The immune microenvironment plays a crucial role in bone remodeling around implants.The complement system,a key com-ponent of the immune system,significantly influences bone formation and resorption.However,the activation of the complement system varies depending on the stages of implant placement and the types of implant materials.This review discusses the complement system,its activation pathways,its effects on bone remodeling,and the impact of various stages of implant placement and different materials on com-plement system activation.These insights would help develop strategies for promoting bone remodeling around implants through targeted regulation of the complement microenvironment in the vicinity of the implanted material.

The immune microenvironment plays a crucial role in bone remodeling around implants.The complement system,a key com-ponent of the immune system,significantly influences bone formation and resorption.However,the activation of the complement system varies depending on the stages of implant placement and the types of implant materials.This review discusses the complement system,its activation pathways,its effects on bone remodeling,and the impact of various stages of implant placement and different materials on com-plement system activation.These insights would help develop strategies for promoting bone remodeling around implants through targeted regulation of the complement microenvironment in the vicinity of the implanted material.

Objective:To investigate the effects of low-dose radiation(LDR)combined with human telomerase reverse transcriptase C-terminal polypeptide 27(hTERTC27)overexpression on the proliferation and apoptosis of lung cancer A549 cells,and to observe the in vivo antitumor effects of LDR combined with C27.Methods:The pEgr-hTERTC27 plasmid was transfected into human non-small cell lung cancer(NSCLC)A549 cells and mouse Lewis lung carcinoma(LLC)cells.Cells stably expressing C27(A549-C27 and LLC-C27)were screened by G418 selection.The cells were divided into six groups:conventional radiation(CONV-RT)group(A549-Con),LDR group(A549-Low),C27 group(A549-C27),CONV-RT combined with C27 group(A549-C27-Con),LDR combined with C27 group(A549-C27-Low),and control group(A549-Mock).The irradiation dose in LDR group was only 36%of CONV-RT group.MTT assay was used to detect cell proliferation,and flow cytometry was used to measure cell apoptosis.LLC cell-transplanted tumor model in mice was established through subcutaneous implantation,and the animal experiment groups were similar with cell experiments.Tumor growth,volume,and mass were recorded in each group.Muscle infiltration near the transplanted tumors was observed using H-E staining.Results:Compared with A549-Mock group,the proliferative activity of A549-Con and A549-Low group was significantly decreased(all P<0.01).Furthermore,the proliferation activity of A549-C27-Con and A549-C27-Low cells was significantly lower than that of A549-C27 cells(all P<0.01).Compared with A549-Mock,the apoptosis rates were significantly higher in A549-Con and A549-Low groups(P<0.01);however,no significant difference in apoptosis rates were observed among A549-C27,A549-C27-Con and A549-C27-Low groups(all P>0.05).In tumor-bearing mice,both CONV-RT and LDR significantly reduced tumor mass compared with unirradiated mice(all P<0.01).In addition,the tumor mass and local infiltration were significantly reduced in both LLC-C27-Low and LLC-C27-Con groups.Conclusion:LDR combined with C27 achieves similar antitumor effects to CONV-RT alone while reducing the total radiation dose in NSCLC.Moreover,LDR and C27 peptide synergize in their anti-tumor effects,with their combination reducing local tumor infiltration in transplanted tumor models.

Objective To detect the changes in vertebral marrow fat fraction (MFF) using T2 *-corrected water-fat MRI and to analyze the relationships between MFF with bone biomarkers of non-dialysis chronic kidney disease (CKD).Methods 78 CKD patients were divided into five groups according to the eGFR and underwent water/fat MRI to obtain MFF.The reliability of MFF measurements by two radiologists was assessed with intra-class correlation coefficient (ICC).Serum calcium,phosphorus,alkaline phosphatase,osteocalcin,intact parathyroid hormone and 25(OH)D3 were determined.Results Mean CV for MFF measurements reproducibility was 2.37％.The inter-observer agreement for MFF was excellent (ICC=0.901).The ICC for each intra-observer agreement was excellent (ICC=0.959 and 0.948,respectively).There were statistical differences in MFF among five groups of CKD.Changes of MFF were earlier than those of serum calcium,phosphorus,parathyroid hormone,alkaline phosphatase and osteocalcin.MFF was positively correlated with serum phosphorus (r =3.011,P =0.003),parathyroid hormone (r=3.852,P＜0.001),and negatively associated with calcium (r=-2.767,P=0.017),25(OH)D3 (r=6.032,P＜0.001),eGFR (r=-5.104,P＜0.001),respectively.Multivariable regression analysis showed MFF was negatively correlated with 25(OH)D3(Sβ=-0.343)and eGFR(S(S=-0.284,P＜0.001).Conclusion CKD patients had higher marrow fat.T2 *-corrected water fat MRI could serve as a useful tool to quantify marrow fat content for CKD patients.

OBJECTIVE:To extract and identify the volatile components of the roots of Polyalthia nemoralis,and to evaluate its biological activity in vitro. METHODS:Supercritical CO2 extraction (SFE-CO2) was performed to extract volatile compounds from the roots of P. nemoralis,and the volatile components were separated and determined by GC-MS. Human hepatic cancer Huh-7 cells were cultured with 0(blank control),5,10,20,30,40 and 50 μg(medicinal material)/ml extract for 24 h,and then MTT assay was used to detect the inhibitory effect of the extracts on cells. Relative cell viability and IC50 were calculated. The an-ti-bacterial activities of extract to Staphylococcus aureus,Methicillin-resistant Staphylococcus aureus,Enterococcus faecalis and oth-er strain were determined by Kirby-bauer method and broth dilution method. RESULTS:Forty compounds were identified from the SFE-CO2 extracts from the roots of P. nemoralis. The main constituents were(Z,Z,Z)-9,12,15-octa-decatrien-1-ol,glycerin,cinna-maldehyde,n-hexadecanoic acid and eugenol. Compared with blank control group,SFE-CO2 extracts from the roots of P. nemoralis 5 μg(medicinal material)/ml and above showed significant inhibitory effect on cell growth(P<0.05),and the inhibitory effect was strengthened as the concentration of extracts increased,IC50 values was 5.2 μg(medicinal material)/ml. However,the supercritical extract didn't showed antibacterial activity against three microorganisms in 2 kinds of antibacterial tests. CONCLUSIONS:SFE-CO2 and GC-MS method can effectively extract and identify volatile components of the roots of P. nemoralis,and supercritical extracts can inhibit the viability of cells but have no antibacterial activity.