Cells and exosomes derived from them are extensively used as biological carrier systems. Cells demonstrate superior targeting specificity and prolonged circulation facilitated by their rich array of surface proteins, while exosomes, due to their small size, cross barriers and penetrate tumors efficiently. However, challenges remain, cells' large size restricts tissue penetration, and exosomes have limited targeting accuracy and short circulation times. To address these challenges, we developed a novel concept termed exosomal spheres. This approach involved incorporating platelet-derived exosomes shielded with phosphatidylserine (PS) and linked via pH-sensitive bonds for drug delivery applications. The study demonstrated that, compared with exosomes, the exosomal spheres improved blood circulation through the upregulation of CD47 expression and shielding of phosphatidylserine, thereby minimizing immune clearance. Moreover, the increased expression of P-selectin promoted adhesion to circulating tumor cells, thereby enhancing targeting efficiency. Upon reaching the tumor site, the hydrazone bonds of exosome spheres were protonated in the acidic tumor microenvironment, leading to disintegration into uniform-sized exosomes capable of deeper tumor penetration compared to platelets. These findings suggested that exosome spheres addressed the challenges and offered significant potential for efficient and precise drug delivery.

Objective:To analyze the efficacy of endovascular treatment for venous outflow tract obstruction after liver transplantation.Methods:A retrospective analysis was conducted on the data of 7 patients with venous outflow tract obstruction after liver transplantation admitted to Beijing Friendship Hospital, Capital Medical University from November 2020 to December 2024. Among them, there were 5 males and 2 females, with the age of (22.3±8.1) years. The primary diseases included 2 cases of Budd-Chiari syndrome, 1 case of hepatic veno-occlusive disease, 1 case of portal veno-hepatic sinus vascular disease, 1 case of ornithine carbamoyltransferase deficiency, 1 case of primary biliary cirrhosis, and 1 case of autoimmune cirrhosis. Analyze the patient's clinical manifestations, obstruction of venous outflow tract, hemoglobin levels within one week before and one week after the operation, endovascular treatment conditions, and intraoperative complications such as abdominal hemorrhage and vascular injury. Ultrasound was used to measure the depth of ascites and pleural effusion. All patients were followed up immediately after the operation through phone calls or follow-up visits. The clinical symptoms, abdominal vascular ultrasound, enhanced CT and survival status of the patients were followed up.Results:All 7 patients were diagnosed with venous outflow tract obstruction by intraoperative angiography, including 1 cases of inferior vena cava obstruction, 2 cases of hepatic vein obstruction, and 4 cases of vena cava combined with hepatic vein obstruction. A total of 12 endovascular treatments were performed on 7 patients. Among them, 4 patients received balloon dilation and angioplasty once, 1 patient received balloon dilation and angioplasty twice, 1 patient underwent hepatic vein stent implantation after 2 hepatic vein balloon dilation and angioplasty, and 1 patient underwent intrahepatic portosystemic shunt via jugular vein after 2 hepatic vein balloon dilation and angioplasty. The abdominal distensionof the patients were all relieved after the operation, the ascites and pleural effusion decreased, and the edema symptoms of the lower extremities disappeared. There were no intraoperative complications. The preoperative hemoglobin of 7 patients was (113.4±34.0) g/L, and the postoperative hemoglobin was (126.6±34.8) g/L, which increased significantly compared with that before the operation, and the difference was statistically significant ( t=-0.71, P=0.038). Seven patients were followed up for 6 to 24 months, with a median of 12 months. None of them had obvious symptoms including abdominal distension. Abdominal ultrasound and CT indicated that the blood flow of the transplanted liver was unobstructed, and no patient died. Conclusion:Venous outflow tract obstruction after liver transplantation can cause severe symptoms. Endovascular treatment is an effective treatment for venous outflow tract obstruction after liver transplantation.

Objective To explore the feasibility of phase-contrast CT for three-dimensional visualization of in vitro intrahepatic vessels and necrotic foci in mouse model of acute liver injury(ALI).Methods Six clean grade male wild-type C57BL/6 mice were randomly divided into model group and control group(each n=3).The mice in model group were fed with overdose of acetaminophen to induce ALI,while those in control group were fed with the same amount of distilled water.After 24 h,the mice were all sacrificed,the livers were harvested and then fixed and dehydrated.Phase-contrast CT images of in vitro liver were acquired,sectional and three-dimensional images were reconstructed.The effect of phase-contrast CT for displaying the outline of liver and internal vessels and necrotic foci were observed,the maximum diameter and volume of necrotic foci were quantitatively analyzed,and the results of phase-contrast CT were compared with pathological findings.Results The original projection and sectional images of phase-contrast CT clearly showed the outline of in vitro liver and internal vasculatures.Necrotic foci within the liver were found in model group,but not in control group.The findings of phase-contrast CT corresponded accurately to those of pathology.Three-dimensional reconstruction images of phase-contrast CT clearly displayed intrahepatic portal vein system and hepatic vein system in both groups,and discontinuous punctate necrotic foci within the liver were found in model group,mainly distributed around hepatic vein,with a median maximum diameter of 18.50 μm and a median volume of 5 870.11 μm3,but was not observed in control group.Conclusion Phase-contrast CT could be used in three-dimensional visualization of intrahepatic vessels and necrotic foci of in vitro liver in mouse model of ALI.

Objective To explore the feasibility,safety and effectiveness of ultrasound-guided biopsy of pancreatic lesions with exophytic and backward growth morphology.Methods Fifty-three patients with pancreatic lesions with exophytic and backward growth morphology who underwent ultrasound-guided biopsy were retrospectively collected.Conventional ultrasonic manifestations of lesions were observed,and the technical success rate,complication rate,repeat puncture rate,as well as the sensitivity,specificity and accuracy of biopsy were recorded.Results Totally 61 lesions were detected,with the maximum diameter of 1.4-7.3 cm and the median maximum diameter of 2.7 cm,located in pancreatic uncinate process(26/61,42.62％),head(12/61,19.67％),neck(13/61,21.31％)and body(10/61,42.62％),respectively,mainly presented as hypoechogenic(61/61,100％)and borderless(60/61,98.36％)masses tending to invade blood vessels(51/61,83.61％)and pancreatic ducts(40/61,65.57％).The technical success rate,complication rate and repeat puncture rate of ultrasound-guided biopsy was 100％(61/61),1.89％(1/53)and 21.31％(13/61),respectively,and the sensitivity,specificity and accuracy of biopsy diagnosis was 75.00％(45/60),100％(1/1)and 75.41％(46/61),respectively.Conclusion Ultrasound-guided biopsy was safe and feasible for pancreatic lesions with exophytic and backward growth morphology,but its diagnostic efficacy should be improved.

Objective To analyze the focus and shortcomings of provincial-level digitalization policies for Traditional Chinese Medicine(TCM),and to provide references for improving relevant policies.Methods A three-dimensional analytical framework—comprising"digitalization policy coverage-economic level-TCM development level"was constructed to quantitatively analyze provincial TCM digitalization policy documents issued over the past five years.Results A total of 750 policy items were extracted.Among them,digital applications accounted for the largest proportion(58.13%),while digital governance(26.53%)and digital infrastructure(15.33%)were relatively less emphasized.Two-dimensional analysis revealed that 48.4%of provinces had both low economic levels and low digital policy coverage,while 45.2%had both low TCM development levels and low policy coverage.Multiple linear regression result showed a positive association between digitalization policies coverage and TCM development level,with no significant correlation to economic level.Conclusion Most provincial TCM digitalization policies prioritize application while neglecting governance and infrastructure.There is a need to strengthen talent development and standard system construction,The extent of policy coverage is closely related to the level of TCM development,indicating the need to enhance top-level policy design,Provincial policies vary in focus and can be categorized into three types:industry-driven,technology-driven,and demand-driven.

Objective:To investigate the role of dynamic changes in liver stiffness measurement (LSM) in predicting liver-related end-point events (LREs) occurrence in patients with chronic hepatitis B (CHB) with liver fibrosis during long-term antiviral therapy.Methods:Data were collected from CHB patients whose liver biopsy results showed Metavir fibrosis stage F2～F4 or clinically diagnosed cirrhosis. Entecavir antiviral therapy was mainly administered. Follow-up was conducted once every six months. Clinical data such as demographic information, blood routine tests, liver biochemical parameters, HBV virological and serological test results, and LSM were collected. Dynamic changes in LSM were categorized into four types based on LSM levels before treatment (0y) and following two years of antiviral therapy (2y) : (1) LSM 0y < 10 kPa and LSM 2y < 10 kPa, i.e., LSM persisted < 10 kPa; (2) LSM 0y < 10 kPa and LSM 2y ≥ 10 kPa, i.e., LSM increased to ≥ 10 kPa; (3) LSM 0y ≥ 10 kPa and LSM 2y < 10 kPa, i.e., LSM decreased to < 10 kPa; (4) LSM 0y ≥ 10 kPa and LSM 2y ≥ 10 kPa, i.e., LSM persisted ≥ 10 kPa. The predictive role of the dynamic changes of LSM in the occurrence of LREs was analyzed. The Wilcoxon rank-sum test was used for quantitative data. Fisher's exact test was used for categorical data. Multivariate analysis was performed using the Cox proportional hazards regression model. Survival curves were plotted and compared using the Kaplan-Meier. Results:A total of 713 CHB cases with liver fibrosis were included, among whom 512 had cirrhosis. The cumulative incidence of LREs following two years of antiviral therapy was low in patients with LSM 0y < 10 kPa during follow-up (all patients: LSM persisted < 10 kPa 1.6% vs. LSM increased to ≥ 10 kPa 0%; cirrhosis subgroup: LSM persisted < 10 kPa 0% vs. LSM increased to ≥ 10 kPa 0%). The 5-year cumulative incidence of LREs following two years of antiviral treatment was significantly higher in patients with LSM0y ≥ 10 kPa than in those with LSM persisting ≥ 10 kPa and those with LSM decreasing to < 10 kPa during follow-up (all patients: LSM persisted ≥ 10 kPa 12.4% vs. LSM decreased to < 10 kPa 3.6%; cirrhosis subgroup: LSM persisted ≥ 10 kPa 12.6% vs. LSM decreased to < 10 kPa 4.3%). Patients with LSM persisting at ≥ 10 kPa had a significantly increased risk of LREs following two years of antiviral treatment compared with those whose LSM decreased to <10 kPa during follow-up after adjusting for age, gender, baseline body mass index, platelet count, and alanine aminotransferase (all patients, aHR=2.96, 95% CI: 1.41～6.24, P=0.005; cirrhosis subgroup, aHR=2.74, 95% CI:1.26～5.95, P=0.011). Conclusions:LSM<10 kPa before antiviral treatment had a lower risk of liver-related endpoint events following two years of treatment among CHB patients with liver fibrosis. LSM ≥10 kPa before antiviral treatment and LSM persisted ≥10 kPa two years following treatment had a significantly higher occurrence risk of liver-related endpoints than LSM<10 kPa following treatment among CHB patients with liver fibrosis.

Objective:To dynamically assess liver fibrosis using magnetic resonance elastography (MRE) and explore factors associated with fibrosis reversal in patients with metabolic dysfunction-associated steatohepatitis (MASH).Methods:This study included data from patients diagnosed with MASH by liver biopsy who underwent at least two MRE examinations. Patients were divided into a fibrosis reversal group and a non-reversal group according to whether MRE values decreased by 20% during follow-up. Differences in clinical data between the groups were compared using analysis of variance, the Kruskal-Wallis test, and the chi-square test. Univariate and multivariate logistic regression analyses were used to explore independent risk factors for fibrosis reversal in MASH.Results:A total of 46 cases were included in this study (mean age 50.1±12.3 years, BMI 26.1±3.1 kg/m2). Among them, the reversal group accounted for 26.1%. The rate of decrease in MRI proton density fat fraction (PDFF) was significantly higher in the reversal group (-50.0% vs. -8.1%, P=0.001) than in the non-reversal group between the two MRE examinations. The reversal group showed a more significant change rate of decreases in fasting insulin (-37.3% vs. -3.6%, P=0.011), insulin resistance index (-38.6% vs. -6.5%, P=0.044), and ALP (-24.9% vs. 0, P=0.004). Multivariate logistic regression analysis indicated that the rate of change in MRI PDFF was an independent predictor of fibrosis reversal ( OR=0.96, 95% CI: 0.92-1.00, P=0.046). Conclusion:A decrease in MRI proton density fat fraction levels is independently associated with liver fibrosis reversal in MASH, suggesting that intervention targeting liver fat content may be an effective treatment strategy.

Objective To describe the clinical features of patients with primary sclerosing cholangitis(PSC)in China based on a nationwide multicenter patient cohort,and to investigate the risk factors for prognosis.Methods A retrospective cohort study was conducted among the patients with a confirmed diagnosis of PSC based on the electronic medical record system of seven grade A tertiary hospitals across the country,and related data were extracted.The Mann-Whitney U test was used for comparison of continuous data between groups,and the chi-square test was used for comparison of categorical data between groups.The Kaplan-Meier method was used to estimate liver transplant-free survival,and the log-rank test was used for comparison of survival rate between PSC patients with different features.The Cox regression model was used to identify independent risk factors for the prognosis of PSC patients and the interactions between key factors.Results A total of 107 patients were enrolled,among whom 55.6%(55/99)had large-duct PSC and 29.0%(31/107)had comorbidity with inflammatory bowel disease(IBD).The positivity rate of anti-neutrophil cytoplasmic antibody(ANCA)was 32.9%(24/73),and 50.0%(40/80)of the patients had an increase in IgG/IgM.The median symptom-to-diagnosis interval was 1 year(<1-4.0),and 38.3%(41/107)of the patients had progressed to decompensated cirrhosis at the time of diagnosis.The median liver transplant-free survival time was 114 months(95%confidence interval[CI]:62-166),with a 5-year survival rate of 65.7%.The multivariate analysis showed that an increase in total bile acid(TBA)(hazard ratio[HR]=1.006,95%CI:1.002-1.010,P=0.001)and a prolonged symptom-to-diagnosis interval(HR=1.252,95%CI:1.059-1.480,P=0.009)were independent risk factors for prognosis.The interaction analysis showed that compared with the female patients with TBA<50 μmol/L,both male and female patients with TBA≥50 μmol/L had a significant increase in the risk of liver transplantation or death(male:HR=16.563,95%CI:2.103-130.449,P<0.001;female:HR=17.009,95%CI:2.113-136.934,P<0.001),and compared with the patients with an age of<45 years and a TBA level of<50 μmol/L,the patients with an age of≥45 years and a TBA level of≥50 μmol/L had a significant increase in the risk of liver transplantation or death(HR=10.729,95%CI:1.325-86.859,P=0.026).Compared with the female patients with an symptom-to-diagnosis interval of≤2 years,the male patients with a symptom-to-diagnosis interval of>2 years had an increased risk of liver transplantation or death(HR=4.825,95%CI:1.725-13.644,P=0.003),and compared with the patients with an age of<45 years and a symptom-to-diagnosis interval of≤2 years,the patients with an age of<45 years and a symptom-to-diagnosis interval of>2 years had an increased risk of liver transplantation or death(HR=4.983,95%CI:1.366-18.173,P=0.015).Conclusion Compared with the reports from Western countries,large-duct PSC is also the main type of PSC in China,but with a relatively low proportion,and there is also a relatively low proportion of patients with IBD or positive ANCA.An increase in TBA and a prolonged symptom-to-diagnosis interval are independent risk factors for prognosis,with significant interactions with age and sex.This suggests that early screening and intervention should be enhanced to improve prognosis.

Objective To explore the relationship between pathogenic microorganism types,age and season in 2 188 children with respiratory tract infections.Methods A total of 2 188 children with respiratory tract in-fections admitted to the Department of Pediatrics,962 Hospital,Joint Logistic Support Force of PLA from June 2023 to May 2024 were selected as the study subjects.Targeted next generation sequencing(tNGS)tech-nology was used to detect 107 common pathogenic microorganism in children with respiratory tract infections,including Haemophilus influenzae,rhinovirus,Moraxella catarrhalis,Mycoplasma pneumoniae,Staphylococcus aureus,Streptococcus pneumoniae,human parainfluenza virus,human respiratory syncytial virus,etc.The re-spiratory tract infection situation and epidemiological characteristics of children in Harbin were analyzed.Re-sults Among 2 188 pediatric patients,98.5%(2 156/2 188)tested positive for pathogenic microorganism,with Haemophilus influenzae accounting for the highest proportion of 33.5%(732/2 188),followed by rhino-virus of 25.0%(547/2 188)and Moraxella catarrhalis of 24.8%(543/2 188).The positive rates of Hae-mophilus influenzae and human adenovirus in male children were higher than those in female children(P<0.05),while there were no statistically significant differences in the positive positive rates of other pathogenic microorganism between male and female children(P>0.05).Except for human adenovirus and influenza A virus,which showed no statistically significant differences in positive rates among different age groups(P>0.05),there were statistically significant differences in the positive rates of other pathogenic microorganism a-mong different age groups(P<0.05).The positive rates of pathogenic microorganism in preschool children were relatively high.There were no statistically significant differences in the positive rates of Streptococcus and Staphylococcus aureus in different seasons(P>0.05),while there were statistically significant differences in the positive rates of other pathogenic microorganism in different seasons(P<0.05).The positive rates of Haemophilus influenzae,Streptococcus pneumoniae,human metapneumovirus,human parainfluenza virus and SARS-Cov-2 were the highest in summer(P<0.05).Conclusion 2 188 children with respiratory tract infec-tions were mainly caused by pathogenic microorganism such as Haemophilus influenzae,rhinovirus,and Moraxella catarrhalis,etc.Preschool children is a susceptible group,and the prevalence of pathogenic microor-ganism varies seasonally.In clinical practice,relevant prevention and control measures should be developed based on this characteristic to reduce the incidence of diseases.

Objective The objective of this study was to investigate the effects of maytansine on proliferation,migration,in-vasion,apoptosis and autophagy of human thyroid cancer C643 cells.Methods C643 cells were treated with different concentrations(0.049,0.195,0.781,3.125,12.5,50 and 200 μmol/L)of maytansine,the effect of maytansine on the proliferation of C643 cells was detected by the sulforhodamine B(SRB)method,and the concentration of subsequent experiments was determined.C643 cells in the logarithmic growth stage period were divided into the control group,low-dose group,mid-dose group and high-dose group.The effects of maytansine on migration and invasion abilities of C643 cells were detected by cell scratch and Transwell chamber assay;The levels of reactive oxygen species(ROS)were detected by 2′,7′-dichlorofluorescein diacetate(DCFH-DA)fluorescent probe experi-ment;The apoptosis rate of C643 cells was detected by flow cytometry;The expression of proteins related to apoptosis or autophagy was detected by Western blot.Results Maytansine at concentrations of 0.049,0.195,0.781,3.125,12.5,50 and 200 μmol/L could in-hibit the proliferation of C643 cells(P<0.05),and exhibited a significant concentration time dependence.The half maximal inhibitory concentrations(IC50)at 24,48 and 72 h were 54.255,5.193 and 0.647 μmol/L,respectively;The cell scratch and Transwell chamber results showed that maytansine at concentrations of 0.1,1 and 10 μmol/L could reduce the migration and invasion abilities of C643 cells(P<0.05 and P<0.01).The fluorescence probe results showed that maytansine at concentrations of 0.1,1 and 10μmol/L could increase the intracellular ROS levels of C643 cells(P<0.01).The flow cytometry results showed that maytansine at concentrations of 0.1,1 and 10 μmol/L could concentration dependently increase the apoptosis rate of C643 cells(P<0.01).The Western blot results showed that with the increase of maytansine concentrations,the expression of Bax protein related to apoptosis in C643 cells increased(P<0.05),the expression of Bcl-2 decreased(P<0.05),the expression of LC3Ⅱ/Ⅰ(P<0.05)and Beclin-1(P<0.01)increased,while the expression of p62 decreased(P<0.001).Conclusion Maytansine can inhibit the proliferation,migration and invasion of human thyroid cancer C643 cells,and induce the synergistic effect on apoptosis and autophagy by increasing intracellular ROS levels.