再灌流後急性心筋梗塞患者におけるリバースリモデリングと非造影T1低信号梗塞コア

Background: Non-contrast T1 hypointense infarct cores (ICs) within infarcted myocardium detected using cardiac magnetic resonance imaging (CMR) T1 mapping may help assess the severity of left ventricular (LV) injury. However, because the relationship of ICs with chronic LV reverse remodeling (LVRR) is unknown, this study aimed to clarify it. Methods and Results: We enrolled patients with reperfused AMI who underwent baseline CMR on day-7 post-primary percutaneous coronary intervention (n=109) and 12-month follow-up CMR (n=94). Correlations between ICs and chronic LVRR (end-systolic volume decrease ≥15% at 12-month follow-up from baseline CMR) were investigated. We detected 52 (47.7%) ICs on baseline CMR by non-contrast-T1 mapping. LVRR was found in 52.1% of patients with reperfused AMI at 12-month follow-up. Patients with ICs demonstrated higher peak creatine kinase levels, higher B-type natriuretic peptide levels at discharge, lower LV ejection fraction at discharge, and lower incidence of LVRR than those without ICs (26.5% vs. 73.3%, P<0.001) at follow-up. Multivariate logistic regression analysis showed that the presence of ICs was an independent and the strongest negative predictor for LVRR at 12-month followup (hazard ratio: 0.087, 95% confidence interval: 0.017–0.459, P=0.004). Peak creatine kinase levels, native T1 values at myocardial edema, and myocardial salvaged indices also correlated with ICs. Conclusions: ICs detected by non-contrast-T1 mapping with 3.0-T CMR were an independent negative predictor of LVRR in patients with reperfused AMI.博士（医学）・乙第1529号・令和5年3月15

Novel adsorptive type apheresis device Immunopure for ulcerative colitis from clinical perspectives based on clinical trials : Japan and Europe.

Several adsorptive type devices for ulcerative colitis are used for the induction of remission in patients with active severe disease worldwide. In 2020, the novel apheresis device Immunopure for ulcerative colitis was launched in Japan. Immunopure, like the polyethylene terephthalate column, uses polyarylate, a type of polyester resin, as the adsorbent. Similar to the cellulose acetate column, Immunopure is filled with adsorbent beads and expected to provide ease of use, with minimal risk of column clogging. Immunopure adsorbs leukocytes and platelets, especially activated platelets and platelet-leukocyte aggregates. In this article, the capability of Immunopure is evaluated from clinical perspective based on a clinical trial in Japan/Europe. As a result, Immunopure is comparable to other products in clinical effectiveness and indicated for the treatment of patients with refractory moderate ulcerative colitis, making it highly useful in clinical practice

The CUtil package which enables GPU computation in R

There are some R packages which uses GPU for computation, and the better performance is provided by GPU-equipped computers. However, the current number of implemented functions in their packages is limited because special procedures are required for utilization of GPU, such as memory allocation in video memory, and data transfer between main memory and video memory. Furthermore, these packages are not easy to use for Windows users because binary packages are not provided, and it is not easy for Windows users to build a developing environment. Since there seems to be a large number of potential Windows users, it is beneficial to develop a package which enables GPU computing easily on Windows. Therefore, we began to develop a new package which utilize GPU in computation with minimum modification of R source code, and also can be used easily for Windows users. The package development is ongoing, and the detail specifications are not fixed, except that the package is developed with NVIDIA\u27s CUDA toolkit. Our package CUtil (CUDA Utility package) will be equipped with the following features.As described above, the first feature is that Windows users will be able to use this package easily. This package will be available from CRAN, and we will also try to make Windows binary packages available. The second feature is that after loading the package, the frequently used operators and functions can be overridden. With this overriding, we can enjoy GPU computation performance with minimum modification of R source code. The third feature is that the package minimize the data transfer cost between main memory and video memory. The data on video memory is treated as external pointer in R objects, and once the R object on main memory is transferred to video memory for GPU computation, the data is kept on video memory as R objects. The next time of the GPU computation, the data can be used directly by GPU without the data transfer. Because it is known that the proportion of time needed for the data transfer is relatively high, this advantage will be beneficial especially for a long series of computations, such as Markov chain Monte Carlo methods in Bayesian statistics. Other than these features, we are going to implement double precision floating-point and complex number computation in addition to single floating-point, and garbage-collection, which enables us to use a small amount of video memory effectively. This package will require computers with NVIDIA\u27s GPU (compute capability is equal to or greater than 2.0).The R User Conference 201

Joint effect of occupational ionizing radiation and cigarette smoking on lung cancer mortality in the US radiologic technologists

Lung cancer has been associated with high doses of radiation. Studies of populations with low, protracted exposures have provided little or inconsistent evidence of a dose-response, possibly due to difficulty in taking into account the effect of cigarette smoking, which may confound or interact with radiation exposure. While the joint effect of radiation and smoking has been well investigated in several studies, there is limited information about the joint effect of chronic low LET radiation exposure and smoking. We examined lung cancer mortality risk among 106,029 US radiologic technologists who were cancer-free at a baseline questionnaire with follow-up from the baseline questionnaire until the end of 2007. The average follow-up was 20.7 years and there were 843 lung cancer deaths. Cumulative lung doses (mean 0.017, range 0-0.81Gy) were estimated using a Monte Carlo dosimetry system. Poisson regression models for excess relative risk (ERR) were employed to examine the joint effect of radiation and smoking, adjusted for age, sex, birth year and race. Multiplicative and additive interaction forms were compared using the AIC. An ERR model with additive interaction fit best. The ERR per Gy for lung cancer mortality was estimated to be 10.94 (-2.57, 24.46) and the ERR per 20 pack-years of cigarettes smoked, 1.10 (0.41, 1.79).日本放射線影響学会第56会大

Parametric weighting approach for effect modification by age at exposure in cumulative covariates

Since the Fukushima nuclear power plant accident, there is an increasing interest in low-dose, long-term radiation exposure in the field of radiation effect research, and epidemiological data using cumulative radiation dose is being analyzed. Cumulative exposure covariates included in statistical models are dependent on the strong and implicit assumption that risks from exposure in the different periods are equal throughout study span.A new approach of weighted cumulative exposure for effect modification was proposed. In this proposed approach, cumulative exposure is considered as a combination of single exposure components in different time periods, and weighted cumulative exposure is calculated as the weighted summation of single doses. Exponential functions were assumed for the weight function and parameters included in the weight function were also estimated with the other parameters in the parameter optimization procedure. The performance of the proposed approach was evaluated through simulation studies and applied to a long-term cohort study of cancer mortality among female nuclear weapons workers.Based on the results of simulation studies, it was suggested that the proposed approach was almost unbiased in the situation where the sample size exceeds 1000 and the change in sensitivity is monotonous. When the approach was applied to female nuclear worker data, a slight decreasing trend in breast cancer risk with increasing age at exposure was observed.The 4th International Symposium of the Network-type Joint Usage/Research Center for Radiation Disaster Medical Scienc

A Simulation Study of Radon and Thoron Discrimination Problem in Case-Control Studies

In most countries, radon is the dominant contributor among natural radiation sources to exposure dose of the general population. Numerous case-control studies of residential radon and lung cancer have been conducted using passive radon (Rn-222) detectors. These studies showed that radon may increase lung cancer risk, but most of them did not show a significant risk. Recently it was shown that the readings of passive radon detectors that do not employ thoron (Rn-220) discrimination techniques are affected by thoron. Therefore, we conducted a simulation study to evaluate the possible effect of thoron interference on estimation of radon-related lung cancer risk. Various assumptions were made based on the number of cases, matching ratio, baseline risk, true radon-related risk, distribution of radon and thoron concentrations, correlation between radon and thoron, and radon detectors. The results suggested that in certain circumstances thoron interference in radon measurements resulted in an approximately 90% downward bias. In addition, the magnitude of the bias increased as the geometric mean and geometric standard error of radon concentration decreased and those of thoron increased. In order to resolve this problem, it is necessary to use passive radon detectors with thoron discrimination techniques in epidemiological studies