A computational framework for bioimaging simulation

Using bioimaging technology, biologists have attempted to identify and document analytical interpretations that underlie biological phenomena in biological cells. Theoretical biology aims at distilling those interpretations into knowledge in the mathematical form of biochemical reaction networks and understanding how higher level functions emerge from the combined action of biomolecules. However, there still remain formidable challenges in bridging the gap between bioimaging and mathematical modeling. Generally, measurements using fluorescence microscopy systems are influenced by systematic effects that arise from stochastic nature of biological cells, the imaging apparatus, and optical physics. Such systematic effects are always present in all bioimaging systems and hinder quantitative comparison between the cell model and bioimages. Computational tools for such a comparison are still unavailable. Thus, in this work, we present a computational framework for handling the parameters of the cell models and the optical physics governing bioimaging systems. Simulation using this framework can generate digital images of cell simulation results after accounting for the systematic effects. We then demonstrate that such a framework enables comparison at the level of photon-counting units.Comment: 57 page

低インスリン血症は、非糖尿病急性非代償性心不全患者において、全死亡、心血管死の独立した予後予測因子である

Background Insulin beneficially affects myocardial functions during myocardial ischemia. It increases glucose-derived ATP production, decreases oxygen consumption, suppresses apoptosis of cardiomyocytes, and promotes the survival of cardiomyocytes. Patients with chronic heart failure generally have high insulin resistance, which is correlated with poor outcomes. The role of insulin in acute decompensated heart failure (ADHF) remains unclear. This study aimed to investigate the prognostic value of serum insulin level at the time of admission for long-term outcomes in patients with ADHF. Methods and Results We enrolled 1074 consecutive patients who were admitted to our department for ADHF. Of these 1074 patients, we studied the impact of insulin on the prognosis of ADHF in 241 patients without diabetes mellitus. The patients were divided into groups according to low, intermediate, and high tertiles of serum insulin levels. Primary end points were all-cause death and cardiovascular death. During a mean follow-up of 21.8 months, 71 all-cause deaths and 38 cardiovascular deaths occurred. Kaplan-Meier analysis showed that all-cause and cardiovascular mortality was significantly higher in the low-insulin group than those in the intermediate- and high-insulin groups (log-rank P=0.0046 and P=0.038, respectively). Moreover, according to the multivariable analysis, low serum insulin was an independent predictor of all-cause and cardiovascular mortality (hazard ratio, 2.37 [95% CI, 1.24-4.65; P=0.009] and 2.94 [95% CI, 1.12-8.19; P=0.028], respectively). Conclusions Low serum insulin levels were associated with increased risk of all-cause and cardiovascular death in ADHF patients without diabetes mellitus.博士（医学）・甲第808号・令和4年3月15日© 2020 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License(https://creativecommons.org/licenses/by-nc/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes

日本における非代償性急性心不全患者の30日および90日以内の心不全再入院の発生率と臨床的意義 : NARA-HF研究より

Background: Countermeasure development for early rehospitalization for heart failure (re-HHF) is an urgent and important issue in Western countries and Japan.Methods and Results:Of 1,074 consecutive NARA-HF study participants with acute decompensated HF admitted to hospital as an emergency between January 2007 and December 2016, we excluded 291 without follow-up data, who died in hospital, or who had previous HF-related hospitalizations, leaving 783 in the analysis. During the median follow-up period of 895 days, 241 patients were re-admitted for HF. The incidence of re-HHF was the highest within the first 30 days of discharge (3.3% [26 patients]) and remained high until 90 days, after which it decreased sharply. Within 90 days of discharge, 63 (8.0%) patients were re-admitted. Kaplan-Meier analysis revealed that patients with 90-day re-HHF had worse prognoses than those without 90-day re-HHF in terms of all-cause death (hazard ratio [HR] 2.321, 95% confidence interval [CI] 1.654-3.174; P<0.001) and cardiovascular death (HR 3.396, 95% CI 2.153-5.145; P<0.001). Multivariate analysis indicated that only male sex was an independent predictor of 90-day re-HHF. Conclusions: The incidence of early re-HHF was lower in Japan than in Western countries. Its predictors are not related to the clinical factors of HF, indicating that a new comprehensive approach might be needed to prevent early re-HHF.博士（医学）・甲第735号・令和2年3月16日日本循環器学会の許諾を得て登録（2020年9月2日付）ジャーナル公式サイト（日本循環器学会HP内）：https://www.j-circ.or.jp/journal/公開サイト（J-STAGE）：https://www.jstage.jst.go.jp/browse/circj

急性心不全における退院時の尿素窒素分画排泄率の予後判定への有用性

Background Maintaining euvolemia is crucial for improving prognosis in acute decompensated heart failure (ADHF). Although fractional excretion of urea nitrogen (FEUN) is used as a body fluid volume index in patients with acute kidney injury, the clinical impact of FEUN in patients with ADHF remains unclear. This study aimed to investigate whether FEUN can determine the long-term prognosis in patients with ADHF. Methods and Results We retrospectively identified 466 patients with ADHF who had FEUN measured at discharge between April 2011 and December 2018. The primary endpoint was post-discharge all-cause death. Patients were divided into two groups according to a FEUN cut-off value of 35%, commonly used in pre-renal failure. The FEUN <35% (low-FEUN) group included 224 patients (48.1%), and the all-cause mortality rate for the total cohort was 37.1%. The log-rank test revealed that the low-FEUN group had a significantly higher rate of all-cause death compared to the FEUN equal to or greater than 35% (high-FEUN) group (P<0.001). Multivariate Cox proportional hazards model analysis revealed that low-FEUN was associated with post-discharge all-cause death, independently of other heart failure risk factors (hazard ratio, 1.467; 95% CI, 1.030-2.088, P=0.033). The risk of low-FEUN compared to high-FEUN in post-discharge all-cause death was consistent across all subgroups; however, the effects tended to be modified by renal function (threshold: 60 mL/min/1.73 m2, interaction P=0.069). Conclusions Our study suggests that FEUN may be a novel surrogate marker of volume status in patients with ADHF requiring diuretics.博士（医学）・甲第814号・令和4年3月15日Copyright © 2021 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License(https://creativecommons.org/licenses/by-nc-nd/4.0/), which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made

A three-component monooxygenase from Rhodococcus wratislaviensis may expand industrial applications of bacterial enzymes

地球外有機化合物に対する微生物代謝の解明から全く新規な酵素系を発見 --生命分子進化の理解や産業応用に期待--. 京都大学プレスリリース. 2021-01-20.The high-valent iron-oxo species formed in the non-heme diiron enzymes have high oxidative reactivity and catalyze difficult chemical reactions. Although the hydroxylation of inert methyl groups is an industrially promising reaction, utilizing non-heme diiron enzymes as such a biocatalyst has been difficult. Here we show a three-component monooxygenase system for the selective terminal hydroxylation of α-aminoisobutyric acid (Aib) into α-methyl-D-serine. It consists of the hydroxylase component, AibH1H2, and the electron transfer component. Aib hydroxylation is the initial step of Aib catabolism in Rhodococcus wratislaviensis C31-06, which has been fully elucidated through a proteome analysis. The crystal structure analysis revealed that AibH1H2 forms a heterotetramer of two amidohydrolase superfamily proteins, of which AibHm2 is a non-heme diiron protein and functions as a catalytic subunit. The Aib monooxygenase was demonstrated to be a promising biocatalyst that is suitable for bioprocesses in which the inert C–H bond in methyl groups need to be activated

僧帽弁閉鎖不全症を伴うまたは伴わない非代償性急性心不全患者の予後に心房細動が与える影響

Background: Atrial fibrillation (AF) and mitral regurgitation (MR) are frequently combined in patients with heart failure (HF). However, the effect of AF on the prognosis of patients with HF and MR remains unknown. Methods and Results: We studied 867 patients (mean age 73 years; 42.7% female) with acute decompensated HF (ADHF) in the NARA-HF registry. Patients were divided into 4 groups based on the presence or absence of AF and MR at discharge. Patients with severe MR were excluded. The primary endpoint was the composite of cardiovascular (CV) death and HF-related readmission. During the median follow-up of 621 days, 398 patients (45.9%) reached the primary endpoint. In patients with MR, AF was associated with a higher incidence of the primary endpoint regardless of left ventricular function; however, in patients without MR, AF was not associated with CV events. Cox multivariate analyses showed that the incidence of CV events was significantly higher in patients with AF and MR than in patients with MR but without AF (hazard ratio 1.381, P=0.036). Similar findings were obtained in subgroup analysis of patients with AF and only mild MR. Conclusions: The present study demonstrated that AF is associated with poor prognosis in patients with ADHF with mild to moderate MR, but not in those without MR.博士（医学）・甲第799号・令和3年9月29日© 2021, THE JAPANESE CIRCULATION SOCIETY This article is licensed under a Creative Commons [Attribution-NonCommercial-NoDerivatives 4.0 International] license. https://creativecommons.org/licenses/by-nc-nd/4.0

新刊紹介

p.110, pp.131-132, pp.153-154, p.164, p.17

Organ accumulation and carcinogenicity of highly dispersed multi-walled carbon nanotubes administered intravenously in transgenic rasH2 mice

Purpose: Multiwalled carbon nanotubes (MWCNTs) have been known to enter the circulatory system via the lungs from inhalation exposure; however, its carcinogenicity and subsequent accumulation in other organs have not been adequately reported in the literature. Moreover, the safety of MWCNTs as a biomaterial has remained a matter of debate, particularly when the material enters the circulatory system. To address these problems, we used carcinogenic rasH2 transgenic mice to intravenously administer highly dispersed MWCNTs and to evaluate their carcinogenicity and accumulation in the organs. Methods: Two types of MWCNTs (thin-and thick-MWCNTs) were intravenously administered at a high dose (approximately 0.7 mg per kg body weight) and low dose (approximately 0.07 mg per kg body weight). Results: MWCNTs showed pancreatic accumulation in 3.2% of mice administered with MWCNTs, but there was no accumulation in other organs. In addition, there was no significant difference in the incidence of tumor among the four MWCNTs-administered groups compared to the vehicle group without MWCNTs administration. Blood tests revealed elevated levels in mean red blood cell volume and mean red blood cell hemoglobin level for the MWCNTs-administered group, in addition to an increase in eotaxin. Conclusion: The present study demonstrated that the use of current technology to sufficiently disperse MWCNTs resulted in minimal organ accumulation with no evidence of carcinogenicity.ArticleINTERNATIONAL JOURNAL OF NANOMEDICINE. 14:6465-6480 (2019)journal articl