Objectives: Excessive sedentary behavior in youth is a major global issue, contributing to the rise in childhood obesity and metabolic diseases. International public health authorities have issued guidelines recommending that children and adolescents limit their daily sedentary time, including screen time. However, to date, no studies have explored the relationship between sedentary behavior as an exposure factor and skeletal muscle strength and mass as outcomes in this population. The present study investigated the association of sedentary behavior with handgrip strength (HGS) and appendicular lean mass (ALM) among United States adolescents. Methods: A total of 1449 adolescent participants from the National Health and Nutrition Examination Survey (2011-2014) were included. Information on sedentary behavior, specifically daily sedentary time, was obtained through a self-reported questionnaire. Muscular parameters, including HGS and ALM, were measured. To adjust for differences in body size, these parameters were divided by body mass index (BMI) and weight. Linear regression analyses were performed to evaluate the associations between daily sedentary time and each muscular parameter, adjusting for age, sex, ethnicity, annual family income, and moderate-to-vigorous physical activity (MVPA). Results: The linear regression analyses revealed negative associations between daily sedentary time and all muscular parameters, apart from absolute ALM. These included HGS (β, -0.265; standard error [SE], 0.074; p=0.001), HGS/BMI (β, -0.021; SE, 0.004; p<0.001), HGS/weight (β, -0.008; SE, 0.002; p<0.001), ALM/BMI (β, -0.008; SE, 0.003; p=0.010), and ALM/weight (β, -0.003; SE, 0.001; p=0.005). Conclusions After adjusting for MVPA, daily sedentary time was inversely associated with HGS, HGS/BMI, HGS/weight, ALM/BMI, and ALM/weight in United States adolescents.

Background: and Purpose: Amyloid-beta (Aβ) plaques are key in Alzheimer’s disease (AD), with Aβ positron emission tomography imaging enabling non-invasive quantification.To address regional Aβ deposition, we developed regional Centiloid scales (rdcCL) and commercialized them through the computed tomography (CT)-based BeauBrain Amylo platform, eliminating the need for three-dimensional T1 magnetic resonance imaging (MRI). Objective: We aimed to establish robust regional Aβ cutoffs using the commercialized BeauBrain Amylo platform and to explore the prevalence of subgroups defined by global, regional, and striatal Aβ cutoffs across cognitive stages. Methods: We included 2,428 individuals recruited from the Korea-Registries to Overcome Dementia and Accelerate Dementia Research project. We calculated regional Aβ cutoffs using Gaussian Mixture Modeling. Participants were classified into subgroups based on global, regional, and striatal Aβ positivity across cognitive stages (cognitively unimpaired [CU], mild cognitive impairment, and dementia of the Alzheimer’s type). Results: MRI-based and CT-based global Aβ cutoffs were highly comparable and consistent with previously reported Centiloid values. Regional cutoffs revealed both similarities and differences between MRI- and CT-based methods, reflecting modality-specific segmentation processes. Subgroups such as global(−)regional(+) were more frequent in non-dementia stages, while global(+)striatal(−) was primarily observed in CU individuals. Conclusions Our study established robust regional Aβ cutoffs using a CT-based rdcCL method and demonstrated its clinical utility in classifying amyloid subgroups across cognitive stages. These findings highlight the importance of regional Aβ quantification in understanding amyloid pathology and its implications for biomarker-guided diagnosis and treatment in AD.

Background: Antithyroid drug (ATD) treatment is the preferred initial treatment for Graves’ disease (GD) in South Korea, despite higher treatment failure rates than radioactive iodine (RAI) therapy or thyroidectomy. This study aimed to evaluate the incidence of treatment failure associated with the primary modalities for GD treatment in real-world practice. Methods: We included 452,001 patients diagnosed with GD between 2004 and 2020 from the Korean National Health Insurance Service-National Health Information Database. Treatment failure was defined as switching from ATD, RAI, or thyroidectomy treatments, and for ATD specifically, inability to discontinue medication for over 2 years. Results: Mean age was 46.2 years, with females constituting 70.8%. Initial treatments for GD included ATDs (98.0%), thyroidectomy (1.3%), and RAI (0.7%), with a noted increment in ATD application from 96.2% in 2004 to 98.8% in 2020. During a median follow- up of 8.5 years, the treatment failure rates were 58.5% for ATDs, 21.3% for RAI, and 2.1% for thyroidectomy. Multivariate analysis indicated that the hazard ratio for treatment failure with ATD was 2.81 times higher than RAI. RAI treatments ≥10 mCi had 37% lower failure rates than doses <10 mCi. Conclusion ATDs are the most commonly used for GD in South Korea, followed by thyroidectomy and RAI. Although the risk of treatment failure for ATD is higher than that of RAI therapy, initial RAI treatment in South Korea is relatively limited compared to that in Western countries. Further studies are required to evaluate the cause of low initial RAI treatment rates in South Korea.

Objectives: Excessive sedentary behavior in youth is a major global issue, contributing to the rise in childhood obesity and metabolic diseases. International public health authorities have issued guidelines recommending that children and adolescents limit their daily sedentary time, including screen time. However, to date, no studies have explored the relationship between sedentary behavior as an exposure factor and skeletal muscle strength and mass as outcomes in this population. The present study investigated the association of sedentary behavior with handgrip strength (HGS) and appendicular lean mass (ALM) among United States adolescents. Methods: A total of 1449 adolescent participants from the National Health and Nutrition Examination Survey (2011-2014) were included. Information on sedentary behavior, specifically daily sedentary time, was obtained through a self-reported questionnaire. Muscular parameters, including HGS and ALM, were measured. To adjust for differences in body size, these parameters were divided by body mass index (BMI) and weight. Linear regression analyses were performed to evaluate the associations between daily sedentary time and each muscular parameter, adjusting for age, sex, ethnicity, annual family income, and moderate-to-vigorous physical activity (MVPA). Results: The linear regression analyses revealed negative associations between daily sedentary time and all muscular parameters, apart from absolute ALM. These included HGS (β, -0.265; standard error [SE], 0.074; p=0.001), HGS/BMI (β, -0.021; SE, 0.004; p<0.001), HGS/weight (β, -0.008; SE, 0.002; p<0.001), ALM/BMI (β, -0.008; SE, 0.003; p=0.010), and ALM/weight (β, -0.003; SE, 0.001; p=0.005). Conclusions After adjusting for MVPA, daily sedentary time was inversely associated with HGS, HGS/BMI, HGS/weight, ALM/BMI, and ALM/weight in United States adolescents.

Purpose: In this study, we investigated the effect of bisphenol-A (BPA) and its major analogs, bisphenol-F (BPF), and bisphenol-S (BPS), on spermatogonial stem cells (SSCs) populations using in vitro SSC culture and in vivo transplantation models. Materials and Methods: SSCs enriched from 6- to 8-day-old C57BL/6-eGFP+ male mice testes were treated with varying concentrations of bisphenols for 7 days to examine bisphenol-derived cytotoxicity and changes in SSC characteristics. We utilized flow cytometry, immunocytochemistry, real-time quantitative reverse transcription-PCR, and western blot analysis. The functional alteration of SSCs was further investigated by examining donor SSC-derived spermatogenesis evaluation through in vivo transplantation and subsequent testis analysis. Results: BPF exhibited a similar inhibitory effect on SSCs as BPA, demonstrating a significant decrease in SSC survival, inhibition of proliferation, and induction of apoptosis. On the other hand, while BPS was comparatively weaker than BPA and BPF, it still showed significant SSC cytotoxicity. Importantly, SSCs exposed to BPA, BPF, and BPS exhibited a significant reduction in donor SSC-derived germ cell colonies per total number of cultured cells, indicating that, like BPA, BPF, and BPS can induce a comparable reduction in functional SSCs in the recipient animals. However, the progress of spermatogenesis, as evidenced by histochemistry and the expressions of PCNA and SSC specific markers, collectively indicates that BPA, BPF, and BPS may not adversely affect the spermatogenesis. Conclusions Our findings indicate that the major BPA substitutes, BPF and BPS, have significant cytotoxic effects on SSCs, similar to BPA. These effects may lead to a reduction in the functional self-renewal stem cell population and potential impacts on male fertility.

Objectives: Excessive sedentary behavior in youth is a major global issue, contributing to the rise in childhood obesity and metabolic diseases. International public health authorities have issued guidelines recommending that children and adolescents limit their daily sedentary time, including screen time. However, to date, no studies have explored the relationship between sedentary behavior as an exposure factor and skeletal muscle strength and mass as outcomes in this population. The present study investigated the association of sedentary behavior with handgrip strength (HGS) and appendicular lean mass (ALM) among United States adolescents. Methods: A total of 1449 adolescent participants from the National Health and Nutrition Examination Survey (2011-2014) were included. Information on sedentary behavior, specifically daily sedentary time, was obtained through a self-reported questionnaire. Muscular parameters, including HGS and ALM, were measured. To adjust for differences in body size, these parameters were divided by body mass index (BMI) and weight. Linear regression analyses were performed to evaluate the associations between daily sedentary time and each muscular parameter, adjusting for age, sex, ethnicity, annual family income, and moderate-to-vigorous physical activity (MVPA). Results: The linear regression analyses revealed negative associations between daily sedentary time and all muscular parameters, apart from absolute ALM. These included HGS (β, -0.265; standard error [SE], 0.074; p=0.001), HGS/BMI (β, -0.021; SE, 0.004; p<0.001), HGS/weight (β, -0.008; SE, 0.002; p<0.001), ALM/BMI (β, -0.008; SE, 0.003; p=0.010), and ALM/weight (β, -0.003; SE, 0.001; p=0.005). Conclusions After adjusting for MVPA, daily sedentary time was inversely associated with HGS, HGS/BMI, HGS/weight, ALM/BMI, and ALM/weight in United States adolescents.

Purpose: In this study, we investigated the effect of bisphenol-A (BPA) and its major analogs, bisphenol-F (BPF), and bisphenol-S (BPS), on spermatogonial stem cells (SSCs) populations using in vitro SSC culture and in vivo transplantation models. Materials and Methods: SSCs enriched from 6- to 8-day-old C57BL/6-eGFP+ male mice testes were treated with varying concentrations of bisphenols for 7 days to examine bisphenol-derived cytotoxicity and changes in SSC characteristics. We utilized flow cytometry, immunocytochemistry, real-time quantitative reverse transcription-PCR, and western blot analysis. The functional alteration of SSCs was further investigated by examining donor SSC-derived spermatogenesis evaluation through in vivo transplantation and subsequent testis analysis. Results: BPF exhibited a similar inhibitory effect on SSCs as BPA, demonstrating a significant decrease in SSC survival, inhibition of proliferation, and induction of apoptosis. On the other hand, while BPS was comparatively weaker than BPA and BPF, it still showed significant SSC cytotoxicity. Importantly, SSCs exposed to BPA, BPF, and BPS exhibited a significant reduction in donor SSC-derived germ cell colonies per total number of cultured cells, indicating that, like BPA, BPF, and BPS can induce a comparable reduction in functional SSCs in the recipient animals. However, the progress of spermatogenesis, as evidenced by histochemistry and the expressions of PCNA and SSC specific markers, collectively indicates that BPA, BPF, and BPS may not adversely affect the spermatogenesis. Conclusions Our findings indicate that the major BPA substitutes, BPF and BPS, have significant cytotoxic effects on SSCs, similar to BPA. These effects may lead to a reduction in the functional self-renewal stem cell population and potential impacts on male fertility.