The Effects of various Regeneration techniques on Bone Regeneration around Dental Implant / 대한치주과학회지

The successful implantation necessitate tissue regeneration in site of future implant placement, there being severe bone defect. Therapeutic approaches to tissue regeneration in the site have used bone grafts, root surface treatments, barrier membranes, and growth factors, the same way being applied to periodontal tissue regeneration. Great interest in periodontal tissue regeneration has lead to research in bone graft, guided-tissue regeneration, and the administration of growth factors as possible means of regenerating lost periodontal tissue. The blood component separated by centrifuging the blood is the platelet-rich plasma. There are growth factors, PDGF, TGFbeta1, TGFbeta2 and IGF in the platelet-rich plasma. The purpose of this study was to study the histopathological correlation between the use of platelet-rich plasma and the healing of bone defect around implant fixture site. Implant fixtures were inserted and graft materials were placed into the left femur of in the experimental group, while the control group received only implant fixtures. In the first experimental group, platelet-rich plasma and BBP xenograft were placed at the implant fixture site, and the second experimental group had platelet-rich plasma, BBP xenograft, and the e-PTFE membrane placed at the fixture site. The degree of bone regeneration adjacent to the implant fixture was observed and compared histopathologically at 2, 4, and 8 weeks after implant fixture insertion. The results of the experiment were as follows: 1. Bone remodeling in acid etched surface near the implant fixture of all experimental groups was found to be greater than new bone formation. 2. Bone remodeling in acid etched surface distant to the implant fixture of all experimental groups was decreased and new bone formation was not changed. 3. Significant new bone formation in machined surface near the implant fixture of bothl experimental groups was observed in 2 weeks. 4. New bone formation in machined surface distant to the implant fixture of both experimental groups was observed. Bone remodeling was significant in near the implant fixture and not in distant to the implant fixture. The results of the experiment suggested that the change of bone formation around implant. Remodeling in machined surface distant to the implant fixture of both experimental groups, and new bone formation and remodeling near the implant fixture were significant.

Effect of Endothelin-1 on the Expression of Monocyte Chemoattractant Protein-1 in Cultured Human Proximal Tubular Epithelial Cells / 대한신장학회잡지

BACKGROUND: Monocyte chemoattractant protein- 1 (MCP-1) is produced by renal cells and an important mediator for monocyte/macrophage infiltration in various inflammatory renal diseases. In the process of renal disease, endothelin-1 is known to play an active role in cell growth, inflammation and fibrosis. The aim of this study was to investigate whether endothelin-1 regulates MCP-1 expression in cultured human proximal tubular epithelial cells. METHODS: Primary cultured human proximal tubular epithelial cells (PTEC) were incubated with or without various dose of endothelin-1. MCP-1 concentration in PTEC conditioned medium was measured by sandwich ELISA. MCP-1 mRNA expression was analyzed by Northern blotting. The NF-kB or AP-1 activity in response to endothelin-1 was measured by electrophoretic mobility shift assay. RESULTS: Endothelin-1 (10(-7) M) stimulated MCP- 1 production in PTEC, which was significant at 48 hours and various doses of endothelin-1 (10(-8)-10(-6) M) increased MCP-1 production from PTEC in a dose-dependent manner. Northern blot analysis revealed that endothelin-1 stimulated MCP-1 mRNA expression. Endothelin-1 (10(-7) M) stimulated both AP-1 binding activity and NF-kB binding activity up to 8 hour. Supershift analysis showed that p65 and p50 are major NF-kB subunit bound to the DNA probe and that c-Fos and c-Jun are major AP-1 subunit bound to the DNA probe. CONCLUSION: Our results suggest that endothelin- 1 may stimulate MCP-1 expression in proximal tubular epithelial cells through the activation of NF- kB and AP-1 binding activity.

Cytokine-Induced Expression of Vascular Endothelial Growth Factor in Peritoneal Mesothelial Cells / 대한신장학회잡지

BACKGROUND: The mechanism of increased peritoneal permeability during peritonitis has not been clearly determined. We studied the changes in vascular endothelial growth factor (VEGF) levels in dialysate effluents during CAPD peritonitis, and VEGF expression in cultured peritoneal mesothelial cells (MCs) stimulated with IL-1 alpha, TNF alpha, and IFN gamma. METHODS: In 30 CAPD patients with peritonitis, dialysate effluents were serially collected at the time of diagnosis of peritonitis and when the peritonitis was recovered. Primarily cultured MCs were incubated with IL-1alpha or TNFalpha alone or in combination with INF gamma. VEGF level in dialysate effluent and MCs conditioned medium was measured by sandwich ELISA. VEGF mRNA expression was analyzed by Northern blotting. The activation of NFkappaB in response to IL-1alpha or TNFalpha was measured by electrophoretic mobility shift assay (EMSA). RESULTS: VEGF levels in dialysate effluent at the time of diagnosis of peritonitis were significantly higher (456+/-45 pg/mL) than those when the peritonitis was recovered (245+/-21 pg/mL)(p<0.00001). Both IL-1 alpha and TNFalpha stimulated VEGF production in MCs, and the stimulation was significant from 24 hours to 72 hours. INFgamma, in combination with IL-1 alpha or TNF alpha, significantly amplified IL-1 alpha - or TNF alpha - induced VEGF production. Pre-incubation of MCs with NF kappa B inhibitor, pyrrolidine dithiocarbamate, totally blocked IL-1 alpha - or TNF alpha-induced VEGF production. Northern blot analysis revealed that IL-1 alpha and TNF alpha stimulated VEGF mRNA expression in a dose dependent manner. The stimulation was peak at 4 hours. IL-1alpha and TNF alpha stimulated NFkappa B binding activity in MCs as early as at 15 minutes, with a peak activity at 1 hour, and p65 subunit was supershifted. CONCLUSION: Our results suggest that increased expression of VEGF in peritoneal mesothelial cells stimulated with proinflammatory cytokines, IL-1alpha, TNFalpha, and IFN gamma, plays a role in the increased peritoneal permeability during CAPD peritonitis.

Malignant lymphomas of the nasal cavity and Waldeyer's Ring: clinicopathologic and immunohistochemical study

The clinicopathologic and immunohistochemical finding of 10 cases of nasal non-Hodgkin's lymphoma (NHL) and 23 cases of Waldeyer's ring NHL were studied. Immunohistochemically, nasal NHL expressed T-cell markers exclusively, whereas the NHL of Waldeyer's ring were of both T-cell (56.5%) and B-cell lineages (43.5%). Angioinvasiveness by tumor cells was exclusively noted in the T-lineage lymphomas. Epithelial hyperplasia, epitheliotropism by tumor cells, and extensive invasion of adjacent normal tissue were more prominent in T-cell lymphomas than in B-cell lymphomas. T-lineage lymphomas showed distant extranodal spread pattern involving the skin, soft tissue, stomach, spleen, and the liver, whereas B-lineage lymphomas tended to localize in the lymph nodes. The survival rate of Nasal NHL was similar to that of Waldeyer's ring NHL. Although not statistically significant because of small sample numbers, immunophenotype, histologic groups of monomorphic lymphoma, and stage had prognostic importance. In general, T-lineage lymphomas presented with a higher stage than B-lineage lymphomas (p < 0.05)-and overall survival was poor. Stage I disease showed a much more favorable prognosis than stage II disease. Monomorphic lymphomas had a shorter survival than polymorphic reticulosis (PR) or lymphomas with features of PR. This result in conjunction with the morphologic transition between them suggested that monomorphic lymphoma may represent the most advanced stage in the spectrum of PR, lymphoma with features of PR, and monomorphic lymphoma.