Publications by authors named "Megumi Matsuda"

Objectives: This study evaluated the feasibility of a model-based iterative reconstruction technique (MBIR) tuned for the myocardium on myocardial computed tomography late enhancement (CT-LE).

Methods: Twenty-eight patients who underwent myocardial CT-LE and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) within 1 year were retrospectively enrolled. Myocardial CT-LE was performed using a 320-row CT with low tube voltage (80 kVp).

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Stretchable conjugated polymers with conjugation break spacers (CBSs) synthesized via random terpolymerization have gained considerable attention because of their efficacy in modulating mobility and stretchability. This study incorporates a series of dianhydrohexitol diastereomers of isosorbide (ISB) and isomannide (IMN) units into the diketopyrrolopyrrole-based backbone as CBSs. It is found that the distorted CBS (IMN) improves the mobility-stretchability properties of the polymer with a highly coplanar backbone, whereas the extended CBS (ISB) enhances those of the polymer with a noncoplanar backbone.

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Coronary artery disease (CAD) is a common condition caused by the accumulation of atherosclerotic plaques. It can be classified into stable CAD or acute coronary syndrome. Coronary computed tomography angiography (CCTA) has a high negative predictive value and is used as the first examination for diagnosing stable CAD, particularly in patients at intermediate-to-high risk.

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The development of intrinsically stretchable -type semiconducting polymers has garnered much interest in recent years. In this study, three biobased dianhydrohexitol epimers of isosorbide (), isomannide (), and isoidide (), derived from cellulose, were incorporated into the backbone of a naphthalenediimide (NDI)-based -type semiconducting polymer as conjugation break spacers (CBSs). Accordingly, three polymers were synthesized through the Migita-Kosugi-Stille coupling polymerization with NDI, bithiophene, and CBSs, and the mobility-stretchability properties of these polymers were investigated and compared with those of their analogues with conventional alkyl-based CBSs.

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Vertebral artery dissection can occur in intracranial or extracranial vertebral arteries. However, the simultaneous dissection of both intracranial and extracranial vertebral arteries is extremely rare. We describe a 45-year-old man with simultaneous intracranial and extracranial vertebral artery dissections in separate sites.

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Excessive inflammation has been implicated in autism spectrum disorder (ASD), but the underlying mechanisms have not been fully studied. SHANK3 is a synaptic scaffolding protein and mutations of are involved in ASD. Shank3 expression in dorsal root ganglion sensory neurons also regulates heat pain and touch.

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Objective: This study aimed to compare the image quality in the hepatobiliary phase images of gadoxetic acid-enhanced liver magnetic resonance imaging using parallel imaging (PI) and compressed sensing (CS) reconstruction, using variable CS factors with the standard method using the PI technique.

Methods: In this study, 64 patients who underwent gadoxetic acid-enhanced liver magnetic resonance imaging at 3.0 T were enrolled.

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Vertebral artery stump syndrome is rare, but one of the most important causes of posterior circulation stroke. To our knowledge, no optimal treatment for vertebral artery stump syndrome has been established, and there are no reports of long-term follow-up. We describe a 69-year-old man with vertebral artery stump syndrome who attended our hospital because of vertigo.

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A non-traumatic abdominal wall hematoma is rare, and occurs occasionally due to coughing, physical activity, or antithrombotic/anticoagulant therapy. The condition is usually unilateral; however, rare bilateral cases have been reported. Here, we report a rare case of a non-traumatic bilateral rectus sheath hematoma.

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Article Synopsis
  • A 57-year-old woman experienced severe neurological symptoms due to a stroke caused by a free-floating thrombus (FFT) in the internal carotid artery (ICA).
  • Despite initial medical treatment for the embolic infarction, the FFT detached and led to occlusion of the ICA.
  • The blockage was successfully treated with mechanical thrombectomy, highlighting the risks associated with FFTs and the importance of timely intervention strategies.
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Background: An extremely tortuous superior cerebellar artery is a rare anomaly. We report a case of an extremely tortuous superior cerebellar artery mimicking an aneurysm.

Case Description: A 77-year-old woman was initially diagnosed with unruptured cerebral aneurysm at the right basilar artery-superior cerebellar artery junction by magnetic resonance angiography.

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Dynamic regulation of G-protein-coupled receptor (GPCR) kinase 2 (GRK2) expression restores cellular function by protecting from overstimulation via GPCR and non-GPCR signaling. In the primary afferent neurons, GRK2 negatively regulates nociceptive tone. The present study tested the hypothesis that induction of GRK2 in the primary afferent neurons contributes to the resolution of acute pain after tissue injury.

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Purpose: This study aimed to compare the characteristics of triple-negative breast cancer (TNBC) with non-TNBC on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and synthetic MRI.

Method: This retrospective study included 79 patients with histopathologically proven breast cancer (TNBC: 16, non-TNBC: 63) who underwent synthetic MRI. Using synthetic MR images, we obtained T1 and T2 relaxation times in breast lesions before (Pre-T1, Pre-T2, Pre-PD) and after (Gd-T1, Gd-T2, Gd-PD) contrast agent injection.

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Objective: In parent artery occlusion (PAO) for ruptured vertebral artery dissecting aneurysms (RVADA), target embolization using coils in a short segment to occlude only the vasodilated area containing the rupture point is selected as a first-choice procedure at our institute. We focused on RVADA involving the posterior inferior cerebellar artery (PICA) and evaluated the treatment results.

Methods: This study consisted of eight cases with RVADA involving the PICA which were treated between October 2007 and January 2020.

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The immune checkpoint inhibitor programmed cell death protein 1 (PD-1) plays a critical role in immune regulation. Recent studies have demonstrated functional PD-1 expression in peripheral sensory neurons, which contributes to neuronal excitability, pain, and opioid analgesia. Here we report neuronal expression and function of PD-1 in the central nervous system (CNS), including the spinal cord, thalamus, and cerebral cortex.

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Oxytocin (OT), a neuropeptide involved in the regulation of complex social and sexual behavior in mammals, has been proposed as a treatment for a number of psychiatric disorders including pain. It has been well documented that central administration of OT elicits strong scratching and grooming behaviors in rodents. However, these behaviors were only described as symptoms, few studies have investigated their underlying neural mechanisms.

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Background: The addition of synthetic MRI might improve the diagnostic performance of dynamic contrast-enhanced MRI (DCE-MRI) in patients with breast cancer.

Purpose: To evaluate the diagnostic value of a combination of DCE-MRI and quantitative evaluation using synthetic MRI for differentiation between benign and malignant breast masses.

Study Type: Retrospective, observational.

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The present study was performed to determine neuronal loci and individual molecular mechanisms responsible for remifentanil-induced hyperalgesia. The effect of methylnaltrexone (MNX) on remifentanil-induced behavioral hyperalgesia was assessed to distinguish contributions of the peripheral and/or central nervous system to remifentanil-induced hyperalgesia. Phosphorylation of p38 mitogen-activated protein kinase (p38MAPK) in the dorsal root ganglion (DRG) neurons after remifentanil infusion, and the effect of a p38MAPK inhibitor on remifentanil-induced hyperalgesia were analyzed to investigate involvement of p38MAPK in the peripheral mechanisms of remifentanil-induced hyperalgesia.

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Emerging immunotherapies with monoclonal antibodies against programmed cell death protein-1 (PD-1) have shown success in treating cancers. However, PD-1 signaling in neurons is largely unknown. We recently reported that dorsal root ganglion (DRG) primary sensory neurons express PD-1 and activation of PD-1 inhibits neuronal excitability and pain.

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The proinflammatory cytokine interleukin-17 (IL-17) is implicated in pain regulation. However, the synaptic mechanisms by which IL-17 regulates pain transmission are unknown. Here, we report that glia-produced IL-17 suppresses inhibitory synaptic transmission in the spinal cord pain circuit and drives chemotherapy-induced neuropathic pain.

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Purpose: To evaluate the image quality and lesion visibility of virtual monoenergetic images (VMIs) reconstructed using a new monoenergetic reconstruction algorithm (nMERA) for evaluation of breast cancer.

Materials And Methods: Forty-two patients with 46 breast cancers who underwent 4-phasic breast contrast-enhanced computed tomography (CT) using dual-energy CT (DECT) were enrolled. We selected the peak enhancement phase of the lesion in each patient.

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p53 and parkin are involved in mitochondrial quality control. The present study aimed to characterize the functional significance of parkin/p53 in the development of mitochondrial dysfunction and the pathophysiology of neuropathic pain in type I diabetes. Type I diabetes was induced in mice (N = 170) using streptozotocin (STZ).

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Chemotherapy-induced peripheral neuropathy (CIPN) remains a pressing clinical problem; however, our understanding of sexual dimorphism in CIPN remains unclear. Emerging studies indicate a sex-dimorphic role of Toll-like receptor 4 (TLR4) in driving neuropathic pain. In this study, we examined the role of TLR9 in CIPN induced by paclitaxel in WT and mutant mice of both sexes.

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Inflammatory pain hypersensitivity is associated with activation of primary afferent neurons. This study investigated the existence of the inflammasome in dorsal root ganglion (DRG) and the functional significance in the development of inflammatory pain hypersensitivity. Tissue inflammation was induced in male C57BL/6 mice with complete Freund's adjuvant (CFA) or ceramide injection into the hind paw.

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Mechanical allodynia is a cardinal feature of pathological pain. Recent work has demonstrated the necessity of Aβ-low-threshold mechanoreceptors (Aβ-LTMRs) for mechanical allodynia-like behaviors in mice, but it remains unclear whether these neurons are sufficient to produce pain under pathological conditions. We generated a transgenic mouse in which channelrhodopsin-2 (ChR2) is conditionally expressed in vesicular glutamate transporter 1 (Vglut1) sensory neurons (Vglut1-ChR2), which is a heterogeneous population of large-sized sensory neurons with features consistent with Aβ-LTMRs.

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