tracheostomized Patients Requiring Prolonged Ventilator Care: A Ten-Year Experience in a University-Affiliated Tertiary Hospital

Background and Objectives: This study aimed to assess the value of a novel prognostic model, based on clinical variables, comorbidities, and demographic characteristics, to predict long-term prognosis in patients who received mechanical ventilation (MV) for over 14 days and who underwent a tracheostomy during the first 14 days of MV. Materials and Methods: Data were obtained from 278 patients (66.2% male; median age: 71 years) who underwent a tracheostomy within the first 14 days of MV from February 2011 to February 2021. Factors predicting 1-year mortality after the initiation of MV were identified by binary logistic regression analysis. The resulting prognostic model, known as the tracheostomy-ProVent score, was computed by assigning points to variables based on their respective ß-coefficients. Results: The overall 1-year mortality rate was 64.7%. Six factors were identified as prognostic indicators: platelet count < 150 × 103/μL, PaO2/FiO2 < 200 mmHg, body mass index (BMI) < 23.0 kg/m2, albumin concentration < 2.8 g/dL on day 14 of MV, chronic cardiovascular diseases, and immunocompromised status at admission. The tracheostomy-ProVent score exhibited acceptable discrimination, with an area under the receiver operating characteristic curve (AUC) of 0.786 (95% confidence interval: 0.733-0.833, p < 0.001) and acceptable calibration (Hosmer-Lemeshow chi-square: 2.753, df: 8, p = 0.949). Based on the maximum Youden index, the cut-off value for predicting mortality was set at ≥2, with a sensitivity of 67.4% and a specificity of 76.3%. Conclusions: The tracheostomy-ProVent score is a good predictive tool for estimating 1-year mortality in tracheostomized patients undergoing MV for >14 days. This comprehensive model integrates clinical variables and comorbidities, enhancing the precision of long-term prognosis in these patients.

Ability of the modified NUTRIC score to predict mortality in patients requiring short-term versus prolonged acute mechanical ventilation: a retrospective cohort study

BACKGROUND

The modified NUTRIC (nutritional risk in the critically ill) score has been reported to predict clinical outcomes in critically ill patients. However, the applicability of this score may differ between patients undergoing short-term mechanical ventilation (STMV, < 96 h) and those undergoing prolonged acute mechanical ventilation (PAMV, ⩾96 h), as PAMV patients typically experience significantly higher morbidity and mortality.

OBJECTIVE

This study aimed to investigate the predictive ability of modified NUTRIC score for predicting 28-day mortality in patients receiving STMV and PAMV.

DESIGN

Retrospective single-center cohort study.

METHODS

We enrolled patients who received mechanical ventilation (MV) on the day of admission to the intensive care unit (ICU) from 1 December 2015 to 30 November 2020. Modified NUTRIC scores were calculated based on the clinical data of each patient at ICU admission.

RESULTS

The study population comprised 464 patients, including 319 (68.8%) men with a mean age of 69.7 years. Among these patients, 132 (28.4%) received STMV and 332 (71.6%) received PAMV. The overall 28-day mortality rate was 26.7%, which was significantly higher in STMV patients than in PAMV patients (37.9% versus 22.3%, p < 0.001). Evaluation of the predictive performance of the modified NUTRIC score for 28-day mortality revealed areas under the receiver operating characteristic curves of 0.672 [95% confidence interval (CI): 0.627-0.714] for total patients, 0.819 (95% CI, 0.742-0.880) for STMV patients, and 0.595 (95% CI, 0.540-0.648) for PAMV patients. The best overall cutoff value was 5 in total, STMV, and PAMV patients. This cutoff value was a significant predictor of 28-day mortality based on the Cox proportional hazard model for total [hazards ratio (HR): 2.681; 95% CI: 1.683-4.269] and STMV (HR: 5.725; 95% CI: 2.057-15.931) patients, but not for PAMV patients.

CONCLUSION

The modified NUTRIC score is more effective in predicting 28-day mortality in patients undergoing STMV than in those undergoing PAMV.

Baseline Cohort Profile of the Korean Chronic Cough Registry: A Multicenter, Prospective, Observational Study

PURPOSE

The Korean Chronic Cough Registry study was initiated to characterize patients with chronic cough (CC) and investigate their outcomes in real-world clinical practice. This report aims to describe the baseline cohort profile and study protocols.

METHODS

This multicenter, prospective observational cohort study included newly referred CC patients and those already being treated for refractory or unexplained chronic cough (RUCC). Cough status was assessed using a visual analog scale, the Leicester Cough Questionnaire (LCQ), and the Cough Hypersensitivity Questionnaire (CHQ).

RESULTS

A total of 610 patients (66.9% women; median age 59.0 years) were recruited from 18 centers, with 176 being RUCC patients (28.9%). The median age at CC onset was 50.1 years, and 94.4% had adult-onset CC (≥ 19 years). The median cough duration was 4 years. Compared to newly referred CC patients, RUCC patients had a longer cough duration (6.0 years vs. 3.0 years) but had fewer symptoms and signs suggesting asthma, rhinosinusitis, or gastroesophageal acid reflux disease. Subjects with RUCC had lower LCQ scores (10.3 ± 3.3 vs. 11.6 ± 3.6; P < 0.001) and higher CHQ scores (9.1 ± 3.9 vs. 8.4 ± 4.1; P = 0.024). There were no marked differences in the characteristics of cough between refractory chronic cough and unexplained chronic cough.

CONCLUSIONS

Chronic cough typically develops in adulthood, lasting for years. Cough severity and quality of life impairment indicate the presence of unmet clinical needs and insufficient cough control in real-world clinical practice. Longitudinal follow-up is warranted to investigate the natural history and treatment outcomes.

Clinical outcomes of transbronchial cryobiopsy using a 1.1-mm diameter cryoprobe for peripheral lung lesions - A prospective pilot study

OBJECTIVES

Transbronchial cryobiopsy (TBCB) is a novel technique for the diagnosis of peripheral lung lesions (PLLs). We aim to evaluate the clinical outcomes of TBCB using a new 1.1-mm diameter cryoprobe for the diagnosis of PLLs.

MATERIALS AND METHODS

We performed a prospective observational pilot study on the diagnosis of PLLs (diameter ≤30 mm) by TBCB, using a 1.1-mm diameter cryoprobe with radial endobronchial ultrasound (RP-EBUS), virtual bronchoscopic navigation and fluoroscopy from December 2021 to July 2022. Primary outcome was the pathological diagnostic yield of TBCB, and secondary outcome was adverse event.

RESULTS

A total of 50 patients were enrolled (mean lesion size, 21 mm). TBCB was performed in 49 patients up to three times except for the one with "invisible" finding on RP-EBUS. The overall diagnostic yield of TBCB was 90% (45/50). There was no difference in the diagnostic yield between size (20 mm vs. 20-30 mm; 88% [22/25] vs. 92% [23/25]; P = 1.000), RP-EBUS findings (concentric vs. others; 97% [28/29] vs. 81% [17/21]; P = 0.148), and acute angle location (apical segment of both upper lobes vs. others; 92% [12/13] vs. 89% [33/37]; P = 1.000). The cumulative diagnostic yields of the first, second, and third TBCB were 82% (41/50), 88% (44/50), and 90% (45/50), respectively. Mild bleeding was developed in 56% (28/50), and moderate bleeding was found in 26% (13/50).

CONCLUSION

TBCB using a 1.1-mm diameter cryoprobe is an effective, reasonable method for the diagnosis of PLLs regardless of its size, RP-EBUS finding, and anatomical location without serious complication.

TRIAL REGISTRATION

Clinical Trials.Gov (NCT05046093).

Plasmonic Approach to Fluorescence Enhancement of Mesoporous Silica-Coated Gold Nanorods for Highly Sensitive Influenza A Virus Detection Using Lateral Flow Immunosensor

Rapid diagnostic tests based on the lateral flow immunoassay (LFI) enable early identification of viral infection, owing to simple interpretation, short turnaround time, and timely isolation of patients to minimize viral transmission among communities. However, the LFI system requires improvement in the detection sensitivity to match the accuracy of nucleic acid amplification tests. Fluorescence-based LFIs are more sensitive and specific than absorption-based LFIs, but their performance is significantly affected by fundamental issues related to the quantum yield and photobleaching of fluorophores. Metal-enhanced fluorescence (MEF), which is a plasmonic effect in the vicinity of metallic nanoparticles, can be an effective strategy to improve the detection sensitivity of fluorescence-based LFIs. The key factors for obtaining a strong plasmonic effect include the distance and spectral overlap of the metal and fluorophore in the MEF system. In this study, MEF probes were designed based on core-shell nanostructures employing a gold nanorod core, mesoporous silica shell, and cyanine 5 fluorophore. To optimize the efficiency of MEF probes incorporated on the LFI platform (MEF-LFI), we experimentally and theoretically investigated the distance dependence of plasmonic coupling between cyanine 5 and gold nanorods by adjusting the shell thickness, resulting in significant fluorescence enhancement. The proposed MEF-LFI enabled highly sensitive detection of influenza A virus (IAV) nucleocapsid protein with a detection limit of 0.52 pg mL-1 within 20 min and showed high specificity and accuracy for determining IAV clinical samples. Overall, our findings demonstrate the potential of this method as an effective tool for molecular diagnosis under emergency conditions.

Health-Related Quality of Life and Its Determinants in Chronic Cough: The Korean Chronic Cough Registry Study

PURPOSE

Chronic cough (CC) is associated with health-related quality of life (HRQoL) impairment. However, the determinants of HRQoL are under-investigated.

METHODS

Patients aged 19-80 years with CC were prospectively recruited from 10 referral clinics. Comparisons were made with age- and sex-matched controls (1:4 ratio) selected from a Korean general population survey database; 1) a group without current cough (non-cough controls) and 2) another group without major chronic illnesses (healthy controls). HRQoL was assessed using the EuroQoL 5-dimension (EQ-5D) index. In CC patients, cough-specific patient-reported outcomes (PROs) were additionally measured. Cross-sectional analyses were performed to evaluate demographic and clinical parameters associated with the EQ-5D index of CC patients.

RESULTS

A total of 200 CC patients (137 newly referred with CC and 63 refractory or unexplained CC [RUCC] patients), 800 non-cough controls, and 799 healthy controls were analyzed. The EQ-5D index of CC patients was significantly lower than that of non-cough controls or healthy controls (0.82 ± 0.14 vs 0.92 ± 0.14/0.96 ± 0.08; P < 0.001, respectively). The index was also associated with older age (≥ 60 years), female sex, and comorbidities such as asthma or depression. Among the patients with CC, the index was significantly lower in patients with RUCC than in those with newly referred CC, being treated with codeine or cough neuromodulators, or with cough-related fatigue. In Spearman analyses, the EQ-5D index correlated with cough-specific quality of life and cough severity scores, not with throat sensation or cough trigger scores.

CONCLUSIONS

The HRQoL impairment of CC patients was associated with older age, female sex, and comorbidities but it was also affected by cough severity, complications, treatments, and treatment responses. Longitudinal studies are warranted to further understand and improve the HRQoL of CC patients.

The Additive Impact of Transbronchial Cryobiopsy Using a 1.1-mm Diameter Cryoprobe on Conventional Biopsy for Peripheral Lung Nodules

PURPOSE

The diagnostic yield of transbronchial biopsy (TBB) using radial probe endobronchial ultrasound (RP-EBUS) is 71%, which is lower than that of transthoracic needle biopsy. We investigated the performance and safety of sequential transbronchial cryobiopsy (TBC) using a novel 1.1-mm diameter cryoprobe, after conventional TBB using RP-EBUS for the diagnosis of peripheral lung lesions (PLLs).

Materials and Methods

From April 2021 to November 2021, 110 patients who underwent bronchoscopy using RP-EBUS for the diagnosis of PLL ≤ 30 mm were retrospectively included in our study. All records were followed until June 2022.

RESULTS

The overall diagnostic yield of combined TBB and TBC was 79.1%, which was higher than 60.9% of TBB alone (p=0.005). The diagnostic yield of sequential TBC was 65.5%, which increased the overall diagnostic yield by 18.2%. The surface area of tissues by TBC (mean area, 18.5 mm2) was significantly larger than those of TBB by 1.5-mm forceps (3.4 mm2, p < 0.001) and 1.9-mm forceps (3.7 mm2, p=0.011). In the multivariate analysis, PLLs with the longest diameter of ≤ 22 mm were found to be related to additional diagnostic benefits from sequential TBC (odds ratio, 3.51; 95% confidence interval, 1.043 to 11.775; p=0.042). Complications were found in 10.5% of the patients: pneumothorax (1.0%), infection (1.0%), and significant bleeding (8.6%). None of the patients developed any life-threatening complications.

CONCLUSION

Sequential TBC with a 1.1-mm cryoprobe improved the performance of conventional TBB using RP-EBUS without serious complications.

Association between participation in a rehabilitation program and 1-year survival in patients requiring prolonged mechanical ventilation

BACKGROUND

The present study evaluated the association between participation in a rehabilitation program during a hospital stay and 1-year survival of patients requiring at least 21 days of mechanical ventilation (prolonged mechanical ventilation [PMV]) with various respiratory diseases as their main diagnoses that led to mechanical ventilation.

METHODS

Retrospective data of 105 patients (71.4% male, mean age 70.1±11.3 years) who received PMV in the past 5 years were analyzed. Rehabilitation included physiotherapy, physical rehabilitation, and dysphagia treatment program that was individually provided by physiatrists.

RESULTS

The main diagnosis leading to mechanical ventilation was pneumonia (n=101, 96.2%) and the 1-year survival rate was 33.3% (n=35). One-year survivors had lower Acute Physiology and Chronic Health Evaluation (APACHE) II score (20.2±5.8 vs. 24.2±7.5, p=0.006) and Sequential Organ Failure Assessment score (6.7±5.6 vs. 8.5±2.7, p=0.001) on the day of intubation than non-survivors. More survivors participated in a rehabilitation program during their hospital stays (88.6% vs. 57.1%, p=0.001). The rehabilitation program was an independent factor for 1-year survival based on the Cox proportional hazard model (hazard ratio, 3.513; 95% confidence interval, 1.785 to 6.930; p&lt;0.001) in patients with APACHE II scores ≤23 (a cutoff value based on Youden's index).

CONCLUSION

Our study showed that participation in a rehabilitation program during hospital stay was associated with an improvement of 1-year survival of PMV patients who had less severe illness on the day of intubation.

The prevalence of multiple chronic conditions and medical burden in asthma patients

BACKGROUND

The prevalence of multiple chronic conditions (MCC), defined as several coexisting chronic conditions, has increased with the aging of society. MCC is associated with poor outcomes, but most comorbid diseases in asthma patients have been evaluated as asthma-associated diseases. We investigated the morbidity of coexisting chronic diseases in asthma patients and their medical burdens.

METHODS

We analyzed data from the National Health Insurance Service-National Sample Cohort for 2002-2013. We defined MCC with asthma as a group of one or more chronic diseases in addition to asthma. We analyzed 20 chronic conditions, including asthma. Age was categorized into groups 1-5 (< 10, 10-29, 30-44, 45-64, and ≥ 65 years, respectively). The frequency of medical system use and associated costs were analyzed to determine the asthma-related medical burden in patients with MCC.

RESULTS

The prevalence of asthma was 13.01%, and the prevalence of MCC in asthmatic patients was 36.55%. The prevalence of MCC with asthma was higher in females than males and increased with age. The significant comorbidities were hypertension, dyslipidemia, arthritis, and diabetes. Dyslipidemia, arthritis, depression, and osteoporosis were more common in females than males. Hypertension, diabetes, COPD, coronary artery disease, cancer, and hepatitis were more prevalent in males than females. According to age, the most prevalent chronic condition in groups 1 and 2 was depression, dyslipidemia in group 3, and hypertension in groups 4 and 5. Older age, low income, and severe disability were independent risk factors for MCC in patients with asthma. The frequency of asthma-related medical system use and asthma-associated costs increased with increasing numbers of coexisting chronic diseases.

CONCLUSION

Comorbid chronic diseases in asthma patients differed according to age and sex. The asthma-related-medical burdens were highest in patients with five or more chronic conditions and groups 1 and 5.

Idiopathic Hypereosinophilia: A Multicenter Retrospective Analysis

PURPOSE

Physicians can sometimes encounter idiopathic hypereosinophilia (HE), but little is known about it. In this multicenter study, we analyzed the clinical characteristics, treatment, and outcomes of patients with idiopathic HE.

PATIENTS AND METHODS

Patients diagnosed with idiopathic HE (idiopathic hypereosinophilic syndrome: iHES or hypereosinophilia with undetermined significance: HEus) at six tertiary hospitals between January 2010 and June 2021 were included in this retrospective observational study. Demographics, clinical and laboratory data, and treatment responses were obtained from the electronic medical records of the study subjects.

RESULTS

A total of 73 patients with idiopathic HE (45 with iHES and 28 with HEus) were included in the present study. Overall, 12 (26.7%) and 5 (17.9%) were women, and mean age of patients at diagnosis was 51.84 ± 17.29 years and 60.21 ± 18.01 years in iHES and HEus groups, respectively. Forty-three (95.6%) patients of iHES and 15 (53.6%) patients of HEus received corticosteroids as 1st-line treatment. Treatment response to corticosteroids in patients with iHES was generally good: complete response (n=25, 58.1%), partial response (n=12, 27.9%), no response (n=6, 14.0%). Treatment response to corticosteroids in HEus was complete response (n=7, 46.7%), partial response (n=6, 40.0%), and no response (n=2, 13.3%). There were 13 patients (46.4%) with HEus who were not treated.

CONCLUSION

Corticosteroid treatment is generally effective and well tolerated by patients with iHES. Some patients with HEus are treated with corticosteroids in clinical practice. Extensive research is needed to establish a standardized management guidelines for iHES and determine whether treatment for HEus is required.

Absorption-Modulated SiO2@Au Core-Satellite Nanoparticles for Highly Sensitive Detection of SARS-CoV-2 Nucleocapsid Protein in Lateral Flow Immunosensors

The worldwide spread of coronavirus disease 2019 (COVID-19) highlights the need for rapid, simple, and accurate tests to detect various variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The antigen test, based on the lateral flow immunoassay (LFI), is a suitable "first line of defense" test that enables early identification and timely isolation of patients to minimize viral transmission among communities. However, it is generally less accurate than nucleic acid testing, and its sensitivity needs improvement. Here, a novel rapid detection method is designed to sensitively detect SARS-CoV-2 using isolated gold nanoparticle (AuNP)-assembled SiO2 core-satellite nanoparticles (SiO2@Au CSNPs). Well-grown AuNP satellites in the synthesis of SiO2@Au CSNPs significantly enhanced their light absorption, increased the detection sensitivity, and lowered the detection limit by 2 orders of magnitude relative to conventional gold colloids. The proposed system enabled highly sensitive detection of the SARS-CoV-2 nucleocapsid protein with a detection limit of 0.24 pg mL-1 within 20 min. This is the first study to develop a highly sensitive antigen test using the absorption-modulated SiO2@Au CSNPs. Our findings demonstrate the capacity of this platform to serve as an effective sensing strategy for managing pandemic conditions and preventing the spread of viral infections.

The First Case of Erythritol-Induced Anaphylaxis in Korea

Erythritol is a natural sugar alcohol found in some fruits and fermented foods, which is used as a dietary sweetener because it has few calories. Here, we describe a 36-year-old woman who experienced anaphylaxis upon ingestion of an erythritol-containing drink. She presented to the emergency department with dyspnea and angioedema after drinking a peach-containing diet beverage. Her blood pressure dropped to 70/40 mmHg and the symptoms improved after administration of an antihistamine, glucocorticoid, and epinephrine. After 10 days, she drank another peach-containing diet beverage and experienced urticaria. No serum-specific immunoglobulin E findings were observed, including against peach components. A skin prick test (SPT) was performed using a peach, the two ingested diet beverages, and another peach-containing beverage. The SPT results for the peach and the peach-containing product were negative, but the wheal sizes for the two diet beverages were > 3 mm. The diet beverages contained erythritol as a food additive. The SPT result was positive for erythritol. The patient was diagnosed with anaphylaxis to erythritol and was instructed to avoid foods containing erythritol. She was prescribed a self-injectable epinephrine pen. To our knowledge, this is the first case of erythritol-induced anaphylaxis in Korea. Physicians should be aware of the possibility of allergic reactions to food additives, and additives should be evaluated to prevent the recurrence of symptoms.

Association Between Clinical Burden and Blood Eosinophil Counts in Asthma: Findings From a Korean Adult Asthma Cohort

BACKGROUND

Some reports have suggested that the clinical and economic burdens of asthma are associated with blood eosinophil levels. The association between clinical burden and blood eosinophil counts were evaluated in a Korean adult asthma cohort.

METHODS

Clinical information including blood eosinophil counts that were not affected by systemic corticosteroids were extracted from the Cohort for Reality and Evolution of Adult Asthma in Korea database. Clinical burden was defined as 1) asthma control status, 2) medication demand and 3) acute exacerbation (AE) events during 1 consecutive year after enrollment. All patients were divided into atopic and non-atopic asthmatics. The associations between asthma outcomes and the blood eosinophil count were evaluated.

RESULTS

In total, 302 patients (124 atopic and 178 non-atopic asthmatics) were enrolled. In all asthmatics, the risk of severe AE was higher in patients with blood eosinophil levels < 100 cells/µL than in patients with levels ≥ 100 cells/µL (odds ratio [OR], 5.406; 95% confidence interval [CI], 1.266-23.078; adjusted P = 0.023). Among atopic asthmatics, the risk of moderate AE was higher in patients with blood eosinophil levels ≥ 300 cells/µL than in patients with levels < 300 cells/µL (OR, 3.558; 95% CI, 1.083-11.686; adjusted P = 0.036). Among non-atopic asthmatics, the risk of medication of Global Initiative for Asthma (GINA) steps 4 or 5 was higher in patients with high blood eosinophil levels than in patients with low blood eosinophil levels at cutoffs of 100, 200, 300, 400, and 500 cells/µL.

CONCLUSION

The baseline blood eosinophil count may predict the future clinical burden of asthma.

Patterns of medical care utilization according to environmental factors in asthma and chronic obstructive pulmonary disease patients

BACKGROUND/AIMS

Weather and air pollution are associated with the exacerbation of respiratory diseases. We investigated patterns of medical care use according to meteorological factors and air pollution in patients with asthma or chronic obstructive pulmonary disease (COPD).

METHODS

We analyzed the medical care utilization patterns of patients with asthma or COPD registered in the Korea Health Insurance Review and Assessment database for the period 2007 to 2013. The patterns were divided into hospitalization and emergency department (ED) use.

RESULTS

The medical care use of patients with asthma or COPD increased when the mean temperature and relative humidity were lower, and the temperature difference and atmospheric pressure were greater. Medical care use increased with the concentrations of particulate matter and ozone. Among age groups, sensitivity to pollutants was greatest in patients aged ≥ 65 years. The effect of being elderly was greater for asthma than for COPD, with a higher hospitalization rate. ED utilization affected by environmental factors was significantly greater for females and hospitalization was significantly more common for males.

CONCLUSION

Meteorological factors and air pollutants were shown to contribute to increased medical care utilization by patients with asthma and COPD, particularly elderly patients. The overall effect was greater for COPD, but the effect in elderly patients was greater for asthma. In addition, the patterns of change in medical care use due to environmental factors differed according to sex.

Electrochemiluminescence-Incorporated Lateral Flow Immunosensors Using Ru(bpy)32+-Labeled Gold Nanoparticles for the Full-Range Detection of Physiological C-Reactive Protein Levels

C-reactive protein (CRP) is used as a general biomarker for inflammation and infection. During stroke and myocardial infarction, CRP increases and is present in a broad concentration range of 1-500 μg/mL. Therefore, full-range CRP detection is crucial to identify patients who need close follow-up or intensive treatment after a heart attack. Here, we report the first attempt to develop an electrochemiluminescent lateral flow immunosensor (ECL-LFI) that allows full-range CRP detection. Ru(bpy)₃²⁺-labeled gold nanoparticles (AuNPs) are used as a CRP-targeting probe and a signal generator; they form sandwich immunocomplexes at the test line of the strip and generate strong ECL emission via a Ru(bpy)₃²⁺/tripropylamine system. The ECL-LFI shows high sensitivity in detecting CRP in spiked serum, with a limit of detection of 4.6 pg/mL within 15 min, and a broad detection range of 0.01-1000 ng/mL, which is 2 orders of magnitude broader than that of conventional colorimetric LFI. The clinical usability of the ECL-LFI was evaluated using 30 clinical serum samples (200 ng/mL to 5 mg/mL), which showed a good linear correlation (R² = 0.9896), with a clinical chemistry analyzer. The results suggest that the ECL-LFI holds great potential for CRP detection in point-of-care diagnostics.

Reactant/polymer hybrid films on p-n junction photodetectors for self-powered, non-invasive glucose biosensors

The portability of electronic-based biosensors is limited because of the use of batteries and/or solutions containing reactants such as enzymes for assay, which limits the utility of such biosensors in point-of-care (POC) testing. In this study, we report on the development of a self-powered biosensor composed of only portable components: a reactant-containing poly (ethylene glycol) (PEG) film for the colorimetric assay, and a self-powered n-InGaZnO/p-Si photodetector. The PEG film containing enzymes and color-developing agents was formed on a glass slide by spin coating. The self-powered biosensor was fabricated by placing the hybrid film on the p-n junction photodetector, and applied in non-invasive glucose detection (salivary glucose). Injection of the target-containing solution dissolved the PEG that led to the release of enzymes and color-developing agents, resulting in a colorimetric assay. The colorimetric assay could attenuate the light reaching the photodetector, thus facilitating target concentration verification by measuring the photocurrent. Our self-powered biosensor has two main advantages: (i) all components of the biosensor are portable and (ii) dilution of target concentration is avoided as the reagents are in the PEG film. Therefore, the self-powered biosensor, without solution-phase components, could be highly beneficial for creating portable, sensitive biosensors for POC testing.

Ru(bpy)32+ -Loaded Mesoporous Silica Nanoparticles as Electrochemiluminescent Probes of a Lateral Flow Immunosensor for Highly Sensitive and Quantitative Detection of Troponin I

The lateral flow immunosensor (LFI) is a widely used diagnostic tool for biomarker detection; however, its sensitivity is often insufficient for analyzing targets at low concentrations. Here, an electrochemiluminescent LFI (ECL-LFI) is developed for highly sensitive detection of troponin I (TnI) using Ru(bpy)₃²⁺ -loaded mesoporous silica nanoparticles (RMSNs). A large amount of Ru(bpy)₃²⁺ is successfully loaded into the mesoporous silica nanoparticles with excellent loading capacity and shows strong ECL signals in reaction to tripropylamine. Antibody-immobilized RMSNs are applied to detect TnI by fluorescence and ECL analysis after a sandwich immunoassay on the ECL-LFI strip. The ECL-LFI enables the highly sensitive detection of TnI-spiked human serum within 20 min at femtomolar levels (≈0.81 pg mL^-1 ) and with a wide dynamic range (0.001-100 ng mL^-1 ), significantly outperforming conventional fluorescence detection (>3 orders of magnitude). Furthermore, TnI concentrations in 35 clinical serum samples across a low range (0.01-48.31 ng mL^-1 ) are successfully quantified with an excellent linear correlation (R²  = 0.9915) using a clinical immunoassay analyzer. These results demonstrate the efficacy of this system as a high-performance sensing strategy capable of capitalizing on future point-of-care testing markets for biomolecule detection.

Anxiety, depression, and stress in Korean patients with chronic urticaria

BACKGROUND/AIMS

Emotional distress is thought to cause or maintain chronic urticaria (CU). We aimed to investigate the presence of anxiety, depression, and stress in Korean adult CU patients and to explore their potential impact on treatment.

METHODS

We enrolled 79 CU patients and a disease control group comprising 39 persistent asthma patients. The Hospital Anxiety and Depression Scale (HADS) was used to evaluate depression and anxiety. Stress and quality of life (QoL) were assessed by Stress Response Inventory and CU-QoL questionnaires. The sociodemographic and clinical data such as urticaria activity score (UAS-15, UAS-6) were obtained.

RESULTS

The prevalence of depression and anxiety based on the HADS were 48.1% and 38.0%. Although the prevalence of anxiety didn't differ between the CU and asthma patients, depression was significantly more prevalent in the CU patients (48.1% vs. 28.2%). Stress tended to be lower in CU patients. Anxiety, depression, and stress exhibited negative correlations with QoL. Anxiety showed significant correlation with UAS-6 and pruritus-visual analog scale (VAS; r = 0.256, r = 0.272, p < 0.05, respectively); depression correlated with sleep difficulty-VAS (r = 0.261, p < 0.05). Stress was associated with UAS-15, UAS-6, pruritus-VAS, and sleep difficulty-VAS (r = 0.251, r = 0.317, r = 0.302, r = 0.258, p < 0.05, respectively).

CONCLUSION

The current study first presented that Korean CU patients frequently have anxiety and depression, which affect their QoL and demonstrated that anxiety, depression, and stress had different effects on sleep difficulty, pruritus, and urticaria severity in Korean CU patients.

Treatment Outcomes of Patients with Multidrug-Resistant Tuberculosis: Comparison of Pre- and Post-Public-Private Mix Periods

BACKGROUND

This study compared the treatment outcomes of patients with multidrug-resistant tuberculosis (MDR-TB) before and after the implementation of public-private mix (PPM). Factors affecting treatment success were also investigated.

METHODS

Data from culture-confirmed pulmonary MDR-TB patients who commenced MDR-TB treatment at Pusan National University Hospital between January 2003 and December 2017 were retrospectively reviewed. Patients were divided into two groups in terms of PPM status: pre-PPM period, patients who commenced MDR-TB treatment between 2003 and 2010; and post-PPM period, patients treated between 2011 and 2017.

RESULTS

A total of 176 patients were included (64 and 112 in the pre- and post-PPM periods, respectively). 36.9% of the patients were resistant to a fluoroquinolone or a second-line injectable drug, or both. The overall treatment success rate was 72.7%. The success rate of post-PPM patients was higher than that of pre-PPM patients (79.5% vs. 60.9%, p=0.008). Also, loss to follow-up was lower in the post-PPM period (5.4% vs. 15.6%, p=0.023). In multivariate regression analysis, age ≥65 years, body mass index ≤18.5 kg/m2, previous TB treatment, bilateral lung involvement, and extensively drug-resistant (XDR)- or pre-XDR-TB were associated with poorer treatment outcomes. However, the use of bedaquiline or delamanid for ≥1 month increased the treatment success.

CONCLUSION

The treatment success rate in MDR-TB patients was higher in the post-PPM period than in the pre-PPM period, particularly because of the low rate of loss to follow-up. To ensure comprehensive patient-centered PPM in South Korea, investment and other support must be adequate.

Plasmon enhanced up-conversion nanoparticles in perovskite solar cells for effective utilization of near infrared light

As an alternative to silicon-based solar cells, organic-inorganic hybrid perovskite solar cells (PSCs) have attracted much attention and achieved a comparable power conversion efficiency (PCE) to silicon-based ones, although the perovskite materials can absorb only visible light. Hence, the challenge remains to enhance the PCE utilizing near infrared (NIR) light in the solar light spectrum. One of the easiest ways to utilize the NIR is to incorporate NIR active materials in PSCs such as up-conversion nanoparticles (UCNPs); however, such a stratergy is not simple to adopt in PSCs due to the inherent vurnerability of perovskite materials towards moisture. In this work, we present NIR-utilizing PSCs by locating UCNPs within the PSC structure by a simple dry transfer method. A maximum PCE of 15.56% was obtained in the case of PSC having the UCNPs located between the hole transport layer (HTL) and gold (Au) top electrode, which is an 8.4% enhancement compared to the cell without the UCNPs. This enhancement came from the combined effects of NIR light utilization and the surface plasmon resonance (SPR) phenomenon originating from the Au top electrode, which was interfacing the UCNPs.

Gold nanocap-supported upconversion nanoparticles for fabrication of a solid-phase aptasensor to detect ochratoxin A

Solid-phase, single-step biosensors are crucial for the development of portable, reusable, and convenient biosensors, otherwise known as point-of-care (POC) testing. Although high-performance single-step biosensors based on the principle of Förster resonance energy transfer (FRET) and using upconversion nanoparticles (UCNPs) functionalized with aptamers have been suggested as easy-to-use platforms, they lack portability and reusability when used for solution-phase biosensing. In this study, we describe a solid-phase, single-step aptasensor that showed higher performance than those of solution-phase aptasensors, as well as promising reusability. The solid-phase, single-step aptasensor was developed based on Au nanocap-supported UCNPs (Au/UCNPs), which were partially embedded in a solid substrate (e.g. polydimethylsiloxane, PDMS). The Au nanocaps allowed the UCNPs to emit upconverted light only from the restricted areas of the UCNPs, i.e., where they were not covered by the nanocaps and PDMS. Functionalization of an aptamer labeled with a quencher on the restricted area enabled the effective quenching of upconverted light from Au/UCNP via FRET after target (ochratoxin A, OTA) detection. The solid-phase, single-step aptasensor showed a linear range of 0.1-1000 ng mL^-1 and limit of detection of 0.022 ng mL^-1 within 30 min toward OTA. Furthermore, reusability of the solid-phase aptasensor was evaluated for three cycles of detection and regeneration, establishing its apparent reusability via heat treatment. Hence, such solid-phase, single-step aptasensors pave the path to the development of a portable and reusable biosensor platform for POC testing.

Clinical efficacy of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in patients with multidrug-resistant bacteremia: a single-center study in Korea

BACKGROUND/AIMS

Matrix-assisted laser desorption/ionization time-of-f light mass spectrometry (MALDI-TOF MS) is a new diagnostic tool for microorganism identification. The clinical usefulness of this approach has not been widely examined in Korea. This retrospective pre-post-intervention quasi-experimental study examined the effect of MALDI-TOF MS on patients with multidrug-resistant (MDR) bacteremia in the intensive care unit (ICU).

METHODS

All consecutive patients with MDR bacteremia in the ICU of a tertiary care hospital between March 2011 and February 2013 and between March 2014 and February 2016 were enrolled. MALDI-TOF MS was introduced between these periods. In the pre-intervention and intervention groups, microorganisms were identified by conventional means and by MALDI-TOF MS, respectively. The groups were compared in terms of time from venipuncture to microorganism identification and antimicrobial susceptibility test results.

RESULTS

In total, 187 patients (mean age, 61.0 years; 56.7% male) were enrolled. Of these, 97 and 90 were in the pre-intervention and intervention groups, respectively. The intervention group had a significantly shorter time from venipuncture to microorganism identification and antimicrobial susceptibility test results (82.5 ± 21.6 hours vs. 92.3 ± 40.4 hours, p = 0.038). The antibiotics were adjusted in 52 patients (26 each in the pre-intervention and intervention groups) based on these results. These groups did not differ in terms of time from venipuncture to antibiotic adjustment, and multivariate regression analysis showed that MALDI-TOF MS-based microorganism identification was not associated with 28-day mortality.

CONCLUSION

Our study showed that MALDI-TOF MS accelerated microorganism identification in patients with MDR bacteremia, but did not inf luence 28-day mortality.

Impact of Cough and Unmet Needs in Chronic Cough: A Survey of Patients in Korea

PURPOSE

Chronic cough is a common problem in various populations. The present study assessed the impact of cough and unmet needs in Korean patients with chronic cough.

METHODS

This cross-sectional multi-center study enrolled adult patients newly referred to clinic for assessment of chronic cough. A second group of patients with unexplained chronic cough following detailed assessment were recruited for comparison. Patients completed self-reported questionnaires, including cough characteristics, impact of cough on daily life, and unmet needs.

RESULTS

A total of 447 subjects were recruited from six referral clinics, including 408 with chronic cough and 39 with unexplained chronic cough. Almost all patients reported that cough impacted their daily lives. Psychosocial impacts were more evident in unexplained cough patients compared to newly referred patients. Approximately 75% of newly referred patients had previously sought medical care for cough on multiple occasions, but the effectiveness of treatment was limited (70.3%) or absent (17.3%). The most frequent unmet need was the ineffectiveness of treatment (49.3%), followed by unclear diagnosis (30.1%). The majority of participants ( > 80%) expressed the need for further information on accessing cough specialists and disease management. The main problem faced by unexplained cough patients was poor cough control despite treatment (64%).

CONCLUSIONS

Chronic cough has a substantial impact on daily life and is worst in those whose cough remains unexplained following assessment. Ineffectiveness of treatment and unclear diagnosis were major unmet needs. Medical information about chronic cough was also lacking. Improvements in the management of chronic cough patients in Korea are necessary.

Clinical outcomes of radial probe endobronchial ultrasound using a guide sheath for diagnosis of peripheral lung lesions in patients with pulmonary emphysema

BACKGROUND

Generally, structural destruction of lung parenchyma, such as pulmonary emphysema, is considered to be related to the low diagnostic yields and high complication rates of lung biopsies of peripheral lung lesions. Currently, little is known about the clinical outcomes of using endobronchial ultrasound with a guide sheath (EBUS-GS) to diagnose peripheral lesions in patients with emphysema.

METHODS

This retrospective study was performed to identify the clinical outcomes of EBUS-GS in patients with pulmonary emphysema. This study included 393 consecutive patients who received EBUS-GS between February 2017 and April 2018. The patients were classified according to the severity of their emphysema, and factors possibly contributing to a successful EBUS-GS procedure were evaluated.

RESULTS

The overall diagnostic yield of EBUS-GS in patients with no or mild emphysema was significantly higher than in those with moderate or severe pulmonary emphysema (78% vs. 61%, P = 0.007). There were no procedure-related complications. The presence of a bronchus sign on CT (P <  0.001) and a "within the lesion" status on EBUS (P = 0.009) were independently associated with a successful EBUS-GS procedure. Although the diagnostic yield of EBUS-GS in patients with moderate-to-severe emphysema was relatively low, a bronchus sign and "within the lesion" status on EBUS were contributing factors for a successful EBUS-GS.

CONCLUSIONS

EBUS-GS is a safe procedure with an acceptable diagnostic yield, even when performed in patients with pulmonary emphysema. The presence of a bronchus sign and "within the lesion" status on EBUS were predictors of a successful procedure.

Factors predicting long-term survival of patients with sepsis on arrival at the emergency department: A single-center, observational study

Predicting long-term outcomes after sepsis is important when caring for patients with this condition. The purpose of the present study was to develop models predicting long-term mortality of patients with sepsis, including septic shock.Retrospective data from 446 patients with sepsis (60.8% men; median age, 71 years) treated at a single university-affiliated tertiary care hospital over 3 years were reviewed. Binary logistic regression was used to identify factors predicting mortality at 180 and 365 days after arrival at the emergency department. Long-term prognosis scores for the 180- and 365-day models were calculated by assigning points to variables according to their β coefficients.The 180- and 365-day mortality rates were 40.6% and 47.8%, respectively. Multivariate analysis identified the following factors for inclusion in the 180- and 365-day models: age ≥65 years, body mass index ≤18.5 kg/m, hemato-oncologic diseases as comorbidities, and ventilator care. Patients with scores of 0 to ≥3 had 180-day survival rates of 83.8%, 70.8%, 42.3%, and 25.0%, respectively, and 365-day survival rates of 72.1%, 64.6%, 36.2%, and 15.9%, respectively (all differences P < .001; log-rank test). The areas under the receiver operating characteristic curves of the 180- and 365-day models were 0.713 (95% confidence interval [CI] 0.668-0.756, P < .001) and 0.697 (95% CI 0.650-0.740, P < .001), respectively.These long-term prognosis models based on baseline patient characteristics and treatments are useful for predicting the 6- and 12-month mortality rates of patients with sepsis.

Patterns of sensitization to aeroallergens and their effect on airway hyper-responsiveness in Busan, Korea

BACKGROUND

Allergen sensitization and its influence on allergic disease can vary depending on ethnicity and geography.

OBJECTIVE

To investigate aeroallergen sensitization patterns and their effect on airway hyper-responsiveness (AHR) in Busan, Korea.

METHODS

We reviewed data for subjects who attended for evaluation of respiratory symptoms between 2011 and 2016. The skin test results of 16 allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, dog, Alternaria, Aspergillus fumigatus, early blossoming tree pollen mix, late blossoming tree pollen mix, alder, birch, oak, grass mix, mugwort, ragweed, and Japanese hop) were analyzed. Age was categorized as group I (15 to < 65 years) or group II (≥ 65 years).

RESULTS

A total of 2,791 subjects were analyzed (mean age: 50.9 years, female 61.3%). AHR was demonstrated in 15.8%; sputum eosinophilia in 12.1%; and atopy in 31.2%. The most commonly sensitizing allergen was house dust mite (17.4% to D. pteronyssinus and 17.9% to D. farinae), followed by late blossoming tree pollen mix (8.8%) and early blossoming tree pollen mix (8.6%). AHR was associated with sensitization to D. pteronyssinus, D. farina, Alternaria, dog, cat, alder, birch, oak, and mugwort. However, group II did not show any associations between AHR and any of the aeroallergens except D. farina. Multiple logistic regression analyses showed that the independent factors for AHR were ever-smoker status, D. farina, and oak sensitization.

CONCLUSIONS

Sensitization to house dust mites and tree pollen was found to be common in Busan. These aeroallergens significantly affected AHR, particularly in the younger group.

Environmental triggers for chronic cough

Cough is a physiological defense reflex for protecting the airways from aspiration and irritation. Thus, roles of environmental triggers are postulated in the pathogenesis of chronic cough. There are several lines of epidemiological evidence demonstrating the relationships between environmental irritant and pollutant exposure and chronic cough. However, positive findings from cross-sectional studies just reflect the protective nature of cough but may not properly address the true impact of environmental triggers. If harmful inhalation is repeated, cough may be seen as chronic but indeed is protective in nature. Therefore, long-term residual outcomes would be the key for understanding the effects of environmental triggers on chronic cough. The present review aims to summarize the associations between chronic cough and environmental pollutants or irritant exposure, with a focus on the long-term residual effects of (1) chronic persistent exposure and (2) acute high-intensity exposure on chronic cough, and also to examine (3) whether childhood irritant/pollutant exposure may increase the risk of chronic cough in adulthood.

Chronic cough in the elderly

Chronic cough is a multi-factorial syndrome commonly presenting as cough hypersensitivity in adult patients. It is a common medical condition in the communities but is more prevalent in older adults. Elderly patients (≥65 years) frequently suffer from multiple comorbidities, which may lead to more clinical heterogeneity in chronic cough and pose diagnostic and therapeutic challenges. Hyposensitivity in cough reflex, probably resulting from central nervous system illnesses, is another potential concern. Despite these complexities and challenges, elderly-specific issues have rarely been addressed in current clinical practice guidelines for chronic cough. Considering recent trends in global population aging, the burden of elderly chronic cough is expected to increase into the near future. This review aimed to respond to following clinical questions: (1) is chronic cough a more heterogeneous condition in the elderly compared to younger adults; and (2) are there additional considerations when choosing the diagnostic and therapeutic approaches to this condition in the elderly?

Adenosine Triphosphate Bioluminescence-Based Bacteria Detection Using Targeted Photothermal Lysis by Gold Nanorods

Bacterial infections are common causes of morbidity and mortality worldwide; therefore, environmental contamination by bacterial pathogens represents a global public health concern. Consequently, a selective, rapid, sensitive, and in-field detection platform for detecting significant bacterial contamination is required to ensure hygiene and protect public health. Here, we developed a fast and simple platform for the selective and sensitive detection of bacteria by measuring adenosine triphosphate (ATP) bioluminescence following targeted photothermal lysis mediated by antibody-conjugated gold nanorods. This method employed both targeted photothermal lysis of bacteria by near-infrared (NIR) irradiation and highly selective detection of the lysed bacteria via ATP bioluminescence within 36 min (incubation, 30 min; NIR irradiation, 6 min). The use of the proposed method allowed limits of detection in pure solution of 12.7, 70.7, and 5.9 CFU for Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes, respectively. Additionally, bacteria were successfully detected on artificially inoculated plastic cutting boards. Furthermore, this method was highly specific, without cross-reaction among pathogenic bacteria. We believe that the proposed method has significant potential as an on-site diagnostic tool for applications associated with public health and environmental pollution monitoring.

Clinical characteristics of exogenous progestogen hypersensitivity

BACKGROUND

Autoimmune progesterone dermatitis is a rare disease characterized by eruption recurrence in the luteal phase of each menstrual cycle. As synthetic progesterones are increasingly used for assisted reproductive techniques (ARTs) for infertility or prevention of abortion, cases of dermatitis caused by exogenous progesterone have been reported.

OBJECTIVE

To investigate the clinical characteristics of exogenous progestogen hypersensitivity (PH).

METHODS

We retrospectively reviewed data from patients presenting with dermatitis induced by exogenous progesterone between 2011 and 2016.

RESULTS

Nine patients had exogenous PH. Six patients were treated with progesterone for threatened abortion, and three for ARTs. Their mean age was 33.6 years, and their mean body mass index was 26.3 kg/m2. They had never experienced an adverse drug reaction. The mean latency to symptom onset was 5.8 days (range 1 h to 11 days). The patients complained of hives, erythema and itching, and one developed anaphylaxis. All patients were treated with antihistamines, and six patients were treated with systemic corticosteroids. Epinephrine was administered to one patient with hypotension. The symptom duration was 1-14 days. Skin tests were performed in four patients; all were positive. Two patients were treated successfully by progesterone desensitization.

CONCLUSIONS

The clinical features of exogenous PH were similar to those of type I hypersensitivity reactions, but tended to develop later and did not respond to antihistamines or steroids. As use of progesterone increases, an understanding of the clinical features of exogenous PH becomes ever-more important.

Combined vitamin C, hydrocortisone, and thiamine therapy for patients with severe pneumonia who were admitted to the intensive care unit: Propensity score-based analysis of a before-after cohort study

PURPOSE

To evaluate the efficacy of combined vitamin C, hydrocortisone, and thiamine in patients with severe pneumonia.

MATERIALS AND METHODS

All consecutive patients with severe pneumonia who were treated with the vitamin C protocol (6 g of vitamin C per day) in June 2017-January 2018 (n = 53) were compared to all consecutive patients with severe pneumonia who were treated in June 2016-January 2017 (n = 46). Propensity score analysis was used to adjust for potential baseline differences between the groups.

RESULTS

In the propensity-matched cohort (n = 36/group), the treated patients had significantly less hospital mortality than the control group (17% vs. 39%; P = 0.04). The vitamin C protocol associated independently with decreased mortality in propensity score-adjusted analysis (adjusted odds ratio = 0.15, 95% confidence interval = 0.04-0.56, P = 0.005). Relative to the control group, the treatment group had a significantly higher median improvement in the radiologic score at day 7 compared with baseline (4 vs. 2; P = 0.045). The vitamin C protocol did not increase the rates of acute kidney injury or superinfection.

CONCLUSIONS

Combined vitamin C, hydrocortisone, and thiamine therapy may benefit patients with severe pneumonia.

A Randomized, Multicenter, Double-blind, Phase III Study to Evaluate the Efficacy on Allergic Rhinitis and Safety of a Combination Therapy of Montelukast and Levocetirizine in Patients With Asthma and Allergic Rhinitis

PURPOSE

The aim of this study was to evaluate the efficacy and safety of a fixed-dose combination of montelukast and levocetirizine in patients with perennial allergic rhinitis with mild to moderate asthma compared with the efficacy and safety of montelukast alone.

METHODS

This study was a 4-week, randomized, multicenter, double-blind, Phase III trial. After a 1-week placebo run-in period, the subjects were randomized to receive montelukast (10 mg/day, n = 112) or montelukast (10 mg/day)/levocetirizine (5 mg/day) (n = 116) treatment for 4 weeks. The primary efficacy end point was mean daytime nasal symptom score. Other efficacy end points included mean nighttime nasal symptom score, mean composite symptom score, overall assessment of allergic rhinitis by both subjects and physicians, forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), FEV₁/FVC, asthma control test score, and the frequency of rescue medication used during the treatment period.

FINDINGS

Of 333 patients screened for this study, 228 eligible patients were randomized to treatment. The mean (SD) age of patients was 43.32 (15.02) years, and two thirds of subjects were female (66.67%). The demographic characteristics were similar between the treatment groups. Compared with the montelukast group, the montelukast/levocetirizine group reported significant reductions in mean daytime nasal symptom score (least squares mean [SE] of combination vs montelukast, -0.98 [0.06] vs -0.81 [0.06]; P = 0.045). For all other allergic rhinitis efficacy end points, the montelukast/levocetirizine group showed greater improvement than the montelukast group. Similar results were observed in overall assessment scores and in FEV₁, FVC, FEV₁/FVC, and asthma control test score changes from baseline for the 2 treatment groups. Montelukast/levocetirizine was well tolerated, and the safety profile was similar to that observed in the montelukast group.

IMPLICATIONS

The fixed-dose combination of montelukast and levocetirizine was effective and safe in treating perennial allergic rhinitis in patients with asthma compared with montelukast alone. ClinicalTrials.gov identifier: NCT02552667.

Ultrasensitive Detection of Escherichia coli O157:H7 by Immunomagnetic Separation and Selective Filtration with Nitroblue Tetrazolium/5-Bromo-4-chloro-3-indolyl Phosphate Signal Amplification

Here, we report an enhanced colorimetric method using enzymatic amplification with nitroblue tetrazolium (NBT)/5-bromo-4-chloro-3-indolyl phosphate (BCIP) precipitation for the ultrasensitive detection of Escherichia coli O157:H7 through immunomagnetic separation-selective filtration. Biotinylated anti- E. coli O157:H7 antibody and streptavidin-alkaline phosphatase were conjugated to the surface of magnetic nanoparticles, and E. coli O157:H7-conjugates complexes remained on the membrane filter surface. The resultant light brown spots on the membrane filter were amplified with NBT/BCIP solution to yield enzyme-catalyzed precipitation, which increased with an increasing E. coli O157:H7 concentration. E. coli O157:H7 was detected in pure samples with limits of detection of 10 and 6.998 colony-forming units (CFU)/mL through visual observation and measurement of optical density, respectively. The proposed method was applied to a lettuce sample inoculated with selective E. coli O157:H7, which was detected within 55 min without cross-reactivity to non-target bacteria. This enhanced colorimetric method has potential for on-site detection of food contaminants and environmental pollutants.

Distinct mechanisms for the upconversion of NaYF4:Yb3+,Er3+ nanoparticles revealed by stimulated emission depletion

Upconversion nanoparticles (UCNPs) have attracted enormous interest over the past few years because of their unique optical properties and potential for use in various applications such as bioimaging probes, biosensors, and light-harvesting materials for photovoltaics. The improvement of imaging resolution is one of the most important goals for UCNPs used in biological applications. Super-resolution imaging techniques that overcome the fundamental diffraction limit of light rely on the photochemistry of organic dyes or fluorescent proteins. Here we report our progress toward super-resolution microscopy with UCNPs. We found that the red emission (655 nm) of core/shell UCNPs with the structure NaYF₄:Yb³⁺,Er³⁺/NaYF₄ could be modulated by emission depletion (ED) of the intermediate state that interacts resonantly with an infrared beam (1540 nm). In contrast, the green emission bands (525 and 545 nm) of the UCNPs were less affected by irradiation with the infrared beam. The origin of such distinct behaviors between the green and red emissions was attributed to their different photophysical pathways.

Household tuberculosis contact investigation in a tuberculosis-prevalent country: Are the tuberculin skin test and interferon-gamma release assay enough in elderly contacts?

The high background rates of positive results on the tuberculin skin test (TST) and interferon-gamma release assay (IGRA) sometimes confuse the investigation of tuberculosis (TB) contact in TB-prevalent countries, particularly in elderly contacts. The aim was to investigate the predictive value of TST and IGRA for diagnosing latent TB infection (LTBI) in elderly household contacts in South Korea.In this retrospective study, TST and IGRA results of household contacts of suspected pulmonary TB patients were reviewed according to the index patient's final diagnosis (TB group: culture-confirmed pulmonary TB, non-TB group: pulmonary disease other than TB).A total of 249 contacts were included in the analysis (188 in the TB group and 61 in the non-TB group). In the TB group, TST and IGRA were positive in 42.6% and 45.7% of contacts, respectively. In the non-TB group, TST and IGRA were positive in 32.8% and 23.0% of contacts, respectively. TST did not show any differences between the TB and non-TB groups for any age group, whereas IGRA showed differences between the 2 groups for those ages 18 to 39 and 40 to 59 years. However, there were no significant differences between the groups for the ≥60 years old group.In elderly contacts, neither TST nor IGRA showed clear discrimination of positivity between the groups. Further studies are needed to predict which elderly contacts are at risk for progression to active TB as well as to accurately detect recent Mycobacterium tuberculosis infection in this vulnerable population.

Single-Step LRET Aptasensor for Rapid Mycotoxin Detection

Contamination of foods by mycotoxins is a common yet serious problem. Owing to the increase in consumption of fresh produce, consumers have become aware of food safety issues caused by mycotoxins. Therefore, rapid and sensitive mycotoxin detection is in great demand in fields such as food safety and public health. Here we report a single-step luminescence resonance energy transfer (LRET) aptasensor for mycotoxin detection. To accomplish the single-step sensor, our sensor was constructed by linking a quencher-labeled aptamer through a linker to the surface of upconversion nanoparticles (UCNPs). Our LRET aptasensor is composed of Mn²⁺-doped NaYF₄:Yb³⁺,Er³⁺ UCNPs as the LRET donor, and black hole quencher 3 (BHQ3) as the acceptor. The maximum quenching efficiency is obtained by modulating the linker length, which controls the distance between the quencher and the UCNPs. Our distinctive design of LRET aptasensor allows detection of mycotoxins selectively in colored food samples within 10 min without multiple bioassay steps. We believe our single-step aptasensor has a significant potential for on-site detection of food contaminants, environmental pollutants, and biological metabolites.

Validation of the Prognosis for Prolonged Ventilation (ProVent) score in patients receiving 14days of mechanical ventilation

PURPOSE

To evaluate the performance of the Prognosis for Prolonged Ventilation (ProVent) 14 score in patients requiring prolonged mechanical ventilation (PMV).

MATERIALS AND METHODS

Data were obtained from 366 patients receiving at least 14days of MV between January 2011 and December 2015 at a university-affiliated tertiary care hospital in Korea. ProVent 14 scores were assessed using the six standard variables. Model discrimination was assessed with the area under the receiver operating characteristic curve. Kaplan-Meier estimates were stratified according to the ProVent 14 score to predict 1-year survival.

RESULTS

The median age of the study group was 62years (range, 50-72years); 65% were male, and medical patients comprised 66% of the group. Overall mortality at 1year was 43%. For ProVent 14 scores ranging from 0 to ≥4, 1-year mortality rates were 7%, 22%, 41%, 52%, and 75%, respectively (log-rank test, P<0.001). The area under the receiver operating characteristic curve of the ProVent 14 score predicting 1-year mortality was 0.74 (95% confidence interval, 0.69-0.78).

CONCLUSIONS

The ProVent 14 score accurately identified patients receiving PMV with a high 1-year mortality risk. Further validation in a larger sample is required.

Pleurodesis Using Mistletoe Extract Delivered via a Spray Catheter during Semirigid Pleuroscopy for Managing Symptomatic Malignant Pleural Effusion

BACKGROUND

Talc poudrage during thoracoscopy is considered the standard procedure for patients with symptomatic malignant pleural effusion (MPE). Until now, no alternative technique other than talc poudrage for pleurodesis during medical thoracoscopy has been proposed. Liquid sclerosants, such as mistletoe extract, have been sprayed evenly into the pleural cavity during semirigid pleuroscopy for chemical pleurodesis.

OBJECTIVE

We conducted a retrospective study using the database of semirigid pleuroscopy to identify the usefulness of pleurodesis using a mistletoe extract delivered via a spray catheter during semirigid pleuroscopy for symptomatic MPE.

METHODS

All consecutive patients with symptomatic MPE who underwent semirigid pleuroscopy from October 2015 to September 2016 were registered. The responses were evaluated using chest X- ray or computed tomography 4 weeks after pleurodesis.

RESULTS

The study included 43 patients who underwent pleurodesis with mistletoe extract via a spray catheter during semirigid pleuroscopy. Complete and partial responses were seen in 21 (49%) and 19 (44%) patients, respectively. The median duration of chest tube placement after pleurod-esis was 7 days (range 6-8 days) in the 40 patients with complete or partial responses. No cases of severe hemorrhage, empyema formation, respiratory failure, or procedure-related mortality were observed in the subjects at 4 weeks after semirigid pleuroscopy.

CONCLUSION

Pleurodesis with mistletoe extract delivered via a spray catheter during semirigid pleuroscopy is a safe and effective procedure for managing symptomatic MPE.

Asymmetric Nanocrescent Antenna on Upconversion Nanocrystal

Frequency upconversion activated with lanthanide has attracted attention in various real-world applications, because it is far simpler and more efficient than traditional nonlinear susceptibility-based frequency upconversion, such as second harmonic generation. However, the quantum yield of frequency upconversion of lanthanide-based upconversion nanocrystals remains inefficient for practical applications, and spatial control of upconverted emission is not yet developed. Here, we developed an asymmetric nanocrescent antenna on upconversion nanocrystal (ANAU) to deliver excitation light effectively to the core of upconversion nanocrystal by nanofocusing light and generating asymmetric frequency upconverted emission concentrated toward the tip region. ANAUs were fabricated by high-angle deposition (60°) of gold (Au) on the isolated upconversion nanoparticles supported by nanopillars then moved to refractive-index matched substrate for orientation-dependent upconversion luminescence analysis in the single-nanoparticle scale. We studied shape-dependent nanofocusing efficiency of nanocrescent antennae as a function of the tip-to-tip distance by modulating the deposition angle. The generation of asymmetric frequency upconverted emission toward the tip region was simulated by the asymmetric far-field radiation pattern of dipoles in the nanocrescent antenna and experimentally demonstrated by the orientation-dependent photon intensity of frequency upconverted emission of an ANAU. This finding provides a new way to improve frequency upconversion using an antenna, which locally increases the excitation light and generates the radiation power to certain directions for various applications.

Homogeneous and selective detection of cadmium ions by forming fluorescent cadmium-protein nanoclusters

We synthesized fluorescent Cd nanoclusters (CdNCs) through a protein-directed method, and the synthesis method was utilized for a homogeneous, ultrasensitive, and selective detection of cadmium ion (Cd²⁺). CdNCs were synthesized using a modified protein-directed method for developing a rapid Cd²⁺ detection system. For rapid Cd²⁺ detection, the reaction time was reduced by optimizing the reaction conditions such as temperature, reducing agent concentration, and protein concentration. The synthesized CdNCs had ca. 2 nm diameter and showed strong fluorescence at 485 nm under 365 nm UV light. The fluorescence of the CdNCs increased with increasing Cd²⁺ concentrations, and the limit of detection in deionized water was 15.68 fM. This method enables the detection of Cd²⁺ through the Cd concentration-dependent formation of fluorescent CdNCs in tap, fountain, and pond water samples with detection limits of 0.75, 7.65, and 48.2 fM, respectively. The sensitivity and specificity of our method are comparable to those of several existing methods for Cd²⁺ detection. Furthermore, the system enables the homogeneous detection of Cd²⁺ without separation and washing, thereby broadening its application in analytical chemistry.

Point prevalence and epidemiological characteristics of chronic cough in the general adult population: The Korean National Health and Nutrition Examination Survey 2010-2012

Cough is frequently self-limiting, but may persist longer in certain individuals. Most of previous studies on the epidemiology of chronic cough have only measured period prevalence, and thus have afforded limited information on the burden and natural course. We aimed to investigate the epidemiology of chronic cough by using a point prevalence measure in a large-scale general population.We analyzed cross-sectional data collected from 18,071 adults who participated in the Korean National Health and Nutrition Examination Survey 2010-2012. Presence and duration of current cough was ascertained by structured questionnaires, and cough was classified into acute (<3 weeks), subacute (3-8 weeks), or chronic cough (≥8 weeks). Demographic and clinical parameters were examined in relation to chronic cough.The point prevalences of acute, subacute, and chronic cough were 2.5 ± 0.2%, 0.8 ± 0.1% and 2.6 ± 0.2%, respectively. The proportion of current cough showed a steep decrease after 1 week of duration. However, 2 peaks in the prevalence of current cough were revealed; cough durations of less than 1 week and longer than 1 year were most common (31.1% and 27.7% of current cough, respectively). Subacute and chronic cough were more prevalent in the elderly (≥65 years); the positive associations with older age were independent of other confounders, including current smoking and comorbidities.This is the first report on the epidemiology of cough using a point prevalence measure in a nationally representative population sample. Our findings indicate a high burden of chronic cough among adults with current cough in the community. The dual-peak of cough duration suggested that the pathophysiology of acute and chronic cough may differ. The preponderance of elderly people in the prevalence of chronic cough warrants further investigation. In addition, more sophistication and validation of tools to define chronic cough will help our understanding of the epidemiology.