Publications by authors named "Youngchul Choi"

Background And Purpose: This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM).

Methods: We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with anti-SRP54 antibodies were determined.

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This study presents a method to add a crack analysis algorithm to the Acoustic Leak Monitoring System (ALMS) to detect and evaluate the crack growth process in the primary system piping of nuclear power plants. To achieve this, a fracture test was conducted by applying stepwise loading to welded specimens that simulate the cold leg section, and acoustic emission (AE) signals were measured in relation to the increase in strain using an AE testing system. The experimental results indicated that the stability and instability of cracks could be assessed through the Kaiser effect and the Felicity effect when detecting crack growth using AE signals.

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Acoustic emissions (AEs) are produced by elastic waves generated by damage in solid materials. AE sensors have been widely used in several fields as a promising tool to analyze damage mechanisms such as cracking, dislocation movement, etc. However, accurately determining the location of damage in solids in a non-destructive manner is still challenging.

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Article Synopsis
  • - The study focuses on spinal muscular atrophy (SMA), a genetic disease that results in the loss of motor neurons, leading to muscle weakness, and examines the diagnostic process for Korean SMA patients over 23 years.
  • - In a review of 38 patients, it was found that the average age for symptom onset was 3 years, but diagnosis occurred much later at 25 years, with a notable delay of approximately 19.6 years, particularly longer for type III SMA patients.
  • - The research emphasizes the importance of improving diagnostic accuracy for SMA as treatment options evolve, marking a significant exploration of the diagnostic journey for patients in Korea.
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Background: Facioscapulohumeral muscular dystrophy (FSHD) is a common form of muscular dystrophy that mainly affects skeletal muscle. FSHD1 accounts for 95% of all FSHD cases and can be diagnosed based on the pathogenic contraction of the D4Z4-repeat array on chromosome 4q35. Genetic diagnosis of FSHD1 is challenging because of the large size and repetitive nature of the D4Z4 region.

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Background: Polymyositis (PM) and dermatomyositis (DM) are two distinct subgroups of idiopathic inflammatory myopathies. Dysferlinopathy, caused by a dysferlin gene mutation, usually presents in late adolescence with muscle weakness, degenerative muscle changes are often accompanied by inflammatory infiltrates, often resulting in a misdiagnosis as polymyositis.

Objective: To identify differential biological pathways and hub genes related to polymyositis, dermatomyositis and dysferlinopathy using bioinformatics analysis for understanding the pathomechanisms and providing guidance for therapy development.

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Background And Purpose: Germinal centers (GCs) can be observed in the thymic tissues of patients with thymoma-associated myasthenia gravis (MG). Although an association between thymic GCs and MG has been suggested, it is unknown whether the presence of GCs could predict the development of MG after the resection of thymoma, known as postthymectomy MG.

Methods: We conducted a retrospective analysis of previously nonmyasthenic patients who underwent surgical removal of the thymoma.

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To explore the clinical significance of anti-cytosolic 5'-nucleoditase 1A (NT5c1A) antibody seropositivity in inflammatory myopathies, we measured anti-NT5c1A antibodies and analyzed their clinical features. Anti-NT5c1A antibodies were measured in the sera of 103 patients with inflammatory myopathies using an enzyme-linked immunosorbent assay. Positivity for anti-NT5c1A antibody was found in 13 (12.

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Importance: In the previously reported Comparative Enzyme Replacement Trial With neoGAA Versus rhGAA (COMET) trial, avalglucosidase alfa treatment for 49 weeks showed clinically meaningful improvements in upright forced vital capacity (FVC) percent predicted and 6-minute walk test (6MWT) compared with alglucosidase alfa.

Objective: To report avalglucosidase alfa treatment outcomes during the COMET trial extension.

Design, Setting, And Participants: This phase 3 double-blind randomized clinical trial with crossover in the extension period enrolled patients 3 years and older with previously untreated late-onset Pompe disease (LOPD) between November 2, 2016, and February 10, 2021, with primary analysis after 49 weeks.

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Article Synopsis
  • The study aimed to understand the characteristics of Korean patients with anti-HMGCR myopathy by measuring anti-HMGCR antibodies and analyzing clinical, radiological, and pathological features.
  • Among the 99 patients with inflammatory myopathy, 17 tested positive for anti-HMGCR antibodies, many of whom had taken statins, and the most common symptom reported was proximal muscle weakness.
  • The findings revealed a higher antibody titer in statin-naïve patients compared to those exposed to statins, and also suggested the presence of other myositis-specific autoantibodies in more than half of the patients.
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Bethlem myopathy is one of the collagens VI-related muscular dystrophies caused by mutations in the collagen VI genes. The study was designed to analyze the gene expression profiles in the skeletal muscle of patients with Bethlem myopathy. Six skeletal muscle samples from 3 patients with Bethlem myopathy and 3 control subjects were analyzed by RNA-sequencing.

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Background: Myasthenia gravis (MG) can affect cardiac muscles with variable presentations. Myocarditis is a rare but potentially serious cardiac manifestation of MG. Although thymomas and anti-titin antibodies have been suggested as risk factors for myocarditis in patients with MG, their independent influence on myocarditis has rarely been assessed.

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Background: In patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary interventions (pPCI), longer door-to-balloon (DTB) time is known to be associated with an unfavorable outcome. A percentage of patients with acute coronary occlusion present with atypical electrocardiographic (ECG) findings, known as STEMI-equivalents. We investigated whether DTB time for STEMI-equivalent patients was delayed.

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Background And Purpose: The Individualized Neuromuscular Quality of Life questionnaire (INQoL) is a widely used measure of the quality of life in patients with neuromuscular diseases. The purpose of this study was to translate and validate the Korean version of INQoL in Korean patients with neuromuscular diseases.

Methods: We translated the original INQoL version into Korean while applying appropriate language adaptations.

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A kenaf-derived activated carbon (KAC) for a high-power density supercapacitor was developed in this study through phosphoric acid activation. The N/77K isothermal adsorption-desorption curve was used to estimate the textural properties of KAC based on BET and BJH and the pore size distribution based on NLDFT. The electrochemical properties of KAC were analyzed by using the coin-type cell applying 1 M SPBBF/PC electrolyte, and the specific surface area and total pore volume were 1490-1942 m/g and 1.

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An elbow wall thinning diagnosis method by highlighting the stationary characteristics of the operating loop is proposed. The accelerations of curved pipe surfaces were measured in a closed test loop operating at a constant pump rpm, combined with curved pipe specimens with artificial wall thinning. The vibration characteristics of wall-thinned elbows were extracted by using a mel-spectrogram in which modal characteristic variation shifting can be expressed.

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Introduction: Uric acid and edaravone might exert a neuroprotective effect in amyotrophic lateral sclerosis (ALS) by reducing oxidative stress. We analyzed whether the treatment effect of edaravone is pronounced in patients whose uric acid level increased after the treatment with edaravone.

Materials And Methods: Forty patients with ALS who underwent treatment with edaravone were included.

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Background And Purpose: This study aimed to identify the epidemiological features of Guillain-Barré syndrome (GBS) in the Korean population.

Methods: Patients with GBS were defined as those who were hospitalized with a primary diagnostic code of G61.0 on the Korean Classification of Disease in a department of neurology, rehabilitation medicine, or pediatrics.

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Dystrophinopathy is a group of inherited phenotypes arising from pathogenic variants in DMD. We evaluated the clinical and genetic characteristics of Korean patients with genetically confirmed dystrophinopathy. We retrospectively reviewed medical records (January 2004-September 2020) from the myopathy database maintained at the study hospital and found 227 patients from 218 unrelated families with dystrophinopathy.

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Self-powered wireless sensor systems have emerged as an important topic for condition monitoring in nuclear power plants. However, commercial wireless sensor systems still cannot be fully self-sustainable due to the high power consumption caused by excessive signal processing in a mini-electronic computing system. In this sense, it is essential not only to integrate the sensor system with energy-harvesting devices but also to develop simple data processing methods for low power schemes.

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Article Synopsis
  • * In experiments using muscle cells, increased levels of Nogo-A were tied to higher expression of CHOP and inflammatory cytokines (IL-6 and TNF-α), whereas reducing Nogo-A levels decreased these markers.
  • * Studies on bone marrow-derived macrophages (BMDM) showed that Nogo-A knockout led to lower inflammatory responses and reduced migratory and phagocytic abilities compared to normal macrophages, suggesting its role in muscle inflammation and disease processes.
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Among the three isoforms encoded by Rtn4, Nogo-A has been intensely investigated as a central nervous system inhibitor. Although Nogo-A expression is increased in muscles of patients with amyotrophic lateral sclerosis, its role in muscle homeostasis and regeneration is not well elucidated. In this study, we discovered a significant increase in Nogo-A expression in various muscle-related pathological conditions.

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Hypoxia plays important roles in cancer progression by inducing angiogenesis, metastasis, and drug resistance. However, the effects of hypoxia on long noncoding RNA (lncRNA) expression have not been clarified. Herein, we evaluated alterations in lncRNA expression in lung cancer cells under hypoxic conditions using lncRNA microarray analyses.

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We investigated the clinical, laboratory, and genetic spectra in Korean patients with dysferlinopathy to clarify its genotype-phenotype correlation. We retrospectively reviewed 101 patients from 96 unrelated families with pathogenic variants of DYSF. The most common initial phenotype was Miyoshi myopathy in 50 patients.

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Article Synopsis
  • Charcot-Marie-Tooth disease (CMT) is a genetic disorder affecting the peripheral nervous system, and this study aimed to investigate its prevalence and patient demographics in Korea.
  • Data was collected from 2005-2018, finding a prevalence of 5.2 cases per 100,000 people, with higher rates in men and among those aged 15-39.
  • The research highlighted that 7.8% of patients relied on public assistance, and the standardized mortality ratio indicated that CMT patients experience a higher death rate, particularly due to neurologic diseases compared to the general population.
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