ObjectiveTo investigate the effect of Danggui Shaoyaosan on ferroptosis in the rat model of non-alcoholic fatty liver disease （NAFLD） and explore the underlying mechanism based on the nuclear factor E₂-related factor 2 （Nrf2）/solute carrier family 7 member 11 （SLC7A11）/glutathione peroxidase 4 （GPX4） signaling pathway. MethodsThe sixty SD rats were randomly grouped as follows： control， model， Yishanfu （0.144 g·kg^-1）， and low-， medium-， and high-dose （2.44， 4.88， and 9.76 g·kg^-1， respectively） Danggui Shaoyaosan. A high-fat diet was used to establish the rat model of NAFLD. After 12 weeks of modeling， rats were treated with corresponding agents for 4 weeks. Then， the body weight and liver weight were measured， and the liver index was calculated. At the same time， serum and liver samples were collected. The levels or activities of total cholesterol （TC）， triglycerides （TG）， alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， and Fe²⁺ in the serum and TC， TG， free fatty acids （FFA）， malondialdehyde （MDA）， superoxide dismutase （SOD）， glutathione peroxidase （GPX）， and Fe²⁺ in the liver were measured. Hematoxylin-eosin staining and oil red O staining were employed to observe the pathological changes in the liver. Immunofluorescence was used to assess the reactive oxygen species （ROS） content in the liver. Mitochondrial morphology was observed by transmission electron microscopy. The protein levels of Nrf2， SLC7A11， GPX4， transferrin receptor 1 （TFR1）， and divalent metal transporter 1 （DMT1） in the liver were determined by Western blot. ResultsCompared with the control group， the model group showed increases in the body weight， liver weight， liver index， levels or activities of TC， TG， ALT， AST， and Fe²⁺ in the serum， levels of TC， TG， FFA， MDA， Fe²⁺， and ROS in the liver， and protein levels of TFR1 and DMT1 in the liver （P<0.01）， and decreases in the activities of SOD， GPX and the protein levels of Nrf2， SLC7A11， and GPX4 in the liver （P<0.05， P<0.01）. Meanwhile， the liver tissue in the model group presented steatosis， iron deposition， mitochondrial shrinkage， and blurred or swollen mitochondrial cristae. Compared with the model group， all doses of Danggui Shaoyaosan reduced the body weight， liver weight， liver index， levels or activities of TC， TG， ALT， AST， and Fe²⁺ in the serum， levels of TC， TG， FFA， MDA， Fe²⁺， and ROS in the liver， and protein levels of TFR1 and DMT1 in the liver （P<0.01）， while increasing the activities of SOD and GPX and the protein levels of Nrf2， SLC7A11， and GPX4 in the liver （P<0.01）. Furthermore， Danggui Shaoyaosan alleviated steatosis， iron deposition， and mitochondrial damage in the liver. ConclusionDanggui Shaoyaosan may inhibit lipid peroxidation and ferroptosis by activating the Nrf2/SLC7A11/GPX4 signaling pathway to treat NAFLD.

[摘 要] 目的：探讨白蛋白结合型紫杉醇联合PD-1抑制剂用于治疗一线化疗失败的骨与软组织肉瘤的疗效及安全性。方法：回顾性分析北京积水潭医院骨肿瘤科2017年8月至2020年8月收治的一线化疗失败的晚期骨与软组织肉瘤患者。患者接受白蛋白结合型紫杉醇（125~140 mg/m2，第1天和第8天）与PD-1抑制剂（信迪利单抗或特瑞普利单抗，每21 d一次）联合治疗。每2个治疗周期评估1次疗效，按RECIST 1.1标准评估肿瘤疗效，按NCI-CTCAE5.0标准评估不良反应。结果：共20名患者纳入研究，完成1至8个治疗周期，中位治疗周期数为3个。所有患者均可评估疗效，完全缓解4例（20%），部分缓解0例，稳定9例（45%），疾病进展7例（35%）。客观缓解率（ORR）为20%，疾病控制率（DCR）为65%。中位无进展生存期（PFS）为3.0个月。治疗期间主要不良反应包括2级白细胞减少（40%）、1-2级神经毒性反应（20%），以及2级甲状腺功能减退（10%）。结论：白蛋白结合型紫杉醇联合PD-1抑制剂治疗为一线化疗失败的晚期骨与软组织肉瘤患者提供了一种潜在的治疗选择，其不良反应可控，值得开展更大样本的前瞻性研究进一步验证其疗效。

Objective: To confirm the therapeutic efficacy of the ginkgo biloba extract EGb761 on ischemic stroke and elucidate its underlying mechanism. Methods: Male Sprague-Dawley rats were divided into three groups: sham, model, and EGb761 (ginkgo biloba extract). Ischemic stroke was then simulated in rats via embolic middle cerebral artery occlusion surgery, with the extract administered half an hour before surgery. Neurological deficit scores, infarct volume, cerebral edema rate, and inflammatory factors served as the primary metrics for drug efficacy. Serum metabolites were analyzed using 1H-nuclear magnetic resonance to elucidate the operative mechanism. Results: Treatment with the ginkgo biloba extract EGb761 significantly ameliorated the neurological deficit scores (P = .0343), diminished the cerebral infarct volume (P = .0001) and cerebral edema rate (P = .0030), and alleviated neuroinflammation (all P < .05) in middle cerebral artery occlusion rats. In addition, it significantly altered the contents of various metabolites, such as 2-hydroxybutyrate, isoleucine, isopropanol, isobutyric acid, N6-acetyllysine, glutamate, glutamine, methionine, and N,N-dimethylglycine (all P < .05). Enrichment analysis of the differential metabolites indicated that EGb761 may be involved in the regulation of amino acid metabolism, betaine metabolism, glucose-alanine cycle, Warburg effect, and urea cycle. Conclusion The ginkgo biloba extract EGb761 demonstrates anti-ischemic stroke effect on ischemic stroke model rats by regulating amino acids and amino acid derivatives, such as isoleucine, N6-acetyllysine, glutamate, methionine, and N,N-dimethylglycine.

Objective:To compare the efficacy of different doses of tranexamic acid (TXA) for traumatic hemorrhagic shock (THS) in the early phase of trauma following acute exposure to high altitude in rabbits.Methods:Twenty-five healthy male New Zealand rabbits were randomly divided into plain control group ( n=5) and acute high-altitude THS group ( n=20) according to the random number table method. The plain control group did not undergo THS modeling throughout the experiment while the acute high-altitude THS group was raised in a hypoxia simulation chamber with a volume fraction of 10% for 3 days to establish the THS model. Based on the different doses of TXA administered intravenously at 30 minutes after THS modeling, the acute high-altitude THS group was further divided into four subgroups: acute high-altitude THS+0 mg/kg TXA subgroup, acute high-altitude THS+45 mg/kg TXA subgroup, acute high-altitude THS+90 mg/kg TXA subgroup and acute high-altitude THS+135 mg/kg TXA subgroup, with 5 rabbits in each. The vital signs [mean arterial pressure (MAP), heart rate, rectal temperature] and blood cell counts [red blood cell count (RBC), platelet count (PLT)], 4 coagulation parameters [fibrinogen (FIB), D-dimer, activated partial thromboplastin time (APTT), prothrombin time (PT)], thromboelastography [clotting reaction time (R value), clot formation time (K value), maximum amplitude (MA value)], syndecan-1, inflammatory factors [interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α)], and plasminogen activator inhibitor-1 (PAI-1) were recorded before blood loss, at 30 minutes and 120 minutes after blood loss. At 6 hours after THS, the lungs, terminal ileum, and kidneys of the rabbits were collected to observe tissue damage, and the wet/dry weight ratio (W/D) and total water content (TLW) of the lung tissue were measured. Results:(1) Vital signs: Before blood loss, there were no significant differences in MAP, heart rate, or rectal temperature between the acute high-altitude THS subgroups and the plain control group ( P>0.05). At 30 minutes and 120 minutes after blood loss, the acute high-altitude THS subgroups exhibited significantly lower MAP, heart rate, and rectal temperature compared to those in the plain control group ( P<0.05). No significant differences were observed in MAP, heart rate or rectal temperature among the acute high-altitude THS subgroups at any time point ( P>0.05). In the acute high-altitude THS subgroups, MAP, heart rate and rectal temperature were significantly decreased at 30 minutes and 120 minutes after blood loss compared to those before blood loss ( P<0.05); At 120 minutes after blood loss, these parameters were further significantly decreased compared to those at 30 minutes after blood loss ( P<0.05). (2) Blood cell counts: Before blood loss, the RBC count was significantly higher in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while the PLT was significantly lower ( P<0.05). At 30 minutes after blood loss, there was no significant difference in RBC count between the acute high-altitude THS subgroups and the plain control group ( P>0.05), but the PLT remained significantly lower in the acute high-altitude THS subgroups ( P<0.05). At 120 minutes after blood loss, the RBC count was significantly lower in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), with no significant differences among the acute high-altitude THS subgroups ( P>0.05). The PLT count was significantly lower in the acute high-altitude THS+0 mg/kg TXA subgroup compared to the other subgroups ( P<0.05). The PLT count in the acute high-altitude THS+45 mg/kg TXA subgroup was significantly lower than those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P<0.05), with no significant differences between the latter two subgroups ( P>0.05). (3) Four Coagulation parameters: Before blood loss, D-dimer level was significantly higher in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while no significant difference was observed in FIB ( P>0.05). APTT and PT were significantly shortened in the acute high-altitude THS subgroups ( P<0.05). At 30 minutes after blood loss, D-dimer level remained significantly higher in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while FIB was significantly lower ( P<0.05), with significant increase of APTT and PT compared to those before blood loss ( P<0.05). At 120 minutes after blood loss, the acute high-altitude THS+0 mg/kg TXA subgroup exhibited significantly higher D-dimer level compared to the other subgroups ( P<0.05), with significantly lower FIB and higher APTT and PT ( P<0.05). The acute high-altitude THS+45 mg/kg TXA subgroup also showed significantly higher D-dimer level compared to those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P<0.05), with significantly lower FIB and increased APTT and PT ( P<0.05). No significant differences were observed in D-dimer, FIB, APTT or PT between the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P>0.05). (4) Thromboelastography parameters: Before blood loss, the R value was significantly shorter in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while no significant differences were observed in K value or MA value ( P>0.05). At 30 minutes after blood loss, both R value and K value were significantly shorter in the acute high-altitude THS subgroups compared to those in the plain control group ( P<0.05), with no significant differences in MA value ( P>0.05). At 120 minutes after blood loss, the acute high-altitude THS+0 mg/kg TXA subgroup exhibited significantly increased R value and K value compared to those in the other subgroups ( P<0.05), while MA value was significantly decreased ( P<0.05). The remaining acute high-altitude THS subgroups showed significant decrease of R value and K value compared to those in the plain control group ( P<0.05), while MA value was significantly lower ( P<0.05). The acute high-altitude THS+45 mg/kg TXA subgroup exhibited significantly lower R value and K value compared to those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P<0.05), with no significant differences in R value, K value and MA value between the later two groups ( P<0.05). (5) Changes in Syndecan-1, inflammatory factors and PAI-1: Before blood loss, syndecan-1 was significantly higher in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while no significant differences were observed in IL-6, TNF-α, or PAI-1 ( P>0.05). At 30 minutes after blood loss, syndecan-1, IL-6, TNF-α, and PAI-1 were significantly higher in the acute high-altitude THS subgroups compared to those in the plain control group ( P<0.05). At 120 minutes after blood loss, syndecan-1, IL-6, TNF-α, and PAI-1 were significantly higher in the acute high-altitude THS subgroups compared to those in the plain control group ( P<0.05). Among them, the acute high-altitude THS+0 mg/kg TXA group exhibited significantly higher levels of syndecan-1, IL-6, TNF-α, and PAI-1 compared to the other acute high-altitude THS subgroups ( P<0.05). The acute high-altitude THS+45 mg/kg TXA subgroup had significantly higher syndecan-1, IL-6, and TNF-α compared to those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P<0.05), with no significant difference in PAI-1 ( P>0.05). No significant differences were observed in syndecan-1, IL-6, TNF-α or PAI-1 between the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P>0.05). (6) Tissue injury: At 6 hours after THS, acute high-altitude THS+0 mg/kg TXA group exhibited significant interstitial thickening of the lung with extensive inflammatory cell infiltration, localized loss of intestinal brush border accompanied by cellular disruption, and marked structural disruption of renal corpuscles with focal cellular injury and necrosis. At 6 hours after THS, the acute high-altitude THS+0 mg/kg TXA subgroup exhibited significantly higher lung injury scores, Chiu′s intestinal injury scores, and kidney injury scores compared to those of the other subgroups ( P<0.05). No significant differences were observed in the tissue injury scores of the lungs, intestines and kidneys among the other subgroups ( P>0.05). The acute high-altitude THS+0 mg/kg TXA subgroup also had significantly higher lung W/D and TLW compared to those in the other subgroups ( P<0.05). At 6 hours after THS, the acute high-altitude THS+45 mg/kg TXA group exhibited significantly higher W/D and TLW of the lung tissues compared to those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA groups ( P<0.05), with no significant differences between the latter two subgroups ( P>0.05). Conclusions:At 3 days after acute exposure to high altitude, rabbits show a hypercoagulable state of the blood, accompanied by endothelial barrier dysfunction. At 30 minutes after the induction of acute high-altitude THS, a single slow intravenous bolus injection of TXA at doses of 90 mg/kg and 135 mg/kg is more effective in improving coagulation and fibrinolysis function, inflammatory response, endothelial injury, and reduced the risk of pulmonary edema than that at a dose of 45 mg/kg.

Objective To investigate the relationship between clinical efficacy and lymphocyte subset variation in the treatment of middle and late stage hepatocellular carcinoma(HCC)undergoing initial transarterial chemoembolization(TACE).Methods A retrospective analysis was conducted on the clinical data of 33 patients with middle and late stage HCC who received initial TACE treatment.Lymphocyte subsets were measured before treatment and one month after treatment.Short-term efficacy was evaluated based on the modified response evaluation criteria in solid tumors(mRECIST),and then the patients were divided into remission group[18 cases,including complete remission(CR)and partial remission(PR)]and non-remission group[15 cases,including stable disease(SD)and progressive disease(PD)].The characteristics of lymphocyte subset variation characteristics before and after treatment were compared between the two groups.Results In the remission group,the absolute count and percentage of CD8+cells significantly increased,while the CD4/CD8 ratio and the percentage of CD19+cells significantly decreased after treatment(P＜0.05).Conversely,in the non-remission group,the percentage of CD8+cells significantly decreased,while the CD4/CD8 ratio and the percentage of CD19+cells significantly increased after treatment(P＜0.05).Significant differences were observed between the two groups in the changes of CD8+cells percentage,CD4/CD8 ratio,and CD19+cells percentage before and after treatment(P＜0.05).Conclusion The CD8+cells percentage,CD4/CD8 ratio,and CD19+cells percentage may serve as potential molecular markers for predicting treatment outcomes in HCC patients undergoing TACE.A decrease in the CD8+cells percentage accompanied by an increase in the CD4/CD8 ratio and CD19+cells percentage after the initial TACE treatment may indicate poor therapeutic outcomes.Timely adjustment of individualized treatment plans is recommended to improve patient prognosis.

Objective To evaluate the safety and feasibility of percutaneous mitral balloon valvuloplasty with the assistance of arterio-venous circuit.Methods From January 2015 to October 2022,a total 25 patients[19 females,6 males;age(61.60±9.00)years]were included,who were diagnosed with rheumatic heart disease and severe mitral stenosis.A transseptal puncture was performed to establish a femoral arterio-venous circuit,followed by graded dilation with Inoue balloon(diameters:22.00 mm to 28.00 mm).The target was a mitral valve area≥1.50 cm2 with mild or less regurgitation.Results The arterio-venous circuit was established,and mitral balloon valvuloplasty was successfully completed in all 25 patients.Among them,20 patients experienced difficulty with transvalvular crossing using the balloon catheter with conventional methods,16 patients had valvular severe calcification,and 3 patients presented with a left atrial appendage thrombus despite of more than 6-month anticoagulation therapy with warfarin.The mean balloon diameter was(25.00±1.40)mm.The mitral valve area increased from(0.91±0.15)cm2 preoperatively to(1.70±0.14)cm2 postoperatively(P＜0.001).Mean left atrial pressure decreased from(27.00±7.50)mmHg to(16.36±4.07)mmHg(P＜0.001),and mean pulmonary artery pressure decreased from(40.84±13.81)mmHg to(25.00±7.12)mmHg(P＜0.001).All patients showed significant symptom improvement with no complications.Conclusions Arterio-venous circuit for percutaneous mitral balloon valvuloplasty is safe and feasible.This technique can serve as an alternative to standard technique for patients with complex mitral stenosis.

Objective:To investigate the relationship between peripheral blood amyloid protein A(SAA),C-reactive protein(CRP)/prealbumin(PA),vascular endothelial growth factor(VEGF)and the severity,pulmonary function,and prognosis of children with Mycoplasma pneumoniae pneumonia(MPP).Methods:106 children with MPP who were admitted to Huichang County Maternal and Child Health Hospital of Ganzhou from February 2023 to August 2024 were selected as the study subjects(MPP group),they were divided into good prognosis group(n=77)and poor prognosis group(n=29)according to the 28 days prognosis,they were divided into mild group(n=61)and severe group(n=45)according to the disease severity.Another 90 healthy children who underwent physical examinations during the same period were selected as the control group.The peripheral blood SAA,CRP/PA,VEGF,and pulmonary function indicators between the control group and MPP group were compared,and the peripheral blood SAA,CRP/PA,and VEGF levels between the mild group and severe group were compared,Pearson and Spearman correlation analysis was used to investigate the correlation between peripheral blood SAA,CRP/PA,VEGF and pulmonary function indicators and disease severity in children with MPP.The levels of peripheral blood SAA,CRP/PA,and VEGF between poor prognosis group and good prognosis group were compared.Receiver operating characteristic(ROC)curve was used to analyze the value of peripheral blood SAA,CRP/PA,VEGF detection alone and in combination for evaluating the 28 days prognosis in children with MPP.Results:The peripheral blood SAA,CRP/PA,and VEGF levels in the MPP group were higher than those in the control group,while the forced expiratory volume in one second(FEV1),peak expiratory flow(PEF),and forced vital capacity(FVC)were lower than those in the control group(P＜0.05).Peripheral blood SAA,CRP/PA,and VEGF levels in the severe group were higher than those in the mild group(P＜0.05).Peripheral blood SAA,CRP/PA,VEGF were negatively correlated with FEV1,PEF,FVC,but positively correlated with the severity of the disease(P＜0.05).Peripheral blood SAA,CRP/PA,and VEGF in the poor prognosis group were higher than those in the good prognosis group(P＜0.05).The area under the curve(AUC)values of peripheral blood SAA,CRP/PA,and VEGF for evaluating the 28 days prognosis of MPP patients were 0.514,0.562,and 0.585,respectively,the AUC of 28 days prognosis evaluation in children with MPP by combined detection of peripheral blood SAA,CRP/PA,and VEGF was 0.725,significantly higher than that of individual detection.Conclusion:Abnormal elevation of peripheral blood SAA,CRP/PA,and VEGF levels is involved in the progression of MPP,the injury of pulmonary function,and poor prognosis.combined detection of peripheral blood SAA,CRP/PA,and VEGF levels can effectively evaluate the short-term prognosis of MPP patients.

Objective:To explore the clinical efficacy of Shexiang Baoxin pill in patients with unstable angina pectoris(UAP)and type 2 diabetes mellitus(T2DM)using meta-analysis.Methods:We searched the databases including Pubmed,Web of Science,EMbase,EBSCO,Cochrane,CBM,CNKI and Wanfang for randomized controlled trials(RCTs)about the therapeutic effect of Shexiang Baoxin pill on patients with UAP and T2DM from the establish-ment to January 20th,2023.RevMan 5.3 software was used to perform meta-analysis to investigate the effect of Shexiang Baoxin pill on angina improvement and blood glucose fluctuation in patients with UAP and T2DM.Results:Six eligible literatures were included,including 346 patients in Shexiang Baoxin pill group and control group respec-tively.The results of meta-analysis showed that compared to participants in control group,those in Shexiang Baox-in pill group had significantly higher clinical overall efficiency(OR=3.13,95％CI 2.01～4.89,P＜0.001),and significantly lower angina attack frequency(MD=-0.66,95％CI-0.79～-0.52,P＜0.001),duration of angi-na(MD=-3.10,95％CI-4.11～-2.09,P＜0.001),and 2-hour postprandial blood glucose(MD=-1.79,95％CI-2.00～-1.57,P＜0.001).Conclusion:Shexiang Baoxin pill could improve clinical overall efficiency,an-gina attack frequency and duration,and reduce 2-hour postprandial blood glucose in patients with unstable angina pectoris and type 2 diabetes mellitus.

Objective:To compare the efficacy of different doses of tranexamic acid (TXA) for traumatic hemorrhagic shock (THS) in the early phase of trauma following acute exposure to high altitude in rabbits.Methods:Twenty-five healthy male New Zealand rabbits were randomly divided into plain control group ( n=5) and acute high-altitude THS group ( n=20) according to the random number table method. The plain control group did not undergo THS modeling throughout the experiment while the acute high-altitude THS group was raised in a hypoxia simulation chamber with a volume fraction of 10% for 3 days to establish the THS model. Based on the different doses of TXA administered intravenously at 30 minutes after THS modeling, the acute high-altitude THS group was further divided into four subgroups: acute high-altitude THS+0 mg/kg TXA subgroup, acute high-altitude THS+45 mg/kg TXA subgroup, acute high-altitude THS+90 mg/kg TXA subgroup and acute high-altitude THS+135 mg/kg TXA subgroup, with 5 rabbits in each. The vital signs [mean arterial pressure (MAP), heart rate, rectal temperature] and blood cell counts [red blood cell count (RBC), platelet count (PLT)], 4 coagulation parameters [fibrinogen (FIB), D-dimer, activated partial thromboplastin time (APTT), prothrombin time (PT)], thromboelastography [clotting reaction time (R value), clot formation time (K value), maximum amplitude (MA value)], syndecan-1, inflammatory factors [interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α)], and plasminogen activator inhibitor-1 (PAI-1) were recorded before blood loss, at 30 minutes and 120 minutes after blood loss. At 6 hours after THS, the lungs, terminal ileum, and kidneys of the rabbits were collected to observe tissue damage, and the wet/dry weight ratio (W/D) and total water content (TLW) of the lung tissue were measured. Results:(1) Vital signs: Before blood loss, there were no significant differences in MAP, heart rate, or rectal temperature between the acute high-altitude THS subgroups and the plain control group ( P>0.05). At 30 minutes and 120 minutes after blood loss, the acute high-altitude THS subgroups exhibited significantly lower MAP, heart rate, and rectal temperature compared to those in the plain control group ( P<0.05). No significant differences were observed in MAP, heart rate or rectal temperature among the acute high-altitude THS subgroups at any time point ( P>0.05). In the acute high-altitude THS subgroups, MAP, heart rate and rectal temperature were significantly decreased at 30 minutes and 120 minutes after blood loss compared to those before blood loss ( P<0.05); At 120 minutes after blood loss, these parameters were further significantly decreased compared to those at 30 minutes after blood loss ( P<0.05). (2) Blood cell counts: Before blood loss, the RBC count was significantly higher in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while the PLT was significantly lower ( P<0.05). At 30 minutes after blood loss, there was no significant difference in RBC count between the acute high-altitude THS subgroups and the plain control group ( P>0.05), but the PLT remained significantly lower in the acute high-altitude THS subgroups ( P<0.05). At 120 minutes after blood loss, the RBC count was significantly lower in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), with no significant differences among the acute high-altitude THS subgroups ( P>0.05). The PLT count was significantly lower in the acute high-altitude THS+0 mg/kg TXA subgroup compared to the other subgroups ( P<0.05). The PLT count in the acute high-altitude THS+45 mg/kg TXA subgroup was significantly lower than those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P<0.05), with no significant differences between the latter two subgroups ( P>0.05). (3) Four Coagulation parameters: Before blood loss, D-dimer level was significantly higher in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while no significant difference was observed in FIB ( P>0.05). APTT and PT were significantly shortened in the acute high-altitude THS subgroups ( P<0.05). At 30 minutes after blood loss, D-dimer level remained significantly higher in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while FIB was significantly lower ( P<0.05), with significant increase of APTT and PT compared to those before blood loss ( P<0.05). At 120 minutes after blood loss, the acute high-altitude THS+0 mg/kg TXA subgroup exhibited significantly higher D-dimer level compared to the other subgroups ( P<0.05), with significantly lower FIB and higher APTT and PT ( P<0.05). The acute high-altitude THS+45 mg/kg TXA subgroup also showed significantly higher D-dimer level compared to those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P<0.05), with significantly lower FIB and increased APTT and PT ( P<0.05). No significant differences were observed in D-dimer, FIB, APTT or PT between the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P>0.05). (4) Thromboelastography parameters: Before blood loss, the R value was significantly shorter in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while no significant differences were observed in K value or MA value ( P>0.05). At 30 minutes after blood loss, both R value and K value were significantly shorter in the acute high-altitude THS subgroups compared to those in the plain control group ( P<0.05), with no significant differences in MA value ( P>0.05). At 120 minutes after blood loss, the acute high-altitude THS+0 mg/kg TXA subgroup exhibited significantly increased R value and K value compared to those in the other subgroups ( P<0.05), while MA value was significantly decreased ( P<0.05). The remaining acute high-altitude THS subgroups showed significant decrease of R value and K value compared to those in the plain control group ( P<0.05), while MA value was significantly lower ( P<0.05). The acute high-altitude THS+45 mg/kg TXA subgroup exhibited significantly lower R value and K value compared to those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P<0.05), with no significant differences in R value, K value and MA value between the later two groups ( P<0.05). (5) Changes in Syndecan-1, inflammatory factors and PAI-1: Before blood loss, syndecan-1 was significantly higher in the acute high-altitude THS subgroups compared to that in the plain control group ( P<0.05), while no significant differences were observed in IL-6, TNF-α, or PAI-1 ( P>0.05). At 30 minutes after blood loss, syndecan-1, IL-6, TNF-α, and PAI-1 were significantly higher in the acute high-altitude THS subgroups compared to those in the plain control group ( P<0.05). At 120 minutes after blood loss, syndecan-1, IL-6, TNF-α, and PAI-1 were significantly higher in the acute high-altitude THS subgroups compared to those in the plain control group ( P<0.05). Among them, the acute high-altitude THS+0 mg/kg TXA group exhibited significantly higher levels of syndecan-1, IL-6, TNF-α, and PAI-1 compared to the other acute high-altitude THS subgroups ( P<0.05). The acute high-altitude THS+45 mg/kg TXA subgroup had significantly higher syndecan-1, IL-6, and TNF-α compared to those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P<0.05), with no significant difference in PAI-1 ( P>0.05). No significant differences were observed in syndecan-1, IL-6, TNF-α or PAI-1 between the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA subgroups ( P>0.05). (6) Tissue injury: At 6 hours after THS, acute high-altitude THS+0 mg/kg TXA group exhibited significant interstitial thickening of the lung with extensive inflammatory cell infiltration, localized loss of intestinal brush border accompanied by cellular disruption, and marked structural disruption of renal corpuscles with focal cellular injury and necrosis. At 6 hours after THS, the acute high-altitude THS+0 mg/kg TXA subgroup exhibited significantly higher lung injury scores, Chiu′s intestinal injury scores, and kidney injury scores compared to those of the other subgroups ( P<0.05). No significant differences were observed in the tissue injury scores of the lungs, intestines and kidneys among the other subgroups ( P>0.05). The acute high-altitude THS+0 mg/kg TXA subgroup also had significantly higher lung W/D and TLW compared to those in the other subgroups ( P<0.05). At 6 hours after THS, the acute high-altitude THS+45 mg/kg TXA group exhibited significantly higher W/D and TLW of the lung tissues compared to those in the acute high-altitude THS+90 mg/kg TXA and acute high-altitude THS+135 mg/kg TXA groups ( P<0.05), with no significant differences between the latter two subgroups ( P>0.05). Conclusions:At 3 days after acute exposure to high altitude, rabbits show a hypercoagulable state of the blood, accompanied by endothelial barrier dysfunction. At 30 minutes after the induction of acute high-altitude THS, a single slow intravenous bolus injection of TXA at doses of 90 mg/kg and 135 mg/kg is more effective in improving coagulation and fibrinolysis function, inflammatory response, endothelial injury, and reduced the risk of pulmonary edema than that at a dose of 45 mg/kg.

Enhancer of zeste homolog 2(EZH2)is a histone methyltransferase It mediates trimethylation of lysine 27 on histone H3,thereby facilitating the epigenetic silencing of downstream genes.In conjunc-tion with SUZ12,EED,and other components,it constitutes the polycomb repressive complex 2(PRC2)complex.While EZH2 is intricately involved in cellular proliferation and cardiac development,the chan-ges in its expression during cardiac terminal differentiation remain elusive.In this study,we employed differential gene expression analysis of embryonic and adult myocardial cells using the GEO database,and found that EZH2 is highly expressed in embryonic myocardium,but is present at very low levels in adult myocardium(P＜0.0001).Conversely,the expression changes of PRC2 members SUZ12 and EED are not as pronounced.Online analysis through the Tabula Muris database indicates that under physiological conditions,various cell subpopulations in the adult mouse heart exhibit negligible expression of EZH2.Immunohistochemical staining of mouse cardiac tissues shows that EZH2 is highly expressed in embryonic and neonatal myocardium but declines progressively from the first day after birth(P＜0.0001),becoming almost undetectable by the third day.Western blotting further confirms the rapid disappearance of EZH2 expression post-birth(P＜0.05),with EZH1 compensating for the downregulation of EZH2 to maintain H3K27me3 modification levels.Additionally,using the P19 teratocarcinoma stem cell model for cardio-myocyte differentiation,it is observed that EZH2 is significantly upregulated during the transition from cardiac progenitor cells to spontaneously beating cardiomyocytes,correlating with the expression of the cardiomyocyte transcription factor Gata4(P＜0.01).Targeted degradation of EZH2 using the small mole-cule drug MS1943 significantly inhibits the proliferation of induced cardiomyocytes,as evidenced by 5-e-thynyl-2'-deoxyuridine(EdU)incorporation assays(P＜0.01),and RT-qPCR reveals a marked in-crease in the expression of the proliferation inhibitor CDKN1A(P＜0.01).In summary,the high expres-sion of EZH2 in embryonic myocardial cells is associated with enhanced cell proliferation.The rapid loss of EZH2 expression postnatally correlates with the loss of proliferative capacity in cardiomyocytes,mark-ing it as a key indicator of cardiac terminal differentiation.