Publications by authors named "Iwatsubo T"

Decades of research have provided evidence that Alzheimer's disease (AD) is caused in part by cerebral accumulation of amyloid beta-protein (Aβ). In 2023, the US Food and Drug Administration gave full regulatory approval to a disease-modifying Aβ antibody for early AD. Secondary prevention trials with Aβ antibodies are underway.

View Article and Find Full Text PDF

Background And Aim: Gel immersion (GI) endoscopy provides a good visual field in endoscopic submucosal dissection (ESD); however, its clinical outcomes are poorly understood. This study aimed to compare the treatment outcomes between esophageal gel immersion endoscopic submucosal dissection (GI-ESD) and conventional ESD (C-ESD) to determine the safety and efficacy of GI-ESD.

Methods: The data of 71 consecutive patients who underwent esophageal ESD between April 2021 and March 2023 at a Japanese tertiary center were retrospectively reviewed.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates public and clinical specialists' perceptions regarding preparedness for administering disease-modifying treatments (DMT) for Alzheimer’s disease, focusing on the newly approved drug lecanemab.
  • Conducted through online and mail surveys, it gathered responses from over 2,000 participants, highlighting significant differences in views about treatment eligibility and efficacy between general public respondents and clinical specialists.
  • While both groups were generally supportive of prioritizing patients for treatment, the public expressed more restrictive views on who qualifies for DMT and appeared more optimistic about its effectiveness compared to specialists.
View Article and Find Full Text PDF
Article Synopsis
  • The global incidence of dementia, particularly Alzheimer's disease (AD), is increasing, prompting the need for effective treatments like aducanumab, which targets amyloid beta involved in AD.
  • Aducanumab was approved by the FDA in June 2021 for treating early AD through an accelerated approval process, supported by data from two global phase 3 studies, EMERGE and ENGAGE.
  • In these studies, Japanese participants with a confirmed diagnosis of mild cognitive impairment or mild AD dementia were evaluated for the drug's efficacy, safety, and pharmacokinetics, with results aligning closely with the overall findings.
View Article and Find Full Text PDF

A 55-year-old man with a history of distal gastrectomy was admitted to our hospital due to gastrointestinal bleeding from an anastomotic ulcer. After endoscopic hemostasis, his oral intake resumed after 1 day of fasting; however, he could not ingest food because of early satiety and nausea on the fifth day of oral intake resumption. Esophagogastroduodenoscopy was performed again to investigate the cause of anorexia and revealed a massive gastrolithiasis that was not observed in the previous esophagogastroduodenoscopy, which was diagnosed as the cause of his anorexia.

View Article and Find Full Text PDF
Article Synopsis
  • Anti-amyloid drugs like lecanemab used for early Alzheimer's disease can cause adverse events (AEs), including specific brain imaging abnormalities and infusion reactions.
  • A meta-analysis was conducted to assess the predictive value of these adverse events, revealing that ARIA-E has a high positive predictive value (PPV) of 0.915, while ARIA hemorrhage has a low PPV of 0.630.
  • The findings indicate that the impact of AEs, especially ARIA-E, can influence the results of clinical trials and emphasize the need to reduce potential biases stemming from these events.
View Article and Find Full Text PDF
Article Synopsis
  • Alzheimer's disease is a prevalent form of dementia in older adults, making up 60-70% of dementia cases, and recent advancements have focused on anti-amyloid antibody drugs to slow its progression.
  • Key drugs like aducanumab and lecanemab have been approved, while donanemab is anticipated to receive approval soon; additional drugs are in development.
  • Despite these advancements, challenges like potential side effects (e.g., ARIA) and the need for better healthcare support systems remain critical for the successful use of these therapies.
View Article and Find Full Text PDF

The intracerebral spread of tau is a critical mechanism associated with functional decline in Alzheimer's disease (AD) and other tauopathies. Recently, a hypothesis has emerged suggesting that tau propagation is linked to functional neuronal connections, specifically driven by neuronal hyperactivity. However, experimental validation of this hypothesis remains limited.

View Article and Find Full Text PDF
Article Synopsis
  • - The approval of lecanemab for early Alzheimer's treatment in 2023 revealed regional differences in the availability and frequency of MRI scans needed to monitor side effects of the therapy, potentially impacting consistent care nationwide.
  • - The study analyzed MRI scan data across Japan from 2015 to 2021, using a model to assess variations in MRI usage and categorizing regions based on frequency and types of MRI scanners.
  • - Findings indicated that 1.5T MRIs were the most common, with a slight increase in 3.0T MRI usage, particularly in western Japan, and emphasized the need for better regional healthcare readiness for managing Alzheimer's treatments.
View Article and Find Full Text PDF

-ε4 allele[s] is a risk factor for Alzheimer's disease (AD) and Amyloid-Related Imaging Abnormalities (ARIA) in anti-amyloid beta therapy, and is also associated with cerebrovascular risk factors such as hyperlipidemia or atherosclerosis. During AD clinical trials, -ε4 carriers may experience neuropsychiatric adverse events (AEs) related to these risks, complicating the differentiation of ARIA from cerebrovascular events based on symptoms. This study aimed to examine the hypothetical impact of considering the -ε4 allele's risk for non-ARIA AEs during AD clinical trials.

View Article and Find Full Text PDF

Background: Sarcopenia has been reported to be associated with short-term outcomes after gastric endoscopic submucosal dissection (ESD). The "strength, assistance with walking, rising from a chair, climbing stairs, and falls" (SARC-F) questionnaire has been widely used as a screening tool for sarcopenia; however, SARC-F combined with body mass index and age (SARC-F+EBM) has recently been reported to be more useful than SARC-F alone. This study aimed to investigate the association between sarcopenia, measured using SARC-F+EBM, and short-term outcomes after gastric ESD.

View Article and Find Full Text PDF
Article Synopsis
  • Developing therapies for Alzheimer's disease (AD) is most effective when targeting its early stages, such as mild cognitive impairment (MCI), before severe symptoms occur.* -
  • The AD Neuroimaging Initiative (ADNI) in the U.S. and the similar J-ADNI study in Japan are focusing on early detection through imaging and biomarkers, demonstrating similar progression patterns in patients.* -
  • Recent clinical successes, like the approval of lecanemab and the completion of trials for donanemab, alongside new initiatives like the J-TRC study, are paving the way for faster development of disease-modifying therapies for AD.*
View Article and Find Full Text PDF

Background: Maximizing the efficiency to screen amyloid-positive individuals in asymptomatic and non-demented aged population using blood-based biomarkers is essential for future success of clinical trials in the early stage of Alzheimer's disease (AD). In this study, we elucidate the utility of combination of plasma amyloid-β (Aβ)-related biomarkers and tau phosphorylated at threonine 217 (p-tau217) to predict abnormal Aβ-positron emission tomography (PET) in the preclinical and prodromal AD.

Methods: We designed the cross-sectional study including two ethnically distinct cohorts, the Japanese trial-ready cohort for preclinica and prodromal AD (J-TRC) and the Swedish BioFINDER study.

View Article and Find Full Text PDF

Background: Although proton pump inhibitors (PPIs) or potassium-competitive acid blocker (PCAB) are useful in peptic ulcer prevention, their efficacy in preventing other gastrointestinal bleeding remains unclear. This study aimed to identify the status of gastrointestinal bleeding in the modern era when PPIs are widely used.

Methods: This study included patients who underwent percutaneous coronary intervention (PCI) between 2018 and 2019 at two high-volume centers.

View Article and Find Full Text PDF

Background: Primary outcome measure in the clinical trials of disease modifying therapy (DMT) drugs for Alzheimer's disease (AD) has often been evaluated by Clinical Dementia Rating sum of boxes (CDRSB). However, CDR testing requires specialized training and 30-50 minutes to complete, not being suitable for daily clinical practice.

Objective: Herein, we proposed a machine-learning method to estimate CDRSB changes using simpler cognitive/functional batteries (Mini-Mental State Examination [MMSE] and Functional Activities Questionnaire [FAQ]), to replace CDR testing.

View Article and Find Full Text PDF

Background: We have been conducting a Japanese trial-ready cohort web study since 2019 as a web-based online registry to enroll individuals with preclinical Alzheimer's disease to facilitate trials on Alzheimer's disease prevention. The usability of a website might be an important factor in determining user participation and retention.

Objectives: We conducted a user questionnaire survey to analyze the usability of the Japanese trial-ready cohort website and user characteristics for future website improvement.

View Article and Find Full Text PDF

Background:  Alzheimer's disease (AD) is pathologically characterized by the abnormal accumulation of Aβ and tau proteins. There has long been a keen interest among researchers in understanding how Aβ and tau are ultimately cleared in the brain. The discovery of this glymphatic system introduced a novel perspective on protein clearance and it gained recognition as one of the major brain clearance pathways for clearing these pathogenic proteins in AD.

View Article and Find Full Text PDF

Genetic variants in the () gene affect the onset and progression of Alzheimer's disease (AD). The Christchurch ( Ch) variant has been identified as the most prominent candidate for preventing the onset and progression of AD. In this study, we generated isogenic Ch/Ch human-induced pluripotent stem cells (iPSCs) from / healthy control female iPSCs and induced them into astrocytes.

View Article and Find Full Text PDF

Conjugation of ATG8 to single membranes (CASM) at endolysosomal compartments has attracted attention as the non-autophagic function of the Atg8-family protein conjugation system, and the V-ATPase-ATG16L1 axis has emerged as a core mechanism. Our recent research has revealed that this mechanism contributes to the lysosomal recruitment and activation of LRRK2, a Parkinson disease-associated kinase that phosphorylates a subset of RAB GTPases. The activated LRRK2 under CASM-causing lysosomal stress acts to regulate lysosomal morphology and stimulate extracellular secretion of lysosomal contents, thereby promoting the lysosomal stress response.

View Article and Find Full Text PDF

A 70-year-old man who had undergone treatment for gastroesophageal reflux disease (GERD) by a family doctor presented to our hospital with severe heartburn and dysphagia despite taking vonoprazan (20 mg) for 3 months. A diagnosis of vonoprazan-refractory nonerosive reflux disease was made based on esophagogastroduodenoscopy and esophageal function examinations. The patient elected to undergo endoscopic treatment for GERD.

View Article and Find Full Text PDF