Regular physical activity is an important component of physical health of children and has been associated with increasing skeletal muscle mass and muscle strength. Children with low levels of ...physical activity may experience health problems, such as loss of muscle mass, later in life. Thus, it may be valuable to identify declining physical function in children who do not perform the recommended amount of physical activity. Therefore, we aimed to evaluate the relationship between the amount of physical activity performed for greater than or equal to60 min per day for greater than or equal to5 days per week and the skeletal muscle mass index and physical function in young children. In total, 340 typically developing children aged 6-12 years (175 girls; average age, 9.5±1.9 years) were included in this cross-sectional study. We evaluated the proportion of children performing the recommended minimum of 60 min of daily moderate-to-vigorous physical activity at least 5 days per week. The skeletal muscle mass and Gait Deviation Index scores, gait speed, grip strength, Five Times Sit-to-Stand test results, Timed Up-and-Go test results, one-leg standing time, and gait efficiency were evaluated. Multiple logistic regression analyses were performed to assess the association of moderate-to-vigorous physical activity with the skeletal muscle mass index, percent body fat, and physical function, after controlling for confounding factors (age and sex). A logistic regression analysis revealed that the skeletal muscle mass index was independently associated with moderate-to-vigorous physical activity (odds ratio, 2.34; 95% confidence interval, 1.17-4.71; P = 0.017). Performance of moderate-to-vigorous physical activity for greater than or equal to5 days per week for greater than or equal to60 min per day was associated with the skeletal muscle mass index score of Japanese children. Our findings highlighted the importance of performing moderate-to-vigorous physical activity for the development of skeletal muscle mass in children.
Beta-band (15–30 Hz) corticomuscular and intermuscular coherences are important markers of the corticospinal interaction. The purpose of this study was to investigate whether amount of visual ...feedback during an isometric pinch grip contraction would influence these coherences in young and elderly adults. Thirty-three healthy young and elderly subjects performed pinch grip force-matching task with right thumb and index finger, while scalp electroencephalogram (EEG) and electromyogram (EMG) from the first dorsal interosseous (FDI) and abductor pollicis brevis (APB) muscles were recorded. The amount of visual feedback was altered by manipulation of visual gain (low and high). Beta-band corticomuscular coherence was computed between EEG over the sensorimotor cortex and EMG from the FDI muscle and between EEG and EMG from the APB muscle (EEG-FDI and EEG-APB coherences). Also, beta-band intermuscular coherence was computed between EMG signals from the FDI and APB muscles (EMG-EMG coherence). Task performance was quantified as standard deviation (SD) of force and mean force error (MFE). EEG-FDI coherence was larger at high than low visual gain in the elderly but not in the young subjects, whereas there was no effect of age or visual gain on EEG-APB coherence. EMG-EMG coherence was smaller at high than low visual gain in the young and elderly subjects. The MFE was smaller at high than low visual gain in the young and elderly subjects, but the SD of force was smaller at high than low visual gain only in the young subjects. These results suggest that the effect of aging on beta-band coherence depends on the amount of visual feedback and further that visual feedback modulates beta-band corticomuscular and intermuscular coherences differently.
We aimed to develop gait standards for gait parameters in school-aged Japanese children and assess age-related differences in gait patterns and parameters. Children aged 6-12 years (n = 424) were ...recruited from two elementary schools. An instrumented three-dimensional gait analysis system was used to record each child's gait kinematics, kinetics, and spatiotemporal parameters. Participants were subdivided into three age groups (Group A, 6-8 years; Group B, 9-10 years; and Group C, 11-12 years). LMS Chartmaker, version 2.54, was used to create a developmental chart for the gait pattern. The non-normalized step and stride lengths were significantly longer, and the cadence was lower in older children; however, the opposite outcome occurred when analyzing normalized data. Ankle moment differed significantly by age, and the maximum ankle moment was higher in older children than that in younger children. Furthermore, the hip and knee flexion angles during gait and the normalized spatiotemporal parameters of Japanese children aged 6-12 years differed by age and from those of children from other countries. The centile chart of the gait pattern is a useful tool for clinicians to assess developmental changes in the gait pattern and detect gait abnormalities in children.
In April 2020, the Japanese government declared a state of emergency due to the novel coronavirus disease (COVID-19). Schools were closed and a stay-at-home order was issued in April and May 2020. ...This before-and-after study aimed to measure the effects of these COVID-19-related restrictions on physical function among Japanese children. The study included children aged 6–7 years, enrolled before and after the emergency declaration. Their body fat percentage, single-leg standing time, Gait Deviation Index score, and history of falls were compared. There were 56 and 54 children in the before and after groups, respectively. Children in the after group had a higher body fat percentage (p = 0.037), shorter single-leg standing time (p = 0.003), and a larger number of falls per month (p < 0.001) than those in the before group. In the logistic regression analysis, children in the after group had a significantly shorter single-leg standing time (odds ratio (OR): 0.985, 95% confidence interval (CI): 0.972−0.997, p = 0.013), a greater number of falls per month (OR: 1.899, 95% CI: 1.123−3.210, p = 0.017), and a higher body fat percentage (OR: 1.111, 95% CI: 1.016−1.215, p = 0.020) than those in the before group. The COVID-19 emergency restrictions had a negative effect on children’s physical function, especially on balance.
Low-back pain is common among school-aged children. Decreased trunk flexibility in childhood influences low-back pain in adulthood. Previous studies examining the association between low-back pain ...and trunk flexibility in children are insufficient. Examining this association among elementary school children may help to better understand trunk flexibility in children with low-back pain and to modify the management of inflexibility. Therefore, this study aimed to identify the prevalence of low-back pain and its relationship with physical function among elementary school students. School-aged children aged 6-12 years were recruited in Japan between May 2018 and March 2023. Fingertip-to-floor distance, back muscle strength, pelvic tilt angle during gait, and the visual analog scale for low-back pain were measured. In addition, factors independently related to low-back pain were determined through logistic regression analysis. Low-back pain was reported in 9.6% of the 394 participants (boys, 191; girls, 203). All children with low-back pain presented with back pain when they moved; however, the pain was non-specific. Logistic regression analysis showed that the fingertip-to-floor distance was an independent risk factor for low-back pain (odds ratio, 0.921; p = 0.007). The odds ratios calculated in the logistic regression analysis confirmed that low-back pain frequency increased as the fingertip-to-floor distance decreased. The risk of low-back pain was associated with inflexibility, regardless of sex and muscle strength. These findings suggest that children with low-back pain must increase their trunk and lower extremity flexibility.
Cachexia is a multifactorial syndrome characterized by muscle loss that cannot be reversed by conventional nutritional support. To uncover the molecular basis underlying the onset of cancer cachectic ...muscle wasting and establish an effective intervention against muscle loss, we used a cancer cachectic mouse model and examined the effects of aerobic exercise. Aerobic exercise successfully suppressed muscle atrophy and activated adiponectin signaling. Next, a cellular model for cancer cachectic muscle atrophy using C2C12 myotubes was prepared by treating myotubes with a conditioned medium from a culture of colon-26 cancer cells. Treatment of the atrophic myotubes with recombinant adiponectin was protective against the thinning of cells through the increased production of p-mTOR and suppression of LC3-II. Altogether, these findings suggest that the activation of adiponectin signaling could be part of the molecular mechanisms by which aerobic exercise ameliorates cancer cachexia-induced muscle wasting.
Summary Background Trabectedin binds to the minor groove of DNA and blocks DNA repair machinery. Preclinical data have shown that trabectedin also modulates the transcription of the oncogenic fusion ...proteins of translocation-related sarcomas. We aimed to assess the efficacy and safety of trabectedin as second-line therapy or later for patients with advanced translocation-related sarcoma. Methods We did a multicentre randomised open-label study in Japan. Eligible patients had pathological diagnosis of translocation-related sarcoma, were aged 19 years or older, were unresponsive or intolerant to standard chemotherapy regimens, no more than four previous chemotherapy regimens, Eastern Cooperative Oncology Group performance status 0 or 1, adequate bone marrow reserve, renal and liver functions, and had measurable lesions. Patients were randomly assigned (1:1) by the minimisation method to receive either trabectedin (1·2 mg/m2 given via a central venous line over 24 h on day 1 of a 21 day treatment cycle) or best supportive care, which was adjusted centrally by pathological subtype. Investigators, patients, and the sponsor were unmasked to the treatment assignment. Progression-free survival and objective responses were assessed by a masked central radiology imaging review. Efficacy was assessed by masked central radiology imaging review. The primary endpoint was progression-free survival for the full analysis set population. Follow-up is ongoing for the patients under study treatment. The study is registered with Japan Pharmaceutical Information Center, number JapicCTI-121850. Findings Between July 11, 2012, and Jan 20, 2014, 76 patients were enrolled and allocated to receive either trabectedin (n=39) or best supportive care (n=37). After central review to confirm pathological subtypes, 73 patients (37 in the trabectedin group and 36 in the best supportive care group) were included in the primary efficacy analysis. Median progression-free survival of the trabectedin group was 5·6 months (95% CI 4·1–7·5) and the best supportive care group was 0·9 months (0·7–1·0). The hazard ratio (HR) for progression-free survival of trabectedin versus best supportive care was 0·07 (90% CI 0·03–0·14 and 95% CI 0·03–0·16) by a Cox proportional hazards model (p<0·0001). The most common drug-related adverse events for patients treated with trabectedin were nausea (32 89% of 36), decreased appetite (21 58%), decreased neutrophil count (30 83%), increased alanine aminotransferase (24 67%), and decreased white blood cell count (20 56%). Interpretation Trabectedin significantly reduced the risk of disease progression and death in patients with advanced translocation-related sarcoma after standard chemotherapy such as doxorubicin, and should be considered as a new therapeutic treatment option for this patient population. Funding Taiho Pharmaceutical Co., Ltd.
The objective of this study was to identify the MRI criteria that best differentiate malignant peripheral nerve sheath tumors from benign neurofibromas.
We retrospectively analyzed MR images obtained ...for 41 histologically diagnosed cases of malignant peripheral nerve sheath tumor and 20 cases of neurofibroma that had been treated at four tertiary institutions. Twenty of the patients with malignant peripheral nerve sheath tumors and 14 patients with neurofibromas developed the disease in association with neurofibromatosis 1. The MR images were evaluated with regard to tumor size, signal intensity, heterogeneity of T1- and T2-weighted MR images, enhancement pattern, definition of margins, presence of perilesional edemalike zone, and presence of intratumoral cystic lesions.
Significant differences between malignant peripheral nerve sheath tumors and neurofibromas were noted for the largest dimension of the mass, peripheral enhancement pattern, perilesional edemalike zone, and intratumoral cystic lesion. In cases associated with neurofibromatosis 1, heterogenicity on T1-weighted images was also significant in differentiating neurofibroma from malignant peripheral nerve sheath tumor. The presence of two or more of the four features suggestive of malignancy indicated malignant peripheral nerve sheath tumor with a sensitivity of 61% and a specificity of 90%.
The MR features described in this study are useful for distinguishing malignant peripheral nerve sheath tumors from neurofibromas. If a tumor has two or more of the four statistically significant features, it can be considered to be highly suspicious of malignancy and should be subjected to a biopsy for early diagnosis.
A live assay tool has been established to uncover the precise molecular mechanisms underlying complex cell fusion events in myoblasts. The novel cell-based assay, HiMy (HiBiT-based myoblast fusion), ...utilizes a recently developed split-luciferase technology. The assay successfully detected cell fusion in differentiating C2C12 myoblast cultures. This allowed us to measure mixing of the cytoplasm, which occurred several hours after the initiation of C2C12 differentiation. Unlike what was reported earlier, the fusion was detected a few hours after the initiation of differentiation. Thus, this assay is sensitive enough to monitor fusion events before they become detectable using conventional methods. Furthermore, a panel of laboratory compounds, including a variety of inhibitors of cellular enzymes or activities, were assayed using the HiMy assay. Lovastatin, a cholesterol biogenesis inhibitor, decreased HiMy activity by approximately 50%. In contrast, mevalonolactone, a precursor for cholesterol synthesis, increased fusion activity. These results confirmed the previous finding that the amount of cellular cholesterol positively correlates with the rate of myoblast fusion during myogenesis. These results indicate that the novel cell fusion assay is a quick, accurate, and robust method to monitor intercellular fusion events.
There is evidence that social relationships may modify cognitive decline in older people. We examined the prospective association between social support and cognitive function among ...community-dwelling older people. Japanese adults recruited at health checkups in suburban towns were surveyed at baseline and one-year follow-up. Cognitive function was assessed using the Montreal Cognitive Assessment, Japanese version (MoCA-J). Social support from coresiding family, non-coresiding family, and neighbors/friends was assessed using self-administered questionnaires. Multivariable linear regression analysis was conducted to examine the effects of social support on MoCA-J scores at follow-up. Data were analyzed from 121 older people (mean age (standard deviation): 73.86 (4.95) years). There was a positive association between social support exchanges with neighbors and friends and MoCA-J scores at follow-up after covariate adjustment (unstandardized β = 1.23,
= 0.006). Social support exchanges with coresiding family and non-coresiding family and relatives were not associated with MoCA-J scores at follow-up (coresiding family: Unstandardized β = 0.28,
= 0.813, non-coresiding family and relatives: Unstandardized β = 0.51,
= 0.238). The provision of emotional support to neighbors and friends had the largest effect on MoCA-J scores. Our findings suggest that social support exchanges with neighbors and friends are protective against cognitive decline.
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