Publications by authors named "Terumasa Ikeda"
Poncet disease (PD) is a rare form of reactive polyarthritis associated with acute tuberculosis (TB). Multiple TB foci are rare in PD, particularly on the hands. Herein, we describe a case of PD with foci in the trapezium and spine of a 76-year-old man.
View Article and Find Full Text PDFBackground: Emergence of SARS-CoV-2 variants that escape neutralising antibodies hampers the development of vaccines and therapeutic antibodies against SARS-CoV-2. IGHV3-53/3-66-derived public antibodies, which are generally specific to the prototype virus and are frequently induced in infected or vaccinated individuals, show minimal affinity maturation and high potency against prototype SARS-CoV-2.
Methods: Monoclonal antibodies isolated from a Delta breakthrough infection case were analysed for cross-neutralising activities against SARS-CoV-2 variants.
The introduction of combined antiretroviral therapy (cART) has greatly improved the quality of life of human immunodeficiency virus type 1 (HIV-1)-infected individuals. Nonetheless, the ever-present desire to seek out a full remedy for HIV-1 infections makes the discovery of novel antiviral medication compelling. Owing to this, a new late-stage inhibitor, Lenacapavir/Sunlenca, an HIV multi-phase suppressor, was clinically authorized in 2022.
View Article and Find Full Text PDFSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has acquired multiple mutations since its emergence. Analyses of the SARS-CoV-2 genomes from infected patients exhibit a bias toward C-to-U mutations, which are suggested to be caused by the apolipoprotein B mRNA editing enzyme polypeptide-like 3 (APOBEC3, A3) cytosine deaminase proteins. However, the role of A3 enzymes in SARS-CoV-2 replication remains unclear.
View Article and Find Full Text PDFArticle Synopsis
- A new variant of SARS-CoV-2, called EG.5.1, is spreading rapidly and has been studied using various scientific methods to understand its features.
- Key mutations in EG.5.1, specifically S:F456L and ORF9b:I5T, enhance its viral fitness compared to other variants like XBB.1.5.
- Structural differences were found in the spike proteins of EG.5.1 versus XBB.1.5, and the research helps us understand the evolution of emerging viruses that can affect human health.
Article Synopsis
- Researchers isolated a coronavirus called BANAL-20-236 (B236) from Malayan horseshoe bats and found it lacks a key site in its spike protein that is present in SARS-CoV-2.
- * They compared B236's characteristics using human-derived cells and hamster infection experiments, discovering it's less pathogenic and grows slower in respiratory cells compared to SARS-CoV-2, but grows better in intestinal cells.
- * The study suggests that SC2r-CoVs like B236 may primarily replicate in the intestines rather than the respiratory system, supporting prior findings about its behavior in other models.
Vulnerability to APOBEC3G linked to the pathogenicity of deltaretroviruses.
Proc Natl Acad Sci U S A
March 2024
Article Synopsis
- Human retroviruses like HIV and HTLV-1 originate from simian viruses and can lead to serious diseases in humans, despite being less harmful to their natural hosts.
- Research revealed that the human protein APOBEC3G (A3G) causes G-to-A mutations primarily in HTLV-1, while HTLV-2 and STLV-1 have mechanisms to resist these mutations.
- The study found that the antisense proteins from these retroviruses interact differently with A3G, with HTLV-1 exploiting A3G to promote cell growth in a way tied to cancer development, while HTLV-2 and STLV-1 do not have this effect.
Article Synopsis
- The emergence of a new Variant of Interest, XBB.1.5, is linked to mutations from the pre-existing variant XBB.1, specifically an S486P spike mutation and a nonsense mutation in ORF8.
- Phylogenetic analysis indicates that XBB.1.5 maintains similar immune escape abilities compared to XBB.1, and structural studies reveal that the spike proteins of both variants are largely similar.
- Research involving hamsters shows that the ORF8 nonsense mutation in XBB.1.5 reduces MHC suppression and results in lower virulence in this variant compared to XBB.1.
Article Synopsis
- In late 2023, the SARS-CoV-2 BA.2.86 variant emerged alongside the dominant XBB descendants like EG.5.1, distinguishing itself with over 30 mutations in its spike protein.
- Modeling showed BA.2.86 has a higher reproduction number compared to EG.5.1, suggesting it spreads more easily.
- Despite its increased spread, BA.2.86 demonstrated lower pathogenicity and replication capacity in hamsters, indicating it may be less severe, while remaining sensitive to four existing antiviral treatments.
Article Synopsis
- Most research on SARS-CoV-2 variants has concentrated on mutations in spike proteins that influence how the virus infects and spreads.
- This study highlights that there are also significant mutations outside of the spike protein that can affect the virus's behavior.
- Specifically, the study found that certain mutations in the Omicron BA.2 variant, including one in the spike protein and another further down the gene, play crucial roles in defining its characteristics.
Purpose: Previous reports on the outcome of conservative treatment for dropped head syndrome (DHS) are scarce. The purpose of this study was to elucidate the efficacy of conservative treatment for DHS and to identify possible predictive factors relating to the outcome.
Methods: Among 76 DHS patients, conservative treatment (2-3 months collar application, active neck range of motion exercise, and occasional prescription of analgesics) succeeded in 17 patients (22.
Article Synopsis
- - HIV-1 faces resistance from innate antiviral mechanisms in CD4 T lymphocytes and macrophages, particularly from the APOBEC3 (A3) family of proteins, which restrict viral replication.
- - The virus's virion infectivity factor (Vif) helps it overcome this resistance by degrading A3 proteins, and while it also targets other proteins, its main role appears to focus on A3 proteins.
- - Experiments using CRISPR to disrupt specific genes in THP-1 cells show that removing A3 proteins completely restores the infectivity of Vif-deficient HIV-1, highlighting that A3 proteins are the primary target for Vif's function in viral production.
Article Synopsis
- In late 2022, the SARS-CoV-2 Omicron subvariant XBB emerged from the recombination of two existing BA.2 lineages, BJ.1 and BM.1.1.1, during the summer of 2022.
- XBB.1 shows strong resistance to vaccines designed for BA.2/5 and has increased fusogenicity, meaning it can fuse with human cells more efficiently due to changes in its spike protein.
- Research indicates that while XBB.1 is pathogenic, its disease-causing potential in male hamsters is similar to or lower than that of the BA.2.75 variant, marking a notable adaptation in virus evolution through recombination.
Article Synopsis
- In late 2022, several Omicron subvariants emerged globally, characterized by specific amino acid changes in their spike proteins, indicating convergent evolution.
- The study highlights a problematic lineage, BQ.1.1, which shows higher viral fitness due to five critical amino acid substitutions and better evasion of immune responses compared to the BA.5 subvariant.
- In tests on hamsters, BQ.1.1 demonstrated lower pathogenicity than BA.5, revealing insights into the evolutionary patterns of Omicron subvariants up to 2022.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivation of pH-dependent graphene oxide (GO) nanosheets is presented. The observed virus inactivation using an authentic virus (Delta variant) and different GO dispersions at pH 3, 7, and 11 suggests that the higher pH of the GO dispersion yields a better performance compared to that of GO at neutral or lower pH. The current findings can be ascribed to the pH-driven functional group change and the overall charge of GO, favorable for the attachment between GO nanosheets and virus particles.
View Article and Find Full Text PDFUnlabelled: HIV-1 must overcome multiple innate antiviral mechanisms to replicate in CD4 T lymphocytes and macrophages. Previous studies have demonstrated that the APOBEC3 (A3) family of proteins (at least A3D, A3F, A3G, and stable A3H haplotypes) contribute to HIV-1 restriction in CD4 T lymphocytes. Virus-encoded virion infectivity factor (Vif) counteracts this antiviral activity by degrading A3 enzymes allowing HIV-1 replication in infected cells.
View Article and Find Full Text PDFPurpose: The pathology of dropped head syndrome (DHS) is diverse, and reports of surgery for DHS are scarce. We aimed to describe surgery for DHS and to investigate the surgical outcomes thereof.
Methods: We enrolled 40 consecutive patients (six males and 34 females; average age at surgery, 72.
Usefulness of K-line in predicting prognosis of laminoplasty for cervical spondylotic myelopathy.
BMC Musculoskelet Disord
February 2023
Background: K-line is widely recognized as a useful index for evaluating cervical alignment and the size of the cervical ossification at the posterior longitudinal ligament (OPLL). The purpose of this study was to investigate whether the K-line could be a useful clinical tool for predicting the prognosis of laminoplasty (LP) for cervical spondylotic myelopathy (CSM).
Methods: Adult CSM patients scheduled for cervical LP were recruited for this study.
Recent studies have revealed the unique virological characteristics of Omicron, particularly those of its spike protein, such as less cleavage efficacy in cells, reduced ACE2 binding affinity, and poor fusogenicity. However, it remains unclear which mutation(s) determine these three virological characteristics of Omicron spike. Here, we show that these characteristics of the Omicron spike protein are determined by its receptor-binding domain.
View Article and Find Full Text PDFArticle Synopsis
- - The SARS-CoV-2 spike protein plays a crucial role in allowing the virus to enter target cells by facilitating membrane fusion.
- - A new assay using a dual functional split reporter protein has been developed to quantitatively study the fusion process in living cells, enabling real-time monitoring.
- - This method can be applied to different cell types and may help predict how harmful new variants of the virus could be, with further details available in the referenced studies.
Article Synopsis
- The SARS-CoV-2 Omicron BA.2.75 variant, emerging in May 2022, is a distinct descendant of BA.2 and shows a greater reproductive number than the dominant BA.5 variant.
- BA.2.75 demonstrates different responses to vaccines and antibodies, retaining antiviral drug effectiveness but showing variable antibody sensitivity due to unique genetic changes.
- This variant has enhanced ability to bind to human receptors, increased growth efficiency in lung cells, and heightened pathogenicity in hamsters, indicating a potentially greater risk to global health compared to BA.5.
Article Synopsis
- The emergence of various subvariants of the SARS-CoV-2 Omicron BA.2, such as BA.2.9.1, BA.2.11, BA.2.12.1, BA.4, and BA.5, shows that they have higher effective reproduction numbers compared to the original BA.2 strain.
- Neutralization experiments indicate that immunity from previous BA.1/2 infections is less effective against the newer BA.4/5 subvariants, which also replicate more efficiently and exhibit greater cell fusion than BA.2.
- Research using hamsters and structural analysis of the BA.4/5 spike protein suggests that these subvariants are more pathogenic and pose a greater risk to global health