Prevalence and associated factors of locomotive syndrome in young Japanese adults: a cross-sectional study.

BACKGROUND: The onset of locomotive syndrome (LS) precedes that of frailty. Therefore, the first step in extending healthy life expectancy is to implement measures against LS in young adults. The aim of this study was to investigate the prevalence of LS and its associated factors in young adults for early detection and prevention of LS. METHODS: The participants of this study comprised 413 university students specializing in health sciences (192 males and 221 females) with an average age of 19.1 ± 1.2 years. All participants voluntarily participated in the study and reported no serious health problems. The presence or absence of LS was evaluated using the stand-up test, two-step test, and the 25-question Geriatric Locomotive Function Scale. Additionally, musculoskeletal assessment (one-leg standing, squatting, shoulder elevation, and standing forward bend), body composition analysis (weight, body mass index, body fat mass, body fat percentage, skeletal muscle mass index (SMI), and phase angle), handgrip strength test, physical activity assessment, and nutritional assessment were conducted. Sex-stratified analyses were performed, comparing groups with and without LS. Factors associated with LS were explored using binomial logistic regression. RESULTS: Of the 413 young adults studied, 86 individuals (20.8%) were found to have LS. When stratified by sex, LS was observed to have a considerably higher prevalence in females (55, 24.9%) than in males (31, 16.1%). In males, the notable differences between the groups with and without LS were observed in one-leg standing and phase angle, whereas in females, differences were identified in body fat mass, body fat percentage, SMI, musculoskeletal pain, and handgrip strength. Two types of binomial logistic regression analysis revealed that the inability to perform one-leg standing was associated with LS in males, while the presence of musculoskeletal pain and a high body fat percentage were identified as factors associated with LS in females. CONCLUSIONS: One in five young adults were found to have LS in this study, underscoring the necessity for early intervention and LS health education. Furthermore, effective management of musculoskeletal pain is also crucial.

Factors associated with discrepancies in disease activity as assessed by SDAI and RAPID3 in patients with rheumatoid arthritis: Data from a multicenter observational study (T-FLAG).

OBJECTIVES: The present study aimed to examine discrepancies between assessments based on Routine Assessment of Patient Index Data 3 (RAPID3) and Simple Disease Activity Index (SDAI) in RA patients with controlled disease activity. METHODS: Data from 464 RA patients in SDAI remission or low disease activity (REM/LDA) were analyzed. Patient-reported outcome (PRO) measures, including Health Assessment Questionnaire Disability Index (HAQ-DI), 25-question Geriatric Locomotive Function Scale (GLFS-25), and Kihon checklist (KCL), were assessed. Logistic regression models were used to identify factors associated with RAPID3 moderate or high disease activity (MDA/HDA). Cutoff values of RAPID3 MDA/HDA for each PRO evaluation item were determined using receiver operating characteristic curve analysis. RESULTS: Among RA patients in SDAI REM/LDA, 84.9% were in RAPID3 REM/LDA. Multivariable analysis revealed that HAQ-DI, GLFS-25, and KCL were independently associated with RAPID3 MDA/HDA. Subdomain analysis of KCL revealed that activities of daily living, physical function, cognitive function, and depressive mood were significantly associated with RAPID3 MDA/HDA. Cutoff values for HAQ-DI and KCL were 0.38 and 8, respectively. CONCLUSIONS: In RA patients with controlled disease activity, discrepancies between RAPID3 and SDAI assessments were observed, with factors such as HAQ-DI, GLFS-25, and KCL being independently associated with RAPID3 MDA/HDA.

Artificial intelligence for volumetric measurement of cerebral white matter hyperintensities on thick-slice fluid-attenuated inversion recovery (FLAIR) magnetic resonance images from multiple centers.

We aimed to develop a new artificial intelligence software that can automatically extract and measure the volume of white matter hyperintensities (WMHs) in head magnetic resonance imaging (MRI) using only thick-slice fluid-attenuated inversion recovery (FLAIR) sequences from multiple centers. We enrolled 1092 participants in Japan, comprising the thick-slice Private Dataset. Based on 207 randomly selected participants, neuroradiologists annotated WMHs using predefined guidelines. The annotated images of participants were divided into training (n = 138) and test (n = 69) datasets. The WMH segmentation model comprised a U-Net ensemble and was trained using the Private Dataset. Two other models were trained for validation using either both thin- and thick-slice MRI datasets or the thin-slice dataset alone. The voxel-wise Dice similarity coefficient (DSC) was used as the evaluation metric. The model trained using only thick-slice MRI showed a DSC of 0.820 for the test dataset, which is comparable to the accuracy of human readers. The model trained with the additional thin-slice dataset showed only a slightly improved DSC of 0.822. This automatic WMH segmentation model comprising a U-Net ensemble trained on a thick-slice FLAIR MRI dataset is a promising new method. Despite some limitations, this model may be applicable in clinical practice.

An Improved Data Processing Algorithm for Spectrally Resolved Interferometry Using a Femtosecond Laser.

Spectrally resolved interferometry utilizing a femtosecond laser is widely employed for absolute distance measurement. However, deviations in the output time pulse of the conventional algorithm through inverse Fourier transform are inevitable. Herein, an improved data processing algorithm employing a time-shifting parameter is proposed to improve the accuracy of spectrally resolved interferometry. The principle of the proposed time-shifting algorithm is analyzed theoretically after clarifying the deviation source of the conventional algorithm. Simulation and experimental work were conducted to indicate the improvement in the accuracy of the output absolute distance. The results demonstrated that the proposed algorithm could reduce the deviation of output distances towards the reference values, reaching 0.58 µm by half compared to the conventional algorithm. Furthermore, the measurement uncertainty was evaluated using the Guide to the Expression of Uncertainty in Measurement (GUM), resulting in an expanded uncertainty of 0.71 µm with a 95% confidence.

Vascular smooth muscle cell-derived nerve growth factor regulates sympathetic collateral branching to innervate blood vessels in embryonic skin.

Blood vessels serve as intermediate conduits for the extension of sympathetic axons towards target tissues, while also acting as crucial targets for their homeostatic processes encompassing the regulation of temperature, blood pressure, and oxygen availability. How sympathetic axons innervate not only blood vessels but also a wide array of target tissues is not clear. Here we show that in embryonic skin, after the establishment of co-branching between sensory nerves and blood vessels, sympathetic axons invade the skin alongside these sensory nerves and extend their branches towards these blood vessels covered by vascular smooth muscle cells (VSMCs). Our mosaic labeling technique for sympathetic axons shows that collateral branching predominantly mediates the innervation of VSMC-covered blood vessels by sympathetic axons. The expression of nerve growth factor (NGF), previously known to induce collateral axon branching in culture, can be detected in the vascular smooth muscle cell (VSMC)-covered blood vessels, as well as sensory nerves. Indeed, VSMC-specific Ngf knockout leads to a significant decrease of collateral branching of sympathetic axons innervating VSMC-covered blood vessels. These data suggest that VSMC-derived NGF serves as an inductive signal for collateral branching of sympathetic axons innervating blood vessels in the embryonic skin.

Ultrasonic humidifier lung with a reversed halo sign: A case report.

The reversed halo sign was initially reported as a representative computed tomography scan finding of cryptogenic organizing pneumonia. Since then, however, it has been reported in various diseases and is now considered a nonspecific finding. However, there are no cases of humidifier lung with the reversed halo sign. An 82-year-old Japanese male patient presented with moving difficulties 48 days after starting darolutamide treatment for prostate cancer. He was admitted to the hospital due to acute pneumonia, which presented as bilateral extensive nonsegmental ground-glass opacities in the peripheral regions and extensive areas of ground-glass opacity with a circumferential halo of consolidation, with the reversed halo sign on computed tomography scan. After darolutamide discontinuation with the concomitant administration of antibiotics, the patient's pneumonia improved, and he was discharged from the hospital. However, within a few days, he was again admitted to the hospital due to pneumonia. He was found to have been using an ultrasonic humidifier at home and was then diagnosed with humidifier lung based on the bronchoscopy and provocative testing findings. Hence, ultrasonic humidifier lung should be considered as a differential diagnosis in patients presenting with the reversed halo sign, and a detailed medical history must be taken.

Bone and soft tissue reconstruction with tendon balance in severe foot trauma.

In severe foot trauma, it is difficult to determine the level of amputation when the crush injury is severe. We report a case of amputation near Lisfranc that achieved forefoot amputation-like results by using bone and soft tissue reconstruction while considering tendon balance. The patient was a 40-year-old male. The patient's left leg was caught in a garbage truck and sustained a crush injury. The second to fifth metatarsals were amputated at the diaphysis, and a high degree of instability of the Lisfranc joint was observed. A high degree of contamination was detected in the patient's wound, and the second to fifth toes were amputated at the Lisfranc joint during the initial treatment. The ends of the tibialis anterior, tibialis posterior and peroneus longus were preserved. On day 5 in the hospital, Lisfranc joint fixation of the hallux, amputation of the first metatarsal and reconstruction of the peroneus brevis were performed. On day 13, extensor hallucis longus tendon transfer and free anterolateral thigh flap were performed. On day 80, the patient was able to walk in regular shoes or non-orthopedic shoes. One year after reconstructive surgery, the patient had an average SAFE-Q score of 86.2 and mild varus deformity of the foot remained. In cases of severe foot trauma, the aim of reconstruction should be partial forefoot amputation whenever possible.

Antimicrobial therapy outcomes in acute cholangitis: Hilar multiple obstructions versus single hilar and common bile duct obstructions.

Background and Aim: The appropriate duration of antimicrobial therapy for acute cholangitis (AC) arising from multiple hilar biliary obstructions as opposed to simple obstruction in the extrahepatic bile duct has not been established. This study assessed the efficacy of the duration of antimicrobial treatments in the Tokyo Guidelines 2018 for AC based on the cause and site of obstruction. Methods: This single-center retrospective study involved patients with AC who underwent successful biliary drainage and completed a 7-day or shorter antimicrobial treatment. Patients were categorized into three groups: Group 1, bile duct stone or benign obstruction; Group 2, simple biliary obstruction due to malignancy; and Group 3, multiple hilar biliary obstruction due to malignancy. The primary outcome was clinical cure rate, and the secondary outcomes were 3-month recurrence rate and length of hospital stay. Results: A total of 373 patients were selected. Patients in Group 3 were younger or had Charlson Comorbidity Index ≥4, and had fewer positive blood cultures. In Group 3, the clinical cure rate (87.1%) and 3-month recurrence rate (32.3%) were less favorable than those in the other groups. In Group 1, the clinical cure rate was significantly higher (98.1%, P = 0.02) with a much lower 3-month recurrence rate of only 3.4% (P < 0.001) than that in the other groups. The median hospital stay for all groups was 7 days. Conclusion: This study suggests that the outcomes in Group 3 may be worse than those in Groups 1 or 2, regardless of the duration of the antibiotic treatment.

Assessment of Therapeutic Effects of Combined Treatment With Cisplatin and Anti-mouse Programmed Death (PD)-1 Antibody in a Mouse Urothelial Cancer Model.

BACKGROUND/AIM: The therapeutic impact of combination treatment with an immune checkpoint inhibitor (ICI) and chemotherapeutic agent on patients with urothelial cancer (UC) remains controversial. Therefore, the present study investigated differences in the therapeutic effects of combination therapy with cisplatin plus anti-mouse programmed death (PD)-1 antibody according to the dose of cisplatin using the mouse bladder tumor model MBT2. MATERIALS AND METHODS: The effects of treatment with two different doses cisplatin and/or anti-mouse PD-1 antibody on tumor growth after the subcutaneous injection of MBT2 cells were compared. Infiltrating patterns of lymphocytes into tumors after treatment were assessed using immunohistochemical staining. RESULTS: MBT2 tumor volumes were significantly larger in mice receiving high-dose cisplatin alone than in those receiving low-dose cisplatin alone. Combination treatment with cisplatin plus anti-mouse PD-1 antibody exerted significantly stronger growth inhibitory effects on MBT2 tumors than treatment with either agent alone, irrespective of cisplatin doses; however, no significant differences were observed in MBT2 tumor volumes between mice receiving anti-mouse PD-1 antibody plus high-dose cisplatin and those receiving anti-mouse PD-1 antibody plus low-dose cisplatin. Furthermore, CD8+ to CD3+ and CD8+ to CD11b+ T-lymphocyte ratios in MBT2 tumors were both significantly higher in the low-dose cisplatin alone group than in the high-dose cisplatin alone group, whereas no significant differences were noted in either ratio between the two different combination treatment regimens. CONCLUSION: When combined with ICI, a lower dose of cisplatin may achieve favorable antitumor effects in UC patients by preventing lymphocyte exhaustion.

Engineering the Propeptide of Microbial Transglutaminase Zymogen: Enabling Substrate-Dependent Activation for Bioconjugation Applications.

Microbial transglutaminase (MTG) from Streptomyces mobaraensis is a powerful biocatalytic glue for site-specific cross-linking of a range of biomolecules and synthetic molecules that have an MTG-reactive moiety. The preparation of active recombinant MTG requires post-translational proteolytic digestion of a propeptide that functions as an intramolecular chaperone to assist the correct folding of the MTG zymogen (MTGz) in the biosynthesis. Herein, we report engineered active zymogen of MTG (EzMTG) that is expressed in soluble form in the host Escherichia coli cytosol and exhibits cross-linking activity without limited proteolysis of the propeptide. We found that the saturation mutagenesis of residues K10 or Y12 in the propeptide domain generated several active MTGz mutants. In particular, the K10D/Y12G mutant exhibited catalytic activity comparable to that of mature MTG. However, the expression level was low, possibly because of decreased chaperone activity and/or the promiscuous substrate specificity of MTG, which is potentially harmful to the host cells. The K10R/Y12A mutant exhibited specific substrate-dependent reactivity toward peptidyl substrates. Quantitative analysis of the binding affinity of the mutated propeptides to the active site of MTG suggested an inverse relationship between the binding affinity and the catalytic activity of EzMTG. Our proof-of-concept study provides insights into the design of a new biocatalyst using the MTGz as a scaffold and a potential route to high-throughput screening of EzMTG mutants for bioconjugation applications.

Clinical Efficacy and Body Composition Changes with Sodium Glucose Cotransporter 2 Inhibitor/Glucagon-like Peptide-1 Antagonist Combination Therapy in Patients with Type 2 Diabetes Mellitus-associated Nonalcoholic Fatty Liver Disease.

Objective Nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NAFLD/NASH) treatment guidelines recommend sodium glucose cotransporter 2 inhibitor (SGLT2I) and glucagon-like peptide-1 agonist (GLP-1A) therapy in patients with type 2 diabetes mellitus (T2DM). SGLT2I improves the pathological condition of NAFLD/NASH in T2DM patients. However, cases of rebound during long-term SGLT2I treatment have been reported. This study investigated the efficacy of SGLT2I and GLP-1A combination therapy in diabetic patients with NAFLD by examining changes in computed tomography (CT)-based body composition and clinical outcomes. Methods Fifteen patients (5 men/10 women) with T2DM-associated NAFLD who had not responded to SGLT2I treatment and were being treated with GLP-1A combination therapy were included. Changes in the liver function, visceral adipose tissue index (VATI), and subcutaneous adipose tissue index (SATI) were compared using CT to evaluate the body composition. Results SGLT2I significantly improved alanine aminotransferase (28.0 to 13.0 IU/L), alkaline phosphatase (250.0 to 77.0 IU/L), and gamma glutamyl transpeptidase (23.0 to 12.0 IU/L) levels. The body mass index (BMI) decreased from 25.7 to 25.2 kg/m2. A CT-based analysis showed a significant improvement in SATI (80.9 to 66.1, p=0.002), with no significant change in VATI (53.2 to 51.5). GLP-1A addition improved the BMI (25.2 to 23.5 kg/m2) and hemoglobin A1c (6.5% to 6.2%, p=0.001). A further analysis revealed additional improvement in SATI (66.1 to 56.6, p=0.007) and a significant decrease in VATI (51.5 to 48.3, p=0.001). Conclusion SGLT2I and GLP-1A combination therapy improved the liver function, body composition, and glycemic control in diabetic patients with NAFLD/NASH, as well as SATI and VATI. The optimal timing of combination therapy remains to be determined.

Association of short-course antimicrobial therapy and bacterial resistance in acute cholangitis: Retrospective cohort study.

Background and study aims Although the number of resistant bacteria tends to increase with prolonged antimicrobial therapy, no studies have examined the relationship between the duration of antimicrobial therapy and increase in the number of resistant bacteria in acute cholangitis. We hypothesized that the short-term administration of antimicrobial agents in acute cholangitis would suppress bacterial resistance. Patients and methods This was a single-center, retrospective, observational study of patients with acute cholangitis admitted between January 2018 and June 2020 who met the following criteria: successful biliary drainage, positive blood or bile cultures, bacteria identified from cultures sensitive to antimicrobials, and subsequent cholangitis recurrence by January 2022. The patients were divided into two groups: those whose causative organisms at the time of recurrence became resistant to the antimicrobial agents used at the time of initial admission (resistant group) and those who remained susceptible (susceptible group). Multivariate analysis was used to examine risk factors associated with the development of resistant pathogens. Multivariate analysis investigated antibiotics used with the length of 3 days or shorter after endoscopic retrograde cholangiopancreatography (ERCP) and previously reported risk factors for the development of bacterial resistance. Results In total, 89 eligible patients were included in this study. There were no significant differences in patient background or ERCP findings between the groups. The use of antibiotics, completed within 3 days after ERCP, was associated with a lower risk of developing bacterial resistance (odds ratio, 0.17; 95% confidence interval, 0.04-0.65; P =0.01). Conclusions In acute cholangitis, the administration of antimicrobials within 3 days of ERCP may suppress the development of resistant bacteria.

Neck circumference is a highly reliable anthropometric measure in older adults requiring long-term care.

The reliability of neck circumference measurement as an assessment tool for older adults requiring long-term care remains unknown. This study aimed to evaluate the reliability of neck circumference measurement in older adults requiring long-term care, and the effect of edema on measurement error. Two physical therapists measured the neck circumference. Intraclass correlation coefficient (ICC) and Bland-Altman analyses were performed to examine the reliability of neck circumference measurement. Correlation analysis was used to evaluate the relationship between edema values (extracellular water/total body water) and neck circumference measurement difference. For inter-rater reliability of neck circumference measurement, the overall ICC (2,1) was 0.98. The upper and lower limits of the difference between examiners ranged from -0.9 to 1.2 cm. There was no association between edema values and neck circumference measurement error. Thus, measurement of the neck circumference in older adults requiring long-term care is a reliable assessment tool, with a low error rate, even in older adults with edema.

Relationship Between Adverse Events and Progression-free Survival in Patients Receiving Cabozantinib for Previously Treated Metastatic Renal Cell Carcinoma.

BACKGROUND/AIM: Although the adverse events (AEs) of drugs, such as sunitinib and axitinib, have been shown to predict treatment responses, evidence to support cabozantinib-induced AEs as predictors of responses to treatment for metastatic renal cell carcinoma (mRCC) is limited. Therefore, we herein investigated the relationship between AE profiles and progression-free survival (PFS) in patients receiving cabozantinib for previously treated mRCC. PATIENTS AND METHODS: The present study retrospectively analyzed 40 patients receiving cabozantinib for previously treated mRCC between July 2020 and August 2022. PFS was estimated using the Kaplan-Meier method and the impact of several parameters, including cabozantinib-induced AEs, on PFS was investigated by a Cox proportional regression analysis. RESULTS: The median observation period was 15 (2-29) months, during which time 31 patients (77.5%) progressed, with median PFS of 11 months. Thirty-nine patients (97.5%) developed at least one AE. Liver toxicity occurred in 16 patients (40.0%) and hand-foot syndrome, hypertension, and diarrhea in 14 each (17.5%). Only hypertension correlated with longer PFS. A multivariate analysis identified hypertension as an independent prognostic factor for PFS (p=0.049). CONCLUSION: These results suggest the potential of treatment-induced hypertension as a significant predictor of prolonged PFS in patients receiving cabozantinib for mRCC.

Cross-vendor multiparametric mapping of the human brain using 3D-QALAS: A multicenter and multivendor study.

PURPOSE: To evaluate a vendor-agnostic multiparametric mapping scheme based on 3D quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse (3D-QALAS) for whole-brain T1, T2, and proton density (PD) mapping. METHODS: This prospective, multi-institutional study was conducted between September 2021 and February 2022 using five different 3T systems from four prominent MRI vendors. The accuracy of this technique was evaluated using a standardized MRI system phantom. Intra-scanner repeatability and inter-vendor reproducibility of T1, T2, and PD values were evaluated in 10 healthy volunteers (6 men; mean age ± SD, 28.0 ± 5.6 y) who underwent scan-rescan sessions on each scanner (total scans = 100). To evaluate the feasibility of 3D-QALAS, nine patients with multiple sclerosis (nine women; mean age ± SD, 48.2 ± 11.5 y) underwent imaging examination on two 3T MRI systems from different manufacturers. RESULTS: Quantitative maps obtained with 3D-QALAS showed high linearity (R2 = 0.998 and 0.998 for T1 and T2, respectively) with respect to reference measurements. The mean intra-scanner coefficients of variation for each scanner and structure ranged from 0.4% to 2.6%. The mean structure-wise test-retest repeatabilities were 1.6%, 1.1%, and 0.7% for T1, T2, and PD, respectively. Overall, high inter-vendor reproducibility was observed for all parameter maps and all structure measurements, including white matter lesions in patients with multiple sclerosis. CONCLUSION: The vendor-agnostic multiparametric mapping technique 3D-QALAS provided reproducible measurements of T1, T2, and PD for human tissues within a typical physiological range using 3T scanners from four different MRI manufacturers.

Enhanced Data-Processing Algorithms for Dispersive Interferometry Using a Femtosecond Laser.

Dispersive interferometry based on a femtosecond laser is extensively utilized for achieving absolute distance measurements with high accuracy. However, this method cannot measure arbitrary distances without encountering a dead zone, and deviations in its output results are inevitable due to inherent theory limitations. Therefore, two enhanced data-processing algorithms are proposed to improve the accuracy and reduce the dead zone of dispersive interferometry. The principles of the two proposed algorithms, namely the truncated-spectrum algorithm and the high-order-angle algorithm, are proposed after explaining the limitations of conventional methods. A series of simulations were conducted on these algorithms to show the improved accuracy of measurement results and the elimination of the dead zone. Furthermore, an experimental setup based on a dispersive interferometer was established for the application of these proposed algorithms to the experimental interference spectral signals. The results demonstrated that compared with the conventional algorithm, the proposed truncated-spectrum algorithm could reduce the output distance deviations derived from direct inverse Fourier transforming by eight times to reach as low as 1.3 µm. Moreover, the unmeasurable dead zone close to the zero position of the conventional algorithm, i.e., the minimum working distance of a dispersive interferometer, could be shortened to 22 µm with the implementation of the proposed high-order-angle algorithm.

Association between laughter, frailty, and depression in rheumatoid arthritis patients.

OBJECTIVE: This study aimed to determine whether there are associations between laughter, disease activity, frailty, and depression in rheumatoid arthritis (RA) patients. METHODS: A total of 240 patients were included in this prospective cohort study on frailty in RA patients between March 2021 and June 2022. Patients were divided into the following four groups according to the frequency of laughter: "almost every day," "1-5 days per week," "1-3 days per month," and "never or almost never." Patient characteristics were compared among the four groups by analysis of variance. Factors associated with laughter were identified by multivariable logistic analysis. RESULTS: The mean 28-joint Disease Activity Score using CRP was 1.91, with 70.7% of patients in remission and 12.6% in low disease activity. For the "almost every day" (42.5% of patients), "1-5 days per week" (40.0%), "1-3 days per month" (11.3%), and "never or almost never" (6.3%) groups, scores of the Kihon Checklist (KCL) for assessing frailty status were 3.5, 4.6, 7.3, and 8.1 (p < .001), respectively, and scores of the Beck Depression Inventory (BDI-II) were 8.4, 10.7, 15.1, and 16.5 (p < .001), respectively. Multivariable analysis revealed that KCL (OR: 0.81, 95% CI: 0.73-0.90) and BDI-II (OR: 0.91, 95% CI: 0.86-0.95) scores were independently associated with the frequency of laughter. CONCLUSION: Frailty and depression were associated with laughter in RA patients with controlled disease activity. Interventions aimed at not only disease activity control but also frailty prevention may lead to a life filled with laughter.

The Clinical Course and Treatment of a Case of Refractory Systemic Juvenile Myasthenia Gravis Successfully Treated with Thymectomy.

Juvenile myasthenia gravis (JMG) exhibits a more favorable response to glucocorticoids and has a better prognosis than adult myasthenia gravis. However, no established treatment exists for refractory JMG. Although thymectomy has been performed in several patients with refractory systemic JMG, there are few detailed clinical descriptions of patients who underwent thymectomy. Here, we present the case of a 10-year-old boy with refractory systemic JMG who was successfully treated with thymectomy. The patient developed symptoms, including dysphagia, malaise, diurnal ptosis, and weakness in the trunk muscles, and he was diagnosed with generalized JMG. Despite undergoing various treatments, including steroids, tacrolimus, steroid pulse therapy, intravenous immunoglobulin, azathioprine (AZT), and rituximab, his symptoms did not improve. Therefore, he underwent a thoracoscopic thymectomy 24 months after disease onset. Thymectomy led to remission, as demonstrated by a significant reduction in the quantitative myasthenia gravis score and anti-acetylcholine receptor antibody levels, which persisted for 43 months after surgery. Our case demonstrates the effectiveness of thymectomy in systemic JMG patients with positive anti-acetylcholine receptor antibodies, despite therapeutic failure with AZT and rituximab, within 2 years of disease onset.