Next-generation balloon-expandable Myval transcatheter heart valve in low-risk aortic stenosis patients.

OBJECTIVES: We aimed to describe hemodynamic performance and clinical outcomes at 30-day follow-up of the balloon-expandable (BE) Myval transcatheter heart valve (THV) in low-risk patients. BACKGROUND: The results of the next-generation BE Myval THV in low-risk aortic stenosis (AS) patients are still unknown. METHODS: Retrospective registry performed in nine European centers including patients with low predicted operative mortality risk according to Society of thoracic surgeons (STS) and European system for cardiac operative risk evaluation (EuroSCORE-II) scores. RESULTS: Between September 2019 and February 2021, a total of 100 patients (51% males, mean age 80 ± 6.5 years) were included. Mean STS score and EuroSCORE-II were 2.4 ± 0.8% and 2.2 ± 0.7%, respectively. Intermediate sizes were used in 39% (21.5 mm: 8%, 24.5 mm: 15%, 27.5 mm: 15%). There were no cases of valve embolization, coronary artery occlusion, annulus rupture, or procedural death. A definitive pacemaker implantation was needed in eight patients (8%). At 30-day follow-up aortic valve area (0.7 ± 0.2 vs. 2.1 ± 0.6 cm2 ) and mean aortic valve gradient (43.4 ± 11.1 vs. 9.0 ± 3.7 mmHg) improved significantly (p < 0.001). Moderate aortic regurgitation occurred in 4%. Endpoints of early safety and clinical efficacy were 3 and 1%, respectively. CONCLUSIONS: Hemodynamic performance and 30-day clinical outcomes of the BE Myval THV in low-risk AS patients were favorable. Longer-term follow-up is warranted.

Temporal Trends, Characteristics, and Outcomes of Infective Endocarditis After Transcatheter Aortic Valve Replacement.

BACKGROUND: Procedural improvements combined with the contemporary clinical profile of patients undergoing transcatheter aortic valve replacement (TAVR) may have influenced the incidence and outcomes of infective endocarditis (IE) following TAVR. We aimed to determine the temporal trends, characteristics, and outcomes of IE post-TAVR. METHODS: Observational study including 552 patients presenting definite IE post-TAVR. Patients were divided in 2 groups according to the timing of TAVR (historical cohort [HC]: before 2014; contemporary cohort [CC]: after 2014). RESULTS: Overall incidence rates of IE were similar in both cohorts (CC vs HC: 5.45 vs 6.52 per 1000 person-years; P = .12), but the rate of early IE was lower in the CC (2.29‰ vs 4.89‰, P < .001). Enterococci were the most frequent microorganism. Most patients presented complicated IE ( CC: 67.7%; HC: 69.6%; P = .66), but the rate of surgical treatment remained low (CC: 20.7%; HC: 17.3%; P = .32). The CC exhibited lower rates of in-hospital acute kidney injury (35.1% vs 44.6%; P = .036) and in-hospital (26.6% vs 36.4%; P = .016) and 1-year (37.8% vs 53.5%; P < .001) mortality. Higher logistic EuroScore, Staphylococcus aureus etiology, and complications (stroke, heart failure, and acute renal failure) were associated with in-hospital mortality in multivariable analyses (P < .05 for all). CONCLUSIONS: Although overall IE incidence has remained stable, the incidence of early IE has declined in recent years. The microorganism, high rate of complications, and very low rate of surgical treatment remained similar. In-hospital and 1-year mortality rates were high but progressively decreased over time.

Crystallization-based upcycling of iron oxyhydroxide for efficient arsenic capture in contaminated soils.

Arsenic (As)-contaminated soil inevitably exists in nature and has become a global challenge for a sustainable future. Current processes for As capture using natural and structurally engineered nanomaterials are neither scientifically nor economically viable. Here, we established a feasible strategy to enhance As-capture efficiency and ecosystem health by structurally reorganizing iron oxyhydroxide, a natural As stabilizer. We propose crystallization to reorganize FeOOH-acetate nanoplatelets (r-FAN), which is universal for either scalable chemical synthesis or reproduction from natural iron oxyhydroxide phases. The r-FAN with wide interlayer spacing immobilizes As species through a synergistic mechanism of electrostatic intercalation and surface chemisorption. The r-FAN rehabilitates the ecological fitness of As-contaminated artificial and mine soils, as manifested by the integrated bioassay results of collembolan and plants. Our findings will serve as a cornerstone for crystallization-based material engineering for sustainable environmental applications and for understanding the interactions between soil, nanoparticles, and contaminants.

Latest-iteration balloon- and self-expandable transcatheter valves for severe bicuspid aortic stenosis: the TRITON study.

INTRODUCTION AND OBJECTIVES: No comparisons have been published yet regarding the newest iteration of balloon- and self-expandable transcatheter heart valves for the treatment of bicuspid aortic valve (BAV) stenosis. METHODS: Multicenter registry of consecutive patients with severe BAV stenosis treated with balloon-expandable transcatheter heart valves (Myval and SAPIEN 3 Ultra, S3U) or self-expanding Evolut PRO+(EP+). TriMatch analysis was carried out to minimize the impact of baseline differences. The primary endpoint of the study was 30-day device success, and the secondary endpoints were the composite and individual components of early safety at 30 days. RESULTS: A total of 360 patients (age 76.6±7.6 years, 71.9% males) were included: 122 Myval (33.9%), 129 S3U (35.8%), and 109 EP+(30.3%). The mean STS score was 3.6±1.9%. There were no cases of coronary artery occlusion, annulus rupture, aortic dissection, or procedural death. The primary endpoint of device success at 30 days was significantly higher in the Myval group (Myval: 100%; S3U: 87.5%; and EP+: 81.3%), mainly due to higher residual aortic gradients with S3U and greater≥moderate aortic regurgitation (AR) with EP+. No significant differences were found in the unadjusted rate of pacemaker implantation. CONCLUSIONS: In patients with BAV stenosis deemed unsuitable for surgery, Myval, S3U and EP+showed similar safety but balloon-expandable Myval had better gradients than S3U, and both balloon-expandable devices had lower residual AR than EP+, suggesting that, taking into consideration the patient-specific risks, any of these devices can be selected with optimal outcomes.

Infective Endocarditis Caused by Staphylococcus aureus After Transcatheter Aortic Valve Replacement.

BACKGROUND: Staphylococcus aureus (SA) has been extensively studied as causative microorganism of surgical prosthetic-valve infective endocarditis (IE). However, scarce evidence exists on SA IE after transcatheter aortic valve replacement (TAVR). METHODS: Data were obtained from the Infectious Endocarditis After TAVR International Registry, including patients with definite IE after TAVR from 59 centres in 11 countries. Patients were divided into 2 groups according to microbiologic etiology: non-SA IE vs SA IE. RESULTS: SA IE was identified in 141 patients out of 573 (24.6%), methicillin-sensitive SA in most cases (115/141, 81.6%). Self-expanding valves were more common than balloon-expandable valves in patients presenting with early SA IE. Major bleeding and sepsis complicating TAVR, neurologic symptoms or systemic embolism at admission, and IE with cardiac device involvement (other than the TAVR prosthesis) were associated with SA IE (P < 0.05 for all). Among patients with IE after TAVR, the likelihood of SA IE increased from 19% in the absence of those risk factors to 84.6% if ≥ 3 risk factors were present. In-hospital (47.8% vs 26.9%; P < 0.001) and 2-year (71.5% vs 49.6%; P < 0.001) mortality rates were higher among patients with SA IE vs non-SA IE. Surgery at the time of index SA IE episode was associated with lower mortality at follow-up compared with medical therapy alone (adjusted hazard ratio 0.46, 95% CI 0.22-0.96; P = 0.038). CONCLUSIONS: SA IE represented approximately 25% of IE cases after TAVR and was associated with very high in-hospital and late mortality. The presence of some features determined a higher likelihood of SA IE and could help to orientate early antibiotic regimen selection. Surgery at index SA IE was associated with improved outcomes, and its role should be evaluated in future studies.

Stroke Complicating Infective Endocarditis After Transcatheter Aortic Valve Replacement.

BACKGROUND: Stroke is one of the most common and potentially disabling complications of infective endocarditis (IE). However, scarce data exist about stroke complicating IE after transcatheter aortic valve replacement (TAVR). OBJECTIVES: The purpose of this study was to determine the incidence, risk factors, clinical characteristics, management, and outcomes of patients with definite IE after TAVR complicated by stroke during index IE hospitalization. METHODS: Data from the Infectious Endocarditis after TAVR International Registry (including 569 patients who developed definite IE following TAVR from 59 centers in 11 countries) was analyzed. Patients were divided into two groups according to stroke occurrence during IE admission (stroke [S-IE] vs. no stroke [NS-IE]). RESULTS: A total of 57 (10%) patients had a stroke during IE hospitalization, with no differences in causative microorganism between groups. S-IE patients exhibited higher rates of acute renal failure, systemic embolization, and persistent bacteremia (p < 0.05 for all). Previous stroke before IE, residual aortic regurgitation ≥moderate after TAVR, balloon-expandable valves, IE within 30 days after TAVR, and vegetation size >8 mm were associated with a higher risk of stroke during the index IE hospitalization (p < 0.05 for all). Stroke rate in patients with no risk factors was 3.1% and increased up to 60% in the presence of >3 risk factors. S-IE patients had higher rates of in-hospital mortality (54.4% vs. 28.7%; p < 0.001) and overall mortality at 1 year (66.3% vs. 45.6%; p < 0.001). Surgical treatment was not associated with improved outcomes in S-IE patients (in-hospital mortality: 46.2% in surgical vs. 58.1% in no surgical treatment; p = 0.47). CONCLUSIONS: Stroke occurred in 1 of 10 patients with IE post-TAVR. A history of stroke, short time between TAVR and IE, vegetation size, valve prosthesis type, and residual aortic regurgitation determined an increased risk. The occurrence of stroke was associated with increased in-hospital and 1-year mortality rates, and surgical treatment failed to improve clinical outcomes.

Simultaneous real-time assay of copper and cadmium ions by infrared photo diode electrode implanted in the muscle of live fish.

The electrical circuit of an infrared photodiode electrode (IPE) was used in the simultaneous assay of copper and cadmium ions. The electrode's cyclic voltammetry (CV), chronoamperometry and square-wave (SW) stripping voltammetric optimum conditions were examined. Results for 0-160 mg L(-1) and 50-400 microg L(-1) SW Cu(II) Cd(II), the relative standard deviation of 0.158 Cu(II), 0.077 Cd(II) (n = 15) using 20.0 mg L(-1) have been obtained at optimum conditions. The low detection limit (S/N) was attained to be at 14.71 microg L(-1)(2.31 x 10(-7) mol L(-1)) Cu(II) and 18.42 microg L(-1)(1.63 x 10(-7) mol L(-1)) Cd(II). The handmade electrode was implanted deep in the muscle of live fish and interfaced with an electrochemical workstation. Real-time analytical application was performed on the online assay of living tissue as the specimen was moving. The methods are deemed useful in interfaced assay for physiological control, nanodiode fabrication, and in the production of laboratory on a biochip.

Extracellular Vesicles Released by Lactobacillus paracasei Mitigate Stress-induced Transcriptional Changes and Depression-like Behavior in Mice

Various probiotic strains have been reported to affect emotional behavior. However, the underlying mechanisms by which specific probiotic strains change brain function are not clearly understood. Here, we report that extracellular vesicles derived from Lactobacillus paracasei (Lpc-EV) have an ability to produce genome-wide changes against glucocorticoid (GC)-induced transcriptional responses in HT22 hippocampal neuronal cells. Genome-wide analysis using microarray assay followed by Rank-Rank Hypergeometric Overlap (RRHO) method leads to identify the top 20%-ranked 1,754 genes up- or down-regulated following GC treatment and their altered expressions are reversed by Lpc-EV in HT22 cells. Serial k-means clustering combined with Gene Ontology enrichment analyses indicate that the identified genes can be grouped into multiple functional clusters that contain functional modules of “responses to stress or steroid hormones”, “histone modification”, and “regulating MAPK signaling pathways”. While all the selected genes respond to GC and Lpc-EV at certain levels, the present study focuses on the clusters that contain Mkp-1, Fkbp5, and Mecp2, the genes characterized to respond to GC and Lpc-EV in opposite directions in HT22 cells. A translational study indicates that the expression levels of Mkp-1, Fkbp5, and Mecp2 are changed in the hippocampus of mice exposed to chronic stress in the same directions as those following GC treatment in HT22 cells, whereas Lpc-EV treatment restored stress-induced changes of those factors, and alleviated stress-induced depressive-like behavior. These results suggest that Lpc-EV cargo contains bioactive components that directly induce genome-wide transcriptional responses against GC-induced transcriptional and behavioral changes.

Report on the methacholine bronchial provocation test protocol: An updated statement of Korean Academy of Asthma, Allergy and Clinical Immunology

The Korean Academy of Asthma, Allergy, and Clinical Immunology task force report aims to provide new protocols for methacholine challenge test (MCT). Although new devices have different delivery system compared to old ones, previous protocols are still used, which cannot guarantee adequate diagnoses of asthma. Another important issue is the recent recommendation in European Respiratory Society (ERS) technical standard guideline to use a delivered methacholine dose that causes a 20% decrease in forced expiratory volume in 1 second (FEV1) (PD 20). Although the previous protocol based on the methacholine concentration causing a 20% decrease in FEV1 (PC 20) has been used globally, several studies have reported that PD 20 is more reliable and applicable for new protocols of MCT. Indeed, a tidal breathing inhalation protocol using a breath-actuated or continuous nebulizer is recommended. Herein, we recommend 3 protocols for the MCT using new devices and provide a brief summary of the change in strategy based on the updated ERS guideline.

N-Acetylcysteine Induces Apoptotic, Oxidative and Excitotoxic Neuronal Death in Mouse Cortical Cultures / 전남의대학술지

N-acetylcysteine (NAC) has been used as an antioxidant to prevent oxidative cell death.However, we found NAC itself to induce neuronal death in mouse cortical cultures.Therefore, the current study was performed to investigate the mechanism of neuronal death caused by NAC. Cell death was assessed by measuring lactate dehydrogenase efflux to bathing media after 24-48 h exposure to NAC. NAC (0.1-10 mM) induced neuronal death in a concentration- and exposure time-dependent manner. However, NAC did not injure astrocytes even at a concentration of 10 mM. Also, 10 mM NAC markedly attenuated oxidative astrocyte death induced by 0.5 mM diethyl maleate or 0.25 mM H2O2 . The NMDA receptor antagonist MK-801 (10 μM) markedly attenuated the neuronal death caused by 10 mM NAC, while NBQX did not affect the neuronal death. Cycloheximide (a protein synthesis inhibitor, 0.1 μg/mL) and z-VAD-FMK (a caspase inhibitor, 100 μM) also significantly attenuated neuronal death. Apoptotic features such as chromatin condensation, nuclear fragmentation, and caspase 3 activation were observed 1 h after the NAC treatment. The neuronal death induced by 1 or 10 mM NAC was significantly attenuated by the treatment with 100 μM Trolox or 1 mM ascorbic acid. NAC induced the generation of intracellular reactive oxygen species (ROS), as measured by the fluorescent dye 2’,7’-dichlorofluorescein diacetate. The ROS generation was almost completely abolished by treatment with Trolox or ascorbic acid. These findings demonstrate that NAC can cause oxidative, apoptotic, and excitotoxic neuronal death in mouse neuronal cultures.

Extracellular vesicles derived from small intestinal lamina propria reduce antigen-specific immune response

Background/Aims@#Extracellular vesicles (EVs) are secreted from various types of cells and have specific functions related to their origin. EVs are observed in the small intestinal lamina propria (lpEVs), but their function remains unclear. This study aimed to investigate the role of lpEVs. @*Methods@#LpEVs were isolated from antigen (ovalbumin [OVA])-fed mice (lpEVs/OVA), and administrated to the naïve mice for 5 days before induction of lung inflammation. Afterwards, the mice were sensitized and challenged with OVA to evaluate the role of lpEVs/OVA in the regulation of immune tolerance. @*Results@#The isolated lpEVs/OVA were sphere-shaped, bi-layered vesicles of approximately 50 to 100 nm in size. The vesicles expressed CD81, A33 antigen, and major histocompatibility complex (MHC) class II on the surface. When administrated to naïve mice, the lpEVs/OVA migrated to the spleen. Intraperitoneal lpEVs/OVA administration to naïve mice decreased the immune response against sensitized antigen in a CD4+FoxP3+T cell-dependent manner. @*Conclusions@#EVs are actively secreted from small intestinal epithelial cells to deliver information about orally administered antigens to immune cells, which will facilitate the modulation of the immune response by acting as an intercellular communicasome.

Clinical Manifestations and Maternal and Perinatal Outcomes in Pregnancy Following Laboratory-Confirmed SARS-CoV-2 Infection in South Korea

Purpose@#To determine the clinical manifestations and maternal and perinatal outcomes in pregnant women with coronavirus disease 2019 (COVID-19). @*Methods@#We conducted a retrospective observational study of pregnant women with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who were admitted to National Health Insurance Service (NHIS) Ilsan Hospital between August 2020 and October 2021. The maternal and perinatal outcomes were investigated. @*Results@#Among 184 pregnant women infected with SARS-CoV-2, 79 women delivered. Of the women who delivered, with 36 women giving birth during the quarantine period. At delivery, 45 women were positive for SARS-CoV-2 by polymerase chain reaction (PCR), whereas 34 women were negative. The most common clinical manifestations were cough (65.2%), fever (38.0%), and myalgia (33.2%). Regarding perinatal outcomes, none of the babies had an Apgar score <7 at 5 minutes, and none were intubated following the delivery. The preterm birth rate and small-for-gestational-age (SGA) rate were 15.2% and 16.5%, respectively. All babies who was delivered at NHIS Ilsan Hospital were negative for SARS-CoV-2 infection by PCR, which was evaluated using amniotic fluid, cord blood, neonatal nasopharyngeal and oropharyngeal swabs in the 1st and 2nd days following delivery, although 45 women were positive for SARS-CoV-2 infection by PCR at the time of delivery. @*Conclusion@#Most pregnant women with COVID-19 in South Korea were unlikely to manifest symptoms or present with a severe disease progression. The observed preterm birth rate and SGA rate were higher in women with COVID-19 than in those without COVID-19. However, there was no evidence of vertical transmission, and all babies were negative for SARS-CoV-2 infection during pregnancy.

Dysphagia Aortica Initially Misdiagnosed as Poststroke Dysphagia: A Case Report / 대한연하장애학회지

Dysphagia aortica is a rare form of mechanical dysphagia characterized by extrinsic compression of the esophagus by the aorta. A 69-year-old male reported experiencing swallowing difficulties for five months, along with nausea, abdominal discomfort, weight loss, and severe reflux. Considering his age and a medical history of hypertension and stenosis of the cerebral artery, poststroke dysphagia was initially suspected. However, brain magnetic resonance imaging revealed no evidence of acute or subacute stroke. Further evaluation was achieved via enhanced chest computed tomography to locate the focus of the systemic inflammation. A thoracic aortic aneurysm about 8.7×5.0 cm in size, with signs of impending rupture, was observed. This case reinforces that a high possibility for dysphagia aortica should be considered under conditions of unclear etiology of dysphagia but the presence of associated symptoms, such as progressive intolerance to solids and ultimately to liquids, weight loss, and nausea.

Clinical Characteristics of Patients Who Contracted the SARS-CoV-2 Omicron Variant from an Outbreak in a Single Hospital

There are few studies on the severity and prognosis of patients infected with the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) omicron variant. From January 11, 2022 to January 25, 2022, 181 patients were infected with the SARS-CoV-2 omicron variant in a single hospital in Korea. The initial clinical characteristics were investigated through the COVID-19 basic investigation form. Outcomes were reviewed using medical records. The median age of the patients was 57 years (range 1–90), and 95 patients (52.5%) were male. None were re-infected with SARS-CoV-2, and 127 (70.2%) were fully vaccinated (boosted or within 6 months after second vaccination). Forty-two patients (23.2%) were asymptomatic. Among symptomatic patients, the frequency of symptoms was as follows: cough (37.0%), sore throat (33.7%), and fever (30.4%). In terms of disease severity, 168 (92.8%) patients did not require supplemental oxygen, 6 (3.3%) required low-flow oxygen, 5 (2.8%) required high-flow oxygen, and 2 (1.1%) died. Four of the five individuals who required high-flow oxygen and the two who died were not vaccinated. Most of the patients who contracted the SARS-CoV-2 omicron variant exhibited mild clinical features; however, severe clinical features including mortality were encountered among individuals who were not vaccinated.

Advanced Silicon-on-Insulator: Crystalline Silicon on Atomic Layer Deposited Beryllium Oxide.

Silicon-on-insulator (SOI) technology improves the performance of devices by reducing parasitic capacitance. Devices based on SOI or silicon-on-sapphire technology are primarily used in high-performance radio frequency (RF) and radiation sensitive applications as well as for reducing the short channel effects in microelectronic devices. Despite their advantages, the high substrate cost and overheating problems associated with complexities in substrate fabrication as well as the low thermal conductivity of silicon oxide prevent broad applications of this technology. To overcome these challenges, we describe a new approach of using beryllium oxide (BeO). The use of atomic layer deposition (ALD) for producing this material results in lowering the SOI wafer production cost. Furthermore, the use of BeO exhibiting a high thermal conductivity might minimize the self-heating issues. We show that crystalline Si can be grown on ALD BeO and the resultant devices exhibit potential for use in advanced SOI technology applications.

Licochalcone H Induces Cell Cycle Arrest and Apoptosis in Human Skin Cancer Cells by Modulating JAK2/STAT3 Signaling

Licochalcone H (LCH) is a phenolic compound synthetically derived from licochalcone C (LCC) that exerts anticancer activity. In this study, we investigated the anticancer activity of LCH in human skin cancer A375 and A431 cells. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell viability assay was used to evaluate the antiproliferative activity of LCH. Cell cycle distribution and the induction of apoptosis were analyzed by flow cytometry. Western blotting assays were performed to detect the levels of proteins involved in cell cycle progression, apoptosis, and the JAK2/STAT3 signaling pathway. LCH inhibited the growth of cells in dose- and time-dependent manners. The annexin V/propidium iodide double staining assay revealed that LCH induced apoptosis, and the LCH-induced apoptosis was accompanied by cell cycle arrest in the G1 phase. Western blot analysis showed that the phosphorylation of JAK2 and STAT3 was decreased by treatment with LCH. The inhibition of the JAK2/STAT3 signaling pathway by pharmacological inhibitors against JAK2/STAT3 (cryptotanshinone (CTS) and S3I-201) simulated the antiproliferative effect of LCH suggesting that LCH induced apoptosis by modulating JAK2/STAT3 signaling.

Risk Prediction Model Based on Magnetic Resonance Elastography-Assessed Liver Stiffness for Predicting Posthepatectomy Liver Failure in Patients with Hepatocellular Carcinoma

Background/Aims@#Posthepatectomy liver failure (PHLF) is a major complication that increases mortality in patients with hepatocellular carcinoma after surgical resection. The aim of this retrospective study was to evaluate the utility of magnetic resonance elastography-assessed liver stiffness (MRE-LS) for the prediction of PHLF and to develop an MRE-LS-based risk prediction model. @*Methods@#A total of 160 hepatocellular carcinoma patients who underwent surgical resection with available preoperative MRE-LS data were enrolled. Clinical and laboratory parameters were collected from medical records. Logistic regression analyses were conducted to identify the risk factors for PHLF and develop a risk prediction model. @*Results@#PHLF was present in 24 patients (15%). In the multivariate logistic analysis, high MRE-LS (kPa; odds ratio [OR] 1.49, 95% confidence interval [CI] 1.12 to 1.98, p=0.006), low serum albumin (≤3.8 g/dL; OR 15.89, 95% CI 2.41 to 104.82, p=0.004), major hepatic resection (OR 4.16, 95% CI 1.40 to 12.38, p=0.014), higher albumin-bilirubin score (>–0.55; OR 3.72, 95% CI 1.15 to 12.04, p=0.028), and higher serum α-fetoprotein (>100 ng/mL; OR 3.53, 95% CI 1.20 to 10.40, p=0.022) were identified as independent risk factors for PHLF. A risk prediction model for PHLF was established using the multivariate logistic regression equation. The area under the receiver operating characteristic curve (AUC) of the risk prediction model was 0.877 for predicting PHLF and 0.923 for predicting grade B and C PHLF. In leave-one-out cross-validation, the risk model showed good performance, with AUCs of 0.807 for all-grade PHLF and 0. 871 for grade B and C PHLF. @*Conclusions@#Our novel MRE-LS-based risk model had excellent performance in predicting PHLF, especially grade B and C PHLF.

A Multicenter Study to Identify the Respiratory Pathogens Associated with Exacerbation of Chronic Obstructive Pulmonary Disease in Korea / 결핵및호흡기질환

Background@#Although respiratory tract infection is one of the most important factors triggering acute exacerbation of chronic obstructive pulmonary disease (AE-COPD), limited data are available to suggest an epidemiologic pattern of microbiology in South Korea. @*Methods@#A multicenter observational study was conducted between January 2015 and December 2018 across 28 hospitals in South Korea. Adult patients with moderate-to-severe acute exacerbations of COPD were eligible to participate in the present study. The participants underwent all conventional tests to identify etiology of microbial pathogenesis. The primary outcome was the percentage of different microbiological pathogens causing AE-COPD. A comparative microbiological analysis of the patients with overlapping asthma–COPD (ACO) and pure COPD was performed. @*Results@#We included 1,186 patients with AE-COPD. Patients with pure COPD constituted 87.9% and those with ACO accounted for 12.1%. Nearly half of the patients used an inhaled corticosteroid-containing regimen and one-fifth used systemic corticosteroids. Respiratory pathogens were found in 55.3% of all such patients. Bacteria and viruses were detected in 33% and 33.2%, respectively. Bacterial and viral coinfections were found in 10.9%. The most frequently detected bacteria were Pseudomonas aeruginosa (9.8%), and the most frequently detected virus was influenza A (10.4%). Multiple bacterial infections were more likely to appear in ACO than in pure COPD (8.3% vs. 3.6%, p=0.016). @*Conclusion@#Distinct microbiological patterns were identified in patients with moderate-to-severe AE-COPD in South Korea. These findings may improve evidence-based management of patients with AE-COPD and represent the basis for further studies investigating infectious pathogens in patients with COPD.

Continued Upward Trend in Non-Tuberculous Mycobacteria Isolation over 13 Years in a Tertiary Care Hospital in Korea

Purpose@#Despite decreased prevalence of tuberculosis, the incidence of the diseases associated with nontuberculous mycobacteria (NTM) has been increasing in South Korea and around the world. The present retrospective study was conducted to determine longitudinal changes in the epidemiology and distribution of NTM over 13 years at a tertiary care hospital in Korea. @*Materials and Methods@#We retrospectively analyzed data on Mycobacterium species over 13 years (January 2007 to December 2019) by utilizing the laboratory information system. Mycobacterium species were identified using biochemical tests and PCR-restriction fragment length polymorphism and Mycobacteria GenoBlot assays. @*Results@#After excluding duplicates from the initial pool of 17996 mycobacterial isolates, 7674 strains were analyzed and 2984 (38.9%) NTM were isolated. The proportion of NTM continuously increased over the 13-year period, from 17.0% in 2007 to 57.5% in 2019. Among the NTM isolates, the most common species were Mycobacterium intracellulare (50.6%), M. avium (18.3%), M. fortuitum complex (4.9%), M. abscessus (4.5%), M. gordonae (3.3%), M. kansasii (1.1%), M. chelonae (1.0%), and M. massiliense (0.9%).In patients over the age of 70 years, the proportion of NTM among the isolates increased from 26.6% in 2007 to 62.0% in 2019, and that of M. intracellulare isolates among the NTM increased from 13.9% (11/79) in 2007 to 37.4% (175/468) in 2019. @*Conclusion@#The number of NTM isolates continuously increased over the study period, and the increase in the proportion of M. intracellulare in patients aged over 70 years was notable.