Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Background: As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research. Results: In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research. Conclusions This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.

Coronavirus disease 2019 vaccinations for healthcare workers (HCWs) have begun in South Korea. To investigate adverse events (AEs) of the first dose of each vaccine, any symptom was collected daily for seven days after vaccination in a tertiary hospital. We found that 1,301 of 1,403 ChAdOx1 nCoV-19 recipients and 38 of 80 BNT162b2 recipients reported AEs respectively (90.9% vs. 52.5%): injection-site pain (77.7% vs. 51.2%), myalgia (60.5% vs.11.2%), fatigue (50.7% vs. 7.5%), headache (47.4% vs. 7.5%), and fever (36.1% vs. 5%; P < 0.001 for all). Young HCWs reported more AEs with ChAdOx1 nCoV-19 than with BNT162b2.No incidences of anaphylaxis were observed. Only one serious AE required hospitalization for serious vomiting, and completely recovered. In conclusion, reported AEs were more common in recipients with ChAdOx1 nCoV-19 than in those with BNT162b2. However, most of the reported AEs were mild to moderate in severity. Sufficient explanation and preparation for expected AEs required to promote widespread vaccination.

Background: The coronavirus disease 2019 (COVID-19) pandemic has impacted various aspects of daily living and has influenced the life of every individual in a unique way.Acute myocardial infarction (AMI) is associated with high morbidity and mortality; thus, timely treatment is crucial to prevent poor prognosis. Therefore, an immediate emergency department (ED) visit is required; however, no domestic studies have reported the effect of COVID-19 on ED visits by patients with AMI. Therefore, this study aimed to assess the changes in the pattern of ED visits by patients with AMI by comparing visits during the COVID-19 outbreak period to those during two control periods. Methods: This nationwide, retrospective study used registry data of the National Emergency Department Information System. The ‘outbreak period’ was defined as the period between February 21, 2020 and April 1, 2020, while the ‘control period’ was defined as the same time period in the preceding two years (2018 and 2019). The primary outcome of our study was the number of patients admitted to the ED owing to AMI during the outbreak and control periods. Secondary outcomes were time from symptom onset to ED visit, length of ED stay, and 30-day mortality following admission. Results: During the outbreak period, 401,378 patients visited the ED; this number was lower than that during the control periods (2018: 577,548; 2019: 598,514). The number of patients with AMI visiting the ED was lower during the outbreak period (2,221) than during 2018 (2,437) and 2019 (2,591). Conclusion The COVID-19 pandemic has caused a reduction in ED visits by patients with AMI. We assume that this could likely be caused by misinterpretation of AMI symptoms as symptoms of respiratory infection, fear of contracting severe acute respiratory syndrome coronavirus 2, and restrictions in accessing emergency medical care owing to overburdened healthcare facilities. This study sheds light on the fact that healthcare and emergency medical staff members must work towards eliminating hurdles due to this pandemic for patients to receive timely emergency care, which in turn will help curb the growing burden of mortality.

Background and Objectives: Prior studies have shown that stroke patients treated with percutaneous left atrial appendage occlusion (LAAO) for non-valvular atrial fibrillation (NVAF) experience better outcomes than similar patients treated with warfarin. We investigated the impact of percutaneous left atrial appendage closure on post-stroke neurological outcomes in NVAF patients, compared with non-vitamin K antagonist oral anticoagulant (NOAC) therapy. Methods: Medical records for 1,427 patients in multiple registries and for 1,792 consecutive patients at 6 Korean hospitals were reviewed with respect to LAAO or NOAC treatment.Stroke severity in patients who experienced ischemic stroke or transient ischemic attack after either treatment was assessed with modified Rankin Scale (mRS) scoring at hospital discharge and at 3 and 12 months post-stroke. Results: mRS scores were significantly lower in LAAO patients at 3 (p<0.01) and 12 months (p<0.01) post-stroke, despite no significant differences in scores before the ischemic cerebrovascular event (p=0.22). The occurrences of disabling ischemic stroke in the LAAO and NOAC groups were 36.7% and 44.2% at discharge (p=0.47), 23.3% and 44.2% at 3 months post-stroke (p=0.04), and 13.3% and 43.0% at 12 months post-stroke (p=0.01), respectively.Recovery rates for disabling ischemic stroke at discharge to 12 months post-stroke were significantly higher for LAAO patients (50.0%) than for NOAC patients (5.6%) (p<0.01). Conclusions Percutaneous LAAO was associated with more favorable neurological outcomes after ischemic cerebrovascular event than NOAC treatment.

Coronavirus disease 2019 vaccinations for healthcare workers (HCWs) have begun in South Korea. To investigate adverse events (AEs) of the first dose of each vaccine, any symptom was collected daily for seven days after vaccination in a tertiary hospital. We found that 1,301 of 1,403 ChAdOx1 nCoV-19 recipients and 38 of 80 BNT162b2 recipients reported AEs respectively (90.9% vs. 52.5%): injection-site pain (77.7% vs. 51.2%), myalgia (60.5% vs.11.2%), fatigue (50.7% vs. 7.5%), headache (47.4% vs. 7.5%), and fever (36.1% vs. 5%; P < 0.001 for all). Young HCWs reported more AEs with ChAdOx1 nCoV-19 than with BNT162b2.No incidences of anaphylaxis were observed. Only one serious AE required hospitalization for serious vomiting, and completely recovered. In conclusion, reported AEs were more common in recipients with ChAdOx1 nCoV-19 than in those with BNT162b2. However, most of the reported AEs were mild to moderate in severity. Sufficient explanation and preparation for expected AEs required to promote widespread vaccination.

Background: The coronavirus disease 2019 (COVID-19) pandemic has impacted various aspects of daily living and has influenced the life of every individual in a unique way.Acute myocardial infarction (AMI) is associated with high morbidity and mortality; thus, timely treatment is crucial to prevent poor prognosis. Therefore, an immediate emergency department (ED) visit is required; however, no domestic studies have reported the effect of COVID-19 on ED visits by patients with AMI. Therefore, this study aimed to assess the changes in the pattern of ED visits by patients with AMI by comparing visits during the COVID-19 outbreak period to those during two control periods. Methods: This nationwide, retrospective study used registry data of the National Emergency Department Information System. The ‘outbreak period’ was defined as the period between February 21, 2020 and April 1, 2020, while the ‘control period’ was defined as the same time period in the preceding two years (2018 and 2019). The primary outcome of our study was the number of patients admitted to the ED owing to AMI during the outbreak and control periods. Secondary outcomes were time from symptom onset to ED visit, length of ED stay, and 30-day mortality following admission. Results: During the outbreak period, 401,378 patients visited the ED; this number was lower than that during the control periods (2018: 577,548; 2019: 598,514). The number of patients with AMI visiting the ED was lower during the outbreak period (2,221) than during 2018 (2,437) and 2019 (2,591). Conclusion The COVID-19 pandemic has caused a reduction in ED visits by patients with AMI. We assume that this could likely be caused by misinterpretation of AMI symptoms as symptoms of respiratory infection, fear of contracting severe acute respiratory syndrome coronavirus 2, and restrictions in accessing emergency medical care owing to overburdened healthcare facilities. This study sheds light on the fact that healthcare and emergency medical staff members must work towards eliminating hurdles due to this pandemic for patients to receive timely emergency care, which in turn will help curb the growing burden of mortality.

Background and Objectives: Prior studies have shown that stroke patients treated with percutaneous left atrial appendage occlusion (LAAO) for non-valvular atrial fibrillation (NVAF) experience better outcomes than similar patients treated with warfarin. We investigated the impact of percutaneous left atrial appendage closure on post-stroke neurological outcomes in NVAF patients, compared with non-vitamin K antagonist oral anticoagulant (NOAC) therapy. Methods: Medical records for 1,427 patients in multiple registries and for 1,792 consecutive patients at 6 Korean hospitals were reviewed with respect to LAAO or NOAC treatment.Stroke severity in patients who experienced ischemic stroke or transient ischemic attack after either treatment was assessed with modified Rankin Scale (mRS) scoring at hospital discharge and at 3 and 12 months post-stroke. Results: mRS scores were significantly lower in LAAO patients at 3 (p<0.01) and 12 months (p<0.01) post-stroke, despite no significant differences in scores before the ischemic cerebrovascular event (p=0.22). The occurrences of disabling ischemic stroke in the LAAO and NOAC groups were 36.7% and 44.2% at discharge (p=0.47), 23.3% and 44.2% at 3 months post-stroke (p=0.04), and 13.3% and 43.0% at 12 months post-stroke (p=0.01), respectively.Recovery rates for disabling ischemic stroke at discharge to 12 months post-stroke were significantly higher for LAAO patients (50.0%) than for NOAC patients (5.6%) (p<0.01). Conclusions Percutaneous LAAO was associated with more favorable neurological outcomes after ischemic cerebrovascular event than NOAC treatment.

The first edition of the ‘Standardized Pathology Report for Colorectal Cancer,’ which was developed by the Gastrointestinal Pathology Study Group (GIP) of the Korean Society of Pathologists, was published 13 years ago. Meanwhile, there have been many changes in the pathologic diagnosis of colorectal cancer (CRC), pathologic findings included in the pathology report, and immunohistochemical and molecular pathology required for the diagnosis and treatment of colorectal cancer. In order to reflect these changes, we (GIP) decided to make the second edition of the report. The purpose of this standardized pathology report is to provide a practical protocol for Korean pathologists, which could help diagnose and treat CRC patients. This report consists of “standard data elements” and “conditional data elements.” Basic pathologic findings and parts necessary for prognostication of CRC patients are classified as “standard data elements,” while other prognostic factors and factors related to adjuvant therapy are classified as “conditional data elements” so that each institution could select the contents according to the characteristics of the institution. The Korean version is also provided separately so that Korean pathologists can easily understand and use this report. We hope that this report will be helpful in the daily practice of CRC diagnosis.

BACKGROUND: Though clinical practice guidelines (CPGs) for cardiac rehabilitation (CR) are an effective and widely used treatment method worldwide, they are as yet not widely accepted in Korea. Given that cardiovascular disease is the second leading cause of death in Korea, it is urgent that CR programs be developed. In 2008, the Government of Korea implemented CR programs at 11 university hospitals as part of its Regional Cardio-Cerebrovascular Center Project, and 3 additional medical facilities will be added in 2019. In addition, owing to the promotion of CR nationwide and the introduction of CR insurance benefits, 40 medical institutions nationwide have begun CR programs even as a growing number of medical institutions are preparing to offer CR. The purpose of this research was to develop evidence-based CPGs to support CR implementation in Korea. METHODS: This study is based on an analysis of CPGs elsewhere in the world, an extensive literature search, a systematic analysis of multiple randomized control trials, and a CPG management, development, and assessment committee comprised of 33 authors—primarily rehabilitation specialists, cardiologists, and thoracic surgeons in 21 university hospitals and 2 general hospitals. Twelve consultants, primarily rehabilitation, sports medicine, and preventive medicine specialists, CPG experts, nurses, physical therapists, clinical nutritionists, and library and information experts participated in the research and development of these CPGs. After the draft guidelines were developed, 3 rounds of public hearings were held with staff members from relevant academic societies and stakeholders, after which the guidelines were further reviewed and modified. RESULTS: CR involves a more cost-effective use of healthcare resources relative to that of general treatments, and the exercise component of CR lowers cardiovascular mortality and readmission rates, regardless of the type of coronary heart disease and type and setting of CR. CONCLUSION: Individualized CR programs should be considered together with various factors, including differences in heart function and lifestyle, and doing so will boost participation and adherence with the CR program, ultimately meeting the final goals of the program, namely reducing the recurrence of myocardial infarction and mortality rates.
Acute Coronary Syndrome ; Cardiovascular Diseases ; Cause of Death ; Consultants ; Coronary Disease ; Delivery of Health Care ; Heart ; Hospitals, General ; Hospitals, University ; Humans ; Insurance Benefits ; Korea ; Life Style ; Methods ; Mortality ; Myocardial Infarction ; Nutritionists ; Physical Therapists ; Preventive Medicine ; Recurrence ; Rehabilitation ; Secondary Prevention ; Specialization ; Sports Medicine ; Surgeons