45 research outputs found
An S.O.S. from the LGBT: Identifying Healthcare Barriers Among the LGBT Community
Introduction: Members of the Lesbian, Gay, Bisexual, and Transgender (LGBT) communities are a vulnerable population in accessing routine healthcare. Studies have indicated that LGBT individuals are at an increased risk for conditions regarding physical and mental health, as well as socioeconomic disparities; however, little is currently known regarding the leading causes of these discrepancies. This study aims to identify the leading causes that impede access to routine healthcare on behalf of the LGBT population.
Methodology: The Access Barriers to Care Index (ACBI) was sent to participants via the Internet over the course of three weeks. The survey assessed the level of significance of various factors that may impact access to healthcare services.
Results: The most common barriers to healthcare included inconvenient scheduling times, long wait times, the inability to leave work or school, or not having the financial resources to pay for healthcare services. There were no statistically significant differences in the responses given by homosexual participants in comparison to heterosexual participants.
Conclusions: Logistic and financial causes were the most influential barriers in accessing healthcare. Additional qualitative data among the LGBT community would be recommended in order to obtain more in depth information regarding barriers to healthcare services
Orai1 expression pattern in tooth and craniofacial ectodermal tissues and potential functions during ameloblast differentiation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113781/1/dvdy24307.pd
Rolipram, a Phosphodiesterase 4 Inhibitor, Stimulates Inducible cAMP Early Repressor Expression in Osteoblasts
Phosphodiesterase (PDE) 4 inhibitors have been shown to induce the cAMP-mediated signaling pathway by inhibiting cAMP hydrolysis. This study investigated the effect of a PDE4 inhibitor on the expression of the inducible cAMP early repressor (ICER), which is an endogenous inhibitor of CRE-mediated transcription, in osteoblastic cells. RT-PCR analysis revealed that rolipram, a PDE4 inhibitor, stimulates the ICER mRNA in a dose dependent manner. The induction of ICER mRNA expression by rolipram was suppressed by the inhibitors of protein kinase A (PKA) and p38 MAPK, suggesting the involvement of PKA and p38 MAPK activation in ICER expression by rolipram. It was previously shown that rolipram induced the expression of TNF-related activation-induced cytokine (TRANCE, also known as RANKL, ODF, or OPGL) in osteoblasts. This paper provides evidences that a transcriptional repressor like ICER might modulate TRANCE mRNA expression by rolipram in osteoblasts
Inducible cAMP early repressor expression and function in parathyroid hormone-treated osteoblasts
Parathyroid hormone (PTH) induces expression of several early response genes in osteoblasts, including prostaglandin G/H synthase-2 (PGHS-2). Early response gene expression is rapid, transient and does not require new protein synthesis. While pretreatment of osteoblastic MC3T3-E1 cells with the protein synthesis inhibitor cycloheximide does not prevent PTH-induced PGHS-2 expression, it does inhibit attenuation of PGHS-2 transcription. This suggests that PTH simultaneously induces expression of both PGHS-2 and a transcriptional inhibitor. One likely candidate is inducible CAMP early repressor (ICER), a member of the CAMP response element modulator family of basic leucine zipper transcription factors. We hypothesized that PTH induces ICER in osteoblasts and that ICER represses PTH-mediated gene expression. Our specific aim was to determine if ICER is an inducible, cAMP-dependent, early response gene that acts as a transcriptional repressor in PTH-treated osteoblasts. ^ PTH induced ICER mRNA and protein in osteoblastic MC3T3-E1 cells and cultured neonatal mouse calvariae in both a time- and dose-dependent manner. PTH also induced ICER mRNA expression in ROS 17/2.8, UMR-106, and Py1a osteoblastic cell lines. In all cells tested, ICER induction was rapid, transient, and did not require new protein synthesis, thus classifying ICER as an early response gene in PTH-treated cells. PTH also induced ICER mRNA in neonatal mouse calvariae in vivo. Unexpectedly, ICER mRNA was detectable in control-treated animals. Handling stress did not appear to affect this response. ^ PTH\u27s cellular effects are transduced by the PTH/PTHrP receptor, which is coupled to the cAMP-protein kinase A (PKA), protein kinase C (PKC), and calcium signaling pathways. To determine which pathways mediate PTH-induced ICER expression, MC3T3-E1 cells were treated with selective signaling agonists and antagonists. ICER expression was significantly induced only after cAMP-PKA activation. ^ Dose-dependent overexpression of ICER produced biphasic effects on a PGHS-1(−368/+6)-luciferase reporter vector. Low ICER overexpression enhanced, while high ICER overexpression repressed, basal and induced promoter activity. Mutation of the AP-1 site mimicked ICER\u27s effect on the wild type. ^ Based on these studies, we conclude that ICER is a PTH-inducible, cAMP-dependent early response gene that represses PTH-mediated gene transcription in osteoblasts. However, low concentrations of ICER may also enhance PGHS-1 promoter activity, suggesting that ICER is not strictly a transcriptional repressor.
Three-Dimensional Force Measurements During Rapid Palatal Expansion in Sus scrofa
Rapid palatal expansion is an orthodontic procedure widely used to correct the maxillary arch. However, its outcome is significantly influenced by factors that show a high degree of variability amongst patients. The traditional treatment methodology is based on an intuitive and heuristic treatment approach because the forces applied in the three dimensions are indeterminate. To enable optimal and individualized treatment, it is essential to measure the three-dimensional (3D) forces and displacements created by the expander. This paper proposes a method for performing these 3D measurements using a single embedded strain sensor, combining experimental measurements of strain in the palatal expander with 3D finite element analysis (FEA). The method is demonstrated using the maxillary jaw from a freshly euthanized pig (Sus scrofa) and a hyrax-design rapid palatal expander (RPE) appliance with integrated strain gage. The strain gage measurements are recorded using a computer interface, following which the expansion forces and extent of expansion are estimated by FEA. A total activation of 2.0 mm results in peak total force of about 100 N—almost entirely along the direction of expansion. The results also indicate that more than 85% of the input activation is immediately transferred to the palate and/or teeth. These studies demonstrate a method for assessing and individualizing expansion magnitudes and forces during orthopedic expansion of the maxilla. This provides the basis for further development of smart orthodontic appliances that provide real-time readouts of forces and movements, which will allow personalized, optimal treatment
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Different duration of parathyroid hormone exposure distinctively regulates primary response genes Nurr1 and RANKL in osteoblasts.
Parathyroid hormone (PTH) exerts dual effects, anabolic or catabolic, on bone when administrated intermittently or continuously, via mechanisms that remain largely unknown. PTH binding to cells induces PTH-responsive genes including primary response genes (PRGs). PRGs are rapidly induced without the need for de novo protein synthesis, thereby playing pivotal roles in directing subsequent molecular responses. In this study, to understand the role of PRGs in mediating osteoblastic cellular responses to PTH, we investigated whether various durations of PTH differentially induce PRGs in primary osteoblasts and MC3T3-E1. Nurr1 and RANKL, PRGs known for their anabolic and catabolic roles in bone metabolism respectively, presented distinctive transient vs. sustained induction kinetics. Corroborating their roles, maximum induction of Nurr1 was sufficiently achieved by brief PTH in as little as 30 minutes and continued beyond that, while maximum induction of RANKL was achieved only by prolonged PTH over 4 hours. Our data suggested distinctive regulatory mechanisms for Nurr1 and RANKL: PKA-mediated chromatin rearrangement for transcriptional regulation of both PRGs and ERK-mediated transcriptional regulation for RANKL but not Nurr1. Lastly, we classified PRGs into two groups based on the induction kinetics: The group that required brief PTH for maximum induction included Nur77, cox-2, and Nurr1, all of which are reported to play roles in bone formation. The other group that required prolonged PTH for maximum induction included IL-6 and RANKL, which play roles in bone resorption. Together, our data suggested the crucial role of PRG groups in mediating differential osteoblastic cellular responses to intermittent vs. continuous PTH. Continued research into the regulatory mechanisms of PKA and ERK for PRGs will help us better understand the molecular mechanisms underlying the dual effects of PTH, thereby optimizing the current therapeutic use of PTH for osteoporosis
Different duration of parathyroid hormone exposure distinctively regulates primary response genes Nurr1 and RANKL in osteoblasts.
Parathyroid hormone (PTH) exerts dual effects, anabolic or catabolic, on bone when administrated intermittently or continuously, via mechanisms that remain largely unknown. PTH binding to cells induces PTH-responsive genes including primary response genes (PRGs). PRGs are rapidly induced without the need for de novo protein synthesis, thereby playing pivotal roles in directing subsequent molecular responses. In this study, to understand the role of PRGs in mediating osteoblastic cellular responses to PTH, we investigated whether various durations of PTH differentially induce PRGs in primary osteoblasts and MC3T3-E1. Nurr1 and RANKL, PRGs known for their anabolic and catabolic roles in bone metabolism respectively, presented distinctive transient vs. sustained induction kinetics. Corroborating their roles, maximum induction of Nurr1 was sufficiently achieved by brief PTH in as little as 30 minutes and continued beyond that, while maximum induction of RANKL was achieved only by prolonged PTH over 4 hours. Our data suggested distinctive regulatory mechanisms for Nurr1 and RANKL: PKA-mediated chromatin rearrangement for transcriptional regulation of both PRGs and ERK-mediated transcriptional regulation for RANKL but not Nurr1. Lastly, we classified PRGs into two groups based on the induction kinetics: The group that required brief PTH for maximum induction included Nur77, cox-2, and Nurr1, all of which are reported to play roles in bone formation. The other group that required prolonged PTH for maximum induction included IL-6 and RANKL, which play roles in bone resorption. Together, our data suggested the crucial role of PRG groups in mediating differential osteoblastic cellular responses to intermittent vs. continuous PTH. Continued research into the regulatory mechanisms of PKA and ERK for PRGs will help us better understand the molecular mechanisms underlying the dual effects of PTH, thereby optimizing the current therapeutic use of PTH for osteoporosis
Expression of Inducible Camp Early Repressor Is Coupled to the Camp-Protein Kinase a Signaling Pathway in Osteoblasts
We previously showed that parathyroid hormone (PTH) induces inducible cAMP early repressor (ICER) in osteoblastic cells and mouse calvariae. PTH signaling in osteoblastic cells is transduced by PTH receptor 1, which is coupled to cAMP-protein kinase A (PKA), protein kinase C (PKC). and calcium signaling pathways. In the present study, we examined the role of these pathways in mediating PTH-induced ICER mRNA and protein expression in osteoblastic MC3T3-E1 cells. Using RT-PCR, we found that PTH(1-34), forskolin (FSK), and 8-bromo-cAMP (8Br-cAMP) induced ICER expression, while phorbol myristate acetate (PMA), ionomycin, and PTH(3-34) did not. Similar results were found for the induction of ICER protein. PKA inhibition by H89 markedly reduced PTH- and FSK-induced ICER expression, while PKC depletion by PMA had little effect. We also tested ICER induction by other osteotropic signaling agonists. Other cAMP-PKA pathway activators, such as PTH-related protein (PTHrP), induced ICER expression, while agents that signal through other pathways did not. PTHrP maximally induced ICER mRNA at 2-4 h, which then returned to baseline by 10 h. Finally, PTH, FSK, and PTHrP induced ICER in cultured mouse calvariae and osteoblastic ROS 17/2.8, UMR-106, and Pyla cells. We conclude that ICER expression in osteoblasts requires activation of the cAMP-PKA signaling pathway
Deletion of Orai1 leads to bone loss aggravated with aging and impairs function of osteoblast lineage cells
Osteoblast lineage cells, a group of cells including mesenchymal progenitors, osteoblasts, and osteocytes, are tightly controlled for differentiation, proliferation and stage-specific functions in processes of skeletal development, growth and maintenance. Recently, the plasma membrane calcium channel Orai1 was highlighted for its role in skeletal development and osteoblast differentiation. Yet the roles of Orai1 in osteoblast lineage cells at various stages of maturation have not been investigated. Herein we report the severe bone loss that occurred in Orai1−/− mice, aggravated by aging, as shown by the microcomputed tomography (mCT) and bone histomorphometry analysis of 8-week and 12-week old Orai1−/− mice and sex-matched WT littermates. We also report that Orai1 deficiency affected the differentiation, proliferation, and type I collagen secretion of primary calvarial osteoblasts, mesenchymal progenitors, and osteocytes in Orai1−/− mice; specifically, our study revealed a significant decrease in the expression of osteocytic genes Fgf23, DMP1 and Phex in the cortical long bone of Orai1−/− mice; a defective cellular and nuclear morphology of Orai1−/− osteocytes; and defective osteogenic differentiation of Orai1−/− primary calvarial osteoblasts (pOBs), including a decrease in extracellular-secretion of type I collagen. An increase in the mesenchymal progenitor population of Orai1−/− bone marrow cells was indicated by a colony forming unit-fibroblasts (CFU-F) assay, and the increased proliferation of Orai1−/− pOBs was indicated by an MTT assay. Notably, Orai1 deficiency reduced the nuclear localization and transcription activity of the Nuclear Factor of Activated T-cell c1 (NFATc1), a calcium-regulated transcription factor, in pOBs. Altogether, our study demonstrated the crucial role of Orai1 in bone development and maintenance, via its diverse effects on osteoblast lineage cells from mesenchymal progenitors to osteocytes. Keywords: Orai1, Osteoblast lineage cells, Bone, Knockout mic