No abstract available.
Korea ; Spinal Cord Injuries*

The fracture of acrylic resin dentures remains an unsolved problem. Therefore, many investigations have been performed and various approaches to strengthening acrylic resin, for example, the reinforcement of heat-cured PMMA resin using glass fibers, have been suggested over the years. The aim of the present study was to investigate the effect of short glass fibers treated with silane coupling agent on the transverse strength of heat-polymerized PMMA denture base resin. To avoid fiber bunching and achieve even fiber distribution, glass fiber bundles were mixed with PMMA powder in conventional mixer whose blade was modified to be blunt. Composite of glass fiber (11micrometer diameter, 3mm & 6mm length, silane treated) and PMMA resin was made. Transverse strength and Young's modulus were estimated. Glass fibers were incorporated with 1%, 3%, 6% and 9% by weight. Plasticity and workability of dough was evaluated. Fracture surface of specimens was investigated by SEM. The results of this study were as follows 1. 6% and 9% incorporation of 3mm glass fibers in the PMMA resin enhanced the transverse strength of the test specimens (p<0.05). 2. 6% incorporation of 6mm glass fibers in the PMMA resin increased transverse strength, but 9% incorporation of it decreased transverse strength (p<0.05). 3. When more than 3% of 3mm glass fibers and more than 6% of 6mm glass fibers were incorporated. Young's modulus increased significantly (p<0.05). 4. Workability decreased gradually as the percentage of the fibers increased. 5. Workability decreased gradually as the length of the fibers increased. 6. In SEM and LM, there was no bunching of fibers and no shortening of fibers.
Denture Bases ; Dentures ; Elastic Modulus ; Glass* ; Plastics ; Polymethyl Methacrylate*

No abstract available.
Animals ; Embryonic Development* ; Embryonic Structures* ; Female ; Mice* ; Pregnancy

No abstract available.
Dendritic Cells*

PURPOSE: To determine the necessity of site-specific bone mineral density(BMD) measurement and the difference between the BMD of the two femora using DXA in the evaluation of osteoporosis. MATERIALS & METHODS: Total BMD and regional BMD(Lumbar spine, femoral neck, Ward's area, intertrochanter area) were measured on seventy-eight healthy persons without previons diseases, and the statistical significance analyzed. RESULTS: Total BMD did not reliably reflect the site-specific BMD. There was a high correlation between BMD in opposing femora. Correlation coefficients between the femoral neck, Ward's area, trochanter area were 0. 939, 0.874 and 0.916 respectively. CONCLUSION: We conclude that a measuremnt of site-specific BMD is necessory because the total BMD can not reliably predict the regional BMD. The measurement of BMD in one femur can predict the BMD of the contralateral femur. If there is no history of femoral neck disease, unilateral BMD measurement is recommended for femoral evaluation.
Absorptiometry, Photon* ; Femur ; Femur Neck ; Humans ; Osteoporosis ; Spine

To characterize the immunopathologic phenotype of the cells in the lesional ti.:sue and to further examine the mechanism of the development of the annular lesions in leprosy, we have studied immune cells (T lymphocyte and its subsets, Langerhans cells, and HLA-DR antigen expressing cells) at different anatomical sites inside, active border, and outside normal skin in the annular lesions of leprosy. We took biopsy specimens from 4 patients of BT type, then processed the specimens by the staining methods eif indirect immunoperoxidase with monoclonal antibodies. In the active border the number of T cell was over 50g of the total cells infiltrated in the dermis. Helper T cells were dominant in number, and about three fourths of the cells were positive for HLA-DR staining. In two patients they had expression of DR antigen on the surfaces of the keratinocytes in the epidermis, in contrast to that of the inside, even the intensities were not. strong. At the inside of the annular lesions T cells were about 40% and the ratio of helper/suppressor T cell was approxiinately 1: 1, However, HLA-DR positive immune cells were not more than 10g among the total infiltrates. Langerha,ns cells were increased in number and in size either in the border or at the inside of the annular lesions. With these results we presume that the T cell mediated imrnune responses against Mycobacterium leprae may play an important role in the formation and extension of the annular lesions in leprosy.
Antibodies, Monoclonal ; Biopsy ; Dermis ; Epidermis ; HLA-DR Antigens ; Humans ; Keratinocytes ; Langerhans Cells ; Leprosy* ; Lymphocytes ; Mycobacterium leprae ; Phenotype ; Skin ; T-Lymphocytes ; T-Lymphocytes, Helper-Inducer

No abstract available.
Carcinoma, Renal Cell*

Dendritic cells (DCs) are the most potent antigen presenting cells that can activate naive T cells. Mature DCs exress high levels of MHC and costimulatory molecules on their surface and have capacity to produce IL-12, a 75 kDa heterodimeric cytokine composed of p35 and p40 subunit. IL-12 is currently thought to be one of most critical determinants for skewing the immune response towards Th1. Expression of IL-12 in dendritic cells seems to be regulated by various stimuli including CD40L. In the present study we investigated expression of IL-12 in mature DCs, which were cultured from bone marrow cells in the presence of GM-CSF. Maturity of the DCs was confirmed by morphologic characteristics, immunophenotypes, and allostimulatory activities. Exprssion levels of IL-12 p40 in the DCs were measured by semi-quantitative RT-PCR. Increases in IL-12 p40 expression were observed after treatment with lipopolysaccharide (LPS), an anti-MHC class II monoclonal antibody, or an anti-CD40 monoclonal antibody. The most remarkable increases, however, were observed in the DCs treated with an anti-CD40 monoclonal antibody. These results support a previous notion that signals through CD40/CD40L interaction may be important for the production of IL-12 by DCs. Moreover, results of this study show a possibility of using monoclonal antibodies against CD40 molecules for preparing DCs producing high amount of IL-12, which can be used for anti-tumor or anti-viral immunotherapy.
Animals ; Antibodies, Monoclonal ; Antigen-Presenting Cells ; Bone Marrow Cells ; CD40 Ligand ; Dendritic Cells* ; Granulocyte-Macrophage Colony-Stimulating Factor ; Immunotherapy ; Interleukin-12* ; Mice* ; T-Lymphocytes

STATEMENT OF PROBLEM: The success of implants depends on intimate and direct contact of implant material on bone tissue and on functional relationship with soft tissue contact. Creation and maintenance of osseointegration depend on the understanding of the tissue's healing, repairing, and remodeling capacity and these capacities rely on cellular behavior. Altering the surface properties can modify cellular responses such as cell adhesion, cell motility, bone deposition. Therefore, various implant surface treatment methods are being developed for the improved bone cell responses. PURPOSE: The purpose of this study was to evaluate the responses of osteoblast-like cells to surface- modified titanium. MATERIALS AND METHODS: The experiment was composed of four groups. Group 1 represented the electropolished surface. Group 2 surfaces were machined surface. Group 3 and Group 4 were anodized surfaces. Group 3 had low roughness and Group 4 had high roughness. Physicochemical properties and microstructures of the d iscs were examined and the responses of osteoblast-like cells to the discs were investigated. The microtopography was observed by SEM. The roughness was measured by three-dimension roughness measuring system. The microstructure was analyzed by XRD, AES. To evaluate cell responses to modified titanium surfaces, osteoblasts isolated from calvaria of neonatal rat were cultured. Cell count, morphology, total protein measurement and alkaline phosphatase activities of the cultures were examined. RESULTS AND CONCLUSION: The results were as follows 1. The four groups showed specific microtopography respectively. Anodized group showed grain structure with micropores. 2. Surface roughness values were, from the lowest to the highest, electropolished group, machined group, low roughness anodized group, and high roughness anodized group. 3. Highly roughened anodized group was found to have increased surface oxide thickness and surface crystallinity. 4. The morphology of cells, flattened or spherical, were different from ach other. In the electropolished group and machined group, the cells were almost flattened. In two anodized groups, some cells were spherical and other cells were flattened. And the 14 day culture cells of all of the groups were nearly flattened due to confluency. 5. The number of attached cells was highest in low roughness anodized group. And the machined group had significantly lower cell count than any other groups(P<.05). 6. Total protein contents showed no difference among groups. 7. The level of alkaline phosphatase activities was higher in the anodized groups than electropolished and machined groups(P<.05).
Alkaline Phosphatase ; Animals ; Bone and Bones ; Cell Adhesion ; Cell Count ; Cell Movement ; Edible Grain ; Crystallins ; Osseointegration ; Osteoblasts ; Rats ; Skull ; Surface Properties ; Titanium*

Effects of Ultratiolet (UV) light was studied in isolated thoracic aortae of rabbits and porcine coronary arteries. The following results were obtained. 1) Radiation of UV light did not affect both arterial rings in resting tension. 2) Both arterial preparations contracted with various vasoconstrictors (KCI,NE,PE,BayK 8644 and (+S202 etc.) were relaxed by UV light radiation in a radiation time-dependent fashion. 3) The magnitudes of the relaxation were not significantly different in both the rings with or without intact endothelium. 4) MB and LY markedldy reduced the UV light-induced relaxation in both the rings. 5) PP significantly attenuated the UV light-induced relaxation of rabbit thoracic aorta, but did not affect that of porcine coronary artery. 6) The UV Light-induced relaxation of porcine coronary artery was significantly attenuated by DT or NF, while that of rabbit thoracic aorta was not. 7) (+)S202 significantly potentiated the UV light-induced relaxation of porcine coronary artery contracted with KCI or Hist. Above results suggest that the UV light-induced relaxation of vascular smooth muscles is independent on the endothelium, and the relaxation results from primarily activation of guanylyl cyclase and is in part related to adenylyl cyclase and calcium metabolism. In adddition, a dihydropyridine calcium agonist, (+)S202, may sensitize vascular smooth muscle to the relaxing effect of UV light through some unknown mechanism.
Adenylyl Cyclases ; Aorta, Thoracic ; Calcium* ; Coronary Vessels ; Endothelium ; Guanylate Cyclase ; Metabolism ; Muscle, Smooth* ; Muscle, Smooth, Vascular ; Rabbits ; Relaxation* ; Ultraviolet Rays ; Vasoconstrictor Agents