Radio Frequency Identification Gate System to Identify Misused Personal Dosimeters.

The use of two personal dosimeters, one worn over and one worn under a protective apron, provides the best estimate of effective dose. However, inappropriate positioning of dosimeters is a common occurrence, resulting in abnormally high or low radiation exposure records. Although such incorrect positioning can be identified by radiation exposure records, doing so is time-consuming and labor-intensive for administrators. Therefore, a system that can identify incorrect locations of dosimeters without burdening administrators must be developed. In this study, we developed a radio frequency identification (RFID) gate system that can differentiate between two RFID-tagged dosimeters placed over and under a metal apron and identify misused dosimeters. To simulate the position of the RFID-tagged dosimeters, we designed four dosimeter-wearing classes, including "proper use" and three types of "misuse" (i.e., "reversed," "both under," and "both over"). When the system predicts "misuse" based on the tag reading, the worker is alerted with lights and alarms. The system performance was evaluated using a confusion matrix, with an overall accuracy of 97.75%, demonstrating high classification performance. The safety of the system against life support devices was also investigated, demonstrating that they were not affected by the electric field at 0.3 m or more from the antenna of the system under any transmit powers tested. This RFID gate system is highly capable of identifying incorrectly positioned dosimeters, enabling real-time monitoring of dosimeters to manage their positioning.

Use of an educational video with mobile technology for the informed consent process: A randomised controlled trial on patients undergoing surgery for an impacted lower third molar.

The purpose of this study was to determine whether audiovisual presentation of consent information would significantly improve patients' postoperative recall of risks and complications regarding surgical removal of impacted lower third molars compared to the presentation of traditional written consent information. A randomised controlled study on 59 patients undergoing third molar removal was conducted. Patients in the intervention group (n = 30) viewed an educational video on risks and complications related to surgery using mobile tablets. Control-group patients (n = 29) received written information of the risks and complications. Patients' postoperative recall of potential risks for dysesthesia of the lower lip and tongue, infection, and bleeding along with surgical complications of facial oedema, trismus, and pain were assessed using true-false tests. The effect of audiovisual information on postoperative recall of the risks and complications was determined by comparing accuracy scores between the intervention group and control group using the independent t-test. The intervention group was found to have significantly better recall scores of the potential risks and complications, due to much higher accuracy in their recall of bleeding and dysesthesia of the lower lip and/or tongue, compared to the control group [mean (SD) 4.70 (0.94) vs 3.76 (1.50), p = 0.003]. The use of an educational video played on mobile tablets rather than a written pamphlet may lead to better understanding of the informed consent process in patients.

Evaluation of dental hygiene learning outcomes through smartphone-based educational slides targeting dental hygienists: A pilot study.

OBJECTIVE: Education reflecting fundamental knowledge is required for competent health care providers, but often lectures are not available for this purpose. This study aimed to evaluate the dental hygiene learning outcomes following the presentation of web-based slides on a smartphone to dental hygienists. METHODS: A two-group nonblinded quasi-experimental design was used for this study. Forty-six dental hygienists were assigned to a study (n = 31) or control group (n = 15). The study group viewed 22 slides on fundamental oral health knowledge using smartphones. Pre and postviewing tests (score range: 1-13) and a questionnaire were conducted to evaluate knowledge acquisition and to receive feedback from participants. Differences between the study and control group and intrastudy group differences were statistically evaluated. RESULTS: The fundamental knowledge of dental hygienists improved after viewing the slides: the study group had a significantly higher mean score than the control group (10.87 vs. 6.60; p < 0.001). Study group participants also had substantially higher post-test than pretest knowledge scores (mean 10.87 vs. 6.26, p < 0.001). In the questionnaire, more than 85% of the participants answered that the content of the slides would be useful in their clinical practice. CONCLUSION: Smartphone-based educational slides were beneficial for conveying fundamental and recent oral health knowledge to dental hygienists.

Evaluation of Inappropriate Positioning of Dosimeters in Medical Workers Based on Dose Equivalent Hp(10).

ABSTRACT: This report presents a new method to characterize the inappropriate positioning of dosimeters based on the dose equivalent Hp(10). The Hp(10) values of medical workers were measured monthly for 12 mo using two personal dosimeters. Using the ratio between the values of Hp(10) recorded from dosimeters worn over and under protective aprons [Hp(10) over and Hp(10) under , respectively], 670 pairs of dosimeter readings were categorized into a proper use group [Hp(10) over /Hp(10) under ≥ 5] and a misuse group [Hp(10) over /Hp(10) under < 5]. Following personal interviews, the readings in the misuse group were classified into the following six subgroups: "reversed," "sometimes reversed," "both under," "both over," "without apron," and "not specified." Ultimately, the scatter plot of "Hp(10) over - Hp(10) under " vs. Hp(10) over was identified as the most promising tool for clarifying the misuse patterns of dosimeters, as individual readings were mapped to the locations of the corresponding subgroups in the obtained graphs. Our results are expected to facilitate efficient and accurate usage of dosimeters by medical workers.

Study of Alveolar Bone Remodeling Using Deciduous Tooth Stem Cells and Hydroxyapatite by Vascular Endothelial Growth Factor Enhancement and Inhibition of Matrix Metalloproteinase-8 Expression in vivo.

Background: Periodontitis progression is characterized by alveolar bone loss, and its prevention is a major clinical problem in periodontal disease management. Matrix metalloproteinase-8 (MMP-8) has been shown to adequately monitor the treatment of chronic periodontitis patients as gingival crevicular fluid MMP-8s were positively associated with the severity of periodontal disease. Moreover, modulating the vascular endothelial growth factor (VEGF) levels in bones could be a good way to improve bone regeneration and cure periodontitis as VEGF promotes endothelial cell proliferation, proteolytic enzyme release, chemotaxis, and migration; all of which are required for angiogenesis. Purpose: The aim of this study was to determine the effect of hydroxyapatite incorporated with stem cells from exfoliated deciduous teeth (SHED) in Wistar rats' initial alveolar bone remodeling based on the findings of MMP-8 and VEGF expressions. Methods: A hydroxyapatite scaffold (HAS) in conjunction with SHED was transplanted into animal models with alveolar mandibular defects. A total of 10 Wistar rats (Rattus norvegicus) were divided into two groups: HAS and HAS + SHED. Immunohistochemistry staining was performed after 7 days to facilitate the examination of MMP-8 and VEGF expressions. Results: The independent t-test found significant downregulation of MMP-8 and upregulation VEGF expressions in groups transplanted with HAS in conjunction with SHED compared with the HAS group (p < 0.05). Conclusion: The combination of SHED with HAS on alveolar bone defects may contribute to initial alveolar bone remodeling as evident through the assessments of MMP-8 and VEGF expressions.

The Identification of Marker Genes for Predicting the Osteogenic Differentiation Potential of Mesenchymal Stromal Cells.

Mesenchymal stromal cells (MSCs) have the potential to differentiate into a variety of mature cell types and are a promising source of regenerative medicine. The success of regenerative medicine using MSCs strongly depends on their differentiation potential. In this study, we sought to identify marker genes for predicting the osteogenic differentiation potential by comparing ilium MSC and fibroblast samples. We measured the mRNA levels of 95 candidate genes in nine ilium MSC and four fibroblast samples before osteogenic induction, and compared them with alkaline phosphatase (ALP) activity as a marker of osteogenic differentiation after induction. We identified 17 genes whose mRNA expression levels positively correlated with ALP activity. The chondrogenic and adipogenic differentiation potentials of jaw MSCs are much lower than those of ilium MSCs, although the osteogenic differentiation potential of jaw MSCs is comparable with that of ilium MSCs. To select markers suitable for predicting the osteogenic differentiation potential, we compared the mRNA levels of the 17 genes in ilium MSCs with those in jaw MSCs. The levels of 7 out of the 17 genes were not substantially different between the jaw and ilium MSCs, while the remaining 10 genes were expressed at significantly lower levels in jaw MSCs than in ilium MSCs. The mRNA levels of the seven similarly expressed genes were also compared with those in fibroblasts, which have little or no osteogenic differentiation potential. Among the seven genes, the mRNA levels of IGF1 and SRGN in all MSCs examined were higher than those in any of the fibroblasts. These results suggest that measuring the mRNA levels of IGF1 and SRGN before osteogenic induction will provide useful information for selecting competent MSCs for regenerative medicine, although the effectiveness of the markers is needed to be confirmed using a large number of MSCs, which have various levels of osteogenic differentiation potential.

CHRONO and DEC1/DEC2 compensate for lack of CRY1/CRY2 in expression of coherent circadian rhythm but not in generation of circadian oscillation in the neonatal mouse SCN.

Clock genes Cry1 and Cry2, inhibitory components of core molecular feedback loop, are regarded as critical molecules for the circadian rhythm generation in mammals. A double knockout of Cry1 and Cry2 abolishes the circadian behavioral rhythm in adult mice under constant darkness. However, robust circadian rhythms in PER2::LUC expression are detected in the cultured suprachiasmatic nucleus (SCN) of Cry1/Cry2 deficient neonatal mice and restored in adult SCN by co-culture with wild-type neonatal SCN. These findings led us to postulate the compensatory molecule(s) for Cry1/Cry2 deficiency in circadian rhythm generation. We examined the roles of Chrono and Dec1/Dec2 proteins, the suppressors of Per(s) transcription similar to CRY(s). Unexpectedly, knockout of Chrono or Dec1/Dec2 in the Cry1/Cry2 deficient mice did not abolish but decoupled the coherent circadian rhythm into three different periodicities or significantly shortened the circadian period in neonatal SCN. DNA microarray analysis for the SCN of Cry1/Cry2 deficient mice revealed substantial increases in Per(s), Chrono and Dec(s) expression, indicating disinhibition of the transactivation by BMAL1/CLOCK. Here, we conclude that Chrono and Dec1/Dec2 do not compensate for absence of CRY1/CRY2 in the circadian rhythm generation but contribute to the coherent circadian rhythm expression in the neonatal mouse SCN most likely through integration of cellular circadian rhythms.

DEC1 regulates the rhythmic expression of PPARγ target genes involved in lipid metabolism in white adipose tissue.

Previously, we found that the basic helix-loop-helix transcriptional repressor DEC1 interacts with the PPARγ:RXRα heterodimer, a master transcription factor for adipogenesis and lipogenesis, to suppress transcription from PPARγ target genes (Noshiro et al., Genes to Cells, 2018, 23:658-669). Because the expression of PPARγ and several of its target genes exhibits circadian rhythmicity in white adipose tissue (WAT), we examined the expression profiles of PPARγ target genes in wild-type and Dec1-/- mice. We found that the expression of PPARγ target genes responsible for lipid metabolism, including the synthesis of triacylglycerol from free fatty acids (FFAs), lipid storage and the lipolysis of triacylglycerol to FFAs, oscillates in a circadian manner in WAT. Moreover, DEC1 deficiency led to a marked increase in the expression of these genes at night (Zeitgeber times 16 and 22), resulting in disruption of circadian rhythms. Serum FFA levels in wild-type mice also showed circadian oscillations, but these were disrupted by DEC1 deficiency, leading to reduced FFA levels. These results suggest that PPARγ:RXRα and DEC1 cooperatively generate the circadian expression of PPARγ target genes through PPAR-responsive elements in WAT.

Genetic Markers Can Predict Chondrogenic Differentiation Potential in Bone Marrow-Derived Mesenchymal Stromal Cells.

The precise predictions of the differentiation direction and potential of mesenchymal stromal cells (MSCs) are an important key to the success of regenerative medicine. The expression levels of fate-determining genes may provide tools for predicting differentiation potential. The expression levels of 95 candidate marker genes and glycosaminoglycan (GAG) contents after chondrogenic induction in 10 undifferentiated ilium and 5 jaw MSC cultures were determined, and their correlations were analyzed. The expression levels of eight genes before the induction of chondrogenic MSC differentiation were significantly correlated with the GAG levels after induction. Based on correlation patterns, the eight genes were classified into two groups: group 1 genes (AURKB, E2F1, CDKN2D, LIF, and ACLY), related to cell cycle regulation, and group 2 genes (CD74, EFEMP1, and TGM2), involved in chondrogenesis. The expression levels of the group 2 genes were significantly correlated with the ages of the cell donors. The expression levels of CDKN2D, CD74, and TGM2 were >10-fold higher in highly potent MSCs (ilium MSCs) than in MSCs with limited potential (jaw MSCs). Three-dimensional (3D) scatter plot analyses of the expression levels of these genes showed reduced variability between donors and confirmed predictive potential. These data suggest that group 2 genes are involved in age-dependent decreases in the chondrogenic differentiation potential of MSCs, and combined 3D analyses of the expression profiles of three genes, including two group 2 genes, were predictive of MSC differentiation potential.

Docosahexaenoic Acid Reduces Palmitic Acid-Induced Endoplasmic Reticulum Stress in Pancreatic Β Cells.

Endoplasmic reticulum (ER) stress leads to peripheral insulin resistance and the progression of pancreatic beta cell failure in type 2 diabetes. Although ER stress plays an important role in the pathogenesis of diabetes, it is indispensable for cellular activity. Therefore, when assessing the pathological significance of ER stress, it is important to monitor and quantify ER stress levels. Here, we have established a novel system to monitor ER stress levels quickly and sensitively, and using this method, we have clarified the effect of differences in glucose concentration and various fatty acids on the ER of pancreatic ß cells. First, we developed a cell system that secretes Gaussia luciferase in culture medium depending on the activation of the GRP78 promoter. This system could sensitively monitor ER stress levels that could not be detected with real-time RT-PCR and immunoblotting. This system revealed that hyperglycemia does not induce unfolded protein response (UPR) in a short period of time in MIN6 cells, a mouse pancreatic ß cell line. Physiological concentrations of palmitic acid, a saturated fatty acid, induced ER stress quickly, while physiological concentrations of oleic acid, an unsaturated fatty acid, did not. Docosahexaenoic acid, an n-3 unsaturated fatty acid, inhibited palmitic acid-induced ER stress. In this study, we have established a system that can sensitively detect ER stress levels of living cells in a short period of time. This system can be used to monitor the state of the ER in living cells and lead to the investigation of the significance of physiological or pathological ER stress levels.

Dec1 and CLOCK Regulate Na+/K+-ATPase ß1 Subunit Expression and Blood Pressure.

Blood pressure shows a circadian rhythm, and recent studies have suggested the involvement of a molecular clock system in its control. In the clock system, the CLOCK (circadian locomotor output cycles kaput):BMAL1 (brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein-1) heterodimer enhances promoter activity of clock genes, and DEC1 (BHLHE40/STRA13/SHARP-2) represses CLOCK/BMAL1-enhanced promoter activity through competition for binding to the clock element, CACGTG E-box. However, the molecular mechanisms by which this system regulates blood pressure remain unclear. Here, we show that DEC1 suppressed the expression of ATP1B1, which encodes the ß1 subunit of the Na+/K+-ATPase and elevated blood pressure. Using chromatin immunoprecipitation and chromatin immunoprecipitation-on-chip analyses, we found that DEC1 and CLOCK bound to E-boxes in the ATP1B1 promoter. Luciferase assays revealed that CLOCK:BMAL1 heterodimer enhanced transcription from the ATP1B1 promoter, whereas DEC1 suppressed this transactivation. Accordingly, Atp1b1 mRNA and protein levels in mouse kidney, aorta, and heart showed a circadian rhythm that was antiphasic to the blood pressure rhythm. Furthermore, Dec1-deficient mice showed enhanced Atp1b1 expression in these tissues and reduced blood pressure. In contrast, Clock-mutant mice showed reduced Atp1b1 expression and elevated blood pressure. Our results raise the possibility that transcriptional regulation of Atp1b1 by DEC1 and CLOCK:BMAL1 contributes to blood pressure.

Deficiency of the basic helix-loop-helix transcription factor DEC1 prevents obesity induced by a high-fat diet in mice.

Obesity is a major public health problem in developed countries resulting from increased food intake and decreased energy consumption and usually associated with abnormal lipid metabolism. Here, we show that DEC1, a basic helix-loop-helix transcription factor, plays an important role in the regulation of lipid consumption in mouse brown adipose tissue (BAT), which is the major site of thermogenesis. Homozygous Dec1 deletion attenuated high-fat-diet-induced obesity, adipocyte hypertrophy, fat volume and hepatic steatosis. Furthermore, DEC1 deficiency increased body temperature during daytime and enhanced the expression of uncoupler protein 1, a key factor of thermogenesis, and various lipolysis-related genes in interscapular BAT. In vitro experiments suggested that DEC1 suppresses the expression of various lipolysis-related genes induced by the heterodimer of peroxisome proliferator-activated receptor γ and retinoid X receptor α (RXRα) through direct binding to RXRα. These observations suggest that enhanced lipolysis in BAT caused by DEC1 deficiency leads to an increase in lipid consumption, thereby decreasing lipid accumulation in adipose tissues and the liver. Thus, DEC1 may serve as an energy-saving factor that suppresses lipid consumption, which may be relevant to managing obesity.

Differentiated embryo chondrocyte plays a crucial role in DNA damage response via transcriptional regulation under hypoxic conditions.

Tumor hypoxia contributes to a biologically aggressive phenotype and therapeutic resistance. Recent studies have revealed that hypoxia reduces expression of several DNA damage recognition and repair (DRR) genes via both hypoxia-inducible factor (HIF)-independent and -dependent pathways, and this induced genomic instability in cancer cells. We show here that one of the HIF-target genes-differentiated embryo chondrocyte (DEC)-plays a role in DNA damage response via transcriptional repression. Comprehensive gene expression and database analyses have revealed systemic repression of DNA-DRR genes in cancer and non-cancer cells under hypoxic conditions. Hypoxic repression in typical cases was confirmed by quantitative RT-PCR and promoter reporter experiments, and knockdown experiments indicated the critical role of DEC2 in such repression. Assessment of histone H2AX phosphorylation revealed that recognition and repair of DNA double-strand breaks (DSBs) induced by bleomycin or γ-ray irradiation were attenuated; moreover, Cleaved Caspase-3 levels were decreased with pre-conditioning under hypoxia: opposing phenomena were ascertained by knockdown of DEC2. Finally, pre-conditioning under hypoxia decreased the sensitivity of cancer cells to DSBs, and knockdown of DEC2 increased γ-ray sensitivity. These data imply that a critical reduction of DNA-DRR occurs via DEC-dependent transcriptional repression and suggest that DEC is a potential molecular target for anti-cancer strategies.

Role of MSX1 in Osteogenic Differentiation of Human Dental Pulp Stem Cells.

Msh homeobox 1 (MSX1) encodes a transcription factor implicated in embryonic development of limbs and craniofacial tissues including bone and teeth. Although MSX1 regulates osteoblast differentiation in the cranial bone of young animal, little is known about the contribution of MSX1 to the osteogenic potential of human cells. In the present study, we investigate the role of MSX1 in osteogenic differentiation of human dental pulp stem cells isolated from deciduous teeth. When these cells were exposed to osteogenesis-induction medium, runt-related transcription factor-2 (RUNX2), bone morphogenetic protein-2 (BMP2), alkaline phosphatase (ALPL), and osteocalcin (OCN) mRNA levels, as well as alkaline phosphatase activity, increased on days 4-12, and thereafter the matrix was calcified on day 14. However, knockdown of MSX1 with small interfering RNA abolished the induction of the osteoblast-related gene expression, alkaline phosphatase activity, and calcification. Interestingly, DNA microarray and PCR analyses revealed that MSX1 knockdown induced the sterol regulatory element-binding protein 2 (SREBP2) transcriptional factor and its downstream target genes in the cholesterol synthesis pathway. Inhibition of cholesterol synthesis enhances osteoblast differentiation of various mesenchymal cells. Thus, MSX1 may downregulate the cholesterol synthesis-related genes to ensure osteoblast differentiation of human dental pulp stem cells.

DEC2 is a negative regulator for the proliferation and differentiation of chondrocyte lineage-committed mesenchymal stem cells.

Differentiated embryo chondrocyte 2 (DEC2) is a basic helix-loop-helix-Orange transcription factor that regulates cell differentiation in various mammalian tissues. DEC2 has been shown to suppress the differentiation of mesenchymal stem cells (MSCs) into myocytes and adipocytes. In the present study, we examined the role of DEC2 in the chondrogenic differentiation of human MSCs. The overexpression of DEC2 exerted minimal effects on the proliferation of MSCs in monolayer cultures with the growth medium under undifferentiating conditions, whereas it suppressed increases in DNA content, glycosaminoglycan content, and the expression of several chondrocyte-related genes, including aggrecan and type X collagen alpha 1, in MSC pellets in centrifuge tubes under chondrogenic conditions. In the pellets exposed to chondrogenesis induction medium, DEC2 overexpression downregulated the mRNA expression of fibroblast growth factor 18, which is involved in the proliferation and differentiation of chondrocytes, and upregulated the expression of p16INK4, which is a cell cycle inhibitor. These findings suggest that DEC2 is a negative regulator of the proliferation and differentiation of chondrocyte lineage-committed mesenchymal cells.

Rhythmic expression of DEC2 protein in vitro and in vivo.

Basic helix-loop-helix (bHLH) transcription factor DEC2 (bHLHE41/Sharp1) is one of the clock genes that show a circadian rhythm in various tissues. DEC2 regulates differentiation, sleep length, tumor cell invasion and apoptosis. Although studies have been conducted on the rhythmic expression of DEC2 mRNA in various tissues, the precise molecular mechanism of DEC2 expression is poorly understood. In the present study, we examined whether DEC2 protein had a rhythmic expression. Western blot analysis for DEC2 protein revealed a rhythmic expression in mouse liver, lung and muscle and in MCF-7 and U2OS cells. In addition, AMP-activated protein kinase (AMPK) activity (phosphorylation of AMPK) in mouse embryonic fibroblasts (MEFs) exhibited a rhythmic expression under the condition of medium change or glucose-depleted medium. However, the rhythmic expression of DEC2 in MEF gradually decreased in time under these conditions. The medium change affected the levels of DEC2 protein and phosphorylation of AMPK. In addition, the levels of DEC2 protein showed a rhythmic expression in vivo and in MCF-7 and U2OS cells. The results showed that the phosphorylation of AMPK immunoreactivity was strongly detected in the liver and lung of DEC2 knockout mice compared with that of wild-type mice. These results may provide new insights into rhythmic expression and the regulation between DEC2 protein and AMPK activity.