Objective:To analyze the reoperation rate and causes during the early adoption phase of unilateral biportal endoscopy (UBE).Methods:The clinical data of 180 patients who underwent UBE performed by a single surgeon at Beijing Friendship Hospital, Capital Medical University from October 2021 to June 2023 were retrospectively analyzed. Clinical and imaging data of patients who underwent reoperation were collected to analyze the causes of reoperation, and the clinical efficacy of the reoperations was also followed up. Measurement data were expressed as mean ± standard deviation ( ± s), and t-test was used before and after treatment. Results:A total of 180 patients who underwent UBE were included in this study, of which 6 patients underwent reoperation, and the reoperation rate was 3.33%. Among them, 3 cases occurred in the first 90 surgeries and the other 3 occurred in the subsequent 90 surgeries. The causes of reoperation were as follows: recurrent lumbar disc herniation at the same segment postoperatively in 2 cases, insufficient decompression in 2 cases, disc herniation following isolated decompression in 1 case, and immediate postoperative perianal numbness in 1 case. The time between the initial surgery and reoperation ranged from 0 to 187 days, with an average of 63.3 days. The average follow-up time after reoperation was 18.3 months. The visual analogue scale (VAS) and Oswestry disability index (ODI) scores of the patients at the last follow-up were significantly improved compared with those before operation (VAS score of low back pain: 5.2 ± 1.7 before operation, 1.2 ± 0.8 at the last follow-up, P<0.001; VAS score of leg pain: 7.2 ± 1.5 before operation, 1.2 ± 1.2 at the last follow-up, P<0.001; ODI score: 67.3 ± 5.7 before operation, 20.2 ± 8.2 at the last follow-up, P<0.001). The postoperative modified MacNab scores were generally satisfactory (4 cases were rated as excellent, accounting for 66.7%; 2 cases were rated as good, accounting for 33.3%). Except for one patient who experienced dural injury during open revision surgery, there were no serious complications such as nerve damage. Conclusions:In the early stages of UBE surgery, recurrent lumbar disc herniation and inadequate decompression are the primary reasons for reoperation, typically occurring within the first three months postoperatively. Reoperation does not significantly increase the risk of nerve injury. Enhanced early postoperative follow-up is recommended. For symptomatic patients, a second surgery with thorough decompression can yield satisfactory treatment outcomes.

Objective:To analyze the learning curve of TiRobot-assisted lumbar pedicle screw fixation (LPSF) by cumulative sum (CUSUM) test method.Methods:The clinical data of 50 patients who underwent TiRobot-assisted LPSF from January 2020 to December 2022 in Beijing Friendship Hospital, Capital Medical University were retrospectively analyzed. CUSUM analysis and learning curve fitting were performed with robot usage time as the main indicator with the time for each step refined (robot registration time, path planning time and guide wire placement time), to select the best learning curve fitting model with the R2 value closest to 1. Using the turning point of the learning curve as the boundary, the learning curve was divided into two stages as learning stage and maturity stage, and then the observation indexes were compared between the two stages. Results:All 50 patients successfully completed the surgery without perioperative complications, with a total of 244 pedicle screws implanted. The total robot usage time and robot registration time showed a gradually decreasing trend with the increase of case number, and the learning curves were successfully fitted and reached their peaks at the seventeenth and thirteenth cases respectively. The entire learning process was divided into learning stage (17 cases) and maturity stage (33 cases) based on the turning point of the learning curve of total robot usage time. The path planning time and guide wire placement time did not show significant changes with the increase in the case number. The total robot usage time, robot registration time and the intraoperative blood loss in the learning stage were significantly higher than those in the maturity stage: (35.35 ± 1.58) min vs. (30.61 ± 0.43) min, (20.83 ± 1.56) min vs. (14.94 ± 0.29) min and 400 (150, 500) ml vs. 200 (110, 300) ml, the guide wire placement time of per screw was significantly lower than that in the maturity stage: 2.00 (1.83, 2.34) min/screw vs. 2.33 (2.13, 2.69) min/screw, and there were statistical differences ( P<0.05 or <0.01). There were no statistical difference in the path planning time, path planning time of per screw, guide wire placement time and the accuracy of screw placement between two stages ( P>0.05). Conclusions:TiRobot-assisted LPSF is a new technology with safety and effectiveness, and it has a relatively short learning curve. To achieve technological maturity, at least 17 surgeries are required with accumulated experience, and the robot registration is the main step of the learning process. After reaching maturity stage, the robot usage time is significantly shortened and intraoperative trauma is significantly reduced while the relatively high screw placement accuracy is ensured.

[Objectives]To investigate the effect of METTL3 on the malignant biological behaviors of uveal melanoma cells and to verify whether this effect is related to m6A methylation.[Methods]Uveal melanoma cell models with METTL3 knockdown,overexpression,and point mutations at m6A-related catalytic sites were constructed via lentivirus transfection.Transwell assays were used to assess cell migration and invasion;CCK8 assays were used to measure cell proliferation and flow cytometry was used to analyze apoptosis and cycle changes.[Results]The proliferation,migration and invasion abilities of C918 and MUM-2B cells with METTL3 knockdown were significantly decreased(P<0.001),while the apoptosis rate was increased.The proportion of cells in G1 phase significantly increased,whereas the proportion in the S phase significantly decreased.Cells overexpressing METTL3 showed significantly enhanced proliferation,migration and invasion abilities(P<0.001),along with a decreased apoptosis rate.In C918 cells,the proportion of cells in G1 phase decreased significantly,while the proportion in S phase increased significantly.The cell cycle distribution of MUM-2B cells did not change remarkably.Following point mutation of m6A-related catalytic sites,cell proliferation,migration and invasion decreased,and the apoptosis rate increased.In MUM-2B cells,the percentage of cells in G1 phase significantly increased;the percentage in S phase significantly decreased and the percentage in G2 phase slightly decreased.In C918 cells,the percentage of G1 phase cells significantly increased,with no significant changes in the proportions of S and G2 phases.[Conclusions]The proliferation,invasion and metastasis of uveal melanoma cells were positively correlated with the expression of METTL3,while the apoptosis rate was negatively correlated.Changes in METTL3 levels differentially affect the cell cycles in different cell lines.The effects of METTL3 on the proliferation,migration and invasion of uveal melanoma cells are related to m6A methylation modification.

Objective To evaluate the accuracy of 6 commercial antibiotic susceptibility testing methods in detecting the sensitivity of carbapenems-resistant Klebsiella pneumoniae(CRKP)to tigecycline,and to provide an evidence for clinical laboratory to select the appropriate tigecyline susceptibility tests.Methods Non-duplicate CRKP clinically isolated from Aerospace Center Hospital from June 2023 to February 2024 were collected.60 cases of tigecycline intermediated CRKP[minimal inhibitery concentration(MIC)=4μg/ml]and 60 cases of drug-resistant CRKP(MIC≥8μg/ml)were screened by Vitek-2.The sensitivity of CRKP to tigecycline was detected by different methods.With the MIC test strip(MTS)as the reference method,the methodological evaluation of Vitek-2,commercial broth dilution method,E-test,Kirby-Bauer disk diffusion(KB)and disk combined with resensitization bufferwas carried out under the interpretation standards of the U S Food and Drug Administration(FDA)and the European Commission for Drug Susceptibility Testing(EUCAST),respectively.Results For the intermediate strains,under the FDA criteria,both the commercial broth dilution method and the disk combinedwith resensitization buffer method showed high consistency with the MTS method and were acceptable,whereas under the EUCAST criteria,all five methods were unacceptable.For the resistant strains,no matter what standard was,CA of all five methods were less than 90%,which were unacceptable.For all strains as a whole,the results were consistent with those of the resistant ones.Conclusion Under the current sample size,none of the five methods met the acceptable standards,especially not suitable for the recheck of strains with higher MICs.Commercial broth dilution method have the highest consistency with MTS,and it is worth expanding the sample size for further study.

Objective To evaluate the accuracy of 6 commercial antibiotic susceptibility testing methods in detecting the sensitivity of carbapenems-resistant Klebsiella pneumoniae(CRKP)to tigecycline,and to provide an evidence for clinical laboratory to select the appropriate tigecyline susceptibility tests.Methods Non-duplicate CRKP clinically isolated from Aerospace Center Hospital from June 2023 to February 2024 were collected.60 cases of tigecycline intermediated CRKP[minimal inhibitery concentration(MIC)=4μg/ml]and 60 cases of drug-resistant CRKP(MIC≥8μg/ml)were screened by Vitek-2.The sensitivity of CRKP to tigecycline was detected by different methods.With the MIC test strip(MTS)as the reference method,the methodological evaluation of Vitek-2,commercial broth dilution method,E-test,Kirby-Bauer disk diffusion(KB)and disk combined with resensitization bufferwas carried out under the interpretation standards of the U S Food and Drug Administration(FDA)and the European Commission for Drug Susceptibility Testing(EUCAST),respectively.Results For the intermediate strains,under the FDA criteria,both the commercial broth dilution method and the disk combinedwith resensitization buffer method showed high consistency with the MTS method and were acceptable,whereas under the EUCAST criteria,all five methods were unacceptable.For the resistant strains,no matter what standard was,CA of all five methods were less than 90%,which were unacceptable.For all strains as a whole,the results were consistent with those of the resistant ones.Conclusion Under the current sample size,none of the five methods met the acceptable standards,especially not suitable for the recheck of strains with higher MICs.Commercial broth dilution method have the highest consistency with MTS,and it is worth expanding the sample size for further study.

Objective:To analyze the learning curve of TiRobot-assisted lumbar pedicle screw fixation (LPSF) by cumulative sum (CUSUM) test method.Methods:The clinical data of 50 patients who underwent TiRobot-assisted LPSF from January 2020 to December 2022 in Beijing Friendship Hospital, Capital Medical University were retrospectively analyzed. CUSUM analysis and learning curve fitting were performed with robot usage time as the main indicator with the time for each step refined (robot registration time, path planning time and guide wire placement time), to select the best learning curve fitting model with the R2 value closest to 1. Using the turning point of the learning curve as the boundary, the learning curve was divided into two stages as learning stage and maturity stage, and then the observation indexes were compared between the two stages. Results:All 50 patients successfully completed the surgery without perioperative complications, with a total of 244 pedicle screws implanted. The total robot usage time and robot registration time showed a gradually decreasing trend with the increase of case number, and the learning curves were successfully fitted and reached their peaks at the seventeenth and thirteenth cases respectively. The entire learning process was divided into learning stage (17 cases) and maturity stage (33 cases) based on the turning point of the learning curve of total robot usage time. The path planning time and guide wire placement time did not show significant changes with the increase in the case number. The total robot usage time, robot registration time and the intraoperative blood loss in the learning stage were significantly higher than those in the maturity stage: (35.35 ± 1.58) min vs. (30.61 ± 0.43) min, (20.83 ± 1.56) min vs. (14.94 ± 0.29) min and 400 (150, 500) ml vs. 200 (110, 300) ml, the guide wire placement time of per screw was significantly lower than that in the maturity stage: 2.00 (1.83, 2.34) min/screw vs. 2.33 (2.13, 2.69) min/screw, and there were statistical differences ( P<0.05 or <0.01). There were no statistical difference in the path planning time, path planning time of per screw, guide wire placement time and the accuracy of screw placement between two stages ( P>0.05). Conclusions:TiRobot-assisted LPSF is a new technology with safety and effectiveness, and it has a relatively short learning curve. To achieve technological maturity, at least 17 surgeries are required with accumulated experience, and the robot registration is the main step of the learning process. After reaching maturity stage, the robot usage time is significantly shortened and intraoperative trauma is significantly reduced while the relatively high screw placement accuracy is ensured.

[Objectives]To investigate the effect of METTL3 on the malignant biological behaviors of uveal melanoma cells and to verify whether this effect is related to m6A methylation.[Methods]Uveal melanoma cell models with METTL3 knockdown,overexpression,and point mutations at m6A-related catalytic sites were constructed via lentivirus transfection.Transwell assays were used to assess cell migration and invasion;CCK8 assays were used to measure cell proliferation and flow cytometry was used to analyze apoptosis and cycle changes.[Results]The proliferation,migration and invasion abilities of C918 and MUM-2B cells with METTL3 knockdown were significantly decreased(P<0.001),while the apoptosis rate was increased.The proportion of cells in G1 phase significantly increased,whereas the proportion in the S phase significantly decreased.Cells overexpressing METTL3 showed significantly enhanced proliferation,migration and invasion abilities(P<0.001),along with a decreased apoptosis rate.In C918 cells,the proportion of cells in G1 phase decreased significantly,while the proportion in S phase increased significantly.The cell cycle distribution of MUM-2B cells did not change remarkably.Following point mutation of m6A-related catalytic sites,cell proliferation,migration and invasion decreased,and the apoptosis rate increased.In MUM-2B cells,the percentage of cells in G1 phase significantly increased;the percentage in S phase significantly decreased and the percentage in G2 phase slightly decreased.In C918 cells,the percentage of G1 phase cells significantly increased,with no significant changes in the proportions of S and G2 phases.[Conclusions]The proliferation,invasion and metastasis of uveal melanoma cells were positively correlated with the expression of METTL3,while the apoptosis rate was negatively correlated.Changes in METTL3 levels differentially affect the cell cycles in different cell lines.The effects of METTL3 on the proliferation,migration and invasion of uveal melanoma cells are related to m6A methylation modification.

BACKGROUND: Syringomyelia is a progressive chronic disease that leads to nerve pain, sensory dissociation, and dyskinesia. Symptoms often do not improve after surgery. Stem cells have been widely explored for the treatment of nervous system diseases due to their immunoregulatory and neural replacement abilities. METHODS: In this study, we used a rat model of syringomyelia characterized by focal dilatation of the central canal to explore an effective transplantation scheme and evaluate the effect of mesenchymal stem cells and induced neural stem cells for the treatment of syringomyelia. RESULTS: The results showed that cell transplantation could not only promote syrinx shrinkage but also stimulate the proliferation of ependymal cells, and the effect of this result was related to the transplantation location. These reactions appeared only when the cells were transplanted into the cavity. Additionally, we discovered that cell transplantation transformed activated microglia into the M2 phenotype. IGF1-expressing M2 microglia may play a significant role in the repair of nerve pain. CONCLUSION Cell transplantation can promote cavity shrinkage and regulate the local inflammatory environment.Moreover, the proliferation of ependymal cells may indicate the activation of endogenous stem cells, which is important for the regeneration and repair of spinal cord injury.

Background: Using commutable external quality assessment (EQA) materials is important for monitoring successful harmonization efforts. We assessed the commutability of four human serum pool (HSP) preparations to identify candidate EQA materials for alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity measurement. Methods: One set each of 85 clinical samples (CSs) was collected for ALT and AST activity measurement. The 15 candidate EQA materials included four types of HSP preparations (A to D): materials A, C, and D contained human original recombinant (HOR) aminotransferases; materials B was mixed leftover samples. The CSs and 15 candidate EQA materials were analyzed using seven routine assays, and the ln-transformed results were analyzed in 21 assay pairs. Commutability was assessed using Deming regression, with a 95% prediction interval (CLSI approach) and the difference in bias with an error component model (International Federation of Clinical Chemistry and Laboratory Medicine [IFCC] approach). Results: For ALT, all materials were commutable for 14–21 assay pairs according to the CLSI and IFCC approaches. For AST, B01-03 showed commutability for 14-21 assay pairs, and C01-03 and D01-03 showed commutability for no less than 10 assay pairs according to the two approaches. A01-06 were commutable for 9-16 assay pairs according to the CLSI approach, but for 6-9 assay pairs according to the IFCC approach. Conclusions Mixed leftover samples showed desirable commutability characteristics as candidate EQA materials for routine aminotransferase activity measurements. Human serum bases supplemented with HOR were commutable for most routine ALT activity measurements.

[Abstract] Objective: To investigate the effects of miR-223-3p on the proliferation and apoptosis of hepatocellular carcinoma (HCC) cells by regulating Ras-related C3 botulinum toxin substrate 1 (RAC1) and its possible mechanism. Methods: Thirty pairs of HCC and corresponding para-cancer tissues resected in Jilin Central Hospital from August 2016 to August 2018 were collected for this study; in addition, human HCC cell lines SMMC-7721, BEL-7402, HepG2 and human normal hepatocyte QSG-7701 were also collected. The expression level of miR-223-3p in HCC tissue and cell lines was detected by qPCR. miR-223-3p mimics, miR-223-3p inhibitor and siRAC1 were transfected into SMMC-7221 cells, respectively. CCK-8 assay, Colony formation assay and Annexin V-FITC/PI staining Flow cytometry were used to detect the proliferation, clone formation and apoptosis of SMMC-7721 cells, respectively. The relationship between miR-223-3p and RAC1 was confirmed by Dual luciferase reporter gene assay. The protein level of RAC1 in SMMC-7721 cells was detected by Western blotting. Results: The expression of miR-223-3p in HCC tissues was significantly lower than that in paracaner tissues (P<0.01), and had significant correlation with pathological characteristics, such as tumor size, TNM stage, EdmondsonSteiner grade (all P<0.05 or P<0.01). miR-223-3p expression in HCC cell lines was significantly lower than that in QSG-7701 cells with the lowest expression in SMMC-7721 cells. Dual luciferase reporter gene assay confirmed that RAC1 was a target gene of miR-223-3p, and miR-223-3p negatively regulated RAC1 expression. Over-expression of miR-223-3p significantly inhibited the proliferation and colony formation (P<0.05 or P<0.01) of SMMC-7721 cells and promoted cell apoptosis (P<0.01). Contrarily, knockdown of miR-223-3p reversed the inhibitory effect of miR-223-3p mimics on cells. Conclusion: miR-223-3p over-expression inhibits proliferation and colony formation and promotes apoptosis of HCC cells, the mechanism of which may be related with its targeted down-regulation of RAC1.