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1.
Dent Mater J ; 37(5): 740-745, 2018 Sep 30.
Article in English | MEDLINE | ID: mdl-29848854

ABSTRACT

Infection control of dental stone cast is an important issue. Ozone is effective for disinfection against microorganisms and inactivation of viruses. However, there is little information regarding the use of ozone. We prepared 4 types of gypsum specimens and 3 types of disinfectants (4-5 ppm Ozonated water [OZW], 2% glutaraldehyde [GL], and 1% sodium hypochlorite [SH]). Gypsum specimens were immersed in each disinfectant for 5 and 10 min, and surface roughness was then examined using laser scanning microscopy. Surface microstructure was investigated using scanning electron microscopy. Immersion of gypsum specimens in SH, GL, and OZW increased the surface roughness to a maximum of 1.04, 0.37, and 0.30 µm, respectively, based on the difference between the average values of surface roughness before and after the disinfection procedure. The effects of OZW and GL were comparable. OZW is useful as a candidate for relatively safe disinfection of material for dental stone casts.


Subject(s)
Calcium Sulfate/chemistry , Dental Casting Investment/chemistry , Dental Disinfectants/chemistry , Dental Impression Materials/chemistry , Ozone/chemistry , Water/chemistry , Glutaral/chemistry , Materials Testing , Microscopy, Electron, Scanning , Sodium Hypochlorite/chemistry , Surface Properties
2.
Rev Sci Instrum ; 87(2): 02B137, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26932019

ABSTRACT

To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of ∼16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles.

3.
ACS Appl Mater Interfaces ; 7(30): 16828-36, 2015 Aug 05.
Article in English | MEDLINE | ID: mdl-26172315

ABSTRACT

Quality control of mesenchymal stem cells is an important step before their clinical use in regenerative therapy. Among various characteristics of mesenchymal stem cells, reproducibility of population compositions should be analyzed according to characteristics, such as stem cell contents and differentiation stages. Such characterization may be possible by assessing the expression of several surface markers. Here we report our attempts to utilize antibody arrays for analyzing surface markers expressed in mesenchymal stem cell populations in a high-throughput manner. Antibody arrays were fabricated using a glass plate on which a micropatterned alkanethiol monolayer was formed. Various antibodies against surface markers including CD11b, CD31, CD44, CD45, CD51, CD73, CD90, CD105, and CD254 were covalently immobilized on the micropatterned surface in an array format to obtain an antibody array. To examine the feasibility of the array, cell binding assays were performed on the array using a mouse mesenchymal stem cell line. Our results showed that cell binding was observed on the arrayed spots with immobilized antibodies which exhibited reactivity to the cells in flow cytometry. It was further found that the density of cells attached to antibody spots was correlated to the mean fluorescent channel recorded in flow cytometry. These results demonstrate that data obtained by cell binding assays on the antibody array are comparable to those by the conventional flow cytometry, while throughput of the analysis is much higher with the antibody array-based method than flow cytometry. Accordingly, we concluded that the antibody array provides a high-throughput analytical method useful for the quality control of mesenchymal stem cells.


Subject(s)
Antibodies/immunology , Cytokines/immunology , Immunoassay/instrumentation , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/immunology , Tissue Array Analysis/instrumentation , Animals , Antibodies/chemistry , Batch Cell Culture Techniques/instrumentation , Cell Line , Equipment Design , Equipment Failure Analysis , Mice
4.
Health Phys ; 101(3): 259-64, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21799342

ABSTRACT

To examine the effects of carbon ion and gamma ray irradiation on cancer-induced osteoclastogenesis, mouse calvaria MC3T3-E1 cells were cultured with conditioned medium from irradiated and non-irradiated MCF7 human breast cancer cells. The authors examined RANKL and OPG mRNA expression in osteoblastic MC3T3-E1 cells following treatment with conditioned MCF7 medium. Co-cultured MC3T3-E1 and bone marrow cells treated with conditioned medium from irradiated MCF7 cells showed decreased numbers of osteoclasts, assessed using TRAP staining. Conditioned medium from control MCF7 cells elevated the RANKL/OPG mRNA ratio in MC3T3-E1 cells; this effect was suppressed by carbon ion irradiation of the MCF7 cells. These data demonstrate that indirect interactions between breast cancer cells and MC3T3-E1 cells induce osteoclastogenesis in vitro through modulation of RANKL expression and that this process is suppressed by carbon ion irradiation.


Subject(s)
Bony Callus/radiation effects , Breast Neoplasms/pathology , Carbon/therapeutic use , Gamma Rays/therapeutic use , Osteogenesis/radiation effects , 3T3 Cells , Animals , Bone Neoplasms/etiology , Bone Neoplasms/metabolism , Bone Neoplasms/pathology , Breast Neoplasms/metabolism , Female , Gene Expression Regulation/radiation effects , Heavy Ion Radiotherapy , Humans , Mice , RNA, Messenger/metabolism , RNA, Messenger/radiation effects , Receptor Activator of Nuclear Factor-kappa B/metabolism , Receptor Activator of Nuclear Factor-kappa B/radiation effects
5.
Dent Mater J ; 29(1): 75-83, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20379016

ABSTRACT

We evaluated the effects of high-dose major components in oral disinfectants on oral cells from the standpoints of the cell cycle and apoptosis. We examined the viability and cell cycle of human gingival fibroblasts (HGFs) treated with the components of dental disinfectants, benzethonium chloride (BEC), benzalkonium chloride (BAC), and povidone iodine (PVD-I) using a cell counting kit and flow cytometry. The IC(50) inhibitory concentration value in HGF cultures at 24 hours was 1.3x10(-2) mM BEC, 6.0x10(-3) mM BAC, and 2.6x10(-1) mM PVD-I. In the cell cycle analysis, propidium iodide-stained HGFs were arrested in G(0)/G(1) of the cell cycle by all three disinfectants, and in the apoptosis assay, annexin V-FITC/PI-stained HGFs that became apoptotic at 5.0x10(-2) and 1.0x10(-1) mM BEC and 5.0x10(-2) and 1.0x10(-1) mM BAC, but not in PVD-I at concentrations as high as 5.0x10(-1) mM. Our findings describe the effects of high-dose oral disinfectants, rather than clinical concentrations. Nevertheless, appreciating the effects of high-dose disinfectants absorbed into the human body is important, where they may accumulate in specific tissues and cells.


Subject(s)
Apoptosis , Cell Cycle/drug effects , Dental Disinfectants/toxicity , Gingiva/drug effects , Analysis of Variance , Benzalkonium Compounds/toxicity , Benzethonium/toxicity , Cells, Cultured , Chi-Square Distribution , Dose-Response Relationship, Drug , Fibroblasts/drug effects , Flow Cytometry , Gingiva/cytology , Humans , Inhibitory Concentration 50 , Povidone-Iodine/toxicity
6.
J Dent ; 36(12): 993-8, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18819741

ABSTRACT

OBJECTIVES: The effects of chlorine dioxide (ClO2), sodium hypochlorite (NaOCl), and hydrogen peroxide (H2O2) on cell death and the cell cycle of human gingival fibroblast (HGF) cells were examined. METHODS: The inhibition of HGF cell growth was evaluated using a Cell Counting Kit-8. The cell cycle was assessed with propidium iodide-stained cells (distribution of cells in G0/G1, S, and G2/M phases) using flow cytometry. The patterns of cell death (necrosis and apoptosis) were analyzed using flow cytometry with annexin V-FITC/PI staining. RESULTS: The lethal doses for 50% of the cells (LD50) of ClO2, NaOCl, and H2O2 were 0.16, 0.79, and 0.11 mM, respectively. All three dental disinfectants induced G0/G1 cell cycle arrest. H2O2 induced apoptosis at concentrations of 0.05 and 0.1 mM, while NaOCl and ClO2 did not induce significant apoptosis at any concentration examined. CONCLUSIONS: These results suggest that ClO2 is sufficient for use as a dental disinfectant compared with H2O2 or NaOCl.


Subject(s)
Chlorine Compounds/toxicity , Fibroblasts/drug effects , Gingiva/drug effects , Oxides/toxicity , Root Canal Irrigants/toxicity , Apoptosis/drug effects , Cell Count , Cell Cycle/drug effects , Cell Death/drug effects , Cell Division/drug effects , Cells, Cultured , G1 Phase/drug effects , G2 Phase/drug effects , Gingiva/cytology , Humans , Hydrogen Peroxide/toxicity , Lethal Dose 50 , Materials Testing , Necrosis , Oxidants/toxicity , Resting Phase, Cell Cycle/drug effects , S Phase/drug effects , Sodium Hypochlorite/toxicity
7.
Bull Exp Biol Med ; 142(5): 618-24, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17415477

ABSTRACT

We investigated the effects of carbon ion and gamma-irradiation on osteoblastic MC3T3-E1 cells by comparing mRNA expression levels for RANKL and osteoprotegerin by RT-PCR. MC3T3-E1 cells were irradiated with 2, 4, or 6 Gy of carbon ions or gamma-rays, and total RNA was harvested 1, 2, 3, 5, or 7 days after irradiation. The RANKL mRNA/OPG mRNA ratio in carbon ion-irradiated MC3T3-E1 cells was lower, while in gamma-irradiated MC3T3-E1 cells this ratio was higher than in non-irradiated cells. To evaluate osteoclastogenesis of MC3T3-E1 cells, carbon ion- or gamma-irradiated cells were co-cultured with non-irradiated cells from murine bone marrow. Staining for tartrate-resistant acid phosphatase (TRAP) in co-cultures showed that carbon ion irradiation suppressed osteoclastogenesis. This result is consistent with the lower RANKL/OPG mRNA ratio for carbon ion-irradiated cells. These results suggest that carbon ion irradiation acts primarily on osteoblastic cells, leading to a decrease in the RANKL/OPG mRNA ratio. This effect, in turn, leads to a decrease in osteoclastogenesis and osteoclast activity, which results in an increase in bone volume.


Subject(s)
Carbon Radioisotopes , Gamma Rays , Gene Expression/radiation effects , Osteoblasts/metabolism , Osteoblasts/radiation effects , Osteoprotegerin/biosynthesis , RANK Ligand/biosynthesis , Acid Phosphatase/biosynthesis , Animals , Bone Marrow Cells/metabolism , Cell Line , Coculture Techniques , Isoenzymes/biosynthesis , Mice , NF-kappa B/metabolism , Tartrate-Resistant Acid Phosphatase
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