This study was aimed to estimate the effect of different ProDisc-C arthroplasty designs after it was implanted to C5-C6 cervicalspine. Finite element (FE) model of intact C5-C6 segments including the vertebrae and disc was developed and validated. Ball-and-socket artificial disc prosthesis model (ProDisc-C, Synthes) was implanted into the validated FE model and the curvature of the ProDisc-C prosthesis was varied. All models were loaded with compressed force 74 N and the pure moment of 1.8 Nm along flexion-extension and bilateral bending and axial torsion separately. The results indicated that the variation in the curvature of ball and socket configuration would influence the range of motion in flexion/extension, while there were not apparently differences under other conditions of loads. The method increasing the curvature will solve the stress concentration of the polyethylene, but it will also bring adverse outcomes, such as facet joint force increasing and ligament tension increasing. Therefore, the design of artificial discs should be considered comprehensively to reserve the range of motion as well as to avoid the adverse problems, so as not to affect the long-term clinical results.
Arthroplasty ; Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Intervertebral Disc ; Pressure ; Prostheses and Implants ; Range of Motion, Articular ; Spine ; Zygapophyseal Joint

We observed the effect of vibration parameters on lumbar spine under different vibration conditions using finite element analysis method in our laboratory. In this study, the CT-images of L1-L5 segments were obtained. All images were used to develop 3D geometrical model using the Mimics10. 01 (Materialise, Belgium). Then it was modified using Geomagic Studio12. 0 (Raindrop Geomagic Inc. USA). Finite element (FE) mesh model was generated by Hypermesh11. 0 (Altair Engineering, Inc. USA) and Abaqus. Abaqus was used to calculate the stress distribution of L1-L5 under different vibration conditions. It was found that in a vibration cycle, tensile stress was occurred on lumbar vertebra mainly. Stress distributed evenly and stress concentration occurred on the left rear side of the upper endplate. The stress had no obvious changes under different frequencies, but the stress was higher when amplitude was greater. In conclusion, frequency and amplitude parameters have little effect on the stress distribution in vertebra. The stress magnitude is positively correlated with the amplitude.
Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Lumbar Vertebrae ; physiology ; Vibration

OBJECTIVE: To analyze the difference in gene expression profiles and screen silicosis development related differentially expressed genes(DEGs) and signaling pathways in peripheral blood specimens of rats exposed to silica dust using bioinformatics and gene chip. METHODS: GSE27023 gene expression profiles of peripheral blood samples of rats exposed to silica dust were downloaded from Gene Expression Omnibus database. After screening of the DEGs through paired-sample t-test and fold change method,DEGs related to rats exposed to silica dust was performed by Gene Ontology functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. The protein-protein interaction(PPI) network was constructed with the Search Tool for the Retrieval of Interacting Genes database and visualized using the software Cytoscape. RESULTS: Of the 2 767 DEGs screened,1 363 were up-regulated and1 404 were down-regulated. KEGG pathway enrichment analysis showed that 39 signaling pathways,such as the calcium signaling pathway,neuroactive ligand-receptor interaction,Ras-related protein 1 signaling pathway,were significantly enriched. DEGs enrichment and significance reached the highest level in the calcium signaling pathway. PPI network and module analysis suggested that mitogen-activated protein kinase 14(Mapk14),DNA-directed RNA PolymeraseⅡ,V-erb-a erythroblastic leukemia viral oncogene homolog 4,B-cell lymphoma-2(Bcl-2),receptor interacting serine/threonine kinase 4,PH domain leucine-rich repeat protein phosphatase 2,DNA-directed RNA polymerase Ⅲ,neurogenic locus notch homolog protein 1,histone deacetylase 1,yeast switch in mating type/Sucrose non fermentation related,matrix associated,actin dependent regulator of chromatin,subfamily a,member 4 were top 10 hub-proteins. Mapk14 had the highest node degree in up-regulated DEGs,and Bcl-2 had the highest node degree in down-regulated DEGs. CONCLUSION: We found 39 signaling pathways and 10 DEGs that are related to toxicity caused by exposure to silica dust in rats by analysis of peripheral blood gene chip data. Among them,calcium signaling pathway,Mapk14 and Bcl-2 may play important roles in the development and progress of silicosis in rats.

OBJECTIVE: To explore the molecular mechanism of curcumin in inhibiting the nucleotide-binding oligomerization domain like receptor family pyrin domain-containing(NLRP3) inflammatory bodies induced by silica(SiO_2) in mouse alveolar macrophages(AM). METHODS: AMs were isolated from the bronchoalveolar lavage fluid of specific pathogen free C57 BL/6 mice and divided into 6 groups. Among them, the AM of the control group received no stimulation; the AM in the SiO_2 stimulation group was stimulated with SiO_2 suspension at the final mass concentration of 50 mg/L; the AM in nuclear factor(NF-κB)inhibition group was pretreated with 5-(4-fluorophenyl)-2-urea-thiophene-3-formamide with a final concentration of 200 nmoL/L for 1 hour, the AM in the low-, medium-and high-dose curcumin groups were pretreated with curcumin with the final concentrations of 20, 40 and 50 μmol/L for 1 hour, respectively, and then stimulated with SiO_(2 )suspension with a final concentration of 50 mg/L. Samples were collected after 6 hours of incubation. The mRNA expression of NLRP3 inflammasome related genes such as NLRP3, Caspase-1 and interleukin(IL)-1β was detected by real-time fluorescence quantitative polymerase chain reaction. The secretion level of maturation IL-1β(mIL-1β) and IL-18 in AM was detected by enzyme-linked immunosorbent assay. The protein expression and secretion level of cleaved Caspase-1, precursor-IL-1β(pro-IL-1β) and mIL-1β were analyzed by Western blotting. RESULTS: The mRNA relative expression of NLRP3, Caspase-1 and IL-1β, and the secretion levels of mIL-1β and IL-18, and the protein relative expression of Caspase-1, pro-IL-1β and mIL-1β, as well as the secretion levels of cleaved Caspase-1 and mIL-1β increased in the SiO_2 stimulated group compared with the control group(P<0.05). Except for the relative expression and the secretion level of cleaved Caspase-1, the other 8 indexes in the NF-κB inhibition group were lower than that in the SiO_2 stimulation group(P<0.05). Except for the relative expression of cleaved Caspase-1 and mIL-1β proteins in the low-dose curcumin group, the relative expression of all the above 10 indexes was lower in the three curcumin treated groups than that in the SiO_2 stimulation group(P<0.05). In addition, all the above indexes decreased with the increase of curcumin intervention dose(P<0.05). The mRNA relative expression of NLRP3 and IL-1β, and the protein relative expression of pro-IL-1β increased in the medium-dose curcumin group(P<0.05), the secretion levels of mIL-1β and IL-18, as well as the protein relative expression and secretion levels of cleaved Caspase-1 and mIL-1β decreased(P<0.05), compared with the NF-κB inhibition group. CONCLUSION: Curcumin can inhibit SiO_2-induced AM NLRP3 inflammasome activation in a dose-response relationship. This process may be related to the inhibition of NF-κB signaling pathway by curcumin and the down-regulating NLRP3 inflammasome-related genes at the transcriptional level. The important mechanism may be that curcumin directly blocks the activation, assembly, and downstream shearing of NLRP3 in inflammasomes.

Objective To evaluate the relationship between perioperative peripheral blood Type 17 helper (Th17) cells and Th17-related cytokines and postoperative cognitive dysfunction (POCD) in elderly patients undergoing general anesthesia.Methods Ninety-six patients of both sexes,aged 65-86 yr,of American Society of Anesthesiologists physical status Ⅱ or m,scheduled for elective hip replacement under general anesthesia,were selected.At 3 days before operation and 1,2,3 and 7 days after operation,Montreal Cognitive Assessment (MoCA) was used to evaluate the cognitive function,and fasting venous blood samples were taken for determination of the percentage of Th17 cells and serum interleukin-17 (IL-17) and IL-22 concentrations.The patients were divided into POCD group and non-POCD group according to whether the patients developed POCD at day 7 after operation or not.Pearson linear correlation of the percentage of Th17 cells and serum IL-17 and IL-22 concentrations with MoCA scores was analyzed.Results Twenty-six patients developed POCD (27.1％).The percentage of peripheral blood Th17 cells and serum IL-17 and IL-22 concentrations were significantly higher at each time point after operation than before operation in POCD group and at 1 and 2 days after operation than before operation in non-POCD group (P＜0.05).The percentage of peripheral blood Th17 cells and serum IL-17 and IL-22 concentrations were significantly higher at each time point after operation in POCD group than in non-POCD group (P＜0.05).The percentage of peripheral blood Thl7 cells was negatively correlated with MoCA scores (r =-0.867,P＜0.01) and serum IL-17 and IL-22 concentrations were negatively correlated with MoCA scores (r=-0.662 and-0.638,P＜0.01) in group POCD.Conclusion The development of POCD is related to the increase in the percentage of peripheral blood Th17 cells and concentrations of Th17-related cytokines IL-17 and IL-22 in elderly patients undergoing general anesthesia.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

The acute combination fractures of the atlas and axis in adults have a higher rate of neurological injury and early death compared with atlas or axial fractures alone. Currently, the diagnosis and treatment choices of acute combination fractures of the atlas and axis in adults are controversial because of the lack of standards for implementation. Non-operative treatments have a high incidence of bone nonunion and complications, while surgeries may easily lead to the injury of the vertebral artery, spinal cord and nerve root. At present, there are no evidence-based Chinese guidelines for the diagnosis and treatment of acute combination fractures of the atlas and axis in adults. To provide orthopedic surgeons with the most up-to-date and effective information in treating acute combination fractures of the atlas and axis in adults, the Spinal Trauma Group of Orthopedic Branch of Chinese Medical Doctor Association organized experts in the field of spinal trauma to develop the Evidence-based guideline for clinical diagnosis and treatment of acute combination fractures of the atlas and axis in adults ( version 2023) by referring to the "Management of acute combination fractures of the atlas and axis in adults" published by American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons (CNS) in 2013 and the relevant Chinese and English literatures. Ten recommendations were made concerning the radiological diagnosis, stability judgment, treatment rules, treatment options and complications based on medical evidence, aiming to provide a reference for the diagnosis and treatment of acute combination fractures of the atlas and axis in adults.

Objective: To observe the repairing effect of adipose mesenchymal stem cells (ADSCs) on lung injury induced by silica in rats. Methods: Primary ADSCs-GFP was obtained from rats. ADSCs-GFP was injected into tail vein of silicosis model rats. The expression of green fluorescence in lungs was observed regularly to determine the homing ability of ADSCs. Primary ADSCs of rats were obtained and randomly divided into control group, exposure group, vehicle group and ADSCs group. Silicosis rat model was established by non-exposed tracheal drip method. 24 hours after silica exposure, rats in ADSCs group were injected with ADSCs of 1×10⁶/kg body weight through tail vein, and the pathological changes of lung tissue were observed and evaluated 28 days after intervention. To explore the early intervention mechanism of ADSCs on pulmonary fibrosis in silicosis model rats, apoptosis-related proteins were detected by immunohistochemistry. Results: 28 days after exposure to silica, rats in the exposure group showed obvious pulmonary fibrosis. Compared with exposure group and vehicle group, ADSCs group showed less pulmonary inflammation, less silica nodules and less collagen deposition area. Immunohistochemical results showed that the expression of Caspase-3 and cytochrome C protein decreased and Bcl-2 protein increased after ADSCs transplantation. Conclusion ADSCs infusion has an obvious intervention effect on postponing early silicosis fibrosis in rats exposed to silica, and its mechanism is related to the regulation of apoptotic process.