Objective: To compare the phagocytosis ability of Aa by peripheral mononuclear cells(Mo), alveolar macrophage(AM), peritoneal macrophage (PM) and kuffer cells (KC). Meathods: Mo, AM, PM and KC from 3 healthy New Zealand rabbits were isolated and purificated. Aa was labeded with fluorescein isothiocyanate (FITC). Monocytes/macrophages were infected with FITC-Aa in the ratio of 25:1(25 bacteria:1 cell). The phagocytosis rates and mean fluorescent intensity (MFI) were detected by the flow cytometry at 30 min, 1 h, 1.5 h. And phagocytic index was calculated. Result: Within 1.5 h, the AM, PM phagocytic index were rise as the time increase; the phagocytosis ability of Mo and KC reached the peak at 1 h; Obvious difference of phagocytosis between Mo, AM, PM and KC was observed. At 30 min, the phagocytic index is : AM and PM＞Mo, KC; at 1 h, AM＞PM＞Mo and KC; at 1.5 h, AM＞PM＞KC＞Mo. Conclusion: The different phagocytosis of Aa by monocytes/macrophages of various tissues may be the important reason why there are different effects on different parts in the periodontitis.

［Abstract］Objective: To investigate the single nucleotide polymorphism with significant association on the head and neck cancer (HNC) risk in a Chinese Han population．Methods：We genotyped five variants (rs1494961, rs1229984, rs1789924, rs971074 and rs4767364) in a case-control study with 397 HNC cases and 900 controls, using the TaqMan allelic discrimination assay. Results：We found that rs1229984 at 4q23 significantly increased the risk of HNC [adjusted odds ratio (OR) =1.34, 95% con?dence interval (CI) = 1.05-1.71]. By contrast，no significant association was observed between the other four single nucleotide polymorphisms (SNPs) and HNC risk．Conclusion：These findings suggest that rs1229984 at 4q23 may serve as candidate marker for HNC susceptibility in a Chinese population.

Objective: To explore the possibility of ectopically implanted epithelium caused by micro-implant. Methods: Using Beagle dogs as experimental animal, AAV2-GFP were injected in the gingiva of implantation area. The dogs were euthanized at 0 d, and the bone specimen were made into serial slices. Fluorescences of cytokeratin antibody and GFP expressed by AAV2 were detected to demonstrate the ectopically implanted epithelium around the micro-implant. Results: Ectopically implanted gingivae epithelium wasn't found at the bone-implant interface by our two means of detection. Conclusions: No possibility of ectopically implanted epithelium caused by the placement of micro-implant was found.

Objective To construct overexpression vectors targeting rat HDAC8 gene and study the transfection effect of HDAC8 in bone marrow stromal cells ( BMSCs ). Methods The HDAC8 gene was insert into plasmid pGC-FU of lentiviral vector. The plasmid was detected by DNA sequencing. The recombined plasmid pGC-FU-HDAC8 was transfected into 293 cell line. Virus yielded by 293T cell was transfected into rat BMSCs. The expression of HDAC8 was detected by Western bolt. Results The HDAC8 were correctly cloned into the pGC-FU plasmid and confirmed by DNA sequencing. Our result of Western blot showed that pGC-FU-HDAC8 significantly up regulated the expression of HDAC8 in rat BMSCs. Conclusion overexpression vector targeting rat HDAC8 gene had been constructed successfully and efficiently up-regulated the expression of HDAC8 in rat BMSCs.

[Abstract] Objective：To evaluate the effects of 17β-estrodial on the expression of receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) in human stem cells from apical papillae (SCAPs). Methods：SCAPs cultured in L-MEM containing 10 μmol/L alcohol, L-MEM containing 0.1 μmol/L 17β-estrodial for 3 days and 7 days were respectively collected to evaluate the expression of RANKL and OPG at the gene or protein level by real-time RT-PCR and Western blotting. Results：17β-estrodial can enhance the expression of OPG and downregulate the expression of RANKL. Conclusions：17β-estrodial may regulate the odonto/osteogenic and odonto/osteoclastic potential through RANKL/OPG system.

[Abstract] Objective：To investigate the role semaphorin3A(SEMA3A) and its receptor neuropilin-1(NRP-1) play in the intriguing process that tumor grow without nervous tissue, we establish the model of cocutures of squamous cell carcinoma 25 (SCC25) and rat’s dorsal root ganglion(DRG). Methods: We tested the expression of SEMA3A and NRP-1 respectively in SCC25 and rat’s DRG. And then a model of cocutures of SCC25 and rat’s DRG was established. In the vitro cocultures, the difference of the DRG’s sprouting was observed when the medium treat with or without the antagonist of NRP-1. Results: Both the expression of SEMA3A in SCC25 and the expression of NRP-1 in rat’s DRG were positively detected, and the coculture showed that the rat’s DRG treating with the antagonist of NRP-1 sprouts better. Conclusions: SEMA3A and its receptor NRP-1 may play an important role in the process that tumor grow without nervous tissue.

Objective：To observe the expression of three members in the RUNX family, namely RUNX1 ,RUNX2,RUNX3 in mandibular first molars of Balb/c mice at different stages prenatally and postnatally, and explore the mechanism of Runt-related transcription factor in tooth development of Balb/c mice. Methods：The mandibles of Balb/c mice containing mandibular first molars or their germs were isolated at embryonal 19.5 day and postnatal 0、6、14、28 days respectively. The isolated tissues were processed by HE staining and immunohistochemistrical method to detect the expression of RUNX1 ,RUNX2,RUNX3 in tooth development．Results：RUNX1 was detected at E19.5 day in the germs and progressively increased at P 0、6、14、28 days. The expression of RUNX2 was granularly at E19.5 day and P0 day. The lowest point was detected at P6 day, and an uprising positive trend was showed at P14 day and 28 day. Expression of RUNX3 showed a rising trend in dentine at P6、14、28 days but negative at E19.5 day and P0 day. Conclusions：It can be speculated that RUNX1 participates in differentiation of ameloblasts and odontoblasts and maturation of dentine. RUNX2 is mostly correlated with the maturation of dentin．RUNX3 is related to maturation of dentine and formation of tooth shape in later period.

【Abstract】 Objective To improve the knowledge of the clinicopathologic features of Kimura disease(KD). Methods seven cases of Kimura disease were evaluated by light microscopy and immunohistochemistry. Results All the 7 cases were male, the age of onset were from 21 to 73 years. The typical clinical presentation was characterizde by painless subcutaeous and major salivary glands in the head and neck.The pathological characterisitics of KD were lymphoid tissue hyperplasia with prominent lymphoid follicles,enlargement of germinal center, conspicuous eosinophils infiltration and capillary proliferation. Immunohistochemical study in KD revealed B cells in the lymphoid follicles and mostly T cells in the interfollicular regions. Conclusions KD is an uncommon lymphoid tissue hyperplasia. It should be differentiated from tumor abundant with lymph tissue. The histopathologic diagnosis of KD is important.

Objective To evaluate the difference in microbial diversity between ECC children before treatment and after treatment by means of a cultivation-independent approach called denaturing gradient gel electrophoresis (DGGE). Methods 22 children aged 3-5 years old from Peking University Yandong Kindergarten were selected for this study. Saliva samples were collected before treatment and 2 weeks after treatment. Total microbial genomic DNA was isolated from those subjects, and a portion of the 16S rRNA gene locus was PCR amplified by using universal primers. Then the PCR products were isolated using DGGE method. Results The mean species richness of the bacterial population was greater in the samples collected after treatment (28±4.1) than in those before treatment (23±2.9). The difference was statistically significant (P<0.01). Phylogenetic analysis show similarity within the groups while difference between groups. Conclusions PCR-DGGE method can visualize the diversity and complexity of the microbial biota associated with caries and monitor the dynamic changes of the bacterial compositions.

[Abstract] Objective：To investigate the bacteriostasis effect of Longliqi DL toothpaste containing dextranase and lysozyme on several species of oral bacteria. Methods：The adhesiveness of S. mutans(Sm) was determined by Dentocult SM test; the bacteriostasis to A. actinomycetemcomitans(Aa), P. gingivalis(Pg) and A. viscosus(Av) were observed by agar dispersion method. Results：The aqueous solutions of dextranase and the toothpaste reduced adhesion of Sm to the Dentocult SM test strip; the aqueous solutions of lysozyme produced clear inhibition zones of Aa, Pg and Av, and the diameter of the inhibition zones increased along with the increasing of concentration of lysozyme; the toothpaste produced clear inhibition zones of Pg and Av and unclear inhibition zone of Aa. Conclusions：Dextranase and the toothpaste reduce the adhesiveness of Sm; lysozyme and the toothpaste has in vitro bacteriostasis effect on several species of oral microorganism.

Bone regeneration and reconstruction relies on the sequential expression of various growth factors and their synergetic effect. Taking advantages of the synergetic effect of different growth factors is currently becoming a reasonable alternative to promote bone regeneration. This paper represents the application of all-trans retinoic acid (ATRA) and bone morphogenetic protein (BMP) to promote bone regeneration on the present.