The most important requirements of biomedical substitutes used in muscle tissue regeneration are appropriate topographical cues and bioactive components for the induction of myogenic differentiation/maturation. Here, we developed an electric field-assisted 3D cell-printing process to fabricate cell-laden fibers with a cell-alignment cue. Methods : We used gelatin methacryloyl (GelMA) laden with C2C12 cells. The cells in the GelMA fiber were exposed to electrical stimulation, which induced cell alignment. Various cellular activities, such as cell viability, cell guidance, and proliferation/myogenic differentiation of the microfibrous cells in GelMA, were investigated in response to parameters (applied electric fields, viscosity of the bioink, and encapsulated cell density). In addition, a cell-laden fibrous bundle mimicking the structure of the perimysium was designed using gelatin hydrogel in conjunction with a 4D bioprinting technique. Results : Cell-laden microfibers were fabricated using optimized process parameters (electric field intensity = 0.8 kV cm -1 , applying time = 12 s, and cell number = 15 × 10 6 cells mL -1 ). The cell alignment induced by the electric field promoted significantly greater myotube formation, formation of highly ordered myotubes, and enhanced maturation, compared to the normally printed cell-laden structure. The shape change mechanism that involved the swelling properties and folding abilities of gelatin was successfully evaluated, and we bundled the GelMA microfibers using a 4D-conceptualized gelatin film. Conclusion : The C2C12-laden GelMA structure demonstrated effective myotube formation/maturation in response to stimulation with an electric field. Based on these results, we propose that our cell-laden fibrous bundles can be employed as in vitro drug testing models for obtaining insights into the various myogenic responses.

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Aim/BackgroundThe prevalence of elderly pregnancy and maternal obesity is increasing worldwide. In old and obese women, metabolic derangement affecting fetal growth might be present earlier than the diagnosis of gestational diabetes mellitus (GDM) or even before pregnancy. We thus investigated whether GDM diagnosed at 24–28 weeks of gestation had already affected fetal abdominal growth and, if so, whether elderly pregnancy and/or maternal obesity aggravate fetal abdominal obesity.MethodsWe retrospectively reviewed the medical records of 7820 singleton pregnant women who had been universally screened using a 50-g glucose challenge test (GCT) at 24–28 weeks of gestation, and underwent a 3-h 100-g oral glucose tolerance test (OGTT) if GCT were ≥140mg/dl. GDM and normal glucose tolerance (NGT) were diagnosed using the Carpenter-Coustan criteria. Fetal abdominal obesity was investigated by assessing the fetal abdominal overgrowth ratios (FAORs) of the ultrasonographically estimated gestational age (GA) of abdominal circumference per actual GA by the last menstruation period, biparietal diameter or femur length, respectively. Fetal abdominal overgrowth was defined as FAOR ≥ 90th percentile. The subjects were divided into four study groups: group 1 (age < 35 years and pre-pregnancy body mass index [BMI] < 25 kg/m2), group 2 (age < 35 years and ≥ 25), group 3 (age ≥ 35 years and BMI < 25), and group 4 (age ≥ 35 years and ≥ 25).ResultsThe overall prevalence of GDM was 5.1%, with old and obese group 4 exhibiting the highest prevalence (22.4%). FAORs were significantly higher in the fetus of those with GDM than in the NGT subjects. But, in the subgroup analysis, only old and nonobese group 3 and old and obese group 4 with GDM exhibited significantly higher FAORs than the NGT subjects. Also, risk of fetal abdominal overgrowth was increased in group 3 and 4 subjects with GDM but not in young and nonobese group 1 GDM. The risk of fetal abdominal overgrowth significantly increased with maternal age >35 years, pre-pregnancy BMI >20kg/m2, and HbA1c >37.7 mmol/mol (5.6%). In multivariate analyses, maternal age and HbA1c were significantly associated with FAORs.ConclusionGDM diagnosed at 24–28 weeks of gestation already affected fetal abdominal obesity in older and/or obese women, but not in younger and nonobese women. Our data suggest that selective screening and appropriate intervention of GDM earlier than 24–28 weeks of gestation might be necessary for high-risk old and/or obese women.

BackgroundThe aim of this study was to investigate the prevalence of obesity in Korean men with Klinefelter syndrome (KS) and the associated risk factors for obesity and hyperglycemia.MethodsData were collected retrospectively from medical records from 11 university hospitals in Korea between 1994 and 2014. Subjects aged ≥18 years with newly diagnosed KS were enrolled. The following parameters were recorded at baseline before treatment: chief complaint, height, weight, fasting glucose level, lipid panel, blood pressure, testosterone, luteinizing hormone, follicle-stimulating hormone, karyotyping patterns, and history of hypertension, diabetes, and dyslipidemia.ResultsData were analyzed from 376 of 544 initially enrolled patients. The rate of the 47 XXY chromosomal pattern was 94.1%. The prevalence of obesity (body mass index ≥25 kg/m2) in Korean men with KS was 42.6%. The testosterone level was an independent risk factor for obesity and hyperglycemia.ConclusionObesity is common in Korean men with KS. Hypogonadism in patients with KS was associated with obesity and hyperglycemia.

[Purpose] This study aimed to investigate the effect of neuromuscular electrical stimulation (NMES) on lip strength and closure function of patients with dysphagia after stroke. [Subjects and Methods] Eight patients with dysphagia were recruited. NMES was applied to the orbicularis oris muscle. All the participants received NMES for 30 min/d, 5 d/wk, for 4 weeks. Lip strength was measured using the Iowa Oral Performance Instrument. To assess lip closure, the lip closure subitem of the videofluoroscopic dysphagia scale was used. [Results] Lip strength showed significant improvement and lip closure function showed a significant decrease. [Conclusion] This study demonstrates that NMES is useful for improving lip strength and closure function.

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Spondin-2 (SPON2) is involved in cancer progression and metastasis of many tumors; however, its role and underlying mechanism in gastric cancer are still obscure. In this study, we investigated the role of SPON2 and related signaling pathway in gastric cancer progression and metastasis. SPON2 expression levels were found to be upregulated in gastric cancer cell lines and patient tissues compared to normal gastric epithelial cells and normal controls. Furthermore, SPON2 silencing was observed to decrease cell proliferation and motility and reduce tumor growth in xenograft mice. Conversely, SPON2 overexpression was found to increase cell proliferation and motility. Subsequently, we focused on regulatory mechanism of SPON2 in gastric cancer. cDNA microarray and in vitro study showed that Notch signaling is significantly correlated to SPON2 expression. Therefore, we confirmed how Notch signaling pathway regulate SPON2 expression using Notch signaling-related transcription factor interaction and reporter gene assay. Additionally, activation of Notch signaling was observed to increase cell proliferation, migration, and invasion through SPON2 expression. Our study demonstrated that Notch signaling-mediated SPON2 upregulation is associated with aggressive progression of gastric cancer. In conclusion, we suggest upregulated SPON2 via Notch signaling as a potential target gene to inhibit gastric cancer progression.

Li-ion solid-state electrolytes (SSEs) have great potential, but their commercialization is limited due to interfacial contact stability issues and the formation and growth of dendrites. In this study, a machine learning regression algorithm was implemented to screen for mechanically superior SSEs among 17,619 candidates. Elasticity information (14,238 structures) was imported from an available database, and their machine learning descriptors were constructed using physiochemical and structural properties. A surrogate model for predicting the shear and bulk moduli exhibited R 2 values of 0.819 and 0.863, respectively. The constructed model was applied to predict the elastic properties of potential SSEs, and first-principles calculations were conducted for validation. Furthermore, the application of an active learning process, which reduced the prediction uncertainty, was clearly demonstrated to improve the R 2 score from approximately 0.6–0.8 by adding only 32–63% of new data sets depending on the type of modulus. We believe that the current model and additional data sets can accelerate the process of finding optimal SSEs to satisfy the mechanical conditions being sought.