Frontiers in Physiology最新文献

Introduction: The juvenile hormone (JH) and 20-hydroxyecdysone (20E) are the central regulating hormones of insect development. The timing of their secretion usually leads to developmental transitions.

Methods: The developmental transitions were evaluated via the starvation treatment and the expressions of two key metamorphosis inducing factor in Spodoptera frugiperda. Then, the main endocrine organs, including the brain-corpora cardiacum-corpora allatum and prothoracic gland, were sampled from L4-24 h and L6-24 h larvae for the RNA-seq analysis. Additionally, the critical rate-limiting enzyme of 20E synthesis, shadow, was knocked down to mimic the downregulation of 20E synthesis in the late larval instar.

Results: The critical weight (CW), when JH titer declines for metamorphosis, was determined be approximately L6-24 h in S. frugiperda. However, the expression of the pupal specifier Broad-Complex and the potential "metamorphosis initiation factor" Myoglianin showed a stepwise increase between L4-24 h and L6-24 h, suggesting that the developmental transitions may occur earlier. The RNA-seq analysis revealed that both 20E and JH synthesis enzymes were downregulated at the CW. In addition, strong tendencies in the expression pattern were detected among the lists of transcripts. Further knockdown of shadow induced larval development arrest and subsequent mortality, indicating that disrupting 20E synthesis before the CW is lethal. Besides, JH synthesis enzyme was down-regulated.

Conclusion: The downregulation of 20E synthesis enzymes at the CW may represent a carefully regulated event, suggesting a deceleration of larval growth and the initiation of some underlying physiological changes to set the stage for metamorphosis.

Introduction: Automatic segmentation of the left atrium (LA) constitutes a crucial pre-processing step in evaluating heart structure and function during clinical interventions, such as image-guided radiofrequency ablation of atrial fibrillation. Despite prior research on LA segmentation, the low contrast in medical images exacerbates the challenge of distinguishing various tissues, rendering accurate boundary delineation of the target area formidable. Moreover, class imbalance due to the small target size further complicates segmentation.

Methods: This study aims to devise an architecture that augments edge information for LA segmentation from late gadolinium enhancement magnetic resonance imaging. To intensify edge information within image features, this study introduces an Edge Information Enhancement Module (EIEM) to the foundational network. The design of EIEM is grounded in exploring edge details within target region features learned from images. Additionally, it incorporates a Spatially Weighted Cross-Entropy loss function tailored for EIEM, introducing constraints on different regions based on the importance of pixels to edge segmentation, while also mitigating class imbalance through weighted treatment of positive and negative samples.

Results: The proposed method is validated on the 2018 Atrial Segmentation Challenge dataset. Compared with other state-of-the-art algorithms, the proposed algorithm demonstrated a significant improvement with an average symmetric surface distance of 0.684 mm and achieved a commendable Dice coefficient of 0.924, implicating the effectiveness of enhancing edge information.

Discussion: The method offers a practical framework for precise LA localization and segmentation, particularly strengthening the algorithm's effectiveness in improving segmentation outcomes for irregular protrusions and discrete multiple targets. Additionally, the generalizability of our model was evaluated on the heart dataset from the Medical Segmentation Decathlon (MSD) challenge, confirming its robustness across different clinical scenarios involving LA segmentation.

Objective: Glucose metabolism is the main way in which cells obtain energy during exercise and plays an important role in exercise. The purpose of this study was to explore the changes in the expression of glucose metabolism-related proteins in urine after running, and finally applied to the monitoring of running training.

Methods: Urine samples were collected before and after running, and urine proteomics information was collected to explore the expression of proteins in the urine using LC-MS/MS in DDA mode and DIA mode. Receiver operating characteristic (ROC) curve was drawn to evaluate the value of target proteins in monitoring running training.

Results: A total of 140 proteins were identified using LC-MS/MS in DDA mode, of which 49 urine proteins showed increased expression after running. KEGG analysis revealed that glucose metabolism-related proteins are mainly concentrated in glycolysis. There were six glycolysis-related proteins, among which urine proteins PKM, TPI1, ENO1 and LDHB were significantly increased after running (P < 0.05). This changes in urine proteins PKM, TPI1, ENO1 and LDHB were further verified by the results of LC-MS/MS in DIA mode. The concentrations of the urine proteins TPI1, ENO1 and LDHB showed a significant linear relationship with PKM. ROC curve analysis showed that PKM, TPI1, ENO1 and LDHB proteins in urine had good monitoring values for running training.

Conclusion: The expression of glycolysis-related proteins PKM, TPI1, ENO1 and LDHB in urine was significantly increased after running, which may be applied to the monitoring of running training.

Duchenne muscular dystrophy (DMD) is caused by mutations in the gene encoding dystrophin, a subsarcolemmal protein whose absence results in increased susceptibility of the muscle fiber membrane to contraction-induced injury. This results in increased calcium influx, oxidative stress, and mitochondrial dysfunction, leading to chronic inflammation, myofiber degeneration, and reduced muscle regenerative capacity. Fast glycolytic muscle fibers have been shown to be more vulnerable to mechanical stress than slow oxidative fibers in both DMD patients and DMD mouse models. Therefore, remodeling skeletal muscle toward a slower, more oxidative phenotype may represent a relevant therapeutic approach to protect dystrophic muscles from deterioration and improve the effectiveness of gene and cell-based therapies. The resistance of slow, oxidative myofibers to DMD pathology is attributed, in part, to their higher expression of Utrophin; there are, however, other characteristics of slow, oxidative fibers that might contribute to their enhanced resistance to injury, including reduced contractile speed, resistance to fatigue, increased capillary density, higher mitochondrial activity, decreased cellular energy requirements. This review focuses on signaling pathways and regulatory factors whose genetic or pharmacologic modulation has been shown to ameliorate the dystrophic pathology in preclinical models of DMD while promoting skeletal muscle fiber transition towards a slower more oxidative phenotype.

Introduction: Fibromyalgia (FM) and chronic fatigue syndrome (CFS) are complex central sensitization syndromes that represent an important public health problem. Low cardiorespiratory fitness and muscle function with habitual intolerance to efforts are common characteristics of FM and CFS. This study aimed to examine the effect of a brief multicomponent intervention based on physical activity (PA), nutrition, and chronobiology on movement behaviors (PA, sedentary and sleep time), muscle strength, and cardiorespiratory capacity.

Methods: randomized controlled trial was conducted in primary healthcare in Catalonia. A total of 143 individuals with FM or FM and CFS concomitantly (age 50.8, SD 8.1; 94.4% women) were randomly allocated to the intervention (IG, n = 69) or control (CG, n = 74) groups. The IG participated in a brief multicomponent (PA, nutrition, and chronobiology) group-based intervention (4 sessions, 3 h/session) while the CG received usual primary care practice. Primary outcome measure was PA measured by the REGICOR-Short Physical Activity Questionnaire. Secondary outcomes were sedentary (International Physical Activity Questionnaire) and sleep time (Pittsburgh Sleep Quality Index), upper- and lower-body muscle strength (handgrip and sit-to-stand test, respectively), and aerobic capacity (6-min walk test). Data were collected at baseline and 3 months post-intervention.

Results: The IG showed positive differences at 3-month follow-up, with highly appreciably PA levels, less sedentary time, and significantly improved sleep time. Significant between-group differences were also observed at 3 months, with better health values in the IG: PA and sleep time (370.3 ± 307.0 vs. 195.9 ± 289.1 min/week and 6.1 ± 1.6 vs. 5.5 ± 1.8 h/night, respectively) and less sedentary time (266.2 ± 153.3 vs. 209.4 ± 199.9 min/day). The IG also showed higher upper limb strength and significant lower-body strength both between and within groups, as well as significantly improved cardiorespiratory capacity.

Conclusion: The Synchronize + multicomponent program implemented at primary healthcare has shown short-term effectiveness in improving 24-h movement behaviors and health outcomes in individuals with FM, with or without CFS. This intervention may be a first step in educating and motivating people with FM and CFS to adopt an active lifestyle, leading to improved health. Long-term follow-up will determine whether the changes are maintained over time and their impact on quality of life and healthcare costs.

Background: The low-pressure, hypoxic environment characteristic of high-altitude regions significantly affects the cardiovascular and autonomic nervous system functions of individuals, consequently impairing their sleep quality. Heart rate variability, a non-invasive indicator of autonomic nervous system activity and balance within the cardiovascular system, has not been thoroughly investigated in terms of its patterns during acclimatization and de-acclimatization phases for individuals traveling to and residing in high-altitude areas and its relationship with sleep stability.

Methods: Data was collected from 22 medical staff members who traveled from Chengdu to Yecheng, with measurements taken before leaving Chengdu, 1 week in Yecheng, 3 months in Yecheng, and 1 week after returning to Chengdu. The study analyzed changes in heart rate variability during acclimatization and de-acclimatization at 1,400 m above sea level. It also examined arrhythmia and sleep disorders based on circadian groups.

Results: 1. Following 1 week of acclimatization to the sub-plateau environment of Yecheng, significant decreases were observed in SDANN, SDNN and SD2 indices compared to departure from Chengdu (P < 0.05). After 3 months of sub-plateau acclimatization, these indices significantly increased (P < 0.05). Upon returning to Chengdu and undergoing de-acclimatization for 1 week, these indices further significantly increased (P < 0.05). 2. During the period of sub-plateau acclimatization and de-acclimatization, significant changes were noted in average heart rate and minimum heart rate (P < 0.05), with the average heart rate showing a continuous decrease and the minimum heart rate exhibiting an initial increase followed by a decrease. No significant changes were observed in maximum heart rate or the incidence of arrhythmias (P > 0.05). 3. When stratified by day and night, the trends for SDANN, RMSSD, and TP were consistent with the overall trend at night (P < 0.05), but opposite during the day (P < 0.05). 4. During the sub-plateau acclimatization period, stable sleep duration was significantly reduced, and increased markedly after de-acclimatization, although it did not return to pre-acclimatization levels (P < 0.05).

Conclusion: Acclimatization to the sub-plateau environment of Yecheng affects the autonomic nervous system, heart rate, and sleep in healthy adults. De-acclimatization can ameliorate these effects. Furthermore, the impact of sub-plateau acclimatization on the autonomic nervous system exhibits a distinct circadian rhythmicity.

Purpose: Glomerular filtration rate (GFR) measured by dynamic renal scintigraphy (Gates method) is used in this study as the standard to investigate the applicability of two creatinine (Cr)-based GFR estimation equations in Chinese patients of different genders, age groups, and GFR stages diagnosed with neurogenic bladder (NB).

Methods: GFR values were measured using ^99mTc-DTPA renal dynamic imaging, the new serum creatinine (Cr)-based chronic kidney disease epidemiology collaborative group (CKD-EPI) equation, and the equation for the estimated GFR of CKD patients in China, which were designated as sGFR, EPI-GFR, and cGFR, respectively. Pearson's correlation and linear regression were used to compare the differences, absolute differences, precision, and accuracies of the results of the two equations with sGFR to determine the formula offering better performance for the assessment of patients with NB.

Results: Measurements from a total of 99 patients with NB were used in the final analysis. Both cGFR and EPI-GFR were moderately correlated with sGFR in both men and women. The overall staging accuracies of EPI-GFR and sGFR were significantly higher than that of cGFR. Among the patients staged, only those with GFRs in the range of 60-89 mL/min/1.73 m² had moderate correlations between cGFR, EPI-GFR, and sGFR, while the remaining patients had low correlations.

Conclusion: Researchers found that the equation developed for Chinese CKD patients performed well for patients with NB aged 20-25 years, while the race-neutral CKD-EPI equation performed better in NB patients aged 26-35 years.