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Abstract Objectives Synovial mesenchymal stem cells (MSCs) have high freeze–thaw tolerance, whereas human umbilical vein endothelial cells (HUVECs) have low freezing tolerance. The differences in cell type-specific freeze–thaw tolerance and the mechanisms involved are unclear. This study thus aimed to identify the biological and physical factors involved in the differences in freeze–thaw tolerance between MSCs and HUVECs. Materials and methods For biological analysis, MSC and HUVEC viability after freeze-thawing and alteration of gene expression in response to dimethyl sulfoxide (DMSO, a cryoprotectant) were quantitatively evaluated. For physical analysis, the cell membrane fluidity of MSCs and HUVECs before and after DMSO addition was assessed using a histogram for generalized polarization frequency. Results HUVECs showed lower live cell rates and higher gene expression alteration related to extracellular vesicles in response to DMSO than MSCs. Fluidity measurements revealed that the HUVEC membrane was highly fluidic and sensitive to DMSO compared to that of MSCs. Addition of CAY10566, an inhibitor of stearoyl-coA desaturase (SCD1) that produces highly fluidic desaturated fatty acids, decreased the fluidity of HUVECs and increased their tolerance to DMSO. The combination of CAY10566 and antioxidant glutathione (GSH) treatment improved HUVEC viability from 57 to 69%. Membrane fluidity alteration may thus contribute to pore-induced DMSO influx into the cytoplasm and reactive oxygen species production, leading to greater cytotoxicity in HUVECs, which have low antioxidant capacity. Conclusions Differences in freeze–thaw tolerance originate from differences in the cell membranes with respect to fluidity and antioxidant capacity. These findings provide a basis for analyzing cell biology and membrane-physics to establish appropriate long-term preservation methods aimed at promoting transplantation therapies.

An even 2-factor is one such that each cycle is of even length. A 4- regular graph G is 4-edge-colorable if and only if G has two edge-disjoint even 2- factors whose union contains all edges in G. It is known that the line graph of a cubic graph without 3-edge-coloring is not 4-edge-colorable. Hence, we are interested in whether those graphs have an even 2-factor. Bonisoli and Bonvicini proved that the line graph of a connected cubic graph G with an even number of edges has an even 2-factor, if G has a perfect matching [Even cycles and even 2-factors in the line graph of a simple graph, Electron. J. Combin. 24 (2017), P4.15]. In this paper, we extend this theorem to the line graph of a connected cubic graph G satisfying certain conditions.

Abstract Background Anaplastic lymphoma kinase (ALK)–tyrosine kinase inhibitors (TKIs) have been approved for the therapy of locally advanced non-small cell lung cancer (NSCLC) caused by ALK rearrangement. However, its treatment after failure of initial ALK–TKI therapy remains controversial. Case presentation A 47-year-old woman with a hemosputum was diagnosed with adenocarcinoma of the left lung (cT2bN3M0, stage IIIB). Gene mutation analysis indicated positive ALK translocation. Alectinib was selected as the first-line treatment. Although the treatment effect was determined as a partial response, the main tumor regrew. Alectinib was discontinued, and salvage surgery was performed without causing morbidity. The pathological diagnosis was pleomorphic carcinoma without lymph node metastasis (yp-T2bN0). After surgery, lorlatinib was administered as the second-line treatment for 8 months until the patient could not tolerate continuation. Computed tomography scan revealed no lung cancer recurrence 14 months after discontinuation. Conclusions Our experience with this case suggests that salvage surgery after alectinib treatment followed by lorlatinib therapy may be effective for initially unresectable ALK-positive NSCLC.

Background and Objectives: We analyzed the changes in obesity, glucose metabolism, and body composition over a 3-year period in Japanese patients with obesity following laparoscopic sleeve gastrectomy (LSG). Methods: Body weight, parameters related to diabetes such as glycated hemoglobin (HbA1c), and electrical impedance analysis were used to assess body composition in forty-eight Japanese patients with obesity before surgery and 6 months, 1 year, 2 years, and 3 years after LSG. Results: At 6 months, 1, 2, and 3 years post-LSG, there were significant reductions in body weight, body mass index, blood pressure, fasting plasma glucose, triglyceride, and HbA1c levels. Six months after LSG, fat mass (FM), muscle mass (MM), and %FM all showed a decrease compared to pre-treatment values (all p < 0.05). FM and %FM remained in a decreased state until 3 years had passed. In contrast, %MM increased at 6 months post-LSG and was maintained up to 3 years post-LSG (all p < 0.05). Furthermore, changes in FM and %FM were associated with changes in body weight and A1C. In contrast, change in %MM exhibited a negative correlation with body weight and A1C following LSG. Finally, multivariate regression analyses demonstrated that alterations in FM were independent factors affecting body weight in patients with obesity 3 years after LSG. Conclusions: We observed improvements in FM, fasting plasma glucose, and HbA1c levels over a 3-year period in Japanese patients after LSG. The reduction in FM and maintenance of %MM after LSG were suggested as possible links between the effects of LSG on obesity and diabetes over 3 years. [ABSTRACT FROM AUTHOR]

Background: Assessing the internal condition of swallowing‐related muscles and muscle strength and size is important because their deterioration may lead to dysphagia. However, there are few reports on stiffness of swallowing‐related muscles measured using shear‐wave elastography (SWE) and their qualitative characteristics. Objectives: We measured stiffness of swallowing‐related muscles using SWE to investigate the relationship between muscle stiffness and body composition as well as other relevant variables in healthy adults. Methods: Thirty healthy adults were included in this cross‐sectional study. We evaluated stiffness of the genioglossus muscle (GGM) and geniohyoid muscle (GHM) using SWE. Skeletal muscle mass index, body mass index (BMI), handgrip strength, tongue pressure, and cross‐sectional areas of the muscles were measured, and we determined their relationship with muscle stiffness. Results: For muscle stiffness, the mean value for the middle GGM was 7.08 ± 1.92 kPa, that for the posterior GGM was 9.31 ± 2.68 kPa, and that for the GHM was 8.84 ± 2.15 kPa. In multiple regression analysis, with stiffness of the posterior GGM as the dependent variable, BMI (β = −.473, p =.039) was a significant negative explanatory variable. However, with the GHM stiffness as the dependent variable, BMI (β =.419, p =.033) was a significant positive explanatory variable. Conclusion: Stiffness of the posterior GGM was positively correlated with BMI and that of the GHM was negatively correlated with BMI. Stiffness, as measured using SWE, has the potential to capture the intramuscular characteristics of swallowing‐related muscles, particularly the posterior GGM. [ABSTRACT FROM AUTHOR]

Background: Nontuberculous mycobacterial disease has emerged worldwide over the past 20 years. However, there are currently few reports on the established technique for constructing knockout mutants of nontuberculous mycobacteria. Therefore, gene recombination techniques for nontuberculous mycobacteria require further research. Results: We constructed vector pPR23LHR that harbors the ribosomal protein S12 gene (rpsL+) as a dominant negative selection marker and the hygromycin (Hyg) and lacZ cassettes as positive selection markers. We constructed knockout mutants of proteasomal genes, which we found to be required for hypoxic pellicle formation in Mycobacterium intracellulare by functional genomic analysis. The knockout mutants showed impaired hypoxic pellicle formation, consistent with previous data using epoxomicin, a proteasomal inhibitor. Conclusions: Our findings demonstrate that rpsL+ is an efficient dominant negative selection marker for gene recombination in nontuberculous mycobacteria. Our temperature‐sensitive rpsL+ method for the construction of knockout mutants will facilitate functional assays to validate the virulence factors of nontuberculous mycobacteria and the pathogenesis of nontuberculous mycobacterial disease. [ABSTRACT FROM AUTHOR]