Approach to the asymptomatic patients with Brugada syndrome

Brugada syndrome is an arrhythmogenic disease characterized by an ECG pattern of coved-type ST segment elevation in the right precordial leads and an increased risk of sudden cardiac death (SCD) as a result of polymorphic ventricular tachyarrhythmia or ventricular fibrillation (VF). Data from large patient studies and a meta-analysis of previous reports have shown that patients with a history of syncope or SCD and a spontaneous type 1 Brugada type ECG are at high risk for SCD. However, risk stratification of asymptomatic patients with Brugada type ECG is still a challenge. In particular, the use of electrophysiological study (EPS) for risk stratification remains controversial. Although some investigators have reported the possibility of use of EPS for distinguishing between high- and low-risk patients with Brugada type ECG, no precise predictor of risk for SCD in asymptomatic patients has yet been determined. The approach to treatment of these patients is thus still unclear. Large clinical prospective studies with uniform diagnostic criteria and protocols for EPS as well as extended follow-up periods of over ten years are required for prediction of SCD

Strength-enhanced Sn–In low-temperature alloy with surface-modified ZrO₂ nanoparticle addition

Low-temperature packaging is essential for the widespread use of flexible electronic devices, and Sn–In eutectic alloys have attracted considerable attention because of their low melting temperatures. However, these alloys have a lower strength compared with other types of solder alloys. This study aimed to investigate the effect of adding nanoparticles on the mechanical strength of Sn–In eutectic alloys while keeping their melting temperature unchanged. ZrO₂ nanoparticles coated with NiO (NiO/ZrO₂ nanoparticles) were utilized to strengthen Sn–In eutectic alloys with a high dispersity. Sn–In composite alloys reinforced with NiO/ZrO₂ nanoparticles were fabricated, and tensile strength evaluation and microstructure observations were conducted. The experimental results showed that the addition of nanoparticles to the Sn–In eutectic alloys did not change their melting behavior. The tensile strength of the Sn–In composite alloys reinforced with NiO/ZrO₂ nanoparticles increased by up to 35.6%, which was attributed to grain refinement and dispersion strengthening. Even after thermal aging at 60 ºC, the Sn–In composite alloys reinforced with NiO/ZrO₂ nanoparticles showed a 1.11 times higher ultimate tensile strength than that of the non-aged, non-reinforced eutectic alloy, despite grain coarsening. This was attributed to the contribution of dispersion strengthening. These results indicate that the addition of NiO/ZrO₂ nanoparticles is an effective method to improve the strength of low-melting-temperature alloys.The version of record of this article, first published in Journal of Materials Science: Materials in Electronics, is available online at Publisher’s website: https://doi.org/10.1007/s10854-023-11344-

Rarefied gas flows through a curved channel: Application of a diffusion-type equation

Rarefied gas flows through a curved two-dimensional channel, caused by a pressure or a temperature gradient, are investigated numerically by using a macroscopic equation of convection-diffusion type. The equation, which was derived systematically from the Bhatnagar–Gross–Krook model of the Boltzmann equation and diffuse-reflection boundary condition in a previous paper [K. Aoki et al., “A diffusion model for rarefied flows in curved channels, ” Multiscale Model. Simul. 6, 1281 (2008)], is valid irrespective of the degree of gas rarefaction when the channel width is much shorter than the scale of variations of physical quantities and curvature along the channel. Attention is also paid to a variant of the Knudsen compressor that can produce a pressure raise by the effect of the change of channel curvature and periodic temperature distributions without any help of moving parts. In the process of analysis, the macroscopic equation is (partially) extended to the case of the ellipsoidal-statistical model of the Boltzmann equation

The effects of nifekalant hydrochloride on the spatial dispersion of repolarization after direct current defibrillation in patients with oral amiodarone and β-blocker therapy

AbstractBackgroundAlthough nifekalant hydrochloride (NIF) has been demonstrated to suppress ventricular tachyarrhythmias, especially electrical storms, the mechanism by which it does so is still unclear. We examined the effects of NIF on the spatial dispersion of repolarization (SDR) after implantable cardioverter-defibrillator (ICD) shock.Methods and ResultsIn 35 patients with oral amiodarone and β-blocker therapy, and an ICD, we recorded the 87-lead electrocardiogram during sinus rhythm (CONTROL-1 group) under general anesthesia, and just after the termination of induced ventricular fibrillation (VF) by ICD shock, with or without NIF administration. In all recordings, the corrected QT interval (QTc) was measured in each lead. The dispersion of QTc (QTc-D; maximum QTc minus minimum QTc) was also measured. Compared with that in the CONTROL-1 group, the QTc-D exhibited significant deterioration after ICD shock (61±14 and 90±19ms1/2, respectively; p<0.05). However, after the termination of induced VF by ICD shock with NIF administration, the QTc-D did not differ significantly from that in the CONTROL-1 group (63±20 and 61±14ms1/2, respectively).ConclusionsNIF suppressed the deterioration of the SDR after ICD shock. This might be one of the mechanisms by which NIF suppresses recurrence of ventricular tachyarrhythmia just after ICD shock in patients with oral amiodarone and β-blocker therapy

Interferometer design of the KAGRA gravitational wave detector

KAGRA is a cryogenic interferometric gravitational-wave detector being constructed at the underground site of Kamioka mine in Gifu prefecture, Japan. We performed an optimization of the interferomter design, to achieve the best sensitivity and a stable operation, with boundary conditions of classical noises and under various practical constraints, such as the size of the tunnel or the mirror cooling capacity. Length and alignment sensing schemes for the robust control of the interferometer are developed. In this paper, we describe the detailed design of the KAGRA interferometer as well as the reasoning behind design choices

Possible impact of ADRB3 Trp64Arg polymorphism on BMI in patients with schizophrenia

Background: The beta 3-adrenoceptor (ADRB3) gene Trp64Arg polymorphism has been shown to be associated with obesity as well as type 2 diabetes and cardiovascular disease. The incidence of overweight and the risks of type 2 diabetes and cardiovascular disease are also increased in major depression and schizophrenia. We hypothesized that the Trp64Arg polymorphism may be associated with increased risk of schizophrenia and depression. Methods: The Trp64Arg was genotyped in 504 patients with schizophrenia, 650 with major depressive disorder (MOD), and 1170 healthy controls. Of these participants, body mass index (BMI) data were available for 125 patients with schizophrenia, 219 with MDD, and 261 controls. Results: No significant difference in genotype or allele distribution was found across the diagnostic groups. No significant difference in BMI was observed between the Arg allele carriers and the non-carriers in the MDD and the control groups. However, patients with schizophrenia carrying the Arg allele had significantly higher BMI (Mean (SD): Arg carriers: 26.5 (6.9), Arg non-carriers: 23.8 (4.3); P=0.019) and a higher rate of being overweight (BMI of 25 or more) compared to their counterparts (Trp/Trp group) (% overweight (SE): Arg carriers: 52.3 (7.5), Arg non-carriers: 32.1 (5.2); P=0.027). Conclusions: We obtained no evidence for the association of ADRB3 Trp64Arg with the development of MDD or schizophrenia. However, the Arg allele was found to be associated with higher BMI and being overweight in patients with schizophrenia. This may imply that genotyping ADRB3 is of clinical use to detect schizophrenic individuals at risk for developing obesity.ArticlePROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY. 38(2):341-344 (2012)journal articl

Possible association between Interleukin-1beta gene and schizophrenia in a Japanese population

Background: Several lines of evidence have implicated the pro-inflammatory cytokine interleukin-1beta (IL-1 beta) in the etiology of schizophrenia. Although a number of genetic association studies have been reported, very few have systematically examined gene-wide tagging polymorphisms. Methods: A total of 533 patients with schizophrenia (302 males: mean age +/- standard deviation 43.4 +/- 13.0 years; 233 females; mean age 44.8 +/- 15.3 years) and 1136 healthy controls (388 males: mean age 44.6 +/- 17.3 years; 748 females; 46.3 +/- 15.6 years) were recruited for this study. All subjects were biologically unrelated Japanese individuals. Five tagging polymorphisms of IL-1 beta gene (rs2853550, rs1143634, rs1143633, rs1143630, rs16944) were examined for association with schizophrenia. Results: Significant difference in allele distribution was found between patients with schizophrenia and controls for rs1143633 (P = 0.0089). When the analysis was performed separately in each gender, significant difference between patients and controls in allele distribution of rs1143633 was observed in females (P = 0.0073). A trend towards association was also found between rs16944 and female patients with schizophrenia (P = 0.032). Conclusions: The present study shows the first evidence that the IL-1 beta gene polymorphism rs1143633 is associated with schizophrenia susceptibility in a Japanese population. The results suggest the possibility that the influence of IL-1 beta gene variations on susceptibility to schizophrenia may be greater in females than in males. Findings of the present study provide further support for the role of IL-1 beta in the etiology of schizophrenia

網膜へのレーザー凝固により惹起される脈絡膜新生血管はヘッジホッグシグナル系因子を発現する。

Choroidal neovascularization is one of the major pathological changes in age-related macular degeneration, which causes devastating blindness in the elderly population. The molecular mechanism of choroidal neovascularization has been under extensive investigation, but is still an open question. We focused on sonic hedgehog signaling, which is implicated in angiogenesis in various organs. Laser-induced injuries to the mouse retina were made to cause choroidal neovascularization. We examined gene expression of sonic hedgehog, its receptors (patched1, smoothened, cell adhesion molecule down-regulated by oncogenes (Cdon) and biregional Cdon-binding protein (Boc)) and downstream transcription factors (Gli1-3) using real-time RT-PCR. At seven days after injury, mRNAs for Patched1 and Gli1 were upregulated in response to injury, but displayed no upregulation in control retinas. Immunohistochemistry revealed that Patched1 and Gli1 proteins were localized to CD31-positive endothelial cells that cluster between the wounded retina and the pigment epithelium layer. Treatment with the hedgehog signaling inhibitor cyclopamine did not significantly decrease the size of the neovascularization areas, but the hedgehog agonist purmorphamine made the areas significantly larger than those in untreated retina. These results suggest that the hedgehog-signaling cascade may be a therapeutic target for age-related macular degeneration.博士（医学）・甲第653号・平成28年7月8日Copyright © 2016 The Japan Society of Histochemistry and Cytochemistry（日本組織細胞化学会）J-STAGEへのリンク：http://doi.org/10.1267/ahc.1503