Sarcopenia is a systemic skeletal muscle disease characterized by the gradual decline of muscle mass，strength，and function，and its occurrence and development are related to multiple factors，involving several signaling pathways. Among them，the phosphatidylinositol 3-kinase/protein kinase B（PI3K/Akt） signaling pathway，as a key pathway regulating cellular growth，survival，and metabolism，plays an important role in the formation and development of sarcopenia. Its abnormal activation or deactivation may lead to an imbalance in muscle protein metabolism，resulting in muscle atrophy and reduction. Modern medicine is still in the exploratory stage of treatment for sarcopenia. Traditional Chinese medicine （TCM），with its multi-pathway and multi-target characteristics，has shown increasing advantages in the prevention and treatment of sarcopenia. In recent years，various monomers， extracts，and compound formulas of TCM have been proven to effectively prevent and treat sarcopenia by promoting muscle cell protein synthesis，reducing protein degradation，inhibiting cell apoptosis and inflammatory response，and improving mitochondrial function. This paper reviewed the improvement effects of TCM on sarcopenia based on the PI3K/Akt pathway and explored its specific action mechanisms， aiming to provide new insights for the treatment of sarcopenia with TCM.

BACKGROUND:In vitro construction of tissue-engineered intestinal models plays an important role in intestinal regeneration and intestinal disease research.The interaction of intestinal nervous system and intestinal epithelial barrier to maintain body homeostasis is a hot topic in the bionic construction of tissue-engineered intestinal tract.OBJECTIVE:To construct a bionic model that can mimic the enteric nervous system in vivo.METHODS:Using fibroin protein with villus structure as scaffold,human induced neural stem cells solidified with collagen were added to intestinal epithelial cells(Caco-2 and HT29-MTX-E12)for 3-day culture to construct a co-culture system of intestinal epithelial cells and nerve cells(co-culture group).Human induced neural stem cells or intestinal epithelial cells cultured alone that were inoculated with fibroin scaffolds were set as controls.Cell morphology was observed by scanning electron microscopy and hematoxylin-eosin staining.Cell activity was detected by Live/Dead cell staining.Human induced neural stem cell differentiation was detected by β-microtubulin immunofluorescence staining.Intestinal epithelial histological properties and barrier function were detected by microvillin,sucrase-isomaltase,tight junction protein 1,E-calmodulin,and mucin-2 immunofluorescence staining.The function of mucus secretion from intestinal epithelial cells was detected by Alcian blue staining.Alkaline phosphatase staining was performed to detect differentiation of intestinal epithelial cells,at the same time,sucrase-isomaltase,tight junction protein 1,and alkaline phosphatase mRNAs were detected by RT-qRCR.RESULTS AND CONCLUSION:The neuralized intestinal mucosal co-culture model with villi structure was successfully constructed,and neural stem cells and intestinal epithelial cells on the fibroin scaffold showed good cellular activities.After neuralization,the activity of alkaline phosphatase and sucrase-isomaltase in intestinal epithelial cells was enhanced,while the expression level of tight junction protein 1 was up-regulated.To conclude,the neuralized bionic intestinal epithelial model is beneficial to the maturation of intestinal mucosal epithelial cells and the formation of barrier function.

BACKGROUND:Plate fixation is the mainstream method for the surgical treatment of distal femoral fractures.The intramedullary nailing has the advantages of minimally invasive,such as less soft tissue injury and bone blood supply destruction.At the same time,it is a central fixation and has better biomechanical effect.Therefore,retrograde intramedullary nailing has become another option for the internal fixation of distal femoral fractures.OBJECTIVE:The biomechanical characteristics of new retrograde intramedullary nail on lateral femur condyle,common femoral retrograde intramedullary nail,and lateral femur condyle anatomical locking plate for the treatment of A2-type distal femoral fractures were compared using finite element analysis,and the advantages of new retrograde intramedullary nail on lateral femur condyle was studied.METHODS:A new retrograde intramedullary nail on lateral femur condyle was designed,which was inserted into the bone cortex in front of the insertion point of the lateral collateral ligament of the lateral femoral condyle.A CT scan was performed on the lower limb bone of a male volunteer,and a three-dimensional model of the femur was established.The model was then segmented to create a three-dimensional model of a femoral distal A2-type fracture,The three-dimensional models of small(small group),standard type retrograde intramedullary nail on the lateral femoral condyle(standard group),common retrograde intramedullary needle(common group),and lateral femur condyle anatomical locking plate(plate group)were established respectively.The axial stresses of 600,1 800 N and the torsional load of 4 000,8 000 N·mm were applied to the models,and the displacement and stress of femur and the displacement,stress and shear force of internal fixators were observed in each group.RESULTS AND CONCLUSION:(1)When subjected to axial load of 600 and 1 800 N,the femoral peak displacement,the femoral peak stress,and the peak stress of interal fixation in the standard group were the lowest among the four groups.(2)When subjected to torsional load of 4 000 and 8 000 N·mm,the femoral peak displacement and peak displacement of the internal fixation in the standard group were the lowest among the four groups.(3)Compared with femoral lateral condylar locking plate and common retrograde intramedullary needle,the new retrograde intramedullary needle on lateral femur condyle has mechanical advantages of reducing stress concentration and decreasing the risk of internal fixation failure.

BACKGROUND:With changing lifestyles and aging,sagittal spinal imbalance has become a common orthopedic issue significantly affecting knee and pelvic function.Understanding the impact of sagittal spinal imbalance and its compensatory mechanisms is crucial for improving the clinical management of chronic pain.OBJECTIVE:To evaluate the alignment of the spine-pelvis-lower extremities using whole-body EOS imaging,analyze the correlation between spinal sagittal imbalance and knee joint parameters,and explore their compensatory mechanisms.METHODS:A total of 71 patients with chronic low back pain or patellofemoral pain who visited Department of Orthopedics,First Affiliated Hospital of Soochow University between January 1,2021 and December 31,2023 were included.Radiographic measurements were performed using whole-body EOS to determine pelvic tilt,pelvic incidence,lumbar lordosis,sagittal vertical axis,global tilt,hip-knee-angle,knee flexion angle,lateral distal femoral angle,and medial proximal tibial angle.Patients were classified into normal group(pelvic incidence-lumbar lordosis＜10°),compensated group(10°＜pelvic incidence-lumbar lordosis＜20°),and decompensated group(pelvic incidence-lumbar lordosis＞20°)based on the SRS-Schwab spinal deformity classification according to pelvic incidence-lumbar lordosis difference.The differences in radiographic parameters among the groups were analyzed.The differences in American Knee Society Knee Score and Oswestry Disability Index scores were compared among each group.Patients were divided into chronic low back pain group and non-chronic low back pain group,patellofemoral pain group and non-patellofemoral pain group based on clinical symptoms,and the relationship between radiographic parameter differences and clinical symptoms was analyzed.RESULTS AND CONCLUSION:(1)When pelvic incidence-lumbar lordosis was less than 20°,lateral distal femoral angle and medial proximal tibial angle tended to stabilize.When pelvic incidence-lumbar lordosis was greater than 20°,it showed a linear correlation with lateral distal femoral angle and medial proximal tibial angle,with lateral distal femoral angle increasing and medial proximal tibial angle decreasing with increasing pelvic incidence-lumbar lordosis values.(2)Compared with the normal group,the compensated group had significantly increased pelvic tilt(P＜0.01),while knee joint parameters hip-knee-angle and knee flexion angle showed no significant differences;the decompensated group showed significant increases in pelvic tilt(P＜0.01),and decreases in hip-knee-angle,and knee flexion angle(P＜0.01).Compared with the compensated group,the decompensated group showed a significant decrease in hip-knee-angle(P＜0.05),but had no significant differences in pelvic tilt and knee flexion angle.(3)Compared with the non-patellofemoral pain group,patients with patellofemoral pain had significant decreases in spinal lumbar lordosis,lateral distal femoral angle,and medial proximal tibial angle(P＜0.05)and a significant increase in pelvic incidence-lumbar lordosis(P＜0.05).(4)Patients with low back pain had significant differences in radiographic parameters compared with the non-chronic low back pain group(P＜0.05).(5)Compared with the normal group,both the compensated and decompensated groups showed a significant decrease in American Knee Society Knee Score scores and a significant increase in Oswestry Disability Index scores(P＜0.05).Compared with the compensated group,the decompensated group showed a significant decrease in American Knee Society Knee Score scores and a significant increase in Oswestry Disability Index scores(P＜0.05).(6)Pelvic incidence-lumbar lordosis values increased with age and were higher in females compared with males.(7)This study systematically reveals the spine and lower limbs play an important role in disease progression and clinical symptoms.Associated symptoms low back pain and patellofemoral pain are related to the stability of the spine-pelvis-lower extremity alignment.Furthermore,spinal sagittal imbalance is more severe in elderly and female patients.

BACKGROUND:Studies have shown that platelet-derived growth factor BB can stimulate the proliferation and osteogenic differentiation of mesenchymal stem cells and accelerate the calcification process of osteoblast-like cells.However,its clinical application has problems such as short half-life and easy decomposition.Loading the growth factor onto a suitable biomaterial scaffold can enable its slow and continuous release and maintain an effective concentration,which has become a hot topic in current research.OBJECTIVE:To observe the effect of chitosan/reduced graphene oxide scaffolds loaded with platelet-derived growth factor BB on the repair of alveolar bone defect in rats.METHODS:(1)Chitosan/reduced graphene oxide scaffolds(referred to as CS/rGO scaffolds)and chitosan/reduced graphene oxide scaffolds loaded with different mass concentrations(5,10,15,and 20 mg/L)of platelet-derived growth factor BB(referred to as CS/rGO/PDGF-BB-5,CS/rGO/PDGF-BB-10,CS/rGO/PDGF-BB-15,and CS/rGO/PDGF-BB-20 scaffolds)were prepared respectively.The five groups of scaffolds were co-cultured with rat periodontal ligament stem cells.The cell proliferation and migration were detected by CCK-8 assay and Transwell chamber assay,respectively,to screen the appropriate growth factor loading mass concentration for subsequent experiments.CS/rGO scaffolds(or extracts)and CS/rGO/PDGF-BB-15 scaffolds(or extracts)were co-cultured with rat periodontal ligament stem cells,and the osteogenic differentiation and angiogenic ability of the cells were detected.(2)The alveolar bone defect model was prepared in front of the bilateral maxillary first molars of 16 SD rats,and the rats were randomly divided into 4 intervention groups:the blank control group did not receive any intervention,the simple scaffold group was implanted with CS/rGO/PDGF-BB-15 scaffold,the control group was implanted with CS/rGO scaffold and rat periodontal ligament stem cell complex,and the experimental group was implanted with CS/rGO/PDGF-BB-15 scaffold and rat periodontal ligament stem cell complex,with 4 rats in each group.Twelve weeks after surgery,the bone repair of the alveolar bone defect was observed by Micro CT scanning and hematoxylin-eosin staining.RESULTS AND CONCLUSION:(1)CS/rGO/PDGF-BB-5,CS/rGO/PDGF-BB-10,CS/rGO/PDGF-BB-15,and CS/rGO/PDGF-BB-20 scaffolds could promote the proliferation and migration of rat periodontal ligament stem cells.Among them,the CS/rGO/PDGF-BB-15 scaffold had the most significant effect on promoting cell proliferation and migration,and this scaffold was used for subsequent experiments.Compared with the CS/rGO scaffold,the CS/rGO/PDGF-BB-15 scaffold could promote the osteogenic and angiogenic differentiation of rat periodontal ligament stem cells.(2)Micro CT scanning and hematoxylin-eosin staining results showed that the experimental group had the best alveolar bone defect repair effect,and a large amount of new bone tissue and blood vessel formation could be seen.(3)The chitosan/reduced graphene oxide scaffold loaded with platelet-derived growth factor BB can effectively promote the repair of rat alveolar bone defects by promoting the proliferation,migration,angiogenic and osteogenic differentiation of rat periodontal ligament stem cells.

BACKGROUND:Rheumatoid arthritis is influenced by complex genetic and environmental factors.Although observational studies have found some correlation between plasma proteins and rheumatoid arthritis,the susceptibility to confounding and reverse causation makes it difficult to clarify whether these proteins are pathogenic factors of rheumatoid arthritis.OBJECTIVE:To explore the potential of plasma proteins as biomarkers and therapeutic targets in rheumatoid arthritis through Mendelian randomization analysis of plasma proteins in the onset and progression of rheumatoid arthritis.METHODS:A large-scale two-sample Mendelian randomization analysis was conducted to comprehensively assess the causal relationships between 1 553 circulating proteins and rheumatoid arthritis based on the Decode database(developed by Decode Genetics in Iceland,which contains genomic data from the Icelandic population),the MR-Base platform(developed by a team of researchers at the University of Oxford in the United Kingdom,specifically designed to provide genetic and phenotypic data for Mendelian randomization analyses),and the GWAS Catalog platform(developed by the European Institute of Bioinformatics,which provides data for genome wide association studies worldwide).The causal effects were estimated using the Wald ratio and inverse variance weighting methods,with Bonferroni correction applied to control for false positives caused by multiple testing.To ensure the robustness of the results,sensitivity analyses were performed to validate the positive causal relationship between circulating proteins and rheumatoid arthritis,and Bayesian colocalization and phenome scanning were used to exclude confounding effects and horizontal pleiotropy.Additionally,external validation was carried out using new plasma protein datasets to reduce the likelihood of false discoveries.Finally,small-molecule compounds associated with candidate proteins were identified using the Drug Signatures Database(DsigDB),and molecular docking was performed to predict the binding patterns and energies between proteins and compounds,identifying the most stable and likely binding molecules and mechanisms.RESULTS AND CONCLUSION:(1)Sensitivity analyses,including Bayesian colocalization and phenome scanning,identified four plasma proteins with reliable causal relationships with rheumatoid arthritis:FCRL3,IL6R,ICOSLG,and TNFAIP3.Their genetic effects were estimated as follows:FCRL3[odds ratio(OR)=1.12,95％confidence interval(CI):1.07-1.17],IL6R(OR=0.94,95％CI:0.91-0.96),ICOSLG(OR=2.42,95％CI:1.67-3.52),and TNFAIP3(OR=2.19,95％CI:1.88-2.56).Furthermore,molecular docking analysis revealed that the small-molecule compound benzo[a]pyrene exhibited favorable binding with these candidate proteins,suggesting its potential as a therapeutic agent for rheumatoid arthritis.(2)This study provides a comprehensive analysis of the genetic causal relationships of FCRL3,IL6R,ICOSLG,and TNFAIP3 in rheumatoid arthritis.These proteins not only serve as potential molecular biomarkers for rheumatoid arthritis risk screening and disease prevention,but also offer key candidate targets for further understanding the pathogenic mechanisms of rheumatoid arthritis and developing targeted therapies.Although the study is based on European populations,its findings offer important insights for biomedical research in China.By incorporating Mendelian randomization methods to analyze genetic causality,future research on rheumatoid arthritis in the Chinese population could provide more accurate causal inferences,offering theoretical support for localized risk assessment and treatment strategies.

BACKGROUND:In vitro construction of tissue-engineered intestinal models plays an important role in intestinal regeneration and intestinal disease research.The interaction of intestinal nervous system and intestinal epithelial barrier to maintain body homeostasis is a hot topic in the bionic construction of tissue-engineered intestinal tract.OBJECTIVE:To construct a bionic model that can mimic the enteric nervous system in vivo.METHODS:Using fibroin protein with villus structure as scaffold,human induced neural stem cells solidified with collagen were added to intestinal epithelial cells(Caco-2 and HT29-MTX-E12)for 3-day culture to construct a co-culture system of intestinal epithelial cells and nerve cells(co-culture group).Human induced neural stem cells or intestinal epithelial cells cultured alone that were inoculated with fibroin scaffolds were set as controls.Cell morphology was observed by scanning electron microscopy and hematoxylin-eosin staining.Cell activity was detected by Live/Dead cell staining.Human induced neural stem cell differentiation was detected by β-microtubulin immunofluorescence staining.Intestinal epithelial histological properties and barrier function were detected by microvillin,sucrase-isomaltase,tight junction protein 1,E-calmodulin,and mucin-2 immunofluorescence staining.The function of mucus secretion from intestinal epithelial cells was detected by Alcian blue staining.Alkaline phosphatase staining was performed to detect differentiation of intestinal epithelial cells,at the same time,sucrase-isomaltase,tight junction protein 1,and alkaline phosphatase mRNAs were detected by RT-qRCR.RESULTS AND CONCLUSION:The neuralized intestinal mucosal co-culture model with villi structure was successfully constructed,and neural stem cells and intestinal epithelial cells on the fibroin scaffold showed good cellular activities.After neuralization,the activity of alkaline phosphatase and sucrase-isomaltase in intestinal epithelial cells was enhanced,while the expression level of tight junction protein 1 was up-regulated.To conclude,the neuralized bionic intestinal epithelial model is beneficial to the maturation of intestinal mucosal epithelial cells and the formation of barrier function.

Objective To investigate the heterogeneity and key molecular features of epithelial cells in triple-negative breast cancer (TNBC), identify prognostic biomarkers, and develop a robust survival prediction model. Methods Using TNBC single-cell transcriptomic data, epithelial cells were extracted, normalized, and subclustered to characterize their molecular signatures and functional differences. High-dimensional weighted gene co-expression network analysis (hdWGCNA) was applied to establish co-expression modules in epithelial cells. Multiple machine learning algorithms were integrated to select key prognostic genes and develop a risk-score model, whose performance was evaluated using receiver operating characteristic (ROC) curves and Kaplan-Meier (K-M) survival analysis. In addition, the immune microenvironment features and potential drug-response differences between the high- and low-risk groups were systematically assessed. Finally, PCR was performed to validate the expression differences of the key genes between tumor and normal tissues. Results We characterized the composition and molecular features of TNBC epithelial subpopulations and identified a TNBC-associated epithelial subset. By integrating hdWGCNA with machine learning approaches, 10 key genes were selected to construct a prognostic model, which effectively stratified patients into distinct survival-risk groups and demonstrated favorable predictive performance in ROC and K-M analyses. Immune profiling revealed the differences in the infiltration levels of seven immune cell types and immune function-related features between the high- and low-risk groups. Drug-sensitivity analysis suggested potential differential responses to eight agents across the risk groups. PCR validation further confirmed the differential expression of the ten signature genes between tumor and normal tissues. Conclusion This study reveals epithelial heterogeneity in TNBC at single-cell resolution and establishes a 10-gene prognostic model, which may facilitate the stratification of TNBC risk and the evaluation of immune characteristics and potential therapeutic strategies.

Background Neck-related work-related musculoskeletal disorders (WMSDs) are a major type of musculoskeletal disorders with a relatively high proportion. Shanghai has a large number of occupational populations; however, the occurrence of WMSDs at neck among the occupational populations across industries in this city has not been reported, and needs to be addressed. Objective To understand the occurrence of neck-related WMSDs and their influencing factors among occupational populations in 8 industries in Shanghai, and to provide a scientific basis for the prevention and control of WMSDs in this population. Methods From February 2024 to February 2025, a cross-sectional survey employed stratified cluster sampling to select 7829 employed workers from 48 enterprises across 8 industries in Shanghai. The study investigated the occurrence of neck-related WMSDs among the participants over the preceding 12 months. Logistic regression analysis was employed to examine the relationships between WMSDs and various occupational factors. Results A total of 7770 questionnaires were collected, yielding an effective response rate of 99.2%. Overall, the positive rate of neck-related WMSDs among the participants was 11.89% (924/7770). Among different industries, the environmental sanitation industry (19.48%), pharmaceutical manufacturing industry (14.57%), and cigarette manufacturing industry (13.66%) had higher prevalence of neck-related WMSDs. Univariate analysis showed that the risk of neck-related WMSDs was higher in the following groups: those with a job tenure ≥5 years in the current position (OR=1.50–1.70), females (OR=1.77), those with higher education levels (master’s degree or above, OR=2.27), and those with worse self-rated health (very poor health, OR=4.38) (P＜0.05). Multivariate logistic regression analysis identified the following independent risk factors for neck WMSDs: environmental sanitation industry (OR=7.30, 95%CI: 4.72, 11.87), higher educational attainment (master’s degree or above: OR=2.16, 95%CI: 1.36, 3.35), worse self-rated health status (very poor: OR=1.95, 95%CI: 1.31, 2.85), work performed in a single workshop (OR=1.36, 95%CI: 1.13, 1.64), understaffing (OR=1.46, 95%CI: 1.25, 1.70), slight neck forward flexion (OR=1.64, 95%CI: 1.32, 2.06), severe neck forward flexion (OR=2.55, 95%CI: 1.97, 3.30), and maintaining a fixed neck posture for a prolonged period (OR=2.28, 95%CI: 1.93, 2.70). Conversely, work rotation (OR=0.75, 95%CI: 0.65, 0.87), adequate rest (OR=0.70, 95%CI: 0.60, 0.82), and severe back flexion (OR=0.63, 95%CI: 0.46, 0.85) were protective factors against neck-related WMSDs. For the nomogram, the area under the curve (AUC)=0.75 (95%CI: 0.74, 0.77), Hosmer-Lemeshow test P=0.764, and Brier score=0.094, indicating that the model had good discrimination and calibration. Conclusion Among the occupational populations in Shanghai, the environmental sanitation industry, pharmaceutical manufacturing industry, and cigarette manufacturing industry are identified as high-risk industries for neck-related WMSDs. Industry affiliation, educational level, work organization patterns, and awkward neck working postures are confirmed as the core influencing factors for the development of neck-related WMSDs. Targeted and comprehensive intervention measures should be formulated focusing on the aforementioned high-risk industries and key influencing factors. Multi-dimensional collaborative efforts, including ergonomic optimization, improvement of labor management systems, and strengthened health education and promotion, should be implemented to effectively control the risk of neck-related WMSDs in the occupational population, and to provide robust statistical evidence for the advancement of regional occupational health prevention and control strategies.

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.