30 research outputs found

    Multi-DOF precision positioning methodology using two-axis Hall-effect sensors

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    A novel sensing methodology using two-axis Hall-effect sensors is proposed, where the absolute positioning of a device atop any magnet matrix is possible. This methodology has the capability of micrometer-order positioning resolution as well as unrestricted translational and rotational range in planar 3-DOF (degree-of-freedom) motions, with potential capability of measuring all 6-DOF motions. This research presents the methodology and preliminary experimental results of 3-DOF planar motion measurements atop a Halbach magnet matrix using two sets of two-axis Hall-effect sensors. Analysis of the Halbach magnet matrix is presented to understand the generated magnetic field. The algorithm uses the Gaussian least squares differential correction (GLSDC) algorithm to estimate the relative position and orientation from the Hall-effect sensor measurements. A recursive discrete-time Kalman filter (DKF) is used in combination with the GLSDC to obtain optimal estimates of position and orientation, as well as additional estimates of velocity and angular velocity, which we can use to design a multivariable controller. The sensor and its algorithm is implemented to a magnetic levitation (maglev) stage positioned atop a Halbach magnet matrix. Preliminary experimental results show its position resolution capability of less than 10 µm and capable of sensing large rotations. Controllers were designed to close the control loop for the three planar degrees of freedom motion using the GLSDC outputs at a sampling frequency of 800 Hz on a Pentek 4284 digital signal processor (DSP). Calibration was done by comparing the laser interferometers and the GLSDCÂs outputs to improve the positioning accuracy

    MEG Source Imaging and Group Analysis Using VBMEG

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    Variational Bayesian Multimodal EncephaloGraphy (VBMEG) is a MATLAB toolbox that estimates distributed source currents from magnetoencephalography (MEG)/electroencephalography (EEG) data by integrating functional MRI (fMRI) (https://vbmeg.atr.jp/). VBMEG also estimates whole-brain connectome dynamics using anatomical connectivity derived from a diffusion MRI (dMRI). In this paper, we introduce the VBMEG toolbox and demonstrate its usefulness. By collaborating with VBMEG's tutorial page (https://vbmeg.atr.jp/docs/v2/static/vbmeg2_tutorial_neuromag.html), we show its full pipeline using an open dataset recorded by Wakeman and Henson (2015). We import the MEG data and preprocess them to estimate the source currents. From the estimated source currents, we perform a group analysis and examine the differences of current amplitudes between conditions by controlling the false discovery rate (FDR), which yields results consistent with previous studies. We highlight VBMEG's characteristics by comparing these results with those obtained by other source imaging methods: weighted minimum norm estimate (wMNE), dynamic statistical parametric mapping (dSPM), and linearly constrained minimum variance (LCMV) beamformer. We also estimate source currents from the EEG data and the whole-brain connectome dynamics from the MEG data and dMRI. The observed results indicate the reliability, characteristics, and usefulness of VBMEG

    Corticosterone Induces Rapid Spinogenesis via Synaptic Glucocorticoid Receptors and Kinase Networks in Hippocampus

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    BACKGROUND: Modulation of dendritic spines under acute stress is attracting much attention. Exposure to acute stress induces corticosterone (CORT) secretion from the adrenal cortex, resulting in rapid increase of CORT levels in plasma and the hippocampus. METHODOLOGY/PRINCIPAL FINDINGS: Here we demonstrated the mechanisms of rapid effect (∼1 h) of CORT on the density and morphology of spines by imaging neurons in adult male rat hippocampal slices. The application of CORT at 100-1000 nM induced a rapid increase in the density of spines of CA1 pyramidal neurons. The density of small-head spines (0.2-0.4 µm) was increased even at low CORT levels (100-200 nM). The density of middle-head spines (0.4-0.5 µm) was increased at high CORT levels between 400-1000 nM. The density of large-head spines (0.5-1.0 µm) was increased only at 1000 nM CORT. Co-administration of RU486, an antagonist of glucocorticoid receptor (GR), abolished the effect of CORT. Blocking a single kinase, such as MAPK, PKA, PKC or PI3K, suppressed CORT-induced enhancement of spinogenesis. Blocking NMDA receptors suppressed the CORT effect. CONCLUSIONS/SIGNIFICANCE: These results imply that stress levels of CORT (100-1000 nM) drive the spinogenesis via synaptic GR and multiple kinase pathways

    Lower In-Hospital Mortality With Beta-Blocker Use at Admission in Patients With Acute Decompensated Heart Failure

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    [Background] It remains unclear whether beta‐blocker use at hospital admission is associated with better in‐hospital outcomes in patients with acute decompensated heart failure. [Methods and Results] We evaluated the factors independently associated with beta‐blocker use at admission, and the effect of beta‐blocker use at admission on in‐hospital mortality in 3817 patients with acute decompensated heart failure enrolled in the Kyoto Congestive Heart Failure registry. There were 1512 patients (39.7%) receiving, and 2305 patients (60.3%) not receiving beta‐blockers at admission for the index acute decompensated heart failure hospitalization. Factors independently associated with beta‐blocker use at admission were previous heart failure hospitalization, history of myocardial infarction, atrial fibrillation, cardiomyopathy, and estimated glomerular filtration rate <30 mL/min per 1.73 m2. Factors independently associated with no beta‐blocker use were asthma, chronic obstructive pulmonary disease, lower body mass index, dementia, older age, and left ventricular ejection fraction <40%. Patients on beta‐blockers had significantly lower in‐hospital mortality rates (4.4% versus 7.6%, P<0.001). Even after adjusting for confounders, beta‐blocker use at admission remained significantly associated with lower in‐hospital mortality risk (odds ratio, 0.41; 95% CI, 0.27–0.60, P<0.001). Furthermore, beta‐blocker use at admission was significantly associated with both lower cardiovascular mortality risk and lower noncardiovascular mortality risk. The association of beta‐blocker use with lower in‐hospital mortality risk was relatively more prominent in patients receiving high dose beta‐blockers. The magnitude of the effect of beta‐blocker use was greater in patients with previous heart failure hospitalization than in patients without (P for interaction 0.04). [Conclusions] Beta‐blocker use at admission was associated with lower in‐hospital mortality in patients with acute decompensated heart failure

    Appetite loss at discharge from acute decompensated heart failure: Observation from KCHF registry

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    OBJECTIVE: The complex link between nutritional status, protein and lipid synthesis, and immunity plays an important prognostic role in patients with heart failure. However, the association between appetite loss at discharge and long-term outcome remains unclear. METHODS: The Kyoto Congestive Heart Failure registry is a prospective cohort study that enrolled consecutive patients hospitalized for acute decompensated heart failure (ADHF) in Japan. We assessed 3528 patients alive at discharge, and for whom appetite and follow-up data were available. We compared one-year clinical outcomes in patients with and without appetite loss at discharge. RESULTS: In the multivariable logistic regression analysis using 19 clinical and laboratory factors with P value 1.0mg/dL (OR: 1.49, 95%CI: 1.04-2.14, P = 0.03), and presence of edema at discharge (OR: 4.30, 95%CI: 2.99-6.22, P<0.001) were associated with an increased risk of appetite loss at discharge, whereas ambulatory status (OR: 0.57, 95%CI: 0.39-0.83, P = 0.004) and the use of ACE-I/ARB (OR: 0.70, 95% CI: 0.50-0.98, P = 0.04) were related to a decreased risk in the presence of appetite loss. The cumulative 1-year incidence of all-cause death (primary outcome measure) was significantly higher in patients with appetite loss than in those without appetite loss (31.0% vs. 15.0%, P<0.001). The excess adjusted risk of appetite loss relative to no appetite loss remained significant for all-cause death (hazard ratio (HR): 1.63, 95%CI: 1.29-2.07, P<0.001). CONCLUSIONS: Loss of appetite at discharge was associated with worse 1-year mortality in patients with ADHF. Appetite is a simple, reliable, and useful subjective marker for risk stratification of patients with ADHF

    Current use of inotropes according to initial blood pressure and peripheral perfusion in the treatment of congestive heart failure: findings from a multicentre observational study

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    OBJECTIVES: Current guidelines restrict the use of inotropes for the treatment for heart failure (HF) unless the patients are hypotensive or hypoperfused because of safety concerns. This study sought to characterise the contemporary real-world use of inotropes and associated long-term outcomes according to systolic blood pressure (sBP) and perfusion status. DESIGN: A multicentre prospective cohort study. SETTING: This study was nested from the Kyoto Congestive Heart Failure registry, which included consecutive Japanese patients admitted for HF. PARTICIPANTS: We categorised 3995 patients into two groups: sBP ≥90 mm Hg and warm profile group, and sBP <90 mm Hg or cold profile group. In each group, patients were stratified across the use of inotropes within 24 hours of hospital presentation. PRIMARY AND SECONDARY OUTCOMES: The primary outcome was all-cause death throughout follow-up. Secondary outcomes included cardiovascular death throughout follow-up, all-cause death during index hospitalisation and after discharge, and HF hospitalisation. RESULTS: A total of 793 patients (20%) presented with sBP <90 mm Hg or cold profile, whereas 3202 patients had sBP ≥90 mm Hg and warm profile; 276 patients (35%) in the sBP <90 mm Hg/cold group and 312 patients (10%) in the sBP ≥90 mm Hg/warm group received initial inotropic treatment. Adjusted excess risk of inotrope use relative to no inotrope for the primary outcome measure was significant in the sBP ≥90 mm Hg/warm group (adjusted HR), 1.36; 95% CI 1.09 to 1.72, p=0.006) but not in the sBP <90 mm Hg/cold group (adjusted HR, 1.28, 95% CI 0.96 to 1.69, p=0.09). Risk for postdischarge all-cause death and HF hospitalisation was not significantly different between the patients with inotropes and no inotropes in both groups. CONCLUSION: Inotrope use in the absence of hypotension and hypoperfusion is still common, but associated with a worse long-term prognosis. TRIAL REGISTRATION NUMBER: UMIN000015238

    Tricuspid regurgitation in elderly patients with acute heart failure: insights from the KCHF registry

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    AIMS: Several studies demonstrated that tricuspid regurgitation (TR) is associated with poor clinical outcomes. However, data on patients with TR who experienced acute heart failure (AHF) remains scarce. The purpose of this study is to evaluate the association between TR and clinical outcomes in patients admitted with AHF, using a large-scale Japanese AHF registry. METHODS AND RESULTS: The current study population consisted of 3735 hospitalized patients due to AHF in the Kyoto Congestive Heart Failure (KCHF) registry. TR grades were assessed according to the routine clinical practice at each participating centre. We compared the baseline characteristics and outcomes according to the severity of TR. The primary outcome was all-cause death. The secondary outcome was hospitalization for heart failure (HF). The median age of the entire study population was 80 (interquartile range: 72-86) years. One thousand two hundred five patients (32.3%) had no TR, while mild, moderate, and severe TR was found in 1537 patients (41.2%), 776 patients (20.8%), and 217 patients (5.8%), respectively. Pulmonary hypertension, significant mitral regurgitation, and atrial fibrillation/flutter were strongly associated with the development of moderate/severe of TR, while left ventricular ejection fraction <50% was inversely associated with it. Among 993 patients with moderate/severe TR, the number of patients who underwent surgical intervention for TR within 1 year was only 13 (1.3%). The median follow-up duration was 475 (interquartile range: 365-653) days with 94.0% follow-up at 1 year. As the TR severity increased, the cumulative 1 year incidence of all-cause death and HF admission proportionally increased ([14.8%, 20.3%, 23.4%, 27.0%] and [18.9%, 23.0%, 28.5%, 28.4%] in no, mild, moderate, and severe TR, respectively). Compared with no TR, the adjusted risks of patients with mild, moderate, and severe TR were significant for all-cause death (hazard ratio [95% confidence interval]: 1.20 [1.00-1.43], P = 0.0498, 1.32 [1.07-1.62], P = 0.009, and 1.35 [1.00-1.83], P = 0.049, respectively), while those were not significant for hospitalization for HF (hazard ratio [95% confidence interval]: 1.16 [0.97-1.38], P = 0.10, 1.19 [0.96-1.46], P = 0.11, and 1.20 [0.87-1.65], P = 0.27, respectively). The higher adjusted HRs of all the TR grades relative to no TR were significant for all-cause death in patients aged <80 years, but not in patients aged ≥80 years with significant interaction. CONCLUSIONS: In a large Japanese AHF population, the grades of TR could successfully stratify the risk of all-cause death. However, the association of TR with mortality was only modest and attenuated in patients aged 80 or more. Further research is warranted to evaluate how to follow up and manage TR in this elderly population

    Public assistance in patients with acute heart failure: a report from the KCHF registry

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    AIMS: There is a scarcity of data on the post-discharge prognosis in acute heart failure (AHF) patients with a low-income but receiving public assistance. The study sought to evaluate the differences in the clinical characteristics and outcomes between AHF patients receiving public assistance and those not receiving public assistance. METHODS AND RESULTS: The Kyoto Congestive Heart Failure registry was a physician-initiated, prospective, observational, multicentre cohort study enrolling 4056 consecutive patients who were hospitalized due to AHF for the first time between October 2014 and March 2016. The present study population consisted of 3728 patients who were discharged alive from the index AHF hospitalization. We divided the patients into two groups, those receiving public assistance and those not receiving public assistance. After assessing the proportional hazard assumption of public assistance as a variable, we constructed multivariable Cox proportional hazard models to estimate the risk of the public assistance group relative to the no public assistance group. There were 218 patients (5.8%) receiving public assistance and 3510 (94%) not receiving public assistance. Patients in the public assistance group were younger, more frequently had chronic coronary artery disease, previous heart failure hospitalizations, current smoking, poor medical adherence, living alone, no occupation, and a lower left ventricular ejection fraction than those in the no public assistance group. During a median follow-up of 470 days, the cumulative 1 year incidences of all-cause death and heart failure hospitalizations after discharge did not differ between the public assistance group and no public assistance group (13.3% vs. 17.4%, P = 0.10, and 28.3% vs. 23.8%, P = 0.25, respectively). After adjusting for the confounders, the risk of the public assistance group relative to the no public assistance group remained insignificant for all-cause death [hazard ratio (HR), 0.97; 95% confidence interval (CI), 0.69-1.32; P = 0.84]. Even after taking into account the competing risk of all-cause death, the adjusted risk within 180 days in the public assistance group relative to the no public assistance group remained insignificant for heart failure hospitalizations (HR, 0.93; 95% CI, 0.64-1.34; P = 0.69), while the adjusted risk beyond 180 days was significant (HR, 1.56; 95% CI, 1.07-2.29; P = 0.02). CONCLUSIONS: The AHF patients receiving public assistance as compared with those not receiving public assistance had no significant excess risk for all-cause death at 1 year after discharge or a heart failure hospitalization within 180 days after discharge, while they did have a significant excess risk for heart failure hospitalizations beyond 180 days after discharge. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02334891 (NCT02334891) and https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000017241 (UMIN000015238)

    Ischemic Stroke in Acute Decompensated Heart Failure: From the KCHF Registry

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    [Background] Heart failure (HF) is a known risk factor for ischemic stroke, but data regarding ischemic stroke during hospitalization for acute decompensated HF (ADHF) are limited. [Methods and Results] We analyzed the data from a multicenter registry (Kyoto Congestive Heart Failure [KCHF] Registry) that enrolled 4056 consecutive patients with ADHF in Japan (mean age, 78 years; men, 2238 patients [55%]; acute coronary syndrome [ACS], 239 patients [5.9%]). We investigated the incidence and predictors of ischemic stroke during hospitalization for ADHF. During the hospitalization, 63 patients (1.6%) developed ischemic stroke. The median interval from admission to the onset of ischemic stroke was 7 [interquartile range: 2–14] days, and the most common underlying cause was cardioembolism (64%). Men (OR, 1.87; 95%CI, 1.11–3.24), ACS (OR, 2.31; 95%CI, 1.01–4.93), absence of prior HF hospitalization (OR, 2.21; 95%CI, 1.24–4.21), and high B‐type natriuretic peptide (BNP)/N‐terminal proBNP (NT‐proBNP) levels (above the median) at admission (OR, 3.15; 95%CI, 1.84–5.60) were independently associated with ischemic stroke. In patients without ACS, the independent risk factors for ischemic stroke were fully consistent with those in the main analysis. Higher quartiles of BNP/NT‐proBNP levels were significantly associated with higher incidence of ischemic stroke (P for trend, <0.001). Patients with ischemic stroke showed higher in‐hospital mortality, longer length of hospital stay, and poorer functional status at discharge. [Conclusions] During hospitalization for ADHF, 1.6% of the patients developed ischemic stroke. Men, ACS, absence of prior HF hospitalization, and high BNP/NT‐proBNP levels at admission were independently associated with ischemic stroke

    Association of an increase in serum albumin levels with positive 1-year outcomes in acute decompensated heart failure: A cohort study

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    Background: Despite the prognostic importance of hypoalbuminemia, the prognostic implication of a change in albumin levels has not been fully investigated during hospitalization in patients with acute decompensated heart failure (ADHF). Methods: Using the data from the Kyoto Congestive Heart Failure registry on 3160 patients who were discharged alive for acute heart failure hospitalization and in whom the change in albumin levels was calculated at discharge, we evaluated the association with an increase in serum albumin levels from admission to discharge and clinical outcomes by a multivariable Cox hazard model. The primary outcome measure was a composite of all-cause death or hospitalization for heart failure. Findings: Patients with increased albumin levels (N = 1083, 34.3%) were younger and less often had smaller body mass index and renal dysfunction than those with no increase in albumin levels (N = 2077, 65.7%). Median follow-up was 475 days with a 96% 1-year follow-up rate. Relative to the group with no increase in albumin levels, the lower risk of the increased albumin group remained significant for the primary outcome measure (hazard ratio: 0.78, 95% confidence interval: 0.69–0.90: P = 0.0004) after adjusting for confounders including baseline albumin levels. When stratified by the quartiles of baseline albumin levels, the favorable effect of increased albumin was more pronounced in the lower quartiles of albumin levels, but without a significant interaction effect (interaction P = 0.49). Conclusions: Independent of baseline albumin levels, an increase in albumin during index hospitalization was associated with a lower 1-year risk for a composite of all-cause death and hospitalization in patients with acute heart failure
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