Objective To obtain Chinese hamsterovary (CHO) cell line expressing human decay accelerating activity (hDAF) stably and to observe the protective effect of hDAF on heterologous cells under the circumstance of complement activation. Methods The eukaryotic expression vector DAF pcDNA3.1 was constructed and then transfected into CHO cells by lipofection. Monoclones of cells expressing hDAF stably were screened by the method of limiting dilution. hDAF expression was detected by flow cytometry. The decay accelerating activity of hDAF was determined by assay of C3 deposition and 51Cr release. Results The expression vector DAF pcDNA3.1 was successfully constructed, and monoclones of cells expressing hDAF were obtained. CHO cells expressing hDAF could decrease C3 deposition and attenuate the killing effect of activation of the complement system. Conclusion We have obtained CHO cell clones expressing hDAF stably, which is helpful for the further studies of the relationship of the structure with the functions of hDAF.

To evaluated the inhibition effect of local injection of odanacatib on orthodontic relapse.Thirty rats were randomly divided into 2 groups(n =15).The maxillary right first molars of all animals were subjected to orthodontic force and moved mesially.Three weeks later,the force was removed,and the teeth relapsed.The rats of experimental group were received local injections of odanacatib.The control group received saline instead.Tooth movement and relapse were measured when appliances removed after 0 day and 2 weeks.The rats were sacrificed after the 2-week relapse.The microcomputed tomography analysis was performed to quantify the alveolar bone,and the values of bone mineral density(BMD) and bone volume fraction(BVF) were measured.The percentage of relapse in the experimental group was significantly lower than that in the control group(P ＜0.05),and the BMD and BVF of alveolar bone in the experimental group were significantly higher than those in the control group(P ＜0.05).Local injection of odanacatib effectively inhibit the relapse after orthodontic tooth movement in rats.

BACKGROUND:It was found that the ligands and receptors of Notch are both cell membrane surface proteins,which are important proteins to mediate intercellular communication,and the Notch signaling pathway plays a crucial regulatory role in the proliferation and differentiation of mesenchymal stem cells. OBJECTIVE:To review the regulatory mechanism of the Notch signaling pathway on the proliferation and differentiation of mesenchymal stem cells,summarize and clarify the research advance in how the Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells,and provide theoretical support for the future use of stem cells to treat various related diseases. METHODS:By using the computer,the first author searched the relevant studies involving Notch signaling pathway regulation of mesenchymal stem cell proliferation and differentiation on CNKI,Wanfang,VIP,PubMed,Web of Science,and Nature databases with Chinese search terms"mesenchymal stem cells,Notch,Notch signaling pathway,proliferation,differentiation"and the English search terms"mesenchymal stem cells,MSC,Notch,Notch signaling pathway,proliferation,differentiation".Part of the literature was searched in combination with the literature tracing method.Finally,87 articles were included in the review analysis. RESULTS AND CONCLUSION:(1)Notch signaling pathway is a conserved signaling pathway in multicellular organisms,which plays an important role in regulating cell differentiation,proliferation,apoptosis,and the cell cycle by mediating communication between neighboring cells through receptor-ligand binding.(2)Mesenchymal stem cells are a class of adult stem cells with self-proliferative and multi-directional differentiation potential,which can be regulated by external signaling pathways to affect their proliferation and differentiation.Notch signaling pathway,as one of them,when Notch ligands are activated,the Notch proteins will undergo two protein hydrolysis cleavages to release Notch intracellular structural domain NICD,which then enters the nucleus and thus promotes the transcription of target genes to regulate the proliferation and differentiation of mesenchymal stem cells from different sources,such as bone marrow,adipose,and umbilical cord.However,the specific mechanisms that regulate the proliferation and differentiation of mesenchymal stem cells from different tissue sources of the same species are different.(3)The Notch signaling pathway can regulate the differentiation of mesenchymal stem cells into different target cells,but due to different target cells,the expression levels of receptors or ligands in the Notch signaling pathway vary.(4)Clinical targeting of the Notch signaling pathway to promote mesenchymal stem cells for the treatment of various refractory diseases,such as aplastic anemia,severe joint injuries,ischemic strokes,and myocardial infarctions,has a promising application.(5)By exploring the Notch signaling pathway via regulating the expression levels of its receptors and ligands in bone marrow mesenchymal stem cells from rat,mouse,and human,it can be found that the Notch signaling pathway expression levels in the proliferation and differentiation of mesenchymal stem cells from different species origins are also different.(6)The role of mesenchymal stem cells in tissue engineering has been gradually highlighted due to their advantages of safety,low immune rejection,and wide therapeutic prospects.The Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells with a wide range of influencing factors,and subsequent studies should further optimize the influencing factor variables and explore the standardized studies of regulating the proliferation and differentiation of mesenchymal stem cells.

Objective:To assess the influence of a virtual simulation-based training system for composite resin filling on the knowledge acquisition, skill development, and overall learning experience of undergraduate stomatology students.Methods:Forty-one undergraduate students of grade 2019 majoring in stomatology were divided into two groups for preclinical training before their internships: the experimental group used a virtual training system for composite resin filling, while the control group watched instructional videos of the procedure. The two groups were compared for their first performance in composite resin filling during the internships and teaching feedback. The t-test and chi-square test were conducted for data analysis using SPSS 20.0. Results:After repeatedly using the virtual training system for composite resin filling, the students in the experimental group were able to master the key operational points of the procedure, all achieving high scores (an average of 91.77 points) with an average time of 10.39 minutes. During the internship phase, the experimental group and control group showed significant differences in the accuracy rates of instrument selection (85.71% vs. 40.00%), adhesive applying (76.19% vs. 45.00%), and layered filling (100.00% vs. 75.00%; all P<0.05). All the students unanimously recognized the value of the virtual simulation system and expressed their willingness to use it for preclinical training before internships. Nineteen students (90.48%) were satisfied with the learning experience with the virtual simulation training system. Conclusions:The virtual simulation training system for composite resin filling can improve students' understanding and proficiency levels of the technique before clinical internships, facilitating a smoother transition to the internship phase.

Regenerative endodontic procedures (REPs) is a biologic-based treatment modality for immature permanent teeth diagnosed with pulp necrosis. The ultimate objective of REPs is to regenerate the pulp-dentin complex, extend the tooth longevity and restore the normal function. Scientific evidence has demonstrated the efficacy of REPs in promotion of root development through case reports, case series, cohort studies, and randomized controlled studies. However, variations in clinical protocols for REPs exist due to the empirical nature of the original protocols and rapid advancements in the research field of regenerative endodontics. The heterogeneity in protocols may cause confusion among dental practitioners, thus guidelines and considerations of REPs should be explicated. This expert consensus mainly discusses the biological foundation, the available clinical protocols and current status of REPs in treating immature teeth with pulp necrosis, as well as the main complications of this treatment, aiming at refining the clinical management of REPs in accordance with the progress of basic researches and clinical studies, suggesting REPs may become a more consistently evidence-based option in dental treatment.
Humans ; Consensus ; Regenerative Endodontics ; Dental Pulp Necrosis/therapy* ; Dentists ; Professional Role ; Dental Care