Publications by authors named "Yuki Miyata"

In vertebrate development, ectoderm is specified into neural plate (NP), neural plate border (NPB), and epidermis. Although such patterning is thought to be achieved by molecular concentration gradients, it has been revealed, mainly by analysis, that mechanical force can regulate cell specification. During patterning, cells deform and migrate, and this applies force to surrounding tissues, shaping the embryo.

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Objectives: Computer-aided characterization (CADx) may be used to implement optical biopsy strategies into colonoscopy practice; however, its impact on endoscopic diagnosis remains unknown. We aimed to evaluate the additional diagnostic value of CADx when used by endoscopists for assessing colorectal polyps.

Methods: This was a single-center, multicase, multireader, image-reading study using randomly extracted images of pathologically confirmed polyps resected between July 2021 and January 2022.

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BACKGROUND: Artificial intelligence using computer-aided diagnosis (CADx) in real time with images acquired during colonoscopy may help colonoscopists distinguish between neoplastic polyps requiring removal and nonneoplastic polyps not requiring removal. In this study, we tested whether CADx analyzed images helped in this decision-making process. METHODS: We performed a multicenter clinical study comparing a novel CADx-system that uses real-time ultra-magnifying polyp visualization during colonoscopy with standard visual inspection of small (≤5 mm in diameter) polyps in the sigmoid colon and the rectum for optical diagnosis of neoplastic histology.

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The echo state property, which is related to the dynamics of a neural network excited by input driving signals, is one of the well-known fundamental properties of recurrent neural networks. During the echo state, the neural network reveals an internal memory function that enables it to remember past inputs. Due to the echo state property, the neural network will asymptotically update its condition from the initial condition and is expected to exhibit temporally nonlinear input/output.

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With the prevalence of endoscopic submucosal dissection and endoscopic full thickness resection, which enable complete resection of T1 colorectal cancer with a negative margin, the treatment strategy following endoscopic resection has become more important. The necessity of secondary surgical resection is determined on the basis of the risk of lymph node metastasis according to the histopathological findings of resected specimens because ~10% of T1 colorectal cancer cases have lymph node metastasis. The current Japanese treatment guidelines state four risk factors for lymph node metastasis: lymphovascular invasion, histological differentiation, depth of submucosal invasion, and tumor budding.

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Objectives: Complete endoscopic healing, defined as Mayo endoscopic score (MES) = 0, is an optimal target in the treatment of ulcerative colitis (UC). However, some patients with MES = 0 show clinical relapse within 12 months. Histologic goblet mucin depletion has emerged as a predictor of clinical relapse in patients with MES = 0.

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Aim: Protein and energy malnutrition is a severe problem for patients with liver cirrhosis (LC) and fasting often induces starvation which is a vitally important outcome. Dietary restriction is essential for endoscopic injection sclerotherapy (EIS) in patients with risky esophageal varices, thereby creating the possible exacerbation of nutritional state and inducing liver dysfunction. Whether EIS induces nutritional deficiency in LC patients and the effects of branched-chain amino acid (BCAA)-enriched nutrient are prospectively investigated.

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Aim: The combination therapy of pegylated interferon-α and ribavirin (PEG IFN/RBV) is one of the effective treatments for chronic hepatitis C (CHC) patients. Natural killer (NK)-cell activity was reported to be impaired in patients with hepatitis C virus (HCV). The aim of this study was to examine whether PEG IFN/RBV therapy could restore NK activity in CHC patients.

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Background And Aim: Liver cirrhosis (LC) is accompanied by hepatic arterializations, intrahepatic shunts, and hyperdynamic circulations. These changes shorten the arrival time (AT) of ultrasound contrast agents to the hepatic vein (HV). Whether treatment of gastric fundal varices (GVs) by balloon-occluded transvenous obliteration (B-RTO) improves the AT in LC patients was prospectively investigated.

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Background: Argon plasma coagulation (APC) is very useful as a consolidation treatment for reducing the recurrence of esophageal varices (EVs). However, repeated sedation in endoscopic treatment has the risk of prolonging hepatic encephalopathy and affects the respiratory state of liver cirrhosis (LC) patients, in whom pulmonary arteriovenous shunts are observed. We evaluated prospectively whether transnasal endoscopic APC without sedation is more effective than peroral endoscopic APC with sedation.

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Background: Acoustic radiation force impulse (ARFI) elastography is an ultrasound technique that is capable of measuring tissue stiffness noninvasively. It is difficult to differentiate idiopathic portal hypertension (IPH) from liver cirrhosis (LC) or chronic hepatitis (CH), and liver biopsy is essential. We investigated whether it would be possible to noninvasively diagnose IPH by measuring the stiffness of the liver and spleen by ARFI.

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Objective: To clarify the usefulness of transnasal esophagogastroduodenoscope (N-EGD) with all flexible imaging color enhancement (FICE) patterns (0-9) for the diagnosis of esophageal varices (EV).

Methods: A total of 50 patients with EV were examined during the same period by N-EGD without sedation and by peroral endoscopy (O-EGD) with sedation. The visibility of treatment scars, microvessels, recurrent EV and red color sign (RCS) were measured.

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Aim: To investigate the diagnosis of nonalcoholic steatohepatitis (NASH) using contrast ultrasonography in the NASH rat model.

Methods: The liver in methionine choline-deficient diet (MCDD) rats, a NASH model constructed by feeding an MCDD, was examined by contrast ultrasonography at weeks 2, 4, 8, 12 and 16, with late phase images of contrast ultrasonography (Kupffer imaging) in which contrast enhancement was achieved by incorporation of a contrast agent by Kupffer cells (KCs), and images were compared to those in rats taking a regular chow.

Results: Decrease in contrast enhancement was observed first in MCDD rats at week 2.

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Busulfan, an antineoplastic agent that targets small follicles (primordial and primary follicles), was given orally to female Sprague-Dawley rats (0, 0.1, 0.5, or 1.

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RNA editing in land plant organelles is a process primarily involving the conversion of cytidine to uridine in pre-mRNAs. The process is required for gene expression in plant organelles, because this conversion alters the encoded amino acid residues and improves the sequence identity to homologous proteins. A recent study uncovered that proteins encoded in the nuclear genome are essential for editing site recognition in chloroplasts; the mechanisms by which this recognition occurs remain unclear.

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Delayed parenchymal phase images of the liver more than 5 min after IV injection of ultrasound contrast agents are thought to be related to the phagocytosis of contrast agent microbubbles by macrophages. In this study, we examined whether liver-specific macrophages, Kupffer cells, phagocytosed the microbubbles and whether their elimination affected the delayed parenchymal images of the liver. Phase-contrast microscope observations showed that Kupffer cells phagocytosed various contrast agents in vitro.

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We developed a computed tomography (CT) virtual ultrasound system (CVUS) as an imaging system to support treatment under percutaneous ultrasound (US) guidance. This prototype clinical system, produced in collaboration with Tokyo Medical University, uses display software developed by Toshiba Medical Systems. We examined the utility of this system by scheduling treatment plans preoperatively and simulating puncture and radiofrequency ablation (RFA) for liver cancer.

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Flash-replenishment (FR) utilizes destruction of microbubbles in the scan volume by high-power ultrasound and enables to observe reperfusion at a low acoustic power. In this paper, we introduced theoretic equation between probability density function (PDF) of the transit time in the scan volume and time intensity curve (TIC) measured by FR method. From the equations, it was explained that the mean transit time (MTT) through the scan volume was calculated from the plateau level and tangent of the initial slope.

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RNA editing is a post-transcriptional process that changes individual nucleotides in transcripts, and usually occurs in the plastids of land plants. The number of RNA editing sites in a plastid is significantly divergent in bryophytes, ranging from zero in liverworts to almost 1,000 sites in hornworts. In this study, we identified 132 RNA editing sites in the transcripts of six genes from the psbB operon and the rpoA of the moss Takakia lepidozioides.

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Background And Aims: Non alcoholic steatohepatitis (NASH) is one of the representative liver diseases in the developed countries. Diagnosis of NASH is dependent on histological findings from liver biopsy. Usefulness of contrast ultrasound with Levovist for diagnosis of NASH is described.

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Background: Human obstructive airway diseases are histopathologically characterized by inflammatory cell infiltration, goblet cell hyperplasia, and mucus hypersecretion in airways. We prepared a rat model of airway injury by exposure of sulfur dioxide (SO2) and then evaluated the effects of S-carboxymethylcysteine (S-CMC), a mucoregulant.

Methods: Rats were exposed to SO2 gas for 44 days and orally given S-CMC at 250 mg/kg, twice daily, from 21 to 44 days of exposure for histopathological and immunohistochemical evaluation.

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The C to U editing event that converts an ACG codon to an AUG translation initiation codon in the chloroplast rps 14 transcript is unique to the moss Physcomitrella patens and has not been found in other species. The efficiency of RNA editing was 80% in the young protonemata and decreased to approximately 20% in old protonemata and fully developed leafy shoots. This indicates that RNA editing of this site is regulated in a tissue- and stage-specific manner.

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The rps14 transcript is edited in the moss Physcomitrella patens chloroplast by a C-to-U transition, to create a translation initiation codon, AUG. The efficiency of RNA editing was low, with approximately 20% of rps14 transcripts edited. This suggests that the translation of rps14 mRNA is strictly regulated by RNA editing.

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