Munechika Misumi - Academia.edu (original) (raw)

Papers by Munechika Misumi

European Journal of Epidemiology

Past reports indicated that total-body irradiation at low to moderate doses could be responsible ... more Past reports indicated that total-body irradiation at low to moderate doses could be responsible for cardiovascular disease risks, but the mechanism remains unclear. The purpose of this study was to investigate the association between radiation exposure and atherosclerosis, an underlying pathology of cardiovascular diseases, in the Japanese atomic bomb survivors. We performed a cross-sectional study measuring 14 clinical-physiological atherosclerosis indicators during clinical exams from 2010 to 2014 in 3274 participants of the Adult Health Study cohort. Multivariable analyses were performed by using a structural equation model with latent factors representing underlying atherosclerotic pathologies: (1) arterial stiffness, (2) calcification, and (3) plaque as measured with indicators chosen a priori on the basis of clinical-physiological knowledge. Radiation was linearly associated with calcification (standardized coefficient per Gy 0.15, 95 % confidence interval: CI [0.070, 0.23]) ...

Radiation and Environmental Biophysics, 2022

A previous study of peripheral blood lymphocyte translocations around age 40 among atomic-bomb su... more A previous study of peripheral blood lymphocyte translocations around age 40 among atomic-bomb survivors exposed in utero revealed no overall association with radiation dose—despite a clear association between translocations and dose among their mothers—but the data suggested an increase at doses below 100 mGy with a definite peak. That analysis of the in utero-exposed survivors did not adjust for their subsequent smoking behavior, an established cause of chromosomal aberrations, or their subsequent exposures to medical irradiation, a potential mediator. In addition, atomic-bomb survivor radiation dose estimates have subsequently been updated and refined. We therefore re-estimated the dose response using the latest DS02R1 dose estimates and adjusting for smoking as well as for city and proximal–distal location at the time of exposure to the atomic bomb. Sex of the survivor, mother’s age around the time of conception, and approximate trimester of gestation at the time of exposure wer...

Radiation Research, 2022

High-dose radiation in childhood such as is used in radiation therapy causes cognitive decline, b... more High-dose radiation in childhood such as is used in radiation therapy causes cognitive decline, but there is insufficient research on the cognitive effects of low- to medium-dose radiation. We aimed to reveal the association between atomic bomb radiation exposure in childhood and late-life neurocognitive function. In 2011 and 2013, we mailed the Neurocognitive Questionnaire (NCQ) to subjects who were 12 years old or younger at the time of the atomic bombing. We converted the four NCQ subscales (metacognition, emotional regulation, motivation/organization, and processing speed) to T scores and defined the highest 10% of the controls (exposure dose < 5 mGy) as impaired. We used a generalized linear mixed model to evaluate the effect of radiation exposure on T scores and percentage impaired. We enrolled 859 participants. At the time of the bombing, the mean (SD) age was 6.7 (3.8) years for the control (N = 390) and 6.1 (3.8) years for the exposed (N = 469). At the time of replying t...

Radiation Research, 2020

Dosimetric measurement error is known to potentially bias the magnitude of the dose response, and... more Dosimetric measurement error is known to potentially bias the magnitude of the dose response, and can also affect the shape of dose response. In this report, generalized relative and absolute rate models are fitted to the latest Japanese atomic bomb survivor solid cancer, leukemia and circulatory disease mortality data (followed from 1950 through 2003), with the latest (DS02R1) dosimetry, using Bayesian techniques to adjust for errors in dose estimates and assessing other model uncertainties. Linear-quadratic models are fitted and used to assess lifetime mortality risks for contemporary UK, USA, French, Russian, Japanese and Chinese populations. For a test dose of 0.1 Gy absorbed dose weighted by neutron relative biological effectiveness, solid cancer, leukemia and circulatory disease mortality risks for a UK population using a generalized linearquadratic relative rate model were estimated to be 3.88% Gy −1 [95% Bayesian credible interval (BCI): 1.17, 6.97], 0.35% Gy −1 (95% BCI: −0.03, 0.78) and 2.24% Gy −1 (95% BCI: −0.17, 13.76), respectively. Using a generalized absolute rate linear-quadratic model at 0.1 Gy, the lifetime risks for these three end points were estimated to be 3.56% Gy −1 (95% BCI: 0.54, 6.78), 0.41% Gy −1 (95% BCI: 0.01, 0.86) and 1.56% Gy −1 (95% BCI: −1.10, 7.21), respectively. There was substantial evidence of curvature for solid cancer (in particular, the group of solid cancers excluding lung, breast and stomach cancers) and leukemia, so that for solid cancer and leukemia, estimates of excess risk per unit dose were nearly doubled by increasing the dose from 0.01 to 1.0

Proceedings of the World …, 2010

AbstractThis study deals with the combined effects of misclassifications incidental to diagnosti... more AbstractThis study deals with the combined effects of misclassifications incidental to diagnostics, or a binary response, and genotyping, or a discrete covariate, on the statistical power of a logistic model testing for a treatment effect. The loss of power due to differential ...

Introduction 1,5-Anhydroglucitol (1,5-AG) is a biomarker of glucose spikes. To evaluate the effec... more Introduction 1,5-Anhydroglucitol (1,5-AG) is a biomarker of glucose spikes. To evaluate the effect of acute glucose excursions on cancer death, we clarified the association between 1,5-AG and cancer mortality among Japanese individuals with normal glucose tolerance. Research design and methods We measured 1,5-AG in 6783 (2842 men, 3941 women) individuals with normal fasting and 2-hour plasma glucose who received a 75 g oral glucose tolerance test between 1994 and 2012. They were followed for mortality until August 2013. A systematic review of death certificates was used to confirm the cause of death. We divided the participants into four groups according to the quartile of 1,5-AG level at registration. We used Cox regression to clarify the association between 1,5-AG levels and cancer mortality with multivariate adjustment for possible confounders. Results During the follow-up period (median, 10.0 years), 140 men and 109 women died of cancer. The HR for cancer mortality of the lowest...

Journal of Diabetes Investigation, 2019

Aims/Introduction: We performed a retrospective, longitudinal analysis of β-cell function between... more Aims/Introduction: We performed a retrospective, longitudinal analysis of β-cell function between a diabetes mellitus (DM) group including those that progressed to DM during the follow-up period and a diabetic type with HbA1c<6.5 group including those that progressed to Accepted Article This article is protected by copyright. All rights reserved. a diabetic type during the follow-up period. β-cell function was assessed using HOMA-β. Materials and Methods: The relationship between the duration of DM or the diabetic type and pancreatic β-cell function was compared between the DM group (1,817) and diabetic type with HbA1c<6.5 group (1,843) using results from an oral glucose tolerance test (OGTT). Linear mixed effects models were used to analyze repeated measurements of OGTT. Results: The slope of the regression line of β-cell function for the duration of the DM group was-2.2%/year before the diagnosis. The slope differed after the diagnosis, and the difference was 1.3. The slope of the diabetic type group was-1.2%/year, and no significant difference was observed in the slope before and after the diagnosis. β-cell function at the onset was 54.3% in the diabetic type group and 40.6% in the DM group, and the slope of the regression line was significantly larger in the DM group. We divided the DM and diabetic type with HbA1c<6.5 groups into obese and non-obese subjects. β-cell function declined more with obesity. Conclusions: Subsequent declines in β-cell function were faster in the DM group than that in the diabetic type with HbA1c<6.5 group, and increased with obesity.

Software Quality Journal, 2008

Quantitative process management (QPM) and causal analysis and resolution (CAR) are requirements o... more Quantitative process management (QPM) and causal analysis and resolution (CAR) are requirements of capability maturity model (CMM) levels 4 and 5, respectively. They indicate the necessity of process improvement based on objective evidence obtained from statistical analysis of metrics. However, it is difficult to achieve these requirements in practice, and only a few companies have done so successfully. Evidence-based 2 risk-management methods have been proposed for the control of software processes, but are not fully appreciated, compared to clinical practice in medicine. Furthermore, there is no convincing answer as to why these methods are difficult to incorporate in software processes, despite the fact that they are well established in some business enterprises and industries. In this paper, we challenge this issue, point out a problem peculiar to software processes, and develop a generally applicable method for identifying the risk of failure for a project in its early stages. The proposed method is based on statistical analyses of process measurements collected continuously throughout a project by a risk assessment and tracking system (RATS). Although this method may be directly applicable to only a limited number of process types, the fundamental idea might be useful for a broader range of applications.

Journal of Radiation Research

Exposure to high-doses of ionizing radiation has been reported to be associated with the risk of ... more Exposure to high-doses of ionizing radiation has been reported to be associated with the risk of stroke. However, risks associated with lower dose exposures remain unclear, and there is little information available for the risk modification according to the dose-rate. There are few studies using animal models which might be able to provide complementary information on this association. In this study, the male stroke-prone spontaneously hypertensive rat (SHRSP) was used as a model animal. The rats were acutely irradiated with doses between 0 and 1.0 Gy or chronically irradiated with a cumulative dose of 0.5 or 1.0 Gy (at a dose rate of 0.05 or 0.1 Gy/day, respectively). The onset time of stroke related symptoms in SHRSP was used as an endpoint for evaluating the effects of low dose and the low dose-rate gamma-ray exposures. With respect to acute exposure, the time to the onset of stroke in the irradiated rats suggested the presence of a threshold around 0.1 Gy. For the low dose-rate ...

International Journal of Radiation Biology

British Journal of Haematology

Radiation Research

In this work, we utilized spontaneously hypertensive rats (SHR) and Wister Kyoto rats (WKY), from... more In this work, we utilized spontaneously hypertensive rats (SHR) and Wister Kyoto rats (WKY), from which the SHR was established, to evaluate the effects of whole-body acute radiation on the cardiovascular system at doses from 0 to 4 Gy. In the irradiated SHR, the systolic blood pressure (SBP) increased with increasing dose, while body weight gain decreased with increasing radiation dose. Furthermore, pathological observations of SHR demonstrated that the number of rats with cystic degeneration in the liver increased with increasing dose. The effects observed among SHR, such as increased SBP and retardation of body weight gain, appear very similar to those observed in Japanese atomic bomb survivors. In contrast, the SBP among WKY did not change relative to dose; the body weight, however, did change, as in the SHR. Therefore, the association between radiation exposure and SBP, but not between radiation exposure and retardation of body weight gain, may be affected by genetic background...

BMC Genomics

Background: Common variants have explained less than the amount of heritability expected for comp... more Background: Common variants have explained less than the amount of heritability expected for complex diseases, which has led to interest in less-common variants and more powerful approaches to the analysis of whole-genome scans. Because of low frequency (low statistical power), less-common variants are best analyzed using SNP-set methods such as gene-set or pathway-based analyses. However, there is as yet no clear consensus regarding how to focus in on potential risk variants following set-based analyses. We used a stepwise, telescoping approach to analyze commonand rare-variant data from the Illumina Metabochip array to assess genomic association with colorectal cancer (CRC) in the Japanese sub-population of the Multiethnic Cohort (676 cases, 7180 controls). We started with pathway analysis of SNPs that are in genes and pathways having known mechanistic roles in colorectal cancer, then focused on genes within the pathways that evidenced association with CRC, and finally assessed individual SNPs within the genes that evidenced association. Pathway SNPs downloaded from the dbSNP database were cross-matched with Metabochip SNPs and analyzed using the logistic kernel machine regression approach (logistic SNP-set kernel-machine association test, or sequence kernel association test; SKAT) and related methods. Results: The TGF-β and WNT pathways were associated with all CRC, and the WNT pathway was associated with colon cancer. Individual genes demonstrating the strongest associations were TGFBR2 in the TGF-β pathway and SMAD7 (which is involved in both the TGF-β and WNT pathways). As partial validation of our approach, a known CRC risk variant in SMAD7 (in both the TGF-β and WNT pathways: rs11874392) was associated with CRC risk in our data. We also detected two novel candidate CRC risk variants (rs13075948 and rs17025857) in TGFBR2, a gene known to be associated with CRC risk. Conclusions: A stepwise, telescoping approach identified some potentially novel risk variants associated with colorectal cancer, so it may be a useful method for following up on results of set-based SNP analyses. Further work is required to assess the statistical characteristics of the approach, and additional applications should aid in better clarifying its utility.

JAMA Network Open

IMPORTANCE Weight cycling is associated with the risk of mortality from heart disease, but many s... more IMPORTANCE Weight cycling is associated with the risk of mortality from heart disease, but many studies have not distinguished between simple nonlinear (monotone) weight changes and more complex changes that reflect fluctuations. OBJECTIVE To assess whether extreme body weight variation is associated with mortality after controlling for nonlinear weight changes. DESIGN, SETTING, AND PARTICIPANTS In this prospective clinical cohort study, 4796 Japanese atomic bomb survivors were examined in the clinic as part of a biennial health examination and research program. The study consisted of a 20-year longitudinal baseline period (

International Journal of Cancer

Journal of the American Heart Association

Background-Past reports suggested that total-body irradiation at 0.5 to 1.0 Gy could be responsib... more Background-Past reports suggested that total-body irradiation at 0.5 to 1.0 Gy could be responsible for atherosclerosis. Peripheral artery disease (PAD) is a manifestation of systematic atherosclerosis. Whether the consequences of a low-to-moderate dose of radiation include increased risk of PAD remains to be determined. The purpose of this study was to examine the association between radiation exposure and prevalence of PAD among Japanese atomic bomb survivors. Methods and Results-Radiation exposure from the atomic bombing was assessed in 3476 participants (41.1% men, mean age 74.8 years with SD 6.4 years) with a cross-sectional survey in 2010 to 2014. Left-and right-side ankle-brachial indexes and upstroke time (UT) were obtained using oscillometric VP-2000. PAD was defined as an ankle-brachial index of 1.0 or less or a prior history related to revascularization. UT was considered a sensitive marker of early-stage PAD. Association between radiation exposure and PAD or UT was assessed using multivariable regression analyses with adjustment for potential confounding factors. Of 3476 participants, 79 (2.3%) were identified as having prevalent PAD. Multivariate logistic regression analysis indicated that radiation dose was unrelated to PAD prevalence (odds ratio, 0.83; 95% confidence interval [0.57-1.21]). UT appeared to increase with radiation dose, but the increase was not statistically significant (1.09 ms/Gy; 95% confidence interval [À0.17 to 2.36]). Conclusions-We found no clear association of radiation dose with PAD, but it remains to be determined whether UT is associated with radiation dose.