Publications by authors named "Terumasa Ikeda"

Improved antiretroviral therapy (ART) has significantly increased the life expectancy of people living with HIV (PLWH). At the same time, other complications like metabolic syndrome (MetS) are coming up as new challenges to handle. This review aims to explore the emerging evidence of gut microbiome and virome alterations in human immunodeficiency virus-1 (HIV-1) infection and associated metabolic disorders, such as type-2 diabetes (T2DM) and cardiovascular disease (CVD), with a focus on their interplay, contribution to immune dysfunction, and potential as therapeutic targets.

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Anterior cervical fusion surgery is widely performed for cervical spine disorders. While generally effective, late complications such as vertebral fractures in fused segments are rare but clinically significant, especially in elderly patients with bone fragility. We report here the case of an 84-year-old woman who developed a flexion deformity fracture at a fused cervical segment more than 20 years after anterior cervical corpectomy and fusion with autologous iliac bone grafting and C4 laminoplasty.

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The global circulation of SARS-CoV-2 in human populations has driven the emergence of Omicron subvariants, which have become highly diversified through recombination. In late 2024, SARS-CoV-2 Omicron XEC variant emerged from the recombination of two JN.1 progeny, KS.

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Retroviruses integrate their genetic material into the host genome, enabling persistent infection. Human T cell leukaemia virus type 1 (HTLV-1) and human immunodeficiency virus type 1 (HIV-1) share similarities in genome structure and target cells, yet their infection dynamics differ drastically. While HIV-1 leads to high viral replication and immune system collapse, HTLV-1 establishes latency, promoting the survival of infected cells and, in some cases, leading to leukaemia.

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Osteopetrosis is a rare group of genetic disorders characterized by excessive bone density due to impaired osteoclast function and can lead to various complications, including fractures and immune dysfunction. We describe the case of a 63-year-old man with osteopetrosis who presented with cervical discomfort and was diagnosed with an anterior arch fracture of the atlas, a rare spontaneous fracture following C1 laminectomy. Initially, no neurological abnormalities were observed, and imaging confirmed the continuity of the transverse ligament.

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The apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3 (APOBEC3/A3) family of cytosine deaminases serves as a key innate immune barrier against invading retroviruses and endogenous retroelements. The A3 family's restriction activity against these parasites primarily arises from their ability to catalyze cytosine-to-uracil conversions, resulting in genome editing and the accumulation of lethal mutations in viral genomes. Additionally, non-editing mechanisms, including deaminase-independent pathways, such as blocking viral reverse transcription, have been proposed as antiviral strategies employed by A3 family proteins.

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Purpose: The pathomechanism of dropped head syndrome (DHS) is unclear. In this study, we aimed to examine the features of the paraspinal cervical muscles in patients with DHS by analyzing the volume of these muscles using magnetic resonance imaging (MRI).

Methods: Thirty-six patients with DHS and 25 patients with cervical spondylotic myelopathy (controls) were enrolled.

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Article Synopsis
  • Poncet disease (PD) is a rare condition linked to acute tuberculosis that impacts joints, specifically noted in a 76-year-old patient with symptoms in the hands and spine.
  • Radiographic imaging identified destructive bone lesions in the trapezium and spine, leading to a biopsy that confirmed TB-related damage.
  • The case emphasizes the need to consider PD in elderly patients showing multiple TB foci, particularly affecting the hands, and the patient was referred to a specialized TB facility for treatment.
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Background: 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.

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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.

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Severe 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.

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  • 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.
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  • 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.
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  • 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.
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  • 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.
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  • 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.
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  • 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.
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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.

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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.
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  • 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.
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  • 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.
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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.

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