Publications by authors named "Shun Iida"
In the previously published version of the paper, the term "AS03" was used to describe the AddaS03 adjuvant used in animal experiments. This could lead to confusion among the trade and public as to a connection between the AddaS03 adjuvant and GSK's AS03. Upon request by GSK, the authors clarify that no AS03 from GSK was used in this study, and the results obtained with AddaS03 are not transposable to the GSK's AS03 adjuvant.
View Article and Find Full Text PDFMicrothrombus formation is associated with COVID-19 severity; however, the detailed mechanism remains unclear. In this study, we investigated mouse models with severe pneumonia caused by SARS-CoV-2 infection by using our in vivo two-photon imaging system. In the lungs of SARS-CoV-2-infected mice, increased expression of adhesion molecules in intravascular neutrophils prolonged adhesion time to the vessel wall, resulting in platelet aggregation and impaired lung perfusion.
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- A gastroscopy revealed multiple areas of erosion with white patches from the angulus (the bend of the stomach) to the antrum (the lower portion of the stomach).
- A gastric biopsy was taken and tested, showing numerous brown spirochetes, indicating an infection caused by syphilis.
- The findings suggest a significant gastrointestinal issue likely linked to an underlying syphilitic infection affecting the stomach.
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- Human adenovirus infection can be deadly for patients who have undergone allogeneic hematopoietic cell transplantation, but treatments like cidofovir only work for some cases.
- In a specific patient with immune issues and severe adenovirus infection post-transplant, there was notable T-cell reconstitution and reduction in virus levels after starting cidofovir, even with limited treatment due to kidney issues.
- The study suggests that improving transplantation techniques, using effective antiviral medications, and enhancing virus-specific T-cell therapies are key strategies to combat systemic adenovirus infections.
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.
View Article and Find Full Text PDFWe report a draft genome sequence of isolated from the spleen of a wild rat from Mikura-shima Island, Japan. The bacterium was identified as serotype O:4b using PCR-based O-genotyping. These genomic data provide insights into the pathogenic potential of this strain in spontaneous outbreaks among wild animals.
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- A study investigates the presence and infectiousness of SARS-CoV-2 in human corpses, finding high viral levels detected long after death.
- Nasopharyngeal swab samples from six deceased patients showed SARS-CoV-2 RNA, with one case still containing infectious virus 12 days postmortem.
- The findings suggest that the survival of infectious virus in corpses varies among individuals and may depend on the timing of death relative to the viral shedding phase.
During the Omicron wave, previous variants such as BA.2, BA.4, and BA.
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- - The study investigates the effectiveness of monotherapy with oral antiviral ensitrelvir and the anti-inflammatory corticosteroid methylprednisolone, as well as their combination, in treating hamsters infected with SARS-CoV-2, focusing on timing and therapeutic outcomes.
- - Results showed that combining ensitrelvir and methylprednisolone significantly improved respiratory health and decreased pneumonia risk, even when treatment started two days post-infection, by reducing lung damage and inflammation.
- - The findings underscore the potential benefits of using a combination therapy of antiviral and corticosteroid drugs for better lung pathology and inflammatory response management in COVID-19 cases, including those caused by the delta and omicron variants.
Infectious virus shedding from individuals infected with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is used to estimate human-to-human transmission risk. Control of SARS-CoV-2 transmission requires identifying the immune correlates that protect infectious virus shedding. Mucosal immunity prevents infection by SARS-CoV-2, which replicates in the respiratory epithelium and spreads rapidly to other hosts.
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- The study investigated the relationship between human herpesvirus-8 (HHV-8) and HIV-1 in patients, focusing on the presence of HHV-8 DNA in plasma and its association with certain diseases.
- Among 36 HIV-1 infected patients, 19 were diagnosed with Kaposi's sarcoma (KS), and findings revealed that higher levels of HHV-8 DNA correlated with other severe health issues like anemia and thrombocytopenia.
- After starting antiretroviral therapy (ART), the number of patients with detectable HHV-8 in their plasma significantly decreased, and there was an increase in anti-HHV-8 antibodies, suggesting that effective ART may help boost the immune response
The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a glycoprotein, expressed on the virion surface, that mediates infection of host cells by directly interacting with host receptors. As such, it is a reasonable target to neutralize the infectivity of the virus. Here we found that a recombinant S protein vaccine adjuvanted with Alhydrogel or the QS-21-like adjuvant Quil-A effectively induced anti-S receptor binding domain (RBD) serum IgG and neutralizing antibody titers in the Syrian hamster model, resulting in significantly low SARS-CoV-2 replication in respiratory organs and reduced body weight loss upon virus challenge.
View Article and Find Full Text PDFNumerous genomic analyses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been conducted, highlighting its variations and lineage transitions. Despite the importance of forensic autopsy in investigating deaths due to coronavirus disease 2019 (COVID-19), including out-of-hospital deaths, viral genomic analysis has rarely been reported due in part to postmortem changes. In this study, various specimens were collected from 18 forensic autopsy cases with SARS-CoV-2 infection.
View Article and Find Full Text PDFEnsitrelvir, 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.
View Article and Find Full Text PDFMinimally invasive autopsy (MIA) is an alternative to a full autopsy for the collection of tissue samples from patients' bodies using instruments such as a biopsy needle. MIA has been conducted in many cases of coronavirus disease 2019 (COVID-19) and has contributed to the elucidation of the disease pathogenesis. However, most cases analyzed are hospital deaths, and there are few reports on the application of MIA in out-of-hospital deaths with varying extents of post-mortem changes.
View Article and Find Full Text PDFThe 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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- A case-control study was conducted to assess COVID-19 infection risk among healthcare workers, collecting data on demographics, contact behaviors, and protective equipment usage.
- Out of 1,899 participants, 161 (8.5%) were found to be seropositive, with physical contact and aerosol-generating procedures significantly increasing risk.
- The use of goggles and N95 masks effectively reduced the risk of infection, and seroprevalence was notably higher in outbreak wards compared to COVID-19 dedicated wards.
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- COVID-19, caused by the virus SARS-CoV-2, remains a significant global health threat, with current treatments lacking sufficient effectiveness.
- Researchers have identified two new small molecules, TKB245 and TKB248, that effectively inhibit the main protease of SARS-CoV-2, showing greater potency against various strains compared to existing treatments.
- Both compounds demonstrate the ability to block replication of COVID-19 variants in lab models and bind to the virus's main protease, suggesting they could lead to the development of more effective COVID-19 treatments.
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- A study evaluated the impact of high-flow nasal cannula (HFNC) therapy on virus dispersion in critically ill COVID-19 patients, focusing on whether it aerosolizes the virus.
- Out of 17 patients, viral RNA was found in nasopharyngeal swabs, but no viable virus was detected in air samples close to the patients, regardless of the oxygen delivery method.
- The findings suggest that while viral RNA can be present in patients, HFNC therapy does not appear to disperse viable viruses into the air, indicating the need for further research under varying conditions.
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- The study assessed infectious SARS-CoV-2 levels in deceased COVID-19 patients to inform public health protocols.
- Researchers analyzed samples from 11 autopsy cases and found infectious virus present in 55% of the cases, with specific findings from both nasal swabs and lung tissue.
- Results indicate that the virus can remain infectious for up to 13 days postmortem, highlighting the need for strict infection control when handling these corpses.
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- Immune responses to SARS-CoV-2 variants are affected by prior infections and vaccinations, which can influence the effectiveness of booster shots.
- Higher viral loads and longer intervals between vaccination and infection lead to better neutralizing activity against variants like Omicron BA.4/5.
- Optimizing the timing of booster doses and designing targeted antigens are crucial for developing vaccines that can effectively combat diverse SARS-CoV-2 variants.
During the coronavirus disease 2019 (COVID-19) pandemic, autopsies have provided valuable insights into the pathogenesis of COVID-19. The precise effect of this pandemic on autopsy procedures in Japan, especially in instances unrelated to COVID-19, has not yet been established. Therefore, we conducted a questionnaire survey from December 2020 to January 2021 regarding the status of pathological autopsy practices in Japan during the first year of the COVID-19 pandemic.
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- - Plastic bronchitis (PB) is a rare respiratory disease that leads to airway obstruction due to mucus cast formation, with two main types: Type 1 caused by inflammation from allergies and Type 2 linked to congenital heart disease.
- - PB can be associated with viral infections, particularly the influenza A (H1N1) virus, but a case study highlighted severe Type 1 PB in a child due to human bocavirus (HBoV)1.
- - In this case, testing revealed other viruses like respiratory syncytial virus and human parainfluenza virus 3, but only HBoV1 was found in the mucus casts, suggesting HBoV's potential role in PB and the importance of thorough PCR testing
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- Oral antiviral agents, such as S-217622 (ensitrelvir), are being researched as effective treatments for COVID-19, alongside vaccination efforts.
- S-217622 specifically targets the main protease of SARS-CoV-2, demonstrating significant antiviral activity and reducing viral load in infected hamsters.
- This antiviral agent shows promise against various strains of the virus and is currently undergoing evaluation in a phase 3 clinical trial, highlighting its potential as an oral therapeutic option for COVID-19.