Objective:To explore the differences between the Phoenix sepsis scoring system including Phoenix sepsis score (PSS) and Phoenix-8 organ dysfunction score (hereinafter referred to as Phoenix-8) and the commonly used pediatric sepsis scores in evaluating clinical characteristics and prognostic analysis of pediatric patients with severe sepsis diagnosed under traditional standards, namely the diagnostic criteria from the 2005 International Pediatric Sepsis Consensus Conference.Methods:This study was a retrospective observational study. From December 2020 to March 2023, 202 pediatric patients with severe sepsis meeting the inclusion criteria were admitted to the Children's Hospital of Nanjing Medical University. Based on the sepsis diagnostic criteria outlined in the International Consensus Criteria for Pediatric Sepsis and Septic Shock (2024), the pediatric patients were categorized into a sepsis group and a non-sepsis group. Sepsis group was further subdivided into a death subgroup and a survival subgroup based on the outcomes. The age, hospitalization costs, disease outcome indicators (e.g., mortality rate and incidence of septic shock), major organ (e.g., heart, liver, lungs, and kidneys) damage and their correlations, as well as PSS, Phoenix-8 and commonly used pediatric sepsis scores (e.g., pediatric sequential organ failure assessment (pSOFA), pediatric risk of mortality score Ⅲ (PRISM Ⅲ), pediatric logistic organ dysfunction-2 score (PELOD-2), pediatric multiple organ dysfunction score (P-MODS), pediatric critical illness score (PCIS), and pediatric early warning score (PEWS)) were collected and compared. Receiver operating characteristic (ROC) curve and precision-recall curve were plotted to evaluate the predictive ability of PSS, Phoenix-8, and commonly used pediatric sepsis scores for mortality risk in pediatric patients with severe sepsis under traditional standards. Predictive performance was quantified using the area under the ROC curve (AUROC). Univariate logistic regression analysis was employed to quantify the odds ratios of PSS and Phoenix-8 for predicting mortality risk. Patients with severe sepsis under traditional standards were further stratified into subgroups based on complications and comorbidities, including central nervous system (CNS) diseases, multiple infections, cardiovascular system diseases, shock, and malignancies. The Hosmer-Lemeshow goodness-of-fit test was used to assess calibration of PSS and Phoenix-8, and the DeLong test was used to compare whether there were statistically significant differences in the AUROC of PSS and Phoenix-8 for predicting mortality risk among different subgroups of pediatric patients. Results:Compared with those in non-sepsis group, pediatric patients in sepsis group were significantly older ( Z=-2.92, P<0.05) with higher incidences of septic shock and mortality, hospitalization costs, PRISM Ⅲ, PEWS, pSOFA, PELOD-2, PSS, and Phoenix-8 (with χ2 values of 21.28 and 13.64, respectively, Z values of -1.99, -5.33, -5.10, -8.55, -6.91, -10.98, and -9.93, respectively, P<0.05), and lower PCIS ( Z=-3.34, P<0.05). Compared with those in survival subgroup, hospitalization costs, PSS, Phoenix-8, PRISM Ⅲ, PEWS, pSOFA, PELOD-2, and P-MODS of pediatric patients in death subgroup was significantly higher (with Z values of -2.50, -3.50, -2.47, -5.11, -3.84, -2.94, -3.61, and -3.04, respectively, P<0.05). Compared with those in survival subgroup, the incidences of lung damage and liver damage of pediatric patients in death subgroup were also significantly higher (with χ2 values of 6.20 and 10.94, respectively, P<0.05), and 64.7% (97/150) of patients exhibited two or more concurrent organ damage. For predicting mortality risk in pediatric patients with severe sepsis under traditional standards, the AUROC values for PRISM Ⅲ, PCIS, PEWS, pSOFA, PELOD-2, P-MODS, PSS, and Phoenix-8 were approximately 0.70, with optimal cutoff values of 17.5, 91.0, 5.5, 4.5, 2.5, 4.5, 3.5, and 4.5, respectively; PELOD-2 demonstrated the highest sensitivity (0.83); while PRISM Ⅲ, PSS, and Phoenix-8 showed high specificity (>0.80). Univariate logistic regression analysis showed that for every 1-point increase in the PSS within 24 hours of pediatric intensive care unit admission, the relative risk of mortality increased by 63.7% (with odds ratio of 1.64, 95% confidence interval of 1.34-1.99, P<0.05). Similarly, for every 1-point increase in the Phoenix-8, the relative risk of mortality increased by 37.5% (with odds ratio of 1.38, 95% confidence interval of 1.18-1.60, P<0.05). The AUROC values (around 0.80) of PSS and Phoenix-8 for predicting mortality risk in pediatric patients with severe sepsis combined with CNS diseases, multiple infections, and cardiovascular system diseases were relatively high. In contrast, the AUROC values (0.60-0.80) for predicting mortality risk in pediatric patients with severe sepsis combined with shock or malignant tumors were moderate. All models passed the Hosmer-Lemeshow goodness-of-fit test ( P>0.05). The DeLong test indicated no statistically significant differences in predictive ability between PSS and Phoenix-8 across subgroups of pediatric patients ( P>0.05). Conclusions:PSS and Phoenix-8 exhibited higher specificity than most of the commonly used pediatric sepsis scores in predicting mortality risk under traditional standards. Both scores performed much better in predicting the mortality risk in pediatric patients with severe sepsis combined with CNS diseases, multiple infections, and cardiovascular system diseases.

Periodontal bone defects, primarily caused by periodontitis, are highly prevalent in clinical settings and manifest as bone fenestration, dehiscence, or attachment loss, presenting a significant challenge to oral health. In regenerative medicine, harnessing developmental principles for tissue repair offers promising therapeutic potential. Of particular interest is the condensation of progenitor cells, an essential event in organogenesis that has inspired clinically effective cell aggregation approaches in dental regeneration. However, the precise cellular coordination mechanisms during condensation and regeneration remain elusive. Here, taking the tooth as a model organ, we employed single-cell RNA sequencing to dissect the cellular composition and heterogeneity of human dental follicle and dental papilla, revealing a distinct Platelet-derived growth factor receptor alpha (PDGFRA) mesenchymal stem/stromal cell (MSC) population with remarkable odontogenic potential. Interestingly, a reciprocal paracrine interaction between PDGFRA⁺ dental follicle stem cells (DFSCs) and CD31⁺ Endomucin⁺ endothelial cells (ECs) was mediated by Vascular endothelial growth factor A (VEGFA) and Platelet-derived growth factor subunit BB (PDGFBB). This crosstalk not only maintains the functionality of PDGFRA⁺ DFSCs but also drives specialized angiogenesis. In vivo periodontal bone regeneration experiments further reveal that communication between PDGFRA⁺ DFSC aggregates and recipient ECs is essential for effective angiogenic-osteogenic coupling and rapid tissue repair. Collectively, our results unravel the importance of MSC-EC crosstalk mediated by the VEGFA and PDGFBB-PDGFRA reciprocal signaling in orchestrating angiogenesis and osteogenesis. These findings not only establish a framework for deciphering and promoting periodontal bone regeneration in potential clinical applications but also offer insights for future therapeutic strategies in dental or broader regenerative medicine.
Receptor, Platelet-Derived Growth Factor alpha/metabolism* ; Humans ; Neovascularization, Physiologic/physiology* ; Dental Sac/cytology* ; Single-Cell Analysis ; Transcriptome ; Mesenchymal Stem Cells/metabolism* ; Bone Regeneration ; Animals ; Dental Papilla/cytology* ; Periodontium/physiology* ; Stem Cells/metabolism* ; Regeneration ; Angiogenesis

Objective:To explore the differences between the Phoenix sepsis scoring system including Phoenix sepsis score (PSS) and Phoenix-8 organ dysfunction score (hereinafter referred to as Phoenix-8) and the commonly used pediatric sepsis scores in evaluating clinical characteristics and prognostic analysis of pediatric patients with severe sepsis diagnosed under traditional standards, namely the diagnostic criteria from the 2005 International Pediatric Sepsis Consensus Conference.Methods:This study was a retrospective observational study. From December 2020 to March 2023, 202 pediatric patients with severe sepsis meeting the inclusion criteria were admitted to the Children's Hospital of Nanjing Medical University. Based on the sepsis diagnostic criteria outlined in the International Consensus Criteria for Pediatric Sepsis and Septic Shock (2024), the pediatric patients were categorized into a sepsis group and a non-sepsis group. Sepsis group was further subdivided into a death subgroup and a survival subgroup based on the outcomes. The age, hospitalization costs, disease outcome indicators (e.g., mortality rate and incidence of septic shock), major organ (e.g., heart, liver, lungs, and kidneys) damage and their correlations, as well as PSS, Phoenix-8 and commonly used pediatric sepsis scores (e.g., pediatric sequential organ failure assessment (pSOFA), pediatric risk of mortality score Ⅲ (PRISM Ⅲ), pediatric logistic organ dysfunction-2 score (PELOD-2), pediatric multiple organ dysfunction score (P-MODS), pediatric critical illness score (PCIS), and pediatric early warning score (PEWS)) were collected and compared. Receiver operating characteristic (ROC) curve and precision-recall curve were plotted to evaluate the predictive ability of PSS, Phoenix-8, and commonly used pediatric sepsis scores for mortality risk in pediatric patients with severe sepsis under traditional standards. Predictive performance was quantified using the area under the ROC curve (AUROC). Univariate logistic regression analysis was employed to quantify the odds ratios of PSS and Phoenix-8 for predicting mortality risk. Patients with severe sepsis under traditional standards were further stratified into subgroups based on complications and comorbidities, including central nervous system (CNS) diseases, multiple infections, cardiovascular system diseases, shock, and malignancies. The Hosmer-Lemeshow goodness-of-fit test was used to assess calibration of PSS and Phoenix-8, and the DeLong test was used to compare whether there were statistically significant differences in the AUROC of PSS and Phoenix-8 for predicting mortality risk among different subgroups of pediatric patients. Results:Compared with those in non-sepsis group, pediatric patients in sepsis group were significantly older ( Z=-2.92, P<0.05) with higher incidences of septic shock and mortality, hospitalization costs, PRISM Ⅲ, PEWS, pSOFA, PELOD-2, PSS, and Phoenix-8 (with χ2 values of 21.28 and 13.64, respectively, Z values of -1.99, -5.33, -5.10, -8.55, -6.91, -10.98, and -9.93, respectively, P<0.05), and lower PCIS ( Z=-3.34, P<0.05). Compared with those in survival subgroup, hospitalization costs, PSS, Phoenix-8, PRISM Ⅲ, PEWS, pSOFA, PELOD-2, and P-MODS of pediatric patients in death subgroup was significantly higher (with Z values of -2.50, -3.50, -2.47, -5.11, -3.84, -2.94, -3.61, and -3.04, respectively, P<0.05). Compared with those in survival subgroup, the incidences of lung damage and liver damage of pediatric patients in death subgroup were also significantly higher (with χ2 values of 6.20 and 10.94, respectively, P<0.05), and 64.7% (97/150) of patients exhibited two or more concurrent organ damage. For predicting mortality risk in pediatric patients with severe sepsis under traditional standards, the AUROC values for PRISM Ⅲ, PCIS, PEWS, pSOFA, PELOD-2, P-MODS, PSS, and Phoenix-8 were approximately 0.70, with optimal cutoff values of 17.5, 91.0, 5.5, 4.5, 2.5, 4.5, 3.5, and 4.5, respectively; PELOD-2 demonstrated the highest sensitivity (0.83); while PRISM Ⅲ, PSS, and Phoenix-8 showed high specificity (>0.80). Univariate logistic regression analysis showed that for every 1-point increase in the PSS within 24 hours of pediatric intensive care unit admission, the relative risk of mortality increased by 63.7% (with odds ratio of 1.64, 95% confidence interval of 1.34-1.99, P<0.05). Similarly, for every 1-point increase in the Phoenix-8, the relative risk of mortality increased by 37.5% (with odds ratio of 1.38, 95% confidence interval of 1.18-1.60, P<0.05). The AUROC values (around 0.80) of PSS and Phoenix-8 for predicting mortality risk in pediatric patients with severe sepsis combined with CNS diseases, multiple infections, and cardiovascular system diseases were relatively high. In contrast, the AUROC values (0.60-0.80) for predicting mortality risk in pediatric patients with severe sepsis combined with shock or malignant tumors were moderate. All models passed the Hosmer-Lemeshow goodness-of-fit test ( P>0.05). The DeLong test indicated no statistically significant differences in predictive ability between PSS and Phoenix-8 across subgroups of pediatric patients ( P>0.05). Conclusions:PSS and Phoenix-8 exhibited higher specificity than most of the commonly used pediatric sepsis scores in predicting mortality risk under traditional standards. Both scores performed much better in predicting the mortality risk in pediatric patients with severe sepsis combined with CNS diseases, multiple infections, and cardiovascular system diseases.

Objective To investigate the effects of inhibiting KDM2A gene on the proliferation,invasion and migration of liver cancer cells and its possible regulatory mechanism.Methods Forty pairs of HCC tissues and their adjacent normal counterparts were collected from 2014 to 2017 in Tongji Hospital,Tongji Medical College Affiliated to Huazhong University of Science and Technology.Human liver cancer cell lines HepG2,Huh7,HCCLM3,MHCC-97H and normal liver cells LO2 were cultured in vitro.The mRNA and protein expression levels of KDM2A in HCC tissues and cells were detected by qRT-PCR and Western blotting.Huh7 cells were taken and set up as follows:(1)si-NC group(transfected with si-NC)and si-KDM2A group(transfected with si-KDM2A);(2)mimic-NC group(transfected with mimic-NC),miRNA-29a-3p mimic group(transfected with miRNA-29a-3p mimic),inhibitor-NC group(transfected with inhibitor-NC)and miRNA-29a-3p inhibitor group(transfected with miRNA-29a-3p inhibitor).The mRNA and protein expression levels of KDM2A were detected by qRT-PCR and Western blotting.The invasion and migration of cells were detected by Transwell,the proliferation of cells was detected by CCK-8 methods.The online databases TargetScan,miRDIP,miRWalk,Starbase and miRDB were used to predict the binding sites of KDM2A and miR-29a-3p.The KDM2A 3'-UTR(WT)or KDM2A 3'-UTR(MUT)report plasmid was co-transfected with NC-miRNA or miR-29a-3p mimics respectively for 48 h in 293T cells,and the luciferase activity was detected by the luciferase reporter gene detection system.Results Compared with adjacent normal counterparts,the relative mRNA and protein expression levels of KDM2A in HCC tissues increased significantly(P＜0.05).Compared with LO2,the relative mRNA and protein expression levels of KDM2A in HepG2,Huh7,HCCLM3 and MHCC-97H increased significantly(P＜0.05).Compared with si-NC group,the proliferation,invasion and migration of Huh7 cells in si-KDM2A group decreased significantly(P＜0.05 or P＜0.01).The analysis results of TargetScan,miRDIP,miRWalk,Starbase and miRDB showed that there were binding sites between KDM2A and miR-29a-3p.The results of the dual luciferase reporter assay showed that miR-29a-3p mimic significantly reduced KDM2A-MUT luciferase activity(P＜0.01).After overexpression of miRNA-29a-3p,the relative mRNA and protein expression levels of KDM2A were decreased(P＜0.01),the proliferation,invasion and migration abilities were decreased(P＜0.05)in Huh7 cells.After inhibiting the expression of miRNA-29a-3p,the relative mRNA and protein expression levels of KDM2A were increased(P＜0.05),the proliferation,invasion and migration abilities were enhanced(P＜0.05)in Huh7 cells.Conclusion Inhibiting the expression of KDM2A can reduce the proliferation and migration ability of Huh7 cells.miR-29a-3p may be the upstream regulator of KDM2A and participate in the occurrence and development of hepatocellular carcinoma.

Objective:To explore the efficacy and safety of domestic bortezomib in combination with lenalidomide and dexamethasone in the treatment of newly diagnosed multiple myeloma (NDMM) .Methods:This multicenter, prospective, single-arm clinical study included 126 patients with NDMM admitted to seven hospitals between December 2019 and January 2022. All patients received domestic bortezomib in combination with lenalidomide and dexamethasone (BLD regimen), and the efficacy, prognostic factors, and safety were analyzed.Results:Among the 126 patients with NDMM, 118 completed four cycles of treatment, with an overall response rate (ORR) of 93.22% (110/118) and a ≥very good partial response (VGPR) rate of 68.64% (81/118). Ultimately, 114 patients completed at least eight cycles of treatment, with an ORR of 92.98% (106/114) and a ≥VGPR rate of 77.19% (88/114). Eighteen patients underwent autologous hematopoietic stem cell transplantation after completing 6-8 cycles of the BLD regimen, with an ORR of 100% (18/18) and a ≥VGPR rate of 88.9% (16/18). The proportion of patients achieving ≥VGPR increased with the treatment duration, and factors such as staging and age did not significantly affect efficacy. Single-factor analysis showed that R2-ISS stage Ⅲ/Ⅳ, blood calcium >2.27 mmol/L, and failure to achieve VGPR after six cycles were adverse prognostic factors for progression-free survival (PFS) ( P<0.05), whereas failure to achieve VGPR after six cycles was an adverse prognostic factor for overall survival (OS) ( P<0.001). Multifactor analysis demonstrated that failure to achieve VGPR after six cycles is an independent adverse prognostic factor for PFS ( P=0.002). The incidence of hematologic adverse reactions was 16.7% (19/114), and nonhematologic adverse reactions were mainly mild to moderate, with no significant cardiac or renal adverse reactions observed. Conclusion:The BLD regimen is effective in treating NDMM, in which patients with high-risk genetic features are still achieving a high ≥VGPR rate, and the overall safety is good.

Purpose: The rate of interval colorectal cancer (iCRC) is now accepted as a key performance indicator of organized colorectal cancer (CRC) screening programs. We aimed to examine the association between endoscopist volumes and the rate of iCRC among individuals with a positive fecal immunochemical test (FIT) within a nationwide population-based CRC screening program. Materials and Methods: Individuals aged ≥ 50 years who underwent colonoscopy after a positive FIT from January 1, 2019 until December 31, 2020 in the Korean National Cancer Screening Program (KNCSP) were enrolled. We converted the data into per-endoscopist screening results, calculated the iCRC rates per endoscopist, and compared them to the previous year’s annual volume that was divided into five groups (V1, 1-9; V2, 10-29; V3, 30-59; V4, 60-119; V5, ≥ 120). Results: A total of 10,412 endoscopists performed 216,907 colonoscopies. Overall, the average rate of iCRC per endoscopist was 8.46 per 1,000 examinations. Compared with the group with the highest volume (V5 group), the rate of iCRC was 2.21 times higher in the V1 group. Similar trends were observed in the other groups (V2: relative risks [RR], 2.15; 95% confidence interval [CI], 1.57 to 2.94; V3: RR, 1.56; 95% CI, 1.15 to 2.13; V4: RR, 1.18; 95% CI, 0.83 to 1.67). Conclusion The findings emphasize that endoscopists with lower procedure volumes have higher risks of interval cancer being missed or undetected. To maximize the preventative impact of colonoscopy for CRC, this issue should be addressed by monitoring endoscopist volumes and variations in performances.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Objective: To prepare a composite membrane by chitosan/β-sodium glycerophosphate(CS/β-GP) thermosensitive hydrogel combined with stromal cell derived factor-1(SDF-1) and observe its biological characteristics in vitro. Methods: Different doses of SDF-1 were added into CS/β-GP solution and then the thermosensitive gel time was measured. The SDF-1/CS/β-GP solution was membrane paved and dried to prepare composite membranes. The morphological characteristics were observed by scanning electron microscope(SEM). Composite membranes were placed into cell culture medium, and the supernatant(n=3) was extracted after standing at 6, 12, 24, 36, 48, 60 h, respectively. The concentration of SDF-1 in the solution was measured. Bone mesenchymal stem cells(BMSCs) were cultured in the Transwell room, and the composite membranes containing different concentrations of SDF-1 were placed in the lower chamber. There were four groups(n=3): Group M0 used CS/β-GP membrane(control group), Group M1, M2, M3 used SDF-1/CS/β-GP membrane(SDF-1 was 100, 200, 400 ng/mL respectively). After culture for 6, 12 and 24 h, the cells under the membrane were preserved and Giemsa stained and counted. The absorbance(OD) value was measured by MTT method to calculate the cell proliferation rate. SPSS 19.0 was used for multi-factor analysis of variance. Results : After adding a certain amount of SDF-1 into CS/β-GP solution, the gel time did not change significantly(P>0.05). The SDF-1/CS/β-GP membrane was translucent and porous at 37 ℃. In this experiment, the volumic mass of SDF-1 released by SDF-1/CS/β-GP composite membrane increased gradually with the experimental time(P<0.01). Transwell cell chemotaxis test showed that the number of BMSCs cells with directional migration increased with the prolongation of observation time(P<0.01) and the increase of SDF-1 volumic mass(P<0.01). In MTT test, the OD value of migration cell solution increased with the prolongation of time(P<0.01) and the increase of SDF-1 volumic mass(P<0.01). Conclusion The SDF-1/CS/β-GP composite membrane has a porous structure and biological activity of chemotactic BMSCs directional migration. It is a potential membrane for guided tissue regeneration.

Objective To investigate the effect of caloric restriction(CR)on myocardial ischemia/reperfusion injury(MI/RI)in mice and its mechanism.Methods C57 mice were randomly divided into normal diet group(AL group,free feeding)and CR group(diet decreased by 10% every 2 weeks)for 8 weeks and monitored for weight changes.Each group was divided into sham operation group and MI/RI group,total 4 groups,AL + Sham group,AL + I/R group,CR + Sham group and CR + I/R group).The left anterior descending coronary artery was ligated for 30 minutes and then reperfused for 24 hours in mice of MI/RI group and mice in Sham group were only threaded but not ligated.The mice were determined for myocardial ischemia and infarct size by Evans blue/TTC staining,observed for the pathology of myocardium by HE staining,determined for the activities of lactate dehydrogenase(LDH),superoxide dismutase(SOD)and the contents of creatine kinase-MB(CK-MB)and malondialdehvde(MDA)in myocardium by the corresponding kits,determined for serum levels of IL-1β and IL-18 by ELISA and detected for the expression of pyroptosis-associated proteins in myocardium by Western blot.Results After 8weeks,the weights of mice in CR group[(24.54 ± 0.41)g]were significantly lower than those in AL group[(31.46 ±0.25)g](t = 14.34,P<0.05).Compared with those in AL + I/R group,the area of myocardial ischemia in CR + I/R group showed no significant difference(t = 0.783 0,P>0.05),while the area of myocardial infarction decreased significantly(t = 7.250,P<0.01);The myocardial arrangement was relatively neat,and the degree of pathological changes was obviously reduced;LDH activity,CK-MB and MDA contents decreased significantly(t = 4.331,2.875 and 5.343 respectively,each P<0.05),while SOD activity increased significantly(t = 4.211,P<0.05);Serum levels of IL-1β and IL-18 decreased significantly(t = 3.375 and 4.266 respectively,each P<0.05);The expression levels of nod-like receptor protein 3(NLRP3),gasdermin D(GSDMD),apoptosis-associated speckle-like protein(ASC)and caspase-1 significantly decreased(t = 3.412,3.420,3.480 and 2.585 respectively,each P<0.05).Conclusion CR alleviated MI/RI in mice,and its mechanism was related to the inhibition of cardiac pyroptosis.