Publications by authors named "Megumi Hirayama"

Article Synopsis
  • This study investigates how to differentiate between pseudoureterocele and ureterocele using ultrasound imaging in patients with duplex collecting systems exhibiting intravesical cystic lesions.
  • Nineteen patients were analyzed, and the researchers compared ultrasound findings like the presence of a muscular layer and a "notch sign" in these lesions.
  • Significant differences were found in the characteristics of the lesions, aiding in accurate diagnosis and treatment planning for ectopic ureters and ureteroceles in children.
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  • * This study conducted detailed glycomic analyses and found that blood group-specific antigens mainly reside on glycosphingolipids in lipoproteins rather than on glycoproteins, and their presence is influenced by blood type and secretor status.
  • * The research also identified low-molecular-weight blood group-specific glycans in both serum/plasma and cerebrospinal fluid, offering new insights into their structures and distributions across different biological fluids.
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Aim: Liver biopsy is still required for the diagnosis of hepatocellular ballooning and inflammation, which are important histological features of non-alcoholic steatohepatitis. We undertook this multicenter, cross-sectional study to identify novel blood markers for the diagnosis of hepatocellular ballooning.

Methods: We enrolled 176 patients, of whom 132 were proven by liver biopsy as having non-alcoholic fatty liver disease (NAFLD) and classified as non-ballooning (ballooning grade 0) (n = 83) or ballooning (ballooning grade 1 and 2) (n = 49) by a central pathology review.

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Intracellular DNA triggers interferon release during the innate immune response. Cyclic GMP-AMP synthase (cGAS) senses intracellular double-stranded DNA not only in response to viral infection but also under autoimmune conditions. Measuring the levels of cyclic GMP-AMP (cGAMP) as a second messenger of cGAS activation is important to elucidate the physiological and pathological roles of cGAS.

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Objective To identify organizational barriers to and facilitators for female surgeons' career progression. Design Systematic review of qualitative and quantitative studies relating to organizational barriers to and facilitators for female Surgeons' career progression. After the quality assessment of the peer-reviewed journal articles, twelve articles were selected for full review.

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We pursued serine palmitoyltransferase (SPT) inhibitors as novel cancer therapeutic agents based on a correlation between SPT inhibition and growth suppression of cancer cells. High-throughput screening and medicinal chemistry efforts led to the identification of structurally diverse SPT inhibitors 4 and 5. Both compounds potently inhibited SPT enzyme and decreased intracellular ceramide content.

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In the past decade, various lipidomics methodologies have been developed using mass spectrometry based analytical technologies, enabling wide coverage lipid detection in a quantitative manner. Hence, lipidomics has become a widely-accepted approach for biomarker discovery and mechanism elucidation in both medical and biology research fields; however, there are still technical challenges. In this study, focusing on the sample preparation procedure, a single step deproteinization by a water-soluble organic solvent, such as methanol (MeOH), ethanol (EtOH), isopropanol (IPA) or acetonitrile (ACN), was evaluated and proved to be satisfactory for lipidomics analysis.

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A lead compound A was identified previously as an stearoyl coenzyme A desaturase (SCD) inhibitor during research on potential treatments for obesity. This compound showed high SCD1 binding affinity, but a poor pharmacokinetic (PK) profile and limited chemical accessibility, making it suboptimal for use in anticancer research. To identify potent SCD1 inhibitors with more promising PK profiles, we newly designed a series of 'non-spiro' 4, 4-disubstituted piperidine derivatives based on molecular modeling studies.

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Most cancer cells are characterized by elevated lipid biosynthesis. The rapid proliferation of cancer cells requires de novo synthesis of fatty acids. Stearoyl-CoA desaturase-1 (SCD1), a key enzyme for lipogenesis, is overexpressed in various types of cancer and plays an important role in cancer cell proliferation.

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Metabolic reprogramming is an essential hallmark of neoplasia. Therefore, targeting cancer metabolism, including lipid synthesis, has attracted much interest in recent years. Serine palmitoyltransferase (SPT) plays a key role in the initial and rate-limiting step of de novo sphingolipid biosynthesis, and inhibiting SPT activity prevents the proliferation of certain cancer cells.

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  • Both exercise and calorie restriction (CR) are common strategies for weight loss, but their effects on metabolic health and insulin sensitivity remain debated.
  • In an experiment with 35 male Fischer F344 rats, different groups underwent exercise or varying levels of calorie restriction over 4 weeks after being fed a high-fat diet for 4 months.
  • Results indicated that while CR was more effective for weight loss, exercise had a greater impact on reducing fat in the body and improving insulin sensitivity, suggesting complementary benefits of both interventions.
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Monoacylglycerol O-acyltransferase 2 (MGAT2) catalyzes the synthesis of diacylglycerol (DG), a triacylglycerol precursor and potential peripheral target for novel anti-obesity therapeutics. High-throughput screening identified lead compounds with MGAT2 inhibitory activity. Through structural modification, a potent, selective, and orally bioavailable MGAT2 inhibitor, compound A (compA), was discovered.

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Calcitonin gene-related peptide (CGRP) is thought to be a prominent neuropeptide in cardiovascular regulation and neuroimmune modulation. There are two isoforms of CGRP (alphaCGRP and betaCGRP), and the main CGRP receptors are probably composed of a calcitonin receptor-like receptor (CLR) and a receptor activity-modifying protein (RAMP)1. However, the physiological functions of CGRP that are mediated through the CLR/RAMP1 receptors remain to be clarified.

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