The main objective of this study was to map global gene expression in order to provide information about the populations of mRNA species participating in murine tooth development at 24 h intervals, ...starting at the 11th embryonic day (E11.5) up to the 7th post-natal day (P7). The levels of RNA species expressed during murine tooth development were mesured using a total of 58 deoxyoligonucleotide microarrays. Microarray data was validated using real-time RT-PCR. Differentially expressed genes (p < 0.05) were subjected to bioinformatic analysis to identify cellular activities significantly associated with these genes. Using ANOVA the microarray data yielded 4362 genes as being differentially expressed from the 11th embryonic day (E11.5) up to 7 days post-natal (P7), 1921 of these being genes without known functions. The remaining 2441 genes were subjected to further statistical analysis using a supervised procedure. Bioinformatic analysis results for each time-point studied suggests that the main molecular functions associated with genes expressed at the early pre-natal stages (E12.5-E18.5) were cell cycle progression, cell morphology, lipid metabolism, cellular growth, proliferation, senescence and apoptosis, whereas most genes expressed at post-natal and secretory stages (P0-P7) were significantly associated with regulation of cell migration, biosynthesis, differentiation, oxidative stress, polarization and cell death. Differentially expressed genes (DE) not described earlier during murine tooth development; Inositol 1, 4, 5-triphosphate receptor 3 (Itpr3), metallothionein 1(Mt1), cyclin-dependent kinase 4 (Cdk4), cathepsin D (Ctsd), keratin complex 2, basic, gene 6a (Krt2-6a), cofilin 1, non-muscle (Cfl1), cyclin 2 (Ccnd2), were verified by real-time RT-PCR.
Long-term antiresorptives use has been linked to atypical subtrochanteric and diaphyseal femoral fractures (AFF), the pathogenesis of which is still unknown. In the present case report we present the ...results of analysis of bone chips from a 74-year old female patient that had been on alendronate, ibandronate and denosumab treatment, and who sustained an atypical femoral fracture, by histology, quantitative backscattered electron imaging, and Raman spectroscopic analysis. The results indicate ongoing osteoclastic resorption, but also several abnormalities: 1) an altered arrangement of osteons; 2) impaired mineralization; 3) the presence of pyrophosphate, which might contribute to the impaired mineralization evident in the present case. Taken together, these changes may contribute to the focally reduced bone strength of this patient.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Osteoarthritis (OA) is affecting large proportions of the population worldwide. So far, no effective disease modifying drug has been developed for this disease, limiting the therapeutic options to ...pain medications, physiotherapy and ultimately surgical approaches, mainly joint implant surgery. In vitro and animal studies have demonstrated that bisphosphonates have the potential to become effective modalities for the treatment of OA. This group of pharmacological agents modulates crucial aspects of OA pathogenesis (subchondral bone turnover and loss, bone marrow edema formation, cartilage degeneration and synovitis), and have shown clear efficacy in animal models of OA. Human studies have, however, so far been disappointing with only one of six clinical studies showing clear short-term efficacy. Possible reasons for these discrepancies will be discussed.
•Preclinical studies suggest significant effects of bisphosphonates on a wide variety of factors involved in OA pathogenesis•Bisphosphonates reduce bone turnover and reduction of subchondral bone turnover seems to reduce articular cartilage deterioration•Bone marrow lesions, which play an integral role in OA pathogenesis, are areas of high bone turnover and increased vascularization, - two characteristics amenable to modulation by bisphosphonate treatment•Bisphosphonate treatment has shown disease modifying effects in a wide variety of animal models•Future studies of bisphosphoantes in OA should focus on appropriate dosing and improved selection of suitable patients with this heterogenous disease
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Summary Objective Bone marrow lesions (BML), previously denoted bone marrow edema, are detected as water signals by magnetic resonance imaging (MRI). Previous histologic studies were unable to ...demonstrate any edematous changes at the tissue level. Therefore, our aim was to investigate the underlying biological mechanisms of the water signal in MRI scans of bone affected by BML. Methods Tetracycline labeling in addition to water sensitive MRI scans of 30 patients planned for total hip replacement surgery was undertaken. Twenty-one femoral heads revealed BML on MRI, while nine were negative and used as controls (CON). Guided by the MRI images cylindrical biopsies were extracted from areas with BML in the femoral heads. Tissue sections from the biopsies were subjected to histomorphometric image analyses of the cancellous bone envelope. Results patients with BML exhibited an average 40- and 18-fold increase of bone formation rate and mineralizing surfaces, respectively. Additionally, samples with BML demonstrated 2-fold reduction of marrow fat and 28 fold increase of woven bone Immunohistochemical analysis showed a 4 fold increase of angiogenesis markers CD31 and von Willebrand Factor in the BML-group compared to controls. Conclusion this study indicates that BML are characterized by increased bone turnover, vascularity and angiogenesis in keeping with it being a reparatory process. Thus, the water signal, which is the hallmark of BML on MRI, is most probably reflecting increased tissue vascularity accompanying increased remodeling activity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Dental Health Services Response to COVID-19 in Norway Stangvaltaite-Mouhat, Lina; Uhlen, Marte-Mari; Skudutyte-Rysstad, Rasa ...
International journal of environmental research and public health,
08/2020, Volume:
17, Issue:
16
Journal Article
Peer reviewed
Open access
We aimed to investigate the management of urgent dental care, the perception of risk and workplace preparedness among dental staff in Norway during the COVID-19 pandemic. An electronic questionnaire ...regarding the strictest confinement period in Norway (13 March-17 April 2020) was distributed to dental staff. Among the 1237 respondents, 727 (59%) treated patients, of whom 170 (14%) worked in clinics designated to treat patients suspected or confirmed to have COVID-19. Out of them 88% (143) received training and 64% (103) simulation in additional infection prevention procedures, while 27 (24%) respondents reported deviation. In total, 1051 (85%) respondents perceived that dental staff had a high risk of being infected, 1039 (84%) that their workplace handled the current situation well, 767 (62%) that their workplace had adequate infection control equipment and 507 (41%) agreed that their workplace is well equipped to handle an escalation. Before an appointment, 1182 (96%) respondents always/often inquired per phone information if a patient experienced symptoms of COVID-19, and 1104 (89%) asked about a history of travel to affected areas. Twice as many patients on average per week were treated by phone than in a clinic. A lower proportion of dental staff in high incidence counties applied additional infection prevention measures compared to low and medium incidence counties. To conclude, urgent dental health care was managed relatively well in Norway. Additional training of the dental staff in adequate infection prevention and step-by-step procedures may be needed. These results may be used to improve the dental health service's response to future outbreaks.
Aim
To assess tissue level changes of proteome and cytokine profiles of subchondral bone in hip osteoarthritis (OA) affected by bone marrow lesions (BMLs). We compared significant protein level ...differences in osteoarthritic bone with BMLs to control bone without bone marrow lesions.
Methods
Subchondral bone biopsies were taken from femoral heads of end‐stage osteoarthritis patients with (BML, n = 21) and without (CON, n = 9) BMLs. Proteins were extracted through a standardized Trizol protocol and used in the subsequent analyses. Angiogenesis and bone markers were assessed using multiplex immunoassays (Luminex). Liquid chromatography tandem mass spectrometry (LC‐MS/MS) was performed to detect significant differences in proteome and peptide profiles between BML and CON.
Results
Multiplex immunoassays revealed increased tissue contents of vascular endothelial growth factors (VEGF‐A/C/D), endothelin‐1, angiopoietin‐2 and interleukin‐6 (IL‐6) in bone with BMLs compared to control bone, whereas osteoprotegerin levels were reduced. Mass spectrometry demonstrated pronounced increase in the levels of hemoglobin (73‐fold), serum albumin (30‐fold), alpha‐1‐antitrypsin (9‐fold), apolipoprotein A1 (4.7‐fold), pre‐laminin‐A/C (3.7‐fold) and collagen‐alpha1‐XII (3‐fold) in BMLs, while aggrecan core protein (ACAN) and hyaluronan and proteoglycan link protein 1 (HAPL1) decreased 37‐ and 29‐fold respectively.
Conclusion
Reduced osteoprotegerin, ACAN and HAPL1 are consistent with osteoclastic activation and high remodeling activity in BMLs. The pronounced increase in angiogenesis markers, hemoglobin and serum albumin support the presence of increased vascularity in subchondral bone affected by BMLs in OA. VEGFs and IL‐6 are known nociceptive modulators, and increased levels are in keeping with pain being a clinical feature frequently associated with BMLs.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Tannhelsetjenestens kompetansesenter Øst (TkØ) har gjennomført en spørreundersøkelse om tannhelsepersonells erfaringer under nedstenging i perioden 13. mars–17. april 2020. Første del av studien er ...nå publisert i International Journal of Environmental Research and Public Health og er den første norske studien som omhandler håndtering av covid-19-pandemien i tannhelsetjenesten.
Epidemiological studies suggest an increased fracture risk in patients taking proton pump inhibitors (PPIs) for long term. The underlying mechanism, however, has been disputed. By binding to the ...gastric proton pump, PPIs inhibit gastric acid secretion. We have previously shown that proton pump (H+/K+ATPase beta subunit) KO mice exhibit reduced bone mineral density (BMD) and inferior bone strength compared with WT mice. Patients using PPIs as well as these KO mice exhibit gastric hypoacidity, and subsequently increased serum concentrations of the hormone gastrin. In this study, we wanted to examine whether inhibition of the gastrin/CCK2 receptor influences bone quality in these mice. KO and WT mice were given either the gastrin/CCK2 receptor antagonist netazepide dissolved in polyethylene glycol (PEG) or only PEG for 1year. We found significantly lower bone mineral content and BMD, as well as inferior bone microarchitecture in KO mice compared with WT. Biomechanical properties by three-point bending test also proved inferior in KO mice. KO mice receiving netazepide exhibited significantly higher cortical thickness, cortical area fraction, trabecular thickness and trabecular BMD by micro-CT compared with the control group. Three-point bending test also showed higher Young’s modulus of elasticity in the netazepide KO group compared with control mice. In conclusion, we observed that the gastrin receptor antagonist netazepide slightly improved bone quality in this mouse model, suggesting that hypergastrinemia may contribute to deteriorated bone quality during acid inhibition.
Biofilm formation on dental abutment may lead to peri-implant mucositis and subsequent peri-implantitis. These cases are clinically treated with antibiotics such as doxycycline (Doxy). Here we used ...an electrochemical method of cathodic polarization to coat Doxy onto the outer surface of a dental abutment material. The Doxy-coated surface showed a burst release in phosphate-buffered saline during the first 24 h. However, a significant amount of Doxy remained on the surface for at least 2 weeks especially on a 5 mA-3 h sample with a higher Doxy amount, suggesting both an initial and a long-term bacteriostatic potential of the coated surface. Surface chemistry was analyzed by x-ray photoelectron spectroscopy and secondary ion mass spectrometry. Surface topography was evaluated by field emission scanning electron microscopy and blue-light profilometry. Longer polarization time from 1 h to 5 h and higher current density from 1 to 15 mA cm−2 resulted in a higher amount of Doxy on the surface. The surface was covered by a layer of Doxy less than 100 nm without significant changes in surface topography. The antibacterial property of the Doxy-coated surface was analyzed by biofilm and planktonic growth assays using Staphylococcus epidermidis. Doxy-coated samples reduced both biofilm accumulation and planktonic growth in broth culture, and also inhibited bacterial growth on agar plates. The antibacterial effect was stronger for samples of 5 mA-3 h coated with a higher amount of Doxy compared to that of 1 mA-1 h. Accordingly, an abutment surface coated with Doxy has potential for preventing bacterial colonization when exposed to the oral cavity. Doxy-coating could be a viable way to control peri-implant mucositis and prevent its progression into peri-implantitis.
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