1.Postoperative lower limb ischemic necrosis following xenogeneic heart transplantation from gene-edited pigs to rhesus macaques
Xianzhi WANG ; Zhipeng REN ; Ziqiang DAI ; Rong ZHOU ; Gen ZHANG ; Jie YAN ; Yulong GUAN ; Guangyu PAN ; Xingzhuang HE ; Tingting LIU ; Shangxuan LI ; Guanzheng CUI ; Chenghong LAI ; Dengke PAN ; Dianyuan LI
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2026;33(09):1474-1481
Objective To investigate the causes and management strategies for lower limb ischemic necrosis following xenogeneic heterotopic heart transplantation from a multigene-edited pig to a rhesus monkey. Methods A xenogeneic heterotopic heart transplantation was performed on December 16, 2023, at the Institute of Experimental Animals of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, using a quintuple-gene-edited pig as the donor and a rhesus monkey as the recipient. On postoperative day (POD) 9, the recipient monkey underwent left lower limb amputation due to ischemic necrosis. Blood samples were collected at various time points after transplantation for analysis of hematologic parameters, liver and renal function, myocardial enzymes, and coagulation profiles. Ultrasound and computed tomography (CT) were used to evaluate anastomotic patency and cardiac structure. Immunological assays, including complement-dependent cytotoxicity (CDC) and IgG/IgM antibody detection, combined with clinical observations, were employed to assess rejection type and therapeutic response. Results The recipient monkey survived for 46 days after transplantation. Echocardiography demonstrated preserved biventricular systolic function in the recipient’s native heart, with left ventricular ejection fraction (LVEF) consistently exceeding 50%. In the donor pig heart, left ventricular endocardial thickening was noted on POD 9, followed by right ventricular endocardial thickening on POD 24, while LVEF remained around 35%. No hyperacute or acute rejection was detected immunologically. CDC positivity ranged between 3.4% and 5.1%, with IgG/IgM antibody binding trends consistent with CDC results. Following amputation, the recipient exhibited elevated inflammatory markers, coagulopathy, and reactive thrombocytosis, which later normalized. Immunohistochemical staining of the necrotic limb revealed arterial and venous thrombosis; however, no T-cell or B-cell infiltration was observed in vascular structures, thrombi, nerves, muscles, fascia, or skin tissues, with CD3 and CD20 staining both negative. Conclusion Limb ischemia after xenogeneic heart transplantation may be associated with lower extremity vascular thrombosis triggered by local trauma in the context of transplantation-induced inflammatory activation and coagulation dysfunction. While no clear lymphocyte-mediated rejection was observed, further studies are needed to explore the potential role of non-lymphocyte-mediated immune mechanisms.
2.Analyzing the influencing factors of work-related musculoskeletal disorders among construction workers
Maosheng YAN ; Xiongda HE ; Chunshuo CHEN ; Ning JIA ; Junle WU ; Guoyong XU ; Hua YAN ; Zhipeng HE ; Yongjian JIANG ; Jianyu GUO ; Bin XIAO
China Occupational Medicine 2025;52(5):503-510
Objective To investigate the prevalence and risk factors of work-related musculoskeletal disorders (WMSDs) among construction workers. Methods A total of 5 783 workers were selected as participants from 12 construction companies in Guangdong Province, Guangxi Zhuang Autonomous Region and Zhejiang Province using a convenient sampling method. The revised Musculoskeletal Disorders Questionnaire was used to investigate the prevalence and influencing factors of WMSDs. Results The prevalence of WMSDs was 27.4% among the construction workers. The prevalence of WMSDs in shoulder, neck, waist/lower back and hand/wrist was 10.6%, 9.5%, 9.5% and 9.4% respectively, which was higher than that in other body parts. Bianry logistic regression analysis showed that the risk of WMSDs in construction workers with junior high school education and below was higher than that of high school/ college and above (P<0.05). The risk of WMSDs was higher in drinkers than that in non-drinkers (P<0.01). The worse the health status of construction workers, the higher the risk of WMSDs (P<0.01). The risk of WMSDs in those who exercised once or twice a month was lower than that in those who did not exercise (P<0.05). The risk of WMSDs was higher in construction workers with longer working hours in uncomfortable postures and greater back bending amplitude at work (all P<0.01). The risk of WMSDs in construction workers with hands holding above the shoulder was higher than that with hands below the shoulder (P<0.05). Construction workers who repeated the same work daily, involved in high-temperature work, often worked overtime, had insufficient rest time, and had a shortage of department personnel had a relatively high risk of WMSDs (all P<0.01). Conclusion The prevalence of WMSDs among the construction workers was relatively high, and the most common WMSDs occurred in shoulder, neck, waist/lower back and hand/wrist. Individual characteristic, work type, work posture and work organization are the influencing factors of WMSDs. Comprehensive measures, especially ergonomic measures based on personal and occupational characteristics should be taken to reduce the risk of WMSDs among construction workers.
3.Effect of hand transmitted vibration on fingertip thermotactile perception threshold in grinding workers
Danying ZHANG ; Maosheng YAN ; Hansheng LIN ; Sizhi CHEN ; Xuemei SONG ; Bin XIAO ; Hua YAN ; Guoyong XU ; Zhipeng HE
China Occupational Medicine 2025;52(5):540-544
Objective To analyze the effect of hand transmitted vibration on fingertip thermotactile perception threshold (TPT) among grinding workers in a sports equipment manufacturing enterprise. Methods A total of 151 male grinding workers from a sports equipment manufacturing enterprise in Guangdong Province were enrolled in the vibration exposure group, and 51 male workers without hand-transmitted vibration exposure were enrolled in the control group, using the judgment sampling method. Basic health conditions of the workers were surveyed in both groups. The TPTs of the distal phalanges of the index and little fingers on both hands were tested using an HVLab thermal perception tester. Results The detection rates of finger numbness and tingling among workers in the vibration exposure group were higher than those in the control group (92.1% vs 7.8% and 59.6% vs 0.0%, respectively, both P<0.01). The detection rates of numbness or tingling of different fingers in the vibration exposure group descended in the following order: index finger, middle finger, ring finger, thumb and little finger. The hot threshold of the index finger and little finger increased (all P<0.01), while the cold threshold decreased (all P<0.01) in the vibration exposure group, compared with the control group. The results of generalized linear regression analysis showed that with the increase of the duration of hand-transmitted vibration, the hot threshold of the index finger and the little finger of both hands increased (all P<0.01), and the cold threshold decreased (all P<0.01). The hot thresholds of workers with numbness of both the index fingers and left little finger were higher than those of workers without numbness of the same finger (all P<0.05). The hot threshold of workers with tingling of the left index finger was higher than those without tingling (P<0.05). The cold thresholds of workers with tingling of the both index fingers and left little finger were lower than those without tingling of the same finger (all P<0.05). The hot threshold of the right little finger increased with age (P<0.01), while the cold thresholds of both little fingers decreased with age (all P<0.01). Conclusion Hand-transmitted vibration exposure increases fingertip hot threshold and decreases fingertip cold threshold of workers exposed to hand-transmitted vibration. Years of service in hand-transmitted vibration work, finger numbness or tingling, and age were influencing factors of TPT. Fingertip TPT examination can be used to assist in the early detection of vibration-induced nerve injury in workers exposed to hand-transmitted vibration.
4.Prediction of Neoadjuvant Therapy Sensitivity in Rectal Cancer Patients based on Deep Imaging Omics Models
Guohong GAO ; Zhipeng DING ; Yan LI
Chinese Journal of Health Statistics 2025;42(5):661-665,671
Objective Exploring the performance of a sensitivity recognition model for neoadjuvant therapy based on ensemble learning algorithms for predicting neoadjuvant therapy sensitive patients.Methods In this study,255 rectal cancer patients who underwent standard neoadjuvant therapy and surgery at the Affiliated Cancer Hospital of Harbin Medical University were collected,of which 139 patients were sensitive to neoadjuvant therapy and 116 patients were not.The recursive feature elimination method was used to screen deep learning features and imaging histology features to construct an integrated learning model.The generalization performance of the model was verified using the leave-out method,and the sensitivity,specificity,positive predictive value,negative predictive value,accuracy,G-mean,F-measure,Mathews correlation coefficient(MCC),and area under the receiver operating charactpristic curve(AUC)were used to evaluate and compare the model performance.Results The performance of the integrated model on the external validation set was:an AUC value of 0.916(95%CI:0.899 to 0.935),a sensitivity of 1.000,a specificity of 0.833,a positive predictive value of 0.875,a negative predictive value of 1.000,an accuracy of 0.923,a G-mean of 0.913,an F-measure of 0.933,a MCC was 0.854.Conclusion The integration model of depth features and imaging omics features is superior to the individual depth feature model and imaging omics feature model,and has good practicality and reliability in identifying sensitive patients with neoadjuvant therapy,which can be used as a reference for clinical practice.
5.Relationship between preoperative body mass index and severe postoperative complications in patients with hepatolithiasis undergoing liver resection
Rui JIAN ; Chenxi LI ; Zhipeng LIU ; Xueer YANG ; Yule LUO ; Jie BAI ; Yan JIANG ; Yi GONG ; Haisu DAI ; Shuo JIN ; Zhiyu CHEN
Chinese Journal of General Surgery 2025;34(1):79-87
Background and Aims:Body mass index(BMI),an important indicator of nutrition and health,is closely associated with postoperative complications.This study was performed to investigate the relationship between preoperative BMI and severe complications in patients undergoing liver resection for hepatolithiasis,aiming to provide preoperative guidance for clinicians,reduce the risk of postoperative complications,and ensure surgical safety and efficacy.Methods:The clinical data of 484 patients with hepatolithiasis who underwent liver resection between May 2006 and December 2022 at the First Affiliated Hospital of Army Medical University and Beijing Tsinghua Changgung Hospital were retrospectively collected.Patients were classified into low BMI group(≤18.4 kg/m2),normal BMI group(18.5-24.9 kg/m2),and high BMI group(≥25.0 kg/m2)based on preoperative BMI.Baseline characteristics,overall complications,severe complications,and other postoperative outcomes were compared between the normal BMI group and the low group as well as the high BMI group.Risk factors for severe complications after liver resection were analyzed.Results:Among the 484 patients,79(16.3%)were in the low BMI group,328(67.8%)in the normal BMI group,and 77(15.9%)in the high BMI group.The high BMI group had significantly higher ASA score,preoperative albumin level,and proportion of hypertension compared to the normal BMI group(all P<0.05).Baseline characteristics in the low BMI group showed no significant differences compared to the normal BMI group(all P>0.05).The incidence rates of overall complications were not significantly among the three groups(P>0.05).However,the high BMI group had significantly higher incidence rates of severe complications(Clavien-Dindo grade Ⅲ-Ⅳ),postoperative infections,liver failure,and bile leakage compared to the normal BMI group;the low BMI group had significantly higher rates of perioperative blood transfusion,postoperative infections,liver failure,and reoperation compared to the normal BMI group(all P<0.05).Univariate and multivariate Logistic regression analyses identified high BMI and preoperative total bilirubin ≥54 pmol/L as independent risk factors for severe complications after liver resection in patients with hepatolithiasis(both P<0.05).Conclusion:Preoperative BMI is closely associated with the occurrence of complications after liver resection in patients with hepatolithiasis,with high BMI being an independent risk factor for severe complications.To mitigate the risk of severe complications,clinical practice should prioritize monitoring and management of individuals with high BMI and other risk factors
6.Piceatannol ameliorates diabetic retinopathy mediated by microglial polariza-tion via inhibition of the CXCR4/BTK pathway
Haiyan SUN ; Yu ZHAI ; Yuanqing ZHANG ; Jiaxuan ZHANG ; Zepeng ZHANG ; Zhipeng YAN ; Yun ZHANG
Recent Advances in Ophthalmology 2025;45(12):930-937
Objective To investigate whether Piceatannol(PIC)improves diabetic retinopathy(DR)mediated by microglial polarization and to elucidate the underlying molecular mechanisms.Methods Network pharmacology and bioinformatics were used to analyze the common targets of DR,PIC,and microglia.Human retinal vascular endothelial cells(HRVECs)were cultured in vitro and randomly divided into the NG-HRVECs group,HG-HRVECs group,and HG+PIC-HRVECs group.Cell viability was assessed by the CCK-8 assay,apoptosis was detected by the TUNEL assay,and the concentrations of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)were measured using ELISA kits.BV-2 cells were cultured in vitro and randomly divided into the NG-BV-2 group,HG-BV-2 group,HG+PIC-BV-2 group,HG+Si-NC-BV-2 group,HG+Si-CXCR4-BV-2 group,and HG+Ibrutinib-BV-2 group.The levels of arginase-1(Arg-1)and inducible ni-tric oxide synthase(iNOS)were measured using ELISA kits.Furthermore,conditioned medium(CM)from BV-2 cells of each group was collected to treat HRVECs,after which the viability,apoptosis rate,and TNF-α and IL-6 concentrations of the HRVECs were measured.A DR rat model was established and intervened with PIC to investigate the ameliorative effects of PIC on retinal pathology.Results Bioinformatics analysis identified CXCR4 as the key target of this study.Compared with the NG-HRVECs group,the apoptosis rate and the concentrations of TNF-α and IL-6 were increased in the HG-HRVECs group.Compared with the HG-HRVECs group,the HG+PIC-HRVECs group showed a decreased apoptosis rate and reduced concentrations of TNF-α and IL-6(all P<0.05).Compared with the NG-BV-2 group,the HG-BV-2 group ex-hibited decreased Arg-1 levels and increased iNOS levels.Compared with the HG-BV-2 group,the HG+PIC-BV-2,HG+Si-CXCR4-BV-2,and HG+Ibrutinib-BV-2 groups all showed increased Arg-1 levels and decreased iNOS levels(all P<0.05).Compared with the NG-BV-2-CM group,the HG-BV-2-CM group led to decreased viability,increased apoptosis rate,and in-creased concentrations of TNF-α and IL-6 in HRVECs.In contrast,the HG+PIC-BV-2-CM,HG+Si-CXCR4-BV-2-CM,and HG+Ibrutinib-BV-2-CM groups reversed the effects induced by HG-BV-2-CM on HRVECs(all P<0.05).Animal experiment results showed that compared with DR model rats,rats treated with different doses of PIC exhibited significantly ameliora-ted retinal histopathological damage,and the protein expressions of Arg-1,iNOS,CXCR4,and p-BTK were reversed.Con-clusion PIC ameliorates DR progression mediated by microglial polarization by inhibiting the CXCR4/BTK pathway.
7.Impact of postoperative complications on adverse outcomes following curative-intent resection for gallbladder cancer: a national multicenter real-world study
Zhipeng LIU ; Cheng CHEN ; Jie BAI ; Yan JIANG ; Dong ZHANG ; Wei GUO ; Zhixin WANG ; Xiang LAN ; Yufu YE ; Zhaoping WU ; Jinxue ZHOU ; Shuo JIN ; Yi ZHU ; Wei CHEN ; Dalong YIN ; Yao CHENG ; Haisu DAI ; Lei ZHANG ; Zhiyu CHEN
Chinese Journal of Digestive Surgery 2025;24(7):874-881
Objective:To investigate the impact of postoperative complications on adverse outcomes following curative-intent resection for gallbladder cancer (GBC).Methods:The multi-center real-world study was conducted. The clinicopathological data of 629 patients with GBC, who were admitted to 14 medical centers including The First Affiliated Hospital of Army Medical University from the national multicenter database of Biliary Surgery Group of Elite Group of Chinese Journal of Digestive Surgery, from April 2020 to April 2024 were collected. There were 225 males and 404 females, aged (64±10)years. Patients underwent open curative-intent resection for GBC. Observation indicators: (1)surgery, postoperative complica-tions and adverse outcomes; (2) analysis of risk factors affecting postoperative adverse outcomes in patients and population attributable fraction (PAF). Missing data in predictor variables were addressed using multiple imputation with chained equations, while cases with missing outcome variables were addressed using the "multiple imputation then deletion (MID)" strategy. The severity of multicollinearity among independent variables was assessed using the variance inflation factor (VIF) test. Multivariable possion regression models with log link and robust error variance were construc-ted incorporating restricted cubic splines (3 knots) to address nonlinear relationships in continuous variables, calculating adjusted relative risk ( RR) with corresponding 95% confidence interval ( CI). Adjusted PAF was calculated for each imputed dataset using the AF package of R software, with subsequent pooling performed according to Rubin's rules. Results:(1) Surgery, postoperative complications and adverse outcomes. All 629 patients underwent curative-intent resection for GBC, of which 143 cases had postoperative complications, including 68 cases of intra-abdominal ascites, 39 cases of pulmonary infection, 21 cases of bile leakage, 12 cases of intra-abdominal hemorrhage, 11 cases of liver failure, 10 cases of pan-creatic fistula, 10 cases of wound infection, 10 cases of gastroparesis, 7 cases of cholangitis, 7 cases of sepsis. The same patient could have more than one kind of complication. Of 629 patients, there were 19 cases of postoperative 90-day death and 11 cases of missing data, 42 cases with post-operative 90-day reoperation and 7 cases with missing data, 44 cases with postoperative 90-day readmission and 3 cases with missing data, 155 cases with prolonged postoperative hospital stay and 3 cases with missing data. (2) Analysis of risk factors affecting the postoperative adverse outcomes in patients and PAF. Results of multivariate analysis showed that pulmonary infection and liver failure were independent risk factors for postoperative 90-day mortality ( RR=3.74, 12.15, 95% CI as 1.18-11.83, 1.98-74.48, P<0.05). Pulmonary infection demons-trated the highest PAF as 4.61% (95% CI as 3.94%-5.28%, P<0.05). Intra-abdominal ascites, pulmonary infection, bile leakage, and intra-abdominal hemorrhage were independent risk factors for post-operative 90-day reoperation ( RR=4.80, 3.62, 3.46, 4.99, 95% CI as 2.49-9.26, 1.42-9.21, 1.34-8.92, 1.55-16.06, P<0.05). Intra-abdominal ascites demonstrated the highest PAF as 8.65% (95% CI as 8.22%-9.08%, P<0.05). Intra-abdominal ascites, bile leakage, and liver failure were independent risk factors for postoperative 90-day readmission ( RR=6.20, 3.33, 14.33, 95% CI as 3.21-11.95, 1.33-8.35, 3.72-55.28, P<0.05). Intra-abdominal ascites demonstrated the highest PAF as 9.11% (95% CI as 8.85%-9.37%, P<0.05). Intra-abdominal ascites, pulmonary infection, bile leakage, liver failure, and wound infection were independent risk factors for prolonged postoperative hospital stay ( RR=2.29, 2.21, 2.26, 2.14, 3.35, 95% CI as 1.63-3.23, 1.41-3.46, 1.32-3.86, 1.11-4.13, 1.70-6.60, P<0.05). Intra-abdominal ascites demonstrated the highest PAF as 6.03% (95% CI as 5.71%-6.35%, P<0.05). Conclusion:Pulmonary infection is the most significant risk factor for postoperative 90-day mortality after curative-intent resection for GBC, while intra-abdominal ascites is the most significant risk factor for postoperative 90-day reoperation, postoperative 90-day readmission, and prolonged postoperative hospital stay.
8.Impact of metabolic syndrome on perioperative and long-term outcomes after radical resection for perihilar cholangiocarcinoma
Ke MIN ; Zimu LI ; Zhipeng LIU ; Haisu DAI ; Jie BAI ; Yan JIANG ; Zhiyu CHEN
Chinese Journal of General Surgery 2025;34(8):1671-1679
Background and Aims:Perihilar cholangiocarcinoma(pCCA)is associated with poor prognosis.Radical resection remains the mainstay of treatment;however,high recurrence rates and limited overall survival(OS)after surgery.Metabolic syndrome(MetS)has been linked to unfavorable outcomes in various malignancies,but its impact on postoperative outcomes in pCCA is unclear.This study aimed to evaluate the influence of MetS on perioperative and long-term outcomes in patients undergoing radical resection for pCCA.Methods:A retrospective analysis was conducted on 223 patients who underwent radical resection for pCCA at the First Affiliated Hospital of Army Medical University between January 2018 and December 2023.Patients were categorized into a MetS group(n=50)and a non-MetS group(n=173)according to diagnostic criteria.Perioperative complications,overall survival(OS),and recurrence-free survival(RFS)were compared between groups.Prognostic factors were identified using multivariate analysis.Results:No significant differences were observed between the two groups regarding median hospital stay,overall complications,or severe complications(all P>0.05).The 1-,3-,and 5-year OS rates in the MetS group were 62.3%,22.3%,and 0,respectively,compared with 78.2%,39.5%,and 22.0%in the non-MetS group.Corresponding RFS rates were 46.2%,16.9%,and 0 in the MetS group vs.63.8%,29.6%,and 18.8%in the non-MetS group.Median OS and RFS were significantly shorter in the MetS group than in the non-MetS group(15.0 vs.27.0 months;12.0 vs.21.0 months;P=0.021 and P=0.037,respectively).Multivariate analysis identified MetS and major vascular invasion as independent predictors of OS,while MetS,jaundice,R0 resection,and major vascular invasion were independent predictors of RFS(all P<0.05).Conclusion:MetS is significantly associated with worse long-term survival and higher recurrence risk after radical resection for pCCA.Incorporating MetS into preoperative assessment and postoperative management strategies may help improve patient outcomes.
9.Huoxue Jiedu Formulas (活血解毒方药) as an Adjunctive Therapy for Patients with Binding of Stasis and Toxin Syndrome during the Vulnerable Period after Myocardial Infarction:A Prospective Real-World Study
Xiaofei GENG ; Yingxi YANG ; Zhipeng YAN ; Xinbiao FAN ; Xitong SUN ; Boyu ZHU ; Zheng ZHANG ; Yongchun LIANG ; Xiaoyu SHAN ; Junping ZHANG
Journal of Traditional Chinese Medicine 2025;66(23):2467-2474
ObjectiveTo observe the efficacy of Huoxue Jiedu Formulas (活血解毒方药, HJF) as an adjunctive treatement for patients with binding of stasis and toxin syndrome during the vulnerable period after acute myocardial infarction (AMI) percutaneous coronary intervention (PCI) surgery, and to explore its potential mechanism from the perspective of serum neutrophil extracellular traps (NETs). MethodsA total of 129 patients with binding of stasis and toxin syndrome within 6 months after PCI for AMI were enrolled and divided into a treatment group (65 cases) and a control group (64 cases) based on patients' willingness to take Chinese herbal medicine. The control group received standard western medical therapy alone, while the treatment group additionally received HJF, one dose daily. Both groups were treated for four weeks. Before and after treatment, TCM syndrome scores were assessed. Seattle angina questionnaire (SAQ) was used to record angina stability and frequency scores, while the short form-36 health survey (SF-36) was employed to assess quality of life across eight dimensions, including physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health. The Pittsburgh sleep quality index (PSQI) was used to evaluate sleep quality, and the patient health questionnaire-15 (PHQ-15) was used to assess psychosomatic symptoms; Duke activity status index (DASI) was used to measure daily physical activity. Serum levels of neutrophil extracellular traps (NET) markers including myeloperoxidase-DNA (MPO-DNA), neutrophil elastase-DNA (NE-DNA), and citrullinated histone H3 (CitH3) were measured in 20 patients from the treatment group. ResultsAfter treatment, TCM syndrome score, PSQI score and PHQ-15 score in both groups significantly decreased, while DASI score, angina stability and frequency scores, and all eight dimensions of the SF-36 scale significantly increased (P<0.05). Compared to the control group, the treatment group had significantly lower TCM syndrome scores and significantly higher DASI, angina stability and frequency scores (P<0.05), as well as higher scores in the SF-36 dimensions of physical functioning, role-physical, social functioning, bodily pain, and vitality (P<0.05). After treatment, serum levels of MPO-DNA, CitH3, and NE-DNA in the treatment group were significantly reduced (P<0.05). ConclusionHJF combined with conventional therapy can significantly improve angina symptoms, TCM syndrome scores, and psychosomatic conditions in patients with binding of stasis and toxin syndrome during the vulnerable period after AMI. It also enhances quality of life, sleep quality, and daily physical activity. The underlying mechanism may be associated with the inhibition of serum NETs level.
10.Role and mechanism of dexmedetomidine in regulating bone metabolism in tail-suspended osteoporotic rats
Yunliang GUO ; Can WANG ; Xinyu ZHANG ; Zedong YAN ; Zhipeng WEN ; Ruobing LIU ; Pengsen LIU
Journal of Army Medical University 2025;47(3):226-233
Objective To investigate the effect of dexmedetomidine(Dex)on bone loss in tail-suspended rats and primarily explore its regulatory mechanism on bone metabolism.Methods A total of 30 male rats were randomly divided into a control group,a model group,and a Dex group,with 10 animals in each group.Rat model of osteoporosis was established by hind limb suspension for 4 weeks.Dex at a dose of 10 μg/kg was given intraperitoneally,once every other day from the day of tail suspension.And equal amount of normal saline was given to the control and model group.Bone histological staining was used to observe the trabecular bone area fraction.Biomechanical three-point bending test was employed to measure the maximum load,stiffness,and fracture energy.Dual calcein/alizarin red fluorescence labeling and tartrate resistant acid phosphatase(TRAP)staining were applied respectively to detect the mineral apposition rate and bone formation rate as well as the number of osteoclasts on bone surfaces.Secondly,after primary osteoblasts were isolated from the tibiae of tail-suspended rats and then treated with 1 nmol/L Dex,the proportion of alkaline phosphatase(ALP)-positive osteoblasts and the activity of the enzyme were detected by ALP staining and activity test.qRT-PCR was applied to measure the expression of osteogenic activity-related factors,including osteocalcin(Ocn),Runt related transcription factor 2(Runx2),Osterix protein(Osx),and type 1 collagen(Col1).Results The animal experiments revealed that Dex treatment significantly increased the tibial trabecular bone area fraction,inhibited the decrease in bone mechanical strength,and enhanced the mineralization deposition rate and new bone formation rate of trabecular bone in the tail-suspended rats(all P<0.001).The in vitro experiments showed that Dex treatment obviously improved ALP activity and the number of ALP-positive osteoblasts in primary osteoblasts isolated from tail-suspended rats(P<0.01),and up-regulated the expression levels of osteogenic differentiation-related genes,such as Ocn,Runx2,Osx and Col1(P<0.01).Conclusion Dex exerts anti-bone loss effect in tail-suspended rats,which may be associated with its stimulation on osteoblast-mediated bone formation.

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