Publications by authors named "Yuri Furusawa"

Aim: The present study assessed low-density lipoprotein cholesterol (LDL-C) levels in school-aged children from the Ogasa District of Shizuoka Prefecture and evaluated the utility of non-invasive vascular tests, namely flow-mediated dilation (FMD) and intima-media thickness (IMT), in pediatric patients with familial hypercholesterolemia (FH).

Method: We analyzed the lipid test results of 8,568 students screened for prevention of lifestyle-related diseases and 78 children under 15 years old with cholesterol levels exceeding 220 mg/dL who visited Chutoen General Medical Center. We examined the LDL-C distribution from school-age screenings and conducted FMD and IMT assessments on those meeting the 2022 Pediatric FH Guidelines criteria.

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We generated SARS-CoV-2 variants resistant to three SARS-CoV-2 main protease (M) inhibitors (nirmatrelvir, TKB245, and 5h), by propagating the ancestral SARS-CoV-2 in VeroE6 cells with increasing concentrations of each inhibitor and examined their structural and virologic profiles. A predominant E166V-carrying variant (SARS-CoV-2), which emerged when passaged with nirmatrelvir and TKB245, proved to be resistant to the two inhibitors. A recombinant SARS-CoV-2 was resistant to nirmatrelvir and TKB245, but sensitive to 5h.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) often causes severe viral pneumonia. Although many studies using mouse models have examined the pathogenicity of SARS-CoV-2, COVID-19 pathogenesis remains poorly understood. In vivo imaging analysis using two-photon excitation microscopy (TPEM) is useful for elucidating the pathology of COVID-19, providing pathological insights that are not available from conventional histological analysis.

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Ensitrelvir, an oral antiviral agent that targets a SARS-CoV-2 main protease (3CLpro or Nsp5), is clinically useful against SARS-CoV-2 including its omicron variants. Since most omicron subvariants have reduced sensitivity to most monoclonal antibody therapies, SARS-CoV-2 resistance to other antivirals including main protease inhibitors such as ensitrelvir is a major public health concern. Here, repeating passages of SARS-CoV-2 in the presence of ensitrelvir revealed that the M49L and E166A substitutions in Nsp5 are responsible for reduced sensitivity to ensitrelvir.

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SARS-CoV-2 has gradually acquired amino acid substitutions in its S protein that reduce the potency of neutralizing antibodies, leading to decreased vaccine efficacy. Here, we attempted to obtain mutant viruses by passaging SARS-CoV-2 in the presence of plasma samples from convalescent patients or vaccinees to determine which amino acid substitutions affect the antigenicity of SARS-CoV-2. Several amino acid substitutions in the S2 region, as well as the N-terminal domain (NTD) and receptor-binding domain (RBD), affected the neutralization potency of plasma samples collected from vaccinees, indicating that amino acid substitutions in the S2 region as well as those in the NTD and RBD affect neutralization by vaccine-induced antibodies.

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Nirmatrelvir, an oral antiviral agent that targets a SARS-CoV-2 main protease (3CLpro), is clinically useful against infection with SARS-CoV-2 including its omicron variants. Since most omicron subvariants have reduced sensitivity to many monoclonal antibody therapies, potential SARS-CoV-2 resistance to nirmatrelvir is a major public health concern. Several amino acid substitutions have been identified as being responsible for reduced susceptibility to nirmatrelvir.

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Article Synopsis
  • - Several antibody therapeutics exist for SARS-CoV-2, but their effectiveness has decreased against emerging variants, prompting researchers to explore new antibodies obtained from recovered COVID-19 patients' B cells.
  • - From 172 antibodies created using the Wuhan strain and Gamma variant, six were effective against earlier strains, while five showed some ability to combat Omicron sub-strains, indicating a potential for broader neutralization.
  • - Testing one promising antibody in hamsters showed a significant reduction in lung viral levels, demonstrating its potential as an antiviral treatment and underscoring the need for effective initial screening in developing such therapies.
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The prevalence of the Omicron subvariant BA.2.75 rapidly increased in India and Nepal during the summer of 2022, and spread globally.

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Background: Reverse genetics systems to rescue viruses from modified DNA are useful tools to investigate the molecular mechanisms of viruses. The COVID-19 pandemic prompted the development of several reverse genetics systems for SARS-CoV-2. The circular polymerase extension reaction (CPER) method enables the rapid generation of recombinant SARS-CoV-2; however, such PCR-based approaches could introduce unwanted mutations due to PCR errors.

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Article Synopsis
  • Researchers developed 494 monoclonal antibodies from COVID-19 convalescent patients and found some that effectively neutralize SARS-CoV-2, including its variants, similar to existing clinical antibodies.
  • The antibodies demonstrated varied effectiveness against different virus mutations and were validated through cell-based assays and cryo-electron microscopy.
  • Therapeutic tests in hamster and macaque models showed that these antibodies, especially in a cocktail form, significantly reduced viral levels and lung damage, indicating their potential as therapeutic options against COVID-19.
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The BA.2 sublineage of the SARS-CoV-2 Omicron variant has become dominant in most countries around the world; however, the prevalence of BA.4 and BA.

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The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the major antigen stimulating the host's protective immune response. Here we assessed the efficacy of therapeutic monoclonal antibodies (mAbs) against Omicron variant (B.1.

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Article Synopsis
  • The emergence of the Omicron variant BA.2 has heightened worries about the reduced effectiveness of current COVID-19 vaccines and treatments due to its mutations, with BA.2 now dominant in many countries.
  • Research comparing the infectivity and pathogenicity of BA.2 to BA.1 in mice and hamsters found that both variants exhibit similar levels of infectivity but are less pathogenic than earlier SARS-CoV-2 strains.
  • Despite a significant decrease in neutralizing antibody response from COVID-19 survivors and vaccine recipients against BA.2, some therapeutic monoclonal antibodies and antiviral drugs still show effectiveness in treating BA.2 infections in hamsters.
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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (COVID-19) is an acute respiratory infection transmitted by droplets, aerosols, and contact. Controlling the spread of COVID-19 and developing effective decontamination options are urgent issues for the international community. Here, we report the quantitative inactivation of SARS-CoV-2 in liquid and aerosolized samples by a state-of-the-art, high-power, AlGaN-based, single-chip compact deep-UV (DUV) light-emitting diode (LED) that produces a record continuous-wave output power of 500 mW at its peak emission wavelength of 265 nm.

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The recent emergence of SARS-CoV-2 Omicron variants possessing large numbers of mutations has raised concerns of decreased effectiveness of current vaccines, therapeutic monoclonal antibodies, and antiviral drugs for COVID-19 against these variants1,2. While the original Omicron lineage, BA.1, has become dominant in many countries, BA.

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Article Synopsis
  • The spike protein of SARS-CoV-2 is crucial for the virus's ability to infect hosts and trigger immune responses, particularly the production of antibodies.
  • A new variant called P.1, identified in Brazil, was studied in hamsters to assess its virulence and ability to evade immune responses compared to earlier strains.
  • Results showed that while P.1 replicates similarly to earlier strains, it may be antigenically distinct, as antibodies from previous infections were less effective against it, suggesting potential implications for vaccine efficacy.
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Introduction: Rapid antigen detection (RAD) tests are convenient tools for detecting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in clinics, and testing using saliva samples could decrease the risk of infection during sample collection. This study aimed to assess the accuracy of the SARS-CoV-2 RAD for testing of nasopharyngeal swab specimens and saliva samples in comparison with the RT-PCR tests and viral culture for detecting viable virus.

Methods: One hundred seventeen nasopharyngeal swab specimens and 73 saliva samples with positive results on RT-PCR were used.

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Reverse transcription-quantitative PCR (RT-qPCR)-based tests are widely used to diagnose coronavirus disease 2019 (COVID-19). As a result that these tests cannot be done in local clinics where RT-qPCR testing capability is lacking, rapid antigen tests (RATs) for COVID-19 based on lateral flow immunoassays are used for rapid diagnosis. However, their sensitivity compared with each other and with RT-qPCR and infectious virus isolation has not been examined.

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Guidelines from the CDC and the WHO recommend the wearing of face masks to prevent the spread of coronavirus (CoV) disease 2019 (COVID-19); however, the protective efficiency of such masks against airborne transmission of infectious severe acute respiratory syndrome CoV-2 (SARS-CoV-2) droplets/aerosols is unknown. Here, we developed an airborne transmission simulator of infectious SARS-CoV-2-containing droplets/aerosols produced by human respiration and coughs and assessed the transmissibility of the infectious droplets/aerosols and the ability of various types of face masks to block the transmission. We found that cotton masks, surgical masks, and N95 masks all have a protective effect with respect to the transmission of infective droplets/aerosols of SARS-CoV-2 and that the protective efficiency was higher when masks were worn by a virus spreader.

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At the end of 2019, a novel coronavirus (severe acute respiratory syndrome coronavirus 2; SARS-CoV-2) was detected in Wuhan, China, that spread rapidly around the world, with severe consequences for human health and the global economy. Here, we assessed the replicative ability and pathogenesis of SARS-CoV-2 isolates in Syrian hamsters. SARS-CoV-2 isolates replicated efficiently in the lungs of hamsters, causing severe pathological lung lesions following intranasal infection.

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