Background Toluene and chlorobenzene have been designated as surrogate contaminants in the challenge test for evaluating the safety of recycling processes for food-contact recycled polyethylene terephthalate (rPET). Establishing a reliable analytical method is essential for ensuring the compliant use of rPET and safeguarding food safety. Objective To develop a rapid quantitative method for determining toluene and chlorobenzene in rPET using headspace gas chromatography-mass spectrometry (HS-GC-MS), as part of the challenge test for process safety evaluation. Methods The effects of different chromatographic columns and headspace conditions on detection of target analytes were investigated. Three columns HP-5 ms UI (30 m×0.25 mm×0.25 μm), DB-624 (30 m×0.32 mm×1.8 μm), and VF-WAXms (30 m×0.25 mm×0.25 μm) were compared for separation efficiency and peak shape. Headspace equilibration temperatures (50-100 ℃) and equilibration times (10-30 min) were evaluated to determine the optimal instrumental parameters. The effect of sample grinding on recovery was assessed to select the best pretreatment conditions. The established method was validated for selectivity, linearity, sensitivity, accuracy, and precision, and was subsequently applied to the analysis of 12 rPET samples. Results The target analytes achieved good separation and response within 15 min, under the optimized conditions using an HP-5 ms UI column, a headspace equilibration temperature of 60 ℃ and a 10 min equilibration time. Direct analysis without grinding yielded satisfactory recovery rates. Toluene and chlorobenzene showed excellent linearity (0.0030-5.0 mg·kg⁻¹, R²≥0.999). The limits of detection (LOD) and quantification (LOQ) were 0.00003 mg·kg⁻¹ and 0.00011 mg·kg⁻¹ for toluene respectively, and 0.00011 mg·kg⁻¹ and 0.00037 mg·kg⁻¹ for chlorobenzene respectively. The recoveries of the matrix spike at low and high spiking levels ranged from 88.6% to 110%, with relative standard deviations of 0.52%-4.9% (n=6). Among the 12 rPET samples from different recycling stages, three samples contained detectable levels of toluene (0.196-0.250 mg·kg⁻¹) and chlorobenzene (0.704-0.867 mg·kg⁻¹). Conclusion The proposed method is simple, rapid, highly sensitive, and accurate, making it suitable for determining toluene and chlorobenzene in food-contact rPET. It provides a robust technical approach for the safety evaluation of rPET recycling processes.

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.

Bronchiolar adenoma (BA) is a rare type of lung tumor characterized by bilayered epithelial cells having a continuous basal layer and a luminal layer. It resembles mucinous adenocarcinoma (MA) on frozen section, with difficulty in distinguishing the basal layer. Immunohistochemistry is the best choice for verifying the diagnosis. This study aimed to comprehensively characterize three cases of BA-combined carcinoma using clinical, histopathological, and genetic features. BA and carcinoma sections were subjected to next-generation sequencing, respectively. It was hypothesized that while different mutation forms matched different regions, BA and lung adenocarcinoma shared the same gene mutation when they co-occurred in the same location. BA with extensive carcinoma is extremely rare and presents diagnostic challenges due to its overlap with conditions such as MA. Because of its distinctive morphological characteristics, BA may be regarded as a low-grade malignancy, particularly during a confusing evaluation. A multifaceted examination of clinical, radiological, immunohistochemical, and genetic data is necessary for an accurate diagnosis.

Objective To evaluate the clinical characteristics, diagnostic reasoning, and therapeutic strategies of prostatic paraganglioma (PPG) to provide an evidence-based foundation for early diagnosis and precision treatment of this rare malignancy. Methods The clinical data of a patient with PPG admitted to our hospital were retrospectively analyzed. Concurrently, a systematic search was conducted across domestic and international databases, including PubMed, CNKI, and Wanfang.Clinical manifestations, laboratory tests, pathological features, therapeutic modalities, and prognostic data of 24 cases reported between 1979 and 2025 were pooled with the institutional case for a comprehensive analysis (n=25). Results Epidemiological features: the age at onset ranged from 8 to 76 years, with a mean age of (44.6±15.2) years, predominantly affecting young and middle-aged adults (30-50 years).Notably, 20.0% (5/25) of the patients exhibited characteristic micturition-associated catecholamine release symptoms (e.g., post-micturition palpitations, transient hypertension).Laboratory findings: among the 19 patients who underwent catecholamine metabolite testing, 14 (73.7%) showed significant elevation in serum or urinary norepinephrine and methoxyadrenaline levels.Pathological and immunohistochemical features: the positivity rate for neuroendocrine markers (chromogranin A, synaptophysin, and neuron-specific enolase) was 100%, while the negativity rate for prostate-specific markers (prostate-specific antigen and prostate-specific acid phosphatase) was also 100%.Treatment and prognosis: surgical intervention was performed in 96.0% (24/25) of the patients, including radical prostatectomy (37.5%), precision tumor excision (25.0%), and transurethral resection (12.5%).Favorable outcomes without recurrence were observed in 89.5% (17/19) of the total cohort. Conclusion PPG is clinically exceedingly rare.The disease should be highly suspected in patients presenting with a prostatic mass, normal prostate-specific antigen level, and micturition-associated cardiovascular symptoms.Testing for catecholamine metabolites is the key screening tool.Robot-assisted surgery facilitates precise tumor excision while ensuring optimal functional preservation.Given the malignant potential and genetic correlations of PPG, lifelong follow-up is recommended.

Radiotherapy is a cornerstone in the treatment of malignant tumors. It induces DNA damage through high-energy radiation, preferentially eliminating rapidly proliferating tumor cells. However, its clinical efficacy is often limited by tumor radioresistance and collateral damage to normal tissues. Consequently, elucidating the cellular response mechanisms to radiation stress and identifying key targets that can both sensitize tumor cells and protect normal tissues have become critical strategies for improving radiotherapy outcomes. Radiation stress triggers structural remodeling of the nucleolus, leading to the dissociation of certain ribosomal proteins from the ribosome and enabling them to acquire extra-ribosomal functions. Among these, RPL11 can be released and specifically binds to MDM2, thus inhibiting its E3 ubiquitin ligase activity, stabilizing p53, and mediating cell cycle arrest and apoptosis. The RPL11-MDM2-p53 pathway, acting as a signaling hub that links nucleolar dysfunction to cell fate determination, plays a pivotal role in maintaining genomic stability and regulating cellular responses to radiation. This review first introduces the basic characteristics of RPL11 and elucidates the molecular basis of radiation-induced ribosomal stress. It then outlines the core regulatory mechanisms of the cell cycle. On this basis, it focuses on the mechanisms by which radiation-induced RPL11 regulates the cell cycle and analyzes the specific effects of RPL11 on cell cycle. Furthermore, it discusses the role of the RPL11-MDM2-p53 pathway in cell cycle regulation. Finally, it explores the role of this pathway in maintaining genomic stability and determining cell fate, and highlights its potential value as a target for radiosensitization, aiming to provide new perspectives for enhancing tumor radiosensitivity and reducing damage to normal tissues.

Radiotherapy is a cornerstone in the treatment of malignant tumors. It induces DNA damage through high-energy radiation, preferentially eliminating rapidly proliferating tumor cells. However, its clinical efficacy is often limited by tumor radioresistance and collateral damage to normal tissues. Consequently, elucidating the cellular response mechanisms to radiation stress and identifying key targets that can both sensitize tumor cells and protect normal tissues have become critical strategies for improving radiotherapy outcomes. Radiation stress triggers structural remodeling of the nucleolus, leading to the dissociation of certain ribosomal proteins from the ribosome and enabling them to acquire extra-ribosomal functions. Among these, RPL11 can be released and specifically binds to MDM2, thus inhibiting its E3 ubiquitin ligase activity, stabilizing p53, and mediating cell cycle arrest and apoptosis. The RPL11-MDM2-p53 pathway, acting as a signaling hub that links nucleolar dysfunction to cell fate determination, plays a pivotal role in maintaining genomic stability and regulating cellular responses to radiation. This review first introduces the basic characteristics of RPL11 and elucidates the molecular basis of radiation-induced ribosomal stress. It then outlines the core regulatory mechanisms of the cell cycle. On this basis, it focuses on the mechanisms by which radiation-induced RPL11 regulates the cell cycle and analyzes the specific effects of RPL11 on cell cycle. Furthermore, it discusses the role of the RPL11-MDM2-p53 pathway in cell cycle regulation. Finally, it explores the role of this pathway in maintaining genomic stability and determining cell fate, and highlights its potential value as a target for radiosensitization, aiming to provide new perspectives for enhancing tumor radiosensitivity and reducing damage to normal tissues.

Radiotherapy is a cornerstone in the treatment of malignant tumors. It induces DNA damage through high-energy radiation, preferentially eliminating rapidly proliferating tumor cells. However, its clinical efficacy is often limited by tumor radioresistance and collateral damage to normal tissues. Consequently, elucidating the cellular response mechanisms to radiation stress and identifying key targets that can both sensitize tumor cells and protect normal tissues have become critical strategies for improving radiotherapy outcomes. Radiation stress triggers structural remodeling of the nucleolus, leading to the dissociation of certain ribosomal proteins from the ribosome and enabling them to acquire extra-ribosomal functions. Among these, RPL11 can be released and specifically binds to MDM2, thus inhibiting its E3 ubiquitin ligase activity, stabilizing p53, and mediating cell cycle arrest and apoptosis. The RPL11-MDM2-p53 pathway, acting as a signaling hub that links nucleolar dysfunction to cell fate determination, plays a pivotal role in maintaining genomic stability and regulating cellular responses to radiation. This review first introduces the basic characteristics of RPL11 and elucidates the molecular basis of radiation-induced ribosomal stress. It then outlines the core regulatory mechanisms of the cell cycle. On this basis, it focuses on the mechanisms by which radiation-induced RPL11 regulates the cell cycle and analyzes the specific effects of RPL11 on cell cycle. Furthermore, it discusses the role of the RPL11-MDM2-p53 pathway in cell cycle regulation. Finally, it explores the role of this pathway in maintaining genomic stability and determining cell fate, and highlights its potential value as a target for radiosensitization, aiming to provide new perspectives for enhancing tumor radiosensitivity and reducing damage to normal tissues.

ObjectiveTo summarize the application experience of the "Three-Separation" model in the pre-service training of laboratory animal practitioners and scientifically evaluate its training effectiveness. MethodsA retrospective analysis was conducted on 8 009 practitioners who participated in pre-service training at the Fujian Provincial Laboratory Animal Training Base from January 2010 to December 2025. Among them, 1 250 trainees from January 2010 to December 2017 were included in the control group (traditional training model), and 6 759 trainees from January 2018 to December 2025 were included in the evaluation group ("Three-Separation" model, based on separating job requirements, differentiating exam content, and categorizing exam methods). Meanwhile, a questionnaire survey was conducted to evaluate training effectiveness, yielding 1 624 valid questionnaires (585 from the control group and 1 039 from the evaluation group). The "Three-Separation" model simultaneously optimized fee structures to improve affordability and inclusiveness. The comprehensive competencies and training satisfaction of the two groups after training were compared and analyzed using the independent sample t-test, χ² test, and Wilcoxon rank-sum test. ResultsThe overall satisfaction rate of the evaluation group was 92.49% (961/1 039), significantly higher than that of the control group (77.78%, 455/585), with a highly significant difference (χ²=72.50, P<0.001). The evaluation group showed a more favorable distribution of positive, neutral, and negative ratings in dimensions such as course pertinence, time flexibility, assessment rationality, and reasonableness of fees, and the positive rating rates were highly significantly higher than those in the control group (P<0.001). The comprehensive pass rate of the evaluation group (95.53%) was significantly higher than that of the control group (86.24%), with a highly significant difference (P<0.001). ConclusionThe scientific application of the "Three-Separation" model can accurately match the competency requirements of different positions, optimize the training and assessment system, reduce participation barriers by making training fees more affordable and accessible, effectively improve the comprehensive quality and training satisfaction of laboratory animal practitioners, achieve better teaching outcomes, and provide replicable and promotable practical references for the standardized upgrading of the training system in the laboratory animal industry and other industries.

ObjectiveTo investigate the effect and mechanism of Shuangshen Ningxin capsules （SSNX） in regulating the nuclear factor-κB （NF-κB） and mitogen-activated protein kinase （MAPK） pathways to inhibit inflammation and alleviate myocardial ischemia-reperfusion injury （MIRI） in rats. MethodsThe 45 healthy male Sprague-Dawley （SD） rats were divided into sham operation group， model group， and SSNX capsules group （90 mg·kg^-1）. The left anterior descending coronary artery was ligated to establish the MIRI model. Cardiac function was evaluated by echocardiography， and microvascular reperfusion was analyzed using contrast echocardiography. Myocardial inflammation and injury were assessed by hematoxylin and eosin （HE） staining， immunohistochemistry， and TdT-mediated dUTP nick end labeling （TUNEL）. The expression levels of cardiac inflammatory cytokines， including interleukin-1α （IL-1α）， interleukin-6 （IL-6）， and tumor necrosis factor-α （TNF-α） were detected by enzyme-linked immunosorbent assay （ELISA）. Core differentially expressed genes （DEGs） and enriched pathways were screened by transcriptome sequencing. Real-time quantitative polymerase chain reaction （Real-time PCR） and Western blot were used to verify the mRNA expression of Toll-like receptor 2 （TLR2）， chemokine （C-X-C motif） ligand 1 （CXCL1） and prostaglandin-endoperoxide synthase 2 （PTGS2）， as well as the protein expression of Caspase-3， cleaved Caspase-3， p-NF-κB/NF-κB， phosphorylated extracellular signal-regulated kinase 1/2 （p-ERK1/2/ERK1/2） and p-p38 MAPK/p38 MAPK. ResultsCompared with the sham operation group， the ejection fraction （EF）， fractional shortening （FS）， stroke volume （SV） and cardiac output （CO） of the model group were significantly decreased （P<0.01）， the peak time of myocardial perfusion was prolonged （P<0.01）， hypoxia-inducible factor （HIF）-1α and α-smooth muscle actin （SMA） expression increased （P<0.01）， the concentrations of inflammatory factors IL-1α， IL-6， TNF-α， TLR2， CXCL1 and PTGS2 increased （P<0.01）， and the expression of cleaved Caspase-3， p-NF-κB/NF-κB， p-ERK1/2/ERK1/2 and p-p38 MAPK/p38 MAPK proteins was significantly increased （P<0.01）. SSNX could improve cardiac function （P<0.05， P<0.01）， and significantly shorten the peak time of myocardial perfusion （P<0.01）. Moreover， it could also down-regulate HIF-1α and a-SMA expression （P<0.05， P<0.01）， and reduce the concentrations of IL-1α， IL-6， TNF-α （P<0.01）， and the mRNA expression of TLR2， CXCL1 and PTGS2 （P<0.01）. Additionally， SSNX inhibited the apoptosis rate （P<0.01） and significantly reduced the expression of Cleaved Caspase-3， p-NF-κB/NF-κB， p-ERK1/2/ERK1/2 and p-p38 MAPK/p38 MAPK proteins （P<0.01）. ConclusionSSNX can alleviate cardiac inflammation by regulating the NF-κB and MAPK signaling pathways， thereby effectively preventing and alleviating myocardial reperfusion injury.