Objective: To determine the distribution of Actinobacillus actinomycetemcomitans (Aa) in subgingival plaques in the patients with chronic periodontitis(CP). Methods: Samples of subgingival plaque were detected for Aa distribution by oligonucleotide probe from 60 sites of CP patients and 10 healthy sites of healthy people.Each sample was obtained from each site of each people. Results: Aa was detected in 19 out of 60 diseased sites(31.67%); Aa wasn't detected in healthy sites.The age(28.68±7.33) of Aa-positive patients was younger than that (44.48±12.48) of Aa-negative patients(P<0.05).Conclusion: Aa is possibly to cause chronic periodontal infection in younger people.

Objective:To evaluate the usefulness of Periocheck in clinical application before and after periodontal curettage.Methods:Periocheck was applied in 65 sites in 65 adult patients with periodontitis within 15 min before and after scaling and root planing to monitor peptidase activity produced by Porphyromones gingivalis (Pg),Treponema denticola(Td) and Bacterides forsythus (Bf) in subgingival plaque. The peptidase activity was determined both spectrophotometrically and by using color standard.Results:The peptidase concentrations (Try U/L) before and after treatment were 0.44±0.23 and 0.34±0.26 (P<0.05),while Periocheck positiveness was found in 65/65 and 43/65 (P<0.01) of the patients,respectively.After treatment clinical parameters such as GI, PD,AL and peptidase concentration decreased (P<0.05) in 22 Periocheck positive patients,while those did not (P>0.05) in 43 negitive.Conclusion:Periocheck might provide a promising chair-side monitoring tool for the evaluation of scaling and root planing.

Objective: To evaluate the effects of expanded polytetrafluoroethylene (ePTFE) barrier membrane in guided periodontal tissue regeneration(GTR) . Methods:Nine patients with Ⅱ～Ⅲ furcation lesions were treated by guided tissue regeneration using ePTFE membrane. The membrane was retrieved 5 weeks after operation and examined by scanning electron microscopy (SEM) . Results:Large amount of lymphocytes were found on the external upper surfaces of ePTFE, with a little bacteria. The external lower surface of ePTFE was full of fibrocytes, red blood cells and lymphocytes.Conclusion:ePTFE membrane is biocompatible and can close the primary wound over a barrier which stops the downgrowth of junctional epithelium at the early stage of periodontal tissue repair after operation.

Rabbits were intoxicated with hypodermic injection of 0.8% CdCl2 in normal saline every other day for 3 months,and the blood level of urea nitrogen (BUN) and creatinine (Cr) and the activities of Na/K-ATpase,Ca-ATPase,and ?-GT in the renal cortex were determined.It was found that there were no remarkable changes of BUN and Cr level but significant reduction of the activities of the 3 enzymes.It is believed that the reduction of the enzyme activities is one of the factors to initiate the functional disturbances and morphological damages of the kidneys and plays an important role in the mechanism of renal failure if it is not promptly corrected.

Objective:To evaluate the immunogenicity of the recombinant plasmid pcDNA 3.1(+)/kgp_ cd.Methods:BALB/c mice were immunized with recombinant plasmid pcDNA 3.1(+)/kgp_ cd,KGP_ cd protein(control) or vector pcDNA 3.1(+)(control) by quadriceps injection or targeted submandibular gland(TSG) injection. Serum IgG and salivary sIgA levels were assayed by indirect ELISA after immunization. The expression of the protein KGP_ cd in quadriceps and submandibular gland was detected by immunohistochemistry techniques.Results: Serum specific anti-KGP_ cd IgG elicited by pcDNA 3.1(+)/kgp_ cd and KGP_ cd protein was significantly higher in both the quadriceps injection group and the TSG group than that in the pcDNA 3.1(+) group (P

Objective: To design and synthesize a novel vector for rhBMP2 delivery system in tissue engineering. Methods:Dextran glycidol methacrylate(dex-GMA) was synthesized with dextran(dex) and glycidol methacrylate(GMA).Dex-GMA microspheres were prepared by suspension polymerization. The swelling behavior of the microspheres was evaluated by the swelling equilibrium parameter Q. The biodegradation properties of the dextran-based hydrogel microspheres were assessed by the surface morphology before and after biodegradation. Results:Microspheres of dex-GMA in the size(diameter) of 20 to 80 ?m with good configuration were produced. Q value of the microspheres with the diameter of 20-30 ?m was 10.9?3.3,that of those with 70-80 ?m 8.9?6.4.Stirring speed, span-80(emulsifer) quantity and the proportion of dex-GMA affected the size of the microspheres. rhBMP2 was enveloped into the microspheres. Complete degradation of the microspheres was observed during 20 to 40 days at 37 ℃ in normal saline. Conclusion: Dex-GMA hydrogel microspheres may be a release controlling system for rhBMP2 delivery.

Objective:To investigate whether enamel matrix proteins (EMPs) has osteoinductive property. Methods: EMPs and propylene glycol alginate (PGA) in the size of 2 mm3 were placed into calf muscle of 8 SD rats on experiment side. PGA was placed on control side. The rats were sacrificed four weeks after operation. The calf samples were examined by histological observation.Result:Bone-like and/or cartilage-like tissues was not observed in all the operated calf muscles. Conclusion:EMPs are not osteoinductive.

Objective: To investigate the cause and mechanism of oral lichen planus (OLP). Methods: The expression of cyclins dependent kinases (CDK4) in epithelial cells in the samples in 40 cases of OLP and in 10 cases of healthy controls was observed by immunohistochemical method. Results: The expression indexes of CDK4 in the epithelial basal layer and spinous layer in OLP were 0. 5637 ? 0. 0201 and 0. 5388? 0. 0120, those in the healthy control were 0. 4020? 0. 0155 and 0. 3480? 0. 0163, respectively(p

Objective: To investigate the effects of insulin on the DNA synthesis and cell cycle distribution of human periodontal ligament cells (PDLs). Methods:PDLs were treated with insulin at the doses (U/L) of 0.01～1 000 for 72 h,DNA synthesis of the cells was measured by 3H-TdR incorporation and cell cycle distribution was studied by flow cytometer. Results : Insulin at 1 U/L to 1 000 U/L showed a significant concentration dependent stimulation of 3H thymidine uptake, and the effect of insulin at 100 ～ 1 000 U/L were not statistically different from that at 10 U/L. The percentage of PDL cells in G1 phase during exponential growth was decreased by insulin, while that in S phase and (G2+M) was increased in experimental group. Conclusion: Insulin increases DNA synthesis of PDL cells ,and stimulates the transformation of cells from G1 to S phase.

Objective: To evaluate the effects of guided tissue regeneration(GTR) in the treatment of degree Ⅱ-Ⅲ furcation defects with collagen membranes.Methods: 11 sites with Ⅱ-Ⅲ furcation defects were treated with collagen membranes(group of GTR); 10 sites received flap operation(group of FO). Clinical indexes, radiographs and gingival crevicular fluid(GCF) was collected before surgery and 3 months after treatment. Alkaline phosphatase(ALP) in GCF was measured. The data were analyzed statistically. Results: 3 months after surgery, the clinical parameters of PD, PFD and AL were decreased(P0.05). The decreace of the clinical parameters measured in group GTR was more than that in group FO(P