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Using a ligature-induced model in type-2 Zucker diabetic fatty (ZDF) rat and normoglycemic littermates, we investigated whether diabetes primarily affects periodontitis by enhancing bone loss or by limiting osseous repair. Diabetes increased the intensity and duration of the inflammatory infiltrate (P < 0.05). The formation of osteoclasts and percent eroded bone after 7 days of ligature placement was similar, while four days after removal of ligatures, the type 2 diabetic group had significantly higher osteoclast numbers and activity (P < 0.05). The amount of new bone formation following resorption was 2.4- to 2.9-fold higher in normoglycemic vs. diabetic rats (P < 0.05). Diabetes also increased apoptosis and decreased the number of bone-lining cells, osteoblasts, and periodontal ligament fibroblasts (P < 0.05). Thus, diabetes caused a more persistent inflammatory response, greater loss of attachment and more alveolar bone resorption, and impaired new bone formation. The latter may be affected by increased apoptosis of bone-lining and PDL cells.

Disturbances in GABAergic system have been observed in schizophrenics. In the present study, population association analysis was performed on 19 SNPs in the alpha(1), beta(2), gamma(2), epsilon and pi subunit genes of GABA(A) receptor. Five SNPs in GABRB2, namely B2I7G1584T, rs1816071, rs194072, rs252944 and rs187269, were found to be significantly associated, and their haplotypes in linkage disequilibrium, with schizophrenia. This represents the first report on any disease association of SNPs in the human GABA(A) receptor genes, and focuses attention on the GABAergic hypothesis of schizophrenia etiology.

The purpose of this study was to determine the effect of bisphosphonate on alveolar bone resorption in experimentally-induced peri-implantitis in beagle dogs. Experimental peri-implantitis was induced by ligation around the abutments, 6 months after placement of a fixture. Pamidronate (0.6 mg/kg) was injected intramuscularly every 3 days into each of 5 dogs. Another 5 dogs served as the control group and were injected with saline only. Peripheral blood and urine samples were collected every week up to 12 weeks after placement of the ligature. Standard X-rays were taken every week. Urinary deoxypyridinoline (DPD) and serum osteocalcin (OC) were evaluated by ELISA as markers of alveolar bone remodeling. X-ray films were analyzed with a computer image analyzer. After 12 weeks, the bone level was measured after removal of the gingival flap. The distance between the top surface of the fixture and the fundus of the defect was significantly lower in the Pamidronate group (1.59+/-0.55 mm, mean+/-SD) than in the control group (2.41+/-0.48 mm). Bone density analyzed from the X-ray films was significantly higher in the bisphosphonate group (69.2+/-8.7%, mean+/-SD) than in the control group (50.3+/-12.8%) after 2 to 8 weeks compared with the baseline value (100%). OC and DPD levels fluctuated during the experimental period. These findings suggest that bisphosphonate inhibits the progression of alveolar bone resorption during ligature-induced peri-implantitis in dogs.

Objective: To evaluate the chemotactic response of gingival fibroblasts and periodontal ligament cells to interleukin-8., Methods: The passage 6 cultured gingival fibroblasts and periodontal ligament cells (2.5 x 10(8) cell/L, respective) were placed in the upper compartment of the Transwell cell culture chamber. The lower compartment contained IL-8 with the concentrations of 10(-10), 10(-9), 10(-8), 10(-7) mol/L, respectively. Incubation was at 37 degrees C in an atmosphere of 95% air and 5% CO2 for 24 h. The number of migrated cells were counted under high power fields., Results: IL-8 at concentrations ranged from 10(-9)-10(-7) mol/L promoted the chemotactic movement of gingival fibroblasts in a dose-dependent manner. However, at the same IL-8 concentrations the chemotactic movement of periodontal ligament cells was not elevated., Conclusion: IL-8 may play its role in regulating chemotaxis of gingival fibroblast.

Objective: To evaluate gingival sulcus temperature in healthy subjects., Methods: Small size, high sensitivity and rapid response thermocouple was used to measure the gingival sulcus temperature in seven dental students with healthy periodontium. 28 teeth in each subject were tested., Results: For an individual subject, the gingival sulcus temperatures in all sites were always lower than sublingual temperature. There was obviously increased temperature gradient from anterior teeth to posterior teeth. The mean gingival sulcus temperatures on buccal sites were lower than that on lingual sites. There was no significant difference between maxillary and mandibular corresponding sites on lingual side. However, mandibular temperature was significantly lower than maxillary temperature on buccal side. Mandibular buccal temperature was the lowest in all tooth surfaces., Conclusion: Gingival sulcus temperature in subjects with healthy periodontium is easily influenced by environmental factors.