BACKGROUND: Stem cells from the apical papilla (SCAP) play important roles in the formation and development of dental roots. However, the immune-modulating capacity of SCAP has not been fully elucidated. OBJECTIVE: To test the therapeutic effects of transplantation of SCAP on dextran sulfate sodium-induced experimental colitis. METHODS: Twenty-four C57/BL6 mice were equally divided into four groups (normal control, positive control, SCAP treatment group, and FasL-knockdown SCAP group), and latter three groups of mice were induced to acute experimental colitis by 3% dextran sulfate sodium in drinking water. At day 3 after modeling, model mice were treated with PBS, human SCAP (2×106 cells), and FasL-knockdown SCAP via intraperitoneal injection, respectively. Inflammation was evaluated by measuring body mass and length of the colon, detecting levels of interleukin 1β, interleukin 6 and tumor necrosis factor α, as well as histological analyses at day 10 after modeling. Levels of Tregs in mesenteric lymph nodes in mice were detected using flow cytometric analysis. RESULTS AND CONCLUSION: SCAP transplantation could ameliorate the inflammation in dextran sulfate sodium-induced colitis mice, and body mass loss and symptoms were significantly improved. Pathological score and the levels of three inflammatory cytokines in the colon tissue decreased significantly. Flow cytometric analysis revealed an increased level of Tregs in mesenteric lymph nodes. Knocking down of FasL gene in SCAP abrogated the therapeutic effects of SCAP in ameliorating dextran sulphate sodium-induced colitis. Therefore, Fas-FasL pathway played an important role in the underlying mechanism of the immune-modulating capacity of SCAP.

BACKGROUND: Studies have shown that platelet-rich plasma has a strong role in promoting chondrocyte repair and proliferation. OBJECTIVE: To investigate the efficacy of platelet-rich plasma in chondrocyte repair and synovial inflammation inhibition in osteoarthritis. METHODS: The blood samples were extracted from the central artery of the ear in 40 New Zealand white rabbits and platelet-rich plasma was prepared by the method of Hokugo. The platelet, platelet-derived growth factor, transforming growth factor-3, vascular endothelial growth factor in the peripheral blood and platelet-rich plasma were detected simultaneously. Animal models were made by resection of anterior cruciate ligament and divided into experimental group and control group. In the experimental group, 0.3 mL of platelet-rich plasma was injected once a week for 10 weeks; in the control group, 0.3 mL of sterile saline was injected once a week for 10 weeks. Gross observation and histological observation of knee joints were performed; articular cartilage type II collagen and matrix metalloproteinase 13 levels were measured; and Mankin score of the cartilage tissue was performed at 2, 4, 6, 8, and 10 weeks after injection. The study protocol was approved by the Animal Experiment Ethics Committee of Chongqing Medical University. RESULTS AND CONCLUSION: (1) The concentrations of platelet, platelet-derived growth factor, transforming growth factor-3, vascular endothelial growth factor in platelet-rich plasma were 5.5, 4.8, 7.7, and 6.2 times those of the peripheral blood, respectively. And there were significant differences between the platelet-rich plasma and peripheral blood (P<0.05). (2) From the 6th week, the Mankin score of the experimental group was significantly lower than that of the control group (P<0.05). (3) The expression of type II collagen protein in the experimental group was significantly higher than that in the control group at the 4th, 6th, 8th and 10th weeks after injection (P<0.05). The expression of matrix metalloproteinase-13 was significantly lower than that in the control group at the 2nd, 4th, 6th, 8th and 10th week (P<0.05). All these findings indicate that intra-articular injection of platelet-rich plasma can inhibit the development of osteoarthritis by alleviating synovial inflammation and delaying or blocking the damage of chondrocytes.

OBJECTIVE: To construct recombinant adenovirus expressing nerve growth factor (NGF) and myelin associated glycoprotein (MAG) (Ad-NGF-MAG) and to investigate its effect on repair and regeneration of sciatic nerve injury in rats.

Objective: To observe effectivness and safeness of self-made dentation hook plate associated with hot-air balloon technique in treating Mutch Ⅰ or Ⅱ type isolated greater tuberosity fractures of humerus. Methods: Between January 2016 and December 2018, 15 patients with Mutch Ⅰ or Ⅱ type greater tuberosity fractures were treated with self-made dentation hook plate associated with hot-air balloon technique. There were 9 males and 6 females with an average age of 45.1 years (range, 29-62 years). The injury causes included falling injury in 9 patients and traffic accident injury in 6 patients. According to Mutch classification, 4 cases were MutchⅠ type and 11 cases were Mutch Ⅱ type. There were 7 cases with anterior dislocation of shoulder. The time from injury to operation was 2-10 days (mean, 4.5 days). Results: All 15 patients were followed up 8-16 months, with an average of 13.5 months. There was no infection of incision, loss of reduction of fracture block, delayed union or nonunion. The average time of fracture union was 6.5 months (range, 4-8 months). One patient had axillary paralysis at 1 day after operation, and was treated with nutritional nerve therapy, the symptoms disappeared after 2.5 months. Three patients had slight subacromial impingement. After fracture healing, the hook plate was taken out in advance, and the pain and abnormal noise disappeared during shoulder abduction. At last follow-up, Costant-Murley score used to evaluate shoulder joint function was 88-100, with an average of 96.8; 8 cases were excellent, 7 cases were good, and the excellent and good rate was 100%. The internal fixator was removed after 8-16 months after the secondary operation with no re-fracture occurred. Conclusion: The self-made dentation hook plate associated with hot-air balloon technique is a safe and reliable method for the treatment of Mutch Ⅰ or Ⅱ type isolated greater tuberosity fracture of humerus.

To analyze the articles published in Journal of Medical Biomechanics during the year 2015-2019, so as to make references for improving the quality of the journal. Methods Based on data published by Chinese S&T Journal Citation Reports, the citation index and source index of the journal during the year 2015-2019 were collected for statistic analysis. Results During the year 2015-2019, the journal’s total citations, impact factors, number of citing journals, number of source papers, average citations were steadily increased. Eighty-four percent of the published papers were funded, with a wide range of subject distributions. Conclusions The 5-year academic impact of the journal has been improving. To expand the academic impact, the journal should make further efforts in giving full play to the role of the Editorial Committee, shortening the publication cycle, as well as strengthening propaganda and promotion of the journal.

ObjectiveTo explore the clinical efficacy of percutaneous transforaminal endoscopic spine system （TESSYS） in the treatment of lumbar disc herniation （LDH） complicated with nerve root canal stenosis. MethodsA retrospective study was done on 40 LDH patients complicated with nerve root canal stenosis who underwent TESSYS in our hospital from April 2019 to April 2021. The clinical efficacy of the patients was evaluated by the modified Mac Nab criteria 12 months after the surgery. We also measured and analyzed the scores of visual analogue scale （VAS）， Oswestry disability index （ODI） and Japanese orthopaedic association （JOA）， the changes of structural parameters of lumbar spine and inflammatory factor levels preoperatively， 6 and 12 months after the surgery. ResultsAll the 40 cases successfully underwent the surgery and follow-ups， with a 12-month post-operative clinical excellent and good rate of 90%. The preoperative， 6-month and 12-month post-operative VAS scores were （7.38±2.06）， （2.36±0.87） and （1.62±0.82）， respectively. The respective ODI scores were （55.54±11.19）， （26.52±7.61） and （18.14±4.36）； JOA scores （13.93±2.10）， （20.26±1.35） and （22.34±1.88）. The post-operative scores of VAS， ODI and JOA were significantly improved compared with those before the surgery （P<0.05）. The preoperative and post-operative lumbosacral angles were （37.23±6.84）° and （27.37±4.31）°， respectively， with the respective lumbar curvatures of （13.48±3.06） mm and （22.36±4.51） mm. The post-operative lumbosacral angle and lumbar curvature were significantly improved compared with those before the surgery （P<0.05）. The preoperative and post-operative high-sensitivity C-reactive protein （hs-CRP） levels were （3.43±0.61） mg/L and （5.18±0.70） mg/L， respectively， with the respective tumor necrosis factor alpha （TNF-α） levels of （1.44±0.27） mg/L and （2.07±0.44） mg/L. The post-operative levels of hs-CRP and TNF-α were significantly higher than those before the surgery （P<0.05）. ConclusionIn the treatment of LDH complicated with nerve root canal stenosis， TESSYS achieves a good clinical effect， improves the structure and function of the lumbar spine， reduces the degree of lumbar spine pain， and has a mild post-operative inflammatory reaction.

Objective　To analyze the correlation between N-terminal pro-brain natriuretic peptide （NT-proBNP） and causes of acute cerebral infarction （ACI），severity of neurological deficits，prognosis，so as to provide reference for clinical intervention of ACI. Methods　Eighty patients with ACI who were admitted to the hospital from January 2017 to April 2019 were selected as ACI group. Forty healthy volunteers who underwent physical examination in the hospital during the same period were enrolled as control group. Blood samples were collected from two groups （within 24 h～48 h after onset in patients with ACI） to detect the NT-proBNP level. The etiological types in the trial of Org10172 in acute stroke treatment （TOAST） were recorded. National Institutes of Health Stroke Scale （NIHSS） was applied to evaluate severity of neurological deficits at admission. The modified Rinkin Scale （MRS） was applied to evaluate prognosis after 3 months of admission. Blood NT-proBNP levels in patients with different general data and cardiac indicators were compared. The multiple linear regression analysis was applied to analyze correlation between serum NT-proBNP level and TOAST etiological type，severity of neurological deficits，prognosis in ACI patients. Results　①The serum NT-proBNP in ACI patients was significantly higher than that in control group （P<0.001）. ②The serum NT-proBNP in ACI patients with type cardiac embolism （CE） as TOAST etiology typing，NIHSS score not lower than 7 points，mRS not lower than 3 points，with atrial fibrillation and thickened interventricular septum thickness （IST） were significantly higher than that in patients with non-CE type，NIHSS score within 0-6 points，mRS lower than 3 points，without atrial fibrillation and with normal IST （P<0.05）. ③The multiple linear regression analysis showed that type CE as TOAST etiology typing，severity of neurological deficits （NIHSS score） and mRS after 3 months of admission were closely related to serum NT-proBNP （P<0.05）. And Pearson correlation coefficients （r） were 0.822，0.545 and 0.452，respectively. Conclusion　After 24 h～48 h of onset in ACI patients，there is good correlation between serum NT-proBNP and etiology typing of TOAST，severity of neurological deficits，prognosis，which deserves clinical attention.

Objective　To study the effects of repeated high-frequency cranial magnetic resonance on the fine motor function and cognitive function of upper limbs in patients with traumatic cerebral hemorrhage.Methods　Ninety-four patients with traumatic cerebral hemorrhage who were treated in our department of neurosurgery from September 2015 to June 2019 were enrolled as subjects.According to the random number method,44 patients with low-frequency cranial magnetic stimulation in the affected side were used as the control group,and 50 patients with high-frequency cranial magnetic stimulation in the affected side were used as the observation group.The Fugl-Meyer Assessment score (FMA),the modified Barthel index (MBI),the motor assessment scale (MAS),and the NIH Stroke Scale (NIHSS) were used to measure the daily life ability,fine motor function,and cognitive function in patients,the clinical treatment effects were compared between groups.Results　The clinical efficacy of traumatic cerebral hemorrhage in the observation group was significantly higher than that in the control group (P<0.05).FMA scores in the observation group were significantly higher than those in the control group both 2 weeks and 4 weeks after treatment (P<0.05).The MBI scores of the observation group were significantly higher than those of the control group 2 weeks and 4 weeks after treatment (P<0.05).The MAS scores in the observation group were significantly higher than those in the control group 2 weeks and 4 weeks after treatment (P<0.05).The NIHSS scores of the observation group were significantly lower than those of the control group (P<0.05).Conclusion　Repeated high-frequency magnetic stimulation can effectively improve the upper limb motor function,daily living ability and fine motor ability in patients with traumatic cerebral hemorrhage,and can effectively improve their cognitive function.

Objective　To investigate the relationships between serum microRNA-210 (mir-210),hypoxia inducible factor-1α (HIF-1α) and delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH).Methods　Two hundred and sixty patients with aSAH who were diagnosed and treated in the Department of Neurosurgery of our hospital were selected as the study objects.According to the occurrence of DCI after aSAH,they were divided into non DCI group (181 patients) and DCI group (79 patients).The clinical data of the two groups were collected,the levels of serum mir-210 were determined by real-time fluorescent quantitative PCR (qRT-PCR),and the levels of HIF-1α in serum were determined by enzyme-linked immunosorbent assay (ELISA).Results　There were significant differences in aneurysm location,Hunt-Hess grade and Fisher grade between the two groups (P<0.05).The levels of mir-210 and HIF-1α in DCI group were significantly higher than those in non DCI group (P<0.05).Pearson test showed that there was a positive correlation between serum mir-210 level and HIF-1α level in aSAH patients (P<0.05).Multivariate logistic regression analysis showed that Hunt-Hess grade≥3,Fisher grade≥3 and high levels of serum mir-210 and HIF-1α were independent risk factors for DCI after aSAH (P<0.05).ROC curve analysis showed that the area under the curve of DCI after aSAH predicted by serum mir-210 combined with HIF-1α level was higher than that predicted by the two alone,with the sensitivity of 83.33% and the specificity of 94.44%.Conclusions　The levels of mir-210 and HIF-1α in patients with DCI after aSAH are all increased,which can be used as potential indexes to judge the occurrence of DCI after aSAH.

Objective To evaluate the feasibility of dual-source low-dose computed tomography (CT) of the paranasal sinus in children, with acquisition at an ultra-low tube voltage (70 kVp) combined with the Flash scan. Methods CT scans of the paranasal sinus were performed on 80 pediatric patients who were divided into two groups according to different protocols (70 kVp protocol with Flash scan mode and the iterative reconstruction, pitch 3, the experimental group (group A), n = 40; 80 kVp protocol with conventional spiral mode, pitch 1.5, control group (group B), n = 40). For each examination, the CT dose index (CTDIvol), dose-length product (DLP) and effective dose (ED) were estimated. The image noise, signal-to-noise ratio (SNR) and overall subjective diagnostic image quality were also evaluated. Results The images of these two groups were all satisfied for the clinical diagnosis. For radiation dose, the CTDIvol (mGy), DLP (mGycm) and ED (mSv) values of the 70 kVp protocol were significantly lower than those of the 80 kVp protocol [CTDIvol: 0.39 ± 0.004 vs1.57 ± 0.009 mGy, P < 0.001; DLP: 6.31 ± 0.52 vs 19.88 ± 2.01 mGycm, P < 0.001; ED: 0.024 ± 0.005 vs 0.079 ± 0.016 mSv, P < 0.001. Compared with those of the 80-kVp protocol, the image noise and the SNR_bone increased, the SNR_soft-tissue decreased. There was no statistical difference in the subjective scores of the two groups of image quality by the two physicians (P > 0.05). Conclusion When diagnosing the paranasal sinus in children, an ultralow tube voltage (70 kVp) combined with the Flash scan technique can reduce the radiation dose significantly while maintaining diagnostic image quality with clinically acceptable image noise.