Nuchal Ligament Reconstruction Surgery for Dropped Head Syndrome: A Case Report.

Case: An 86-year-old woman suffered from dropped head syndrome (DHS). As she was not willing to undergo fusion surgery, we proposed a novel nuchal ligament reconstruction surgery, which is not a direct correction of the malalignment but rather a recovery of the function of extensor muscles under local anesthesia. Twelve months after surgery, the patient remains satisfied and is able to maintain a horizontal gaze.

Optimal treatment conditions for low-intensity pulsed ultrasound therapy for Alzheimer's disease: applications from mice to humans.

Purpose: We previously developed a novel therapy with low-intensity pulsed ultrasound (LIPUS) that ameliorates cognitive decline through upregulation of endothelial nitric oxide synthase (eNOS) in mouse models of Alzheimer's disease (AD). In a randomized, double-blind, placebo-controlled pilot trial, we demonstrated that whole-brain LIPUS therapy is safe and tends to suppress the cognitive decline in early AD patients. We herein report the findings of our basic experiments that we performed for the pilot trial in order to apply whole-brain LIPUS therapy to humans, as well.

Influence of Power-Weighted Center of Echo Signal Within Window Function on Local Strain Rate Distribution in Left Ventricular Wall.

Objective: The deviation of the power-weighted center of the echo signal from the geometric center within the velocity estimation window for calculating strain rate (SR) causes an estimation error. This study aimed to confirm whether an erroneous multilayer pattern in the SR distribution of the left ventricular wall could be corrected by considering the power-weighted center of the echo signal.

Methods: The SR distributions were measured locally in the transmural direction around the pre-ejection and early diastolic phases in healthy volunteers.

A novel ultrasonic method for measuring minute sinusoidal displacement by network analyzer.

We developed a method for generating continuous sinusoidal displacements of an object to estimate viscoelastic parameters. However, the amplitude of the displacement caused by the ultrasonic excitation force under safe guidelines was small (a few micrometers), and it was difficult to stably measure the displacement. Therefore, to stably measure the amplitude of sinusoidal displacement as small as the order of micrometers, we proposed a novel method using a network analyzer.

Optimizing irradiation conditions for low-intensity pulsed ultrasound to upregulate endothelial nitric oxide synthase.

Purpose: Here we aimed to develop a minimally invasive treatment for ischemic heart disease and demonstrate that low-intensity pulsed ultrasound (LIPUS) therapy improves myocardial ischemia by promoting myocardial angiogenesis in a porcine model of chronic myocardial ischemia. Studies to date determined the optimal treatment conditions within the range of settings available with existing ultrasound equipment and did not investigate a wider range of conditions.

Methods: We investigated a broad range of five parameters associated with ultrasound irradiation conditions that promote expression of endothelial nitric oxide synthase (eNOS), a key molecule that promotes angiogenesis in human coronary artery endothelial cells (HCAEC).

Estimation error in speed of sound caused by rotation of measured cross-section from short-axis plane of blood vessels: a preliminary study.

Purpose: Estimating the speed of sound (SoS) in ultrasound propagation media is important for improving the quality of B-mode images and for quantitative tissue characterization. We have been studying a method for estimating the SoS by measuring the reception time distribution of waves scattered from a scatterer at the elements in a probe. Previously, the measurement cross section was assumed to be perpendicular to the long axis of the blood vessel.

A randomized, double-blind, placebo-controlled pilot trial of low-intensity pulsed ultrasound therapy for refractory angina pectoris.

Background: Despite the advances in the treatment of cardiovascular diseases, effective treatment remains to be established to improve the quality of life and prognosis of patients with chronic coronary syndromes. This study was aimed to evaluate the effectiveness and safety of the low-intensity pulsed ultrasound (LIPUS) therapy, which we have developed as a novel non-invasive angiogenic therapy through upregulation of endothelial nitric oxide synthase (eNOS).

Methods And Findings: We conducted a randomized, double-blind, placebo-controlled (RCT) pilot trial of the LIPUS therapy for patients with refractory angina pectoris.

Beneficial Effects of Low-Intensity Pulsed Ultrasound Therapy on Right Ventricular Dysfunction in Animal Models.

Right ventricular failure (RVF) is a leading cause of death in patients with pulmonary hypertension; however, effective treatment remains to be developed. We have developed low-intensity pulsed ultrasound therapy for cardiovascular diseases. In this study, we demonstrated that the expression of endothelial nitric oxide synthase (eNOS) in RVF patients was downregulated and that eNOS expression and its downstream pathway were ameliorated through eNOS activation in 2 animal models of RVF.

Speed-of-sound estimation in ultrasound propagation medium by considering size of target scatterer.

Purpose: Accurate speed-of-sound (SoS) estimation in an ultrasound propagation medium improves imaging quality and contributes to better diagnosis of diseases. In conventional time-delay-based SoS estimation approaches studied by several groups, a received wave is assumed to be scattered from an ideal point scatterer. In these approaches, the SoS is overestimated when the target scatterer has a non-negligible size.

Lateral M-Mode: Ultrasound Visualization of Displacement Along Longitudinal Direction at Intima-Media Complex.

Quantification of the dynamics of the carotid artery wall is useful in evaluating arteriosclerosis and atherosclerosis. As the carotid artery wall moves not only in the radial direction but also in the longitudinal direction, longitudinal movement should be considered in the analysis of the dynamic properties of the carotid artery wall. In this study, we propose a "lateral M-mode" method for visualizing the longitudinal movement of the intima-media complex (IMC).

Evaluation of two semi-supervised learning methods and their combination for automatic classification of bone marrow cells.

Differential bone marrow (BM) cell counting is an important test for the diagnosis of various hematological diseases. However, it is difficult to accurately classify BM cells due to non-uniformity and the lack of reproducibility of differential counting. Therefore, automatic classification systems have been developed in which deep learning is used.

Application of low-complexity generalized coherence factor to in vivo data.

Purpose: Beamforming using the generalized coherence factor (GCF) reduces sidelobe artifacts and provides an excellent contrast-to-noise ratio. We previously proposed GCF, a method to calculate GCF without generating analytic signals, and GCF, a method to calculate GCF by binarizing the received signals. In this study, we applied these methods to in vivo data and showed the effect of the computational complexity reduction on contrast performance.

Evaluation of local changes in radio-frequency signal waveform and brightness caused by vessel dilatation for ascertaining reliability of elasticity estimation inside heterogeneous plaque: a preliminary study.

Purpose: To diagnose plaque characteristics, we previously developed an ultrasonic method to estimate the local elastic modulus from the ratio of the pulse pressure to the strain of the arterial wall due to dilatation in systole by transcutaneously measuring the minute thinning in thickness during one cardiac cycle. For plaques, however, some target regions became thicker as the vessel dilates, resulting in false elasticity. Therefore, a method to identify a reliable target for the elastic modulus estimation is indispensable.

Appropriate Window Function and Window Length in Multifrequency Velocity Estimator for Rapid Motion and Locality of Layered Myocardium.

The heart wall has a multilayered structure and moves rapidly during ejection and rapid filling periods. Local strain rate (SR) measurements of each myocardial layer can contribute to accurate and sensitive evaluations of myocardial function. However, ultrasound-based velocity estimators using a single-frequency phase difference cannot realize these measurements owing to insufficient maximum detectable velocity, which is limited by a quadrature frequency.

Strain Rate Distribution in Layered Myocardium Measured Using Local Velocity Estimator with Multifrequency Phase Differences.

Measurement of the myocardial strain rate (SR), with high spatial resolution, is useful in evaluation of the transmurality of myocardial infarction. As the SR distribution is calculated using velocities observed at multiple positions in the heart wall, it is necessary to estimate the local velocity to measure SR distribution. In the present study, our previously proposed local velocity estimator, with multifrequency phase differences, was used to measure SR distribution in the heart wall.

Low-complexity generalized coherence factor estimated from binarized signals in ultrasound beamforming.

Purpose: In coherence-based beamforming (CBB) using a generalized coherence factor (GCF), unnecessary signals caused by sidelobes are reduced, and an excellent contrast-to-noise ratio (CNR) is achieved in ultrasound imaging. However, the GCF computation is complex compared to the standard delay-and-sum (DAS) beamforming. In the present study, we propose a method that significantly reduces the number of GCF computations.

Low-intensity pulsed ultrasound therapy promotes recovery from stroke by enhancing angio-neurogenesis in mice in vivo.

Since the treatment window of thrombolytic therapy for stroke is limited, new therapy remains to be developed. We have recently developed low-intensity pulsed ultrasound (LIPUS) therapy to improve cognitive dysfunction in mouse models of vascular dementia and Alzheimer's disease. Here, we further aimed to examine whether our LIPUS therapy improves neurological recovery from ischemic stroke, and if so, to elucidate the mechanisms involved.

Multifrequency Phased Tracking Method for Estimating Velocity in Heart Wall.

Local high-accuracy velocity estimation is important for the ultrasound-based evaluation of regional myocardial function. The ultrasound phase difference at the center frequency of the transmitted signal has been conventionally used for velocity estimation. In the conventional method, spatial averaging is necessary owing to the frequency-dependent attenuation and interference of backscattered waves.

Evaluation method of the degree of red blood cell aggregation considering ultrasonic propagation attenuation by analyzing ultrasonic backscattering properties.

Purpose: Red blood cell (RBC) aggregation is one of the main factors that determines blood viscosity and an important indicator for evaluating blood properties. As a noninvasive and quantitative method for diagnosing blood properties, our research group estimated the size of RBC aggregates by fitting the scattered power spectrum from the blood vessel lumen with the theoretical scattering characteristics to evaluate the degree of RBC aggregation. However, it was assumed that the propagation attenuation of ultrasound in the vascular lumen was the same regardless of whether RBCs were aggregated or not, which caused systematic errors in the estimated size.

Ultrasound measurement of fetal arterial pulse pressure using phased-tracking methods: A phantom study and clinical experience with antenatal corticosteroid therapy.

Aim: This study aimed to compare the accuracy of fetal pulse pressure estimated with a vascular simulator with that obtained by a manometer (reference) and evaluate the pulse pressure in normal human fetuses and fetuses whose mothers received corticosteroids.

Methods: Fetal pulse pressure was estimated as the product of blood flow velocity and pulse wave velocity, based on the water hammer equation. Ultrasonic raw radiofrequency signals for blood flow velocity were captured from the fetal descending aortas at the diaphragm level, and pulse wave velocity was simultaneously measured from different directions using the phased-tracking method.

Feasibility of Non-invasive Pulse Pressure Measurement Using the Phased-Tracking Method.

Phased tracking (PT) is a high-precision ultrasonic technology that enables measurements of pulse pressure (PP). The aim of this study was to verify the accuracy of estimated PP using PT. Estimated PPs were compared with measured PPs in three sheep fetuses that were connected to an artificial placenta system.

Low-intensity pulsed ultrasound ameliorates cardiac diastolic dysfunction in mice: a possible novel therapy for heart failure with preserved left ventricular ejection fraction.

Aims: Heart failure with preserved left ventricular ejection fraction (HFpEF) is a serious health problem worldwide, as no effective therapy is yet available. We have previously demonstrated that our low-intensity pulsed ultrasound (LIPUS) therapy is effective and safe for angina and dementia. In this study, we aimed to examine whether the LIPUS therapy also ameliorates cardiac diastolic dysfunction in mice.

Artificial control of the multistep oxidation reactions catalyzed by the cytochrome P450 enzyme RosC.

The cytochrome P450 monooxygenase RosC catalyzes the three-step oxidation reactions, which leads to the formation of a hydroxy, formyl, and carboxy group at C-20 during rosamicin biosynthesis in Micromonospora rosaria IFO13697. To determine if amino acid substitutions in RosC could allow for the control of the multistep oxidation reactions, we screened RosC random mutants. The RosC mutant RM30, with five amino acid substitutions (P107S, L176Q, S254N, V277A, and I319N), catalyzed only the first step of the oxidation reaction.