• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2007-2010
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• 2015

A new chemical inhibitor against severe acute respiratory syndrome (SARS) coronavirus helicase, 7-ethyl-8-mercapto-3-methyl-3,7-dihydro-1H-purine-2,6-dione, was identified. We investigated the inhibitory effect of the compound by conducting colorimetry-based ATP hydrolysis assay and fluorescence resonance energy transfer-based double-stranded DNA unwinding assay. The compound suppressed both ATP hydrolysis and double-stranded DNA unwinding activities of helicase with IC₅₀ values of 8.66 ± 0.26 μM and 41.6 ± 2.3 μM, respectively. Moreover, we observed that the compound did not show cytotoxicity up to 80 μM concentration. Our results suggest that the compound might serve as a SARS coronavirus inhibitor.

• Clinical and Experimental Pediatrics
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• v.64 no.7
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• pp.328-338
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• 2021

Humanity has been suffering from the global severe acute respiratory syndrome coronavirus 2 pandemic that began late in 2019. In 2020, for the first time in history, new vaccine platforms-including mRNA vaccines and viral vector-based DNA vaccines-have been given emergency use authorization, leading to mass vaccinations. The purpose of this article is to review the currently most widely used coronavirus disease 2019 vaccines, investigate their immunogenicity and efficacy data, and analyze the vaccine safety profiles that have been published, to date.

• Sleep Medicine and Psychophysiology
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• v.29 no.2
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• pp.29-34
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• 2022

Coronavirus disease 2019 (COVID-19), which was a global pandemic caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), is still a serious public health problem. COVID-19 causes various symptoms not only in the respiratory system but also in various parts of the body and has a significant effect on sleep. Insomnia and poor sleep quality were observed at high rates in patients with COVID-19 as well as in the uninfected general population. Obstructive sleep apnea is also considered a risk factor in patients with severe COVID-19. Virus-induced central nervous system damage is likely to be the cause of many sleep disorders in COVID-19, but psychosocial influences also seem to have played a significant role. Sleep problems persisted at high rates for a considerable period after the infection phase was over. More attention and research on the effect of COVID-19 on sleep is needed in the future.

• Journal of Chest Surgery
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• v.56 no.2
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• pp.128-135
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• 2023

Background: Pneumonia caused by severe acute respiratory syndrome coronavirus 2 can cause acute respiratory distress syndrome, often requiring prolonged mechanical ventilation and eventually tracheostomy. Both procedures occur in isolation units where personal protective equipment is needed. Additionally, the high bleeding risk in patients with extracorporeal membrane oxygenation (ECMO) places a great strain on surgeons. We investigated the clinical characteristics and outcomes of percutaneous dilatational tracheostomy (PDT) in patients with coronavirus disease 2019 (COVID-19) supported by ECMO, and compared the outcomes of patients with and without ECMO. Methods: This retrospective, single-center, observational study included patients with severe COVID-19 who underwent elective PDT (n=29) from April 1, 2020, to October 31, 2021. The patients were divided into ECMO and non-ECMO groups. Data were collected from electronic medical records at Ajou University Hospital in Suwon, Korea. Results: Twenty-nine COVID-19 patients underwent PDT (24 men [82.8%] and 5 women [17.2%]; median age, 61 years; range, 26-87 years; interquartile range, 54-71 years). The mean procedure time was 17±10.07 minutes. No clinically or statistically significant difference in procedure time was noted between the ECMO and non-ECMO groups (16.35±7.34 vs. 18.25±13.32, p=0.661). Overall, 12 patients (41.4%) had minor complications; 10 had mild subdermal bleeding from the skin incision, which was resolved with local gauze packing, and 2 (6.9%) had dislodgement. No healthcare provider infection was reported. Conclusion: Our PDT approach is safe for patients and healthcare providers. With bronchoscopy assistance, PDT can be performed quickly and easily even in isolation units and with acceptable risk, regardless of the hypo-coagulable condition of patients on ECMO.

• Molecules and Cells
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• v.45 no.12
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• pp.911-922
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• 2022

A structural protein of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), nucleocapsid (N) protein is phosphorylated by glycogen synthase kinase (GSK)-3 on the serine/arginine (SR) rich motif located in disordered regions. Although phosphorylation by GSK-3β constitutes a critical event for viral replication, the molecular mechanism underlying N phosphorylation is not well understood. In this study, we found the putative alpha-helix L/FxxxL/AxxRL motif known as the GSK-3 interacting domain (GID), found in many endogenous GSK-3β binding proteins, such as Axins, FRATs, WWOX, and GSKIP. Indeed, N interacts with GSK-3β similarly to Axin, and Leu to Glu substitution of the GID abolished the interaction, with loss of N phosphorylation. The N phosphorylation is also required for its structural loading in a virus-like particle (VLP). Compared to other coronaviruses, N of Sarbecovirus lineage including bat RaTG13 harbors a CDK1-primed phosphorylation site and Gly-rich linker for enhanced phosphorylation by GSK-3β. Furthermore, we found that the S202R mutant found in Delta and R203K/G204R mutant found in the Omicron variant allow increased abundance and hyper-phosphorylation of N. Our observations suggest that GID and mutations for increased phosphorylation in N may have contributed to the evolution of variants.

• Journal of Veterinary Science
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• v.22 no.5
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• pp.72.1-72.15
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• 2021

It has been speculated that bats serve as reservoirs of a huge variety of emerging coronaviruses (CoVs) that have been responsible for severe havoc in human health systems as well as negatively affecting human economic and social systems. A prime example is the currently active severe acute respiratory syndrome (SARS)-CoV2, which presumably originated from bats, demonstrating that the risk of a new outbreak of bat coronavirus is always latent. Therefore, an in-depth investigation to better comprehend bat CoVs has become an important issue within the international community, a group that aims to attenuate the consequences of future outbreaks. In this review, we present a concise introduction to CoVs found in bats and discuss their distribution in Southeast Asia. We also discuss the unique adaptation features in bats that confer the ability to be a potential coronavirus reservoir. In addition, we review the bat coronavirus-linked diseases that have emerged in the last two decades. Finally, we propose key factors helpful in the prediction of a novel coronavirus outbreak and present the most recent methods used to forecast an evolving outbreak.

• Clinical and Experimental Pediatrics
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• v.65 no.4
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• pp.167-171
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• 2022

In the era of the coronavirus disease 2019 (COVID-19) pandemic, countries worldwide have implemented several nonpharmaceutical interventions (NPIs) to contain its spread before vaccines and treatments were developed. NPIs included social distancing, mask wearing, intensive contact tracing and isolation, and sanitization. In addition to their effectiveness at preventing the rapid spread of COVID-19, NPIs have caused secondary changes in the epidemiology of other infectious diseases. In Korea, various NPI stages have been implemented since the first confirmed case of COVID-19 on January 20, 2020. This review, based on a PubMed database search, shows the impact of NPIs on several infectious diseases other than severe acute respiratory syndrome coronavirus 2 in the COVID-19 pandemic era in Korea.

• IMMUNE NETWORK
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• v.20 no.6
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• pp.44.1-44.19
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• 2020

The human body is continuously threatened by pathogens, and the immune system must maintain a balance between fighting infection and becoming over-activated. Mucosal surfaces cover several anatomically diverse organs throughout the body, such as the respiratory and gastrointestinal tracts, and are directly exposed to the external environment. Various pathogens invade the body through mucosal surfaces, making the mucosa the frontline of immune defense. The immune systems of various mucosal tissues display distinctive features that reflect the tissues' anatomical and functional characteristics. This review discusses the cellular components that constitute the respiratory and gastrointestinal tracts; in particular, it highlights the complex interactions between epithelial and immune cells to induce Ag-specific immune responses in the lung and gut. This information on mucosal immunity may facilitate understanding of the defense mechanisms against infectious agents that invade mucosal surfaces, such as severe acute respiratory syndrome coronavirus 2, and provide insight into effective vaccine development.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1073-1085
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• 2022

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has continued for over 2 years, following the outbreak of coronavirus-19 (COVID-19) in 2019. It has resulted in enormous casualties and severe economic crises. The rapid development of vaccines and therapeutics against SARS-CoV-2 has helped slow the spread. In the meantime, various mutations in the SARS-CoV-2 have emerged to evade current vaccines and therapeutics. A better understanding of SARS-CoV-2 pathogenesis is a prerequisite for developing efficient, advanced vaccines and therapeutics. Since the outbreak of COVID-19, a tremendous amount of research has been conducted to unveil SARS-CoV-2 pathogenesis, from clinical observations to biochemical analysis at the molecular level upon viral infection. In this review, we discuss the molecular mechanisms of SARS-CoV-2 propagation and pathogenesis, with an update on recent advances.

• Clinical Nutrition Research
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• v.12 no.1
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• pp.77-89
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• 2023

This study aimed to find out the effect of vitamins on respiratory-related viral infections, including coronavirus disease 2019 (COVID-19), through the literature reviews. From January 2000 to June 2021, the studies (cohort studies, cross-sectional studies, case-control studies, randomized control trials) related to vitamins (vitamin A, D, E, C, B₆, folate, and B₁₂) and COVID-19/severe acute respiratory syndrome/Middle East respiratory syndrome/cold/influenza were selected from the PubMed, Embase, and Cochrane libraries and analyzed. The relationship between vitamins and virus-related respiratory diseases was identified. Through the review, 39 studies were selected on vitamin D, one study on vitamin E, 11 studies on vitamin C, and 3 studies on folate. Regarding COVID-19, 18 studies on vitamin D, 4 studies on vitamin C, and 2 studies on folate showed significant effects of the intake of these nutrients in preventing COVID-19. Regarding colds and influenza, 3 studies on vitamin D, 1 study on vitamin E, 3 studies on vitamin C, and 1 study on folate demonstrated that the intake of these nutrients significantly prevents these diseases. Therefore, this review suggested the intake of vitamins D, E, C, and folate is important for preventing respiratory diseases related to viruses, such as COVID-19, colds, and influenza. The relationship between these nutrients and virus-related respiratory diseases should be continuously monitored in the future.