Publications by authors named "Ohtaki M"

Radiobiological studies are ongoing to understand the consequences of internal exposure to neutron-activated radioactive microparticles, which were sprayed over experimental rats and mice. Special attention in these experiments is given to internal irradiation with radioactive microparticles with short-lived neutron-activated radionuclides 31Si (T1/2 = 2.62 h) and 56Mn (T1/2 = 2.

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Background: Disparities in public assistance or the urbanization level of a residential region can affect cancer treatment outcomes. This study aimed to investigate whether these factors affect the overall survival (OS) of patients with epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC) using Tokushukai REAL World Data.

Methods: We analyzed the clinical data of consecutive patients with NSCLC receiving EGFR-tyrosine kinase inhibitors between April 2010 and March 2020 at 46 Tokushukai Medical Group hospitals in Japan.

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Arachnoid cysts have the potential to rupture, leading to the development of a subdural hygroma following minor trauma. Although surgery may be considered in cases of increased intracranial pressure (ICP) or regional neurological symptoms, the optimal approach remains unclear. We report a case of subdural hygroma due to a ruptured arachnoid cyst (SHrAC) with elevated ICP successfully treated with long-term subdural drainage for over 1 month.

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In addition to blood test data, inflammation-based prognostic markers have been used to predict the prognosis of various types of cancer. However, several of these previous studies may be outdated, as they were conducted prior to the widespread adoption of immune checkpoint inhibitors, leading to limited reports on their efficacy. The present study aimed to assess the accuracy of different inflammation-based prognostic markers in patients with advanced or recurrent gastric cancer undergoing nivolumab monotherapy as salvage-line chemotherapy.

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Neutron-activated 31Si is an almost pure beta emitter and is one of the short-lived radionuclides, including beta-gamma emitter 56Mn, which were created in a form of residual radioactivity in the early period after the atomic bombing of Hiroshima and Nagasaki. The features of the biological effects of internal irradiation by these radionuclides are a subject of scientific discussions and research. The publication presents data on internal radiation doses in experimental Wistar rats that were exposed to sprayed neutron-activated microparticles of 31SiO2.

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Cancer-associated thromboembolism (CAT), including venous thromboembolism (VTE) and arterial thromboembolism (ATE), is a frequent complication of advanced pancreatic cancer. However, reports on its incidence and clinical outcomes, especially on ATE, are limited. The present study aimed to investigate the incidence of CAT and its effects on overall survival in patients with metastatic pancreatic cancer.

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Purpose: This study aimed to examine the prognostic impact of concomitant pH-regulating drug use in patients with epidermal growth factor receptor (EGFR)-mutation-positive non-small-cell lung cancer (NSCLC) receiving EGFR-tyrosine kinase inhibitors (TKIs).

Methods: We conducted a nationwide retrospective cohort study and reviewed clinical data of consecutive patients with NSCLC treated with the first-line EGFR-TKIs in 46 hospitals between April 2010 and March 2020. Cox regression analyses were conducted to examine the differences in overall survival (OS) between patients treated with and without concomitant pH-regulating drugs, including potassium-competitive acid blockers (P-CABs), proton pump inhibitors (PPIs), and H-receptor antagonists (HRAs).

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Inflammation-based prognostic markers based on a combination of blood-based parameters, including the modified Glasgow prognostic score (mGPS), have been associated with clinical outcomes in patients with various types of cancer. The present study aimed to evaluate and compare the accuracy of these previously reported markers in patients with metastatic pancreatic cancer receiving first-line chemotherapy. A total of 846 patients were identified between April 2010 and March 2020 as part of a nationwide real-world study from 46 Tokushukai medical group hospitals in Japan.

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Article Synopsis
  • Nearly 80 years after the A-bomb was dropped, debates continue about the radiation doses received by survivors, particularly the neutron doses which are harder to evaluate accurately.
  • Initial measurements of airborne kerma radiation are reliable, but post-explosion exposure from radioactive particles has been largely overlooked due to uncertainties in their behavior.
  • Research indicates that indoor survivors may have experienced over 30% higher radiation exposure due to a higher production of neutron-induced radioactive particles in enclosed environments near the blast's hypocenter.
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Objective: The introduction of new-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has afforded promising overall survival outcomes in clinical trials for non-small-cell lung cancer. We aim to investigate the current adoption rate of these agents and the real-world impact on overall survival among institutions.

Methods: In a nationwide retrospective cohort study of 46 Tokushukai Medical Group hospitals in Japan, we analyzed clinical data of consecutive patients with non-small-cell lung cancer receiving EGFR-TKIs between April 2010 and March 2020.

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The present study aimed to investigate temporal trends in treatment patterns and prognostic factors for overall survival (OS) among patients with metastatic pancreatic cancer. From the Tokushukai REAl-world Data project, 1,093 patients with metastatic pancreatic cancer treated with gemcitabine, tegafur/gimeracil/oteracil (S-1), gemcitabine plus S-1, gemcitabine plus nab-paclitaxel, or fluorouracil, folic acid, oxaliplatin and irinotecan (FOLFIRINOX) between April 2010 and March 2020 were identified. Stratified/conventional Cox regression analyses were conducted to examine associations between patient- and tumor-related factors, study period, hospital volume, hospital type and first-line chemotherapy regimens.

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Introduction: The aim of this study was to determine the safety and efficacy of intravenous (IV) alteplase at 0.6 mg/kg for patients with acute wake-up or unclear-onset strokes in clinical practice.

Methods: This multicenter observational study enrolled acute ischemic stroke patients with last-known-well time >4.

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Aim: To investigate whether any reduction in all-cause mortality and cardiovascular disease morbidity was found over the decade in type 2 diabetes on real-world practice.

Methods: A prospective observational study was performed by following two independent cohorts recruited in 2004 (n = 3286, Cohort 1) and 2014 (n = 3919, Cohort 2). The primary outcome was a composite of onset of cardiovascular disease and death.

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Cohort studies using large-scale databases have become increasingly important in recent years. The Tokushukai Medical Group is a leading medical group in Japan that includes 71 general hospitals nationwide from Hokkaido to Okinawa, with a total of 18,000 beds, and a unified electronic medical record system. This retrospective cohort study aims to evaluate the real-world outcomes of systemic therapy for Japanese patients with cancer using this merit of scale.

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At the detonation of the atomic bombing in Hiroshima and Nagasaki, a significant amount of radionuclides was produced by the neutron induced activation. The residual radiation from the explosion is crucial to the health risk of the people who entered these cities after the bombing and might have inhaled these radioactive materials. Because 56Mn is one of the major radionuclides produced in soil and have not been studied until now, we had conducted a series of experiments using rats to investigate the biological impacts of exposure of 56MnO2 particles.

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There are two types of exposure to atomic bomb (A-bomb) radiation: exposure to initial radiation released at the time of the detonation of the bomb, and exposure to residual radiation, which remains afterwards. Health hazards caused by exposure from residual radiation have not yet been clarified. The purpose of our study was to reveal the relationships between mortality risk from solid cancer and residual radiation based on data from the early entrants to Hiroshima.

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Article Synopsis
  • Manganese-56 was a significant neutron-activated radionuclide released during the atomic bombings, contributing to radiation exposure in nearby areas.
  • The study focused on the spatial microdistribution of radiation doses in lung tissues exposed to 56Mn, highlighting the potential for elevated irradiation of alveoli and ducts.
  • Using the Monte Carlo simulation, researchers found a significant gradient in the absorbed dose in lung epithelial cells, indicating that low-energy electrons from 56Mn decay preferentially irradiate these cells.
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Aim: This study aimed to assess the potential effect of prior antithrombotic medication for thrombolysis in an unknown onset stroke.

Methods: This was a predefined sub-analysis of the THAWS trial. Stroke patients with a time last known well >4.

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Copper-based sulfides are promising materials for thermoelectric applications, which can convert waste heat into electricity. This study reports the enhanced thermoelectric performance of CuVGeS colusite substitution of antimony (Sb) for germanium (Ge) and introduction of copper (Cu) as an interstitial atom. The crystal structure of the solid solutions and Cu-rich compounds were analyzed by powder X-ray diffraction and scanning transmission electron microscopy.

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The temperature dependence thermal conductivity of the indium-gallium-zinc oxide (IGZO) thin films was investigated with the differential three-omega method for the clear demonstration of nanocrystallinity. The thin films were deposited on an alumina (α-AlO) substrate by direct current (DC) magnetron sputtering at different oxygen partial pressures ([PO] = 0%, 10%, and 65%). Their thermal conductivities at room temperature were measured to be 1.

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Article Synopsis
  • A study aimed to identify stroke patients who could benefit from low-dose thrombolysis by analyzing data from the THAWS trial, which involved patients with unclear onset strokes.
  • Patients were divided based on ischemic core size and assessed after receiving alteplase or standard treatment, with a goal to determine favorable outcomes at 90 days.
  • Results showed similar rates of favorable outcomes and intracranial hemorrhage in both treatment groups, but the alteplase group had better outcomes in specific patient subsets with lower ischemic scores.
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The experiment was performed in support of a Japanese initiative to investigate the biological effects of irradiation from residual neutron-activated radioactivity that resulted from the A-bombing. Radionuclide Mn (T = 2.58 h) is one of the main neutron-activated emitters during the first hours after neutron activation of soil dust particles.

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Investigating initial behavioral changes caused by irradiation of animals might provide important information to aid understanding of early health effects of radiation exposure and clinical features of radiation injury. Although previous studies in rodents suggested that radiation exposure leads to reduced activity, detailed properties of the effects were unrevealed due to a lack of proper statistical analysis, which is needed to better elucidate details of changes in locomotor activity. Ten-week-old male Wistar rats were subjected to single point external whole-body irradiation with Co gamma rays at 0, 2.

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Background: Various techniques are applied in laparoscopic surgery for the treatment of urachal remnants, which are less invasive and associated with lower morbidity. We herein report a case series in which we treated urachal remnants and medial umbilical ligaments using a laparoscopic approach.

Case Presentation: From 2015 to 2019, seven patients (male, n = 5; female, n = 2) with a urachal remnant were treated by laparoscopic surgery in our institute.

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Background and Purpose- We assessed whether lower-dose alteplase at 0.6 mg/kg is efficacious and safe for acute fluid-attenuated inversion recovery-negative stroke with unknown time of onset. Methods- This was an investigator-initiated, multicenter, randomized, open-label, blinded-end point trial.

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