BACKGROUND:Sarcopenia is an age-related condition characterized by the loss of skeletal muscle mass,strength,and/or physical function.Currently,effective treatments for sarcopenia remain limited.A new therapeutic approach to improve symptoms and prognosis of sarcopenia patients clinically was important.OBJECTIVE:To explore the effects of canine adipose-derived mesenchymal stem cells and their exosomes on a dexamethasone-induced sarcopenia in mice.METHODS:Mesenchymal stem cells were isolated and cultured from canine adipose tissue,and identified and functionally evaluated through flow cytometry and differentiation assays for osteogenesis,adipogenesis,and chondrogenesis.Subsequently,exosomes from adipose-derived mesenchymal stem cells were extracted and characterized using transmission electron microscopy,western blot assay,and nanocoulter tracking analysis.In vitro,the effects of canine adipose-derived mesenchymal stem cells and their exosomes on myotube growth and the expression of muscle atrophy-related genes were investigated using dexamethasone-induced C2C12 myotube atrophy and aging C2C12 models.In vivo,a dexamethasone-induced mouse sarcopenia model was established and received intraperitoneal or intravenous injection of canine adipose-derived mesenchymal stem cells.Therapeutic efficacy was assessed through mouse rotarod performance,histopathological analysis,and muscle atrophy-related genes testing.RESULTS AND CONCLUSION:(1)The isolated canine adipose-derived mesenchymal stem cells highly expressed CD73,CD90,and CD105,and lowly expressed MHC-Ⅱ,CD14,CD19,CD34,and CD45,and successfully differentiated into osteoblasts,adipocytes,and chondrocytes in vitro.(2)The adipose-derived mesenchymal stem cells-derived exosomes met the identification criteria in terms of particle size,electron microscopy morphology,and positive expression of specific markers.(3)Compared to the dexamethasone-induced C2C12 atrophy group,treatment with adipose-derived mesenchymal stem cells and their exosomes promoted the recovery and growth of myotubes,inhibited the expression of muscle atrophy-related genes MuRF1 and Atrogin-1.(4)Compared to the aging C2C12 group,adipose-derived mesenchymal stem cells and their exosomes significantly enhanced the recovery and growth of aged muscle tubes in aging cells.(5)Compared to the control group,the rotarod time in dexamethasone-induced sarcopenia model mice was significantly decreased(P＜0.01).After 7 days(P＜0.01,P＜0.01)and 10 days(P＜0.01,P＜0.05)of adipose-derived mesenchymal stem cells treatment via intraperitoneal and intravenous injection,rotarod time was significantly increased,respectively.After 14 days,all treatment groups showed longer rotarod times than the model group,although with no significant differences between them.(6)Compared to the control group,the cross-sectional area of anterior tibial muscle in the model group was significantly reduced(P＜0.01),and it was significantly increased after intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells(P＜0.05,P＜0.01).(7)Compared to the model group,intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells significantly inhibited the mRNA expression of MuRF1 and Atrogin-1 genes(P＜0.01,P＜0.01,P＜0.01,P＜0.01).The results indicated that adipose-derived mesenchymal stem cells and their exosomes promoted recovery and growth of atrophic myotube cells by inhibiting the expression of muscle atrophy-related genes,and both intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells provided good therapeutic effects on sarcopenia in mice.

BACKGROUND:Sarcopenia is an age-related condition characterized by the loss of skeletal muscle mass,strength,and/or physical function.Currently,effective treatments for sarcopenia remain limited.A new therapeutic approach to improve symptoms and prognosis of sarcopenia patients clinically was important.OBJECTIVE:To explore the effects of canine adipose-derived mesenchymal stem cells and their exosomes on a dexamethasone-induced sarcopenia in mice.METHODS:Mesenchymal stem cells were isolated and cultured from canine adipose tissue,and identified and functionally evaluated through flow cytometry and differentiation assays for osteogenesis,adipogenesis,and chondrogenesis.Subsequently,exosomes from adipose-derived mesenchymal stem cells were extracted and characterized using transmission electron microscopy,western blot assay,and nanocoulter tracking analysis.In vitro,the effects of canine adipose-derived mesenchymal stem cells and their exosomes on myotube growth and the expression of muscle atrophy-related genes were investigated using dexamethasone-induced C2C12 myotube atrophy and aging C2C12 models.In vivo,a dexamethasone-induced mouse sarcopenia model was established and received intraperitoneal or intravenous injection of canine adipose-derived mesenchymal stem cells.Therapeutic efficacy was assessed through mouse rotarod performance,histopathological analysis,and muscle atrophy-related genes testing.RESULTS AND CONCLUSION:(1)The isolated canine adipose-derived mesenchymal stem cells highly expressed CD73,CD90,and CD105,and lowly expressed MHC-Ⅱ,CD14,CD19,CD34,and CD45,and successfully differentiated into osteoblasts,adipocytes,and chondrocytes in vitro.(2)The adipose-derived mesenchymal stem cells-derived exosomes met the identification criteria in terms of particle size,electron microscopy morphology,and positive expression of specific markers.(3)Compared to the dexamethasone-induced C2C12 atrophy group,treatment with adipose-derived mesenchymal stem cells and their exosomes promoted the recovery and growth of myotubes,inhibited the expression of muscle atrophy-related genes MuRF1 and Atrogin-1.(4)Compared to the aging C2C12 group,adipose-derived mesenchymal stem cells and their exosomes significantly enhanced the recovery and growth of aged muscle tubes in aging cells.(5)Compared to the control group,the rotarod time in dexamethasone-induced sarcopenia model mice was significantly decreased(P＜0.01).After 7 days(P＜0.01,P＜0.01)and 10 days(P＜0.01,P＜0.05)of adipose-derived mesenchymal stem cells treatment via intraperitoneal and intravenous injection,rotarod time was significantly increased,respectively.After 14 days,all treatment groups showed longer rotarod times than the model group,although with no significant differences between them.(6)Compared to the control group,the cross-sectional area of anterior tibial muscle in the model group was significantly reduced(P＜0.01),and it was significantly increased after intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells(P＜0.05,P＜0.01).(7)Compared to the model group,intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells significantly inhibited the mRNA expression of MuRF1 and Atrogin-1 genes(P＜0.01,P＜0.01,P＜0.01,P＜0.01).The results indicated that adipose-derived mesenchymal stem cells and their exosomes promoted recovery and growth of atrophic myotube cells by inhibiting the expression of muscle atrophy-related genes,and both intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells provided good therapeutic effects on sarcopenia in mice.

Objective To investigate the exposure-response relationships and lag effects between air pollutants (PM_2.5, PM₁₀, O₃, and NO₂) and mortality in Jiading District, Shanghai, and to provide a scientific basis for the formulation of environmental health policies. Methods Using an individual-level time-stratified case-crossover design, conditional logistic regression models in conjunction with a distributed lag nonlinear model (DLNM) were employed to analyze the exposure-response relationship and temporal lag patterns of ambient air pollution on resident mortality in Jiading District (1994–2024). Results A total of 59 048 death cases were collected, including 18,701 deaths from cardiovascular diseases and 11 731 deaths from respiratory diseases. PM_2.5 and NO₂ had a significant impact on all-cause mortality, cardiovascular disease mortality, and respiratory disease mortality, with the most significant effects observed within a lag of 0–3 days. PM₁₀ also had some impact on these three types of mortality, but its effect was generally weaker than that of PM_2.5 and NO₂. The exposure-response curves showed that the risk of death increased rapidly with increasing concentrations of PM_2.5 and PM₁₀, while the effect of NO₂ plateaued at higher levels. No significant differences were found across age or gender subgroups. Conclusion Short-term exposure to PM_2.5, PM₁₀, and NO₂ significantly increases all-cause mortality risk in Jiading District, with effects persisting up to 7 days, highlighting the need for enhanced air pollution control measures, particularly targeting fine particulate matter.

Nanoparticle delivery systems have good application prospects in the field of precision therapy, but the preparation process of nanomaterial has problems such as short in vivo circulation time, easy recognition, and clearance by the immune system in the body. In recent years, biomimetic nanoparticle delivery systems mediated by natural cell membranes have become a research hotspot to address these issues. The natural membrane biomimetic nanoparticle delivery system cleverly integrates the advantages of natural biofilm "autologous" and "artificial" functional carriers by using endogenous cell membranes to modify the surface of nanocarriers, endowing them with characteristics such as tumor targeting, low immunogenicity, and long blood circulation. Currently, biomimetic nanoparticle delivery systems have been used in the treatment of malignant tumors, cardiovascular diseases, bacterial infections, and other diseases. This paper analyzes the development status and current research hotspots of natural cell membrane camouflaged biomimetic nanoparticle delivery systems mainly reviews the latest research progress of red blood cell membrane camouflaged biomimetic nanoparticle delivery systems in the field of disease treatment in recent years. It focuses on exploring the advantages, future development prospects, and limitations of biomimetic nanoparticle delivery systems based on red blood cell membrane camouflage in improving drug delivery, to provide a reference for the in-depth research and development of this system.

Objective: To assess the effect of transarterial embolization (TAE) for adhesive capsulitis (AC) by evaluating clinical outcomes and changes in inflammation using magnetic resonance imaging (MRI). Materials and Methods: Patients who had undergone TAE between August 2020 and August 2023 for AC refractory to conservative treatments without any invasive procedures for more than 3 months, and had undergone baseline and 3-month post-AC follow-up contrast-enhanced MRI evaluations, were included. A suspension mixture of 500 mg imipenem/cilastatin in 10 mL of iodinated contrast agent was used for TAE. MRI results were analyzed to assess periarticular capsule/ligament inflammation. Clinical assessments included pain scores using the numeric rating scale (NRS) and functional scores using the quick disabilities of the arm, shoulder, and hand (Quick DASH) questionnaire. Results: Twenty-five patients (female:male, 14:11; age, 54.9 ± 7.1 years) were included. Significant reductions in average NRS pain scores as well as improvements in Quick DASH scores and range of motion, including anterior flexion and abduction, were observed at 1, 3, and 6 months after TAE (all P < 0.001). MRI analyses revealed that TAE significantly decreased the grades of axillary recess capsule enhancement, rotator interval (RI) capsule T2 signal intensity, and RI capsule enhancement (all P ≤ 0.004). Conclusion TAE may be an effective and safe therapeutic approach for AC refractory to conservative treatments, alleviating pain and supporting functional recovery. The observed MRI findings suggest that the effectiveness of TAE for AC may be attributed to the reduction of inflammation and the elimination of angiogenesis.

Objective: To assess the effect of transarterial embolization (TAE) for adhesive capsulitis (AC) by evaluating clinical outcomes and changes in inflammation using magnetic resonance imaging (MRI). Materials and Methods: Patients who had undergone TAE between August 2020 and August 2023 for AC refractory to conservative treatments without any invasive procedures for more than 3 months, and had undergone baseline and 3-month post-AC follow-up contrast-enhanced MRI evaluations, were included. A suspension mixture of 500 mg imipenem/cilastatin in 10 mL of iodinated contrast agent was used for TAE. MRI results were analyzed to assess periarticular capsule/ligament inflammation. Clinical assessments included pain scores using the numeric rating scale (NRS) and functional scores using the quick disabilities of the arm, shoulder, and hand (Quick DASH) questionnaire. Results: Twenty-five patients (female:male, 14:11; age, 54.9 ± 7.1 years) were included. Significant reductions in average NRS pain scores as well as improvements in Quick DASH scores and range of motion, including anterior flexion and abduction, were observed at 1, 3, and 6 months after TAE (all P < 0.001). MRI analyses revealed that TAE significantly decreased the grades of axillary recess capsule enhancement, rotator interval (RI) capsule T2 signal intensity, and RI capsule enhancement (all P ≤ 0.004). Conclusion TAE may be an effective and safe therapeutic approach for AC refractory to conservative treatments, alleviating pain and supporting functional recovery. The observed MRI findings suggest that the effectiveness of TAE for AC may be attributed to the reduction of inflammation and the elimination of angiogenesis.

Objective: To assess the effect of transarterial embolization (TAE) for adhesive capsulitis (AC) by evaluating clinical outcomes and changes in inflammation using magnetic resonance imaging (MRI). Materials and Methods: Patients who had undergone TAE between August 2020 and August 2023 for AC refractory to conservative treatments without any invasive procedures for more than 3 months, and had undergone baseline and 3-month post-AC follow-up contrast-enhanced MRI evaluations, were included. A suspension mixture of 500 mg imipenem/cilastatin in 10 mL of iodinated contrast agent was used for TAE. MRI results were analyzed to assess periarticular capsule/ligament inflammation. Clinical assessments included pain scores using the numeric rating scale (NRS) and functional scores using the quick disabilities of the arm, shoulder, and hand (Quick DASH) questionnaire. Results: Twenty-five patients (female:male, 14:11; age, 54.9 ± 7.1 years) were included. Significant reductions in average NRS pain scores as well as improvements in Quick DASH scores and range of motion, including anterior flexion and abduction, were observed at 1, 3, and 6 months after TAE (all P < 0.001). MRI analyses revealed that TAE significantly decreased the grades of axillary recess capsule enhancement, rotator interval (RI) capsule T2 signal intensity, and RI capsule enhancement (all P ≤ 0.004). Conclusion TAE may be an effective and safe therapeutic approach for AC refractory to conservative treatments, alleviating pain and supporting functional recovery. The observed MRI findings suggest that the effectiveness of TAE for AC may be attributed to the reduction of inflammation and the elimination of angiogenesis.

The objective assessment of hearing loss is one of the critical components in forensic clini-cal research.Auditory brainstem response(ABR)is an important method for objectively assessing hearing levels.It is divided into various types based on different stimulus signals,each with its own characteris-tics and applications.Among them,narrow-band Chirp ABR,due to its frequency specificity,fulfills the basic requirements for objective assessment of forensic audiology,promising to be an important method of objective hearing assessment in forensic medicine.This article reviews the development history,charac-teristics and clinical applications of Chirp ABR,and envisions its application prospects in forensic audi-tory identification.

ObjectiveTo investigate the role of 4-week high-intensity interval training (HIIT) in modulating the metabolic homeostasis of the pyruvate-lactate axis in the hippocampus of rats with chronic unpredictable mild stress (CUMS) to improve their depressive-like behavior. MethodsForty-eight SPF-grade 8-week-old male SD rats were randomly divided into 4 groups: the normal quiet group (C), the CUMS quiet group (M), the normal exercise group (HC), and the CUMS exercise group (HM). The M and HM groups received 8 weeks of CUMS modeling, while the HC and HM groups were exposed to 4 weeks of HIIT starting from the 5th week (3 min (85%-90%) S_max+1 min (50%-55%) S_max, 3-5 cycles, S_max is the maximum movement speed). A lactate analyzer was used to detect the blood lactate concentration in the quiet state of rats in the HC and HM groups at week 4 and in the 0, 2, 4, 8, 12, and 24 h after exercise, as well as in the quiet state of rats in each group at week 8. Behavioral indexes such as sucrose preference rate, number of times of uprightness and number of traversing frames in the absenteeism experiment, and other behavioral indexes were used to assess the depressive-like behavior of the rats at week 4 and week 8. The rats were anesthetized on the next day after the behavioral test in week 8, and hippocampal tissues were taken for assay. LC-MS non-targeted metabolomics, target quantification, ELISA and Western blot were used to detect the changes in metabolite content, lactate and pyruvate concentration, the content of key metabolic enzymes in the pyruvate-lactate axis, and the protein expression levels of monocarboxylate transporters (MCTs). Results4-week HIIT intervention significantly increased the sucrose preference rate, the number of uprights and the number of traversed frames in the absent field experiment in CUMS rats; non-targeted metabolomics assay found that 21 metabolites were significantly changed in group M compared to group C, and 14 and 11 differential metabolites were significantly dialed back in the HC and HM groups, respectively, after the 4-week HIIT intervention; the quantitative results of the targeting showed that, compared to group C, lactate concentration in the hippocampal tissues of M group, compared with group C, lactate concentration in hippocampal tissue was significantly reduced and pyruvate concentration was significantly increased, and 4-week HIIT intervention significantly increased the concentration of lactate and pyruvate in hippocampal tissue of HM group; the trend of changes in blood lactate concentration was consistent with the change in lactate concentration in hippocampal tissue; compared with group C, the LDHB content of group M was significantly increased, the content of PKM2 and PDH, as well as the protein expression level of MCT2 and MCT4 were significantly reduced. The 4-week HIIT intervention upregulated the PKM2 and PDH content as well as the protein expression levels of MCT2 and MCT4 in the HM group. ConclusionThe 4-week HIIT intervention upregulated blood lactate concentration and PKM2 and PDH metabolizing enzymes in hippocampal tissues of CUMS rats, and upregulated the expression of MCT2 and MCT4 transport carrier proteins to promote central lactate uptake and utilization, which regulated metabolic homeostasis of the pyruvate-lactate axis and improved depressive-like behaviors.

ObjectiveThis study aimed to investigate the effects of 4-week high-intensity interval training (HIIT) on synaptic plasticity in the prefrontal cortex (PFC) of rats exposed to chronic unpredictable mild stress (CUMS), and to explore its potential mechanisms. MethodsA total of 48 male Sprague-Dawley rats were randomly divided into 4 groups: control (C), model (M), control plus HIIT (HC), and model plus HIIT (HM). Rats in groups M and HM underwent 8 weeks of CUMS to establish depression-like behaviors, while groups HC and HM received HIIT intervention beginning from the 5th week for 4 consecutive weeks. The HIIT protocol consisted of repeated intervals of 3 min at high speed (85%-90% maximal training speed, S_max) alternated with one minute at low speed (50%-55% S_max), with 3 to 5 sets per session, conducted 5 d per week. Behavioral assessments and tail-vein blood lactate levels were measured at the end of the 4th and 8th weeks. After the intervention, rat PFC tissues were collected for Golgi staining to analyze synaptic morphology. Enzyme-linked immunosorbent assays (ELISA) were employed to detect brain-derived neurotrophic factor (BDNF), monocarboxylate transporter 1 (MCT1), lactate, and glutamate levels in the PFC, as well as serotonin (5-HT) levels in serum. Additionally, Western blot analysis was conducted to quantify the expression of synaptic plasticity-related proteins, including c-Fos, activity-regulated cytoskeleton-associated protein (Arc), and N-methyl-D-aspartate receptor 1 (NMDAR1). ResultsCompared to the control group (C), the CUMS-exposed rats (group M) exhibited significant reductions in sucrose preference rates, number of grid crossings, frequency of upright postures, and entries into and duration spent in open arms of the elevated plus maze, indicating marked depressive-like behaviors. Additionally, the group M showed significantly reduced dendritic spine density in the PFC, along with elevated levels of c-Fos, Arc, NMDAR1 protein expression, and increased concentrations of lactate and glutamate. Conversely, BDNF and MCT1 contents in the PFC and 5-HT levels in serum were significantly decreased. Following HIIT intervention, rats in the group HM displayed considerable improvement in behavioral indicators compared with the group M, accompanied by significant elevations in PFC MCT1 and lactate concentrations. Furthermore, HIIT notably normalized the expression levels of c-Fos, Arc, NMDAR1, as well as glutamate and BDNF contents in the PFC. Synaptic spine density also exhibited significant recovery. ConclusionFour weeks of HIIT intervention may alleviate depressive-like behaviors in CUMS rats by increasing lactate levels and reducing glutamate concentration in the PFC, thereby downregulating the overexpression of NMDAR, attenuating excitotoxicity, and enhancing synaptic plasticity.