Chronic pain is a complex condition shaped by long-standing alterations in both physiological and psychological processes. Rather than representing a simple continuation of acute nociceptive signaling, chronic pain is increasingly understood as the outcome of progressive dysregulation within distributed neural systems that govern sensation, affect, motivation, and cognitive control. Neuroimaging and electrophysiological studies indicate that this state is accompanied by extensive plastic changes in deep brain structures and large-scale networks. Beyond well-described central sensitization processes, chronic pain is characterized by disrupted oscillatory rhythms and altered connectivity within large-scale brain networks, including thalamo-cortical circuits and prefrontal-limbic-reward networks. These findings support a conceptual shift from viewing chronic pain as a focal, lesion-driven phenomenon toward recognizing it as a disorder of distributed network pathology. Pharmacological treatments remain central to clinical practice, yet their long-term efficacy is often limited and frequently accompanied by substantial side effects. The ongoing concerns about opioid-related risks and the inadequate therapeutic response in a subset of patients highlight the need for safe, non-pharmacological approaches that can address not only pain but also comorbid disturbances in mood, sleep, and social functioning. Neuromodulation provides a promising path toward mechanism-based and non-pharmacological management of chronic pain by employing physical or chemical stimulation to alter the excitability and synchrony of specific neural populations within central, peripheral, and autonomic systems. While invasive deep brain stimulation demonstrates that targeting deep brain structures can be effective, its clinical application is restricted by surgical risks and cost, highlighting the importance of non-invasive techniques capable of reaching deep targets. Current non-invasive approaches, such as transcranial electric stimulation, are constrained by limited penetration depth and insufficient spatial precision. These limitations hinder reliable engagement of deep regions implicated in pain, including the thalamus and nucleus accumbens, and tend to produce broad, non-specific modulation of cross-network oscillatory activity. Temporal interference (TI) stimulation has emerged as a means of overcoming these obstacles. By delivering interacting high-frequency currents that generate a low-frequency envelope within the head, TI enables focal stimulation of deep targets while minimizing superficial current delivery. Recent multiscale modeling and animal studies indicate that TI exploits the nonlinear rectification properties of neuronal membranes in response to high-frequency carriers, as well as their phase-locked responses to low-frequency envelopes, to generate “peak-focused” electric fields in deep regions under relatively low superficial current loads. Moreover, TI appears to exhibit potential advantages in terms of cell-type selectivity and rhythm-specific engagement, including differential responses across neuronal subtypes and distinct coupling to θ-, β-, and γ-band oscillations. These features suggest a promising avenue for correcting abnormal rhythms and network dynamics that contribute to chronic pain. This review summarizes current knowledge of the neural mechanisms underlying chronic pain and recent advances in TI research. It examines functional disturbances across key pain-related regions and networks, outlines the principles and technical characteristics of TI, and discusses potential deep-brain targets and stimulation strategies relevant to chronic pain. Evidence to date indicates that TI, with its non-invasiveness, tolerability, and capacity for precise deep brain modulation, holds great promise for the management of treatment-resistant chronic pain and may evolve into a new generation of precise and efficient non-pharmacological analgesic strategies.

Chronic pain is a complex condition shaped by long-standing alterations in both physiological and psychological processes. Rather than representing a simple continuation of acute nociceptive signaling, chronic pain is increasingly understood as the outcome of progressive dysregulation within distributed neural systems that govern sensation, affect, motivation, and cognitive control. Neuroimaging and electrophysiological studies indicate that this state is accompanied by extensive plastic changes in deep brain structures and large-scale networks. Beyond well-described central sensitization processes, chronic pain is characterized by disrupted oscillatory rhythms and altered connectivity within large-scale brain networks, including thalamo-cortical circuits and prefrontal-limbic-reward networks. These findings support a conceptual shift from viewing chronic pain as a focal, lesion-driven phenomenon toward recognizing it as a disorder of distributed network pathology. Pharmacological treatments remain central to clinical practice, yet their long-term efficacy is often limited and frequently accompanied by substantial side effects. The ongoing concerns about opioid-related risks and the inadequate therapeutic response in a subset of patients highlight the need for safe, non-pharmacological approaches that can address not only pain but also comorbid disturbances in mood, sleep, and social functioning. Neuromodulation provides a promising path toward mechanism-based and non-pharmacological management of chronic pain by employing physical or chemical stimulation to alter the excitability and synchrony of specific neural populations within central, peripheral, and autonomic systems. While invasive deep brain stimulation demonstrates that targeting deep brain structures can be effective, its clinical application is restricted by surgical risks and cost, highlighting the importance of non-invasive techniques capable of reaching deep targets. Current non-invasive approaches, such as transcranial electric stimulation, are constrained by limited penetration depth and insufficient spatial precision. These limitations hinder reliable engagement of deep regions implicated in pain, including the thalamus and nucleus accumbens, and tend to produce broad, non-specific modulation of cross-network oscillatory activity. Temporal interference (TI) stimulation has emerged as a means of overcoming these obstacles. By delivering interacting high-frequency currents that generate a low-frequency envelope within the head, TI enables focal stimulation of deep targets while minimizing superficial current delivery. Recent multiscale modeling and animal studies indicate that TI exploits the nonlinear rectification properties of neuronal membranes in response to high-frequency carriers, as well as their phase-locked responses to low-frequency envelopes, to generate “peak-focused” electric fields in deep regions under relatively low superficial current loads. Moreover, TI appears to exhibit potential advantages in terms of cell-type selectivity and rhythm-specific engagement, including differential responses across neuronal subtypes and distinct coupling to θ-, β-, and γ-band oscillations. These features suggest a promising avenue for correcting abnormal rhythms and network dynamics that contribute to chronic pain. This review summarizes current knowledge of the neural mechanisms underlying chronic pain and recent advances in TI research. It examines functional disturbances across key pain-related regions and networks, outlines the principles and technical characteristics of TI, and discusses potential deep-brain targets and stimulation strategies relevant to chronic pain. Evidence to date indicates that TI, with its non-invasiveness, tolerability, and capacity for precise deep brain modulation, holds great promise for the management of treatment-resistant chronic pain and may evolve into a new generation of precise and efficient non-pharmacological analgesic strategies.

ObjectiveTo investigate the role of interleukin （IL）-17A in acute inhalational pneumonia induced by the highly drug-resistant and hypervirulent Staphylococcus aureus strain USA300-R in mice. MethodsAn acute inhalational pneumonia model was established in mice using an aerosolized pulmonary delivery technique. RNA sequencing （RNA-seq） and enzyme-linked immunosorbent assay （ELISA） were employed to examine the expression dynamics of Il17a mRNA and IL-17A protein， respectively， in the lungs of infected mice. Il17a knockout （Il17a^-/-） mice were generated using CRISPR/Cas9 gene editing technology. The survival rate， body weight， bacterial load in lung tissue， and histopathological changes were compared between Il17a^-/- and wild-type （WT） mice following inhalational infection with USA300-R. Results12 hours after USA300-R infection， compared to pre-infection， the expression level of Il17a mRNA in lung tissue and the level of IL-17A protein in bronchoalveolar lavage fluid （BALF） increased by approximately 50-fold （P<0.01） and 6-fold （P<0.001）， respectively. Compared to WT mice， Il17a^-/- mice exhibited approximately 10-fold higher bacterial loads in lung tissue at both 12 and 24 hours post-infection （P<0.001， P<0.05）. However， they showed significantly attenuated lung histopathological injury， reduced alveolar wall thickening， markedly decreased neutrophil infiltration， and an approximately 50% improvement in survival rate （P<0.05）. ConclusionIn acute Staphylococcus aureus USA300-R inhalational pneumonia， IL-17A contributes to bacterial clearance by recruiting neutrophils； however， excessive neutrophil infiltration exacerbates pulmonary inflammation and injury， reduces survival rates， and represents a potential therapeutic target.

Objective To compare the long-term prognosis differences between surgical radical resection and endoscopic resection for early gastric cancer patients based on the SEER database. Methods A total of 1 437 patients with stage Tis to T_1b gastric adenocarcinoma were selected from the SEER database from January 1, 2004 to December 31, 2013. They were divided into a surgery group (n=1 257) and an endoscope group (n=180) according to the treatment method. Kaplan-Meier survival curve and Cox regression model were used to analyze survival outcomes. Results The patients in the surgery group were younger than those in the endoscope group ([67.63±12.97] years old vs [71.29±10.82] years old), with higher rates of T₁ stage (97.45% vs 87.78%) and lymph node metastasis (19.73% vs 5.00%, all P＜0.001). The median follow-up time for all patients was 37 (15, 66) months, and the mortality rate of gastric cancer in the endoscope group was lower than that in the surgery group (23.33% vs 27.13%, P＜0.001). Univariate Cox analysis showed that treatment modality, age, sex, T stage, lymph node metastasis were all associated with early gastric cancer mortality (all P＜0.05), and the risk of death in the endoscope group was 43% of that in the surgery group (HR=0.43, P=0.015). After adjusting for multiple factors, there was no statistically significant difference in mortality risk between the two groups (P=0.067), but after excluding lymph node positive patients, the mortality risk in the endoscope group was 46% of that in the surgery group (HR=0.46, P=0.048). Conclusions For early gastric cancer patients with negative lymph nodes, endoscopic resection may provide better survival benefits than surgical procedures, suggesting that it can be the preferred treatment strategy for patients with low risk of lymph node metastasis.

Objective To observe the difference of bone micro-structure in different regions of proximal femur,micro-CT scanning was performed on 30 proximal femur specimens to explain the mechanism of proximal femur fracture and to provide anatomical basis for prosthesis design.Methods Totally 30 intact proximal femur specimens were obtained from 60-80 year-old cadavers.Micro-CT scanning was used to measure the trabecular thickness(Tb.Th),trabecular number(Tb.N),trabecular space(Tb.Sp),connectivity(Conn)and bone mineral density(BMD)and other parameters in 7 regions of proximal femur,including proximal pressure trabecular(PPT),distal pressure trabecular(DPT),femoral head-neck junction(FHNJ),head and neck of femoral neck(HNFN),the base of femoral neck(BPFN),intertrochanteric line(IL)and greater trochanter(GT).Results The bone mineral density of IL and GT were higher than those of BPFN,FHNJ,DPT and PPT.The trabecular thickness of GT was the largest,followed by IL,BPFN and HNFN,and the smallest was FHNJ,DPT and PPT.The trabecular space of IL was larger than that of GT,and the data of both were larger than those of other parts,among which DPT and PPT were the smallest.The trabecular number of IL and GT were the smallest,BPFN,HNFN and FHNJ were larger,and DPT was the largest.The volume fraction of IL was the smallest,BPFN and HNFN were larger,DPT and PPT were the largest.Conclusion The bone density,trabecular thickness,bone volume,and total volume of GT and IL in the proximal femur of elderly patients are all relatively large,so the reason for the high incidence of fractures is not due to weak internal bone microstructure;The bone density,trabecular thickness,and trabecular gap at the proximal and distal ends of the vertical trabecular bone are relatively small.If it is necessary to perform core decompression for prosthesis filling at this location,the design should be conducive to the mechanical conduction of the prosthesis and the regeneration of surrounding bone tissue.

Objective To investigate the types and mechanisms of microglial cell death induced by interaction between palmitic acid(PA)and lipopolysaccharide(LPS).Methods BV-2 microglial cells were divided into three groups for apoptosis research,BSA group,PA treatment group,and staurosporine(STA)group.They were further divided into four groups for necrosis research,BSA group,BSA+inhibitor group,PA group,and PA+inhibitor group.Western blotting was conducted to assess the expression levels of key proteins involved in apoptosis and necrosis pathways.The effect of PA on microglial cells was validated through feeding a high-fat diet to Institute of Cancer Research(ICR)mice.Results Apoptotic microglia were observed in both BSA group and PA group,PA significantly induced the activation of caspase-3,caspase-7,and poly ADP-ribose polymerase(PARP).However,compared to the BSA group,the level of activated Caspase-7 in the STA group did not change significantly.Inhibition of ferroptosis,necroptosis,or autophagy did not protect against PA-induced cell damage,while the Caspase-11 inhibitor,wedelolactone(WE),significantly improved PA induced cell damage.This study also found that PA could promote LPS entry into microglial cells and induce pyroptosis.This phenomenon and the protective effect of WE were further confirmed in a high-fat diet mouse model through immunofluorescent staining and Western blotting.Conclusion PA induces apoptosis and pyroptosis in microglial cells,while simultaneously promoting LPS entry into microglial cells and inducing pyroptosis.

Objective To establish a human intestinal organ-on-a-chip model using a multi-array chip array to simulate the microphysiological structure of the human intestine and to investigate the impact of ionizing radiation on radiation-induced damage to human intestinal cells.Methods Caco-2 and human umbilical vein endothelial cells(HUVECs)were co-cultured in an organ chip.The cells were subjected to fluid shear stress via a precision shaker.After 7 days of dynamic culture,the morphological structure of intestinal epithelial cells and venous endothelial cells within the intestinal organ chip was examined using phase contrast microscopy,immunofluorescence staining,and confocal microscopy for three-dimensional(3D)imaging.γ-H2AX and TUNEL immunofluorescence staining were employed to assess DNA damage and apoptosis in intestinal epithelial cells two days post-irradiation.Villin immunofluorescence staining was used to evaluate villus height three days post-irradiation.EdU incorporation assay and Ki67 immunofluorescence staining were conducted to observe the effects of ionizing radiation on the proliferation of intestinal epithelial cells.Results After 7 days of dynamic culture,phase contrast microscopy and immunofluorescence staining combined with confocal 3D imaging revealed that the upper intestinal epithelial cells in the middle compartment of the chip formed a 3D intestinal villus structure,while the vascular endothelial cells in the lower compartment developed a vascular network structure.The chip was subsequently irradiated by 10 Gy X-ray.Immunofluorescence staining results indicated that the mean fluorescence intensity of γ-H2AX and TUNEL in the irradiated group was significantly higher than in the non-irradiated group 2 days after irradiation(P＜0.01),and that the proportion of EDU+and Ki67+cells in the irradiated group was significantly lower than in the non-irradiated group three days after irradiation(P＜0.05).Conclusion Caco-2 cells and HUVECs co-culture on an organ chip can generate the biomimetic structure of human intestinal villus.Ionizing radiation has been found to shorten intestinal villus,increase DNA damage and apoptosis in intestinal epithelial cells,and inhibit the proliferation of these cells.

AIM To investigate the effects of Heixiaoyao Powder on neuroinflammation in APP/PS1 transgenic mice.METHODS The 16-week-old male APP/PS1 transgenic mice were randomly divided into the model group,the BBG group(P2X7R specific antagonist,30 mg/kg)and high,medium and low dose Heixiaoyao Powder groups of(22.10,11.05,5.53 g/kg),in contrast to the male C57BL/6J mice of the same age and the same strain of the blank groups,with 12 mice in each group.When normal saline by gavage was dosed upon the blank group and the model group,and the other groups were treated with corresponding drug by gavage.After 90 days of administration,the mice had their learning and memory ability detected by Morris water maze test;their hippocampal pathological changes observed with HE staining;their MyD88 expression detected by immunofluorescence staining;their hippocampal levels of pro-inflammatory factors(TNF-α,IL-6),anti-inflammatory factors(IL-10),ATP and amyloid protein β(Aβ)detected by ELISA;their hippocampal mRNA expressions of P2X7R,TLR4,MyD88 and NF-κB-P65 detected by RT-qPCR method;and their hippocampal protein expressions of P2X7R,TLR4,MyD88,NF-κB-P65 and p-NF-κB-P65 detected by Western blot.RESULTS Compared with the blank group,the model group demonstrated prolonged escape latency and reduced frequency in crossing platform(P＜0.01);decreased number of hippocampal neurons,deranged neurons,and darker cytoplasm staining;increased immunofluorescence expression of hippocampal MyD88(P＜0.01);decreased IL-10 level(P＜0.01);increased levels of TNF-α,IL-6,ATP and Aβ(P＜0.01);increased mRNA and protein expressions ofP2X7R,TLR4 and MyD88(P＜0.01),and increased protein expression of p-NF-κB-P65(P＜0.01).Compared with the model group,the groups intervened with Heixiaoyao Powder or BBG demonstrated shortened escape latency and increased frequency in crossing platform(P＜0.01);more number of neatly arranged hippocampal neurons;increased hippocampal IL-10 level(P＜0.01),decreased levels of TNF-α,IL-6,ATP and Aβ(P＜0.05,P＜0.01);decreased mRNA and protein expressions of P2X7R,TLR4 and MyD88(P＜0.05,P＜0.01);and decreased protein expression of p-NF-κB-P65(P＜0.05,P＜0.01).Except the low dose Heixiaoyao Powder group,the other treatment groups shared decreased immunofluorescence expression of MyD88(P＜0.05,P＜0.01).CONCLUSION Heixiaoyao Powder can significantly improve the learning and memory ability of APP/PS1 model mice,and its mechanism may lie in its function in alleviating cerebral neuroinflammation by reducing the abnormal Aβ aggregation via inhibiting the activation of ATP/P2X7R/NF-κB signaling pathway.

OBJECTIVE: To explore the effectiveness of arthroscopic release of elbow joint assisted by medial small incision ulnar nerve release in the treatment of non-traumatic elbow stiffness. METHODS: The clinical data of 15 patients with non-traumatic elbow stiffness treated with arthroscopic release of elbow joint assisted by medial small incision ulnar nerve release between April 2019 and September 2023 were retrospectively analyzed. There were 6 males and 9 females with an average age of 46 years ranging from 34 to 56 years. The causes included rheumatoid arthritis in 3 cases, gouty arthritis in 2 cases, loose bodies in 3 cases, and elbow osteoarthritis in 7 cases. There were 4 cases with ulnar neuritis and 3 cases with synovial osteochondromatosis. The duration of elbow stiffness ranged from 6 to 18 months, with an average of 10 months. The operation time and intraoperative blood loss were recorded. The effectiveness was evaluated by visual analogue scale (VAS) score, range of elbow motion (maximum flexion, maximum extension, and total flexion and extension), Mayo score, and Hospital for Special Surgery (HSS) elbow score. RESULTS: The operation time was 60-90 minutes, with an average of 65 minutes, and the intraoperative blood loss was 40-100 mL, with an average of 62 mL. All patients were followed up 13-18 months, with an average of 14 months. There was no complication such as vascular and nerve injury, poor wound healing, collateral ligament injury, elbow joint space narrowing, osteophyte proliferation, or loose body formation around the joint. At last follow-up, the elbow range of motion (maximum flexion, maximum extension, and total flexion and extension), VAS score, and Mayo score significantly improved when compared with those before operation ( P<0.05). The HSS elbow score was 85-95, with an average of 92; 12 cases were excellent, 3 cases were good, and the excellent and good rate was 100%. CONCLUSION Arthroscopic release of elbow joint assisted by medial small incision ulnar nerve release is an effective way to treat non-traumatic elbow stiffness, which has the advantages of small trauma, short operation time, and good effectiveness. It can carry out early elbow rehabilitation training and significantly improve elbow function.
Humans ; Male ; Female ; Arthroscopy/methods* ; Adult ; Middle Aged ; Elbow Joint/physiopathology* ; Retrospective Studies ; Range of Motion, Articular ; Treatment Outcome ; Ulnar Nerve/surgery* ; Operative Time

OBJECTIVES: To investigate the effect of monotropein on motor function recovery of mice with spinal cord injury (SCI) and explore the underlying mechanism. METHODS: Forty-five adult female C57BL/6 mice were randomized equally into sham operation group, SCI group, and SCI group with daily intraperitoneal monotropein injection. The mice in the former two groups received daily saline injections. Motor function of the mice was evaluated using BMS scores, slant plate test, and footprint analyses. Pathological changes and neuronal counts in the spinal cord were observed using HE, LFB, and Nissl staining. The biological functions of monotropein were explored using GO and KEGG enrichment analyses. NeuN/cleaved caspase-3 immunofluorescence assay and Western blotting were used to detect neuronal apoptosis in the spinal cord of the mice. In cultured HT22 cells, the effect of monotropein on TNF-α-induced cell apoptosis was evaluated using TUNEL staining and Western blotting. In monotropein-treated HT22 cells and SCI mice, the changes in the PI3K/AKT pathway were examined, and the effect of a PI3K/AKT pathway activator (IGF-1) on HT22 cell apoptosis and motor function recovery of SCI mice were observed. RESULTS: SCI mice with monotropein treatment showed significantly improved motor functions with reduced SCI areas and increased myelin retention and neuron counts in the spinal cord. Bioinformatics analysis suggested a role of PI3K/AKT signaling pathway in mediating the anti-apoptotic effects of monotropein. In SCI mice, monotropein obviously reduced apoptotic neurons, decreased expressions of cleaved caspase-3 and Bax and increased Bcl-2 expression in the spinal cord. In HT22 cells, monotropein significantly inhibited TNF-α-induced apoptosis and PI3K/AKT pathway activation. Treatment with IGF-1 obviously increased apoptosis of HT22 cells and exacerbated locomotor dysfunction in SCI mice. CONCLUSIONS Monotropein promotes motor function recovery in SCI mice by reducing neuronal apoptosis possibly by inhibiting the PI3K/AKT signaling pathway.
Animals ; Spinal Cord Injuries/metabolism* ; Apoptosis/drug effects* ; Signal Transduction/drug effects* ; Mice, Inbred C57BL ; Mice ; Proto-Oncogene Proteins c-akt/metabolism* ; Female ; Phosphatidylinositol 3-Kinases/metabolism* ; Neurons/pathology* ; Recovery of Function