BACKGROUND:Cardiac dysfunction due to spinal cord injury is an important factor of death in patients with spinal cord injury;however,the specific mechanism is still not clear.Therefore,revealing the mechanism of cardiac dysfunction in spinal cord injury patients is of great significance to improve their quality of life and survival rate. OBJECTIVE:To investigate the mechanism of luteolin in improving serum-induced myocardial cell death in spinal cord injury rats. METHODS:Allen's impact instrument was used to damage the spine T9-T11 of male SD rats to establish a spinal cord injury model meanwhile a sham operation group was set as the control group.The serum of rats of each group was collected.H9c2 cells were divided into a blank control group,a sham operated rat serum group,a spinal cord injury rat serum group and a luteolin pretreatment group.The cells in blank control group were only cultured with ordinary culture medium.The cells in the sham operated rat serum group were treated with medium containing 10%serum from sham operated rat.The cells in the spinal cord injury rat serum group were treated with medium containing 10%serum from spinal cord injury rat.The cells in the luteolin pretreatment group were precultured with a final concentration of 20 μmol/L luteolin for 4 hours and then changed to a medium containing 10%rat serum from spinal cord injury rat.After 24 hours of culture,the survival rate of each group of H9c2 cells was measured by CCK-8 assay.Western blot assay was used to detect the expression of autophagy related protein LC3 and p62 in H9c2 cells in each group. RESULTS AND CONCLUSION:Compared with the blank control group,there was no significant change in cell survival rate in the sham operated rat serum group(P>0.05).Compared with the sham operated rat serum group,the cell survival rate(P<0.01)and the expression of LC3 protein(P<0.05)in spinal cord injury rat serum group was significantly reduced,and the expression of p62 protein was significantly increased(P<0.05).Compared with the spinal cord injury rat serum group,the survival rate of cells in the luteolin pretreatment group significantly increased(P<0.000 1);the expression of LC3 protein significantly increased(P<0.05),and the expression of p62 protein significantly decreased(P<0.05).The results indicate that luteolin may improve myocardial cell death induced by serum from rats with spinal cord injury by promoting autophagy.

BACKGROUND:Preliminary clinical observations found that Jiawei Chunze Decoction is an effective formula for clinical treatment of urinary retention after spinal cord injury.Animal experiments have found that the phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt)signaling pathway is closely related to the degree of bladder dysfunction. OBJECTIVE:To further investigate the effects of Jiawei Chunze Decoction on bladder function and PI3K/Akt signaling pathway in rats with urinary retention. METHODS:Sixty female Sprague-Dawley rats were randomly divided into sham operation group,model group,Jiawei Chunze Decoction low-dose group,Jiawei Chunze Decoction high-dose group and agonist group.In the sham operation group,the spinal cord was exposed but not transected.In the other groups,the modified Hassan Shaker spinal cord transection method was used to prepare the model of sacral medullary injury.At 24 hours after modeling,the sham operation group and model group were intragastrically given equal volume of normal saline,Jiawei Chunze Decoction low-dose and high-dose groups were given Jiawei Chunze Decoction granules containing 14.4 and 28.8 g/kg,respectively,via intragastric administration for 4 weeks,and the agonist group was treated with an intraperitoneal injection of PI3K/Akt signaling pathway agonist 740Y-P at a dose of 0.02 mg/kg.After 4 weeks of treatment,the maximum bladder capacity,leakage point pressure and bladder compliance of rats in each group were detected by urine flow dynamics.The minimum bladder contraction tension and frequency of rats in each group were detected by detrusor pull test.The pathological changes of the rat bladder in each group were observed by hematoxylin-eosin staining.The concentrations of GRP78,CHOP and Caspase-12 in serum were detected by ELISA,and the mRNA and protein expressions of PI3K,Akt,GRP78,CHOP and Caspase-12 in bladder tissues were detected by RT-PCR and western blot,respectively. RESULTS AND CONCLUSION:Compared with the sham operation group,the maximum bladder volume,bladder compliance and minimum systolic tension of rats in the model group were increased(P<0.05),and the leakage point pressure and bladder contraction frequency were decreased(P<0.05);serum GRP78,CHOP,and Caspase-12 levels were also increased(P<0.05).The arrangement of bladder epithelial cells in the model group was disordered,and there was monocyte infiltration between cells,tissue edema,and detrusor tract atrophy.The mRNA and protein expressions of PI3K and Akt in bladder tissues were significantly decreased in the model group compared with the sham operation group,while those of GRP78,CHOP and Caspase-12 were increased(P<0.05).Compared with the model group,the maximum bladder volume,bladder compliance and minimum systolic tension of rats were decreased in the Jiawei Chunze Decoction low-dose,high-dose and agonist groups after 4 weeks of intervention(P<0.05),while the leakage point pressure and bladder contraction frequency were increased(P<0.05);serum GRP78,CHOP,Caspase-12 levels were decreased(P<0.05).The bladder epithelial cells in the three intervention groups were distributed evenly,arranged neatly,with less inflammatory cell infiltration and fuller detrusor muscle bundle.Compared with the model group,the mRNA and protein expressions of PI3K and Akt were increased in the three intervention groups,while those of GRP78,CHOP and Caspase-12 were decreased(P<0.05).The Jiawei Chunze Decoction high-dose group was better than the Jiawei Chunze Decoction low-dose group and shared the similar results with the agonist group.To conclude,Jiawei Chunze Decoction can improve the bladder function of rats with urinary retention after spinal cord injury,and the mechanism may be related to reducing the occurrence of endoplasmic reticulum stress in bladder tissue through the PI3K/Akt signaling pathway,and then alleviating apoptosis.

BACKGROUND:Cervical rotation-traction manipulation is effective and safe in the treatment of cervical spondylotic radiculopathy,and has been widely used in clinical work.However,its effects on the biomechanics of cervical vertebra and intervertebral disc and the area of intervertebral foramen have not been systematically clarified. OBJECTIVE:Based on the finite element analysis technique,a relevant research and analysis were carried out to provide digital evidence for the mechanism of effect of cervical rotation-traction manipulation in the treatment of cervical spondylotic radiculopathy. METHODS:The CT image data of a volunteer with no neck diseases were selected as the finite element model material at its left-handed physiological limit position.The initial construction of the finite element model was completed by Mimics 19.0 software,Geomagic Studio 2013 software,Hypermash 14.0 software,and ANSYS Workbench 2020 R2 software,respectively.Based on the literature,the grid division of cervical structure and the assignment of elastic modulus and elastic coefficient were completed.Based on the previous work of the team,the mechanical effects of cervical rotation-traction manipulation were simulated on the model.Effects of cervical rotation-traction manipulation on the mechanical parameters of each vertebral body and intervertebral disc in C3-T1 segment and on the cervical lateral foramen area were analyzed. RESULTS AND CONCLUSION:(1)During cervical rotation-traction manipulation,the stress of bone structure was significantly higher than that of soft tissue such as intervertebral disc.(2)When operating the technique,the stress at the top of each cervical vertebra was higher,the stress at the bottom was lower,and the stress at the facet joint and transverse process was lower.The stress at the top of the intervertebral disc was lower,the stress at the bottom was higher,but the highest point of the intervertebral disc stress was outside the top.(3)In addition,after loading the lifting force,the projected area of the C6/C7 intervertebral foramen increased significantly compared with that before loading.(4)It is indicated that the cervical rotation-traction manipulation has the mechanical characteristics of changing the stress structure of the cervical spine itself,and can expand the C6/7 intervertebral cervical foramen area on the opposite side of the patient's cervical rotation,so as to achieve the purpose of treating cervical spondylotic radiculopathy.

BACKGROUND:Cervical disc herniation can cause pain in the neck and shoulder area,as well as radiating pain in the upper limbs.The incidence rate is increasing year by year and tends to affect younger individuals.Fully understanding the biomechanical characteristics of the cervical spine in adolescents is of great significance for preventing and delaying the onset of cervical disc herniation in this age group. OBJECTIVE:To reconstruct cervical spine models for both healthy adolescents and adolescent patients with cervical disc herniation utilizing finite element analysis techniques,to analyze the motion range of the C1-T1 cervical vertebrae as well as the biomechanical characteristics of the annulus fibrosus,nucleus pulposus,endplates,and the cartilage of the small joints. METHODS:A normal adolescent's cervical spine and an adolescent patient with cervical disc herniation were selected in this study.The continuous scan cervical spine CT raw image data were imported into Mimics 21.0 in DICOM format.The C1-T1 vertebrae were reconstructed separately.Subsequently,the established models were imported into the 3-Matic software for disc reconstruction.The perfected models were then imported into Hypermesh software for meshing of the vertebrae,nucleus pulposus,annulus fibrosus,and ligaments,creating valid geometric models.After assigning material properties,the final models were imported into ABAQUS software to observe the joint motion range of the C1-C7 cervical vertebrae segments under different conditions,and to analyze the biomechanical characteristics of the annulus fibrosus,nucleus pulposus,endplates,and small joint cartilage of each cervical spine segment. RESULTS AND CONCLUSION:(1)In six different conditions,the joint motion range of the C1 vertebra in the cervical spine models of both normal adolescent and adolescent patient with cervical disc herniation was higher than that of the other vertebrae.Additionally,the joint motion range of each cervical spine segment in normal adolescent was greater than that in adolescent patient with cervical disc herniation.(2)In the cervical spine model of normal adolescent,the maximum stress values in the annulus fibrosus and nucleus pulposus were found on the left side during C2-3 flexion conditions(0.43 MPa and 0.17 MPa,respectively).In the cervical spine model of adolescent patient with cervical disc herniation,the maximum stress values were found on the left side during C7-T1 flexion conditions(0.54 MPa and 0.18 MPa,respectively).(3)In the cervical spine model of normal adolescent,the maximum stress value on the endplate was found on the left side of the upper endplate of C3 during flexion conditions(1.46 MPa).In the model of adolescent patient with cervical disc herniation,the maximum stress value on the endplate was found on the left side of the lower endplate of C7 during flexion conditions(1.32 MPa).(4)In the cervical spine model of normal adolescent,the maximum stress value in the small joint cartilage was found in the C2-3 left rotation conditions(0.98 MPa).In adolescent patient with cervical disc herniation,the stress in the small joint cartilage significantly increased under different conditions,especially in C1-2,with the maximum stress found during left flexion(3.50 MPa).(5)It is concluded that compared to normal adolescent,adolescent patient with cervical disc herniation exhibits altered cervical curvature and a decrease in overall joint motion range in the cervical spine.In adolescent with cervical disc herniation,there is a significant increase in stress on the annulus fibrosus,nucleus pulposus,and endplates in the C7-T1 segment.The stress on the left articular cartilage of the C1-2 is notable.Abnormal cervical curvature may be the primary factor causing these stress changes.

BACKGROUND:It has also been confirmed that ferroptosis is closely related to a variety of musculoskeletal diseases,such as rheumatoid arthritis,osteosarcoma,and osteoporosis.The pathophysiological mechanisms of ferroptosis and osteoporosis need to be further studied and elucidated to broaden our understanding of iron metabolism and osteoporosis.It will provide research ideas for the future elucidation of new mechanisms of osteoporosis and the development of new technologies and drugs for the treatment of osteoporosis. OBJECTIVE:To provide an overview of the current status of research on ferroptosis in osteoporosis,to provide a new direction for future research on the specific molecular mechanisms of osteoporosis,and to provide more effective and better options for osteoporosis treatment strategies. METHODS:The first author used the computer to search the literature published from 2000 to 2024 in CNKI,WanFang,VIP,and PubMed databases with search terms"ferroptosis,iron metabolism,osteoporosis,osteoblast,osteoclast,bone metabolism,signal pathway,musculoskeletal,review"in Chinese and English.A total of 68 articles were finally included according to the selection criteria. RESULTS AND CONCLUSION:(1)Ferroptosis is a new type of cell death discovered in recent years,which is usually accompanied by a large amount of iron accumulation and lipid peroxidation during cell death,and its occurrence is iron-dependent.This is distinctly different from several types of cell death that are currently being hotly studied(e.g.,cellular pyroptosis,necrotic apoptosis,cuproptosis,and autophagy).(2)Intracellular iron homeostasis is manifested as a balance between iron uptake,export,utilization,and storage.The body's iron regulatory system includes systemic and intracellular regulation.The main factor of systemic regulation is hepcidin produced by hepatic secretion,and cellular regulation depends on the iron regulatory protein/iron response element system.Of course,intracellular iron homeostasis can be controlled by other factors,such as hypoxia,cytokines,and hormones.(3)Lipid peroxidation causes oxidative damage to biological membranes(plasma membrane and internal organelle membranes),lipoproteins,and other lipid-containing molecules.Polyunsaturated fatty acid-containing phospholipids are important targets of lipid peroxidation.Free polyunsaturated fatty acid is an important substrate for lipid oxidation and can bind to the phospholipid bilayer,leading to over-oxidation and thus triggering lipid apoptosis.(4)Several studies have shown that osteoblasts are overloaded with iron in different ways,resulting in the accumulation of unstable ferrous iron and the generation of reactive oxygen species and lipid peroxides,causing ferroptosis of osteoblasts and ultimately a decrease in bone formation,affecting bone homeostasis and the development of osteoporosis.(5)Osteoclasts are large multinucleated cells formed by the fusion of mononuclear macrophage cell lines or bone marrow mesenchymal stem cells induced by nuclear factor-κB ligand receptor activator,and they have the function of bone resorption.Iron ions can promote osteoclast differentiation and bone resorption through the production of intracellular lipid reactive oxygen species,while iron chelators can inhibit osteoclast formation in vitro and thus affect the occurrence and development of osteoporosis.

BACKGROUND:Targeted therapy based on nuclear transcription factor kappa B signaling pathway to explore neuroinflammation is increasingly worth exploring,and the advantages of Chinese medicine such as many targets,wide range,rich mechanisms,and few side effects have great potential in the treatment of various diseases. OBJECTIVE:Based on the nuclear transcription factor kappa B signaling pathway,this paper systematically expounded and summarized the research progress of kaempferol,safflower yellow,baicalin,and triptolide in the treatment of neuroinflammation after spinal cord injury. METHODS:Search terms"spinal cord injury,inflammation,anti-inflammatory,traditional Chinese medicine monomer,monomeric compound,NF-κB signaling pathway,flavonoids,glycosides,phenols,esters,alkaloids"were searched in CNKI and PubMed databases.Totally 67 articles were finally included. RESULTS AND CONCLUSION:(1)The role of nuclear transcription factor kappa B signaling pathway in the nervous system is complex and diverse,which can regulate neutrophils,microglia,astrocytes,and macrophages,and mediate the occurrence and development of inflammation after injury.(2)The effects of traditional Chinese medicine monomers such as baicalin on the degradation of nuclear transcription factor kappa B inhibitory protein,the inhibition of phosphorylation process by safflowerin on nuclear transcription factor kappa B signaling pathway,and the inhibition of kaempferol on nuclear transcription factor kappa B signaling pathway p65 nuclear translocation can reduce the impact of inflammatory response on the body,thereby promoting the recovery of neurological function.(3)The nuclear transcription factor kappa B signaling pathway can promote inflammation and immune cell migration and activation in the early stage of injury,and can promote the repair of injury site and the occurrence of fibrosis in the middle and late stages of injury.Appropriate activation of the nuclear transcription factor kappa B signaling pathway can promote the release of inflammatory factors,improve the antioxidant capacity of cells,and promote the activation of immune cells,but the over-activated nuclear transcription factor kappa B signaling pathway can easily lead to the occurrence and continuation of chronic inflammation and the inhibition of apoptosis.(4)Future research can further explore how to accurately regulate the activation level of nuclear transcription factor kappa B signaling pathway,how to achieve precise intervention for nervous system inflammation and injury,and can also focus on the preparation of traditional Chinese medicine monomers and the mechanism of action of traditional Chinese medicine monomers on signaling pathways,in order to provide more effective treatment strategies for the rehabilitation and functional recovery of neurological diseases.

BACKGROUND:Ossification of the ligamentum flavum was previously considered to be rare in the population.As research has progressed,its incidence rate is increasing gradually,which has aroused the interest of a large number of researchers. OBJECTIVE:To visualize and analyze the research results on ossification of the ligamentum flavum from the Web of Science Core Collection since 1999 using bibliometric methods,and to review the research history of ossification of the ligamentum flavum,highlighting important literature,summarizing research hotspots,and providing ideas for researchers to find research directions. METHODS:Using the Web of Science Core Collection as the data source,relevant papers on ossification of the ligamentum flavum were searched and screened.VOSviewer 1.6.19 and CiteSpace 6.2.R6 were used to conduct the visual analysis of annual publication volume,research countries,institutions,citations,journals,authors,and keywords. RESULTS AND CONCLUSION:(1)A total of 347 papers were included.Since 1999,the number of published papers has increased in a spiral pattern.China's research started later than Japan's,but the number of publications has come up later,with Peking University being the institution with the most publications,and Prof.Chen Zhongqiang from Peking University being the scholar with the most publications.(2)Five of the 10 most frequently cited publications were related to the surgical treatment of the disease.(3)Excluding keywords directly related to the research topic and synthetically analyzing frequencies and betweenness centralities of key words,terms such as"thoracic myelopathy,""dural ossification,""minimally invasive surgery,"and"ossification of the posterior longitudinal ligament"occupied a central position in this field.(4)Keywords clustering analysis showed that clinical manifestations and surgical treatment of ossification of the ligamentum flavum accounted for a large proportion of study.(5)The timeline and burst analysis of keywords revealed that"minimally invasive surgery"appeared as a keyword around 2015,with the highest burst strength and the latest burst start time,and began to receive extensive attention from researchers in 2019.The burst of the keyword"dural ossification"has not yet ended.(6)Surgical treatment for ossification of the ligamentum flavum has been at the forefront of research.Development and research of minimally invasive surgery and research on dural ossification secondary to ossification of the ligamentum flavum are both current research hotspots and possible future research trends.

BACKGROUND:Crosslinked sodium hyaluronate gel has good mechanical property,biocompatibility,and biodegradability,and can be used as an isolated protective material in tumor radiation therapy to protect endangered organs from damage caused by excess radiation dose. OBJECTIVE:To investigate the safety and efficacy of crosslinked sodium hyaluronate gel in reducing the dose of radiation to dangerous organs during brachytherapy. METHODS:A total of 16 specific pathogen-free Kunming mice of the same age and similar body weight were selected as experimental subjects and divided into experimental group and control group by the random number table method,with 8 mice in each group.125I seeds were implanted subcutaneously in the back of mice in the experimental group,and then crosslinked sodium hyaluronate gel was injected around the radioactive particles.Only 125I seeds were implanted subcutaneously in the back of mice in the control group.After injection,the distance between the radioactive particles and the epidermis was measured by spiral CT scan,and the surface radiation dose was measured by radiation dosimeter.Within 10 weeks after injection,the growth state,survival rate,skin radiation damage,and gel retention of mice were observed. RESULTS AND CONCLUSION:(1)Spiral CT scan showed that the implanted gel was relatively concentrated and created an effective distance between the radioactive seeds and the epidermis.The body surface radiation dose of the experimental group was significantly lower than that of the control group(P<0.01).(2)During the experimental observation period,mice in both groups survived;mice in the control group showed obvious irritability and other unstable behavior in the late experimental period,and some mice in the experimental group showed similar behavior.The daily food intake of mice in the two groups had no significant change,and the body mass showed the same increasing trend.After implantation of radioactive seeds,the two groups of mice showed different degrees of radioactive skin injury.From day 23 after injection to the end of the experiment,the skin radiation injury score of the experimental group was lower than that of the control group(P<0.01).At week 10 after implantation,6 mice in the experimental group had no obvious gel residue under their skin,and 2 mice had a very small amount of scattered gel-like samples under their skin.(3)Therefore,the crosslinked sodium hyaluronate injection technique can increase the space between the radioactive target area of 125I seeds and the organ at risk outside the target through physical space occupying,which can effectively reduce the dose of the organ at risk,and play a role in the isolation and protection of the organ at risk.

BACKGROUND:Gradient artificial bone repair scaffolds can mimic unique anatomical features in musculoskeletal tissues,showing great potential for repairing injured musculoskeletal tissues. OBJECTIVE:To review the latest research advances in gradient artificial bone repair scaffolds for tissue engineering in the musculoskeletal system and describe their advantages and fabrication strategies. METHODS:The first author of the article searched the Web of Science and PubMed databases for articles published from 2000 to 2023 with search terms"gradient,bone regeneration,scaffold".Finally,76 papers were analyzed and summarized after the screening. RESULTS AND CONCLUSION:(1)As an important means of efficient and high-quality repair of skeletal system tissues,gradient artificial bone repair scaffolds are currently designed bionically for the natural gradient characteristics of bone tissue,bone-cartilage,and tendon-bone tissue.These scaffolds can mimic the extracellular matrix of native tissues to a certain extent in terms of structure and composition,thus promoting cell adhesion,migration,proliferation,differentiation,and regenerative recovery of damaged tissues to their native state.(2)Advanced manufacturing technology provides more possibilities for gradient artificial bone repair scaffold preparation:Gradient electrospun fiber scaffolds constructed by spatially differentiated fiber arrangement and loading of biologically active substances have been developed;gradient 3D printed scaffolds fabricated by layered stacking,graded porosity,and bio-3D printing technology;gradient hydrogel scaffolds fabricated by in-situ layered injections,simple layer-by-layer stacking,and freeze-drying method;and in addition,there are also scaffolds made by other modalities or multi-method coupling.These scaffolds have demonstrated good biocompatibility in vitro experiments,were able to accelerate tissue regeneration in small animal tests,and were observed to have significantly improved histological structure.(3)The currently developed gradient artificial bone repair scaffolds have problems such as mismatch of gradient scales,unclear material-tissue interactions,and side effects caused by degradation products,which need to be further optimized by combining the strengths of related disciplines and clinical needs in the future.

BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.