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Abstract Aging and obesity pose significant threats to public health and are major contributors to muscle atrophy. The trends in muscle fiber types under these conditions and the transcriptional differences between different muscle fiber types remain unclear. Here, we demonstrate distinct responses of fast/glycolytic fibers and slow/oxidative fibers to aging and obesity. We found that in muscles dominated by oxidative fibers, the proportion of oxidative fibers remains unchanged during aging and obesity. However, in muscles dominated by glycolytic fibers, despite the low content of oxidative fibers, a significant decrease in proportion of oxidative fibers was observed. Consistently, our study uncovered that during aging and obesity, fast/glycolytic fibers specifically increased the expression of genes associated with muscle atrophy and inflammation, including Dkk3, Ccl8, Cxcl10, Cxcl13, Fbxo32, Depp1, and Chac1, while slow/oxidative fibers exhibit elevated expression of antioxidant protein Nqo-1 and downregulation of Tfrc. Additionally, we noted substantial differences in the expression of calcium-related signaling pathways between fast/glycolytic fibers and slow/oxidative fibers in response to aging and obesity. Treatment with a calcium channel inhibitor thapsigargin significantly increased the abundance of oxidative fibers. Our study provides additional evidence to support the transcriptomic differences in muscle fiber types under pathophysiological conditions, thereby establishing a theoretical basis for modulating muscle fiber types in disease treatment.

BackgroundMalnutrition and sarcopenia are common in elderly gastric cancer patients, which are also interrelated and affect each other. We aimed to determine the characteristics of coexistence of malnutrition and sarcopenia in the elderly gastric cancer patients and investigate the predictive roles of malnutrition and sarcopenia on clinical outcomes.MethodsBetween 2014 and 2019, a total of 742 elderly gastric cancer patients were enrolled. Malnutrition and sarcopenia were diagnosed according to the most recent diagnostic criteria. Patients were divided into four groups according to presence of these two symptoms. Clinical characteristics, short- and long-term outcomes were compared among four groups. The independent risk factors for complications and survival were evaluated using univariate and multivariate analyses.ResultsOf all patients, 34.8% were diagnosed with malnutrition and 34.0% were diagnosed with sarcopenia. Patients with both malnutrition and sarcopenia had the highest rate of total (P < 0.001), surgical (P = 0.003), and medical complications (P = 0.025), and the highest postoperative hospital stays (P < 0.001) and hospitalization costs (P < 0.001). They also had the worst overall survival (P < 0.0001) and disease-free survival (P < 0.0001). Sarcopenia and Charlson Comorbidity Index (≥2) were independent risk factors for total complications. Hypoalbuminemia and malnutrition were non-tumor-related independent risk factors for overall survival and disease-free survival.ConclusionsMalnutrition and sarcopenia had superimposed negative effects on elderly gastric cancer patients. Preoperative geriatric evaluation including screening for malnutrition and sarcopenia are recommended for all elderly gastric cancer patients for accurate treatment strategy.

AIM: To investigate the effect of blocking short wave visible light(400-500nm)on tear film stability in healthy people. METHODS: In this prospective intervention experiment, 26 college students were selected, including 12 males and 14 females, aged 22.1±1.4 years, from February to March 2020. At the same time of two adjacent days, the subjects watched the video for 1h under the same environmental conditions. For the first time, there was no short wave visible light blocking, and for the second time, they wore short wave visible light blocking myopia or flat glasses. The subjects were examined the radius of curvature of lacrimal River curved surface, tear osmolality, tear film rupture time, corneal fluorescein sodium staining score, the basic state before watching the video and after watching the video respectively. And the questionnaire of visual perception was completed at the end of the experiment. RESULTS: There were significant differences in the radius of curvature of lacrimal River curved surface, tear osmolality, tear film rupture time, corneal fluorescein sodium staining score between the basic state and the short wave visible unstopped state(t=4.50, 5.72, 4.437, 3.245, P0.05). There was also significant difference between the short wave visible light blocking and the short wave visible light unblocking(t=2.825, 3.771, 2.610, 3.028, P< 0.05). The results of the questionnaire showed that: eighteen subjects(69%)said that wearing the short wave visible light blocking glasses or without wearing short wave visible light blocking glasses had slight eye dryness, pain, foreign body sensation, visual fatigue and other discomfort after watching the video. Sixteen subjects(62%)said that they were more comfortable after blocking the short wave visible light. Twenty-four subjects(92%)said that they were willing to block the short wave visible light. CONCLUSION: The stability of tear film could be reduced by watching the display screen for a short time. Blocking the short wave visible light could protect the stability of tear film of the ocular surface.

Background and Aims: Sarcopenia is negatively associated with clinical outcomes. However, the definitions of sarcopenia are inconsistent across international consensuses. Thus, the purpose of this study is to compare the impact of the basic definition components of sarcopenia and their combinations in post-operative complications and overall survival, aiming to find the best sarcopenia definition to stratify the prognosis in an Asian population.Methods: A total of 1,307 patients who underwent curative surgery for gastric cancer from July 2014 to May 2019 were prospectively included. The basic sarcopenia components were measured pre-operatively, including low skeletal muscle mass index (LSMI), low skeletal muscle radiodensity (LSMD), low handgrip strength (LHGS), and low gait speed (LGS). Among them, LSMI and LSMD were measured using a CT post-processing software, LHGS was measured using an electronic hand dynamometer, and LGS was represented by a 6-m walk speed.Results: For the single basic component, the muscle function parameters (LHGS or LGS) but not the muscle composition parameters (LSMI or LSMD) showed associations with post-operative complications and mortality. For the combination of the basic combinations, all statistically significant combinations included at least one muscle function parameter. The combination of muscle composition (LSMI or LSMD) and muscle function (LHGS or LGS) had a significantly higher area under the curve in the prediction of post-operative complications compared with the combinations of two muscle function parameters (LSMI plus LSMD) or two muscle composition parameters (LHGS plus LGS).Conclusions: Compared with muscle composition parameters (LSMI and LSMD), muscle function parameters (LHGS and LGS) are better predictors of post-operative complications and overall survival, which should be considered as the principal determinant in the sarcopenia definition. The definition of sarcopenia consists of muscle function (LHGS or LGS) and muscle composition (LSMI or LSMD) separately, which is better than the combination of the two muscle function parameters (LHGS plus LGS) or two muscle composition parameters (LSMI plus LSMD).