1.Activation of autophagy at cerebral cortex and apoptosis at brainstem are differential responses to 835 MHz RF-EMF exposure.
Ju Hwan KIM ; Da Hyeon YU ; Hak Rim KIM
The Korean Journal of Physiology and Pharmacology 2017;21(2):179-188
With the explosive increase in exposure to radiofrequency electromagnetic fields (RF-EMF) emitted by mobile phones, public concerns have grown over the last few decades with regard to the potential effects of EMF exposure on the nervous system in the brain. Many researchers have suggested that RF-EMFs can effect diverse neuronal alterations in the brain, thereby affecting neuronal functions as well as behavior. Previously, we showed that long-term exposure to 835 MHz RF-EMF induces autophagy in the mice brain. In this study, we explore whether short-term exposure to RF-EMF leads to the autophagy pathway in the cerebral cortex and brainstem at 835 MHz with a specific absorption rate (SAR) of 4.0 W/kg for 4 weeks. Increased levels of autophagy genes and proteins such as LC3B-II and Beclin1 were demonstrated and the accumulation of autophagosomes and autolysosomes was observed in cortical neurons whereas apoptosis pathways were up-regulated in the brainstem but not in the cortex following 4 weeks of RF exposure. Taken together, the present study indicates that monthly exposure to RF-EMF induces autophagy in the cerebral cortex and suggests that autophagic degradation in cortical neurons against a stress of 835 MHz RF during 4 weeks could correspond to adaptation to the RF stress environment. However, activation of apoptosis rather than autophagy in the brainstem is suggesting the differential responses to the RF-EMF stresses in the brain system.
Absorption
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Animals
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Apoptosis*
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Autophagy*
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Brain
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Brain Stem*
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Cell Phones
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Cerebral Cortex*
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Electromagnetic Fields
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Mice
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Nervous System
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Neurons
2.A Suggestion to Develop a Nutrition Policy on Food and Nutrition Labeling and Education Systems for Fast Food and Carbonated Soft Drinks in Korea.
Sang Jin CHUNG ; Ju Hyeon KIM ; Jung Sug LEE ; Da Hee LEE ; Sook He KIM ; Choon Hie YU
The Korean Journal of Nutrition 2004;37(5):394-405
The objective of this study is to develop a nutrition policy on food and nutrition labeling and education systems for fast food and carbonated soft drinks in Korea by identifying the fast food and soft drink use and by examining nutrition policies and labeling in Korea and other countries. Fast food is defined as food dispensed quickly at a restaurant generally offering a limited menu of inexpensive items, which may be mostly not nutritious. It is a growing component of the Korean diet, especially on children and adolescent population. Low nutrient dense beverages such as carbonated drinks are also increasing in the children and adolescent's diet in Korea and concern has been raised that these beverages may replace more nutritious beverage and provide empty calories. According to 2001 Korean national health and nutrition survey, fast food and carbonated soft drinks were most popular among 13 - 19 years old adolescents. Thirty six and 72 percent of adolescents consumed hamburger and carbonated beverage equal to or more than once a week, respectively. In United States, all processed food including soft drinks should disclose full nutrition information by nutrition labeling requirement. Restaurant foods are not required to provide nutrition information currently, but legislation on mandatory nutrition labeling of fast foods with other restaurant foods has been proposed currently in US. The sales of foods of minimal nutritional value, such as soft drinks, in the nation's schools is regulated by the United States Department of Agriculture. Nutrition information about fast food in US has been provided by fast food companies, non-profit organizations, hospitals and government through internet, booklet and brochure, etc, but the information is available from only a few resources in Korea. This study suggests a nutrition policy on fast food and soft drink use which includes establishing mandatory nutrition labeling and developing nutrition education materials and programs by web-site, booklet and government and school programs in Korea.
Adolescent
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Beverages
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Carbon*
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Carbonated Beverages*
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Child
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Commerce
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Diet
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Education*
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Fast Foods*
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Food Labeling*
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Humans
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Internet
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Korea*
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Nutrition Policy*
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Nutrition Surveys
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Nutritive Value
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Organizations, Nonprofit
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Pamphlets
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Restaurants
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United States
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United States Department of Agriculture
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Young Adult
3.Evaluation of the color stability of light cured composite resins according to the resin matrices
Da Hye YU ; Hyun Jin JUNG ; Sung Hyeon CHOI ; In Nam HWANG
Korean Journal of Dental Materials 2019;46(2):109-120
The purpose of this study was to evaluate the color stability of light cured composite resins according to the resin matrices. Three kinds of resin matrices such as Bis-GMA (Venus® Diamond; VD), Silorane (FiltekTM P90; P90), and Ormocer (Admira; Ad) were selected. Each of them were used to prepare 30 specimens. The initial CIE L*a*b* values were measured by means of a Spectrophotometer (NF999, Nippon Denshoku, Japan). For accelerated aging process, the specimens were immersed in a circulating water bath with distilled water at 60℃. Spectrophotometric analyses were made after immersion of 8, 16, 24, 41 days and the color difference (ΔE*) was calculated. The L* value increased compared with initial L* value. VD had the greatest L* value change and Ad had the smallest L* value change (p<0.05). Ad had the greatest a* value change and VD had the smallest a* value change (p<0.05). The b* value of P90 increased steadily in positive value (+)(p<0.05). ΔE* of Ad had the smallest value and that of P90 had the greatest change with time. According to this study, the value of light cured composite resins was increased with water sorption and color of those changed into greenish and yellowish. And according to the evaluation of color stability, Ad with Ormocer as resin matrices had the best color stability with time in oral environment and P90 with Silorane as resin matrices had the lowest color stability with time. And VD had the greatest initial ΔE*.
Aging
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Baths
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Bisphenol A-Glycidyl Methacrylate
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Composite Resins
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Diamond
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Immersion
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Organically Modified Ceramics
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Silorane Resins
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Water
4.Relationship between Bronchodilator Response, Airway Hyperresponsiveness, and Exhaled Nitric Oxide Levels in Patients with Suspected Bronchial Asthma.
Sang Yu OH ; Min Hyung LEE ; Da Eun OH ; Gil Soon CHOI ; Seok Hyeon KIM ; Young Chan PARK ; Hee Kyoo KIM
Korean Journal of Medicine 2017;92(5):458-466
BACKGROUND/AIMS: Exhaled nitric oxide (NO) has been extensively investigated as a marker of airway inflammation in asthma, and fractional exhaled nitric oxide (FeNO) is recognized as a useful tool for its evaluation. The aim of this study was to investigate the relationships between FeNO levels and bronchodilator response (BDR), and between FeNO and mannitol-induced airway hyperresponsiveness (AHR), in patients with suspected asthma. METHODS: Clinical variables were collected from patients aged ≥ 13 years with suspected bronchial asthma and measured levels of FeNO. These levels were compared with patient values for forced expiratory volume in the first second (FEV1) and forced expiratory flow at 25 and 75% of the pulmonary volume (FEF(25-75%)) in bronchodilator response tests under control conditions, and during bronchial provocation with mannitol. Correlations and receiver operating characteristic (ROC) curves between FeNO levels and each test were assessed. RESULTS: A total of 259 patients were included in the analysis. The mean ages of the two test groups were 41.1 and 47.8 years, respectively. FeNO levels were strongly correlated with bronchodilator response (%) and with the mannitol dose producing a 15% fall in FEV1 (PD15). On the other hand, FeNO levels were only weakly correlated with FEF(25-75%). The optimal cut-off values for FeNO to predict a positive BDR and AHR were 38.5 and 29.5 parts per billion, respectively. CONCLUSIONS: This study suggests that FEV1 and FEF(25-75%) airway responses correlate with FeNO levels in patients with suspected bronchial asthma. FeNO levels may help to predict positive responses to BDR and AHR.
Asthma*
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Forced Expiratory Volume
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Hand
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Humans
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Inflammation
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Mannitol
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Nitric Oxide*
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ROC Curve
5.Word Embedding Reveals Cyfra 21-1 as a Biomarker for Chronic Obstructive Pulmonary Disease
Jeongwon HEO ; Da Hye MOON ; Yoonki HONG ; So Hyeon BAK ; Jeeyoung KIM ; Joo Hyun PARK ; Byoung-Doo OH ; Yu-Seop KIM ; Woo Jin KIM
Journal of Korean Medical Science 2021;36(35):e224-
Background:
Although patients with chronic obstructive pulmonary disease (COPD) experience high morbidity and mortality worldwide, few biomarkers are available for COPD.Here, we analyzed potential biomarkers for the diagnosis of COPD by using word embedding.
Methods:
To determine which biomarkers are likely to be associated with COPD, we selected respiratory disease-related biomarkers. Degrees of similarity between the 26 selected biomarkers and COPD were measured by word embedding. And we infer the similarity with COPD through the word embedding model trained in the large-capacity medical corpus, and search for biomarkers with high similarity among them. We used Word2Vec, Canonical Correlation Analysis, and Global Vector for word embedding. We evaluated the associations of selected biomarkers with COPD parameters in a cohort of patients with COPD.
Results:
Cytokeratin 19 fragment (Cyfra 21-1) was selected because of its high similarity and its significant correlation with the COPD phenotype. Serum Cyfra 21-1 levels were determined in patients with COPD and controls (4.3 ± 5.9 vs. 3.9 ± 3.6 ng/mL, P = 0.611). The emphysema index was significantly correlated with the serum Cyfra 21-1 level (correlation coefficient = 0.219,P = 0.015).
Conclusion
Word embedding may be used for the discovery of biomarkers for COPD and Cyfra 21-1 may be used as a biomarker for emphysema. Additional studies are needed to validate Cyfra 21-1 as a biomarker for COPD.
6.Word Embedding Reveals Cyfra 21-1 as a Biomarker for Chronic Obstructive Pulmonary Disease
Jeongwon HEO ; Da Hye MOON ; Yoonki HONG ; So Hyeon BAK ; Jeeyoung KIM ; Joo Hyun PARK ; Byoung-Doo OH ; Yu-Seop KIM ; Woo Jin KIM
Journal of Korean Medical Science 2021;36(35):e224-
Background:
Although patients with chronic obstructive pulmonary disease (COPD) experience high morbidity and mortality worldwide, few biomarkers are available for COPD.Here, we analyzed potential biomarkers for the diagnosis of COPD by using word embedding.
Methods:
To determine which biomarkers are likely to be associated with COPD, we selected respiratory disease-related biomarkers. Degrees of similarity between the 26 selected biomarkers and COPD were measured by word embedding. And we infer the similarity with COPD through the word embedding model trained in the large-capacity medical corpus, and search for biomarkers with high similarity among them. We used Word2Vec, Canonical Correlation Analysis, and Global Vector for word embedding. We evaluated the associations of selected biomarkers with COPD parameters in a cohort of patients with COPD.
Results:
Cytokeratin 19 fragment (Cyfra 21-1) was selected because of its high similarity and its significant correlation with the COPD phenotype. Serum Cyfra 21-1 levels were determined in patients with COPD and controls (4.3 ± 5.9 vs. 3.9 ± 3.6 ng/mL, P = 0.611). The emphysema index was significantly correlated with the serum Cyfra 21-1 level (correlation coefficient = 0.219,P = 0.015).
Conclusion
Word embedding may be used for the discovery of biomarkers for COPD and Cyfra 21-1 may be used as a biomarker for emphysema. Additional studies are needed to validate Cyfra 21-1 as a biomarker for COPD.
7.Influence of the microwave sintering period on the 3 point flexural strength and shade of zirconia restoration
Ji Hye KANG ; Kyung Min YU ; Ji Hyeon LEE ; Da Yeon SONG ; Jung Soo LEE ; Ji Hawn KIM ; Eun Jeong BAE
Korean Journal of Dental Materials 2018;45(3):147-154
In this study, we tried to confirm clinically applicable applicability by comparing the difference in 3 point flexural strength and shade of the prosthesis depending on microwave sintering time of dental CAD / CAM zirconia. 3 Point flexural strength specimens (n=30) and shade measurement specimens (n=28) were prepared and sintered at different sintering times. 3 point flexural strength and shade were measured and analyzed by independent t-test (α=0.05). Measurement result of 3 point flexural strength the average of short-term sintering (STS) was 245.47±29.89 MPa, the average of long-term sintering (LTS) was 284.27±31.56 MPa, and there was a statistically significant difference (p < 0.05). The shade measurement result ⊿E*(ab) showed the average STS of 1.51±0.48 and the LTS of 1.52±0.41, but there was no statistically significant difference (p>0.05). The 3 point flexural strength of the zirconia restorations fabricated by short time and long time was high in long time sintering. However, other conditions may be required for clinical applications. Since the shade test did not show any significant color difference according to sintering time, it is considered to be sufficient for clinical application.
Microwaves
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Prostheses and Implants
8.Optimization of Microenvironments Inducing Differentiation of Tonsil-Derived Mesenchymal Stem Cells into Endothelial Cell-Like Cells
Se Young OH ; Da Hyeon CHOI ; Yoon Mi JIN ; Yeonsil YU ; Ha Yeong KIM ; Gyungah KIM ; Yoon Shin PARK ; Inho JO
Tissue Engineering and Regenerative Medicine 2019;16(6):631-643
BACKGROUND: Stem cell engineering is appealing consideration for regenerating damaged endothelial cells (ECs) because stem cells can differentiate into EC-like cells. In this study, we demonstrate that tonsil-derived mesenchymal stem cells (TMSCs) can differentiate into EC-like cells under optimal physiochemical microenvironments.METHODS: TMSCs were preconditioned with Dulbecco's Modified Eagle Medium (DMEM) or EC growth medium (EGM) for 4 days and then replating them on Matrigel to observe the formation of a capillary-like network under light microscope. Microarray, quantitative real time polymerase chain reaction, Western blotting and immunofluorescence analyses were used to evaluate the expression of gene and protein of EC-related markers.RESULTS: Preconditioning TMSCs in EGM for 4 days and then replating them on Matrigel induced the formation of a capillary-like network in 3 h, but TMSCs preconditioned with DMEM did not form such a network. Genome analyses confirmed that EGM preconditioning significantly affected the expression of genes related to angiogenesis, blood vessel morphogenesis and development, and vascular development. Western blot analyses revealed that EGM preconditioning with gelatin coating induced the expression of endothelial nitric oxide synthase (eNOS), a mature EC-specific marker, as well as phosphorylated Akt at serine 473, a signaling molecule related to eNOS activation. Gelatin-coating during EGM preconditioning further enhanced the stability of the capillary-like network, and also resulted in the network more closely resembled to those observed in human umbilical vein endothelial cells.CONCLUSION: This study suggests that under specific conditions, i.e., EGM preconditioning with gelatin coating for 4 days followed by Matrigel, TMSCs could be a source of generating endothelial cells for treating vascular dysfunction.
Blood Vessels
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Blotting, Western
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Eagles
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Endothelial Cells
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Fluorescent Antibody Technique
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Gelatin
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Genome
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Human Umbilical Vein Endothelial Cells
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Mesenchymal Stromal Cells
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Morphogenesis
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Nitric Oxide Synthase Type III
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Palatine Tonsil
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Real-Time Polymerase Chain Reaction
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Serine
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Stem Cells
9.Clinical and Virologic Effectiveness of Remdesivir Treatment for Severe Coronavirus Disease 2019 (COVID-19) in Korea: a Nationwide Multicenter Retrospective Cohort Study
Eun-Jeong JOO ; Jae-Hoon KO ; Seong Eun KIM ; Seung-Ji KANG ; Ji Hyeon BAEK ; Eun Young HEO ; Hye Jin SHI ; Joong Sik EOM ; Pyoeng Gyun CHOE ; Seongman BAE ; Sang Hyun RA ; Da Young KIM ; Baek-Nam KIM ; Yu Min KANG ; Ji Yeon KIM ; Jin-Won CHUNG ; Hyun-Ha CHANG ; Sohyun BAE ; Shinhyea CHEON ; Yoonseon PARK ; Heun CHOI ; Eunjung LEE ; Bo young LEE ; Jung Wan PARK ; Yujin SOHN ; Jung Yeon HEO ; Sung-Han KIM ; Kyong Ran PECK
Journal of Korean Medical Science 2021;36(11):e83-
Background:
Remdesivir is widely used for the treatment of coronavirus disease 2019 (COVID-19), but controversies regarding its efficacy still remain.
Methods:
A retrospective cohort study was conducted to evaluate the effect of remdesivir on clinical and virologic outcomes of severe COVID-19 patients from June to July 2020. Primary clinical endpoints included clinical recovery, additional mechanical ventilator (MV) support, and duration of oxygen or MV support. Viral load reduction by hospital day (HD) 15 was evaluated by calculating changes in cycle threshold (Ct) values.
Results:
A total of 86 severe COVID-19 patients were evaluated including 48 remdesivirtreated patients. Baseline characteristics were not significantly different between the two groups. Remdesivir was administered an average of 7.42 days from symptom onset. The proportions of clinical recovery of the remdesivir and supportive care group at HD 14 (56.3% and 39.5%) and HD 28 (87.5% and 78.9%) were not statistically different. The proportion of patients requiring MV support by HD 28 was significantly lower in the remdesivir group than in the supportive care group (22.9% vs. 44.7%, P = 0.032), and MV duration was significantly shorter in the remdesivir group (average, 1.97 vs. 5.37 days; P = 0.017). Analysis of upper respiratory tract specimens demonstrated that increases of Ct value from HD 1–5 to 11–15 were significantly greater in the remdesivir group than the supportive care group (average, 10.19 vs. 5.36; P = 0.007), and the slope of the Ct value increase was also significantly steeper in the remdesivir group (average, 5.10 vs. 2.68; P = 0.007).
Conclusion
The remdesivir group showed clinical and virologic benefit in terms of MV requirement and viral load reduction, supporting remdesivir treatment for severe COVID-19.
10.Clinical and Virologic Effectiveness of Remdesivir Treatment for Severe Coronavirus Disease 2019 (COVID-19) in Korea: a Nationwide Multicenter Retrospective Cohort Study
Eun-Jeong JOO ; Jae-Hoon KO ; Seong Eun KIM ; Seung-Ji KANG ; Ji Hyeon BAEK ; Eun Young HEO ; Hye Jin SHI ; Joong Sik EOM ; Pyoeng Gyun CHOE ; Seongman BAE ; Sang Hyun RA ; Da Young KIM ; Baek-Nam KIM ; Yu Min KANG ; Ji Yeon KIM ; Jin-Won CHUNG ; Hyun-Ha CHANG ; Sohyun BAE ; Shinhyea CHEON ; Yoonseon PARK ; Heun CHOI ; Eunjung LEE ; Bo young LEE ; Jung Wan PARK ; Yujin SOHN ; Jung Yeon HEO ; Sung-Han KIM ; Kyong Ran PECK
Journal of Korean Medical Science 2021;36(11):e83-
Background:
Remdesivir is widely used for the treatment of coronavirus disease 2019 (COVID-19), but controversies regarding its efficacy still remain.
Methods:
A retrospective cohort study was conducted to evaluate the effect of remdesivir on clinical and virologic outcomes of severe COVID-19 patients from June to July 2020. Primary clinical endpoints included clinical recovery, additional mechanical ventilator (MV) support, and duration of oxygen or MV support. Viral load reduction by hospital day (HD) 15 was evaluated by calculating changes in cycle threshold (Ct) values.
Results:
A total of 86 severe COVID-19 patients were evaluated including 48 remdesivirtreated patients. Baseline characteristics were not significantly different between the two groups. Remdesivir was administered an average of 7.42 days from symptom onset. The proportions of clinical recovery of the remdesivir and supportive care group at HD 14 (56.3% and 39.5%) and HD 28 (87.5% and 78.9%) were not statistically different. The proportion of patients requiring MV support by HD 28 was significantly lower in the remdesivir group than in the supportive care group (22.9% vs. 44.7%, P = 0.032), and MV duration was significantly shorter in the remdesivir group (average, 1.97 vs. 5.37 days; P = 0.017). Analysis of upper respiratory tract specimens demonstrated that increases of Ct value from HD 1–5 to 11–15 were significantly greater in the remdesivir group than the supportive care group (average, 10.19 vs. 5.36; P = 0.007), and the slope of the Ct value increase was also significantly steeper in the remdesivir group (average, 5.10 vs. 2.68; P = 0.007).
Conclusion
The remdesivir group showed clinical and virologic benefit in terms of MV requirement and viral load reduction, supporting remdesivir treatment for severe COVID-19.