Publications by authors named "Ryosuke Ishida"

Hyperkalemia is a potentially life-threatening condition, particularly in patients with chronic kidney disease (CKD). Potassium-enriched salt substitutes are increasingly promoted as a dietary intervention for hypertension, but may pose risks in patients with impaired renal function. We report the case of an 88-year-old male with CKD who developed asymptomatic but marked hyperkalemia (7.

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Gene mutations resulting in dysfunction of the ryanodine receptor type 2 (RyR2), a huge Ca release channel that controls the concentration of Ca in the cytosol of cardiac muscle cells, can cause fatal heart arrhythmias. However, no RyR2 inhibitors have yet been developed for clinical usage. In this work, we discovered an isoform-selective RyR2 inhibitor 1 with a parabanic acid skeleton by screening a large chemical library.

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Background/aims: Visualization of palisade vessels (PVs) in Barrett's esophagus is crucial for proper assessment. This study aimed to determine whether red dichromatic imaging (RDI) improves PV visibility compared with white-light imaging (WLI) and narrow-band imaging (NBI).

Methods: Five expert and trainee endoscopists evaluated the PV visibility in Barrett's esophagus using WLI, NBI, and RDI on 66 images from 22 patients.

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A 61-year-old woman who had been taking olmesartan for 7 years complained of epigastric pain, diarrhea, loss of appetite, and weight loss. Esophagogastroduodenoscopy revealed roughened mucosa and erosions in the stomach and duodenum. An endoscopic biopsy failed to identify the cause of the mucosal disorder.

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A 71-year-old woman diagnosed with unresectable locally advanced pancreatic cancer was initially treated with gemcitabine and nab-paclitaxel as first-line therapy. The tumor exhibited no significant progression; however, after 12 cycles, the patient developed drug-induced interstitial pneumonia, leading to the discontinuation of gemcitabine and nab-paclitaxel therapy. Following recovery from pneumonia, S-1 therapy was initiated as second-line treatment.

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Article Synopsis
  • A study evaluated the safety and effectiveness of same-day sodium picosulfate plus magnesium citrate (SP + MC) bowel preparation for colonoscopy in 145 Japanese patients, as Japan currently only approves day-before and split-dose methods.
  • Out of 137 patients who had colonoscopies, 97.1% achieved adequate bowel cleansing, with a high mean Boston Bowel Preparation Score, and only five patients experienced minor adverse events.
  • The majority of patients were satisfied with the same-day preparation method, with 99.2% expressing a preference for its use in future colonoscopies, indicating it’s a safe and effective option.
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Ryanodine receptor 2 (RyR2) is a large Ca-release channel in the sarcoplasmic reticulum (SR) of cardiac muscle cells. It serves to release Ca from the SR into the cytosol to initiate muscle contraction. RyR2 overactivation is associated with arrhythmogenic cardiac disease, but few specific inhibitors have been reported so far.

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Article Synopsis
  • EndoTrac is a new traction device designed to improve the control during endoscopic submucosal dissection (ESD) for gastric tumors, though its effectiveness is still under investigation.
  • The G-Trac study is a multicenter trial in Japan that compares conventional ESD with EndoTrac ESD, enrolling patients with superficial gastric neoplasms and measuring outcomes like procedure time and safety.
  • The study has received ethical approval and will share its findings through academic platforms, aiming to involve 142 participants for robust statistical analysis.
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Nuclear factor-B (NF-B) plays a central role in inflammatory responses, and its physiologic functions are essential for cell survival and proliferation. Currently, drugs targeting NF-B inhibition have not yet been applied in clinical practice. We investigated the physiologic effect of a novel NF-B inhibitory compound, 1-pyrazolo[3,4-]pyrimidin-4-amine derivative (INH #1), on three inflammatory animal models.

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Not all encapsulation techniques are universally apt for every type of phase change material (PCM), highlighting the imperative for methodological precision. This study addresses the challenges of microencapsulated PCM (MEPCM) arising from the immiscible pairing of α-AlO nanoparticles with Sn microparticles. The high-speed impact blending (HIB) dry synthesis technique is employed, facilitating large-volume production of Sn@α-AlO MEPCMs.

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Ryanodine receptor 2 (RyR2) is a Ca release channel mainly located on the sarcoplasmic reticulum (SR) membrane of heart muscle cells and regulates the concentration of Ca in the cytosol. RyR2 overactivation causes potentially lethal cardiac arrhythmias, but no specific inhibitor is yet available. Herein we developed the first highly potent and selective RyR2 inhibitor, TMDJ-035, containing 3,5-difluoro substituents on the A ring and a 4-fluoro substituent on the B ring, based on a comprehensive structure-activity relationship (SAR) study of tetrazole compound 1.

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Type 2 ryanodine receptor (RyR2) is a Ca release channel on the endoplasmic (ER)/sarcoplasmic reticulum that plays a central role in the excitation-contraction coupling in the heart. Hyperactivity of RyR2 has been linked to ventricular arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia and heart failure, where spontaneous Ca release via hyperactivated RyR2 depolarizes diastolic membrane potential to induce triggered activity. In such cases, drugs that suppress RyR2 activity are expected to prevent the arrhythmias, but there is no clinically available RyR2 inhibitors at present.

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We herein report a case of severe fever with thrombocytopenia syndrome (SFTS) with Pasteurella multilocida bacteremia in a 65-year-old man with alcoholic cirrhosis who was admitted to our hospital with anorexia and severe fatigue. Laboratory tests revealed pancytopenia and liver and kidney dysfunction. After admission, he developed impaired consciousness, mucosal hemorrhaging, and septic shock.

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All-trans-retinoic Acid (atRA) is the principal active metabolite of Vitamin A, essential for various biological processes. The activities of atRA are mediated by nuclear RA receptors (RARs) to alter gene expression (canonical activities) or by cellular retinoic acid binding protein 1 (CRABP1) to rapidly (minutes) modulate cytosolic kinase signaling, including calcium calmodulin-activated kinase 2 (CaMKII) (non-canonical activities). Clinically, atRA-like compounds have been extensively studied for therapeutic applications; however, RAR-mediated toxicity severely hindered the progress.

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Type 1 ryanodine receptor (RyR1) is an intracellular Ca release channel on the sarcoplasmic reticulum of skeletal muscle, and it plays a central role in excitation-contraction (E-C) coupling. Mutations in RyR1 are implicated in various muscle diseases including malignant hyperthermia, central core disease, and myopathies. Currently, no specific treatment exists for most of these diseases.

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In skeletal muscle excitation-contraction (E-C) coupling, depolarization of the plasma membrane triggers Ca2+ release from the sarcoplasmic reticulum (SR), referred to as depolarization-induced Ca2+ release (DICR). DICR occurs through the type 1 ryanodine receptor (RyR1), which physically interacts with the dihydropyridine receptor Cav1.1 subunit in specific machinery formed with additional essential components including β1a, Stac3 adaptor protein, and junctophilins.

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Ryanodine receptor 1 (RyR1) is a Ca-release channel expressed on the sarcoplasmic reticulum (SR) membrane. RyR1 mediates release of Ca from the SR to the cytoplasm to induce muscle contraction, and mutations associated with overactivation of RyR1 cause lethal muscle diseases. Dantrolene sodium salt (dantrolene Na) is the only approved RyR inhibitor to treat malignant hyperthermia patients with RyR1 mutations, but is poorly water-soluble.

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Type 1 ryanodine receptor (RYR1) is a Ca2+ release channel in the sarcoplasmic reticulum (SR) of the skeletal muscle and plays a critical role in excitation-contraction coupling. Mutations in RYR1 cause severe muscle diseases, such as malignant hyperthermia, a disorder of Ca2+-induced Ca2+ release (CICR) through RYR1 from the SR. We recently reported that volatile anesthetics induce malignant hyperthermia (MH)-like episodes through enhanced CICR in heterozygous R2509C-RYR1 mice.

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Cyclin-dependent kinases (CDK) are attractive targets for drug discovery due to their wide range of cellular functions. CDK11 is an understudied CDK with roles in transcription and splicing, cell cycle regulation, neuronal function, and apoptosis. In this study, we describe a medicinal chemistry campaign to identify a CDK11 inhibitor.

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The most common symptom following the accidental ingestion of a soap is lip edema. Although most cases are asymptomatic or exhibit mild symptoms, in some cases, aspiration pneumonia, oropharyngeal edema, and bronchial obstruction may be fatal.

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Article Synopsis
  • Complex Regional Pain Syndrome (CRPS) transitions from acute to chronic pain and is influenced by TLR4 receptors in myeloid-lineage cells, astrocytes, and neurons, with effects differing by sex.
  • In experiments on mice, early intervention with TLR4 antagonism during injury showed better outcomes for chronic pain, particularly when targeting microglia, demonstrating a significant impact in males and some effect in females.
  • The research highlights that TLR4's role in chronic pain is dependent on timing and cell type, revealing sex differences in how myeloid cells contribute to pain progression.
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Beta-catenin-activated hepatocellular adenoma is potentially malignant and warrants careful follow-up and surgical resection. Here, we report a 48-year-old man in whom a 55 mm single liver tumor was incidentally detected in the S1 segment. Contrast-enhanced computed tomography scans showed no enhancement in the early phase and a slight defection in the late phase.

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  • Orthopedic injuries can result from various incidents like car accidents or falls, leading to persistent pain and complex damage to bones, muscles, and nerves.
  • The review focuses on understanding how these injuries affect different tissues, specifically using rodent models to study trauma effects on bones, muscles, and nerves.
  • It covers methods for assessing healing in bones, muscle regeneration, and pain responses, while drawing comparisons to human conditions to guide treatment development.
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Synopsis of recent research by authors named "Ryosuke Ishida"

  • - Ryosuke Ishida's recent research includes clinical studies focused on improving treatments for various conditions, such as the administration of S-1 for pancreatic cancer and evaluating the efficacy of novel bowel preparation methods for colonoscopy.
  • - Significant advancements in drug discovery are highlighted through the development of selective inhibitors for ryanodine receptor 2 (RyR2), which has implications for cardiac arrhythmia treatment, underscoring the importance of structure-activity relationship studies in pharmacology.
  • - His work also covers innovative techniques in endoscopic procedures, aiming to enhance the efficacy and safety of treatments for gastrointestinal neoplasms while addressing the challenges presented by existing methods.