Activated partial thromboplastin time‑based clot waveform analysis enables measurement of very low levels of factor IX activity in patients with severe hemophilia B

The precise measurement of very low levels of factor IX activity (FIX:C < 1 IU/dL) is essential for understanding clinical severity and risk of inhibitor development in patients with severe hemophilia B (Pw-SHB). However, such measurement sensitivity has not yet been achieved. We aimed to establish a measurement method using clot waveform analysis (CWA). Residual FIX:C by adding anti-FIX monoclonal antibody, FIX:C by adding recombinant (r)FIX to the commercial Pw-SHB plasmas, and FIX:C in our Pw-SHB were determined by CS-2000i™/CS-2400™, followed by analysis of CWA parameters. The presence of anti-FIX antibody in the commercial Pw-SHB plasmas significantly decreased coagulation potential compared to its absence. The addition of rFIX to these innate plasma samples produced significant changes in three parameters upon adding FIX:C at 0.1–1 IU/dL, supporting the presence of trace FIX:C in Pw-SHB. Therefore, appropriate FIX-depleted plasma containing minimum residual FIX:C was chosen from reference curves of FIX:C (0.01–1 IU/dL). Among patients with untreated Pw-SHB, two had FIX:C 0.6–0.7 IU/dL and two had lower than detectable levels using FIX-depleted plasma. One of the latter had detectable trough levels post-rFIX administration. In conclusion, CWA enabled measurement of very low levels of FIX:C using appropriate FIX-deficient plasma.博士（医学）・乙第1528号・令和4年12月22

High hydrostatic pressure induces slow contraction in mouse cardiomyocytes

Cardiomyocytes are contractile cells that regulate heart contraction. Ca2+ flux via Ca2+ channels activates actomyosin interactions, leading to cardiomyocyte contraction, which is modulated by physical factors (e.g., stretch, shear stress, and hydrostatic pressure). We evaluated the mechanism triggering slow contractions using a high-pressure microscope to characterize changes in cell morphology and intracellular Ca2+ concentration ([Ca2+]i) in mouse cardiomyocytes exposed to high hydrostatic pressures. We found that cardiomyocytes contracted slowly without an acute transient increase in [Ca2+]i, while a myosin ATPase inhibitor interrupted pressure-induced slow contractions. Furthermore, transmission electron microscopy showed that, although the sarcomere length was shortened upon the application of 20 MPa, this pressure did not collapse cellular structures such as the sarcolemma and sarcomeres. Our results suggest that pressure-induced slow contractions in cardiomyocytes are driven by the activation of actomyosin interactions without an acute transient increase in [Ca2+]i

A Novel RNA Synthesis Inhibitor, STK160830, Has Negligible DNA-Intercalating Activity for Triggering A p53 Response, and Can Inhibit p53-Dependent Apoptosis

RNA synthesis inhibitors and protein synthesis inhibitors are useful for investigating whether biological events with unknown mechanisms require transcription or translation; however, the dependence of RNA synthesis has been difficult to verify because many RNA synthesis inhibitors cause adverse events that trigger a p53 response. In this study, we screened a library containing 9600 core compounds and obtained STK160830 that shows anti-apoptotic effects in irradiated wild-type-p53-bearing human T-cell leukemia MOLT-4 cells and murine thymocytes. In many of the p53-impaired cells and p53-knockdown cells tested, STK160830 did not show a remarkable anti-apoptotic effect, suggesting that the anti-apoptotic activity is p53-dependent. In the expression analysis of p53, p53-target gene products, and reference proteins by immunoblotting, STK160830 down-regulated the expression of many of the proteins examined, and the downregulation correlated strongly with its inhibitory effect on cell death. mRNA expression analyses by qPCR and nascent RNA capture kit revealed that STK160830 showed a decreased mRNA expression, which was similar to that induced by the RNA synthesis inhibitor actinomycin D but differed to some extent. Furthermore, unlike other RNA synthesis inhibitors such as actinomycin D, p53 accumulation by STK160830 alone was negligible, and a DNA melting-curve analysis showed very weak DNA-intercalating activity, indicating that STK160830 is a useful inhibitor for RNA synthesis without triggering p53-mediated damage responses

Two distinct modes of DNMT1 recruitment ensure stable maintenance DNA methylation

Stable inheritance of DNA methylation is critical for maintaining differentiated phenotypes in multicellular organisms. We have recently identified dual mono-ubiquitylation of histone H3 (H3Ub2) by UHRF1 as an essential mechanism to recruit DNMT1 to chromatin. Here, we show that PCNA-associated factor 15 (PAF15) undergoes UHRF1-dependent dual mono-ubiquitylation (PAF15Ub2) on chromatin in a DNA replication-coupled manner. This event will, in turn, recruit DNMT1. During early S-phase, UHRF1 preferentially ubiquitylates PAF15, whereas H3Ub2 predominates during late S-phase. H3Ub2 is enhanced under PAF15 compromised conditions, suggesting that H3Ub2 serves as a backup for PAF15Ub2. In mouse ES cells, loss of PAF15Ub2 results in DNA hypomethylation at early replicating domains. Together, our results suggest that there are two distinct mechanisms underlying replication timing-dependent recruitment of DNMT1 through PAF15Ub2 and H3Ub2, both of which are prerequisite for high fidelity DNA methylation inheritance

The Clinical Application of Hydrogen as a Medical Treatment

In recent years, it has become evident that molecular hydrogen is a particularyl effective treatment for various disease models such as ischemia-reperfusion injury; as a result, research on hydrogen has progressed rapidly. Hydrogen has been shown to be effective not only through intake as a gas, but also as a liquid medication taken orally, intravenously, or locally. Hydrogenʼs effectiveness is thus multifaceted. Herein we review the recent research on hydrogen-rich water, and we examine the possibilities for its clinical application. Now that hydrogen is in the limelight as a gaseous signaling molecule due to its potential ability to inhibit oxidative stress signaling, new research developments are highly anticipated

チガクケイ センモンガッキョウカイ ニヨル イッパン シミン オ タイショウ ト シタ アウトリーチ ジュンケン ノ ジッセン ホウコク

日本第四紀学会では，徳島県で開催された2011年の研究大会にあわせて，「100万年の東四国を探る」というテーマで親子を含む一般市民を対象にした巡検を行った. それを「アウトリーチ巡検」と呼び，全部で52名の参加者があった. アンケート調査によれば，参加者はアウトリーチ巡検を肯定的にとらえており，今後もアウトリーチ巡検の実施を希望していた. 今後，日本地学教育学会と地学に関係する研究系の学協会とが連携して，このようなアウトリーチ巡検を学会の学術大会にあわせて実施することが期待される

Joint Asymptotic Properties of Stopping Times and Sequential Estimators for Stationary First-order Autoregressive Models

Currently, because online data is abundant and can be collected more easily , people often face the problem of making correct statistical decisions as soon as possible. If the online data is sequentially available, sequential analysis is appropriate for handling such a problem. We consider the joint asymptotic properties of stopping times and sequential estimators for stationary first-order autoregressive (AR(1)) processes under independent and identically distributed errors with zero mean and finite variance. Using the stopping times introduced by Lai and Siegmund (1983) for AR(1), we investigate the joint asymptotic properties of the stopping times, the sequential least square estimator (LSE), and the estimator of σ². The functional central limit theorem for nonlinear ergodic stationary processes is crucial for obtaining our main results with respect to their asymptotic properties. We found that the sequential least square estimator and stopping times exhibit joint asymptotic normality. When σ² is estimated, the joint limiting distribution degenerates and the asymptotic variance of the stopping time is strictly smaller than that of the stopping time with a known σ²