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1.
Article in English | WPRIM | ID: wpr-922603

ABSTRACT

OBJECTIVES@#Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 can damage the myocardium directly, or activate the immune system, trigger a cytokine storm, and cause inflammatory cells to infiltrate the myocardial tissue and damage the myocardium. This study is based on the sequencing data to analyze the changes in gene expression of cardiomyocytes and macrophages after SARS-CoV-2 infection, and explore the potential effects of SARS-CoV-2 on the heart and immune system.@*METHODS@#The public data set GSE151879 was retrieved. The online software Network Analyst was used to preprocess the data, and the differentially expressed genes (DEGs) [log@*RESULTS@#After data standardization, the data quality was excellent and it can ensure reliable results. Myocardial cell infection with SARS-CoV-2 and gene expression spectrum were changed significantly, including a total of 484 DEGs in adult cardiomyoblasts, a total of 667 DEGs in macrophages, and a total of 1 483 DEGs in human embryo source of cardiomyopathy. The Stum, mechanosensory transduction mediator homolog (STUM), dehydrogenase/reductase 9 (DHRS9), calcium/calmodulin dependent protein kinase II beta (CAMK2B), claudin 1(CLDN1), C-C motif chemokine ligand 2 (CCL2), TNFAIP3 interacting protein 3 (TNIP3), G protein-coupled receptor 84 (GPR84), and C-X-C motif chemokine ligand 1 (CXCL1) were identical in expression patterns in 3 types of cells. The protein-protein interaction suggested that CAMK2B proteins may play a key role in the antiviral process in 3 types of cells; and silicon dioxide (SiO@*CONCLUSIONS@#CAMK2B, CLDN1, CCL2, and DHRS9 genes play important roles in the immune response of cardiomyocytes against SARS-CoV-2. SiO


Subject(s)
COVID-19 , Humans , Macrophages , Myocytes, Cardiac , SARS-CoV-2 , Silicon Dioxide , Transcriptome
2.
Braz. dent. j ; 31(2): 164-170, Mar.-Apr. 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132289

ABSTRACT

Abstract The aim of this study was to compare the effects of a single application of a new calcium mesoporous silica nanoparticle (Ca2+-MSN) versus other calcium and/or fluoride products against dental erosion. Enamel blocks were half-covered and assigned to six groups (n = 10): Ca2+-MSNs; casein phosphopeptide-amorphous calcium phosphate mousse (CPP-ACP); CPP-ACP/F− (900 ppm F−); titanium tetrafluoride (TiF4 1%); sodium fluoride (NaF 1.36%); and Milli-Q® water (negative control). A single application for each product was completed on the exposed areas of the blocks and were submitted to an erosive challenge. Differences in volumetric roughness (Sa), and tooth structure loss (TSL) by use of three-dimensional noncontact optical profilometry were evaluate. Scanning electron microscopy (SEM) was performed. Analysis of variance and Tukey's test for Sa and the Kruskal-Wallis and Mann-Whitney U tests (p< 0.05) for TSL, respectively. Results: When evaluating Sa, all products presented differences in roughness when compared with the control group (p< 0.05) but not with each other (p > 0.05). However, when analyzing the TSL, it was observed that Ca2+-MSNs, TiF4, and NaF were more effective in preventing dental erosion versus CPP-ACP, CPP-ACP/F−, and Milli-Q® water (p< 0.05). In the SEM images, the negative control presented the worst loss of dental structure, with more porous enamel. Ca2+-MSNs were as effective as TiF4 and NaF to reduce the tooth structure loss.


Resumo O objetivo deste estudo foi comparar os efeitos de uma única aplicação de uma nova nanopartícula de sílica mesoporosa de cálcio (Ca2+ -MSN) versus outros produtos à base de cálcio e / ou fluoreto contra a erosão dentária. Blocos de esmalte foram parcialmente cobertos e distribuídos em seis grupos (n = 10): Ca2+ -MSNs; fosfopeptídeos de caseína/fosfato de cálcio amorfo (CPP-ACP); CPP-ACP / F- (900 ppm F-); tetrafluoreto de titânio (TiF4 1%); fluoreto de sódio (NaF 1,36%); e água Milli-Q® (controle negativo). Uma única aplicação para cada produto foi realizada nas áreas expostas dos blocos e submetida a desafio erosivo. Diferenças na rugosidade volumétrica (Sa) e na perda de estrutura dentária (TSL) por meio de perfilometria tridimensional de não contato foram avaliadas. Microscopia eletrônica de varredura (MEV) foi realizada. Foram realizadas análise de variância e teste de Tukey para os testes Sa e Kruskal-Wallis e Mann-Whitney (p<0,05) para TSL, respectivamente. Na avaliação de Sa, todos os produtos apresentaram diferenças de rugosidade quando comparados ao grupo controle (p<0,05), mas não entre si (p> 0,05). No entanto, ao analisar o TSL, observou-se que Ca2+ -MSNs, TiF4 e NaF foram mais eficazes na prevenção da erosão dental versus CPP-ACP, CPP-ACP / F- e Milli-Q® (p<0,05). Nas imagens de MEV, o controle negativo apresentou a pior perda de estrutura dentária, com o esmalte mais poroso. A Ca2+ -MSNs foi tão eficaz quanto o TiF4 e o NaF para reduzir a perda da estrutura dentária.


Subject(s)
Humans , Tooth Erosion , Fluorides , Sodium Fluoride , Tooth Remineralization , Caseins , Calcium , Silicon Dioxide , Dental Enamel
4.
Article in Chinese | WPRIM | ID: wpr-828206

ABSTRACT

As a new potential bone graft material, tissue engineered bone effectively compensates for the defects of today's bone repair materials. Meanwhile, mesoporous silica nanomaterials(MSNs) have been widely recognized due to their large specific surface area, good biocompatibility, and capability of further processing and modification. They have promising application prospects in bone tissue engineering. For the basic scientific research results that have been carried out in the early stage, the basic characteristics of mesoporous silica nano biomaterials and their application advantages, research status and development prospects in bone tissue engineering are reviewed. As for the research status, there are two aspects--as a carrier or as a component of engineering scaffolds. For the first aspect, different kinds of loaded drugs and different loading methods are reviewed. For the second, microstructure and mechanical properties of various complex scaffolds containing MSNs and the molecular and cellular behavior of seeded cells on these scaffolds are reviewed. The research of MSNs in bone cements and metal ions doped MSNs in bone tissue engineering are also included. The future development of MSNs in bone tissue engineering is also discussed.


Subject(s)
Bone and Bones , Nanoparticles , Porosity , Silicon Dioxide , Tissue Engineering
6.
Article in English | WPRIM | ID: wpr-811433

ABSTRACT

PURPOSE: The aim of this study was to evaluate the microshear bond strength (µSBS) of four computer-aided design/computer-aided manufacturing (CAD/CAM) blocks repaired with composite resin using three different surface treatment protocols.MATERIALS AND METHODS: Four different CAD/CAM blocks were used in this study: (1) flexible hybrid ceramic (FHC), (2) resin nanoceramic (RNC), (c) polymer infiltrated ceramic network (PICN) and (4) feldspar ceramic (FC). All groups were further divided into four subgroups according to surface treatment: control, hydrofluoric acid etching (HF), air-borne particle abrasion with aluminum oxide (AlO), and tribochemical silica coating (TSC). After surface treatments, silane was applied to half of the specimens. Then, a silane-containing universal adhesive was applied, and specimens were repaired with a composite, Next, μSBS test was performed. Additional specimens were examined with a contact profilometer and scanning electron microscopy. The data were analyzed with ANOVA and Tukey tests.RESULTS: The findings revealed that silane application yielded higher µSBS values (P<.05). All surface treatments were showed a significant increase in µSBS values compared to the control (P<.05). For FHC and RNC, the most influential treatments were AlO and TSC (P<.05).CONCLUSION: Surface treatment is mandatory when the silane is not preferred, but the best bond strength values were obtained with the combination of surface treatment and silane application. HF provides improved bond strength when the ceramic content of material increases, whereas AlO and TSC gives improved bond strength when the composite content of material increases.


Subject(s)
Adhesives , Aluminum Oxide , Ceramics , Clinical Protocols , Dental Bonding , Dental Restoration Repair , Hydrofluoric Acid , Microscopy, Electron, Scanning , Polymers , Shear Strength , Silicon Dioxide
7.
Braz. oral res. (Online) ; 34: e110, 2020. graf
Article in English | LILACS, BBO | ID: biblio-1132720

ABSTRACT

Abstract Acrylic resin has been used in the manufacture of prostheses, however, in the oral cavity, this material starts to retain microorganisms capable of causing gingival inflammation due its porosities. The aim of this study was to evaluate the influence of the use of silicon dioxide as a coating layer applied onto acrylic resin, on the adhesion of Candida albicans (Ca). After the incubation period in Sabouraud Dextrose Broth, a total of 1 ml of the Ca suspension was added to plate wells, each well containing a specimen of acrylic resin. The adhesion ability of Ca on acrylic resin was determined by counting colonies. Three groups (n = 6) of acrylic resin were assessed: with polishing (RP); without polishing (RW); with polishing and coating layer of silicon dioxide (RPC). Ca deposited on the surface of the acrylic resin was also observed using Scanning Electron Microscopy (SEM). Statistical assessment by Kruskal-Wallis and Student-Newman-Keuls Method were done (α = 2%). There was significant difference among the groups. The RPC group showed the lowest growth, with an average of 5.59 Log CFU/cm 2 ; there was a statistically significant difference in relation to group RW, which presented a growth of 6.07 Log CFU/cm 2 and to group RP with 5.91 Log CFU/cm 2 (p < 000.1). SEM images demonstrated that in the RP and RPC group, the surface of the resin had greater regularity, and smaller number of microorganisms. The application of silicon dioxide coating on acrylic resin appears to be a promising alternative, and its use can help in reducing the adhesion of Ca in prostheses.


Subject(s)
Candida albicans , Surface Properties , Acrylic Resins , Silicon Dioxide , Denture Bases
8.
J. appl. oral sci ; 28: e20200131, 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1134780

ABSTRACT

Abstract Objective There is increasingly common the consumption more times a day of foods and acidic drinks in the diet of the population. The present study aimed to evaluate and compare the effects of a calcium mesoporous silica nanoparticle single application of other calcium and/or fluoride products in reducing the progression of dental erosion. Methodology Half of the eroded area was covered of 60 blocks of enamel, after which the block was submitted to the following treatments: (Ca2+-MSN), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP); CPP-ACP/F-(900 ppm F−); titanium tetrafluoride (TiF4 1%) (positive control); sodium fluoride (NaF 1.36%) (positive control); and Milli-Q® water (negative control) before being submitted to a second erosive challenge. A surface analysis was performed via a three-dimensional (3D) noncontact optical profilometry to assess the volumetric roughness (Sa) and tooth structure loss (TSL) and and through scanning electron microscopy (MEV). An analysis of variance (ANOVA) and Tukey's test were performed. Results Regarding Sa, all experimental groups exhibited less roughness than the control (p<0.05). The TSL analysis revealed that the Ca2+-MSN and NaF groups were similar (p>0.05) and more effective in minimizing tooth loss compared with the other groups (p<0.05). Conclusions The Ca2+-MSN and NaF treatments were superior compared with the others and the negative control.


Subject(s)
Humans , Tooth Erosion , Tooth Remineralization , Nanoparticles , Sodium Fluoride , Caseins , Calcium , Silicon Dioxide , Fluorides
9.
Braz. J. Pharm. Sci. (Online) ; 56: e17560, 2020. tab, graf
Article in English | LILACS | ID: biblio-1285514

ABSTRACT

Urea's thermal instability and burning on sensitive skin can cause problems for cosmetic formulations. To overcome these drawbacks, urea was incorporated into ordered mesoporous silica (SBA-15). SBA-15 was synthesized using tetraethyl orthosilicate and Pluronic® P123 in an acid medium. Urea (20 wt.%) was incorporated into calcined SBA-15 by the incipient wetness impregnation method. Several techniques were used to characterize the samples. Skin hydration and transepidermal water loss were measured using Corneometer® CM 825 PC and Tewameter® 300 TM. Results showed that the structural properties of SBA-15Urea were similar to pure SBA-15, indicating that SBA-15 remained structured even after urea incorporation. Nitrogen physisorption data showed the volume and surface area of the pores in SBA-15Urea were much lower than those in SBA-15, demonstrating that urea was deposited inside the mesopores. In vivo moisturization studies revealed that SBA-15Urea was not able to reduce transepidermal water loss compared to the other products and control, while forming a non-occlusive surface film on the skin. We conclude that incorporation of urea in the pores of the inorganic SBA-15 matrix is a promising approach to enhancing its stability and providing a prolonged moisturizing effect.


Subject(s)
Urea/analysis , Silicon Dioxide/administration & dosage , Skin/drug effects , Control , Fluid Therapy/adverse effects
10.
Braz. dent. j ; 30(6): 599-606, Nov.-Dec. 2019. tab, graf
Article in English | LILACS | ID: biblio-1055458

ABSTRACT

Abstract The aim of this study was to evaluate the subcutaneous connective tissue response of isogenic mice after implantation of different glass ionomer-based cements (EQUIA® Forte Fil, EQUIA® Fil and Ketac™ Universal Aplicap™). Eighty-seven isogenic BALB/c mice were allocated in 12 groups, 9 were considered as experimental groups (Ketac, E. Fil and E. Forte at 7, 21 and 63 days) and 3 controls (empty polyethylene tubes at 7, 21 and 63 days). After the experimental periods, the subcutaneous connective tissue surrounding the implanted material was removed and subjected to histotechnical processing and staining with hematoxylin and eosin. A histopathological description of the tissue reaction surrounding each material and a semi-quantitative analysis of collagen fiber formation and inflammatory infiltrate were performed. Additionally, the thickness of the granulomatous tissue in contact with each material was measured. Data were analyzed statistically (α=0.05) by the Kruskal-Wallis test, followed by Dunn post-test. Initially, the collagen fiber formation was not different among all the tested materials (p>0.05) but was different at 21 days with the control group presenting the most advanced stage of collagen fiber formation. At 63 days, EQUIA® Forte Fil group showed the most advanced stage of collagen fiber formation, compared to EQUIA® Fil group (p<0.05). The inflammatory infiltrate was not different among the tested materials in any experimental period (p>0.05). The thickness of the granulomatous tissue was greater in the E. Forte group, compared to control in all periods. All glass ionomer-based cements showed tissue compatibility, according to the evaluated parameters.


Resumo O objetivo deste estudo foi avaliar a resposta subcutânea do tecido conjuntivo de camundongos isogênicos após o implante de diferentes cimentos à base de ionômero de vidro (EQUIA® Forte Fil, EQUIA® Fil e Ketac ™ Universal Aplicap ™). Oitenta e sete camundongos isogênicos BALB/c foram alocados em 12 grupos, 9 como grupos experimentais (Ketac, E. Fil e E. Forte aos 7, 21 e 63 dias) e 3 controles (tubos de polietileno vazios aos 7, 21 e 63 dias). Após os períodos experimentais, o tecido conjuntivo subcutâneo ao redor do material implantado foi removido e submetido ao processamento histotécnico e coloração com hematoxilina e eosina. Uma descrição histopatológica da reação tecidual envolvendo cada material e uma análise semi-quantitativa da fibrose e infiltrado inflamatório foram realizadas. Além disso, foi realizada a mensuração da espessura do tecido granulomatoso em contato com cada material. Os dados foram analisados estatisticamente (α=0,05) pelo teste de Kruskal-Wallis, seguido do pós-teste de Dunn. Inicialmente, a fibrose não foi diferente entre todos os materiais testados (p>0,05), mas foi diferente aos 21 dias, com o grupo controle apresentando o estágio mais avançado de fibrose. Aos 63 dias, o grupo EQUIA® Forte Fil apresentou o estágio mais avançado de fibrose, comparado ao grupo EQUIA® Fil (p<0,05). O infiltrado inflamatório não foi diferente entre os materiais testados em nenhum período experimental (p>0,05). A espessura do tecido granulomatoso foi maior no grupo E. Forte, comparado ao controle em todos os períodos. Todos os cimentos à base de ionômero de vidro apresentaram compatibilidade tecidual, de acordo com os parâmetros avaliados.


Subject(s)
Animals , Rabbits , Acrylic Resins , Glass Ionomer Cements , Materials Testing , Silicon Dioxide , Mice, Inbred BALB C
11.
Article in English | WPRIM | ID: wpr-742074

ABSTRACT

PURPOSE: The aim of this study was to identify the effects of three aesthetic restorative materials on the wear between tooth and restoration by a pin-on-disk manner. MATERIALS AND METHODS: Six aesthetic restorative materials were used to prepare disk specimens for wear test, which were Lava Zirconia as zirconia group, Vintage MP and Cerabien ZR as veneering porcelain group, Gradia Direct microhybrid composite containing prepolymerized fillers, Filtek Z250 microhybrid composite containing zirconia glass and colloidal silica particles, and Filtek Z350 nanocomposite as composite resin group. Vertical loss of the worn cusp, change of the surface roughness of the restoration materials, and the surface topography were investigated after wear test under 9.8-N contact load. RESULTS: The porcelain groups (Vintage MP and Cerabien ZR) caused the largest vertical loss of teeth when compared with those of the composite resin and zirconia groups, and Filtek Z250 microhybrid composite results in the second-largest vertical loss of teeth. The surface of Filtek Z350 nanocomposite was deeply worn out, but visible wear on the surface of the zirconia and Gradia Direct microhybrid composite was not observed. When the zirconia surface was roughened by sand-blasting, vertical loss of teeth considerably increased when compared with that in the case of fine polished zirconia. CONCLUSION: It was identified that microhybrid composite resin containing a prepolymerized filler and zirconia with reduced surface roughness by polishing were the most desirable restorative materials among the tested materials to prevent the two-body wear between aesthetic restorative material and tooth.


Subject(s)
Colloids , Dental Enamel , Dental Porcelain , Glass , In Vitro Techniques , Nanocomposites , Silicon Dioxide , Tooth , Tooth Abrasion
12.
Article in English | WPRIM | ID: wpr-761911

ABSTRACT

BACKGROUND: Silica particles (SPs) induce cell proliferation and osteogenic differentiation. We reported that SPs in the scaffold induced early stage osteogenic differentiation. METHODS: A polycaprolactone (PCL) scaffold was fabricated with a 10 wt% SPs. The surface of PCL scaffold was coated with a 10 µg/mL collagen solution. Next, the scaffold was conjugated with 2 µM SPs, 2 µg/mL bone morphogenetic protein 2 (BMP2), or 2 µM BMP2-conjugated SPs (BCSPs). Green fluorescent protein-coupled BMP2 was applied to fabricate the scaffold. The fluorescence intensity was analyzed by confocal microscopy. The mRNA levels of the early osteogenic differentiation marker, alkaline phosphatase (ALP), were analyzed by real-time quantitative polymerase chain reaction. Levels of BMP2, RUNX2, ERK1/2, and AKT were assessed by western blotting. RESULTS: ALP mRNA levels were significantly higher in the BCSP-conjugated scaffold than in the other scaffolds. In the early stage of osteogenic differentiation, the protein levels of BMP2, RUNX2, ERK1/2, and AKT in cells were significantly higher in the BCSP-conjugated scaffold than in other scaffolds. Thus, the BCSP composite scaffold induced rapid osteogenic differentiation. CONCLUSION: These results suggest that BCSP composite can be used to promote early stage osteogenic differentiation and show promise as a material for use in scaffolds for bone regeneration.


Subject(s)
Alkaline Phosphatase , Blotting, Western , Bone Morphogenetic Protein 2 , Bone Morphogenetic Proteins , Bone Regeneration , Cell Proliferation , Collagen , Fluorescence , Microscopy, Confocal , Polymerase Chain Reaction , RNA, Messenger , Silicon Dioxide , Stem Cells
13.
Article in English | WPRIM | ID: wpr-761894

ABSTRACT

BACKGROUND: Lonocyte-derived multipotential cells (MOMCs) include progenitors capable of differentiation into multiple cell lineages and thus represent an ideal autologous transplantable cell source for regenerative medicine. In this study, we cultured MOMCs, generated from mononuclear cells of peripheral blood, on the surface of nanocomposite thin films. METHODS: For this purpose, nanocomposite Poly(e-caprolactone) (PCL)-based thin films containing either 2.5 wt% silica nanotubes (SiO2ntbs) or strontium hydroxyapatite nanorods (SrHAnrds), were prepared using the spin-coating method. The induced differentiation capacity of MOMCs, towards bone and endothelium, was estimated using flow cytometry, real-time polymerase chain reaction, scanning electron microscopy and fluorescence microscopy after cells' genetic modification using the Sleeping Beauty Transposon System aiming their observation onto the scaffolds. Moreover, Wharton's Jelly Mesenchymal Stromal Cells were cultivated as a control cell line, while Human Umbilical Vein Endothelial Cells were used to strengthen and accelerate the differentiation procedure in semi-permeable culture systems. Finally, the cytotoxicity of the studied materials was checked with MTT assay. RESULTS: The highest differentiation capacity of MOMCs was observed on PCL/SiO2ntbs 2.5 wt% nanocomposite film, as they progressively lost their native markers and gained endothelial lineage, in both protein and transcriptional level. In addition, the presence of SrHAnrds in the PCL matrix triggered processes related to osteoblast bone formation. CONCLUSION: To conclude, the differentiation of MOMCs was selectively guided by incorporating SiO2ntbs or SrHAnrds into a polymeric matrix, for the first time.


Subject(s)
Autografts , Beauty , Cell Line , Cell Lineage , Durapatite , Endothelium , Flow Cytometry , Human Umbilical Vein Endothelial Cells , Mesenchymal Stem Cells , Methods , Microscopy, Electron, Scanning , Microscopy, Fluorescence , Nanocomposites , Nanotubes , Osteoblasts , Osteogenesis , Polymers , Real-Time Polymerase Chain Reaction , Regenerative Medicine , Silicon Dioxide , Strontium , Wharton Jelly
14.
Article in English | WPRIM | ID: wpr-761416

ABSTRACT

PURPOSE: The aim of the present study was to evaluate the color changes of an autopolymerizing PMMA resin used for interim fixed restorations, reinforced with SiO2 nanoparticles. MATERIALS AND METHODS: Silica nanoparticles were blended with the PMMA resin powder through high-energy ball milling. Four shades of PMMA resin were used (A3, B3, C3, D3) and total color differences were calculated through the equations ΔEab= [(ΔL*)2 + (Δa*)2 + (Δb*)2]½ and Δ E 00 = [ Δ L ′ K L S L 2 + Δ C ′ K C S C 2 + Δ H ′ K H S H 2 + R T Δ C ′ K C S C Δ H ′ K H S H ] 1 / 2 . Statistically significant differences between ΔEab and the clinically acceptable values of 3.3 and 2.7 and those between ΔE00 and the clinically acceptable value of 1.8 were evaluated with one sample t-test (P<.05). Differences among the different shades were assessed through One-Way ANOVA and Bonferroni multiple comparison tests. RESULTS: Significantly lower values were detected for all groups concerning ΔEab compared to the intraorally clinical acceptable values of 3.3 and 2.7. Significantly lower mean values were detected for groups B3, C3, and D3, concerning ΔE00 compared to the intraorally clinical acceptant value of 1.8. Color pigments in red-brown (A3) and red-grey (D3) shades affect the total color change to a greater extent after the reinforcement with SiO2 nanoparticles compared to the red-yellow (B3) shade. CONCLUSION: Within the limitations of this in vitro study, it can be suggested that reinforcing PMMA with SiO2 nanoparticles at 0.25 wt% slightly affects the optical properties of the PMMA resin without being clinically perceivable.


Subject(s)
In Vitro Techniques , Nanoparticles , Polymethyl Methacrylate , Prostheses and Implants , Silicon Dioxide
15.
Article in English | WPRIM | ID: wpr-761412

ABSTRACT

PURPOSE: The purpose of this study was to evaluate the shear bond strength (SBS) of an indirect resin composite (IRC) to the various resin matrix ceramic (RMC) blocks using different surface treatments. MATERIALS AND METHODS: Ninety-nine cubic RMC specimens consisting of a resin nanoceramic (RNC), a polymer-infiltrated hybrid ceramic (PIHC), and a flexible hybrid ceramic (FHC) were divided randomly into three surface treatment subgroups (n = 11). In the experimental groups, untreated (Cnt), tribochemical silica coating (Tbc), and Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) laser irradiation (Lsr) with 3 W (150 mJ/pulse, 20 Hz for 20 sec.) were used as surface treatments. An indirect composite resin (IRC) was layered with a disc-shape mold (2 × 3 mm) onto the treated-ceramic surfaces and the specimens submitted to thermal cycling (6000 cycles, 5 – 55℃). The SBS test of specimens was performed using a universal testing machine and the specimens were examined with a scanning electron microscope to determine the failure mode. Data were statistically analyzed with two-way analysis of variance (ANOVA) and Tukey HSD test (α=.05). RESULTS: According to the two-way ANOVA, only the surface treatment parameter was statistically significant (P<.05) on the SBS of IRC to RMC. The SBS values of Lsr-applied RMC groups were significantly higher than Cnt groups for each RMC material, (P<.05). Significant differences were also determined between Tbc surface treatment applied and untreated (Cnt) PIHC materials (P=.039). CONCLUSION: For promoting a reliable bond strength during characterization of RMC with IRC, Nd:YAG laser or Tbc surface treatment technique should be used, putting in consideration the microstructure and composition of RMC materials and appropriate parameters for each material.


Subject(s)
Aluminum , Ceramics , Composite Resins , Fungi , Shear Strength , Silicon Dioxide , Yttrium
16.
Article in Chinese | WPRIM | ID: wpr-813045

ABSTRACT

To analyze the differential expression of RAW264.7 macrophage-derived exosomes miRNA stimulated by free silicon dioxide (SiO2).
 Methods: RAW264.7 was stimulated with SiO2 (200 mg/L) for 48 h (exo_48 h group), and the supernatant was collected. The exosomes in the supernatant were extracted by ultracentrifugation. Transmission microscopy, nanoparticle tracking analysis (NTA) and Western blotting were used to identify exosomes. High-throughput sequencing was performed to compare the differential expression of exosome miRNAs between the exo_control group (RAW264.7 cultured for 48 h without SiO2) and the exo_48 h group; miRanda, TargetScan and starBase were used to predict target genes of differential miRNAs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed on target genes to further analyze the biological functions of genes.
 Results: The transmission microscopy showed that the exosomes were lipid membrane coated vesicles, which were heterogeneously distributed, with a diameter ranging from 30 to 100 nm, and the shape was round or elliptical. The volume kurtosis was concentrated between 40 and 100 nm and the exosome marker protein TSG101 was positive. High-throughput sequencing screened 148 differentially expressed exosomal miRNAs. MiR-219c-3p, let-7d-3p, let-7a-1-3p, miR-328-3p, miR-365-3p, and miR-7219-3p were significantly up-regulated, and miR-378d and miR-5106 were significantly down-regulated compared with the control group. Target genes were mainly enriched in mTOR signaling pathway, Wnt signaling pathway, TGF-β signaling pathway, and so on.
 Conclusion: The exosomes secreted by SiO2-induced macrophages contain abundant miRNAs, and their expressions are significantly different. These differential miRNAs may be involved in the activation of lung fibroblasts and epithelial-mesenchymal transition.


Subject(s)
Animals , Cell Line , Exosomes , High-Throughput Nucleotide Sequencing , Macrophages , Mice , MicroRNAs , Silicon Dioxide
17.
Rev. bras. med. trab ; 16(3): 378-386, out.2018.
Article in English, Portuguese | LILACS | ID: biblio-966086

ABSTRACT

Introdução: A relação entre a sílica e o tabaco como potencializadores na geração de fibrose pulmonar não foi ainda bem estabelecida, embora tenham sido postulados alguns mecanismos fisiopatológicos para embasá-la. É necessário reconhecer o papel das diversas células envolvidas na resposta inflamatória, assim como as diversas vias biológicas que participam na gênese. Esses fatores nos motivaram a desenvolver a presente revisão descritiva. Resultados: Cada vez mais evidências sugerem que a inflamação local produzida por exposição à sílica e à fumaça do tabaco pode ser modulada por fatores genéticos, mecanismos epigenéticos, reações autoimunes e hipóxia local, levando à transição epitélio-mesênquima e ao acúmulo de material necrótico no pulmão, o que contribui à perpetuação da inflamação e a uma resposta imunológica inata exagerada nos trabalhadores com silicose fumantes. Conclusão: Comparações diretas de diferentes estudos de mensuração de biomarcadores inflamatórios associados à silicose e ao tabagismo devem ser realizadas com cautela, devido a uma série de possíveis fatores de confusão, como compartimentalização ou interação com as diversas vias biológicas e tipos celulares envolvidos. Convém destacar que para se evitar a ocorrência de dano pulmonar nos trabalhadores expostos à sílica, devem-se melhorar os sistemas de ventilação e reduzir sua exposição. No contexto da cessação do tabagismo, é necessário o uso de componentes psicoterapêuticos, com o fim de evitar o dano pulmonar precocemente


Background: The relationship between silica dust and tobacco smoking as enhancers of pulmonary fibrosis development has not yet been well established. Some pathophysiological mechanisms which might support this relationship were postulated. The role of different cells involved in the inflammatory response, and of different biological pathways needs to be recognized. These facts encouraged us to perform the present descriptive review. Results: Growing evidence suggests that local inflammation induced by exposure to silica dust and tobacco smoking might be modulated by genetic factors, epigenetic mechanisms, autoimmune reactions and local hypoxia, giving rise to the epithelial­mesenchymal transition. These phenomena lead to accumulation of necrotic material in the lungs, which contributes to inflammation's perpetuation and to an exaggerated innate immunological response among workers with silicosis who smoke. Conclusion: Direct comparisons of different measurement studies of inflammatory biomarkers associated with silicosis and tobacco smoking should be performed cautiously due to several possible confounding factors, such as compartmentalization or interaction among the various biological pathways and cell types involved. Ventilation systems should be improved and exposure reduced to prevent lung damage in workers exposed to silica. In regard to smoking cessation, psychotherapy approaches are needed for early prevention of lung damage


Subject(s)
Pulmonary Fibrosis/prevention & control , Silicosis , Tobacco Use Disorder , Biomarkers , Silicon Dioxide/adverse effects
18.
Cienc. Trab ; 20(62): 90-96, ago. 2018. tab, graf
Article in Spanish | LILACS | ID: biblio-974653

ABSTRACT

Resumen: Introducción: La silicosis es una enfermedad pulmonar progresiva, irreversible, pero potencialmente prevenible. Conocer la percepción de riesgo en trabajadores expuestos a sílice es necesario para intervenir y reducir la incidencia de silicosis y otras enfermedades relacionadas. El objetivo de este estudio fue validar un Cuestionario de Percepción de Riesgo de Exposición Ocupacional a Sílice (CuPREOS) en trabajadores expuestos, en distintas actividades laborales en Temuco, Chile. Material y método: Una etapa de exploración con enfoque fenomenológico/ naturalista permitió conformar categorías de primer y segundo orden, que concluyó en una primera versión del instrumento. Una segunda etapa incluyó análisis factorial exploratorio y confirmatorio. Resultados: Se develaron dos dimensiones subyacentes: a) evidencia de riesgo, en la que el trabajador manifiesta evaluar señales de alarma y b) ausencia de riesgo, en la que sopesa aspectos que contrarrestan las anteriores. Ambas configuran la estructura conceptual que conforma el CuPREOS de 9 ítems/preguntas, con una confiabilidad de 0.84 (alfa Cronbach). Los indicadores del análisis confirmatorio revelan un buen ajuste del mode lo. Discusión: la percepción de riesgo es un constructo que involucra complejidades sociales y culturales, su medición debe ser sencilla y práctica; su conocimiento permitiría decisiones más efectivas en pre vención e intervención.


Abstract: Introduction: Silicosis is a progressive lung disease, irreversible, but potentially preventable. Knowing the perception of risk in workers exposed to silica is necessary to intervene and reduce the incidence of silicosis and other related diseases. The objective of this study was to validate a Questionnaire of risk perception of occupational expo sure to silica (CuPREOS) in exposed workers, in different work activities in Temuco, Chile. Material and method: A stage of explo ration with phenomenological/naturalist approach allowed to create categories of first and second order, which ended in a first version of the instrument. The second stage included exploratory and con firmatory factor analysis. Results: two underlying dimensions were revealed: a) evidence of risk, in which worker states to evaluate signals of alarm and b) absence of risk, in which he weighs aspects that counteract the previous ones. Both set up the conceptual frame work that sustain the CuPREOS of 9 items/questions, with a reliabil ity of 0.84 (Cronbach alfa). The confirmatory analysis indicators show a good fit of the model. Discussion: the perception of risk is a construct involving social and cultural complexities, its measurement should be simple and practical; its knowledge would enable more effective decision-making in prevention and intervention.


Subject(s)
Humans , Free Silica/adverse effects , Surveys and Questionnaires , Occupational Exposure , Risk Assessment/methods , Perception , Silicosis/etiology , Occupational Risks , Chile , Reproducibility of Results , Risk Factors , Factor Analysis, Statistical , Silicon Dioxide
20.
Rev. am. med. respir ; 18(1): 61-64, mar. 2018. ilus
Article in Spanish | LILACS | ID: biblio-897308

ABSTRACT

La neumoconiosis constituye un grupo de enfermedades asociadas con la exposición e inhalación de polvo mineral, de partículas inorgánicas, sílice, berilio, carbón, cobalto, talco, etc. La exposición al polvo de sílice se asocia no sólo con silicosis, sino también con enfermedad pulmonar obstructiva crónica, cáncer de pulmón, insuficiencia renal y riesgo aumentado de tuberculosis pulmonar y enfermedades autoinmunes. Está bien establecida la asociación entre el contacto con el sílice por vía inhalatoria y enfermedades autoinmunes, particularmente en el contexto de una exposición intensa. La exposición al sílice se ha vinculado con un incremento de la síntesis de anticuerpos y complejos inmunes, aún sin la presencia de características clínicas de enfermedad autoinmune. El riesgo de desarrollar esclerosis sistémica, artritis reumatoidea, lupus eritematoso sistémico, dermatomiositis / polimiositis y anticuerpos anticitoplasmáticos del neutrófilo (ANCA) positivos (vasculitis) esta descripto en varios estudios. En paciente que trabajan en canteras con escasas medidas de prevención el desarrollo de silicosis ha llegado ser tan severo que ha requerido trasplante pulmonar; sobre esta base se recomienda seguirlos con un perfil inmunológico como control o estar atentos a otras manifestaciones de autoinmunidad. La esclerosis sistémica es una enfermedad autoinmune definida como un desorden generalizado de la microvasculatura y del tejido conectivo, con engrosamiento y obliteración de los vasos arteriales de piel, pulmón, tracto gastrointestinal, corazón y riñones. Su etiología es desconocida pero probablemente concurren factores endógenos y exógenos. Entre los factores exógenos, la exposición ocupacional juega un rol importante como causa potencial, incluyendo el polvo de sílice, cloruro de vinilo, resina epoxi, bleomicina, hidrocarburos aromáticos, aceites. Excepto el s-lice todos los otros agentes producen cambios reversibles una vez suspendido el contacto con el agente. El polvo de sílice y su inhalación es un factor de riesgo bien reconocido de esclerosis sistémica. Las partículas de cristal de sílice (cuarzo) que miden menos de un micrometro son las más patogénicas ya que al ser inertes pueden permanecer por tiempo indeterminado en el tejido. El antecedente de exposición al polvo de sílice y esclerosis sistémica se conoce como Síndrome de Erasmus.


Subject(s)
Pneumoconiosis , Silicosis , Silicon Dioxide
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