[摘 要] 目的：开发新型溶瘤呼肠孤病毒（Reo）递送系统，以克服中和抗体对Reo的中和作用并提升其肿瘤靶向性。方法：通过切向流过滤联合超高速离心法制备自然杀伤细胞外泌体（NKexo），叶酸（FA）修饰后采用挤压法包载Reo，构建FA-NKexo-Reo递送系统；通过透射电镜（TEM）、纳米粒径分析、蛋白质印迹（WB）法、核磁共振氢谱及流式细胞术等技术表征其理化性质；采用CCK-8、流式细胞术、Transwell实验及激光共聚焦显微镜评估FA-NKexo-Reo递送系统体外细胞毒性及细胞摄取能力；通过人卵巢癌裸鼠皮下移植瘤模型评价FA-NKexo-Reo的肿瘤靶向性、疗效及安全性。结果：FA-NKexo-Reo粒径为（94.0 ± 28.5）nm，Zeta电位为（-21.26 ± 1.57）mV，包封率达（49.7 ± 15.6）%；在中和抗体的存在下，FA-NKexo-Reo对卵巢癌细胞SKOV3和A2780仍可表现出显著的细胞毒性（P < 0.01）；荷瘤鼠活体成像显示FA-NKexo-Reo肿瘤靶向性显著优于NKexo组，肿瘤抑制率提升60%（P < 0.001）。结论：成功制备FA-NKexo-Reo递送系统，在中和抗体的存在下，FA-NKexo-Reo可保护并靶向递送Reo到高表达叶酸受体的卵巢癌细胞，从而增强Reo的抗肿瘤作用。

ObjectiveTo investigate the effects of Schisandrae Chinensis Fructus lignans on schizophrenia induced by dizocilpine maleate （MK-801） in mice and to clarify its mechanism. MethodsMale mice of 4-6 weeks old were randomized into blank， model， positive drug， and low-， medium-， and high-dose （40， 80， 160 mg·kg^-1， respectively） Schisandrae Chinensis Fructus lignans groups. The blank group was administrated with distilled water， and the other groups were injected with 0.5 mg·kg^-1 MK-801 to induce schizophrenia symptoms. Meanwhile， risperidone was injected at 0.2 mg·kg^-1 in the positive drug group， and mice in the intervention groups were injected with corresponding drugs for 14 consecutive days. The behavioral changes of mice were observed by autonomous activity test， open field test， forced swimming test， and water maze test. The levels of dopamine （DA） and 5-hydroxytryptamine （5-HT） in the brain and tumor necrosis factor-α （TNF-α） and nuclear factor-κB （NF-κB） in peripheral blood were quantified by enzyme-linked immunosorbent assay （ELISA）. The changes in the prefrontal lobe of mice were observed by hematoxylin-eosin staining， and the changes of the hippocampal tissue were observed by Nissl staining. The protein levels of silencing information regulatory factor 1 （SIRT1） and forkhead box protein O3a （FoxO3a） in the hippocampus of mice were determined by Western blot. ResultsCompared with the model group， low， medium， and high doses of Schisandrae Chinensis Fructus lignans reduced the total number of autonomous activities， total distance in the open field test， immobile time in the forced swimming test， and levels of TNF-α and NF-κB in peripheral blood （P<0.05）， while increasing the number of platform crossings in the water maze test and DA and 5-HT levels in the brain tissue （P<0.05）. Compared with the model group， risperidone and low， medium， and high doses of Schisandrae Chinensis Fructus lignans improve the neural cell morphology in the CA1 region， with full cells in neatly dense arrangement and exhibiting clear membrane boundary. Schisandrae Chinensis Fructus lignans inhibited the expression of SIRT 1 and FoxO3a in the hippocampus （P<0.05）. ConclusionTo sum up， Schisandrae Chinensis Fructus lignans may improve the behavior of schizophrenic mice by activating the SIRT1/FoxO3a signaling pathway to exert neuroprotective effects.

ObjectiveBiochemistry and Molecular Biology, a discipline that elucidates life phenomena at the molecular level, serves as a core foundational course in medical education. It provides the theoretical basis for studying other basic and clinical medical subjects, as well as for understanding pathogenesis, disease diagnosis, and treatment. However, its complex content and highly abstract concepts have posed a dual challenge to traditional teaching models: “inefficient instruction” and “inadequate learning outcomes”. Within limited classroom hours, how to engage students and stimulate their intrinsic motivation, and how to help them recognize, understand, and develop a passion for biochemistry from the perspective of the discipline’s essence, have long been key focuses of curriculum research. MethodsUsing the lipid metabolism chapter as an example, this study employs “Rain Classroom”, a generative artificial intelligence (AI)-assisted platform, to support education in four dimensions: teaching, learning, evaluation, and research. In teaching, it assists instructors through virtual experiments, lesson preparation support, knowledge mapping, and assignment design. For learning, it serves as an intelligent study assistant for students, providing automated assignment review, enabling educational resource sharing, and facilitating personalized learning pathways. In evaluation, the platform automates assignment grading, analyzes student performance data, and offers diagnostic feedback and teaching recommendations. In research, it aids educators in collecting and analyzing teaching data, as well as searching for and summarizing relevant literature. ResultsThe results indicate that an educational model integrating teacher-led instruction, student-centered learning, and generative AI assistance significantly enhances teaching quality, students’ self-directed learning abilities, and knowledge mastery. Furthermore, with the support of generative AI, curriculum-based ideological education—focusing on cutting-edge disciplinary advances and topical medical issues—helps cultivate students’ medical spirit of “honoring life and healing the wounded”, thereby fostering the establishment of appropriate professional values. Finally, while generative AI presents both opportunities and challenges for higher education, this study also analyzes potential risks in its teaching applications, emphasizing the need for both instructors and students to avoid over-reliance and to ensure that technological tools consistently serve the fundamental goals of education. ConclusionThis study demonstrates that integrating generative AI, specifically via the “Rain Classroom” platform, can effectively enhance biochemistry education. By supporting teaching, learning, evaluation, and research, this approach improves both educational effectiveness and student outcomes. It also facilitates the incorporation of cutting-edge knowledge and professional ethics, nurturing a patient-centered mindset. Additionally, the study addresses potential implementation risks to ensure that such technological tools remain aligned with the core purpose of education.

Objective To investigate the value of 3.0 T MRI in-phase/opposed-phase (IP-OP) imaging features in the quantitative assessment of hepatic steatosis after liver transplantation. Methods Clinical data of 115 patients who underwent liver transplantation and completed MRI IP-OP examination and liver biopsy within 3 months were retrospectively collected. According to the gold standard of pathological results, patients were divided into the steatosis group (n=18) and the non-steatosis group (n=97). The relative signal intensity of hepatic parenchyma was measured on MRI IP-OP sequences, and the hepatic fat fraction (HFF) was calculated. Differences in clinical data and imaging features between the two groups were compared, and the efficacy of HFF in the diagnosis of graft hepatic steatosis was evaluated using the receiver operating characteristic (ROC) curve. Results Among the 115 recipients, 18 cases were diagnosed with hepatic steatosis by liver biopsy, including 13 cases of mild steatosis, 3 cases of moderate steatosis and 2 cases of severe steatosis. Compared with the non-steatosis group, the steatosis group had a lower proportion of hepatitis B virus (HBV)-related hepatocellular carcinoma, higher proportions of HBV-related liver failure and alcoholic liver cirrhosis, and higher platelet levels (all P<0.05). There were statistically significant differences in hepatic imaging features between the two groups (all P<0.05). The ROC curve showed that the area under the curve (AUC) of the quantitative value calculated by IP-OP in the diagnosis of graft hepatic steatosis was 0.925 (95% confidence interval 0.870-0.980). Conclusions 3.0 T MRI IP-OP sequence may accurately and non-invasively quantitatively assess the severity of hepatic steatosis after liver transplantation, which is of great value for the early detection of graft hepatic steatosis and the guidance of clinical intervention.

BACKGROUND:Autologous bone,allogeneic bone or artificial bone has been used to promote bone defect repair in the clinic,but the rate of non-healing is still high.The key is to ignore the importance of periosteum in the bone healing process.In the early stage of the project,the project team constructed an electrospinning membrane loaded with vascular endothelial growth factor to highly simulate the intramembranous osteogenesis of natural periosteum at the bone defect site,which promoted bone regeneration to a certain extent.However,the injured area often faces the dilemma of severe inflammatory response mediated by macrophages and lack of seed cells,resulting in the risk of inactivation or diffusion of delivered biological factors.Therefore,it is necessary to further optimize and coordinate the immune regulation and angiogenesis functions of biomimetic periosteum to promote bone repair.OBJECTIVE:To investigate the physicochemical properties of stem cell-engineered bionic periosteum and its role in regulating the inflammatory microenvironment to promote bone repair.METHODS:By combining L-polylactic acid-based microsol electrospinning,type Ⅰ collagen self-assembly and gel stem cell transplantation technology,a bionic periosteum(M@C-B)was constructed,in which the core layer loaded with vascular endothelial growth factor and the shell layer delivered bone marrow mesenchymal stem cells to regulate the immune microenvironment of bone defects.The physicochemical properties of the periosteum were characterized by scanning electron microscopy,transmission electron microscopy,and Fourier transform infrared spectroscopy.A co-culture system was established between the bionic periosteum and macrophages,bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to explore immune regulation and in vitro osteogenic and angiogenic abilities.Finally,the osteogenic properties of the stem cell engineered bionic periosteum were further verified in a rat femoral condyle defect model.RESULTS AND CONCLUSION:(1)Transmission electron microscopy results showed that the micro-sol electrospinning(MS)formed a distinct core-shell structure.Scanning electron microscopy indicated that after the assembly of the collagen-l artificial periosteum(M@C)on the surface of the vascular endothelial growth factor-loaded micro-sol,a distinct"spider web-like"fibrous structure was deposited.Infrared spectroscopy further confirmed the successful self-assembly of collagen-l.Release experiments demonstrated that the M@C group mitigated the burst release phenomenon compared to the MS group,maintaining internal vascular endothelial growth factor activity and sustained release.(2)Live/dead cell staining and CCK-8 assay showed that bone marrow mesenchymal stem cells proliferated well and survived on three types of artificial periosteum:MS,purely aligned poly(L-lactic acid)(PLLA)surface self-assembled collagen-l artificial periosteum(PLLA@C),and vascular endothelial growth factor-loaded micro-sol fiber surface self-assembled collagen-l-bone marrow mesenchymal stem cells artificial periosteum(M@C-B).Among them,the M@C-B group had the highest number of live cells and the fastest proliferation rate.(3)Alkaline phosphatase staining,alizarin red staining,and osteopontin immunofluorescence staining showed that the PLLA@C and M@C-B groups significantly promoted osteogenic differentiation of bone marrow mesenchymal stem cells.Angiogenesis experiments demonstrated that the vascular endothelial growth factor-loaded groups(MS and M@C-B)had longer blood vessel lengths and more reticular vascular-like structures with more cross-linked nodes,with the M@C-B group being the most prominent.(4)Immunofluorescence and flow cytometry showed that artificial periosteum in the M@C-B group significantly inhibited the pro-inflammatory macrophage phenotype and promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype.(5)In vivo studies further confirmed that the M@C-B group showed superior bone mineral density,trabecular thickness,relative bone volume,and trabecular spacing compared to other groups.(6)These results indicate that bone marrow mesenchymal stem cell-engineered artificial periosteum,through the rapid regulation of the bone defect immune microenvironment by the collagen-l-bone marrow mesenchymal stem cells outer phase and the sustained release of vascular endothelial growth factor by the micro-sol electrospinning core-shell structure of the inner phase,synergistically promotes bone healing.

BACKGROUND:Fracture healing is a very complex physiological process,which is influenced by many factors.In recent years,the use of biomechanical factors in fracture healing has been a major focus in the field of orthopedics,and the mechanical stress environment around the fracture end has an important role in regulating fracture healing.Among them,the study of the mechanism of compressive mechanics on the cytokines of fracture ends is a hot spot for bone-related researchers.OBJECTIVE:To summarize the current status and recent advances in the study of the mechanism of action of compressive stress on cytokines in fracture healing in recent years.METHODS:A search with the keywords of"compressive stress,fracture healing,cytokine,bone morphogenetic protein,fibroblast growth factor,platelet-derived growth factor,vascular endothelial growth factor,interleukin,tumor necrosis factor-α"in Chinese and English was conducted in the CNKI,WanFang,PubMed,and Web of Science.Initially 506 articles were retrieved,and 94 eligible articles that met the criteria were screened and finally summarized.RESULTS AND CONCLUSION:Current studies have found that compressive stress has different effects on different cytokines during fracture healing,which can be achieved mainly by influencing cell signaling,gene expression regulation,and modulation of cell behavior.Among them,compressive stress can be linked to cytokines such as bone morphogenetic protein,fibroblast growth factor,platelet-derived growth factor,vascular endothelial growth factor,interleukin,and tumor necrosis factor-α.This process involves cell proliferation,differentiation and migration,inflammatory response,and changes in the environmental and nutritional conditions of the fracture end,which are key factors affecting fracture healing.The whole paper summarizes the complexity of cytokine action mechanism,the mechanism of compressive stress on its regulation needs to be further carried out in-depth research,and the problems and limitations in the research are considered and future prospects.

BACKGROUND:Autologous bone,allogeneic bone or artificial bone has been used to promote bone defect repair in the clinic,but the rate of non-healing is still high.The key is to ignore the importance of periosteum in the bone healing process.In the early stage of the project,the project team constructed an electrospinning membrane loaded with vascular endothelial growth factor to highly simulate the intramembranous osteogenesis of natural periosteum at the bone defect site,which promoted bone regeneration to a certain extent.However,the injured area often faces the dilemma of severe inflammatory response mediated by macrophages and lack of seed cells,resulting in the risk of inactivation or diffusion of delivered biological factors.Therefore,it is necessary to further optimize and coordinate the immune regulation and angiogenesis functions of biomimetic periosteum to promote bone repair.OBJECTIVE:To investigate the physicochemical properties of stem cell-engineered bionic periosteum and its role in regulating the inflammatory microenvironment to promote bone repair.METHODS:By combining L-polylactic acid-based microsol electrospinning,type Ⅰ collagen self-assembly and gel stem cell transplantation technology,a bionic periosteum(M@C-B)was constructed,in which the core layer loaded with vascular endothelial growth factor and the shell layer delivered bone marrow mesenchymal stem cells to regulate the immune microenvironment of bone defects.The physicochemical properties of the periosteum were characterized by scanning electron microscopy,transmission electron microscopy,and Fourier transform infrared spectroscopy.A co-culture system was established between the bionic periosteum and macrophages,bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to explore immune regulation and in vitro osteogenic and angiogenic abilities.Finally,the osteogenic properties of the stem cell engineered bionic periosteum were further verified in a rat femoral condyle defect model.RESULTS AND CONCLUSION:(1)Transmission electron microscopy results showed that the micro-sol electrospinning(MS)formed a distinct core-shell structure.Scanning electron microscopy indicated that after the assembly of the collagen-l artificial periosteum(M@C)on the surface of the vascular endothelial growth factor-loaded micro-sol,a distinct"spider web-like"fibrous structure was deposited.Infrared spectroscopy further confirmed the successful self-assembly of collagen-l.Release experiments demonstrated that the M@C group mitigated the burst release phenomenon compared to the MS group,maintaining internal vascular endothelial growth factor activity and sustained release.(2)Live/dead cell staining and CCK-8 assay showed that bone marrow mesenchymal stem cells proliferated well and survived on three types of artificial periosteum:MS,purely aligned poly(L-lactic acid)(PLLA)surface self-assembled collagen-l artificial periosteum(PLLA@C),and vascular endothelial growth factor-loaded micro-sol fiber surface self-assembled collagen-l-bone marrow mesenchymal stem cells artificial periosteum(M@C-B).Among them,the M@C-B group had the highest number of live cells and the fastest proliferation rate.(3)Alkaline phosphatase staining,alizarin red staining,and osteopontin immunofluorescence staining showed that the PLLA@C and M@C-B groups significantly promoted osteogenic differentiation of bone marrow mesenchymal stem cells.Angiogenesis experiments demonstrated that the vascular endothelial growth factor-loaded groups(MS and M@C-B)had longer blood vessel lengths and more reticular vascular-like structures with more cross-linked nodes,with the M@C-B group being the most prominent.(4)Immunofluorescence and flow cytometry showed that artificial periosteum in the M@C-B group significantly inhibited the pro-inflammatory macrophage phenotype and promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype.(5)In vivo studies further confirmed that the M@C-B group showed superior bone mineral density,trabecular thickness,relative bone volume,and trabecular spacing compared to other groups.(6)These results indicate that bone marrow mesenchymal stem cell-engineered artificial periosteum,through the rapid regulation of the bone defect immune microenvironment by the collagen-l-bone marrow mesenchymal stem cells outer phase and the sustained release of vascular endothelial growth factor by the micro-sol electrospinning core-shell structure of the inner phase,synergistically promotes bone healing.

BACKGROUND:Fracture healing is a very complex physiological process,which is influenced by many factors.In recent years,the use of biomechanical factors in fracture healing has been a major focus in the field of orthopedics,and the mechanical stress environment around the fracture end has an important role in regulating fracture healing.Among them,the study of the mechanism of compressive mechanics on the cytokines of fracture ends is a hot spot for bone-related researchers.OBJECTIVE:To summarize the current status and recent advances in the study of the mechanism of action of compressive stress on cytokines in fracture healing in recent years.METHODS:A search with the keywords of"compressive stress,fracture healing,cytokine,bone morphogenetic protein,fibroblast growth factor,platelet-derived growth factor,vascular endothelial growth factor,interleukin,tumor necrosis factor-α"in Chinese and English was conducted in the CNKI,WanFang,PubMed,and Web of Science.Initially 506 articles were retrieved,and 94 eligible articles that met the criteria were screened and finally summarized.RESULTS AND CONCLUSION:Current studies have found that compressive stress has different effects on different cytokines during fracture healing,which can be achieved mainly by influencing cell signaling,gene expression regulation,and modulation of cell behavior.Among them,compressive stress can be linked to cytokines such as bone morphogenetic protein,fibroblast growth factor,platelet-derived growth factor,vascular endothelial growth factor,interleukin,and tumor necrosis factor-α.This process involves cell proliferation,differentiation and migration,inflammatory response,and changes in the environmental and nutritional conditions of the fracture end,which are key factors affecting fracture healing.The whole paper summarizes the complexity of cytokine action mechanism,the mechanism of compressive stress on its regulation needs to be further carried out in-depth research,and the problems and limitations in the research are considered and future prospects.

Objective To explore the relationship between intestinal flora imbalance and pulmonary function in patients with chronic obstructive pulmonary disease (COPD), and to analyze the related influencing factors. Methods A total of 310 patients with COPD who were admitted to Air Force Military Medical University Tangdu Hospital from June 2022 to December 2024 were retrospectively analyzed. Based on intestinal flora status, the enrolled patients were classified into imbalance group (n=83) and non-imbalance group (n=227). Logistic regression analysis was conducted to analyze the independent related factors of intestinal flora imbalance in COPD patients. Based on the above factors, a prediction model was constructed, and ROC curve analysis model was applied to analyze the predictive value of the model on intestinal flora imbalance. Results Logistic regression analysis revealed that age, IL-6, albumin, pulmonary function, long-term bed rest and long-term use of antibiotics were related to intestinal flora imbalance in COPD patients (all P<0.05). ROC results of the Logistic prediction model showed that the area under the curve, sensitivity, specificity and 95%CI were 0.961, 0.880, 0.996 and 0.932-0.989 respectively. Conclusion The intestinal flora imbalance in patients with COPD is closely related to lung function, age, inflammatory status, nutritional indicators, activity ability and antibiotic use.

OBJECTIVE To investigate the improved anesthesia method of arytenoid cartilage reduction under general anesthesia in the treatment of arytenoid dislocation.METHODS The clinical data of 12 patients who underwent modified arytenoid cartilage reduction under general anesthesia in Beijing Tongren Hospital from July 2020 to March 2024 were retrospectively analyzed.To evaluate and analyze the modified anesthesia method of maintaining low degree of neuromuscular block during operation,the recovery of arytenoid cartilage movement and sound after operation.RESULTS All the 12 patients successfully completed arytenoid cartilage reduction.The articulation,arytenoid movement and glottis closure were improved significantly.Compared with the total voice handicap index(VHI),physical scores,functional scores and emotional scores before reduction,the scores at 1 month after surgery were significantly lower[83.5(75-91)vs.13(7-19),30.5(26.5-33)vs.5.5(3-7),25.5(22.5-29)vs.4(2-6),26(23.5-30)vs.4(1.5-6),P<0.001].No complications such as laryngeal spasm and laryngeal edema occurred during perioperative period.CONCLUSION Arytenoid cartilage reduction under modified general anesthesia has high safety,good patient cooperation and high reduction success rate.It provides a new option for the treatment of arytenoid dislocation.