• 한국환경보건학회지
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• 제48권2호
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• pp.116-122
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• 2022

Background: The recent COVID-19 pandemic is one of the worst disease outbreaks of the 21th century. Due to a lack of reliable antiviral therapeutics, wearing face masks is recommended to prevent airborne infection originating from virus-contaminated bioaerosols. Objectives: The aim of this study was to evaluate the filtration efficiencies of face masks that are commercially available in South Korea for a biological aerosol of Staphylococcus aureus (S. aureus) and murine coronavirus, a well-known surrogate for human coronaviruses. Methods: We collected six different kinds of commercial masks: two Korea Filter (KF)94 (KF94-1, KF94-2) masks, one surgical (Surgical-1) mask, one anti-droplet (KF-AD-1) mask, and two dust (Dust-1, Dust-2) face masks. S. aureus (ATCC 6538), a well-performing test bacteria and murine coronavirus (ATCC VR-764) were prepared under a suitable culture condition. Then, a mask biological filtration tester was used to examine the microbial filtration efficiencies of masks. Test microorganisms were quantitatively measured via cultivation methods and microbial filtration efficiencies were calculated appropriately. Results: All face masks showed over 99.6% filtration efficiency for S. aureus or murine coronavirus. There were no significant differences among the bacterial filtration efficiencies of the face masks. KF94-1 (99.97±0.08%) and Dust-1 mask (99.97±0.07%) showed the highest (over 99.9%) filtration efficiency for murine coronavirus. KF94-1 or Dust-1 masks showed a significant virus filtration efficiency compared to Surgical-1 mask (p<0.05; Mann-Whitney U test). Conclusions: All the commercially available face masks used in this study can filter S. aureus or murine coronavirus in bioaerosols efficiently, regardless of the mask type. Therefore, our results suggest that wearing a certified face mask is a reliable means to prevent the transmission of infectious airborne diseases via biological aerosols.

• Journal of Veterinary Science
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• 제22권3호
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• pp.36.1-36.12
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• 2021

Background: Mouse hepatitis virus (MHV) A59 is a highly infectious pathogen and starts in the respiratory tract and progresses to systemic infection in laboratory mice. The complement system is an important part of the host immune response to viral infection. It is not clear the role of the classical complement pathway in MHV infection. Objectives: The purpose of this study was to determine the importance of the classical pathway in coronavirus pathogenesis by comparing C1qa KO mice and wild-type mice. Methods: We generated a C1qa KO mouse using CRISPR/Cas9 technology and compared the susceptibility to MHV A59 infection between C1qa KO and wild-type mice. Histopathological and immunohistochemical changes, viral loads, and chemokine expressions in both mice were measured. Results: MHV A59-infected C1qa KO mice showed severe histopathological changes, such as hepatocellular necrosis and interstitial pneumonia, compared to MHV A59-infected wild-type mice. Virus copy numbers in the olfactory bulb, liver, and lungs of C1qa KO mice were significantly higher than those of wild-type mice. The increase in viral copy numbers in C1qa KO mice was consistent with the histopathologic changes in organs. These results indicate that C1qa deficiency enhances susceptibility to MHV A59 systemic infection in mice. In addition, this enhanced susceptibility effect is associated with dramatic elevations in spleen IFN-γ, MIP-1 α, and MCP-1 in C1qa KO mice. Conclusions: These data suggest that C1qa deficiency enhances susceptibility to MHV A59 systemic infection, and activation of the classical complement pathway may be important for protecting the host against MHV A59 infection.

• Journal of Preventive Medicine and Public Health
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• 제56권3호
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• pp.212-220
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• 2023

Objectives: This study compared the epidemiological and clinical manifestations of patients hospitalized with respiratory syncytial virus (RSV) infection before and during the coronavirus disease 2019 (COVID-19) pandemic at a tertiary care hospital in Chiang Mai Province, Thailand. Methods: This retrospective observational study utilized data from all cases of laboratory-confirmed RSV infection at Maharaj Nakorn Chiang Mai Hospital from January 2016 to December 2021. Differences in the clinical presentation of RSV infection before (2016 to 2019) and during (2020 to 2021) the COVID-19 pandemic were analyzed and compared. Results: In total, 358 patients hospitalized with RSV infections were reported from January 2016 to December 2021. During the COVID-19 pandemic, only 74 cases of hospitalized RSV infection were reported. Compared to pre-pandemic levels, the clinical presentations of RSV infection showed statistically significant decreases in fever on admission (p=0.004), productive cough (p=0.004), sputum (p=0.003), nausea (p=0.03), cyanosis (p=0.004), pallor (p<0.001), diarrhea (p<0.001), and chest pain (p<0.001). Furthermore, vigilant measures to prevent the spread of COVID-19, including lockdowns, also interrupted the RSV season in Thailand from 2020 to 2021. Conclusions: The incidence of RSV infection was affected by the COVID-19 pandemic in Chiang Mai Province, Thailand, which also changed the clinical presentation and seasonal pattern of RSV infection in children.

• Journal of Microbiology and Biotechnology
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• 제30권4호
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• pp.515-525
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• 2020

Interferon (IFN)-λ plays an essential role in mucosal cells which exhibit strong antiviral activity. Lactobacillus plantarum (L. plantarum) has substantial application potential in the food and medical industries because of its probiotic properties. Alphacoronaviruses, especially porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), cause high morbidity and mortality in piglets resulting in economic loss. Co-infection by these two viruses is becoming increasingly frequent. Therefore, it is particularly important to develop a new drug to prevent diarrhea infected with mixed viruses in piglets. In this study, we first constructed an anchored expression vector with CWA (C-terminal cell wall anchor) on L. plantarum. Second, we constructed two recombinant L. plantarum strains that anchored IFN-λ3 via pgsA (N-terminal transmembrane anchor) and CWA. Third, we demonstrated that both recombinant strains possess strong antiviral effects against coronavirus infection in the intestinal porcine epithelial cell line J2 (IPEC-J2). However, recombinant L. plantarum with the CWA anchor exhibited a more powerful antiviral effect than recombinant L. plantarum with pgsA. Consistent with this finding, Lb.plantarum-pSIP-409-IFN-λ3-CWA enhanced the expression levels of IFN-stimulated genes (ISGs) (ISG15, OASL, and Mx1) in IPEC-J2 cells more than did recombinant Lb.plantarum-pSIP-409-pgsA'-IFN-λ3. Our study verifies that recombinant L. plantarum inhibits PEDV and TGEV infection in IPEC-J2 cells, which may offer great potential for use as a novel oral antiviral agent in therapeutic applications for combating porcine epidemic diarrhea and transmissible gastroenteritis. This study is the first to show that recombinant L. plantarum suppresses PEDV and TGEV infection of IPEC-J2 cells.

• 대한임상검사과학회지
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• 제54권2호
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• pp.103-109
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• 2022

2019년 12월 중국에서 바이러스성 폐렴을 일으키는 코로나 바이러스 질병 2019 (COVID-19)가 검출돼 전 세계로 빠르게 확산되어 수백만 명의 감염자와 사망자가 발생했다. 증상이 유사한 호흡기 바이러스 가운데 경기도의료원에 입원한 환자 35명이 2020년 11월부터 2021년 1월까지 인플루엔자 바이러스(인플루엔자바이러스 A·B)에 감염된 것으로 나타났다. 이들 환자의 기록과 건강검진을 위해 병원을 찾은 환자의 기록을 비교했다. 대상 환자 군에는 COVID-19 환자 30명, 인플루엔자 환자 5명, 비 감염 환자 121명이 포함됐다. 혈액학적 기록을 활용해 입원 당일 실시한 일반 혈액 검사와 생화학 검사 결과를 분석했다. COVID-19 및 인플루엔자에 동반 감염된 환자들은 단일 COVID-19 감염 그룹보다 젖산 탈수소효소(LDH), C-반응 단백질(CRP), 백혈구(WBC) 수치가 유의미하게 높았다. 적혈구 침전률과 COVID-19 감염 환자만 있는 림프구(Lymphocyte)가 다른 그룹에 비해 증가했다. 인플루엔자 감염군은 COVID-19와 인플루엔자에 동반 감염된 환자에 비해 발열의 빈도가 빈번했다. COVID-19에 감염된 단일 환자에 비해 공동 감염 그룹에서 유의미한 임상 특이 수치가 관찰되었다. 본 연구에서 나오는 결과로 COVID-19치료제와 백신개발에 이용하기를 기대한다.

• Journal of Preventive Medicine and Public Health
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• 제53권3호
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• pp.168-170
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• 2020

On December 31, 2019, the Chinese government officially announced that the country had some cases of pneumonia with an unknown cause. By February 8, 2020, there were 24 confirmed cases in Korea, and the number of cases has steadily increased since then. On March 9, 2020, the cumulative number of confirmed cases in Korea was 7382, with 51 deaths. This study examines the characteristics of the coronavirus disease 2019 (COVID-19) outbreak from the perspective of the large-scale number of confirmed COVID-19 cases and deaths. This study is significant in that it emphasizes the precautionary principle in preventing and managing infectious diseases, and makes suggestions for urgently needed public health policies.

• International Journal of Contents
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• 제17권3호
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• pp.1-14
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• 2021

Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, a lot of efforts have been made in the field of data science to help combat against this disease. Among them, forecasting the number of cases of infection is a crucial problem to predict the development of the pandemic. Many deep learning-based models can be applied to solve this type of time series problem. In this research, we would like to take a step forward to incorporate spatial data (geography) with time series data to forecast the cases of region-level infection simultaneously. Specifically, we model a single spatio-temporal graph, in which nodes represent the geographic regions, spatial edges represent the distance between each pair of regions, and temporal edges indicate the node features through time. We evaluate this approach in COVID-19 in a Korean dataset, and we show a decrease of approximately 10% in both RMSE and MAE, and a significant boost to the training speed compared to the baseline models. Moreover, the training efficiency allows this approach to be extended for a large-scale spatio-temporal dataset.

• Journal of Veterinary Science
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• 제23권6호
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• pp.80.1-80.6
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• 2022

A 10-year-old male neutered Labrador Retriever presented with a history of acute-onset tachypnoea, lethargy and anorexia. The dog was pyrexic, tachypnoeic and dyspnoeic on examination. A rapid antigen test for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was performed on an oropharyngeal swab and yielded a positive result. SARS-CoV-2 infection was subsequently confirmed by reverse transcription polymerase chain reaction (RT-PCR) analysis. Both of the dog's owners had positive rapid antigen test and RT-PCR analysis results for SARS-CoV-2. Additional diagnostics included computed tomography. Resolution of the dog's clinical signs was achieved with symptomatic treatment.

• 항공우주의학회지
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• 제31권1호
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• pp.17-20
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• 2021

As the coronavirus disease 2019 (COVID-19) pandemic continues, doctors face many difficulties in managing patients with respiratory allergies. As research continues, much new knowledge has emerged about the link between COVID-19 infection and respiratory allergies. Studies to date have shown that there is no significant increase in the risk of COVID-19 infection in patients with respiratory allergies. However, in patients undergoing treatment for moderate to severe asthma or allergic rhinitis, more severe clinical manifestations, increased hospitalization period, and increased mortality may occur, so patients need to be managed with more care. In addition to personal efforts, social consideration should be accompanied to prevent deterioration in patients' quality of life with respiratory allergies due to COVID-19. Lastly, as clinical doctors, we should treat patients with respiratory allergies to protect ourselves appropriately by actively utilizing remote medical treatment and minimizing tests that generate droplets. Also, by appropriately educating patients and continuing drug treatment, efforts should be made to ensure that patients receive the best treatment even in a pandemic situation.

• Clinics in Shoulder and Elbow
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• 제25권3호
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• pp.236-239
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• 2022

The objective of this article is to describe intraoperative pulmonary embolism during shoulder arthroscopy in a patient with previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Further, we describe how the pandemic has influenced the population by increasing the rate of embolisms. Awareness of such cases will help to increase knowledge regarding SARS-Cov-2 and to determine if such patients should receive routine antithrombotic prophylaxis.