Background The job content of aircraft maintenance workers is complex, with high intensity and high requirements, and they are prone to work-related musculoskeletal disorders (WMSDs), but related research is relatively rare. Objective To investigate the positive rate of WMSDs among aircraft maintenance workers, evaluate ergonomic load, and analyze the risk factors of WMSDs. Methods We used a self-compiled questionnaire for WMSDs and the Quick Exposure Checklist (QEC) to investigate the basic situation, positive rate of WMSDs, and the ergonomic load of 2271 male maintenance workers in 6 departments of an aircraft maintenance company, including airline maintenance, overall overhaul, accessory/landing gear overhaul, engine overhaul, product customization, and power assist. We used a logistic regression model to analyze the risk factors of WMSDs in the neck, shoulder, hand/wrist, and lower back. Results The positive rate of WMSDs in the past 12 months was 70.4% (1598/2271) and the positive rate of WMSDs in different body parts ranged from 6.6% to 49.5%, with the top three parts of lower back, neck, and knee, respectively. There were statistically significant differences in the positive rate among different departments (P<0.05). The average QEC scores for neck, hand/wrist, and back (static) were moderate, while those for shoulder and back (dynamic) were high, and the body part specific positive rate of WMSDs increased with the increase of ergonomic load level. Working years (5-<10 years, ≥20 years), working with back flexed or twisted or side bent (moderately, excessively), high maximum force level exerted by one hand, and feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of lower back pain (OR=1.486, 1.505; 2.151, 3.769; 1.637; 2.110, 2.407; 1.637, 1.794; P<0.05). Working years (15-<20 years, ≥20 years), working with head/neck bent or twisted (occasionally, continuously), feeling difficult (sometimes) and stressful (very) while working were associated with higher risks of neck pain (OR=1.731, 1.586; 3.732, 8.341; 1.633; 1.696; P<0.05). Working years (15-<20 years, ≥20 years), working with hands in a high position (at shoulder or above), very frequent shoulder/arm movements, feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of shoulder pain (OR=1.587, 1.709; 1.299; 1.521; 1.643, 2.239; 1.659, 1.977; P<0.05). Working with wrist at deviated or bent angle, high repetition of similar movements, feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of hand/wrist pain (OR=1.692; 1.670; 1.827, 2.884; 2.190, 2.625; P <0.05) . Physical exercise after work (≥3 times·week⁻¹) was associated with a lower risk of neck pain (OR=0.582, P<0.05). Shift workers were at a lower risk of shoulder pain and hand/wrist pain (OR=0.737 and 0.554, P<0.05). Conclusion The high positive rate of WMSDs symptoms among aircraft maintenance workers is related to individual, occupational ergonomic, and psychological factors, and active prevention and intervention should be taken.

ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

BACKGROUND:Currently,different methods of model establishment have been derived from different injury modes of spinal cord injury.Traditional physical injury modeling methods have their own advantages and disadvantages,and there is a lack of more effective and stable animal models of spinal cord injury. OBJECTIVE:To establish a reproducible,controllable,trauma-free,low-mortality,more stable,widely applicable,and short-term postoperative care rat model of spinal cord injury. METHODS:Forty Sprague-Dawley rats with similar body mass and ages were randomly divided into a control group and an improved group,with 20 rats in each group.Animal models of spinal cord injury in the control group were constructed using a clip model method,while the improved group used a modified ligation method based on the compression method to make the spinal cord injury models using suture ligation based on fenestration.Postoperative comparisons were made between the two groups,assessing urination behavior,hematuria,pyuria(infection rate),mortality,scoliosis rate and Basso-Beattie-Bresnahan locomotor rating scale scores at 1,3,5,and 7 days after modeling. RESULTS AND CONCLUSION:Compared with the conventional modeling method,the modified ligation method based on the compression method resulted in faster recovery of urination behavior,lower hematuria rate,lower infection rate,lower mortality rate,lower scoliosis rate,and more concentrated and stable Basso-Beattie-Bresnahan scores(all below 2 points within 1 week).This proves that the modified ligation method based on compression is more suitable for the establishment of spinal cord injury models in rats.

Bufalin(BF)has a significant anti-tumor effect, but its clinical application is severely restricted by its high toxicity and poor water solubility. In this study, Scrophularia ningpoensis polysaccharide(SNP)and ursodeoxycholic acid(UDCA) were synthesized into an SNP-UDCA conjugate. BF was encapsulated to prepare BF/SNP-UDCA nanoparticles(NPs). The amphiphilic compound SNP-UDCA was synthesized via the one-step method, and its structure was characterized by Fourier-transform infrared spectroscopy(FT-IR)and proton nuclear magnetic resonance(~1H-NMR). The preparation process of BF/SNP-UDCA NPs was optimized through single-factor investigations. The encapsulation efficiency and drug-loading capacity of BF/SNP-UDCA NPs were determined by high-performance liquid chromatography(HPLC). The molecular form of BF/SNP-UDCA NPs was characterized by using a transmission electron microscope, X-ray diffraction(XRD), and differential scanning calorimeter(DSC). Additionally, the stability of BF/SNP-UDCA NPs was evaluated. The release behavior of BF/SNP-UDCA NPs at different pH values was determined by dialysis. The in vitro anti-tumor effect of BF/SNP-UDCA NPs was evaluated by MTT cytotoxicity assay, flow cytometry for apoptosis, and cellular uptake. The in vitro liver targeting was evaluated by measuring cellular uptake by laser confocal microscopy. The results demonstrated that the SNP-UDCA conjugate was successfully synthesized through an esterification reaction between SNP and UDCA. The preparation process of BF/SNP-UDCA NPs was as follows: the feed ratio of SNP-UDCA to BF was 2∶1, the ultrasonic time was 30 minutes, and the stirring time was two hours. The prepared BF/SNP-UDCA NPs were spherical in shape, with a particle size of(252.74±6.05)nm, an encapsulation efficiency of 65.00%±2.51%, and a drug-loading capacity of 6.80%±0.44%. The XRD and DSC results indicated that BF was encapsulated within the NPs and existed in a molecular or amorphous state. The short-term stability of BF/SNP-UDCA NPs and stability in DMEM medium are good, and their in vitro release behavior followed the first-order equation and was pH-dependent according to the in vitro experiment. Compared with BF, BF/SNP-UDCA NPs at the same concentration showed significantly stronger cytotoxicity and apoptotic effects on HepG2 cells(P<0.05, P<0.01). The uptake of coumarin 6(C6)/SNP-UDCA NPs in HepG2 cells was time-dependent and higher than that in HeLa cells at the same concentration of C6/SNP-UDCA NPs. Moreover, after treatment with SNP, the uptake of C6/SNP-UDCA NPs in HepG2 cells decreased. In conclusion, the preparation process of BF/SNP-UDCA NPs was simple and feasible. BF/SNP-UDCA NPs could enhance the targeting ability and inhibitory effect of BF on liver cancer cells. This study will provide a foundation for liver-targeting nanoformulations of BF.
Bufanolides/pharmacology* ; Nanoparticles/chemistry* ; Humans ; Drug Carriers/chemistry* ; Ursodeoxycholic Acid/chemistry* ; Antineoplastic Agents/pharmacology* ; Polysaccharides/chemistry* ; Scrophularia/chemistry* ; Liver Neoplasms/physiopathology* ; Hep G2 Cells

T-cell acute lymphoblastic leukemia (T-ALL) is a highly aggressive hematologic malignancy with a poor prognosis, despite advancements in treatment. Many patients struggle with relapse or refractory disease. Investigating the role of the super-enhancer (SE) regulated gene ubiquitin-specific protease 20 (USP20) in T-ALL could enhance targeted therapies and improve clinical outcomes. Analysis of histone H3 lysine 27 acetylation (H3K27ac) chromatin immunoprecipitation sequencing (ChIP-seq) data from six T-ALL cell lines and seven pediatric samples identified USP20 as an SE-regulated driver gene. Utilizing the Cancer Cell Line Encyclopedia (CCLE) and BloodSpot databases, it was found that USP20 is specifically highly expressed in T-ALL. Knocking down USP20 with short hairpin RNA (shRNA) increased apoptosis and inhibited proliferation in T-ALL cells. In vivo studies showed that USP20 knockdown reduced tumor growth and improved survival. The USP20 inhibitor GSK2643943A demonstrated similar anti-tumor effects. Mass spectrometry, RNA-Seq, and immunoprecipitation revealed that USP20 interacted with hypoxia-inducible factor 1 subunit alpha (HIF1A) and stabilized it by deubiquitination. Cleavage under targets and tagmentation (CUT&Tag) results indicated that USP20 co-localized with HIF1A, jointly modulating target genes in T-ALL. This study identifies USP20 as a therapeutic target in T-ALL and suggests GSK2643943A as a potential treatment strategy.

Glioblastoma (GBM) is a highly aggressive primary brain tumor characterized by poor prognosis. Conventional chemo-radiotherapy demonstrates limited therapeutic efficacy and is often accompanied by significant side effects, largely due to factors such as drug resistance, radiation resistance, the presence of the blood-brain barrier (BBB), and the activation of DNA damage repair mechanisms. There is a pressing need to enhance treatment efficacy, with BRD4 identified as a promising target for increasing GBM sensitivity to therapy. Lacking small molecule inhibitors, BRD4 can be degraded using PROteolysis Targeting Chimera (PROTAC), thereby inhibiting DNA damage repair. To deliver PROTAC, SIAIS171142 (SIS) effectively, we designed a responsive nanocapsule, MPL_(SS)P@SIS, featuring GBM-targeting and GSH-responsive drug release. Modified with 1-methyl-l-tryptophan (MLT), nanocapsules facilitate targeted delivery of SIS, downregulating BRD4 and sensitizing GBM cells to radiotherapy and chemotherapy. After intravenous administration, MPL_(SS)P@SIS selectively accumulates in tumor tissue, enhancing the effects of radiotherapy and temozolomide (TMZ) by increasing DNA damage and oxidative stress. GSH activates the nanocapsules, triggering BRD4 degradation and hindering DNA repair. In mouse models, the nanosensitizer, combined with TMZ and X-ray irradiation, efficiently inhibited the growth of GBM. These findings demonstrate a novel PROTAC-based sensitization strategy targeting BRD4, offering a promising approach for effective GBM therapy.

OBJECTIVES: To investigate the effects of quercetin on cuproptosis and L-type calcium currents in the myocardium of diabetic rats. METHODS: Forty SD rats were randomized into control group and diabetic model groups. The rat models of diabetes mellitus (DM) induced by high-fat and high-sugar diet combined with streptozotocin (STZ) injection were further divided into DM model group, quercetin treatment group, and empagliflozin treatment group (n=10). Blood glucose and body weight were measured every other week, and cardiac function of the rats was evaluated using echocardiography. HE staining, Sirius red staining, and wheat germ agglutinin (WGA) analysis were used to observe the changes in myocardial histomorphology, and serum copper levels and myocardial FDX1 expression were detected. In cultured rat cardiomyocyte H9c2 cells with high-glucose exposure, the effects of quercetin and elesclomol, alone or in combination, on intracellular CK-MB and LDH levels and FDX1 expression were assessed, and the changes in L-type calcium currents were analyzed using patch-clamp technique. RESULTS: The diabetic rats exhibited elevated blood glucose, reduced body weight, impaired left ventricular function, increased serum copper levels and myocardial FDX1 expression, decreased L-type calcium currents, and prolonged action potential duration. Quercetin and empagliflozin treatment significantly lowered blood glucose, improved body weight, and restored cardiac function of the diabetic rats, and compared with empagliflozin, quercetin more effectively reduced serum copper levels, downregulated FDX1 expression, and enhanced myocardial L-type calcium currents in diabetic rats. In H9c2 cells, high glucose exposure significantly increased myocardial expressions of FDX1, CK-MB and LDH, which were effectively lowered by quercetin treatment; Elesclomol further elevated FDX1, CK-MB and LDH levels in the exposed cells, and these changes were not significantly affected by the application of quercetin. CONCLUSIONS Quercetin ameliorates myocardial injury in diabetic rats possibly by suppressing myocardial cuproptosis signaling and restoring L-type calcium channel activity.
Animals ; Quercetin/pharmacology* ; Calcium Channels, L-Type/metabolism* ; Diabetes Mellitus, Experimental/metabolism* ; Rats, Sprague-Dawley ; Rats ; Myocytes, Cardiac/drug effects* ; Myocardium/pathology* ; Male

Objective: To investigate the current status of iron metabolism among apheresis donors in Guangzhou and analyze the improvement effects of health education on iron deficiency in frequent apheresis donors. Methods: Using a generalized linear mixed model (GLMM), a 180-day follow-up was conducted on 261 eligible apheresis donors at the Guangzhou Blood Center from January to July 2024. Hemoglobin (Hb), serum ferritin (SF), unsaturated iron-binding capacity (UIBC), total iron-binding capacity (TIBC), and transferrin saturation (TS) were selected as outcome variables. The effects of gender, age group, and number of donations within 180 days on these outcomes were analyzed and modeled. A general linear model (GLM) with repeated measures was applied to 55 donors who received health education interventions, comparing changes in Hb and iron metabolism-related indicators before and after follow-up and health education. Results: No significant difference in Hb levels was observed between first-time and regular apheresis donors, but SF levels were significantly higher in first-time donors (F=6.195, P<0.05). The GLMM revealed that female donors exhibited more significant reductions in Hb (T=-12.546) and SF (T=-5.829)(P<0.05 for both). Age group showed no interactive effects on Hb or SF changes. While number of donations within 180 days had no interactive effect on Hb, SF levels significantly decreased with increased number of donations (using ≥9 donations as the reference group; P<0.05 for all groups). After health education, Hb levels remained unchanged, but SF increased compared to pre-intervention levels (mean difference: -18.571, P<0.05), though a declining trend persisted compared to baseline (mean difference from baseline to post-intervention: 23.068,P<0.05). Conclusion: Female and number of donations are primary factors contributing to SF reduction in apheresis donors. Health education interventions promote SF recovery. Extending donation intervals and reinforcing iron deficiency-related health education may improve iron status in donors.

Objective To analyze the nonlinear relationship between hypothermic machine perfusion (HMP) parameters and delayed graft function (DGF) and optimize the construction of a predictive model for DGF. Methods The data of 923 recipients who underwent kidney transplantation from deceased donors were retrospectively analyzed. According to the occurrence of DGF, the recipients were divided into DGF group (n=823) and non-DGF group (n=100). Donor data, HMP parameters and recipient data were analyzed for both groups. The nonlinear relationship between HMP parameters and the occurrence of DGF was explored based on restricted cubic splines (RCS). Over-sampling, under-sampling and balanced sampling were used to address the imbalance in the proportion of DGF to construct logistic regression predictive models. The area under the curve (AUC) of each model was compared in the validation set, and a nomogram model was constructed. Results Donor BMI, cold ischemia time of the donor kidney, and HMP parameters (initial and final pressures, resistance, and perfusion time) were significantly different between the DGF and non-DGF groups (all P<0.05). The RCS analysis revealed a threshold-like nonlinear relationship between HMP parameters and the risk of DGF. Among the models constructed using different sampling methods, the balanced sampling model had the highest AUC. Using this model, a nomogram was constructed to stratify recipients based on risk scores. Recipients in the high-risk group had higher serum creatinine levels at 1, 6, and 12 months after kidney transplantation compared to those in the low-risk group (all P<0.05). Conclusions There is a nonlinear relationship between HMP parameters and the risk of DGF, and the threshold is helpful for organ quality assessment and monitoring of graft function after transplantation. The predictive model for DGF constructed on the base of balanced sampling algorithms helps perioperative decision-making and postoperative graft function monitoring of kidney transplantation.

[摘 要] 目的：探讨2',4'-二羟基查尔酮（D2）通过调控miR-7-5p诱导自噬，抑制结直肠癌细胞增殖、迁移及上皮间质转化（EMT）的分子机制。方法：选取结直肠癌细胞系HCT-15、SW620为研究对象，分别用不同浓度（0、12.5、25、50 µmol/L）的D2处理细胞，采用MTT法和平板克隆实验检测细胞增殖活力及克隆形成能力，划痕愈合实验及Transwell实验评估细胞迁移能力，WB法检测EMT相关蛋白、自噬相关蛋白及PI3K/AKT/mTOR信号通路蛋白的表达情况，免疫荧光染色法观察自噬小体的形成。基于TCGA数据库分析miR-7-5p在结直肠癌中的表达水平，并借助KEGG富集分析探究miR-7-5p与结直肠癌的关联。运用RT-qPCR检测miR-7-5p的表达量，同时采用慢病毒转染技术构建miR-7-5p稳定敲低或过表达的细胞系。结果：D2抑制结直肠癌细胞的增殖、迁移及EMT进程（P < 0.05或P < 0.01）。TCGA数据库分析及KEGG富集分析显示，miR-7-5p在结直肠癌中呈低表达，且与结直肠癌的发生有密切关联。12.5、25、50 µmol/L D2处理均可上调HCT-15、SW620细胞miR-7-5p的表达水平（均P < 0.01）。25 µmol/L D2处理组HCT-15、SW620细胞中 LC3、p-ULK1等自噬相关蛋白表达增加，而PI3K/AKT/mTOR信号通路受到抑制（均P < 0.05），细胞内自噬小体数量增加（均P < 0.01）；与D2单独处理组相比，经 D2处理的miR-7-5p敲减细胞中LC3、p-ULK表达量有所下降（P < 0.05或P < 0.01）。结论：D2通过调控miR-7-5p诱导自噬，抑制结直肠癌细胞的增殖、迁移及EMT进程，其机制可能与抑制PI3K/AKT/mTOR信号通路有关。