• Restorative Dentistry and Endodontics
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• v.43 no.2
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• pp.19.1-19.10
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• 2018

Objectives: This study investigated the effect of continuous application of 10-methacryloyloxydecyldihydrogen phosphate (MDP)-containing primer and luting resin cement on bond strength to tribochemical silica-coated yttria-stabilized tetragonal zirconia polycrystal (Y-TZP). Materials and Methods: Forty bovine teeth and Y-TZP specimens were prepared. The dentin specimens were embedded in molds, with one side of the dentin exposed for cementation with the zirconia specimen. The Y-TZP specimen was prepared in the form of a cylinder with a diameter of 3 mm and a height of 10 mm. The bonding surface of the Y-TZP specimen was sandblasted with silica-coated aluminium oxide particles. The forty tribochemical silica-coated Y-TZP specimens were cemented to the bovine dentin (4 groups; n = 10) with either an MDP-free primer or an MDP-containing primer and either an MDP-free resin cement or an MDP-containing resin cement. After a shear bond strength (SBS) test, the data were analyzed using 1-way analysis of variance and the Tukey test (${\alpha}=0.05$). Results: The group with MDP-free primer and resin cement showed significantly lower SBS values than the MDP-containing groups (p < 0.05). Among the MDP-containing groups, the group with MDP-containing primer and resin cement showed significantly higher SBS values than the other groups (p < 0.05). Conclusions: The combination of MDP-containing primer and luting cement following tribochemical silica coating to Y-TZP was the best choice among the alternatives tested in this study.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.399-404
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• 2000

The adjuvant effect of a muramyl dipeptide (MDP) derivative, MDP-Lys(L18), on enhancing of antitumor immunity induced by X-irradiated tumor cells against highly metastatic B16-BL6 melanoma cells was examined in mice. Mice immunized intradermally (i.d.) with a mixture of X-irradiated B16-BL6 cells and MDP-Lys (L18) [Vac+MDP-Lys (L18)] followed by an intravenous (i.v.)inoculation of $10^4$ viable tumor cells 7 days after immunization, showed a significant inhibition of experimental lung metastasis of B16-BL6 melanoma cells. The most effective immunization for the prophylactic inhibition of tumor metastasis was obtained from the mixture of $100{\;}\mu\textrm{g}$ of MDP-Lys (L18) and $10^4$ X-irradiatied tumor vaccine. Furthermore, immunization of mice with Vac+MDP-Lys(L18), 3 days after tumor challenge, resulted in a significant inhibition of lung metastasis of B16-BL6 melanoma cells in an experimental lung metastasis model. Similarly, the administration of Vac+MDP-Lys(L18), 1 or 7 days after tumor removal, markedly inhibited tumor metastasis of B16-BL6 in a spontaneous lung metastasis model. When Vac+MDP-Lys (L18) was i.d. administered 3 days after subcutaneous (s.c.) inoculation of tumor cells ($5{\times}10^5/site$) on the back, mice treated with Vac+MDP-Lys(L18) showed inhibition of significantly tumor growth on day 20. These results suggest that MDP-Lys (L18) is able to enhance antitumor activity induced by X-irradiated tumor vaccine to reduce lung metastasis of tumor cells, and is a potent immunomodulating agent which may be applied prophylactically as well as therapeutically to treatment of cancer metastasis.

• Korean Journal of Dental Materials
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• v.44 no.1
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• pp.61-68
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• 2017

This study evaluated the effects of various cleaning methods on the shear bond strength of zirconia ceramics after saliva contamination. Eighty zirconia disk specimens were divided into 8 groups. All groups were treated with one coat of MDP primer. All specimens (except the negative control) were contaminated with human saliva on the zirconia surface. The positive control went through the bonding procedure immediately after contamination without any cleaning procedure. With the exception of control groups, the remaining six groups were rinsed with water and either applied with MDP recoating (WATER+MDP) or without MDP recoating (WATER). While some were cleaned with a Ivoclean with MDP recoating (IVOCLEAN+MDP) or not applied with MDP recoating(IVOCLEAN), others were cleaned with a 1% NaOCl solution with MDP recoating (NaOCl+MDP) or without MDP recoating (NaOCl). The shear bond strength of all specimens were measured after being stored in distilled water at $37^{\circ}C$ for 24 hours. The data was analyzed statistically by an analysis of ANOVA, Tukey's post hoc test and Student's t-test was used to compare the shear bond strength according to the re-coating of MDP after the cleaning procedure. The positive control group showed the lowest shear bond strength value, and the WATER group and NaOCl group showed no significant difference when compared to the positive control group. The IVOCLEAN group showed significantly higher shear bond strength when compared to Water group and NaOCl group but not with the group of negative control. After rinsing with water or the NaOCl solution, the comparison of the single coating of MDP and re-coating of MDP showed different shear bond strengths but there was no significant difference to the negative control. After rinsing with Ivoclean, there was no significant difference to the negative control regardless of the recoating of MDP. In conclusion, the shear bond strength was affected by the cleansing procedure and Ivoclean was found to be effective regardless of the re-coating of MDP. When water or the NaOCl solution is used to remove surface contaminants, the re-coating of MDP provides a positive effect on cementation.

• Journal of dental hygiene science
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• v.23 no.4
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• pp.264-270
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• 2023

Background: Resin-based dental materials release residual monomers or other substances from incomplete polymerization into the oral cavity, thereby causing adverse biological effects on oral tissue. 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP), an acidic monomer containing dihydrogen phosphate and methacrylate groups, is the most commonly used component of resin-based dental materials, such as restorative composite resins, dentin adhesives, and resin cements. Although previous studies have reported the cytotoxicity and biocompatibility in various cultured cells, the effects of resin monomers on cellular aging have not been reported to date. Therefore, this study aimed to investigate the effects of the resin monomer 10-MDP on cellular senescence and inflamm-aging in vitro. Methods: After stimulation with 10-MDP, MC3T3-E1 osteoblast-like cells were examined for cell viability by WST-8 assay and reactive oxygen species (ROS) production by flow cytometry. The protein and mRNA levels of molecular markers of aging were determined by western blotting and RT-PCR analysis, respectively. Results: Treatment with 0.05 to 1 mM 10-MDP for 24 hours reduced the survival of MC3T3-E1 cells in a concentration-dependent manner. The intracellular ROS levels in the 10-MDP-treated experimental group were significantly higher than those in the control group. 10-MDP at a concentration of 0.1 mM increased p53, p16, and p21 protein levels. Additionally, an aging pattern was observed with blue staining due to intracellular senescence-associated beta-galactosidase activity. Treatment with 10-MDP increased the levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-8, however their expression was decreased by mitogen-activated-protein-kinase (MAPK) inhibitors. Conclusion: Taken together, these results suggest that the exposure of osteoblast-like cells to the dental resin monomer 10-MDP, increases the level of cellular senescence and the inflammatory response is mediated by the MAPK pathway.

• The Korean Journal of Physiology
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• v.30 no.1
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• pp.77-83
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• 1996

Platelet-activating factor(PAF) is a phospholipid mediator of pulmonary inflammation, and immunologic reaction. In this study, the role of PAF on tumor necrosis factor$(TNF_{-{\alpha}})$ production by rat alveolar macrophages(AM) was examined. When PAF $(10^{-12}{\sim}10{-16}\;M)$ alone was added to AM culture, $(TNF_{-{\alpha}})$ production was not significantly increased above the resting level. In contrast, the combined addition of PAF $(10^{-6}\;M)$ and muramyl dipeptide(MDP) $(1.0\;{\mu}g\ml)$ to AM cultures markedly enhanced $(TNF_{-{\alpha}})$ production with 8.2 fold increase compared with AM culture in resting state. This potentiative effect was 313% above the sum of the separate effects of PAF and MDP. To characterize MDP effects on $(TNF_{-{\alpha}})$ production, the dose-response of AM cultured with various concentrations of MDP was tested. High level of MDP $(10\;{\mu}g\ml)$ could not significantly enhance the potentiation effect on $(TNF_{-{\alpha}})$ production compared with AM cultures with low level of MDP $(0.1\;{\mu}g\ml)$, i.e. 112.5% vs 107.8%, respectively when $10^{-10}$ M of PAF was simultaneously added to the cell culture. These data support that the potentiation of TNF. g production in AM culture is mediated by PAF rather than MDf It was also evaluated whether the similar result was obtained in silica, respirable toxic particle-treated AM culture. $(TNF_{-{\alpha}})$ production was also significantly enhanced in the PAF $(10^{-6}\;M)$ and silica $(50\;{\mu}g\ml)$-added cell cultures with 4.7 fold above the value of silica alone-stimulated cells. These results indicate that PAF can potentiate $(TNF_{-{\alpha}})$ production by MDP-or silica- stimulated AM and suggest that PAF may play a potent role in lung inflammation and disease associated with microbe and occupational dust exposures.

• The Korean Journal of Nuclear Medicine
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• v.30 no.3
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• pp.361-366
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• 1996

This study was to determine the effect of $Al^{3+}$ in $^{99m}Tc$ eluate from $^{99}Mo-^{99m}Tc$ generator on labeling efficiency and biodistribution of $^{99m}Tc$-MDP. The chromatographic analysis of $^{99m}Tc$-MDP preparations containing $Al^{3+}(0-62.5{\mu}g/ml)$ showed decreased labeling efficiency $^{99m}Tc$ pertechnetate and hydrolyzed reduced $^{99m}Tc$ fraction increased with increasing concentrations of aluminum. However, the chromatography system could not discern between hydrolyzed reduced $^{99m}Tc$ and $^{99m}Tc$ labeled colloid. $^{99m}Tc$-MDP preparations containing aluminum were relatively stable. Chromatographic analysis also confirmed that no significant differences were observed in the radiochemical purity of the filtered and the unfiltered $^{99m}Tc$-MDP preparations containing aluminum by $0.22{\mu}m$ syringe filter. In biodistribution data of ICR-mice, blood and heart uptake were increasing with increasing concentrations of aluminum, because of decreasing labeling efficiency of $^{99m}Tc$-MDP and increasing of $^{99m}Tc$ pertechnetate. However, liver and bone uptake were not significantly increased. In rat images no difference were observed at $5{\mu}g/ml\;Al^{3+}$ compare with at $0{\mu}g/ml\;Al^{3+}$, but at $10{\mu}g/ml\;Al^{3+}$ lumbar uptake was increased. As a practical conclusion, a concentration below $10{\mu}g/ml\;Al^{3+}$($10{\mu}g/ml\;Al^{3+}$ is the maximum allowed in pertechnetate eluate from $^{99}Mo-^{99m}Tc$ generator by USP.) in $^{99m}Tc$-MDP radiopharmaceutical result in low labeling efficiency. Radiochemical purity 90% of $^{99m}Tc$-MDP is the minimum allowed by USP. Therefore, when soft tissue uptake is observed in $^{99m}Tc$-MDP bone scan and labeling efficiency is above 90%, we can expect that $Al^{3+}$ in pertechnetated eluate is not the cause of soft tissue uptake.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.25 no.4
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• pp.149-161
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• 2021

This study proposes a methodology for mission/path planning of an unmanned aerial vehicle (UAV) using an artificial potential field with the Markov Decision Process (MDP). The planning problem is formulated as an MDP. A low-resolution solution of the MDP is obtained and used to define an artificial potential field, which provides a continuous UAV mission plan. A numerical case study is conducted to demonstrate the validity of the proposed technique.

• The Korean Journal of Nuclear Medicine
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• v.34 no.3
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• pp.252-259
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• 2000

Purpose: The purpose of this study was to compare the radiation adaptive response (RAR) in peripheral lymphocytes (PL) of patients induced by Tc-99m MDP and Tc-99m DTPA scintigraphies. Materials and Methods: Lymphocytes from 45 patients (25 males, 20 females, mean age $44{\pm}18$ years) were collected before and after scintigraphies using 740 MBq Tc-99m MDP (n=22) or Tc-99m DTPA (n=23). Lymphocytes from 20 controls (12 males, 8 females, mean age $43{\pm}7$ years) were also collected. They were exposed to challenge dose of 2 Gy ${\gamma}-rays$ using a Cs-137 cell irradiator Number of ring-form (R) and dicentric (D) chromosomes was counted under the light microscope. From them a representative score, Ydr, was calculated as Ydr=(D+R)/cells. Adaptation index (AI) was defined as difference of Ydr between unconditioned and conditioned lymphocytes. Ydr was also measured after an administration of cycloheximide (CHM), a protein synthesis inhibitor, before challenge dose. Results: RAR was induced in both groups of patients. CHM abolished the adaptive response in both groups. AI of Tc-99m MDP group was significantly higher than that of Tc-99m BTPA group. Conclusion: Tc-99m MDP induced RAR was more prominent than those induced by Tc-99m DTPA.

• Journal of radiological science and technology
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• v.17 no.1
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• pp.77-86
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• 1994

The bone scan reflects the metabolic reaction of bone to a disease process, whether neoplastic, traumatic or inflammatory. In normal bone tissue, the labeled diphosphate complexes accumulate in the perivascular fluid next to the marrow cavity at the interface between uncalcified and calcified bone matrix. HMDP has the most rapid plasma clearance among the commonly used diphosphonate followed by MDP and then HEDP. I have studied about bone scan time by use of $^{99m}Tc-MDP$, and got 336 images from 112 patients. The result obtained as follow; 1. Accumulation rate of $^{99m}Tc-MDP$ is higher than other age groups in below 30-year old group. 2. Accumulation rate, in 10year old group, is 75.85% on 120min. but other groups are most high on 180 min. 3. The density differants between bone and soft tissue increased with time. 4. Image contrast is good in younger group than old.

• Journal of Information Technology Services
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• v.12 no.2
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• pp.361-371
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• 2013

Public domain defect data sets, such as NASA data sets which are available from the NASA MDP and PROMISE repositories, make it possible to compare the results of different defect prediction models by using the same data sets. This means that repeatable and general prediction models can be built. However, some recent studies have raised questions about the quality of two versions of NASA data set, and made new cleaned data sets by applying their data cleaning processes. We find that there are two ways in the NASA MDP versions to determine the defectiveness of a module, 0 or 1, and the two results are different in some cases. This serious problem, to our knowledge, has not been addressed in previous studies. To handle this ambiguity problem, we define two kinds of module defectiveness and two conditions that can be used to determine the ambiguous cases. We meticulously analyze 5 projects among the 13 NASA projects by using our ambiguity analysis method. The results show that JM1 and PC4 are the best projects with few ambiguous cases.