Objective: To evaluate the performance of 5T magnetic resonance imaging (MRI) in visualizing dental pulp and periodontal ligament (PDL) tissues in vivo in the young adult population, thereby providing a basis for the application of high-field MRI technology in clinical oral examinations. Methods: The study was approved by the Ethics Committee of the hospital. A total of 15 healthy volunteers (413 permanent teeth altogether) were recruited and underwent full-mouth 5T MRI scans. Among them, six volunteers (168 permanent teeth) also received both 3T MRI and cone-beam computed tomography (CBCT) scans. Two dental specialists independently evaluated the imaging quality of the dental pulp and PDL on the images using a 5-point Likert scale and recorded the number of detectable root canals for each tooth. Inter-rater agreement was assessed using weighted kappa statistics and intraclass correlation coefficient (ICC). Non-parametric tests were employed to compare differences in imaging performance among different tissue structures, tooth positions, and imaging modalities. Results: 5T MRI can achieve in vivo imaging for most dental pulp tissues and partial periodontal membrane structures. There was a high level of agreement between the two raters in their imaging scores for the dental pulp and PDL (dental pulp κ = 0.934, PDL κ = 0.737). The imaging scores for dental pulp were significantly higher than those for PDL (P < 0.001), and the scores for molar dental pulp were lower than those for premolars and anterior teeth. In the multimodal comparison involving six volunteers, the raters showed good consistency in scoring dental pulp and PDL imaging across 5T MRI, 3T MRI, and CBCT, as well as in root canal counts (5T MRI for dental pulp κ = 0.971, 3T MRI for dental pulp κ = 0.933, CBCT for dental pulp κ = 0.964; 5T MRI for PDL κ = 0.625, 3T MRI for PDL κ = 0.667, CBCT for PDL κ = 0.571; ICC for root canal counts all ≥ 0.990). The imaging scores for dental pulp and PDL using 5T MRI were significantly higher than those using 3T MRI (dental pulp: P < 0.001; PDL: P = 0.022), but there was no statistically significant difference in the detection rate of the number of root canals between the two (P > 0.05). Although the imaging scores for dental pulp and PDL as well as the detection rate of the number of root canals with 5T MRI were inferior to those with CBCT (dental pulp: P < 0.001; PDL: P = 0.02; number of root canals: P < 0.05), 5T MRI can truly achieve "direct imaging" of these two soft tissues. Conclusion 5T MRI enables effective in vivo direct imaging of dental pulp and PDL tissues in the young adult population, indicating its potential clinical application value in the diagnosis and treatment of pulp and periodontal diseases.

Objective: To understand the impact of childhood trauma on psychological distress among upper grade elemetary school students, and to explore the mediating role of leisure activities in the relationship, so as to provide a basis for developing mental health intervention strategies. Methods: From August to November 2024, a combination of convenience sampling and stratified cluster random sampling was employed to recruit 1 373 fourth to sixth grade students from four primary schools in Harbin. The Childhood Trauma Questionnaire(CTQ), a self designed leisure activity scale (including active and passive leisure activities), and the Kessler Psychological Distress Scale (K10) were used to assess childhood trauma experiences, leisure activities, and levels of psychological distress. Spearman correlation analysis and linear regression analysis were conducted to explore the relationships among childhood trauma, leisure types, leisure time, and psychological distress. Based on the mediation analysis framework proposed by Hayes (Model 4), the mediating role of leisure types in the relationship between childhood trauma and psychological distress was examined. Results: Totally 19.1% of the upper elemetary school students exhibited psychological distress, while 30.2% had experienced childhood trauma. During school days, 64.6% of the students were reported of having leisure time concentrated between 1 and 5 hours per day, whereas 67.4% reported leisure time exceeding 5 hours per day on weekends. After controlling for potential demographic confounders such as gender, grade, ethnicity, household registration, being an only child, parents educational level, co residence, and whether parents are first time married,linear regression analysis showed that childhood trauma experience had positive predictive effect on psychological distress in upper primary school students( β =0.20, P <0.01). Leisure time showed no statistically significant association with psychological distress, both on school days ( β =-0.58 to -0.56) and weekends ( β =0.26- 0.98 )(all P >0.05). Active leisure activities were negatively associated with psychological distress ( β =-0.20), while passive leisure activities were positively associated with psychological distress ( β =0.29)(both P <0.01). Leisure type partially mediated the relationship between childhood trauma and psychological distress, accounting for 11.7% of the indirect effect. Conclusion Childhood trauma experiences positively predict psychological distress in upper elementary school students, and affect psychological distress through active leisure and passive leisure.

BACKGROUND:Spinal canal decompression using uniportal endoscopic surgery is a new minimally invasive surgery in the treatment of lumbar spinal stenosis.However,this technique needs a steep learning curve and high requirements for surgical equipment and instruments,which limits its clinical application.We previously use the spinal endoscopy as a monitoring endoscopy and combined with unilateral biportal endoscopy to propose a hybrid technique of spinal endoscopy to achieve coaxial endoscopic operation and hands-separate operation. OBJECTIVE:To compare the clinical outcome of hybrid technique and uniportal endoscopic surgery in treatment of lumbar spinal stenosis with bilateral lower limb pain symptoms. METHODS:Ninety patients diagnosed of lumbar spinal stenosis with bilateral symptoms were included and retrospectively analyzed at First People's Hospital,Shanghai Jiao Tong University from August 2020 to August 2022.44 cases were included in group A(hybrid technique group),while 46 cases were included in group B(uniportal endoscopic surgery).The nerve decompression was observed during the surgery.Operation time,hospital stay time,and expenses were recorded in both groups.The visual analog scale scores of lower back pain and both lower extremities pain,Oswestry disability index scores of quality of life and excellent and good rate of modified Macnab criteria were recorded and compared at preoperative,postoperative 3 days,and postoperative 3 and 6 months. RESULTS AND CONCLUSION:(1)The operation time of group A was significantly shorter than that of group B(P<0.05).(2)The lower back pain and lower extremity pain of the severe side at postoperative 3 days,and 3 and 6 months were significantly relieved in both groups(P<0.05).The visual analog scale score of lower extremity pain on the mild side was significantly decreased at postoperative 3 days,3 and 6 months than preoperative score in the group A(P<0.05).The visual analog scale score of lower extremity pain on the mild side was significantly decreased at postoperative 3 days than preoperative score in the group B(P<0.05).The visual analog scale scores of lower extremity pain on the mild side at postoperative 3 and 6 months did not show significant difference than preoperative score in the group B.The comparison between the two groups showed that there was no significant difference in the visual analog scale scores of postoperative lower back pain and lower extremity pain of the severe side(P>0.05).The visual analog scale scores of lower extremity pain on the mild side in the group A were significantly lower than those of group B at postoperative 3 and 6 months(P<0.05).(3)The Oswestry disability index scores of both groups at postoperative 3 day were significantly lower than preoperative score(P<0.05),and there was no significant difference between the two groups 3 days after operation.Oswestry disability index scores of group A at postoperative 3 and 6 months were significantly decreased than preoperative score(P<0.05).The Oswestry disability index scores of group B at postoperative 3 and 6 months did not show significant differences than preoperative score(P>0.05).The comparison between the two groups showed the Oswestry disability index scores of group A were significantly lower than group B at postoperative 3 and 6 months(P<0.05).(4)The results of modified Macnab showed that the excellent and good rate of group A was significantly higher than that of group B(95%,78%,P<0.05).(5)It is indicated that the hybrid technique is a new spinal endoscopy technique,which has the advantages of less trauma and faster recovery as a minimally invasive surgery.The clinical outcome of hybrid technique is superior to that of uniportal endoscopic surgery in the treatment of lumbar spinal stenosis with bilateral symptoms.Additionally,it also has the advantages of good operational flexibility and high decompression efficiency as an open surgery.

Objective To analyze the clinical significance of subjective visual vertical (SVV) tests at different head deflection angles in assessing utricle function in patients with benign paroxysmal positional vertigo (BPPV). Methods A total of 61 BPPV patients who were treated at the Hearing Impairment and Vertigo Diagnosis and Treatment Center of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine from August 2022 to May 2023 were retrospectively included, and 29 healthy adults were selected as controls. SVV tests were performed on all research subjects at different head deflection angles: upright head (0°), left head 45° (L45°), right head 45° (R45°). The test results between the two groups were compared. Results SVV absolute value at R45° in BPPV group was lower than that in the control group (P＝0.003); there was no significant difference in SVV values at 0° and L45° between the two groups. There was no statistical difference in SVV values at different head deflection angles between the control group and the left BPPV group. SVV absolute value at R45° in right BPPV group was lower than that in the control group (P＜0.001); there was no statistical difference in SVV values at 0° and L45° between the two groups. Conclusions SVV test can provide subjective information about the utricle, and SVV tests at different head deflection angles can fine-tune evaluate the function of the utricle in BPPV patients.

ObjectiveTo establish a rat model of osteoarthritis and study the anti-inflammatory effects and mechanisms of fraxetin. MethodsEighteen 8-week-old male SPF-grade SD rats were randomly divided into three groups: Rats in the blank group received a right articular cavity injection of 50 μL of normal saline for 1 week; the model and intervention groups were injected with monosodium iodoacetate (MIA) into the right joint cavity to induce osteoarthritis, while the intervention group subsequently received fraxetin (5 mg·kg^-1·d^-1) for 1 week. Four weeks after drug intervention, abdominal aortic blood was collected. The animals were then euthanized, and knee joint cartilage were collected. The cartilage samples were stained with hematoxylin-eosin, safranin O-fast green, and toluidine blue for histopathological examination and scoring using the Mankin and OARSI scoring systems. The trabecular bone volume/total volume (Tb.BV/TV), trabecular bone surface density/total volume (Tb.BS/TV), and trabecular number (Tb.N) of each group were compared and analyzed using a micro-CT scanning system. The expression levels of various inflammatory factors [tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6)], and cartilage oligomeric matrix protein (COMP) were measured using enzyme-linked immunosorbent assay (ELISA). The expression levels of mitogen-activated protein kinase p38 (p38 MAPK), phosphorylation-p38 MAPK (p-p38 MAPK), c-Jun N-terminal kinase (JNK), and phosphorylation-JNK (p-JNK) were measured by western blotting. ResultsThe staining of cartilage sections of rat knee joints showed that the articular surface defects in the model group were severe, while the cartilage destruction in the intervention group was relatively reduced. Micro-CT results showed that Tb.BV/TV, Tb.BS/TV and Tb.N in the intervention group were significantly higher than those in the model group (P < 0.05); the Mankin score in the model group was significantly higher than that in the blank group (P < 0.05), the Mankin score in the intervention group was significantly lower than that in the model group (P < 0.05); while the OARSI score in the intervention group was significantly lower than that in the model group (P < 0.05). The results of the enzyme-linked immunosorbent assay showed that the serum levels of TNF-α, IL-1β, IL-6, and COMP in the model group were significantly higher than those in the blank group (all P < 0.05), while those in the intervention group were significantly lower than in the model group (P < 0.05). Western blot results showed that the expression levels of p-p38 MAPK and p-JNK in the knee cartilage tissue were significantly lower in the intervention group than in the model group (both P < 0.05), and significantly higher in the model group than in the blank group (both P < 0.05). ConclusionFraxetin may play a therapeutic role in a monosodium iodoacetate-induced rat model of osteoarthritis through the p38 MAPK pathway.

ObjectiveTo establish a rat model of osteoarthritis and study the anti-inflammatory effects and mechanisms of fraxetin. MethodsEighteen 8-week-old male SPF-grade SD rats were randomly divided into three groups: Rats in the blank group received a right articular cavity injection of 50 μL of normal saline for 1 week; the model and intervention groups were injected with monosodium iodoacetate (MIA) into the right joint cavity to induce osteoarthritis, while the intervention group subsequently received fraxetin (5 mg·kg^-1·d^-1) for 1 week. Four weeks after drug intervention, abdominal aortic blood was collected. The animals were then euthanized, and knee joint cartilage were collected. The cartilage samples were stained with hematoxylin-eosin, safranin O-fast green, and toluidine blue for histopathological examination and scoring using the Mankin and OARSI scoring systems. The trabecular bone volume/total volume (Tb.BV/TV), trabecular bone surface density/total volume (Tb.BS/TV), and trabecular number (Tb.N) of each group were compared and analyzed using a micro-CT scanning system. The expression levels of various inflammatory factors [tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6)], and cartilage oligomeric matrix protein (COMP) were measured using enzyme-linked immunosorbent assay (ELISA). The expression levels of mitogen-activated protein kinase p38 (p38 MAPK), phosphorylation-p38 MAPK (p-p38 MAPK), c-Jun N-terminal kinase (JNK), and phosphorylation-JNK (p-JNK) were measured by western blotting. ResultsThe staining of cartilage sections of rat knee joints showed that the articular surface defects in the model group were severe, while the cartilage destruction in the intervention group was relatively reduced. Micro-CT results showed that Tb.BV/TV, Tb.BS/TV and Tb.N in the intervention group were significantly higher than those in the model group (P < 0.05); the Mankin score in the model group was significantly higher than that in the blank group (P < 0.05), the Mankin score in the intervention group was significantly lower than that in the model group (P < 0.05); while the OARSI score in the intervention group was significantly lower than that in the model group (P < 0.05). The results of the enzyme-linked immunosorbent assay showed that the serum levels of TNF-α, IL-1β, IL-6, and COMP in the model group were significantly higher than those in the blank group (all P < 0.05), while those in the intervention group were significantly lower than in the model group (P < 0.05). Western blot results showed that the expression levels of p-p38 MAPK and p-JNK in the knee cartilage tissue were significantly lower in the intervention group than in the model group (both P < 0.05), and significantly higher in the model group than in the blank group (both P < 0.05). ConclusionFraxetin may play a therapeutic role in a monosodium iodoacetate-induced rat model of osteoarthritis through the p38 MAPK pathway.