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1.
NPG Asia Materials ; 15(1):17, 2023.
Article in English | ProQuest Central | ID: covidwho-2277200

ABSTRACT

To efficiently combat viral infectious diseases, it is important to develop broadly applicable countermeasures, and efficient antiviral systems can be developed by elaborating the relationship of antiviral efficiency with the interactions between antiviral agents and viruses. In the present study, conjugated polymer (CP)-based photodynamic therapy was used to inhibit RNA virus infections. A severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudotyped virus composed of an SARS-CoV-2 envelope coated with the S protein and luciferase RNA genome was employed to assess antiviral efficiency. Three cationic CPs with different backbone structures, fluorene-co-phenylene (PFP), thiophene (PMNT), and phenylene vinylene (PPV), exhibit different photoinactivation effects. The highly efficient photoinactivation of PPV and PMNT is derived from the complete photodegradation of spike proteins, nucleocapsid proteins and nucleic acids of SARS-CoV-2 after binding to the viral spike proteins. Although PFP showed the highest efficiency in the photodegradation of spike proteins due to its strong binding affinity, ineffective viral inhibition was observed, which occurred because the viral gene was partially damaged under light irradiation and the process of delivering the viral gene to cells received assistance. This work preliminarily reveals the effect of CP-virus interactions on their photoinactivation activity and should be beneficial for further research on the development of highly efficient antiviral PDT agents.In this work, a photodynamic therapy system based on conjugated polymers (CPs) is developed to inhibit the infection of RNA viruses. Three cationic CPs with different backbone structures fluorene-co-phenylene (PFP), thiophene (PMNT), and phenylene vinylene (PPV) exhibit different photoinactivation effects. PPV and PMNT cause effective inactivation of viruses under light irradiation, while SARS-CoV-2 pseudotyped viruses keep infectious after treated by PFP, which is determined by the interactions between CPs with the proteins and gene of viruses. This work preliminarily reveals the effect of CP-virus interactions on their photoinactivation activity and would be beneficial to develop high-efficient antiviral PDT agents.

2.
Int J Public Health ; 67: 1605505, 2022.
Article in English | MEDLINE | ID: covidwho-2286910

ABSTRACT

Objectives: To examine the level of resilience among the frontline healthcare workers (HCWs) in four different Southeast Asian jurisdictions and identify the potential factors that may enhance healthcare workers resilience. Methods: An online cross-sectional survey was carried out among 3,048 eligible healthcare workers in Hong Kong, Nepal, Vietnam, and Taiwan from May 2021 to July 2022, and information on individual resilience, socio-demographic characteristics, organizational supports, and personal exposures were collected. A binary logistic regression model was used to identify the factors that were associated with a high resilience level. Results: The resilience score was the highest among healthcare workers of Vietnam, followed by Taiwan and Hong Kong, with Nepal scoring the lowest. Participants with old age, part-time work, higher education level, more satisfaction with workplace policy, better organizational supports, and fewer COVID-specific worries were associated with higher resilience. Healthcare workers who were satisfied with the overall organizational policy support had an OR of 1.48 (95% CI: 1.25-1.76) for a high resilience level. Conclusion: Implementing satisfying organizational policies and establishing supportive work environments for frontline healthcare workers can increase individual resilience and organizational stability.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Cross-Sectional Studies , Health Personnel , Pandemics , Asia, Southeastern
3.
ACS Biomater Sci Eng ; 9(4): 1891-1899, 2023 04 10.
Article in English | MEDLINE | ID: covidwho-2256024

ABSTRACT

Bioinspired bactericidal surfaces are artificial surfaces that mimic the nanotopography of insect wings and are capable of inhibiting microbial growth by a physicomechanical mechanism. The scientific community has considered them an alternative method to design polymers with surfaces that inhibit bacterial biofilm formation, suitable for self-disinfectant medical devices. In this contribution, poly(lactic acid) (PLA) with nanocone patterns was successfully produced by a novel two-step procedure involving copper plasma deposition followed by argon plasma etching. According to reverse transcription-quantitative polymerase chain reaction tests, the bioinspired PLA nanostructures display antiviral performance to inactivate infectious Omicron severe acute respiratory syndrome coronavirus 2 particles, reducing the amount of the viral genome to less than 4% in just 15 min due to a possible combined effect of mechanical and oxidative stress. The bioinspired antiviral PLA can be suitable for designing personal protection equipment to prevent the transmission of contagious viral diseases, such as Coronavirus Disease 2019.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Anti-Bacterial Agents/pharmacology , Antiviral Agents/pharmacology , Polyesters
4.
J Infect Dis ; 2023 Apr 03.
Article in English | MEDLINE | ID: covidwho-2283518

ABSTRACT

BACKGROUND: China has been using inactivated COVID-19 vaccines as primary series and booster doses to protect the population from severe to fatal COVID-19. We evaluated primary and booster vaccine effectiveness (VE) against Omicron BA.2 infection outcomes. METHODS: This was a 13-province retrospective cohort study of quarantined close contacts of BA.2-infected individuals. Outcomes were BA.2 infection, COVID-19 pneumonia or worse, and severe/critical COVID-19. Absolute VE was estimated by comparison with an unvaccinated group. RESULTS: There were 289,427 close-contacts ≥3 years old exposed to Omicron BA.2 cases; 31,831 turned nucleic-acid amplification test (NAAT)-positive during quarantine, 97.2% with mild or asymptomatic infection, 2.6% had COVID-19 pneumonia, and 0.15% had severe/critical COVID-19. None died. Adjusted VE against any infection was 17% for primary series and 22% when boosted. Primary series aVE in adults >18 years was 66% against pneumonia or worse infection and 91% against severe/critical COVID-19. Booster dose aVE was 74% against pneumonia or worse, and 93% against severe/critical COVID-19. CONCLUSIONS: Inactivated COVID-19 vaccines provided modest protection from infection, very good protection against pneumonia, and excellent protection against severe/critical COVID-19. Booster doses are necessary to provide strongest protection.

5.
Adv Mater ; 35(19): e2210936, 2023 May.
Article in English | MEDLINE | ID: covidwho-2281064

ABSTRACT

Antimicrobial agents are massively used to disinfect the pathogen contaminated surfaces since the Corona Virus Disease 2019 (COVID-19) outbreak. However, their defects of poor durability, strong irritation, and high environmental accumulation are exposed. Herein, a convenient strategy is developed to fabricate long-lasting and target-selective antimicrobial agent with the special hierarchical structure through bottom-up assembly of natural gallic acid with arginine surfactant. The assembly starts from rodlike micelles, further stacking into hexagonal columns and finally interpenetrating into spherical assemblies, which avoid explosive release of antimicrobial units. The assemblies show anti-water washing and high adhesion on various surfaces; and thus, possess highly efficient and broad-spectrum antimicrobial activities even after using up to eleven cycles. Both in vitro and in vivo experiments prove that the assemblies are highly selective in killing pathogens without generating toxicity. The excellent antimicrobial virtues well satisfy the increasing anti-infection demands and the hierarchical assembly exhibits great potential as a clinical candidate.


Subject(s)
Anti-Infective Agents , COVID-19 , Surface-Active Agents , Arginine , Polyphenols/pharmacology , Anti-Infective Agents/pharmacology , Plants
6.
Int J Environ Res Public Health ; 20(1)2022 12 25.
Article in English | MEDLINE | ID: covidwho-2246213

ABSTRACT

The purpose of this study is to evaluate patient complaints using the Healthcare Complaints Analysis Tool (HCAT) during the COVID-19 pandemic in 2021 in Taiwan. Additionally, the study examines the distribution and type of patient complaints before and during the COVID-19 pandemic to provide a better clinical procedure, hospital management and patient relationship. This study utilizes a cross-sectional design. We collected patient complaints from January 2021 to December 2021 at a medical center in Southern Taiwan. Using the Healthcare Complaints Analysis Tool (HCAT), the patient complaints are classified and coded into three major domains (clinical, management and relationship), and seven problem categories (quality, safety, environment, institutional process, respect and patient rights, listening and communication). We further compared and categorized the complaints based on whether they were COVID-19-related or not and whether it was before or during the COVID-19 pandemic to understand the differences in patient complaints. In total, we collected 584 events of patient complaints. Based on the HCAT domains, the complaints about management were the highest, at 52.9%, followed by complaints about relationship, about 37.7%. According to the types of problem, the complaints about the environment were the highest, about 32.5% (190/584), followed by communication at about 29.6% (173/584), and institutional process at about 20.4% (119/584). There were 178 COVID-19-related complaints and they were made more frequently during Q3 and Q4 (from mid-June to December) which was the pandemic period in 2021 in Taiwan. Among the COVID-19-related complaints, the most frequent were in the environment domain with 114 cases (about 65.7% of COVID-19-related complaints). The domains of patient complaints were statistically different between COVID-19-related and non-related (p < 0.001). During the COVID-19 pandemic, the proportion of COVID-19-related complaints increased 1.67 times (117/312 vs. 61/272, p < 0.001). Both prior to and during the COVID-19 pandemic, management-related complaints represented the highest domain. During the COVID-19 pandemic, the implementation of infectious disease prevention and control policies and actions may have developed some inconvenience and difficulty in seeking medical practice and process. These characteristics (complaints) are more prominent, and timely and patient-first consideration is required immediately to build up better clinical procedures, the healthcare environment and comprehensive communication. Using the HCAT can allow health centers or health practitioners to understand the needs and demands of patients through complaints, provide friendly medical and health services, avoid unequal information transmission, build trust in doctor−patient relationships and improve patients' safety.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Pandemics , Taiwan/epidemiology , Cross-Sectional Studies , Hospitals , Patient Satisfaction
7.
Arch Psychiatr Nurs ; 42: 40-44, 2023 02.
Article in English | MEDLINE | ID: covidwho-2239691

ABSTRACT

STUDY OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has resulted in major disruption to regular learning and training for medical staff. The aim of this study was to compare the learning efficacy between on-site training before the COVID-19 pandemic and online training during the pandemic for nurses, psychologists, social workers, and occupational therapists from Southeast Asia. METHOD: The current study derived data from the International Mental Health Training Center Taiwan (IMHTCT) from 2018 to 2020. IMHTCT Trainees Learning Effect Questionnaire (ITLEQ) scores of the medical staff and demographic variables were collected. Reliability and validity of the ITLEQ were estimated. The independent t-test was used to compare differences in ITLEQ scores between the pre-training and post-training stages among the trainees. In addition, generalized estimating equations were used to estimate the predictive effect of online training on changes in ITLEQ scores over time. FINDINGS: A total of 190 trainees were enrolled, including 92 social workers, 16 occupation therapists, 24 psychologists, and 58 nurses. The reliability and validity were satisfactory. The efficacy of the training programs at IMHTCT was significant for all of the healthcare workers. Furthermore, better training efficacy was found in the social workers and occupational therapists who received online training compared to those who received on-site training. The potential efficacy of online training was found in the nurses. CONCLUSION: Our results demonstrate the importance of online training for mental healthcare workers during the COVID-19 pandemic. Online training may be implemented into regular training courses in the future.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Pandemics , SARS-CoV-2 , Mental Health , Taiwan , Reproducibility of Results , Health Personnel/psychology
8.
Int J Environ Res Public Health ; 20(4)2023 Feb 09.
Article in English | MEDLINE | ID: covidwho-2236767

ABSTRACT

The COVID-19 outbreak at the end of December 2019 spread rapidly all around the world. The objective of this study is to investigate and understand the relationship between public health measures and the development of the pandemic through Google search behaviors in the United States. Our collected data includes Google search queries related to COVID-19 from 1 January to 4 April 2020. After using unit root tests (ADF test and PP test) to examine the stationary and a Hausman test to choose a random effect model, a panel data analysis is conducted to investigate the key query terms with the newly added cases. In addition, a full sample regression and two sub-sample regressions are proposed to explain: (1) The changes in COVID-19 cases number are partly related to search variables related to treatments and medical resources, such as ventilators, hospitals, and masks, which correlate positively with the number of new cases. In contrast, regarding public health measures, social distancing, lockdown, stay-at-home, and self-isolation measures were negatively associated with the number of new cases in the US. (2) In mild states, which ranked one to twenty by the average daily new cases from least to most in 50 states, the query terms about public health measures (quarantine, lockdown, and self-isolation) have a significant negative correlation with the number of new cases. However, only the query terms about lockdown and self-isolation are also negatively associated with the number of new cases in serious states (states ranking 31 to 50). Furthermore, public health measures taken by the government during the COVID-19 outbreak are closely related to the situation of controlling the pandemic.


Subject(s)
COVID-19 , Health Communication , Humans , United States , Search Engine , Communicable Disease Control , Quarantine
9.
Acta Pharmacol Sin ; 44(7): 1455-1463, 2023 Jul.
Article in English | MEDLINE | ID: covidwho-2221797

ABSTRACT

The continuous emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants poses challenges to the effectiveness of neutralizing antibodies. Rational design of antibody cocktails is a realizable approach addressing viral immune evasion. However, evaluating the breadth of antibody cocktails is essential for understanding the development potential. Here, based on a replication competent vesicular stomatitis virus model that incorporates the spike of SARS-CoV-2 (VSV-SARS-CoV-2), we evaluated the breadth of a number of antibody cocktails consisting of monoclonal antibodies and bispecific antibodies by long-term passaging the virus in the presence of the cocktails. Results from over two-month passaging of the virus showed that 9E12 + 10D4 + 2G1 and 7B9-9D11 + 2G1 from these cocktails were highly resistant to random mutation, and there was no breakthrough after 30 rounds of passaging. As a control, antibody REGN10933 was broken through in the third passage. Next generation sequencing was performed and several critical mutations related to viral evasion were identified. These mutations caused a decrease in neutralization efficiency, but the reduced replication rate and ACE2 susceptibility of the mutant virus suggested that they might not have the potential to become epidemic strains. The 9E12 + 10D4 + 2G1 and 7B9-9D11 + 2G1 cocktails that picked from the VSV-SARS-CoV-2 system efficiently neutralized all current variants of concern and variants of interest including the most recent variants Delta and Omicron, as well as SARS-CoV-1. Our results highlight the feasibility of using the VSV-SARS-CoV-2 system to develop SARS-CoV-2 antibody cocktails and provide a reference for the clinical selection of therapeutic strategies to address the mutational escape of SARS-CoV-2.


Subject(s)
Antibodies, Bispecific , COVID-19 , Humans , SARS-CoV-2 , Combined Antibody Therapeutics , Neutralization Tests , Antibodies, Bispecific/therapeutic use , Antibodies, Neutralizing
10.
China Tropical Medicine ; 22(12):1184-1187, 2022.
Article in Chinese | GIM | ID: covidwho-2203861

ABSTRACT

Objective: To analyze the detection of SARS-CoV-2 in household environment and public place environment of Huangpu District, and describe the feature of SARS-CoV-2 contamination in the environment exposure to the infected cases, so as to support the control strategies such as disinfection and health communication.

11.
International journal of public health ; 67, 2022.
Article in English | EuropePMC | ID: covidwho-2170140

ABSTRACT

Objectives: To examine the level of resilience among the frontline healthcare workers (HCWs) in four different Southeast Asian jurisdictions and identify the potential factors that may enhance healthcare workers resilience. Methods: An online cross-sectional survey was carried out among 3,048 eligible healthcare workers in Hong Kong, Nepal, Vietnam, and Taiwan from May 2021 to July 2022, and information on individual resilience, socio-demographic characteristics, organizational supports, and personal exposures were collected. A binary logistic regression model was used to identify the factors that were associated with a high resilience level. Results: The resilience score was the highest among healthcare workers of Vietnam, followed by Taiwan and Hong Kong, with Nepal scoring the lowest. Participants with old age, part-time work, higher education level, more satisfaction with workplace policy, better organizational supports, and fewer COVID-specific worries were associated with higher resilience. Healthcare workers who were satisfied with the overall organizational policy support had an OR of 1.48 (95% CI: 1.25–1.76) for a high resilience level. Conclusion: Implementing satisfying organizational policies and establishing supportive work environments for frontline healthcare workers can increase individual resilience and organizational stability.

12.
J Med Virol ; 95(2): e28478, 2023 02.
Article in English | MEDLINE | ID: covidwho-2173236

ABSTRACT

Patients with severe COVID-19 often suffer from lymphopenia, which is linked to T-cell sequestration, cytokine storm, and mortality. However, it remains largely unknown how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces lymphopenia. Here, we studied the transcriptomic profile and epigenomic alterations involved in cytokine production by SARS-CoV-2-infected cells. We adopted a reverse time-order gene coexpression network approach to analyze time-series RNA-sequencing data, revealing epigenetic modifications at the late stage of viral egress. Furthermore, we identified SARS-CoV-2-activated nuclear factor-κB (NF-κB) and interferon regulatory factor 1 (IRF1) pathways contributing to viral infection and COVID-19 severity through epigenetic analysis of H3K4me3 chromatin immunoprecipitation sequencing. Cross-referencing our transcriptomic and epigenomic data sets revealed that coupling NF-κB and IRF1 pathways mediate programmed death ligand-1 (PD-L1) immunosuppressive programs. Interestingly, we observed higher PD-L1 expression in Omicron-infected cells than SARS-CoV-2 infected cells. Blocking PD-L1 at an early stage of virally-infected AAV-hACE2 mice significantly recovered lymphocyte counts and lowered inflammatory cytokine levels. Our findings indicate that targeting the SARS-CoV-2-mediated NF-κB and IRF1-PD-L1 axis may represent an alternative strategy to reduce COVID-19 severity.


Subject(s)
COVID-19 , Lymphopenia , Animals , Mice , SARS-CoV-2/metabolism , B7-H1 Antigen , Immune Evasion , NF-kappa B/metabolism , Up-Regulation , Cytokines/metabolism
13.
BMC Public Health ; 22(1): 2339, 2022 12 13.
Article in English | MEDLINE | ID: covidwho-2162338

ABSTRACT

BACKGROUND: The spread of unvetted scientific information about COVID-19 presents a significant challenge to public health, adding to the urgency for increased understanding of COVID-19 information-seeking preferences that will allow for the delivery of evidence-based health communication. This study examined factors associated with COVID-19 information-seeking behavior. METHODS: An online survey was conducted with US adults (N = 1800) to identify key interpersonal (e.g., friends, health care providers) and mediated (e.g., TV, social media) sources of COVID-19 information. Logistic regression models were fitted to explore correlates of information-seeking. RESULTS: Study findings show that the first sought and most trusted sources of COVID-19 information had different relationships with sociodemographic characteristics, perceived discrimination, and self-efficacy. Older adults had greater odds of seeking information from print materials (e.g., newspapers and magazines) and TV first. Participants with less educational attainment and greater self-efficacy preferred interpersonal sources first, with notably less preference for mass media compared to health care providers. Those with more experiences with discrimination were more likely to seek information from friends, relatives, and co-workers. Additionally, greater self-efficacy was related to increased trust in interpersonal sources. CONCLUSION: Study results have implications for tailoring health communication strategies to reach specific subgroups, including those more vulnerable to severe illness from COVID-19. A set of recommendations are provided to assist in campaign development.


Subject(s)
COVID-19 , Health Communication , Humans , Aged , Pandemics , COVID-19/epidemiology , Infodemic , Information Seeking Behavior , Surveys and Questionnaires
14.
Journal of Agricultural Big Data ; 4(1):69-76, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2145868

ABSTRACT

In 2020, the COVID-19 pandemic broke out globally, and cold-chain food has become the key point of the task to prevent the coronavirus from spreading within the city/region or beyond. Using information tools like establishing a national cold-chain traceability management platform to control the risk of imported cold-chain food has become an important topic at present. The paper focuses on the technology used by provinces and cities in cold-chain traceability, and combined with the actual needs, analyzes the advantages of heterogeneous identification technology. This paper starts from the present situation, introducing the technical roadmap selecting of traceability of imported cold-chain food and elaborating the data circulation structure of traceability of imported cold-chain food. Based on that, this paper introduces the national traceability platform of imported cold-chain food and its core functions based on heterogeneous identification. Through the construction of a three-level framework with the national cold-chain traceability management platform, to make sure the cold chain food can be traceable and be manageable. Meanwhile, through the two applications of inter-provincial confirmation and data verification, the national management effect of imported cold chain food is improved. [Outlook] Currently, the platform mainly focuses on imported livestock, poultry and aquatic products. In the future, the traceability scope may be gradually expanded to help improve the management effect. Establishing the imported cold-chain food traceability platform has a good effect on improving the information management level and promoting the traceability efficiency of problematic food, which is conducive to ensuring food safety.

15.
The Pan African medical journal ; 43, 2022.
Article in English | EuropePMC | ID: covidwho-2126218

ABSTRACT

Rapid scale-up of surveillance activities is the key to successful coronavirus disease 2019 (COVID-19) pandemic prevention and mitigation. Ethiopia did not have a sufficient number of active surveillance officers for the public health COVID-19 response. Training of surveillance officers was needed urgently to fill the gap in the workforce needed. Subject-matter experts from the United States and Ethiopia developed applicable training modules including background on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), contact investigation, and communications. The training modules were delivered live in real-time via web-based virtual presentation. Seventy-seven health surveillance officers were hired, trained, and deployed in two weeks to assist with surveillance activities in Ethiopia. Electronic capacity building is needed in order to improve Web-based training in resource-limited settings where internet access is limited or unreliable. Web-based synchronously delivered course was an effective platform for COVID-19 surveillance training. However, strengthening public and private information technology capacity, literacy, and internet availability will improve Web-based education platforms in resource-limited countries.

16.
Front Public Health ; 10: 1021200, 2022.
Article in English | MEDLINE | ID: covidwho-2142353

ABSTRACT

We report a severe COVID-19 complicated with MIS-C in a girl treated by the author in China, and discuss the current research status and progress in the diagnosis and therapy of MIS-C in children. The patient was a 4-year-old child previously healthy who was referred to the hospital with a complaint of fever, finally, Multisystem inflammatory syndrome was diagnosed with COVID-19.


Subject(s)
COVID-19 , SARS-CoV-2 , Female , Humans , Child, Preschool , China
17.
Front Public Health ; 10: 1008348, 2022.
Article in English | MEDLINE | ID: covidwho-2142342

ABSTRACT

Examining stock market interactions between China (mainland China and Hong Kong), Japan, and South Korea, this study employs a framework that includes 239 economic variables to identify the spillover effects among these three countries, and empirically simulates the dynamic time-varying non-linear relationship between the stock markets of different countries. The findings are that in recent decades, China's stock market relied on Hong Kong's as a window to the exchange of price information with Japan and South Korea. More recently, the China stock market's spillover effect on East Asia has expanded. The spread of the crisis has strengthened co-movement between the stock markets of China, Japan, and South Korea.


Subject(s)
COVID-19 , Humans , Japan , COVID-19/epidemiology , Republic of Korea , China , Asia, Eastern
18.
Pan Afr Med J ; 43: 23, 2022.
Article in English | MEDLINE | ID: covidwho-2067226

ABSTRACT

Rapid scale-up of surveillance activities is the key to successful coronavirus disease 2019 (COVID-19) pandemic prevention and mitigation. Ethiopia did not have a sufficient number of active surveillance officers for the public health COVID-19 response. Training of surveillance officers was needed urgently to fill the gap in the workforce needed. Subject-matter experts from the United States and Ethiopia developed applicable training modules including background on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), contact investigation, and communications. The training modules were delivered live in real-time via web-based virtual presentation. Seventy-seven health surveillance officers were hired, trained, and deployed in two weeks to assist with surveillance activities in Ethiopia. Electronic capacity building is needed in order to improve Web-based training in resource-limited settings where internet access is limited or unreliable. Web-based synchronously delivered course was an effective platform for COVID-19 surveillance training. However, strengthening public and private information technology capacity, literacy, and internet availability will improve Web-based education platforms in resource-limited countries.


Subject(s)
COVID-19 , Humans , SARS-CoV-2 , Ethiopia , Contact Tracing , Pandemics
19.
J Biol Chem ; 298(11): 102511, 2022 11.
Article in English | MEDLINE | ID: covidwho-2031421

ABSTRACT

Revealing the mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry and cell-to-cell spread might provide insights for understanding the underlying mechanisms of viral pathogenesis, tropism, and virulence. The signaling pathways involved in SARS-CoV-2 entry and viral spike-mediated cell-to-cell fusion remain elusive. In the current study, we found that macropinocytosis inhibitors significantly suppressed SARS-CoV-2 infection at both the entry and viral spike-mediated cell-to-cell fusion steps. We demonstrated that SARS-CoV-2 entry required the small GTPase Rac1 and its effector kinase p21-activated kinase 1 by dominant-negative and RNAi assays in human embryonic kidney 293T-angiotensin-converting enzyme 2 cells and that the serine protease transmembrane serine protease 2 reversed the decrease in SARS-CoV-2 entry caused by the macropinocytosis inhibitors. Moreover, in the cell-to-cell fusion assay, we confirmed that macropinocytosis inhibitors significantly decreased viral spike-mediated cell-to-cell fusion. Overall, we provided evidence that SARS-CoV-2 utilizes a macropinocytosis pathway to enter target cells and to efficiently promote viral spike-mediated cell-to-cell fusion.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Spike Glycoprotein, Coronavirus/metabolism , Cell Fusion , Virus Internalization , Serine Proteases
20.
Mater Today Commun ; 33: 104288, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1996445

ABSTRACT

The current pandemic of Coronavirus Disease 2019 (COVID-19) raised several concerns about using conventional textiles for manufacturing personal protective equipment without self-disinfecting properties since the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is transmitted mainly by aerosols that can transpose cotton masks. Therefore, developing new cotton fibers with high self-disinfecting ability is essential to avoid a new pandemic due to new SARS-CoV-2 variants. Herein, we developed cotton wipes (CFs) with fibers coated by Ag, TiO2, and Ag/TiO2 hybrid nanoparticles like Brazilian heavy-fruited Myrciaria cauliflora by a sonochemical approach. Moreover, the coated CFs present high antimicrobial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), being able to inactivate infectious SARS-CoV-2 (Delta variant) by the destruction of the spike, membrane, and nucleocapsid proteins while the viral RNA is not significantly affected, according to the molecular biological findings.

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