Expression of ssrA in non-pathogen-induced adaptation in the oral cavity through signal exchange with oral pathogens

INTRODUCTION: This study was conducted to evaluate ssrA expression resulting from adaptation of Escherichia coli (E. coli) to oral pathogens through signal exchange. MATERIALS AND METHODS: Human cell lines Hep2 and HT29, wild-type E. coli (WT K-12), ssrA knock-out E. coli (Delta K-12), and Scleropages aureus (S. aureus) were used. A single culture consisting of Hep2, HT29, WT K-12, and Delta K-12, and mixed cultures consisting of Hep2 and WT K-12, Hep2 and Delta K-12, WT K-12 and S. aureus , Delta K-12 and S. aureus , and Hep2, WT K-12, and S. aureus were prepared. For HT29, a mixed culture was prepared with WT K-12 and with WT K-12 and S. aureus. Total RNA was extracted from each culture with the resulting expression of ssrA, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB), and p53 was evaluated by Reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The expression of ssrA in a single culture of WT K-12 was lower than that observed in the mixed culture of WT K-12 with S. aureus. Greater ssrA expression was observed in the mixed culture of WT K-12 with Hep2 than in the single culture of WT K-12. The expression of NF-kappaB was higher in the mixed culture of Hep2 with Delta K-12 than that in the mixed culture of Hep2 with WT K-12, and was lowest in the single culture of Hep2. The expression of ssrA was higher in the mixed culture of WT K-12 with Hep2 and S. aureus than in the mixed culture of WT K-12 with Hep2. CONCLUSION: These results suggest that ssrA plays an important role in the mechanism of E. coli adaptation to a new environment.

Changes of Pharyngeal Airway Space after Mandibular Setback Surgery in Computed Tomography Images

Evaluation of bone formation by recombinant human BMP-2 and rapid prototype titanium cap in rabbit calvaria using micro computed tomography

INTRODUCTION: This study examined the effect of recombinant human bone morphogenetic protein (rhBMP)-2 and beta-tricalcium phosphate (beta-TCP) on new bone formation in a rabbit calvarium using a rapid prototype titanium cap (RP Ti cap). MATERIALS AND METHODS: Eight New Zealand white rabbits were used in this study. Hemispherical RP Ti caps (10 mm in diameter) were implanted subperiosteally on the rabbit calvaria. beta-TCP was filled in the RP Ti cap in the control group, and rhBMP-2 soaked beta-TCP was used in experimental group. The rabbits were sacrificed 2 and 4 weeks after the operation. The volume and pattern of newly formed bone was analyzed by micro computed tomography (CT). RESULTS: Macroscopically, there were no abnormal findings in any of the animals. The micro CT images revealed new bone from the calvaria that expanded gradually toward the top of the titanium cap, particularly along the inner surface of the titanium cap in the experimental group at 4 weeks after grafting. There was no significant difference in new bone volume ratio between the control and experimental groups at 2 weeks after grafting. There was a statistically significant difference in the new bone volume ratio between the experimental (14.1+/-1.8 %) and control (7.2+/-1.5 %) groups at 4 weeks after grafting (P<0.01). CONCLUSION: The RP Ti cap can effectively guide new bone formation and rhBMP-2 can induce the new bone formation.

The immunosuppression effect of cyclosporine A on the allogenic calvarial bone graft in mice

INTRODUCTION: This study examined the effect of cyclosporine A (CsA) on the allogenic cranial bone graft in the mice. MATERIALS AND METHODS: Twenty eight 12-week-old male ICR mice weighing 40 g were used. The experimental group was injected subcutaneously with CsA (10 mg/kg/day) diluted in Caster oil for 7 days prior to the graft until sacrifice. The control group was injected with the same solution without CsA. RESULTS: In the experimental group, fibrous connective tissues and small amounts of inflammatory cells were observed. At 2 weeks after the allograft in the experimental group, new bone formation in fibrous collagenous tissue and around the allogenic bone was noted. At 4 weeks after the allograft, new bone formation was active along and at the periphery of the mature allogenic bone. The proliferation of blood vessels increased in bone marrow. In the control group, fibrous tissues and inflammatory cells were observed around the allogenic bone and existing bone at 1 week. At 2 weeks after the allograft, the proliferation of blood vessels accompanied by inflammatory cells were scattered in the fibrous connective tissues. New bone formation around the allogenic and existing bone could be observed. At 4 weeks after the allograft, inflammatory cells were severely infiltrated around the allogenic bone. Osteoclasts were scattered along the allogenic bone and induced bone resorption. CONCLUSION: These results suggest that the daily administration of CsA (10 mg/kg/day) induces efficient immunosuppression without serious complications ,and this protocol might be useful for the experimental model of allogenic bone grafts.

Expression of osteoclastogenesis related factors in dental implant patients

INTRODUCTION: Bone resorption is a unique function of osteoclasts. Osteoclasts are a specialized macrophage polykaryon whose differentiation is regulated principally by macrophage colony-stimulating factors, receptor activator of nuclear factor kappaB ligand (RANK) ligand, osteoprotegerin (OPG), and interleukins (IL). Reflecting the integrin-mediated signals, osteoclasts develop a specialized cytoskeleton that allows it to establish an isolated micro-environment between itself and the bone, wherein matrix degradation occurs by a process involving proton transport. The levels of IL-1, IL-6, OPG, and prostaglandin E2 (PGE2) expression were evaluated to study the correlations between dental implant teeth and the adjacent teeth. MATERIALS AND METHODS: The exudate of the gingival crevice acquired from dental implants, adjacent teeth, opposite teeth and contralateral teeth of 24 patients. RESULTS: 1. The levels of IL-1, IL-6, OPG and PGE2 expression in dental implant teeth were higher than those of the contralateral teeth. 2. IL-1 revealed a higher expression level in the adjacent teeth than in dental implant teeth. 3. The dental implant teeth and adjacent teeth did not show a remarkable difference in the level of IL-1 expression. 4. All the other cytokines were strongly expressed in the dental implant compared to the adjacent teeth. CONCLUSION: These results suggest that there might be close correlation between dental implant teeth and adjacent teeth in terms of the expressions of cytokines that affect the development and regulation of osteoclasts.

The Effect of New Bone Formation of Onlay Bone Graft Using Various Graft Materials with a Titanium Cap on the Rabbit Calvarium

0.05).SUMMARY: This result suggests that autogenous bone is the best choice for new bone formation, but when autogenous bone graft is in limited availability, alloplastic and xenogenic bone graft also can be an alternative bone graft material to use with a suitably guided membrane.