In order to establish a method for the detection of serum antibodies to donkey-derived e-quine coronavirus(ECoV),recombinant ECoV N protein was expressed in E.coli system,purified by nickel column affinity chromatography and identified by Western blot.After optimizing the re-action conditions,the indirect ELISA(iELISA)detection method was established using the puri-fied recombinant protein as coating antigen and used to detect 143 clinical serum samples.The re-sults showed that the recombinant N protein,which has good reaction activity with serum antibod-y,was successfully expressed.The optimum conditions of the established iELISA method were as follows:the amount of antigen coated was 0.2 μg/well and overnight at 4 ℃,10％skimmed milk powder solution was sealed at 37℃ for 1.5 h,the dilution concentration of serum was 1∶200,and the enzyme-labeled secondary antibody diluted at 1∶10 000.The sensitivity test results showed that the positive serum could be diluted to 1∶6 400.The specificity test results showed that all an-tibodies to several donkey pathogens were negative.The repetitive test results showed that the in-tra-and inter-batch coefficients of variation were 2.90％-6.12％and 2.29％-7.88％respectively.The positive rate of clinical donkey serum was 57.3％.The iELISA established in this study pro-vides a technical support for epidemiological investigation and antibody surveillance.

Objective:To investigate the efficacy and safety of a self-controlled chain ring combined with tissue clip traction-assisted technique for endoscopic submucosal dissection (ESD) of early colorectal tumors.Methods:Data of patients with early colorectal tumors in technically challenging locations who underwent ESD at the Digestive Endoscopy Center of Jiangsu Province Hospital of Chinese Medicine from January 2021 to April 2024 were enrolled in the retrospective cohort study. According to the treatment methods, they were divided into the traction-assisted ESD group (a self-controlled chain ring combined with tissue clip traction-assisted) and the traditional ESD group (without traction). Clinical endoscopic data, treatment conditions, and complications were compared between the two groups.Results:A total of 61 patients were enrolled, including 29 patients in the traction-assisted ESD group and 32 patients in the traditional ESD group. There were no significant differences in age, gender, tumor size, shape, location, pit pattern, pathological type, depth of invasion, one-time complete resection, or curative resection between the two groups ( P>0.05). The traction-assisted group demonstrated significantly shorter dissection times (37.55±20.44 min VS 60.78±29.34 min, t=-3.552, P<0.001) and lower complication rates [3.4% (1/29) VS 25.0% (8/32), χ2=4.035, P=0.045]. Complications in the traction-assisted ESD group included 1 muscularis propria superficial injury (no perforation/uncontrollable bleeding), versus 6 muscularis injuries and 2 micro-perforations in controls. Conclusion:The combined traction technique improves dissection efficiency and reduces procedural risks for challenging colorectal ESD.

Objective:To investigate the effect of bone morphogenetic protein-9(BMP9)overexpression on inflammatory response and apoptosis of alveolar epithelial cells induced by lipopolysaccharide(LPS).Methods:A549 cells were stimulated with 0.1 μg/ml LPS,expressions and changes of BMP9 protein at different time points(LPS stimulation for 0 h,6 h,12 h,24 h)were detected by Western blot.Expression of BMP9 in A549 cells was up-regulated by transfection of BMP9 plasmid,and the transfection efficiency was verified by Western blot and qPCR.After 12 h of LPS stimulation,levels of inflammatory factors TNF-α,IL-6,IL-1β in cell supernatant were detected by ELISA,expressions of anti-apoptotic protein(Bcl-2)and pro-apoptotic protein(Bax)were detected by Western blot,and apoptosis of cells was detected by TUNEL staining.Results:With the extension of LPS stimulation time,expression of BMP9 was down-regulated.Overexpression of BMP9 successfully up-regulated expression of BMP9 in A549 cells.LPS stimulation promoted secretions of TNF-α,IL-6 and IL-1β from A549 cells,increased apoptosis,promoted Bcl-2 expression while inhibited Bax expression.Overexpression of BMP9 inhibited TNF-α,IL-6 and IL-1β releasing,decreased apoptosis,inhibited Bcl-2 expression,while promoted Bax expression.Conclusion:In LPS-stimulated A549 cells,BMP9 expression is gradually decreased at a time-depen-dent manner.Overexpression of BMP9 can inhibit LPS-induced inflammatory response and apoptosis in A549 cells.

In order to establish a method for the detection of serum antibodies to donkey-derived e-quine coronavirus(ECoV),recombinant ECoV N protein was expressed in E.coli system,purified by nickel column affinity chromatography and identified by Western blot.After optimizing the re-action conditions,the indirect ELISA(iELISA)detection method was established using the puri-fied recombinant protein as coating antigen and used to detect 143 clinical serum samples.The re-sults showed that the recombinant N protein,which has good reaction activity with serum antibod-y,was successfully expressed.The optimum conditions of the established iELISA method were as follows:the amount of antigen coated was 0.2 μg/well and overnight at 4 ℃,10％skimmed milk powder solution was sealed at 37℃ for 1.5 h,the dilution concentration of serum was 1∶200,and the enzyme-labeled secondary antibody diluted at 1∶10 000.The sensitivity test results showed that the positive serum could be diluted to 1∶6 400.The specificity test results showed that all an-tibodies to several donkey pathogens were negative.The repetitive test results showed that the in-tra-and inter-batch coefficients of variation were 2.90％-6.12％and 2.29％-7.88％respectively.The positive rate of clinical donkey serum was 57.3％.The iELISA established in this study pro-vides a technical support for epidemiological investigation and antibody surveillance.

Objective:To investigate the effect of bone morphogenetic protein-9(BMP9)overexpression on inflammatory response and apoptosis of alveolar epithelial cells induced by lipopolysaccharide(LPS).Methods:A549 cells were stimulated with 0.1 μg/ml LPS,expressions and changes of BMP9 protein at different time points(LPS stimulation for 0 h,6 h,12 h,24 h)were detected by Western blot.Expression of BMP9 in A549 cells was up-regulated by transfection of BMP9 plasmid,and the transfection efficiency was verified by Western blot and qPCR.After 12 h of LPS stimulation,levels of inflammatory factors TNF-α,IL-6,IL-1β in cell supernatant were detected by ELISA,expressions of anti-apoptotic protein(Bcl-2)and pro-apoptotic protein(Bax)were detected by Western blot,and apoptosis of cells was detected by TUNEL staining.Results:With the extension of LPS stimulation time,expression of BMP9 was down-regulated.Overexpression of BMP9 successfully up-regulated expression of BMP9 in A549 cells.LPS stimulation promoted secretions of TNF-α,IL-6 and IL-1β from A549 cells,increased apoptosis,promoted Bcl-2 expression while inhibited Bax expression.Overexpression of BMP9 inhibited TNF-α,IL-6 and IL-1β releasing,decreased apoptosis,inhibited Bcl-2 expression,while promoted Bax expression.Conclusion:In LPS-stimulated A549 cells,BMP9 expression is gradually decreased at a time-depen-dent manner.Overexpression of BMP9 can inhibit LPS-induced inflammatory response and apoptosis in A549 cells.

Objective:To investigate the efficacy and safety of a self-controlled chain ring combined with tissue clip traction-assisted technique for endoscopic submucosal dissection (ESD) of early colorectal tumors.Methods:Data of patients with early colorectal tumors in technically challenging locations who underwent ESD at the Digestive Endoscopy Center of Jiangsu Province Hospital of Chinese Medicine from January 2021 to April 2024 were enrolled in the retrospective cohort study. According to the treatment methods, they were divided into the traction-assisted ESD group (a self-controlled chain ring combined with tissue clip traction-assisted) and the traditional ESD group (without traction). Clinical endoscopic data, treatment conditions, and complications were compared between the two groups.Results:A total of 61 patients were enrolled, including 29 patients in the traction-assisted ESD group and 32 patients in the traditional ESD group. There were no significant differences in age, gender, tumor size, shape, location, pit pattern, pathological type, depth of invasion, one-time complete resection, or curative resection between the two groups ( P>0.05). The traction-assisted group demonstrated significantly shorter dissection times (37.55±20.44 min VS 60.78±29.34 min, t=-3.552, P<0.001) and lower complication rates [3.4% (1/29) VS 25.0% (8/32), χ2=4.035, P=0.045]. Complications in the traction-assisted ESD group included 1 muscularis propria superficial injury (no perforation/uncontrollable bleeding), versus 6 muscularis injuries and 2 micro-perforations in controls. Conclusion:The combined traction technique improves dissection efficiency and reduces procedural risks for challenging colorectal ESD.

BACKGROUND:The repair of large-scale bone defects is still facing serious challenges.It is of great significance to develop personalized,low-cost,and osteogenic-inducing tissue engineering scaffolds for bone repair. OBJECTIVE:To explore the process of 3D printing bone tissue engineering scaffold containing pearl composite material by low-temperature condensation deposition method,and further test the physicochemical properties and in vitro biological functions of the composite scaffold. METHODS:Pearl powder was prepared by grinding and sieving.The pearl powder of different qualities was added into the poly-L-lactic acid ink,so that the mass ratio of pearl powder to poly-L-lactic acid was 0,0.1,0.2,0.3,and 0.5,respectively.The 3D-printed poly-L-lactic acid/pearl powder scaffolds were prepared using the low-temperature condensation deposition method.The microstructure,compressive properties,water contact angle,cytocompatibility,and in vitro bone differentiation ability of the printed poly-L-lactic acid/pearl powder composite scaffolds were detected. RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that the five groups of scaffolds all had micropores with a diameter of 2 μm or even smaller,irregular shapes and interconnectivity.(2)All the five groups had good compressive properties.The compressive strength of the pearl powder 0.5 group was higher than that of the other four groups(P<0.05).The water contact angle of the pearl powder 0.2 group and the pearl powder 0.5 group was smaller than that of the pearl powder 0 group(P<0.01,P<0.001).(3)Bone marrow mesenchymal stem cells were co-cultured with five groups of scaffolds for 1,3,and 5 days,respectively.The cell proliferation in pearl powder 0.1,0.2,0.3,and 0.5 groups cultured for 3 and 5 days was faster than that in pearl powder 0 group(P<0.05).After 1 day of culture,live-dead staining exhibited that the number of cells on the scaffold was small,but all of them were living cells.(4)Bone marrow mesenchymal stem cells were inoculated on the scaffold surface of the pearl powder 0 group and pearl powder 0.1 group respectively for osteogenic differentiation.The alkaline phosphatase activity induced for 4 and 6 days in the pearl powder 0.1 group was higher than that in the pearl powder 0 group(P<0.05).(5)The results showed that the poly-L-lactic acid/pearl powder composite scaffold had good compressive strength,hydrophilicity,cytocompatibility,and osteogenic properties.

Objective:To explore the effect of behavioral habits on the recovery of spinal cord function in patients with cervical spondylotic myelopathy after expansive open-door laminoplasty(ELAP).Methods:Retrospective analysis of clinical data of 183 patients with cervical spondylotic myelopathy who underwent ELAP at the Spinal Surgery Department of Jining Medical University Affiliated Hospital, from February 2019 to October 2022, with complete follow-up information. General clinical data of patients were collected. The patients were followed up at 3 months, 6 months and 12 months after surgery with the modified standard MacNab.The JOA score was used to evaluate the recovery of motor and sensory functions in patients before and 12 months after surgery. The recovery rate of spinal cord function was calculated based on the JOA score, and patients were divided into two groups: the group with good therapeutic effect ( n=143, recovery rate ≥ 50%) and the group with poor therapeutic effect ( n=40, recovery rate<50%). Data statistics were conducted using SPSS 20.0 software for chi-square test, rank sum test, t-test, and Logistic regression analysis. Results:There were significant differences in age ( t=-3.252, P<0.01), smoking ( χ2=21.503, P<0.01), body mass index(BMI) ( t=-5.885, P<0.01), hypertension ( χ2=20.263, P<0.01), coronary heart disease ( χ2=13.272, P<0.01), hospitalization time ( t=-2.278, P=0.02), desk and screen time ( t=-6.589, P<0.01), and frequency of rehabilitation exercise ( χ2=10.927, P<0.01) between the group with good therapeutic effect and the group with poor therapeutic effect. Further multivariate Logistic regression analysis showed that smoking ( B=2.402, OR=11.046, 95% CI=2.334-52.285, P<0.05), high BMI ( B=0.341, OR=1.406, 95% CI=1.076-1.837, P<0.05), hypertension ( B=2.238, OR=9.370, 95% CI=2.153-40.790, P<0.05), long desk and screen time ( B=0.961, OR=2.613, 95% CI=1.540-4.435, P<0.05) and low frequency of rehabilitation exercise ( B=-1.039, OR=0.354, 95% CI=0.201-0.623, P<0.05) were risk factors for spinal cord function recovery in patients with cervical spondylotic myelopathy after ELAP( P<0.05). Conclusion:Smoking, high BMI, hypertension, long desk and screen time, and low frequency of rehabilitation exercise are not adverse to the recovery of neurological function in patients with cervical spondylotic myelopathy after ELAP.

Objective:A new type of bio-ink and polycaprolactone (PCL) were used to construct an integrated osteochon-dral composite tissue block by multi-nozzle 3D bioprinter. And the repair results to osteochondral defects were evaluated.Methods:In freeze-drying group: Freeze-dried composite scaffold made by silk fibroin (SF) and β-tricalcium phosphate was used to repair osteochondral defects, as control. In the 3D printing group: PCL was used to printed a hollow multi-layer cylinder frame by 3D biological printer. Extracellular matrix, SF and bone marrow mesenchymal stem cells were used as chondral bio-ink. Then, chon-dral bio-ink was used to print tissue-engineered cartilage on top of PCL frame. Before implantation of cartilage defect, autogenous cancellous bone was filled in PCL frame, then the tissue-engineered osteochondral composite was used to repair osteochondral defects. In mosaic group: Autologous osteochondral transplantation was performed. The repair results of the above three groups were compared by histological score, biochemical analysis and biomechanical test to evaluate the effect of repairing rabbit cartilage defects.Results:The compression modulus of neo-cartilage in the 3D print group 2.56±0.30 MPa was close to that of the mosaic group 2.51±0.13 MPa ( P>0.05), and significantly higher than that of freeze-dried group 1.37±0.14 MPa ( F=11.058, P<0.05). The sGAG contents in the 3D print group 14.49±0.7 μg/mg was close to that of the mosaic group 14.98±0.81 μg/mg ( P>0.05), and significantly higher than that of freeze-dried group 8.72±0.73 μg/mg ( F=20.973, P<0.05). However, there was no significant difference in collagen content between the three groups ( P>0.05). The results of ICRS cartilage repair histology score showed that the scores of the 3D print group were close to those of the mosaic group in the matrix, cell distribution, cell viability and subchondral bone ( P>0.05), and were significantly higher than those of freeze-dried group in the surface and cartilage mineralization scores ( F=19.544, P<0.05). Conclusion:Using the new bio-ink to make bone cartilage composite scaffold by 3D bio printing can simplify the construction of tissue-engineered bone cartilage composite tissue in vitro, and can repair cartilage defects in vivo.

Objective:To investigate the relationship between the changes of inflammatory cytokine levels and prognosis of patients with critical coronavirus disease 2019 (COVID-19) undergoing invasive mechanical ventilation (IMV).Methods:A retrospective study was conducted. The clinical date of critical COVID-19 patients undergoing IMV who were hospitalized in Wuhan Union Hospital, Tongji Medical College of Huazhong University of Science and Technology from February 4th to March 25th in 2020 were collected. At the same time, the inflammatory cytokine levels including interleukins (IL-2, IL-4, IL-6, IL-10) and tumor necrosis factor-α (TNF-α) at 48 hours before IMV and 48 hours after IMV of all the patients, as well as the 48 hours after weaning or right before death were recorded. Multivariate unconditional Logistic regression analysis was used to screen the independent risk factors of death during hospitalization.Results:Among the 43 patients, 13 patients improved and 30 died. Compared with the survival group, the patients in the non-survival group were older (years old: 67.6±7.3 vs. 58.5±11.9, P < 0.05), with higher rates of hypertension, diabetes and coronary heart disease (53.3% vs. 15.4%, 63.3% vs. 23.1%, 26.7% vs. 0%, all P < 0.05), and the time from onset to admission to hospital, admission to ICU and IMV were longer (days: it was 9.17±5.00 vs. 5.07±2.49, 17.10±7.11 vs. 12.23±5.05, and 17.90±7.46 vs. 12.61±5.60, respectively, all P < 0.05). The IL-6 and TNF-α levels on 48 hours after IMV in the non-survival patients increased significantly as compared with those before 48 hours and the surviving patients. Especially, the IL-6 levels increased significantly as compared with those at 48 hours after IMV and 48 hours after weaning in the surviving patients [ng/L: 800.00 (194.25, 2 000.00) vs. 22.03 (6.66, 28.21), 3 204.00 (1 264.88, 5 000.00) vs. 5.00 (3.98, 12.27), both P < 0.01]. The IL-10 level before death in the non-survival patients increased significantly as compared with that at 48 hours after weaning in the surviving patients [ng/L: 55.89 (26.07, 100.14) vs. 3.53 (2.76, 12.36), P < 0.05]. There were no significant differences in the levels of IL-2 and IL-4 between the two groups at every time point. The variables of age, basic diseases, the IL-6 level after IMV were included in the multivariate unconditional Logistic regression analysis, which showed that age [odds ratio ( OR) = 0.821, 95% confidence interval (95% CI) was 0.695-0.968], hypertension ( OR = 0.027, 95% CI was 0.002-0.378), diabetes mellitus ( OR = 0.054, 95% CI was 0.005-0.611), coronary heart disease ( OR = 0.042, 95% CI was 0.002-0.968) and the IL-6 level after IMV ( OR = 0.902, 95% CI was 0.819-0.994) were independent risk factors for death during hospitalization in patients with critical COVID-19 undergoing IMV (all P < 0.05). Conclusions:The levels of inflammatory cytokine including IL-6, IL-10, and TNF-α increased significantly with aggravation in critical COVID-19 patients undergoing IMV, especially IL-6. IL-6 was an independent risk factor for death of critical COVID-19 patients undergoing IMV.