Publications by authors named "Masayuki Nakano"

Background: Tibetan highlanders have adapted to hypoxic environments through genetic mechanisms that avoid hemoglobin concentration increases and prevent polycythemia. Recently, sex differences in hemoglobin dynamics with age have been reported among Tibetan highlanders living in Tsarang. Additionally, concerns have been raised that dietary changes associated with modernization may increase the risk of polycythemia and lifestyle-related diseases among Tibetan highlanders.

View Article and Find Full Text PDF

The Heisenberg uncertainty principle dictates that the position and momentum of an object cannot be simultaneously measured with arbitrary precision, giving rise to an apparent limitation known as the standard quantum limit (SQL). Gravitational-wave detectors use photons to continuously measure the positions of freely falling mirrors and so are affected by the SQL. We investigated the performance of the Laser Interferometer Gravitational-Wave Observatory (LIGO) after the experimental realization of frequency-dependent squeezing designed to surpass the SQL.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to assess the effectiveness and safety of MR-guided focused ultrasound (MRgFUS) treatment for patients with essential tremor, particularly focusing on those with a low skull density ratio (SDR).
  • Real-world data from 101 patients treated between July 2019 and March 2022 were analyzed, categorizing patients into four quartiles based on their mean SDR and evaluating treatment outcomes, parameters, and adverse events.
  • Results showed that MRgFUS significantly improved tremor severity across all SDR groups, but individuals with very low SDR experienced lower temperature and coagulation volume during treatment, along with more frequent adverse events, which mostly resolved by the 3-month follow-up.
View Article and Find Full Text PDF
Article Synopsis
  • The Clinical Rating Scale for Tremor (CRST) is widely used but has limitations like ceiling effects and variability in test results when assessing essential tremor (ET).
  • This study tested videographic motion analysis as a new way to evaluate ET by recording patients performing tasks and analyzing the videos with software.
  • The findings showed that video analysis provided reliable measurements that correlated well with traditional CRST scores and was effective in tracking improvements after focused ultrasound treatment for tremor.
View Article and Find Full Text PDF

Among hepatocellular carcinoma (HCC), early HCC such as well-differentiated hepatocellular carcinoma is more difficult to distinguish from non-cancer than other cancers. In particular, very well-differentiated hepatocellular carcinoma is even more difficult to distinguish, and it is difficult for pathologists to distinguish between cancer and non-cancer from a single nucleus image. If a function to distinguish cancer with a single cell nucleus image is realized, it may be possible to find new features related to nuclei that are useful for differentiating early HCC.

View Article and Find Full Text PDF
Article Synopsis
  • Transcranial magnetic resonance-guided focused ultrasound surgery (TcMRgFUS) enables real-time assessment of treatment effectiveness through intraoperative MRI, but current imaging quality with a 3.0T MRI system needs improvement for accurate lesion detection.
  • A study was conducted comparing automatically adjusted transmitter gain (auto TG) and manually adjusted transmitter gain (manual TG) on image quality, measuring factors like flip angle, uniformity, and signal-to-noise ratio.
  • Results showed that manual TG provided better image uniformity and higher signal-to-noise ratios, leading to clearer lesion visualization in clinical cases compared to auto TG, indicating its superiority for TcMRgFUS imaging.
View Article and Find Full Text PDF
Article Synopsis
  • A patient with tremor-dominant Parkinson's disease experienced mild cavitation effects during a procedure called magnetic resonance-guided focused ultrasound thalamotomy, which caused temporary speech difficulties and numbness.
  • Despite these issues, the patient's tremor and rigidity improved, and MRI scans showed significant changes in the thalamus after the procedure.
  • Although cavitation can help alleviate symptoms, it requires close monitoring to minimize the risk of lasting adverse effects due to its unpredictable nature.
View Article and Find Full Text PDF

Imaging methods have the overwhelming advantage of being non-invasive in the diagnosis of hepatic lesions and, thanks to technical developments in the field of ultrasound (US), radiation exposure can also be avoided in many clinical situations. In particular, contrast-enhanced US (CEUS) outperforms other radiological methods in regard to real-time images, repeatability, and prompt reporting and demonstrates relatively few contraindications and adverse reactions. In this study, we reported in detail a rare benign tumor: hepatic sclerosed hemangioma (HSH).

View Article and Find Full Text PDF

Background: In Tsarang (at 3560 m), which is located in Mustang, 62.7% of the residents answered that they had a subjective medical history of arthritis, and 41.1% of the residents answered that their families had a subjective medical history of arthritis on a survey conducted in 2017.

View Article and Find Full Text PDF

Pulmonary hypertension (PH) is a severe and progressive disease that causes elevated right ventricular systolic pressure, right ventricular hypertrophy and ultimately right heart failure. However, the underlying pathophysiologic mechanisms are poorly understood. We previously showed that 3,4-l-dihydroxylphenyalanine (DOPA) sensitizes vasomotor response to sympathetic tone via coupling between the adrenergic receptor alpha1 (ADRA1) and a G protein-coupled receptor 143 (GPR143), a DOPA receptor.

View Article and Find Full Text PDF

Objective: Sufficient thermal increase capable of generating thermocoagulation is indispensable for an effective clinical outcome in patients undergoing magnetic resonance-guided focused ultrasound (MRgFUS). The skull density ratio (SDR) is one of the most dominant predictors of thermal increase prior to treatment. However, users currently rely only on the average SDR value (SDRmean) as a screening criterion, although some patients with low SDRmean values can achieve sufficient thermal increase.

View Article and Find Full Text PDF

A 67-year-old male with type 2 diabetes (T2DM) was diagnosed with postoperative intrahepatic recurrence for hepatocellular carcinoma (HCC). Nine sessions of transarterial chemoembolization (TACE) proved ineffective, and the patient was diagnosed as having TACE-refractory disease and received seven cycles of atezolizumab-bevacizumab combination therapy. After that, the patient developed hyperglycemia with the HbA1c elevation and the marked fasting serum C-peptide reduction and was diagnosed with developed immune-mediated diabetes (IMD) (T2DM exacerbation with insulin-dependent diabetes development).

View Article and Find Full Text PDF

Elevated angiotensin-converting enzyme 2 (ACE2) expression in organs that are potential targets of severe acute respiratory syndrome coronavirus 2 may increase the risk of coronavirus disease 2019 (COVID-19) infection. Previous reports show that ACE2 alter its tissue-specific expression patterns under various pathological conditions, including renal diseases. Here, we examined changes in pulmonary ACE2 expression in two mouse chronic kidney disease (CKD) models: adenine-induced (adenine mice) and aristolochic acid-induced (AA mice).

View Article and Find Full Text PDF

Background: This study aimed to compare the value of Sonazoid contrast-enhanced ultrasound (SCEUS) with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid magnetic resonance imaging (EOB-MRI) for histological grading diagnosis, especially for early hepatocellular carcinoma (eHCC).

Methods: A total of 163 histopathologically confirmed HCC lesions were retrospectively collected, including 71 eHCCs (27 hypervascular, 44 non-hypervascular) and 92 advanced HCCs (adHCC) (73 hypervascular, 19 non-hypervascular). We performed SCEUS to evaluate the lesions' vascularity during the portal phase (PP) and the echogenicity during the post-vascular phase (PVP).

View Article and Find Full Text PDF

Radiotherapy is one of the available curative therapies for hepatocellular carcinoma (HCC). We investigate the use of contrast-enhanced ultrasound using Sonazoid (SCEUS) in evaluating the efficacy of radiotherapy for HCC. We enrolled 59 patients with 59 HCCs in this retrospective study.

View Article and Find Full Text PDF
Article Synopsis
  • The study focuses on improving temperature estimates in transcranial magnetic resonance imaging-guided focused ultrasound (TcMRgFUS) by standardizing the skull density ratio (SDR), which varies based on the reconstruction filter used in imaging.
  • Researchers developed a method to correct the modulation transfer function (MTF) of different filters to stabilize the SDR and enhance patient screening for treatment.
  • Results showed that after applying the correction method, the variability in SDR was significantly reduced, though no correlation was found between the corrected SDR and the maximum temperature achieved during TcMRgFUS treatment in the patient cases analyzed.
View Article and Find Full Text PDF

Background: Tibetan highlanders have adapted to hypoxic environments through the development of unique mechanisms that suppress an increase in hemoglobin (Hb) concentration even in high-altitude areas. Hb concentrations generally decrease with increasing age. However, in the highlands, chronic altitude sickness is known to occur in the elderly population.

View Article and Find Full Text PDF

Purpose: To estimate the role of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MRI (EOB-MRI) in predicting hypervascularization outcome of non-hypervascular hypointense hepatic lesions in high-risk patients for hepatocellular carcinoma (HCC).

Methods: Under the premise of non-hyperenhance in arterial phase (AP) and hypointensity in hepatobiliary phase (HBP) of EOB-MRI, 29 fresh lesions from 22 patients with chronic viral hepatitis (median (range) age: 69(57-82) years) were prospectively enrolled. During continuously followed-up by EOB-MRI, lesional vascularity in AP, the signal intensity (SI) ratios of lesions-to-parenchyma in HBP images (post-contrast ratio) and adjusted enhancement with reference of unenhanced images (EOB enhancement ratio) were examined.

View Article and Find Full Text PDF

Aim: Hepatocellular adenoma (HCA) has a lower prevalence in Japan than in Western countries and HCA subtypes have been reported for only a few Japanese patients. We analyzed HCA subtype data 38 patients from 23 hospitals in Japan in order to examine character and difference between Western countries.

Methods: To confirm HCA and to analyze subtypes, we performed immunohistochemical examinations.

View Article and Find Full Text PDF

To clarify the early hemodynamics of hepatocellular carcinoma (HCC), we defined the early portal phase of contrast-enhanced ultrasound (CEUS) and examined the reliability of this modality for determining HCC differentiation. Starting in 2007, we performed Sonazoid CEUS in 146 pathologically confirmed hepatic nodules; 118 HCC (8 poorly [Pd], 73 moderately [Md] and 37 well-differentiated [Wd]) and 28 benign nodules. We focused on the pure arterial and early portal phases up to 45 seconds after Sonazoid injection, and then the subsequent phase up to 30 minutes.

View Article and Find Full Text PDF
Article Synopsis
  • A study was conducted seven years after the Great East Japan Earthquake to explore telomeres as an indicator of stress in children based on their exposure to the disaster.
  • The research focused on children aged 5-9 living in Rikuzentakata, Japan, and involved measuring their relative telomere length (rTL) using saliva samples.
  • Results showed that children conceived after the disaster had significantly shorter rTL compared to those who were in utero during the event, suggesting telomere length may be a useful biomarker for assessing trauma related to disasters in future research.
View Article and Find Full Text PDF

A recursive additive complement network (RacNet) is introduced to segment cell membranes in histological images as closed lines. Segmenting cell membranes as closed lines is necessary to calculate cell areas and to estimate N/C ratio, which is useful to diagnose early hepatocellular carcinoma. The RacNet is composed of a complement network and an element-wise maximization (EWM) process and is recursively applied to the network output.

View Article and Find Full Text PDF

Background & Aims: To explore the ability of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid magnetic resonance imaging (EOB-MRI)/ultrasound (US) fusion imaging (FI) to improve the prognosis of radiofrequency ablation (RFA) by ablating the characteristic findings of hepatocellular carcinoma (HCC) in hepatobiliary phase (HBP) imaging.

Methods: We retrospectively recruited 115 solitary HCC lesions with size of (15.9 ± 4.

View Article and Find Full Text PDF

A 70-year-old female was found to have multiple hepatic cysts at her annual checkup. In the posterior segment of the right lobe of the liver, an 81 × 67 mm circular cystic lesion was detected by contrast-enhanced computed tomography (CT). Magnetic resonance imaging (MRI) of the cyst revealed a solid component.

View Article and Find Full Text PDF